diff options
| author |  Mike Klein <mtklein@chromium.org> | 2017-09-19 13:30:58 -0400 |
|---|---|---|
| committer |  Skia Commit-Bot <skia-commit-bot@chromium.org> | 2017-09-19 19:33:09 +0000 |
| commit | 6b6674d321ef059bf9b1b7f0be39737d880fa428 (patch) | |
| tree | 2cd1910117b58b83f9ad4e66c7db8a35b744e3ec /third_party/libpng | |
| parent | 10501885de057c155195bcbd1dd18d9cd16f59ac (diff) | |
libpng: update to 1.6.32, pull using DEPS
I'd have done this as two steps, but we didn't have a pure copy of
libpng to start with. The patches we did have, though, have been
upstreamed and are now unneeded.
Change-Id: I884b9bc47afe5000f5a521f66a3bb95c0411b39a
Reviewed-on: https://skia-review.googlesource.com/48620
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Diffstat (limited to 'third_party/libpng')
38 files changed, 31 insertions, 47924 deletions
diff --git a/third_party/libpng/BUILD.gn b/third_party/libpng/BUILD.gn index 6a4c65732c..a01ede6501 100644 --- a/third_party/libpng/BUILD.gn +++ b/third_party/libpng/BUILD.gn @@ -15,42 +15,45 @@ if (skia_use_system_libpng) { } } else { third_party("libpng") { - public_include_dirs = [ "." ] + public_include_dirs = [ + ".", + "../externals/libpng", + ] defines = [] deps = [ "//third_party/zlib", ] sources = [ - "png.c", - "pngerror.c", - "pngget.c", - "pngmem.c", - "pngpread.c", - "pngread.c", - "pngrio.c", - "pngrtran.c", - "pngrutil.c", - "pngset.c", - "pngtrans.c", - "pngwio.c", - "pngwrite.c", - "pngwtran.c", - "pngwutil.c", + "../externals/libpng/png.c", + "../externals/libpng/pngerror.c", + "../externals/libpng/pngget.c", + "../externals/libpng/pngmem.c", + "../externals/libpng/pngpread.c", + "../externals/libpng/pngread.c", + "../externals/libpng/pngrio.c", + "../externals/libpng/pngrtran.c", + "../externals/libpng/pngrutil.c", + "../externals/libpng/pngset.c", + "../externals/libpng/pngtrans.c", + "../externals/libpng/pngwio.c", + "../externals/libpng/pngwrite.c", + "../externals/libpng/pngwtran.c", + "../externals/libpng/pngwutil.c", ] if (current_cpu == "arm" || current_cpu == "arm64") { sources += [ - "arm/arm_init.c", - "arm/filter_neon_intrinsics.c", + "../externals/libpng/arm/arm_init.c", + "../externals/libpng/arm/filter_neon_intrinsics.c", ] } if (current_cpu == "x86" || current_cpu == "x64") { defines += [ "PNG_INTEL_SSE" ] sources += [ - "contrib/intel/filter_sse2_intrinsics.c", - "contrib/intel/intel_init.c", + "../externals/libpng/intel/filter_sse2_intrinsics.c", + "../externals/libpng/intel/intel_init.c", ] } } diff --git a/third_party/libpng/LICENSE b/third_party/libpng/LICENSE deleted file mode 100644 index dcb348251e..0000000000 --- a/third_party/libpng/LICENSE +++ /dev/null @@ -1,130 +0,0 @@ - -This copy of the libpng notices is provided for your convenience. In case of -any discrepancy between this copy and the notices in the file png.h that is -included in the libpng distribution, the latter shall prevail. - -COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: - -If you modify libpng you may insert additional notices immediately following -this sentence. - -This code is released under the libpng license. - -libpng versions 1.0.7, July 1, 2000 through 1.6.22rc01, May 14, 2016 are -Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are -derived from libpng-1.0.6, and are distributed according to the same -disclaimer and license as libpng-1.0.6 with the following individuals -added to the list of Contributing Authors: - - Simon-Pierre Cadieux - Eric S. Raymond - Mans Rullgard - Cosmin Truta - Gilles Vollant - James Yu - -and with the following additions to the disclaimer: - - There is no warranty against interference with your enjoyment of the - library or against infringement. There is no warranty that our - efforts or the library will fulfill any of your particular purposes - or needs. This library is provided with all faults, and the entire - risk of satisfactory quality, performance, accuracy, and effort is with - the user. - -Some files in the "contrib" directory and some configure-generated -files that are distributed with libpng have other copyright owners and -are released under other open source licenses. - -libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are -Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from -libpng-0.96, and are distributed according to the same disclaimer and -license as libpng-0.96, with the following individuals added to the list -of Contributing Authors: - - Tom Lane - Glenn Randers-Pehrson - Willem van Schaik - -libpng versions 0.89, June 1996, through 0.96, May 1997, are -Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, -and are distributed according to the same disclaimer and license as -libpng-0.88, with the following individuals added to the list of -Contributing Authors: - - John Bowler - Kevin Bracey - Sam Bushell - Magnus Holmgren - Greg Roelofs - Tom Tanner - -Some files in the "scripts" directory have other copyright owners -but are released under this license. - -libpng versions 0.5, May 1995, through 0.88, January 1996, are -Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. - -For the purposes of this copyright and license, "Contributing Authors" -is defined as the following set of individuals: - - Andreas Dilger - Dave Martindale - Guy Eric Schalnat - Paul Schmidt - Tim Wegner - -The PNG Reference Library is supplied "AS IS". The Contributing Authors -and Group 42, Inc. disclaim all warranties, expressed or implied, -including, without limitation, the warranties of merchantability and of -fitness for any purpose. The Contributing Authors and Group 42, Inc. -assume no liability for direct, indirect, incidental, special, exemplary, -or consequential damages, which may result from the use of the PNG -Reference Library, even if advised of the possibility of such damage. - -Permission is hereby granted to use, copy, modify, and distribute this -source code, or portions hereof, for any purpose, without fee, subject -to the following restrictions: - - 1. The origin of this source code must not be misrepresented. - - 2. Altered versions must be plainly marked as such and must not - be misrepresented as being the original source. - - 3. This Copyright notice may not be removed or altered from any - source or altered source distribution. - -The Contributing Authors and Group 42, Inc. specifically permit, without -fee, and encourage the use of this source code as a component to -supporting the PNG file format in commercial products. If you use this -source code in a product, acknowledgment is not required but would be -appreciated. - -END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. - -TRADEMARK: - -The name "libpng" has not been registered by the Copyright owner -as a trademark in any jurisdiction. However, because libpng has -been distributed and maintained world-wide, continually since 1995, -the Copyright owner claims "common-law trademark protection" in any -jurisdiction where common-law trademark is recognized. - -OSI CERTIFICATION: - -Libpng is OSI Certified Open Source Software. OSI Certified Open Source is -a certification mark of the Open Source Initiative. OSI has not addressed -the additional disclaimers inserted at version 1.0.7. - -EXPORT CONTROL: - -The Copyright owner believes that the Export Control Classification -Number (ECCN) for libpng is EAR99, which means not subject to export -controls or International Traffic in Arms Regulations (ITAR) because -it is open source, publicly available software, that does not contain -any encryption software. See the EAR, paragraphs 734.3(b)(3) and -734.7(b). - -Glenn Randers-Pehrson -glennrp at users.sourceforge.net -May 14, 2016 diff --git a/third_party/libpng/README b/third_party/libpng/README deleted file mode 100644 index 10eb805aaf..0000000000 --- a/third_party/libpng/README +++ /dev/null @@ -1,215 +0,0 @@ -README for libpng version 1.6.22rc01 - May 14, 2016 (shared library 16.0) -See the note about version numbers near the top of png.h - -See INSTALL for instructions on how to install libpng. - -Libpng comes in several distribution formats. Get libpng-*.tar.gz or -libpng-*.tar.xz or if you want UNIX-style line endings in the text files, -or lpng*.7z or lpng*.zip if you want DOS-style line endings. - -Version 0.89 was the first official release of libpng. Don't let the -fact that it's the first release fool you. The libpng library has been in -extensive use and testing since mid-1995. By late 1997 it had -finally gotten to the stage where there hadn't been significant -changes to the API in some time, and people have a bad feeling about -libraries with versions < 1.0. Version 1.0.0 was released in -March 1998. - -**** -Note that some of the changes to the png_info structure render this -version of the library binary incompatible with libpng-0.89 or -earlier versions if you are using a shared library. The type of the -"filler" parameter for png_set_filler() has changed from png_byte to -png_uint_32, which will affect shared-library applications that use -this function. - -To avoid problems with changes to the internals of png info_struct, -new APIs have been made available in 0.95 to avoid direct application -access to info_ptr. These functions are the png_set_<chunk> and -png_get_<chunk> functions. These functions should be used when -accessing/storing the info_struct data, rather than manipulating it -directly, to avoid such problems in the future. - -It is important to note that the APIs did not make current programs -that access the info struct directly incompatible with the new -library, through libpng-1.2.x. In libpng-1.4.x, which was meant to -be a transitional release, members of the png_struct and the -info_struct can still be accessed, but the compiler will issue a -warning about deprecated usage. Since libpng-1.5.0, direct access -to these structs is not allowed, and the definitions of the structs -reside in private pngstruct.h and pnginfo.h header files that are not -accessible to applications. It is strongly suggested that new -programs use the new APIs (as shown in example.c and pngtest.c), and -older programs be converted to the new format, to facilitate upgrades -in the future. -**** - -Additions since 0.90 include the ability to compile libpng as a -Windows DLL, and new APIs for accessing data in the info struct. -Experimental functions include the ability to set weighting and cost -factors for row filter selection, direct reads of integers from buffers -on big-endian processors that support misaligned data access, faster -methods of doing alpha composition, and more accurate 16->8 bit color -conversion. - -The additions since 0.89 include the ability to read from a PNG stream -which has had some (or all) of the signature bytes read by the calling -application. This also allows the reading of embedded PNG streams that -do not have the PNG file signature. As well, it is now possible to set -the library action on the detection of chunk CRC errors. It is possible -to set different actions based on whether the CRC error occurred in a -critical or an ancillary chunk. - -The changes made to the library, and bugs fixed are based on discussions -on the PNG-implement mailing list and not on material submitted -privately to Guy, Andreas, or Glenn. They will forward any good -suggestions to the list. - -For a detailed description on using libpng, read libpng-manual.txt. For -examples of libpng in a program, see example.c and pngtest.c. For usage -information and restrictions (what little they are) on libpng, see -png.h. For a description on using zlib (the compression library used by -libpng) and zlib's restrictions, see zlib.h - -I have included a general makefile, as well as several machine and -compiler specific ones, but you may have to modify one for your own needs. - -You should use zlib 1.0.4 or later to run this, but it MAY work with -versions as old as zlib 0.95. Even so, there are bugs in older zlib -versions which can cause the output of invalid compression streams for -some images. You will definitely need zlib 1.0.4 or later if you are -taking advantage of the MS-DOS "far" structure allocation for the small -and medium memory models. You should also note that zlib is a -compression library that is useful for more things than just PNG files. -You can use zlib as a drop-in replacement for fread() and fwrite() if -you are so inclined. - -zlib should be available at the same place that libpng is, or at zlib.net. - -You may also want a copy of the PNG specification. It is available -as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find -these at http://www.libpng.org/pub/png/documents/ - -This code is currently being archived at libpng.sf.net in the -[DOWNLOAD] area, and at ftp://ftp.simplesystems.org. If you can't find it -in any of those places, e-mail me, and I'll help you find it. - -I am not a lawyer, but I believe that the Export Control Classification -Number (ECCN) for libpng is EAR99, which means not subject to export -controls or International Traffic in Arms Regulations (ITAR) because it -is open source, publicly available software, that does not contain any -encryption software. See the EAR, paragraphs 734.3(b)(3) and 734.7(b). - -If you have any code changes, requests, problems, etc., please e-mail -them to me. Also, I'd appreciate any make files or project files, -and any modifications you needed to make to get libpng to compile, -along with a #define variable to tell what compiler/system you are on. -If you needed to add transformations to libpng, or wish libpng would -provide the image in a different way, drop me a note (and code, if -possible), so I can consider supporting the transformation. -Finally, if you get any warning messages when compiling libpng -(note: not zlib), and they are easy to fix, I'd appreciate the -fix. Please mention "libpng" somewhere in the subject line. Thanks. - -This release was created and will be supported by myself (of course -based in a large way on Guy's and Andreas' earlier work), and the PNG -development group. - -Send comments/corrections/commendations to png-mng-implement at -lists.sourceforge.net (subscription required; visit -https://lists.sourceforge.net/lists/listinfo/png-mng-implement -to subscribe) or to glennrp at users.sourceforge.net - -You can't reach Guy, the original libpng author, at the addresses -given in previous versions of this document. He and Andreas will -read mail addressed to the png-implement list, however. - -Please do not send general questions about PNG. Send them to -png-mng-misc at lists.sf.net (subscription required; visit -https://lists.sourceforge.net/lists/listinfo/png-mng-misc to -subscribe). If you have a question about something -in the PNG specification that is related to using libpng, send it -to me. Send me any questions that start with "I was using libpng, -and ...". If in doubt, send questions to me. I'll bounce them -to others, if necessary. - -Please do not send suggestions on how to change PNG. We have -been discussing PNG for twenty years now, and it is official and -finished. If you have suggestions for libpng, however, I'll -gladly listen. Even if your suggestion is not used immediately, -it may be used later. - -Files in this distribution: - - ANNOUNCE => Announcement of this version, with recent changes - CHANGES => Description of changes between libpng versions - KNOWNBUG => List of known bugs and deficiencies - LICENSE => License to use and redistribute libpng - README => This file - TODO => Things not implemented in the current library - Y2KINFO => Statement of Y2K compliance - example.c => Example code for using libpng functions - libpng.3 => manual page for libpng (includes libpng-manual.txt) - libpng-manual.txt => Description of libpng and its functions - libpngpf.3 => manual page for libpng's private functions - png.5 => manual page for the PNG format - png.c => Basic interface functions common to library - png.h => Library function and interface declarations (public) - pngpriv.h => Library function and interface declarations (private) - pngconf.h => System specific library configuration (public) - pngstruct.h => png_struct declaration (private) - pnginfo.h => png_info struct declaration (private) - pngdebug.h => debugging macros (private) - pngerror.c => Error/warning message I/O functions - pngget.c => Functions for retrieving info from struct - pngmem.c => Memory handling functions - pngbar.png => PNG logo, 88x31 - pngnow.png => PNG logo, 98x31 - pngpread.c => Progressive reading functions - pngread.c => Read data/helper high-level functions - pngrio.c => Lowest-level data read I/O functions - pngrtran.c => Read data transformation functions - pngrutil.c => Read data utility functions - pngset.c => Functions for storing data into the info_struct - pngtest.c => Library test program - pngtest.png => Library test sample image - pngtrans.c => Common data transformation functions - pngwio.c => Lowest-level write I/O functions - pngwrite.c => High-level write functions - pngwtran.c => Write data transformations - pngwutil.c => Write utility functions - arm => Contains optimized code for the ARM platform - contrib => Contributions - examples => Example programs - gregbook => source code for PNG reading and writing, from - Greg Roelofs' "PNG: The Definitive Guide", - O'Reilly, 1999 - libtests => Test programs - pngminim => Minimal decoder, encoder, and progressive decoder - programs demonstrating use of pngusr.dfa - pngminus => Simple pnm2png and png2pnm programs - pngsuite => Test images - tools => Various tools - visupng => Contains a MSVC workspace for VisualPng - projects => Contains project files and workspaces for - building a DLL - owatcom => Contains a WATCOM project for building libpng - visualc71 => Contains a Microsoft Visual C++ (MSVC) - workspace for building libpng and zlib - vstudio => Contains a Microsoft Visual C++ (MSVC) - workspace for building libpng and zlib - scripts => Directory containing scripts for building libpng: - (see scripts/README.txt for the list of scripts) - -Good luck, and happy coding. - --Glenn Randers-Pehrson (current maintainer, since 1998) - Internet: glennrp at users.sourceforge.net - --Andreas Eric Dilger (former maintainer, 1996-1997) - Internet: adilger at enel.ucalgary.ca - Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/ - --Guy Eric Schalnat (original author and former maintainer, 1995-1996) - (formerly of Group 42, Inc) - Internet: gschal at infinet.com diff --git a/third_party/libpng/README.google b/third_party/libpng/README.google deleted file mode 100644 index b7153bd422..0000000000 --- a/third_party/libpng/README.google +++ /dev/null @@ -1,15 +0,0 @@ -URL: http://www.libpng.org/pub/png/libpng.html -Version: 1.6.22rc01 -License: libpng license -License File: LICENSE, pulled out of png.h -Description: png compression/decompression library -Local Modifications: - (1) Created pnglibconf.h from pnglibconf.h.prebuilt. This - is mostly a rename, with Skia-specific settings at the end. - The only difference is for pngprefix.h. - (2) Included Intel optimizations by running: - "patch -i contrib/intel/intel_sse.patch -p1" - (3) Removed files unused by Skia - (4) Fixed an undefined behavior bug (skbug.com/5390) - (5) Add pngprefix.h, so multiple versions of libpng can - coexist. diff --git a/third_party/libpng/arm/arm_init.c b/third_party/libpng/arm/arm_init.c deleted file mode 100644 index 3c01231741..0000000000 --- a/third_party/libpng/arm/arm_init.c +++ /dev/null @@ -1,135 +0,0 @@ - -/* arm_init.c - NEON optimised filter functions - * - * Copyright (c) 2014,2016 Glenn Randers-Pehrson - * Written by Mans Rullgard, 2011. - * Last changed in libpng 1.6.22 [(PENDING RELEASE)] - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ -/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are - * called. - */ -#define _POSIX_SOURCE 1 - -#include "../pngpriv.h" - -#ifdef PNG_READ_SUPPORTED - -#if PNG_ARM_NEON_OPT > 0 -#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */ -/* WARNING: it is strongly recommended that you do not build libpng with - * run-time checks for CPU features if at all possible. In the case of the ARM - * NEON instructions there is no processor-specific way of detecting the - * presence of the required support, therefore run-time detection is extremely - * OS specific. - * - * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing - * a fragment of C source code which defines the png_have_neon function. There - * are a number of implementations in contrib/arm-neon, but the only one that - * has partial support is contrib/arm-neon/linux.c - a generic Linux - * implementation which reads /proc/cpufino. - */ -#ifndef PNG_ARM_NEON_FILE -# ifdef __linux__ -# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c" -# endif -#endif - -#ifdef PNG_ARM_NEON_FILE - -#include <signal.h> /* for sig_atomic_t */ -static int png_have_neon(png_structp png_ptr); -#include PNG_ARM_NEON_FILE - -#else /* PNG_ARM_NEON_FILE */ -# error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks" -#endif /* PNG_ARM_NEON_FILE */ -#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */ - -#ifndef PNG_ALIGNED_MEMORY_SUPPORTED -# error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED" -#endif - -void -png_init_filter_functions_neon(png_structp pp, unsigned int bpp) -{ - /* The switch statement is compiled in for ARM_NEON_API, the call to - * png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined - * the check is only performed if the API has not set the NEON option on - * or off explicitly. In this case the check controls what happens. - * - * If the CHECK is not compiled in and the option is UNSET the behavior prior - * to 1.6.7 was to use the NEON code - this was a bug caused by having the - * wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF, - * as documented in png.h - */ - png_debug(1, "in png_init_filter_functions_neon"); -#ifdef PNG_ARM_NEON_API_SUPPORTED - switch ((pp->options >> PNG_ARM_NEON) & 3) - { - case PNG_OPTION_UNSET: - /* Allow the run-time check to execute if it has been enabled - - * thus both API and CHECK can be turned on. If it isn't supported - * this case will fall through to the 'default' below, which just - * returns. - */ -#endif /* PNG_ARM_NEON_API_SUPPORTED */ -#ifdef PNG_ARM_NEON_CHECK_SUPPORTED - { - static volatile sig_atomic_t no_neon = -1; /* not checked */ - - if (no_neon < 0) - no_neon = !png_have_neon(pp); - - if (no_neon) - return; - } -#ifdef PNG_ARM_NEON_API_SUPPORTED - break; -#endif -#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */ - -#ifdef PNG_ARM_NEON_API_SUPPORTED - default: /* OFF or INVALID */ - return; - - case PNG_OPTION_ON: - /* Option turned on */ - break; - } -#endif - - /* IMPORTANT: any new external functions used here must be declared using - * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the - * 'prefix' option to configure works: - * - * ./configure --with-libpng-prefix=foobar_ - * - * Verify you have got this right by running the above command, doing a build - * and examining pngprefix.h; it must contain a #define for every external - * function you add. (Notice that this happens automatically for the - * initialization function.) - */ - pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; - - if (bpp == 3) - { - pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; - pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth3_neon; - } - - else if (bpp == 4) - { - pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; - pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth4_neon; - } -} -#endif /* PNG_ARM_NEON_OPT > 0 */ -#endif /* READ */ diff --git a/third_party/libpng/arm/filter_neon.S b/third_party/libpng/arm/filter_neon.S deleted file mode 100644 index 3b061d6bbf..0000000000 --- a/third_party/libpng/arm/filter_neon.S +++ /dev/null @@ -1,253 +0,0 @@ - -/* filter_neon.S - NEON optimised filter functions - * - * Copyright (c) 2014 Glenn Randers-Pehrson - * Written by Mans Rullgard, 2011. - * Last changed in libpng 1.6.16 [December 22, 2014] - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -/* This is required to get the symbol renames, which are #defines, and the - * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION. - */ -#define PNG_VERSION_INFO_ONLY -#include "../pngpriv.h" - -#if defined(__linux__) && defined(__ELF__) -.section .note.GNU-stack,"",%progbits /* mark stack as non-executable */ -#endif - -#ifdef PNG_READ_SUPPORTED - -/* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for - * ARM64). The code in arm/filter_neon_intrinsics.c supports ARM64, however it - * only works if -mfpu=neon is specified on the GCC command line. See pngpriv.h - * for the logic which sets PNG_USE_ARM_NEON_ASM: - */ -#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */ - -#if PNG_ARM_NEON_OPT > 0 - -#ifdef __ELF__ -# define ELF -#else -# define ELF @ -#endif - - .arch armv7-a - .fpu neon - -.macro func name, export=0 - .macro endfunc -ELF .size \name, . - \name - .endfunc - .purgem endfunc - .endm - .text - - /* Explicitly specifying alignment here because some versions of - * GAS don't align code correctly. This is harmless in correctly - * written versions of GAS. - */ - .align 2 - - .if \export - .global \name - .endif -ELF .type \name, STT_FUNC - .func \name -\name: -.endm - -func png_read_filter_row_sub4_neon, export=1 - ldr r3, [r0, #4] @ rowbytes - vmov.i8 d3, #0 -1: - vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] - vadd.u8 d0, d3, d4 - vadd.u8 d1, d0, d5 - vadd.u8 d2, d1, d6 - vadd.u8 d3, d2, d7 - vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! - subs r3, r3, #16 - bgt 1b - - bx lr -endfunc - -func png_read_filter_row_sub3_neon, export=1 - ldr r3, [r0, #4] @ rowbytes - vmov.i8 d3, #0 - mov r0, r1 - mov r2, #3 - mov r12, #12 - vld1.8 {q11}, [r0], r12 -1: - vext.8 d5, d22, d23, #3 - vadd.u8 d0, d3, d22 - vext.8 d6, d22, d23, #6 - vadd.u8 d1, d0, d5 - vext.8 d7, d23, d23, #1 - vld1.8 {q11}, [r0], r12 - vst1.32 {d0[0]}, [r1,:32], r2 - vadd.u8 d2, d1, d6 - vst1.32 {d1[0]}, [r1], r2 - vadd.u8 d3, d2, d7 - vst1.32 {d2[0]}, [r1], r2 - vst1.32 {d3[0]}, [r1], r2 - subs r3, r3, #12 - bgt 1b - - bx lr -endfunc - -func png_read_filter_row_up_neon, export=1 - ldr r3, [r0, #4] @ rowbytes -1: - vld1.8 {q0}, [r1,:128] - vld1.8 {q1}, [r2,:128]! - vadd.u8 q0, q0, q1 - vst1.8 {q0}, [r1,:128]! - subs r3, r3, #16 - bgt 1b - - bx lr -endfunc - -func png_read_filter_row_avg4_neon, export=1 - ldr r12, [r0, #4] @ rowbytes - vmov.i8 d3, #0 -1: - vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] - vld4.32 {d16[],d17[],d18[],d19[]},[r2,:128]! - vhadd.u8 d0, d3, d16 - vadd.u8 d0, d0, d4 - vhadd.u8 d1, d0, d17 - vadd.u8 d1, d1, d5 - vhadd.u8 d2, d1, d18 - vadd.u8 d2, d2, d6 - vhadd.u8 d3, d2, d19 - vadd.u8 d3, d3, d7 - vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! - subs r12, r12, #16 - bgt 1b - - bx lr -endfunc - -func png_read_filter_row_avg3_neon, export=1 - push {r4,lr} - ldr r12, [r0, #4] @ rowbytes - vmov.i8 d3, #0 - mov r0, r1 - mov r4, #3 - mov lr, #12 - vld1.8 {q11}, [r0], lr -1: - vld1.8 {q10}, [r2], lr - vext.8 d5, d22, d23, #3 - vhadd.u8 d0, d3, d20 - vext.8 d17, d20, d21, #3 - vadd.u8 d0, d0, d22 - vext.8 d6, d22, d23, #6 - vhadd.u8 d1, d0, d17 - vext.8 d18, d20, d21, #6 - vadd.u8 d1, d1, d5 - vext.8 d7, d23, d23, #1 - vld1.8 {q11}, [r0], lr - vst1.32 {d0[0]}, [r1,:32], r4 - vhadd.u8 d2, d1, d18 - vst1.32 {d1[0]}, [r1], r4 - vext.8 d19, d21, d21, #1 - vadd.u8 d2, d2, d6 - vhadd.u8 d3, d2, d19 - vst1.32 {d2[0]}, [r1], r4 - vadd.u8 d3, d3, d7 - vst1.32 {d3[0]}, [r1], r4 - subs r12, r12, #12 - bgt 1b - - pop {r4,pc} -endfunc - -.macro paeth rx, ra, rb, rc - vaddl.u8 q12, \ra, \rb @ a + b - vaddl.u8 q15, \rc, \rc @ 2*c - vabdl.u8 q13, \rb, \rc @ pa - vabdl.u8 q14, \ra, \rc @ pb - vabd.u16 q15, q12, q15 @ pc - vcle.u16 q12, q13, q14 @ pa <= pb - vcle.u16 q13, q13, q15 @ pa <= pc - vcle.u16 q14, q14, q15 @ pb <= pc - vand q12, q12, q13 @ pa <= pb && pa <= pc - vmovn.u16 d28, q14 - vmovn.u16 \rx, q12 - vbsl d28, \rb, \rc - vbsl \rx, \ra, d28 -.endm - -func png_read_filter_row_paeth4_neon, export=1 - ldr r12, [r0, #4] @ rowbytes - vmov.i8 d3, #0 - vmov.i8 d20, #0 -1: - vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] - vld4.32 {d16[],d17[],d18[],d19[]},[r2,:128]! - paeth d0, d3, d16, d20 - vadd.u8 d0, d0, d4 - paeth d1, d0, d17, d16 - vadd.u8 d1, d1, d5 - paeth d2, d1, d18, d17 - vadd.u8 d2, d2, d6 - paeth d3, d2, d19, d18 - vmov d20, d19 - vadd.u8 d3, d3, d7 - vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! - subs r12, r12, #16 - bgt 1b - - bx lr -endfunc - -func png_read_filter_row_paeth3_neon, export=1 - push {r4,lr} - ldr r12, [r0, #4] @ rowbytes - vmov.i8 d3, #0 - vmov.i8 d4, #0 - mov r0, r1 - mov r4, #3 - mov lr, #12 - vld1.8 {q11}, [r0], lr -1: - vld1.8 {q10}, [r2], lr - paeth d0, d3, d20, d4 - vext.8 d5, d22, d23, #3 - vadd.u8 d0, d0, d22 - vext.8 d17, d20, d21, #3 - paeth d1, d0, d17, d20 - vst1.32 {d0[0]}, [r1,:32], r4 - vext.8 d6, d22, d23, #6 - vadd.u8 d1, d1, d5 - vext.8 d18, d20, d21, #6 - paeth d2, d1, d18, d17 - vext.8 d7, d23, d23, #1 - vld1.8 {q11}, [r0], lr - vst1.32 {d1[0]}, [r1], r4 - vadd.u8 d2, d2, d6 - vext.8 d19, d21, d21, #1 - paeth d3, d2, d19, d18 - vst1.32 {d2[0]}, [r1], r4 - vmov d4, d19 - vadd.u8 d3, d3, d7 - vst1.32 {d3[0]}, [r1], r4 - subs r12, r12, #12 - bgt 1b - - pop {r4,pc} -endfunc -#endif /* PNG_ARM_NEON_OPT > 0 */ -#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */ -#endif /* READ */ diff --git a/third_party/libpng/arm/filter_neon_intrinsics.c b/third_party/libpng/arm/filter_neon_intrinsics.c deleted file mode 100644 index 22923b4b4f..0000000000 --- a/third_party/libpng/arm/filter_neon_intrinsics.c +++ /dev/null @@ -1,387 +0,0 @@ - -/* filter_neon_intrinsics.c - NEON optimised filter functions - * - * Copyright (c) 2014,2016 Glenn Randers-Pehrson - * Written by James Yu <james.yu at linaro.org>, October 2013. - * Based on filter_neon.S, written by Mans Rullgard, 2011. - * - * Last changed in libpng 1.6.22 [(PENDING RELEASE)] - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "../pngpriv.h" - -#ifdef PNG_READ_SUPPORTED - -/* This code requires -mfpu=neon on the command line: */ -#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */ - -#include <arm_neon.h> - -/* libpng row pointers are not necessarily aligned to any particular boundary, - * however this code will only work with appropriate alignment. arm/arm_init.c - * checks for this (and will not compile unless it is done). This code uses - * variants of png_aligncast to avoid compiler warnings. - */ -#define png_ptr(type,pointer) png_aligncast(type *,pointer) -#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer) - -/* The following relies on a variable 'temp_pointer' being declared with type - * 'type'. This is written this way just to hide the GCC strict aliasing - * warning; note that the code is safe because there never is an alias between - * the input and output pointers. - */ -#define png_ldr(type,pointer)\ - (temp_pointer = png_ptr(type,pointer), *temp_pointer) - -#if PNG_ARM_NEON_OPT > 0 - -void -png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_bytep rp = row; - png_bytep rp_stop = row + row_info->rowbytes; - png_const_bytep pp = prev_row; - - png_debug(1, "in png_read_filter_row_up_neon"); - - for (; rp < rp_stop; rp += 16, pp += 16) - { - uint8x16_t qrp, qpp; - - qrp = vld1q_u8(rp); - qpp = vld1q_u8(pp); - qrp = vaddq_u8(qrp, qpp); - vst1q_u8(rp, qrp); - } -} - -void -png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_bytep rp = row; - png_bytep rp_stop = row + row_info->rowbytes; - - uint8x16_t vtmp = vld1q_u8(rp); - uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp); - uint8x8x2_t vrp = *vrpt; - - uint8x8x4_t vdest; - vdest.val[3] = vdup_n_u8(0); - - png_debug(1, "in png_read_filter_row_sub3_neon"); - - for (; rp < rp_stop;) - { - uint8x8_t vtmp1, vtmp2; - uint32x2_t *temp_pointer; - - vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); - vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]); - vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6); - vdest.val[1] = vadd_u8(vdest.val[0], vtmp1); - - vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); - vdest.val[2] = vadd_u8(vdest.val[1], vtmp2); - vdest.val[3] = vadd_u8(vdest.val[2], vtmp1); - - vtmp = vld1q_u8(rp + 12); - vrpt = png_ptr(uint8x8x2_t, &vtmp); - vrp = *vrpt; - - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); - rp += 3; - } - - PNG_UNUSED(prev_row) -} - -void -png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_bytep rp = row; - png_bytep rp_stop = row + row_info->rowbytes; - - uint8x8x4_t vdest; - vdest.val[3] = vdup_n_u8(0); - - png_debug(1, "in png_read_filter_row_sub4_neon"); - - for (; rp < rp_stop; rp += 16) - { - uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp)); - uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp); - uint8x8x4_t vrp = *vrpt; - uint32x2x4_t *temp_pointer; - - vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]); - vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]); - vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]); - vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]); - vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0); - } - - PNG_UNUSED(prev_row) -} - -void -png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_bytep rp = row; - png_const_bytep pp = prev_row; - png_bytep rp_stop = row + row_info->rowbytes; - - uint8x16_t vtmp; - uint8x8x2_t *vrpt; - uint8x8x2_t vrp; - uint8x8x4_t vdest; - vdest.val[3] = vdup_n_u8(0); - - vtmp = vld1q_u8(rp); - vrpt = png_ptr(uint8x8x2_t,&vtmp); - vrp = *vrpt; - - png_debug(1, "in png_read_filter_row_avg3_neon"); - - for (; rp < rp_stop; pp += 12) - { - uint8x8_t vtmp1, vtmp2, vtmp3; - - uint8x8x2_t *vppt; - uint8x8x2_t vpp; - - uint32x2_t *temp_pointer; - - vtmp = vld1q_u8(pp); - vppt = png_ptr(uint8x8x2_t,&vtmp); - vpp = *vppt; - - vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); - vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]); - vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); - - vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3); - vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6); - vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2); - vdest.val[1] = vadd_u8(vdest.val[1], vtmp1); - - vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6); - vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); - - vtmp = vld1q_u8(rp + 12); - vrpt = png_ptr(uint8x8x2_t,&vtmp); - vrp = *vrpt; - - vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2); - vdest.val[2] = vadd_u8(vdest.val[2], vtmp3); - - vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1); - - vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2); - vdest.val[3] = vadd_u8(vdest.val[3], vtmp1); - - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); - rp += 3; - } -} - -void -png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_bytep rp = row; - png_bytep rp_stop = row + row_info->rowbytes; - png_const_bytep pp = prev_row; - - uint8x8x4_t vdest; - vdest.val[3] = vdup_n_u8(0); - - png_debug(1, "in png_read_filter_row_avg4_neon"); - - for (; rp < rp_stop; rp += 16, pp += 16) - { - uint32x2x4_t vtmp; - uint8x8x4_t *vrpt, *vppt; - uint8x8x4_t vrp, vpp; - uint32x2x4_t *temp_pointer; - - vtmp = vld4_u32(png_ptr(uint32_t,rp)); - vrpt = png_ptr(uint8x8x4_t,&vtmp); - vrp = *vrpt; - vtmp = vld4_u32(png_ptrc(uint32_t,pp)); - vppt = png_ptr(uint8x8x4_t,&vtmp); - vpp = *vppt; - - vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]); - vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); - vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]); - vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]); - vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]); - vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]); - vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]); - vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]); - - vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0); - } -} - -static uint8x8_t -paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c) -{ - uint8x8_t d, e; - uint16x8_t p1, pa, pb, pc; - - p1 = vaddl_u8(a, b); /* a + b */ - pc = vaddl_u8(c, c); /* c * 2 */ - pa = vabdl_u8(b, c); /* pa */ - pb = vabdl_u8(a, c); /* pb */ - pc = vabdq_u16(p1, pc); /* pc */ - - p1 = vcleq_u16(pa, pb); /* pa <= pb */ - pa = vcleq_u16(pa, pc); /* pa <= pc */ - pb = vcleq_u16(pb, pc); /* pb <= pc */ - - p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */ - - d = vmovn_u16(pb); - e = vmovn_u16(p1); - - d = vbsl_u8(d, b, c); - e = vbsl_u8(e, a, d); - - return e; -} - -void -png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_bytep rp = row; - png_const_bytep pp = prev_row; - png_bytep rp_stop = row + row_info->rowbytes; - - uint8x16_t vtmp; - uint8x8x2_t *vrpt; - uint8x8x2_t vrp; - uint8x8_t vlast = vdup_n_u8(0); - uint8x8x4_t vdest; - vdest.val[3] = vdup_n_u8(0); - - vtmp = vld1q_u8(rp); - vrpt = png_ptr(uint8x8x2_t,&vtmp); - vrp = *vrpt; - - png_debug(1, "in png_read_filter_row_paeth3_neon"); - - for (; rp < rp_stop; pp += 12) - { - uint8x8x2_t *vppt; - uint8x8x2_t vpp; - uint8x8_t vtmp1, vtmp2, vtmp3; - uint32x2_t *temp_pointer; - - vtmp = vld1q_u8(pp); - vppt = png_ptr(uint8x8x2_t,&vtmp); - vpp = *vppt; - - vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast); - vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); - - vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); - vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3); - vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]); - vdest.val[1] = vadd_u8(vdest.val[1], vtmp1); - - vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6); - vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6); - vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2); - vdest.val[2] = vadd_u8(vdest.val[2], vtmp1); - - vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); - vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1); - - vtmp = vld1q_u8(rp + 12); - vrpt = png_ptr(uint8x8x2_t,&vtmp); - vrp = *vrpt; - - vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3); - vdest.val[3] = vadd_u8(vdest.val[3], vtmp1); - - vlast = vtmp2; - - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); - rp += 3; - vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); - rp += 3; - } -} - -void -png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_bytep rp = row; - png_bytep rp_stop = row + row_info->rowbytes; - png_const_bytep pp = prev_row; - - uint8x8_t vlast = vdup_n_u8(0); - uint8x8x4_t vdest; - vdest.val[3] = vdup_n_u8(0); - - png_debug(1, "in png_read_filter_row_paeth4_neon"); - - for (; rp < rp_stop; rp += 16, pp += 16) - { - uint32x2x4_t vtmp; - uint8x8x4_t *vrpt, *vppt; - uint8x8x4_t vrp, vpp; - uint32x2x4_t *temp_pointer; - - vtmp = vld4_u32(png_ptr(uint32_t,rp)); - vrpt = png_ptr(uint8x8x4_t,&vtmp); - vrp = *vrpt; - vtmp = vld4_u32(png_ptrc(uint32_t,pp)); - vppt = png_ptr(uint8x8x4_t,&vtmp); - vpp = *vppt; - - vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast); - vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); - vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]); - vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]); - vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]); - vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]); - vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]); - vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]); - - vlast = vpp.val[3]; - - vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0); - } -} - -#endif /* PNG_ARM_NEON_OPT > 0 */ -#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */ -#endif /* READ */ diff --git a/third_party/libpng/contrib/README.txt b/third_party/libpng/contrib/README.txt deleted file mode 100644 index 97963c6d54..0000000000 --- a/third_party/libpng/contrib/README.txt +++ /dev/null @@ -1,5 +0,0 @@ - -This "contrib" directory contains contributions which are not necessarily under -the libpng license, although all are open source. They are not part of -libpng proper and are not used for building the library, although some are used -for testing the library via "make check". diff --git a/third_party/libpng/contrib/intel/INSTALL b/third_party/libpng/contrib/intel/INSTALL deleted file mode 100644 index acfa9daafe..0000000000 --- a/third_party/libpng/contrib/intel/INSTALL +++ /dev/null @@ -1,176 +0,0 @@ -Enabling SSE support - -Copyright (c) 2016 Google, Inc. -Written by Mike Klein, Matt Sarett - -This INSTALL file written by Glenn Randers-Pehrson, 2016. - -If you have moved intel_init.c and filter_sse2_intrinsics.c to a different -directory, be sure to update the '#include "../../pngpriv.h"' line in both -files if necessary to point to the correct relative location of pngpriv.h -with respect to the new location of those files. - -To enable SSE support in libpng, follow the instructions in I, II, or III, -below: - -I. Using patched "configure" scripts: - -First, apply intel_sse.patch in your build directory. - - patch -i contrib/intel/intel_sse.patch -p1 - -Then, if you are not building in a new GIT clone, e.g., in a tar -distribution, remove any existing pre-built configure scripts: - - ./configure --enable-maintainer-mode - make maintainer-clean - ./autogen.sh --maintainer --clean - -Finally, configure libpng with -DPNG_INTEL_SSE in CPPFLAGS: - - ./autogen.sh --maintainer - CPPFLAGS="-DPNG_INTEL_SSE" ./configure [options] - make CPPFLAGS="-DPNG_INTEL_SSE" [options] - make - -II. Using a custom makefile: - -If you are using a custom makefile makefile, you will have to update it -manually to include contrib/intel/*.o in the dependencies, and to define -PNG_INTEL_SSE. - -III. Using manually updated "configure" scripts: - -If you prefer, manually edit pngpriv.h, configure.ac, and Makefile.am, -following the instructions below, then follow the instructions in -section II of INSTALL in the main libpng directory, then configure libpng -with -DPNG_INTEL_SSE in CPPFLAGS. - -1. Insert the following lines above the copyright line near the top of -configure.ac: - ------------------cut---------------- -# Copyright (c) 2016 Google, Inc. -# Written by Mike Klein and Matt Sarett -# Derived from the ARM supporting code in libpng/configure.ac, which was ------------------cut---------------- - -2. Add the following code to configure.ac under HOST SPECIFIC OPTIONS -directly beneath the section for ARM: - ------------------cut---------------- -# INTEL -# ===== -# -# INTEL SSE (SIMD) support. - -AC_ARG_ENABLE([intel-sse], - AS_HELP_STRING([[[--enable-intel-sse]]], - [Enable Intel SSE optimizations: =no/off, yes/on:] - [no/off: disable the optimizations;] - [yes/on: enable the optimizations.] - [If not specified: determined by the compiler.]), - [case "$enableval" in - no|off) - # disable the default enabling: - AC_DEFINE([PNG_INTEL_SSE_OPT], [0], - [Disable Intel SSE optimizations]) - # Prevent inclusion of the assembler files below: - enable_intel_sse=no;; - yes|on) - AC_DEFINE([PNG_INTEL_SSE_OPT], [1], - [Enable Intel SSE optimizations]);; - *) - AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}: invalid value]) - esac]) - -# Add Intel specific files to all builds where the host_cpu is Intel ('x86*') -# or where Intel optimizations were explicitly requested (this allows a -# fallback if a future host CPU does not match 'x86*') -AM_CONDITIONAL([PNG_INTEL_SSE], - [test "$enable_intel_sse" != 'no' && - case "$host_cpu" in - i?86|x86_64) :;; - *) test "$enable_intel_sse" != '';; - esac]) ------------------cut---------------- - -3. Insert the following lines above the copyright line near the top of -Makefile.am: - ------------------cut---------------- -# Copyright (c) 2016 Google, Inc. -# Written by Mike Klein and Matt Sarett -# Derived from the ARM supporting code in libpng/configure.ac, which was ------------------cut---------------- - -4. Add the following code to Makefile.am under HOST SPECIFIC OPTIONS -directly beneath the "if PNG_ARM_NEON ... endif" statement: - ------------------cut---------------- -if PNG_INTEL_SSE -libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += contrib/intel/intel_init.c\ - contrib/intel/filter_sse2_intrinsics.c -endif ------------------cut---------------- - -5. Add the following lines to pngpriv.h, following the PNG_ARM_NEON_OPT -code: - ------------------cut---------------- -#ifndef PNG_INTEL_SSE_OPT -# ifdef PNG_INTEL_SSE - /* Only check for SSE if the build configuration has been modified to - * enable SSE optimizations. This means that these optimizations will - * be off by default. See contrib/intel for more details. - */ -# if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \ - defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ - (defined(_M_IX86_FP) && _M_IX86_FP >= 2) -# define PNG_INTEL_SSE_OPT 1 -# endif -# endif -#endif - -#if PNG_INTEL_SSE_OPT > 0 -# ifndef PNG_INTEL_SSE_IMPLEMENTATION -# if defined(__SSE4_1__) || defined(__AVX__) - /* We are not actually using AVX, but checking for AVX is the best - way we can detect SSE4.1 and SSSE3 on MSVC. - */ -# define PNG_INTEL_SSE_IMPLEMENTATION 3 -# elif defined(__SSSE3__) -# define PNG_INTEL_SSE_IMPLEMENTATION 2 -# elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ - (defined(_M_IX86_FP) && _M_IX86_FP >= 2) -# define PNG_INTEL_SSE_IMPLEMENTATION 1 -# else -# define PNG_INTEL_SSE_IMPLEMENTATION 0 -# endif -# endif - -# if PNG_INTEL_SSE_IMPLEMENTATION > 0 -# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2 -# endif -#endif - ------------------cut---------------- - -5. Add the following lines to pngpriv.h, following the prototype for -png_read_filter_row_paeth4_neon: - ------------------cut---------------- -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); - ------------------cut---------------- diff --git a/third_party/libpng/contrib/intel/filter_sse2_intrinsics.c b/third_party/libpng/contrib/intel/filter_sse2_intrinsics.c deleted file mode 100644 index 92dcd7e4ac..0000000000 --- a/third_party/libpng/contrib/intel/filter_sse2_intrinsics.c +++ /dev/null @@ -1,379 +0,0 @@ - -/* filter_sse2_intrinsics.c - SSE2 optimized filter functions - * - * Copyright (c) 2016 Google, Inc. - * Written by Mike Klein and Matt Sarett - * Derived from arm/filter_neon_intrinsics.c, which was - * Copyright (c) 2014,2016 Glenn Randers-Pehrson - * - * Last changed in libpng 1.6.22 [(PENDING RELEASE)] - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "../../pngpriv.h" - -#ifdef PNG_READ_SUPPORTED - -#if PNG_INTEL_SSE_IMPLEMENTATION > 0 - -#include <immintrin.h> - -/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d). - * They're positioned like this: - * prev: c b - * row: a d - * The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be - * whichever of a, b, or c is closest to p=a+b-c. - */ - -static __m128i load4(const void* p) { - return _mm_cvtsi32_si128(*(const int*)p); -} - -static void store4(void* p, __m128i v) { - *(int*)p = _mm_cvtsi128_si32(v); -} - -static __m128i load3(const void* p) { - /* We'll load 2 bytes, then 1 byte, - * then mask them together, and finally load into SSE. - */ - const png_uint_16* p01 = p; - const png_byte* p2 = (const png_byte*)(p01+1); - - png_uint_32 v012 = (png_uint_32)(*p01) - | (png_uint_32)(*p2) << 16; - return load4(&v012); -} - -static void store3(void* p, __m128i v) { - /* We'll pull from SSE as a 32-bit int, then write - * its bottom two bytes, then its third byte. - */ - png_uint_32 v012; - store4(&v012, v); - - png_uint_16* p01 = p; - png_byte* p2 = (png_byte*)(p01+1); - *p01 = v012; - *p2 = v012 >> 16; -} - -void png_read_filter_row_sub3_sse2(png_row_infop row_info, png_bytep row, - png_const_bytep prev) -{ - /* The Sub filter predicts each pixel as the previous pixel, a. - * There is no pixel to the left of the first pixel. It's encoded directly. - * That works with our main loop if we just say that left pixel was zero. - */ - png_debug(1, "in png_read_filter_row_sub3_sse2"); - __m128i a, d = _mm_setzero_si128(); - - int rb = row_info->rowbytes; - while (rb >= 4) { - a = d; d = load4(row); - d = _mm_add_epi8(d, a); - store3(row, d); - - row += 3; - rb -= 3; - } - if (rb > 0) { - a = d; d = load3(row); - d = _mm_add_epi8(d, a); - store3(row, d); - - row += 3; - rb -= 3; - } -} - -void png_read_filter_row_sub4_sse2(png_row_infop row_info, png_bytep row, - png_const_bytep prev) -{ - /* The Sub filter predicts each pixel as the previous pixel, a. - * There is no pixel to the left of the first pixel. It's encoded directly. - * That works with our main loop if we just say that left pixel was zero. - */ - png_debug(1, "in png_read_filter_row_sub4_sse2"); - __m128i a, d = _mm_setzero_si128(); - - int rb = row_info->rowbytes; - while (rb > 0) { - a = d; d = load4(row); - d = _mm_add_epi8(d, a); - store4(row, d); - - row += 4; - rb -= 4; - } -} - -void png_read_filter_row_avg3_sse2(png_row_infop row_info, png_bytep row, - png_const_bytep prev) -{ - /* The Avg filter predicts each pixel as the (truncated) average of a and b. - * There's no pixel to the left of the first pixel. Luckily, it's - * predicted to be half of the pixel above it. So again, this works - * perfectly with our loop if we make sure a starts at zero. - */ - png_debug(1, "in png_read_filter_row_avg3_sse2"); - const __m128i zero = _mm_setzero_si128(); - __m128i b; - __m128i a, d = zero; - - int rb = row_info->rowbytes; - while (rb >= 4) { - b = load4(prev); - a = d; d = load4(row ); - - /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ - __m128i avg = _mm_avg_epu8(a,b); - /* ...but we can fix it up by subtracting off 1 if it rounded up. */ - avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), - _mm_set1_epi8(1))); - d = _mm_add_epi8(d, avg); - store3(row, d); - - prev += 3; - row += 3; - rb -= 3; - } - if (rb > 0) { - b = load3(prev); - a = d; d = load3(row ); - - /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ - __m128i avg = _mm_avg_epu8(a,b); - /* ...but we can fix it up by subtracting off 1 if it rounded up. */ - avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), - _mm_set1_epi8(1))); - - d = _mm_add_epi8(d, avg); - store3(row, d); - - prev += 3; - row += 3; - rb -= 3; - } -} - -void png_read_filter_row_avg4_sse2(png_row_infop row_info, png_bytep row, - png_const_bytep prev) -{ - /* The Avg filter predicts each pixel as the (truncated) average of a and b. - * There's no pixel to the left of the first pixel. Luckily, it's - * predicted to be half of the pixel above it. So again, this works - * perfectly with our loop if we make sure a starts at zero. - */ - png_debug(1, "in png_read_filter_row_avg4_sse2"); - const __m128i zero = _mm_setzero_si128(); - __m128i b; - __m128i a, d = zero; - - int rb = row_info->rowbytes; - while (rb > 0) { - b = load4(prev); - a = d; d = load4(row ); - - /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ - __m128i avg = _mm_avg_epu8(a,b); - /* ...but we can fix it up by subtracting off 1 if it rounded up. */ - avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), - _mm_set1_epi8(1))); - - d = _mm_add_epi8(d, avg); - store4(row, d); - - prev += 4; - row += 4; - rb -= 4; - } -} - -/* Returns |x| for 16-bit lanes. */ -static __m128i abs_i16(__m128i x) { -#if PNG_INTEL_SSE_IMPLEMENTATION >= 2 - return _mm_abs_epi16(x); -#else - /* Read this all as, return x<0 ? -x : x. - * To negate two's complement, you flip all the bits then add 1. - */ - __m128i is_negative = _mm_cmplt_epi16(x, _mm_setzero_si128()); - - /* Flip negative lanes. */ - x = _mm_xor_si128(x, is_negative); - - /* +1 to negative lanes, else +0. */ - x = _mm_add_epi16(x, _mm_srli_epi16(is_negative, 15)); - return x; -#endif -} - -/* Bytewise c ? t : e. */ -static __m128i if_then_else(__m128i c, __m128i t, __m128i e) { -#if PNG_INTEL_SSE_IMPLEMENTATION >= 3 - return _mm_blendv_epi8(e,t,c); -#else - return _mm_or_si128(_mm_and_si128(c, t), _mm_andnot_si128(c, e)); -#endif -} - -void png_read_filter_row_paeth3_sse2(png_row_infop row_info, png_bytep row, - png_const_bytep prev) -{ - /* Paeth tries to predict pixel d using the pixel to the left of it, a, - * and two pixels from the previous row, b and c: - * prev: c b - * row: a d - * The Paeth function predicts d to be whichever of a, b, or c is nearest to - * p=a+b-c. - * - * The first pixel has no left context, and so uses an Up filter, p = b. - * This works naturally with our main loop's p = a+b-c if we force a and c - * to zero. - * Here we zero b and d, which become c and a respectively at the start of - * the loop. - */ - png_debug(1, "in png_read_filter_row_paeth3_sse2"); - const __m128i zero = _mm_setzero_si128(); - __m128i c, b = zero, - a, d = zero; - - int rb = row_info->rowbytes; - while (rb >= 4) { - /* It's easiest to do this math (particularly, deal with pc) with 16-bit - * intermediates. - */ - c = b; b = _mm_unpacklo_epi8(load4(prev), zero); - a = d; d = _mm_unpacklo_epi8(load4(row ), zero); - - /* (p-a) == (a+b-c - a) == (b-c) */ - __m128i pa = _mm_sub_epi16(b,c); - - /* (p-b) == (a+b-c - b) == (a-c) */ - __m128i pb = _mm_sub_epi16(a,c); - - /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ - __m128i pc = _mm_add_epi16(pa,pb); - - pa = abs_i16(pa); /* |p-a| */ - pb = abs_i16(pb); /* |p-b| */ - pc = abs_i16(pc); /* |p-c| */ - - __m128i smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); - - /* Paeth breaks ties favoring a over b over c. */ - __m128i nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, - if_then_else(_mm_cmpeq_epi16(smallest, pb), b, - c)); - - /* Note `_epi8`: we need addition to wrap modulo 255. */ - d = _mm_add_epi8(d, nearest); - store3(row, _mm_packus_epi16(d,d)); - - prev += 3; - row += 3; - rb -= 3; - } - if (rb > 0) { - /* It's easiest to do this math (particularly, deal with pc) with 16-bit - * intermediates. - */ - c = b; b = _mm_unpacklo_epi8(load3(prev), zero); - a = d; d = _mm_unpacklo_epi8(load3(row ), zero); - - /* (p-a) == (a+b-c - a) == (b-c) */ - __m128i pa = _mm_sub_epi16(b,c); - - /* (p-b) == (a+b-c - b) == (a-c) */ - __m128i pb = _mm_sub_epi16(a,c); - - /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ - __m128i pc = _mm_add_epi16(pa,pb); - - pa = abs_i16(pa); /* |p-a| */ - pb = abs_i16(pb); /* |p-b| */ - pc = abs_i16(pc); /* |p-c| */ - - __m128i smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); - - /* Paeth breaks ties favoring a over b over c. */ - __m128i nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, - if_then_else(_mm_cmpeq_epi16(smallest, pb), b, - c)); - - /* Note `_epi8`: we need addition to wrap modulo 255. */ - d = _mm_add_epi8(d, nearest); - store3(row, _mm_packus_epi16(d,d)); - - prev += 3; - row += 3; - rb -= 3; - } -} - -void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row, - png_const_bytep prev) -{ - /* Paeth tries to predict pixel d using the pixel to the left of it, a, - * and two pixels from the previous row, b and c: - * prev: c b - * row: a d - * The Paeth function predicts d to be whichever of a, b, or c is nearest to - * p=a+b-c. - * - * The first pixel has no left context, and so uses an Up filter, p = b. - * This works naturally with our main loop's p = a+b-c if we force a and c - * to zero. - * Here we zero b and d, which become c and a respectively at the start of - * the loop. - */ - png_debug(1, "in png_read_filter_row_paeth4_sse2"); - const __m128i zero = _mm_setzero_si128(); - __m128i c, b = zero, - a, d = zero; - - int rb = row_info->rowbytes; - while (rb > 0) { - /* It's easiest to do this math (particularly, deal with pc) with 16-bit - * intermediates. - */ - c = b; b = _mm_unpacklo_epi8(load4(prev), zero); - a = d; d = _mm_unpacklo_epi8(load4(row ), zero); - - /* (p-a) == (a+b-c - a) == (b-c) */ - __m128i pa = _mm_sub_epi16(b,c); - - /* (p-b) == (a+b-c - b) == (a-c) */ - __m128i pb = _mm_sub_epi16(a,c); - - /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ - __m128i pc = _mm_add_epi16(pa,pb); - - pa = abs_i16(pa); /* |p-a| */ - pb = abs_i16(pb); /* |p-b| */ - pc = abs_i16(pc); /* |p-c| */ - - __m128i smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); - - /* Paeth breaks ties favoring a over b over c. */ - __m128i nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, - if_then_else(_mm_cmpeq_epi16(smallest, pb), b, - c)); - - /* Note `_epi8`: we need addition to wrap modulo 255. */ - d = _mm_add_epi8(d, nearest); - store4(row, _mm_packus_epi16(d,d)); - - prev += 4; - row += 4; - rb -= 4; - } -} - -#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */ -#endif /* READ */ diff --git a/third_party/libpng/contrib/intel/intel_init.c b/third_party/libpng/contrib/intel/intel_init.c deleted file mode 100644 index 357e147b9d..0000000000 --- a/third_party/libpng/contrib/intel/intel_init.c +++ /dev/null @@ -1,54 +0,0 @@ - -/* intel_init.c - SSE2 optimized filter functions - * - * Copyright (c) 2016 Google, Inc. - * Written by Mike Klein and Matt Sarett - * Derived from arm/arm_init.c, which was - * Copyright (c) 2014,2016 Glenn Randers-Pehrson - * - * Last changed in libpng 1.6.22 [(PENDING RELEASE)] - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "../../pngpriv.h" - -#ifdef PNG_READ_SUPPORTED -#if PNG_INTEL_SSE_IMPLEMENTATION > 0 - -void -png_init_filter_functions_sse2(png_structp pp, unsigned int bpp) -{ - /* The techniques used to implement each of these filters in SSE operate on - * one pixel at a time. - * So they generally speed up 3bpp images about 3x, 4bpp images about 4x. - * They can scale up to 6 and 8 bpp images and down to 2 bpp images, - * but they'd not likely have any benefit for 1bpp images. - * Most of these can be implemented using only MMX and 64-bit registers, - * but they end up a bit slower than using the equally-ubiquitous SSE2. - */ - png_debug(1, "in png_init_filter_functions_sse2"); - if (bpp == 3) - { - pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2; - pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2; - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth3_sse2; - } - else if (bpp == 4) - { - pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2; - pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2; - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth4_sse2; - } - - /* No need optimize PNG_FILTER_VALUE_UP. The compiler should - * autovectorize. - */ -} - -#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */ -#endif /* PNG_READ_SUPPORTED */ diff --git a/third_party/libpng/contrib/intel/intel_sse.patch b/third_party/libpng/contrib/intel/intel_sse.patch deleted file mode 100644 index 174f5895c7..0000000000 --- a/third_party/libpng/contrib/intel/intel_sse.patch +++ /dev/null @@ -1,192 +0,0 @@ -diff --git a/configure.ac b/configure.ac ---- a/configure.ac 2016-04-27 22:33:47.805069558 -0500 -+++ b/configure.ac 2016-04-27 22:33:47.829012469 -0500 -@@ -1,10 +1,13 @@ - # configure.ac - -+# Copyright (c) 2016 Google, Inc. -+# Written by Mike Klein and Matt Sarett -+# Derived from the ARM supporting code in libpng/configure.ac, which was - # Copyright (c) 2004-2015 Glenn Randers-Pehrson - # Last changed in libpng 1.6.22 [(PENDING RELEASE)] - - # This code is released under the libpng license. - # For conditions of distribution and use, see the disclaimer - # and license in png.h - - dnl Process this file with autoconf to produce a configure script. -@@ -335,16 +338,50 @@ AC_ARG_ENABLE([arm-neon], - - AM_CONDITIONAL([PNG_ARM_NEON], - [test "$enable_arm_neon" != 'no' && - case "$host_cpu" in - arm*|aarch64*) :;; - *) test "$enable_arm_neon" != '';; - esac]) - -+# INTEL -+# ===== -+# -+# INTEL SSE (SIMD) support. -+ -+AC_ARG_ENABLE([intel-sse], -+ AS_HELP_STRING([[[--enable-intel-sse]]], -+ [Enable Intel SSE optimizations: =no/off, yes/on:] -+ [no/off: disable the optimizations;] -+ [yes/on: enable the optimizations.] -+ [If not specified: determined by the compiler.]), -+ [case "$enableval" in -+ no|off) -+ # disable the default enabling: -+ AC_DEFINE([PNG_INTEL_SSE_OPT], [0], -+ [Disable Intel SSE optimizations]) -+ # Prevent inclusion of the assembler files below: -+ enable_intel_sse=no;; -+ yes|on) -+ AC_DEFINE([PNG_INTEL_SSE_OPT], [1], -+ [Enable Intel SSE optimizations]);; -+ *) -+ AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}: invalid value]) -+ esac]) -+ -+# Add Intel specific files to all builds where the host_cpu is Intel ('x86*') -+# or where Intel optimizations were explicitly requested (this allows a -+# fallback if a future host CPU does not match 'x86*') -+AM_CONDITIONAL([PNG_INTEL_SSE], -+ [test "$enable_intel_sse" != 'no' && -+ case "$host_cpu" in -+ i?86|x86_64) :;; -+ *) test "$enable_intel_sse" != '';; -+ esac]) - AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]]) - - # Config files, substituting as above - AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in]) - AC_CONFIG_FILES([libpng-config:libpng-config.in], - [chmod +x libpng-config]) - - AC_OUTPUT -diff --git a/Makefile.am b/Makefile.am ---- a/Makefile.am 2016-04-27 22:33:47.809928404 -0500 -+++ b/Makefile.am 2016-04-27 22:33:47.832941146 -0500 -@@ -1,10 +1,13 @@ - # Makefile.am, the source file for Makefile.in (and hence Makefile), is - # -+# Copyright (c) 2016 Google, Inc. -+# Written by Mike Klein and Matt Sarett -+# Derived from the ARM supporting code in libpng/configure.ac, which was - # Copyright (c) 2004-2016 Glenn Randers-Pehrson - # Last changed in libpng 1.6.22 [(PENDING RELEASE)] - # - # This code is released under the libpng license. - # For conditions of distribution and use, see the disclaimer - # and license in png.h - - PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ -@@ -86,16 +89,20 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SO - pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c\ - png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa - - if PNG_ARM_NEON - libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\ - arm/filter_neon.S arm/filter_neon_intrinsics.c - endif - -+if PNG_INTEL_SSE -+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += contrib/intel/intel_init.c\ -+ contrib/intel/filter_sse2_intrinsics.c -+endif - nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h - - libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \ - -version-number @PNGLIB_MAJOR@@PNGLIB_MINOR@:@PNGLIB_RELEASE@:0 - - if HAVE_LD_VERSION_SCRIPT - # Versioned symbols and restricted exports - if HAVE_SOLARIS_LD -diff --git a/pngpriv.h b/pngpriv.h ---- a/pngpriv.h 2016-04-27 22:33:47.800157005 -0500 -+++ b/pngpriv.h 2016-04-27 22:33:47.838191194 -0500 -@@ -177,16 +177,52 @@ - # endif /* !PNG_ARM_NEON_IMPLEMENTATION */ - - # ifndef PNG_ARM_NEON_IMPLEMENTATION - /* Use the intrinsics code by default. */ - # define PNG_ARM_NEON_IMPLEMENTATION 1 - # endif - #endif /* PNG_ARM_NEON_OPT > 0 */ - -+#ifndef PNG_INTEL_SSE_OPT -+# ifdef PNG_INTEL_SSE -+ /* Only check for SSE if the build configuration has been modified to -+ * enable SSE optimizations. This means that these optimizations will -+ * be off by default. See contrib/intel for more details. -+ */ -+# if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \ -+ defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ -+ (defined(_M_IX86_FP) && _M_IX86_FP >= 2) -+# define PNG_INTEL_SSE_OPT 1 -+# endif -+# endif -+#endif -+ -+#if PNG_INTEL_SSE_OPT > 0 -+# ifndef PNG_INTEL_SSE_IMPLEMENTATION -+# if defined(__SSE4_1__) || defined(__AVX__) -+ /* We are not actually using AVX, but checking for AVX is the best -+ way we can detect SSE4.1 and SSSE3 on MSVC. -+ */ -+# define PNG_INTEL_SSE_IMPLEMENTATION 3 -+# elif defined(__SSSE3__) -+# define PNG_INTEL_SSE_IMPLEMENTATION 2 -+# elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ -+ (defined(_M_IX86_FP) && _M_IX86_FP >= 2) -+# define PNG_INTEL_SSE_IMPLEMENTATION 1 -+# else -+# define PNG_INTEL_SSE_IMPLEMENTATION 0 -+# endif -+# endif -+ -+# if PNG_INTEL_SSE_IMPLEMENTATION > 0 -+# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2 -+# endif -+#endif -+ - /* Is this a build of a DLL where compilation of the object modules requires - * different preprocessor settings to those required for a simple library? If - * so PNG_BUILD_DLL must be set. - * - * If libpng is used inside a DLL but that DLL does not export the libpng APIs - * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a - * static library of libpng then link the DLL against that. - */ -@@ -1184,16 +1220,29 @@ PNG_INTERNAL_FUNCTION(void,png_read_filt - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); - PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); - PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); - PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); - -+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop -+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop -+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop -+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop -+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop -+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop -+ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -+ - /* Choose the best filter to use and filter the row data */ - PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr, - png_row_infop row_info),PNG_EMPTY); - - #ifdef PNG_SEQUENTIAL_READ_SUPPORTED - PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr, - png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY); - /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer diff --git a/third_party/libpng/example.c b/third_party/libpng/example.c deleted file mode 100644 index f8591e668a..0000000000 --- a/third_party/libpng/example.c +++ /dev/null @@ -1,1061 +0,0 @@ - -#if 0 /* in case someone actually tries to compile this */ - -/* example.c - an example of using libpng - * Last changed in libpng 1.6.15 [November 20, 2014] - * Maintained 1998-2014 Glenn Randers-Pehrson - * Maintained 1996, 1997 Andreas Dilger) - * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * To the extent possible under law, the authors have waived - * all copyright and related or neighboring rights to this file. - * This work is published from: United States. - */ - -/* This is an example of how to use libpng to read and write PNG files. - * The file libpng-manual.txt is much more verbose then this. If you have not - * read it, do so first. This was designed to be a starting point of an - * implementation. This is not officially part of libpng, is hereby placed - * in the public domain, and therefore does not require a copyright notice. - * - * This file does not currently compile, because it is missing certain - * parts, like allocating memory to hold an image. You will have to - * supply these parts to get it to compile. For an example of a minimal - * working PNG reader/writer, see pngtest.c, included in this distribution; - * see also the programs in the contrib directory. - */ - -/* The simple, but restricted, approach to reading a PNG file or data stream - * just requires two function calls, as in the following complete program. - * Writing a file just needs one function call, so long as the data has an - * appropriate layout. - * - * The following code reads PNG image data from a file and writes it, in a - * potentially new format, to a new file. While this code will compile there is - * minimal (insufficient) error checking; for a more realistic version look at - * contrib/examples/pngtopng.c - */ -#include <stddef.h> -#include <stdlib.h> -#include <string.h> -#include <stdio.h> -#include <png.h> -#include <zlib.h> - -int main(int argc, const char **argv) -{ - if (argc == 3) - { - png_image image; /* The control structure used by libpng */ - - /* Initialize the 'png_image' structure. */ - memset(&image, 0, (sizeof image)); - image.version = PNG_IMAGE_VERSION; - - /* The first argument is the file to read: */ - if (png_image_begin_read_from_file(&image, argv[1]) != 0) - { - png_bytep buffer; - - /* Set the format in which to read the PNG file; this code chooses a - * simple sRGB format with a non-associated alpha channel, adequate to - * store most images. - */ - image.format = PNG_FORMAT_RGBA; - - /* Now allocate enough memory to hold the image in this format; the - * PNG_IMAGE_SIZE macro uses the information about the image (width, - * height and format) stored in 'image'. - */ - buffer = malloc(PNG_IMAGE_SIZE(image)); - - /* If enough memory was available read the image in the desired format - * then write the result out to the new file. 'background' is not - * necessary when reading the image because the alpha channel is - * preserved; if it were to be removed, for example if we requested - * PNG_FORMAT_RGB, then either a solid background color would have to - * be supplied or the output buffer would have to be initialized to the - * actual background of the image. - * - * The fourth argument to png_image_finish_read is the 'row_stride' - - * this is the number of components allocated for the image in each - * row. It has to be at least as big as the value returned by - * PNG_IMAGE_ROW_STRIDE, but if you just allocate space for the - * default, minimum, size using PNG_IMAGE_SIZE as above you can pass - * zero. - * - * The final argument is a pointer to a buffer for the colormap; - * colormaps have exactly the same format as a row of image pixels (so - * you choose what format to make the colormap by setting - * image.format). A colormap is only returned if - * PNG_FORMAT_FLAG_COLORMAP is also set in image.format, so in this - * case NULL is passed as the final argument. If you do want to force - * all images into an index/color-mapped format then you can use: - * - * PNG_IMAGE_COLORMAP_SIZE(image) - * - * to find the maximum size of the colormap in bytes. - */ - if (buffer != NULL && - png_image_finish_read(&image, NULL/*background*/, buffer, - 0/*row_stride*/, NULL/*colormap*/) != 0) - { - /* Now write the image out to the second argument. In the write - * call 'convert_to_8bit' allows 16-bit data to be squashed down to - * 8 bits; this isn't necessary here because the original read was - * to the 8-bit format. - */ - if (png_image_write_to_file(&image, argv[2], 0/*convert_to_8bit*/, - buffer, 0/*row_stride*/, NULL/*colormap*/) != 0) - { - /* The image has been written successfully. */ - exit(0); - } - } - - else - { - /* Calling png_free_image is optional unless the simplified API was - * not run to completion. In this case if there wasn't enough - * memory for 'buffer' we didn't complete the read, so we must free - * the image: - */ - if (buffer == NULL) - png_free_image(&image); - - else - free(buffer); - } - - /* Something went wrong reading or writing the image. libpng stores a - * textual message in the 'png_image' structure: - */ - fprintf(stderr, "pngtopng: error: %s\n", image.message); - exit (1); - } - - fprintf(stderr, "pngtopng: usage: pngtopng input-file output-file\n"); - exit(1); -} - -/* That's it ;-) Of course you probably want to do more with PNG files than - * just converting them all to 32-bit RGBA PNG files; you can do that between - * the call to png_image_finish_read and png_image_write_to_file. You can also - * ask for the image data to be presented in a number of different formats. You - * do this by simply changing the 'format' parameter set before allocating the - * buffer. - * - * The format parameter consists of five flags that define various aspects of - * the image, you can simply add these together to get the format or you can use - * one of the predefined macros from png.h (as above): - * - * PNG_FORMAT_FLAG_COLOR: if set the image will have three color components per - * pixel (red, green and blue), if not set the image will just have one - * luminance (grayscale) component. - * - * PNG_FORMAT_FLAG_ALPHA: if set each pixel in the image will have an additional - * alpha value; a linear value that describes the degree the image pixel - * covers (overwrites) the contents of the existing pixel on the display. - * - * PNG_FORMAT_FLAG_LINEAR: if set the components of each pixel will be returned - * as a series of 16-bit linear values, if not set the components will be - * returned as a series of 8-bit values encoded according to the 'sRGB' - * standard. The 8-bit format is the normal format for images intended for - * direct display, because almost all display devices do the inverse of the - * sRGB transformation to the data they receive. The 16-bit format is more - * common for scientific data and image data that must be further processed; - * because it is linear simple math can be done on the component values. - * Regardless of the setting of this flag the alpha channel is always linear, - * although it will be 8 bits or 16 bits wide as specified by the flag. - * - * PNG_FORMAT_FLAG_BGR: if set the components of a color pixel will be returned - * in the order blue, then green, then red. If not set the pixel components - * are in the order red, then green, then blue. - * - * PNG_FORMAT_FLAG_AFIRST: if set the alpha channel (if present) precedes the - * color or grayscale components. If not set the alpha channel follows the - * components. - * - * You do not have to read directly from a file. You can read from memory or, - * on systems that support it, from a <stdio.h> FILE*. This is controlled by - * the particular png_image_read_from_ function you call at the start. Likewise - * on write you can write to a FILE* if your system supports it. Check the - * macro PNG_STDIO_SUPPORTED to see if stdio support has been included in your - * libpng build. - * - * If you read 16-bit (PNG_FORMAT_FLAG_LINEAR) data you may need to write it in - * the 8-bit format for display. You do this by setting the convert_to_8bit - * flag to 'true'. - * - * Don't repeatedly convert between the 8-bit and 16-bit forms. There is - * significant data loss when 16-bit data is converted to the 8-bit encoding and - * the current libpng implementation of conversion to 16-bit is also - * significantly lossy. The latter will be fixed in the future, but the former - * is unavoidable - the 8-bit format just doesn't have enough resolution. - */ - -/* If your program needs more information from the PNG data it reads, or if you - * need to do more complex transformations, or minimize transformations, on the - * data you read, then you must use one of the several lower level libpng - * interfaces. - * - * All these interfaces require that you do your own error handling - your - * program must be able to arrange for control to return to your own code any - * time libpng encounters a problem. There are several ways to do this, but the - * standard way is to use the ANSI-C (C90) <setjmp.h> interface to establish a - * return point within your own code. You must do this if you do not use the - * simplified interface (above). - * - * The first step is to include the header files you need, including the libpng - * header file. Include any standard headers and feature test macros your - * program requires before including png.h: - */ -#include <png.h> - - /* The png_jmpbuf() macro, used in error handling, became available in - * libpng version 1.0.6. If you want to be able to run your code with older - * versions of libpng, you must define the macro yourself (but only if it - * is not already defined by libpng!). - */ - -#ifndef png_jmpbuf -# define png_jmpbuf(png_ptr) ((png_ptr)->png_jmpbuf) -#endif - -/* Check to see if a file is a PNG file using png_sig_cmp(). png_sig_cmp() - * returns zero if the image is a PNG and nonzero if it isn't a PNG. - * - * The function check_if_png() shown here, but not used, returns nonzero (true) - * if the file can be opened and is a PNG, 0 (false) otherwise. - * - * If this call is successful, and you are going to keep the file open, - * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once - * you have created the png_ptr, so that libpng knows your application - * has read that many bytes from the start of the file. Make sure you - * don't call png_set_sig_bytes() with more than 8 bytes read or give it - * an incorrect number of bytes read, or you will either have read too - * many bytes (your fault), or you are telling libpng to read the wrong - * number of magic bytes (also your fault). - * - * Many applications already read the first 2 or 4 bytes from the start - * of the image to determine the file type, so it would be easiest just - * to pass the bytes to png_sig_cmp() or even skip that if you know - * you have a PNG file, and call png_set_sig_bytes(). - */ -#define PNG_BYTES_TO_CHECK 4 -int check_if_png(char *file_name, FILE **fp) -{ - char buf[PNG_BYTES_TO_CHECK]; - - /* Open the prospective PNG file. */ - if ((*fp = fopen(file_name, "rb")) == NULL) - return 0; - - /* Read in some of the signature bytes */ - if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK) - return 0; - - /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature. - Return nonzero (true) if they match */ - - return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK)); -} - -/* Read a PNG file. You may want to return an error code if the read - * fails (depending upon the failure). There are two "prototypes" given - * here - one where we are given the filename, and we need to open the - * file, and the other where we are given an open file (possibly with - * some or all of the magic bytes read - see comments above). - */ -#ifdef open_file /* prototype 1 */ -void read_png(char *file_name) /* We need to open the file */ -{ - png_structp png_ptr; - png_infop info_ptr; - int sig_read = 0; - png_uint_32 width, height; - int bit_depth, color_type, interlace_type; - FILE *fp; - - if ((fp = fopen(file_name, "rb")) == NULL) - return (ERROR); - -#else no_open_file /* prototype 2 */ -void read_png(FILE *fp, int sig_read) /* File is already open */ -{ - png_structp png_ptr; - png_infop info_ptr; - png_uint_32 width, height; - int bit_depth, color_type, interlace_type; -#endif no_open_file /* Only use one prototype! */ - - /* Create and initialize the png_struct with the desired error handler - * functions. If you want to use the default stderr and longjump method, - * you can supply NULL for the last three parameters. We also supply the - * the compiler header file version, so that we know if the application - * was compiled with a compatible version of the library. REQUIRED - */ - png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, - png_voidp user_error_ptr, user_error_fn, user_warning_fn); - - if (png_ptr == NULL) - { - fclose(fp); - return (ERROR); - } - - /* Allocate/initialize the memory for image information. REQUIRED. */ - info_ptr = png_create_info_struct(png_ptr); - if (info_ptr == NULL) - { - fclose(fp); - png_destroy_read_struct(&png_ptr, NULL, NULL); - return (ERROR); - } - - /* Set error handling if you are using the setjmp/longjmp method (this is - * the normal method of doing things with libpng). REQUIRED unless you - * set up your own error handlers in the png_create_read_struct() earlier. - */ - - if (setjmp(png_jmpbuf(png_ptr))) - { - /* Free all of the memory associated with the png_ptr and info_ptr */ - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); - fclose(fp); - /* If we get here, we had a problem reading the file */ - return (ERROR); - } - - /* One of the following I/O initialization methods is REQUIRED */ -#ifdef streams /* PNG file I/O method 1 */ - /* Set up the input control if you are using standard C streams */ - png_init_io(png_ptr, fp); - -#else no_streams /* PNG file I/O method 2 */ - /* If you are using replacement read functions, instead of calling - * png_init_io() here you would call: - */ - png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn); - /* where user_io_ptr is a structure you want available to the callbacks */ -#endif no_streams /* Use only one I/O method! */ - - /* If we have already read some of the signature */ - png_set_sig_bytes(png_ptr, sig_read); - -#ifdef hilevel - /* - * If you have enough memory to read in the entire image at once, - * and you need to specify only transforms that can be controlled - * with one of the PNG_TRANSFORM_* bits (this presently excludes - * quantizing, filling, setting background, and doing gamma - * adjustment), then you can read the entire image (including - * pixels) into the info structure with this call: - */ - png_read_png(png_ptr, info_ptr, png_transforms, NULL); - -#else - /* OK, you're doing it the hard way, with the lower-level functions */ - - /* The call to png_read_info() gives us all of the information from the - * PNG file before the first IDAT (image data chunk). REQUIRED - */ - png_read_info(png_ptr, info_ptr); - - png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, - &interlace_type, NULL, NULL); - - /* Set up the data transformations you want. Note that these are all - * optional. Only call them if you want/need them. Many of the - * transformations only work on specific types of images, and many - * are mutually exclusive. - */ - - /* Tell libpng to strip 16 bits/color files down to 8 bits/color. - * Use accurate scaling if it's available, otherwise just chop off the - * low byte. - */ -#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED - png_set_scale_16(png_ptr); -#else - png_set_strip_16(png_ptr); -#endif - - /* Strip alpha bytes from the input data without combining with the - * background (not recommended). - */ - png_set_strip_alpha(png_ptr); - - /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single - * byte into separate bytes (useful for paletted and grayscale images). - */ - png_set_packing(png_ptr); - - /* Change the order of packed pixels to least significant bit first - * (not useful if you are using png_set_packing). */ - png_set_packswap(png_ptr); - - /* Expand paletted colors into true RGB triplets */ - if (color_type == PNG_COLOR_TYPE_PALETTE) - png_set_palette_to_rgb(png_ptr); - - /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */ - if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) - png_set_expand_gray_1_2_4_to_8(png_ptr); - - /* Expand paletted or RGB images with transparency to full alpha channels - * so the data will be available as RGBA quartets. - */ - if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) != 0) - png_set_tRNS_to_alpha(png_ptr); - - /* Set the background color to draw transparent and alpha images over. - * It is possible to set the red, green, and blue components directly - * for paletted images instead of supplying a palette index. Note that - * even if the PNG file supplies a background, you are not required to - * use it - you should use the (solid) application background if it has one. - */ - - png_color_16 my_background, *image_background; - - if (png_get_bKGD(png_ptr, info_ptr, &image_background) != 0) - png_set_background(png_ptr, image_background, - PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); - else - png_set_background(png_ptr, &my_background, - PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); - - /* Some suggestions as to how to get a screen gamma value - * - * Note that screen gamma is the display_exponent, which includes - * the CRT_exponent and any correction for viewing conditions - */ - if (/* We have a user-defined screen gamma value */) - { - screen_gamma = user-defined screen_gamma; - } - /* This is one way that applications share the same screen gamma value */ - else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL) - { - screen_gamma = atof(gamma_str); - } - /* If we don't have another value */ - else - { - screen_gamma = PNG_DEFAULT_sRGB; /* A good guess for a PC monitor - in a dimly lit room */ - screen_gamma = PNG_GAMMA_MAC_18 or 1.0; /* Good guesses for Mac systems */ - } - - /* Tell libpng to handle the gamma conversion for you. The final call - * is a good guess for PC generated images, but it should be configurable - * by the user at run time by the user. It is strongly suggested that - * your application support gamma correction. - */ - - int intent; - - if (png_get_sRGB(png_ptr, info_ptr, &intent) != 0) - png_set_gamma(png_ptr, screen_gamma, PNG_DEFAULT_sRGB); - else - { - double image_gamma; - if (png_get_gAMA(png_ptr, info_ptr, &image_gamma) != 0) - png_set_gamma(png_ptr, screen_gamma, image_gamma); - else - png_set_gamma(png_ptr, screen_gamma, 0.45455); - } - -#ifdef PNG_READ_QUANTIZE_SUPPORTED - /* Quantize RGB files down to 8-bit palette or reduce palettes - * to the number of colors available on your screen. - */ - if ((color_type & PNG_COLOR_MASK_COLOR) != 0) - { - int num_palette; - png_colorp palette; - - /* This reduces the image to the application supplied palette */ - if (/* We have our own palette */) - { - /* An array of colors to which the image should be quantized */ - png_color std_color_cube[MAX_SCREEN_COLORS]; - - png_set_quantize(png_ptr, std_color_cube, MAX_SCREEN_COLORS, - MAX_SCREEN_COLORS, NULL, 0); - } - /* This reduces the image to the palette supplied in the file */ - else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) != 0) - { - png_uint_16p histogram = NULL; - - png_get_hIST(png_ptr, info_ptr, &histogram); - - png_set_quantize(png_ptr, palette, num_palette, - max_screen_colors, histogram, 0); - } - } -#endif /* READ_QUANTIZE */ - - /* Invert monochrome files to have 0 as white and 1 as black */ - png_set_invert_mono(png_ptr); - - /* If you want to shift the pixel values from the range [0,255] or - * [0,65535] to the original [0,7] or [0,31], or whatever range the - * colors were originally in: - */ - if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT) != 0) - { - png_color_8p sig_bit_p; - - png_get_sBIT(png_ptr, info_ptr, &sig_bit_p); - png_set_shift(png_ptr, sig_bit_p); - } - - /* Flip the RGB pixels to BGR (or RGBA to BGRA) */ - if ((color_type & PNG_COLOR_MASK_COLOR) != 0) - png_set_bgr(png_ptr); - - /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */ - png_set_swap_alpha(png_ptr); - - /* Swap bytes of 16-bit files to least significant byte first */ - png_set_swap(png_ptr); - - /* Add filler (or alpha) byte (before/after each RGB triplet) */ - png_set_filler(png_ptr, 0xffff, PNG_FILLER_AFTER); - -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Turn on interlace handling. REQUIRED if you are not using - * png_read_image(). To see how to handle interlacing passes, - * see the png_read_row() method below: - */ - number_passes = png_set_interlace_handling(png_ptr); -#else - number_passes = 1; -#endif /* READ_INTERLACING */ - - - /* Optional call to gamma correct and add the background to the palette - * and update info structure. REQUIRED if you are expecting libpng to - * update the palette for you (ie you selected such a transform above). - */ - png_read_update_info(png_ptr, info_ptr); - - /* Allocate the memory to hold the image using the fields of info_ptr. */ - - /* The easiest way to read the image: */ - png_bytep row_pointers[height]; - - /* Clear the pointer array */ - for (row = 0; row < height; row++) - row_pointers[row] = NULL; - - for (row = 0; row < height; row++) - row_pointers[row] = png_malloc(png_ptr, png_get_rowbytes(png_ptr, - info_ptr)); - - /* Now it's time to read the image. One of these methods is REQUIRED */ -#ifdef entire /* Read the entire image in one go */ - png_read_image(png_ptr, row_pointers); - -#else no_entire /* Read the image one or more scanlines at a time */ - /* The other way to read images - deal with interlacing: */ - - for (pass = 0; pass < number_passes; pass++) - { -#ifdef single /* Read the image a single row at a time */ - for (y = 0; y < height; y++) - { - png_read_rows(png_ptr, &row_pointers[y], NULL, 1); - } - -#else no_single /* Read the image several rows at a time */ - for (y = 0; y < height; y += number_of_rows) - { -#ifdef sparkle /* Read the image using the "sparkle" effect. */ - png_read_rows(png_ptr, &row_pointers[y], NULL, - number_of_rows); -#else no_sparkle /* Read the image using the "rectangle" effect */ - png_read_rows(png_ptr, NULL, &row_pointers[y], - number_of_rows); -#endif no_sparkle /* Use only one of these two methods */ - } - - /* If you want to display the image after every pass, do so here */ -#endif no_single /* Use only one of these two methods */ - } -#endif no_entire /* Use only one of these two methods */ - - /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ - png_read_end(png_ptr, info_ptr); -#endif hilevel - - /* At this point you have read the entire image */ - - /* Clean up after the read, and free any memory allocated - REQUIRED */ - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); - - /* Close the file */ - fclose(fp); - - /* That's it */ - return (OK); -} - -/* Progressively read a file */ - -int -initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr) -{ - /* Create and initialize the png_struct with the desired error handler - * functions. If you want to use the default stderr and longjump method, - * you can supply NULL for the last three parameters. We also check that - * the library version is compatible in case we are using dynamically - * linked libraries. - */ - *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, - png_voidp user_error_ptr, user_error_fn, user_warning_fn); - - if (*png_ptr == NULL) - { - *info_ptr = NULL; - return (ERROR); - } - - *info_ptr = png_create_info_struct(png_ptr); - - if (*info_ptr == NULL) - { - png_destroy_read_struct(png_ptr, info_ptr, NULL); - return (ERROR); - } - - if (setjmp(png_jmpbuf((*png_ptr)))) - { - png_destroy_read_struct(png_ptr, info_ptr, NULL); - return (ERROR); - } - - /* This one's new. You will need to provide all three - * function callbacks, even if you aren't using them all. - * If you aren't using all functions, you can specify NULL - * parameters. Even when all three functions are NULL, - * you need to call png_set_progressive_read_fn(). - * These functions shouldn't be dependent on global or - * static variables if you are decoding several images - * simultaneously. You should store stream specific data - * in a separate struct, given as the second parameter, - * and retrieve the pointer from inside the callbacks using - * the function png_get_progressive_ptr(png_ptr). - */ - png_set_progressive_read_fn(*png_ptr, (void *)stream_data, - info_callback, row_callback, end_callback); - - return (OK); -} - -int -process_data(png_structp *png_ptr, png_infop *info_ptr, - png_bytep buffer, png_uint_32 length) -{ - if (setjmp(png_jmpbuf((*png_ptr)))) - { - /* Free the png_ptr and info_ptr memory on error */ - png_destroy_read_struct(png_ptr, info_ptr, NULL); - return (ERROR); - } - - /* This one's new also. Simply give it chunks of data as - * they arrive from the data stream (in order, of course). - * On segmented machines, don't give it any more than 64K. - * The library seems to run fine with sizes of 4K, although - * you can give it much less if necessary (I assume you can - * give it chunks of 1 byte, but I haven't tried with less - * than 256 bytes yet). When this function returns, you may - * want to display any rows that were generated in the row - * callback, if you aren't already displaying them there. - */ - png_process_data(*png_ptr, *info_ptr, buffer, length); - return (OK); -} - -info_callback(png_structp png_ptr, png_infop info) -{ - /* Do any setup here, including setting any of the transformations - * mentioned in the Reading PNG files section. For now, you _must_ - * call either png_start_read_image() or png_read_update_info() - * after all the transformations are set (even if you don't set - * any). You may start getting rows before png_process_data() - * returns, so this is your last chance to prepare for that. - */ -} - -row_callback(png_structp png_ptr, png_bytep new_row, - png_uint_32 row_num, int pass) -{ - /* - * This function is called for every row in the image. If the - * image is interlaced, and you turned on the interlace handler, - * this function will be called for every row in every pass. - * - * In this function you will receive a pointer to new row data from - * libpng called new_row that is to replace a corresponding row (of - * the same data format) in a buffer allocated by your application. - * - * The new row data pointer "new_row" may be NULL, indicating there is - * no new data to be replaced (in cases of interlace loading). - * - * If new_row is not NULL then you need to call - * png_progressive_combine_row() to replace the corresponding row as - * shown below: - */ - - /* Get pointer to corresponding row in our - * PNG read buffer. - */ - png_bytep old_row = ((png_bytep *)our_data)[row_num]; - -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* If both rows are allocated then copy the new row - * data to the corresponding row data. - */ - if ((old_row != NULL) && (new_row != NULL)) - png_progressive_combine_row(png_ptr, old_row, new_row); - - /* - * The rows and passes are called in order, so you don't really - * need the row_num and pass, but I'm supplying them because it - * may make your life easier. - * - * For the non-NULL rows of interlaced images, you must call - * png_progressive_combine_row() passing in the new row and the - * old row, as demonstrated above. You can call this function for - * NULL rows (it will just return) and for non-interlaced images - * (it just does the memcpy for you) if it will make the code - * easier. Thus, you can just do this for all cases: - */ - - png_progressive_combine_row(png_ptr, old_row, new_row); - - /* where old_row is what was displayed for previous rows. Note - * that the first pass (pass == 0 really) will completely cover - * the old row, so the rows do not have to be initialized. After - * the first pass (and only for interlaced images), you will have - * to pass the current row as new_row, and the function will combine - * the old row and the new row. - */ -#endif /* READ_INTERLACING */ -} - -end_callback(png_structp png_ptr, png_infop info) -{ - /* This function is called when the whole image has been read, - * including any chunks after the image (up to and including - * the IEND). You will usually have the same info chunk as you - * had in the header, although some data may have been added - * to the comments and time fields. - * - * Most people won't do much here, perhaps setting a flag that - * marks the image as finished. - */ -} - -/* Write a png file */ -void write_png(char *file_name /* , ... other image information ... */) -{ - FILE *fp; - png_structp png_ptr; - png_infop info_ptr; - png_colorp palette; - - /* Open the file */ - fp = fopen(file_name, "wb"); - if (fp == NULL) - return (ERROR); - - /* Create and initialize the png_struct with the desired error handler - * functions. If you want to use the default stderr and longjump method, - * you can supply NULL for the last three parameters. We also check that - * the library version is compatible with the one used at compile time, - * in case we are using dynamically linked libraries. REQUIRED. - */ - png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, - png_voidp user_error_ptr, user_error_fn, user_warning_fn); - - if (png_ptr == NULL) - { - fclose(fp); - return (ERROR); - } - - /* Allocate/initialize the image information data. REQUIRED */ - info_ptr = png_create_info_struct(png_ptr); - if (info_ptr == NULL) - { - fclose(fp); - png_destroy_write_struct(&png_ptr, NULL); - return (ERROR); - } - - /* Set error handling. REQUIRED if you aren't supplying your own - * error handling functions in the png_create_write_struct() call. - */ - if (setjmp(png_jmpbuf(png_ptr))) - { - /* If we get here, we had a problem writing the file */ - fclose(fp); - png_destroy_write_struct(&png_ptr, &info_ptr); - return (ERROR); - } - - /* One of the following I/O initialization functions is REQUIRED */ - -#ifdef streams /* I/O initialization method 1 */ - /* Set up the output control if you are using standard C streams */ - png_init_io(png_ptr, fp); - -#else no_streams /* I/O initialization method 2 */ - /* If you are using replacement write functions, instead of calling - * png_init_io() here you would call - */ - png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn, - user_IO_flush_function); - /* where user_io_ptr is a structure you want available to the callbacks */ -#endif no_streams /* Only use one initialization method */ - -#ifdef hilevel - /* This is the easy way. Use it if you already have all the - * image info living in the structure. You could "|" many - * PNG_TRANSFORM flags into the png_transforms integer here. - */ - png_write_png(png_ptr, info_ptr, png_transforms, NULL); - -#else - /* This is the hard way */ - - /* Set the image information here. Width and height are up to 2^31, - * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on - * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY, - * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB, - * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or - * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST - * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED - */ - png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, PNG_COLOR_TYPE_???, - PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - - /* Set the palette if there is one. REQUIRED for indexed-color images */ - palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH - * (sizeof (png_color))); - /* ... Set palette colors ... */ - png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH); - /* You must not free palette here, because png_set_PLTE only makes a link to - * the palette that you malloced. Wait until you are about to destroy - * the png structure. - */ - - /* Optional significant bit (sBIT) chunk */ - png_color_8 sig_bit; - - /* If we are dealing with a grayscale image then */ - sig_bit.gray = true_bit_depth; - - /* Otherwise, if we are dealing with a color image then */ - sig_bit.red = true_red_bit_depth; - sig_bit.green = true_green_bit_depth; - sig_bit.blue = true_blue_bit_depth; - - /* If the image has an alpha channel then */ - sig_bit.alpha = true_alpha_bit_depth; - - png_set_sBIT(png_ptr, info_ptr, &sig_bit); - - - /* Optional gamma chunk is strongly suggested if you have any guess - * as to the correct gamma of the image. - */ - png_set_gAMA(png_ptr, info_ptr, gamma); - - /* Optionally write comments into the image */ - { - png_text text_ptr[3]; - - char key0[]="Title"; - char text0[]="Mona Lisa"; - text_ptr[0].key = key0; - text_ptr[0].text = text0; - text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE; - text_ptr[0].itxt_length = 0; - text_ptr[0].lang = NULL; - text_ptr[0].lang_key = NULL; - - char key1[]="Author"; - char text1[]="Leonardo DaVinci"; - text_ptr[1].key = key1; - text_ptr[1].text = text1; - text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE; - text_ptr[1].itxt_length = 0; - text_ptr[1].lang = NULL; - text_ptr[1].lang_key = NULL; - - char key2[]="Description"; - char text2[]="<long text>"; - text_ptr[2].key = key2; - text_ptr[2].text = text2; - text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt; - text_ptr[2].itxt_length = 0; - text_ptr[2].lang = NULL; - text_ptr[2].lang_key = NULL; - - png_set_text(write_ptr, write_info_ptr, text_ptr, 3); - } - - /* Other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs */ - - /* Note that if sRGB is present the gAMA and cHRM chunks must be ignored - * on read and, if your application chooses to write them, they must - * be written in accordance with the sRGB profile - */ - - /* Write the file header information. REQUIRED */ - png_write_info(png_ptr, info_ptr); - - /* If you want, you can write the info in two steps, in case you need to - * write your private chunk ahead of PLTE: - * - * png_write_info_before_PLTE(write_ptr, write_info_ptr); - * write_my_chunk(); - * png_write_info(png_ptr, info_ptr); - * - * However, given the level of known- and unknown-chunk support in 1.2.0 - * and up, this should no longer be necessary. - */ - - /* Once we write out the header, the compression type on the text - * chunk gets changed to PNG_TEXT_COMPRESSION_NONE_WR or - * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again - * at the end. - */ - - /* Set up the transformations you want. Note that these are - * all optional. Only call them if you want them. - */ - - /* Invert monochrome pixels */ - png_set_invert_mono(png_ptr); - - /* Shift the pixels up to a legal bit depth and fill in - * as appropriate to correctly scale the image. - */ - png_set_shift(png_ptr, &sig_bit); - - /* Pack pixels into bytes */ - png_set_packing(png_ptr); - - /* Swap location of alpha bytes from ARGB to RGBA */ - png_set_swap_alpha(png_ptr); - - /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into - * RGB (4 channels -> 3 channels). The second parameter is not used. - */ - png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); - - /* Flip BGR pixels to RGB */ - png_set_bgr(png_ptr); - - /* Swap bytes of 16-bit files to most significant byte first */ - png_set_swap(png_ptr); - - /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */ - png_set_packswap(png_ptr); - - /* Turn on interlace handling if you are not using png_write_image() */ - if (interlacing != 0) - number_passes = png_set_interlace_handling(png_ptr); - - else - number_passes = 1; - - /* The easiest way to write the image (you may have a different memory - * layout, however, so choose what fits your needs best). You need to - * use the first method if you aren't handling interlacing yourself. - */ - png_uint_32 k, height, width; - - /* In this example, "image" is a one-dimensional array of bytes */ - png_byte image[height*width*bytes_per_pixel]; - - png_bytep row_pointers[height]; - - if (height > PNG_UINT_32_MAX/(sizeof (png_bytep))) - png_error (png_ptr, "Image is too tall to process in memory"); - - /* Set up pointers into your "image" byte array */ - for (k = 0; k < height; k++) - row_pointers[k] = image + k*width*bytes_per_pixel; - - /* One of the following output methods is REQUIRED */ - -#ifdef entire /* Write out the entire image data in one call */ - png_write_image(png_ptr, row_pointers); - - /* The other way to write the image - deal with interlacing */ - -#else no_entire /* Write out the image data by one or more scanlines */ - - /* The number of passes is either 1 for non-interlaced images, - * or 7 for interlaced images. - */ - for (pass = 0; pass < number_passes; pass++) - { - /* Write a few rows at a time. */ - png_write_rows(png_ptr, &row_pointers[first_row], number_of_rows); - - /* If you are only writing one row at a time, this works */ - for (y = 0; y < height; y++) - png_write_rows(png_ptr, &row_pointers[y], 1); - } -#endif no_entire /* Use only one output method */ - - /* You can write optional chunks like tEXt, zTXt, and tIME at the end - * as well. Shouldn't be necessary in 1.2.0 and up as all the public - * chunks are supported and you can use png_set_unknown_chunks() to - * register unknown chunks into the info structure to be written out. - */ - - /* It is REQUIRED to call this to finish writing the rest of the file */ - png_write_end(png_ptr, info_ptr); -#endif hilevel - - /* If you png_malloced a palette, free it here (don't free info_ptr->palette, - * as recommended in versions 1.0.5m and earlier of this example; if - * libpng mallocs info_ptr->palette, libpng will free it). If you - * allocated it with malloc() instead of png_malloc(), use free() instead - * of png_free(). - */ - png_free(png_ptr, palette); - palette = NULL; - - /* Similarly, if you png_malloced any data that you passed in with - * png_set_something(), such as a hist or trans array, free it here, - * when you can be sure that libpng is through with it. - */ - png_free(png_ptr, trans); - trans = NULL; - /* Whenever you use png_free() it is a good idea to set the pointer to - * NULL in case your application inadvertently tries to png_free() it - * again. When png_free() sees a NULL it returns without action, thus - * avoiding the double-free security problem. - */ - - /* Clean up after the write, and free any memory allocated */ - png_destroy_write_struct(&png_ptr, &info_ptr); - - /* Close the file */ - fclose(fp); - - /* That's it */ - return (OK); -} - -#endif /* if 0 */ diff --git a/third_party/libpng/libpng-manual.txt b/third_party/libpng/libpng-manual.txt deleted file mode 100644 index 98dc275339..0000000000 --- a/third_party/libpng/libpng-manual.txt +++ /dev/null @@ -1,5395 +0,0 @@ -libpng-manual.txt - A description on how to use and modify libpng - - libpng version 1.6.22rc01 - May 14, 2016 - Updated and distributed by Glenn Randers-Pehrson - <glennrp at users.sourceforge.net> - Copyright (c) 1998-2016 Glenn Randers-Pehrson - - This document is released under the libpng license. - For conditions of distribution and use, see the disclaimer - and license in png.h - - Based on: - - libpng versions 0.97, January 1998, through 1.6.22rc01 - May 14, 2016 - Updated and distributed by Glenn Randers-Pehrson - Copyright (c) 1998-2016 Glenn Randers-Pehrson - - libpng 1.0 beta 6 - version 0.96 - May 28, 1997 - Updated and distributed by Andreas Dilger - Copyright (c) 1996, 1997 Andreas Dilger - - libpng 1.0 beta 2 - version 0.88 - January 26, 1996 - For conditions of distribution and use, see copyright - notice in png.h. Copyright (c) 1995, 1996 Guy Eric - Schalnat, Group 42, Inc. - - Updated/rewritten per request in the libpng FAQ - Copyright (c) 1995, 1996 Frank J. T. Wojcik - December 18, 1995 & January 20, 1996 - - TABLE OF CONTENTS - - I. Introduction - II. Structures - III. Reading - IV. Writing - V. Simplified API - VI. Modifying/Customizing libpng - VII. MNG support - VIII. Changes to Libpng from version 0.88 - IX. Changes to Libpng from version 1.0.x to 1.2.x - X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x - XI. Changes to Libpng from version 1.4.x to 1.5.x - XII. Changes to Libpng from version 1.5.x to 1.6.x - XIII. Detecting libpng - XIV. Source code repository - XV. Coding style - XVI. Y2K Compliance in libpng - -I. Introduction - -This file describes how to use and modify the PNG reference library -(known as libpng) for your own use. In addition to this -file, example.c is a good starting point for using the library, as -it is heavily commented and should include everything most people -will need. We assume that libpng is already installed; see the -INSTALL file for instructions on how to configure and install libpng. - -For examples of libpng usage, see the files "example.c", "pngtest.c", -and the files in the "contrib" directory, all of which are included in -the libpng distribution. - -Libpng was written as a companion to the PNG specification, as a way -of reducing the amount of time and effort it takes to support the PNG -file format in application programs. - -The PNG specification (second edition), November 2003, is available as -a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at -<http://www.w3.org/TR/2003/REC-PNG-20031110/ -The W3C and ISO documents have identical technical content. - -The PNG-1.2 specification is available at -<http://png-mng.sourceforge.net/pub/png/spec/1.2/>. -It is technically equivalent -to the PNG specification (second edition) but has some additional material. - -The PNG-1.0 specification is available as RFC 2083 -<http://png-mng.sourceforge.net/pub/png/spec/1.0/> and as a -W3C Recommendation <http://www.w3.org/TR/REC-png-961001>. - -Some additional chunks are described in the special-purpose public chunks -documents at <http://www.libpng.org/pub/png/spec/register/> - -Other information -about PNG, and the latest version of libpng, can be found at the PNG home -page, <http://www.libpng.org/pub/png/>. - -Most users will not have to modify the library significantly; advanced -users may want to modify it more. All attempts were made to make it as -complete as possible, while keeping the code easy to understand. -Currently, this library only supports C. Support for other languages -is being considered. - -Libpng has been designed to handle multiple sessions at one time, -to be easily modifiable, to be portable to the vast majority of -machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy -to use. The ultimate goal of libpng is to promote the acceptance of -the PNG file format in whatever way possible. While there is still -work to be done (see the TODO file), libpng should cover the -majority of the needs of its users. - -Libpng uses zlib for its compression and decompression of PNG files. -Further information about zlib, and the latest version of zlib, can -be found at the zlib home page, <http://zlib.net/>. -The zlib compression utility is a general purpose utility that is -useful for more than PNG files, and can be used without libpng. -See the documentation delivered with zlib for more details. -You can usually find the source files for the zlib utility wherever you -find the libpng source files. - -Libpng is thread safe, provided the threads are using different -instances of the structures. Each thread should have its own -png_struct and png_info instances, and thus its own image. -Libpng does not protect itself against two threads using the -same instance of a structure. - -II. Structures - -There are two main structures that are important to libpng, png_struct -and png_info. Both are internal structures that are no longer exposed -in the libpng interface (as of libpng 1.5.0). - -The png_info structure is designed to provide information about the -PNG file. At one time, the fields of png_info were intended to be -directly accessible to the user. However, this tended to cause problems -with applications using dynamically loaded libraries, and as a result -a set of interface functions for png_info (the png_get_*() and png_set_*() -functions) was developed, and direct access to the png_info fields was -deprecated.. - -The png_struct structure is the object used by the library to decode a -single image. As of 1.5.0 this structure is also not exposed. - -Almost all libpng APIs require a pointer to a png_struct as the first argument. -Many (in particular the png_set and png_get APIs) also require a pointer -to png_info as the second argument. Some application visible macros -defined in png.h designed for basic data access (reading and writing -integers in the PNG format) don't take a png_info pointer, but it's almost -always safe to assume that a (png_struct*) has to be passed to call an API -function. - -You can have more than one png_info structure associated with an image, -as illustrated in pngtest.c, one for information valid prior to the -IDAT chunks and another (called "end_info" below) for things after them. - -The png.h header file is an invaluable reference for programming with libpng. -And while I'm on the topic, make sure you include the libpng header file: - -#include <png.h> - -and also (as of libpng-1.5.0) the zlib header file, if you need it: - -#include <zlib.h> - -Types - -The png.h header file defines a number of integral types used by the -APIs. Most of these are fairly obvious; for example types corresponding -to integers of particular sizes and types for passing color values. - -One exception is how non-integral numbers are handled. For application -convenience most APIs that take such numbers have C (double) arguments; -however, internally PNG, and libpng, use 32 bit signed integers and encode -the value by multiplying by 100,000. As of libpng 1.5.0 a convenience -macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point) -which is simply (png_int_32). - -All APIs that take (double) arguments also have a matching API that -takes the corresponding fixed point integer arguments. The fixed point -API has the same name as the floating point one with "_fixed" appended. -The actual range of values permitted in the APIs is frequently less than -the full range of (png_fixed_point) (-21474 to +21474). When APIs require -a non-negative argument the type is recorded as png_uint_32 above. Consult -the header file and the text below for more information. - -Special care must be take with sCAL chunk handling because the chunk itself -uses non-integral values encoded as strings containing decimal floating point -numbers. See the comments in the header file. - -Configuration - -The main header file function declarations are frequently protected by C -preprocessing directives of the form: - - #ifdef PNG_feature_SUPPORTED - declare-function - #endif - ... - #ifdef PNG_feature_SUPPORTED - use-function - #endif - -The library can be built without support for these APIs, although a -standard build will have all implemented APIs. Application programs -should check the feature macros before using an API for maximum -portability. From libpng 1.5.0 the feature macros set during the build -of libpng are recorded in the header file "pnglibconf.h" and this file -is always included by png.h. - -If you don't need to change the library configuration from the default, skip to -the next section ("Reading"). - -Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all -of the build project files in the 'projects' directory simply copy -scripts/pnglibconf.h.prebuilt to pnglibconf.h. This means that these build -systems do not permit easy auto-configuration of the library - they only -support the default configuration. - -The easiest way to make minor changes to the libpng configuration when -auto-configuration is supported is to add definitions to the command line -using (typically) CPPFLAGS. For example: - -CPPFLAGS=-DPNG_NO_FLOATING_ARITHMETIC - -will change the internal libpng math implementation for gamma correction and -other arithmetic calculations to fixed point, avoiding the need for fast -floating point support. The result can be seen in the generated pnglibconf.h - -make sure it contains the changed feature macro setting. - -If you need to make more extensive configuration changes - more than one or two -feature macro settings - you can either add -DPNG_USER_CONFIG to the build -command line and put a list of feature macro settings in pngusr.h or you can set -DFA_XTRA (a makefile variable) to a file containing the same information in the -form of 'option' settings. - -A. Changing pnglibconf.h - -A variety of methods exist to build libpng. Not all of these support -reconfiguration of pnglibconf.h. To reconfigure pnglibconf.h it must either be -rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand. - -Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt to -pnglibconf.h and changing the lines defining the supported features, paying -very close attention to the 'option' information in scripts/pnglibconf.dfa -that describes those features and their requirements. This is easy to get -wrong. - -B. Configuration using DFA_XTRA - -Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later -variant such as 'nawk' or 'gawk', is available. The configure build will -automatically find an appropriate awk and build pnglibconf.h. -The scripts/pnglibconf.mak file contains a set of make rules for doing the -same thing if configure is not used, and many of the makefiles in the scripts -directory use this approach. - -When rebuilding simply write a new file containing changed options and set -DFA_XTRA to the name of this file. This causes the build to append the new file -to the end of scripts/pnglibconf.dfa. The pngusr.dfa file should contain lines -of the following forms: - -everything = off - -This turns all optional features off. Include it at the start of pngusr.dfa to -make it easier to build a minimal configuration. You will need to turn at least -some features on afterward to enable either reading or writing code, or both. - -option feature on -option feature off - -Enable or disable a single feature. This will automatically enable other -features required by a feature that is turned on or disable other features that -require a feature which is turned off. Conflicting settings will cause an error -message to be emitted by awk. - -setting feature default value - -Changes the default value of setting 'feature' to 'value'. There are a small -number of settings listed at the top of pnglibconf.h, they are documented in the -source code. Most of these values have performance implications for the library -but most of them have no visible effect on the API. Some can also be overridden -from the API. - -This method of building a customized pnglibconf.h is illustrated in -contrib/pngminim/*. See the "$(PNGCONF):" target in the makefile and -pngusr.dfa in these directories. - -C. Configuration using PNG_USER_CONFIG - -If -DPNG_USER_CONFIG is added to the CPPFLAGS when pnglibconf.h is built, -the file pngusr.h will automatically be included before the options in -scripts/pnglibconf.dfa are processed. Your pngusr.h file should contain only -macro definitions turning features on or off or setting settings. - -Apart from the global setting "everything = off" all the options listed above -can be set using macros in pngusr.h: - -#define PNG_feature_SUPPORTED - -is equivalent to: - -option feature on - -#define PNG_NO_feature - -is equivalent to: - -option feature off - -#define PNG_feature value - -is equivalent to: - -setting feature default value - -Notice that in both cases, pngusr.dfa and pngusr.h, the contents of the -pngusr file you supply override the contents of scripts/pnglibconf.dfa - -If confusing or incomprehensible behavior results it is possible to -examine the intermediate file pnglibconf.dfn to find the full set of -dependency information for each setting and option. Simply locate the -feature in the file and read the C comments that precede it. - -This method is also illustrated in the contrib/pngminim/* makefiles and -pngusr.h. - -III. Reading - -We'll now walk you through the possible functions to call when reading -in a PNG file sequentially, briefly explaining the syntax and purpose -of each one. See example.c and png.h for more detail. While -progressive reading is covered in the next section, you will still -need some of the functions discussed in this section to read a PNG -file. - -Setup - -You will want to do the I/O initialization(*) before you get into libpng, -so if it doesn't work, you don't have much to undo. Of course, you -will also want to insure that you are, in fact, dealing with a PNG -file. Libpng provides a simple check to see if a file is a PNG file. -To use it, pass in the first 1 to 8 bytes of the file to the function -png_sig_cmp(), and it will return 0 (false) if the bytes match the -corresponding bytes of the PNG signature, or nonzero (true) otherwise. -Of course, the more bytes you pass in, the greater the accuracy of the -prediction. - -If you are intending to keep the file pointer open for use in libpng, -you must ensure you don't read more than 8 bytes from the beginning -of the file, and you also have to make a call to png_set_sig_bytes() -with the number of bytes you read from the beginning. Libpng will -then only check the bytes (if any) that your program didn't read. - -(*): If you are not using the standard I/O functions, you will need -to replace them with custom functions. See the discussion under -Customizing libpng. - - FILE *fp = fopen(file_name, "rb"); - if (!fp) - { - return (ERROR); - } - - if (fread(header, 1, number, fp) != number) - { - return (ERROR); - } - - is_png = !png_sig_cmp(header, 0, number); - if (!is_png) - { - return (NOT_PNG); - } - -Next, png_struct and png_info need to be allocated and initialized. In -order to ensure that the size of these structures is correct even with a -dynamically linked libpng, there are functions to initialize and -allocate the structures. We also pass the library version, optional -pointers to error handling functions, and a pointer to a data struct for -use by the error functions, if necessary (the pointer and functions can -be NULL if the default error handlers are to be used). See the section -on Changes to Libpng below regarding the old initialization functions. -The structure allocation functions quietly return NULL if they fail to -create the structure, so your application should check for that. - - png_structp png_ptr = png_create_read_struct - (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, - user_error_fn, user_warning_fn); - - if (!png_ptr) - return (ERROR); - - png_infop info_ptr = png_create_info_struct(png_ptr); - - if (!info_ptr) - { - png_destroy_read_struct(&png_ptr, - (png_infopp)NULL, (png_infopp)NULL); - return (ERROR); - } - -If you want to use your own memory allocation routines, -use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use -png_create_read_struct_2() instead of png_create_read_struct(): - - png_structp png_ptr = png_create_read_struct_2 - (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, - user_error_fn, user_warning_fn, (png_voidp) - user_mem_ptr, user_malloc_fn, user_free_fn); - -The error handling routines passed to png_create_read_struct() -and the memory alloc/free routines passed to png_create_struct_2() -are only necessary if you are not using the libpng supplied error -handling and memory alloc/free functions. - -When libpng encounters an error, it expects to longjmp back -to your routine. Therefore, you will need to call setjmp and pass -your png_jmpbuf(png_ptr). If you read the file from different -routines, you will need to update the longjmp buffer every time you enter -a new routine that will call a png_*() function. - -See your documentation of setjmp/longjmp for your compiler for more -information on setjmp/longjmp. See the discussion on libpng error -handling in the Customizing Libpng section below for more information -on the libpng error handling. If an error occurs, and libpng longjmp's -back to your setjmp, you will want to call png_destroy_read_struct() to -free any memory. - - if (setjmp(png_jmpbuf(png_ptr))) - { - png_destroy_read_struct(&png_ptr, &info_ptr, - &end_info); - fclose(fp); - return (ERROR); - } - -Pass (png_infopp)NULL instead of &end_info if you didn't create -an end_info structure. - -If you would rather avoid the complexity of setjmp/longjmp issues, -you can compile libpng with PNG_NO_SETJMP, in which case -errors will result in a call to PNG_ABORT() which defaults to abort(). - -You can #define PNG_ABORT() to a function that does something -more useful than abort(), as long as your function does not -return. - -Now you need to set up the input code. The default for libpng is to -use the C function fread(). If you use this, you will need to pass a -valid FILE * in the function png_init_io(). Be sure that the file is -opened in binary mode. If you wish to handle reading data in another -way, you need not call the png_init_io() function, but you must then -implement the libpng I/O methods discussed in the Customizing Libpng -section below. - - png_init_io(png_ptr, fp); - -If you had previously opened the file and read any of the signature from -the beginning in order to see if this was a PNG file, you need to let -libpng know that there are some bytes missing from the start of the file. - - png_set_sig_bytes(png_ptr, number); - -You can change the zlib compression buffer size to be used while -reading compressed data with - - png_set_compression_buffer_size(png_ptr, buffer_size); - -where the default size is 8192 bytes. Note that the buffer size -is changed immediately and the buffer is reallocated immediately, -instead of setting a flag to be acted upon later. - -If you want CRC errors to be handled in a different manner than -the default, use - - png_set_crc_action(png_ptr, crit_action, ancil_action); - -The values for png_set_crc_action() say how libpng is to handle CRC errors in -ancillary and critical chunks, and whether to use the data contained -therein. Note that it is impossible to "discard" data in a critical -chunk. - -Choices for (int) crit_action are - PNG_CRC_DEFAULT 0 error/quit - PNG_CRC_ERROR_QUIT 1 error/quit - PNG_CRC_WARN_USE 3 warn/use data - PNG_CRC_QUIET_USE 4 quiet/use data - PNG_CRC_NO_CHANGE 5 use the current value - -Choices for (int) ancil_action are - PNG_CRC_DEFAULT 0 error/quit - PNG_CRC_ERROR_QUIT 1 error/quit - PNG_CRC_WARN_DISCARD 2 warn/discard data - PNG_CRC_WARN_USE 3 warn/use data - PNG_CRC_QUIET_USE 4 quiet/use data - PNG_CRC_NO_CHANGE 5 use the current value - -Setting up callback code - -You can set up a callback function to handle any unknown chunks in the -input stream. You must supply the function - - read_chunk_callback(png_structp png_ptr, - png_unknown_chunkp chunk); - { - /* The unknown chunk structure contains your - chunk data, along with similar data for any other - unknown chunks: */ - - png_byte name[5]; - png_byte *data; - png_size_t size; - - /* Note that libpng has already taken care of - the CRC handling */ - - /* put your code here. Search for your chunk in the - unknown chunk structure, process it, and return one - of the following: */ - - return (-n); /* chunk had an error */ - return (0); /* did not recognize */ - return (n); /* success */ - } - -(You can give your function another name that you like instead of -"read_chunk_callback") - -To inform libpng about your function, use - - png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr, - read_chunk_callback); - -This names not only the callback function, but also a user pointer that -you can retrieve with - - png_get_user_chunk_ptr(png_ptr); - -If you call the png_set_read_user_chunk_fn() function, then all unknown -chunks which the callback does not handle will be saved when read. You can -cause them to be discarded by returning '1' ("handled") instead of '0'. This -behavior will change in libpng 1.7 and the default handling set by the -png_set_keep_unknown_chunks() function, described below, will be used when the -callback returns 0. If you want the existing behavior you should set the global -default to PNG_HANDLE_CHUNK_IF_SAFE now; this is compatible with all current -versions of libpng and with 1.7. Libpng 1.6 issues a warning if you keep the -default, or PNG_HANDLE_CHUNK_NEVER, and the callback returns 0. - -At this point, you can set up a callback function that will be -called after each row has been read, which you can use to control -a progress meter or the like. It's demonstrated in pngtest.c. -You must supply a function - - void read_row_callback(png_structp png_ptr, - png_uint_32 row, int pass); - { - /* put your code here */ - } - -(You can give it another name that you like instead of "read_row_callback") - -To inform libpng about your function, use - - png_set_read_status_fn(png_ptr, read_row_callback); - -When this function is called the row has already been completely processed and -the 'row' and 'pass' refer to the next row to be handled. For the -non-interlaced case the row that was just handled is simply one less than the -passed in row number, and pass will always be 0. For the interlaced case the -same applies unless the row value is 0, in which case the row just handled was -the last one from one of the preceding passes. Because interlacing may skip a -pass you cannot be sure that the preceding pass is just 'pass-1', if you really -need to know what the last pass is record (row,pass) from the callback and use -the last recorded value each time. - -As with the user transform you can find the output row using the -PNG_ROW_FROM_PASS_ROW macro. - -Unknown-chunk handling - -Now you get to set the way the library processes unknown chunks in the -input PNG stream. Both known and unknown chunks will be read. Normal -behavior is that known chunks will be parsed into information in -various info_ptr members while unknown chunks will be discarded. This -behavior can be wasteful if your application will never use some known -chunk types. To change this, you can call: - - png_set_keep_unknown_chunks(png_ptr, keep, - chunk_list, num_chunks); - - keep - 0: default unknown chunk handling - 1: ignore; do not keep - 2: keep only if safe-to-copy - 3: keep even if unsafe-to-copy - - You can use these definitions: - PNG_HANDLE_CHUNK_AS_DEFAULT 0 - PNG_HANDLE_CHUNK_NEVER 1 - PNG_HANDLE_CHUNK_IF_SAFE 2 - PNG_HANDLE_CHUNK_ALWAYS 3 - - chunk_list - list of chunks affected (a byte string, - five bytes per chunk, NULL or '\0' if - num_chunks is positive; ignored if - numchunks <= 0). - - num_chunks - number of chunks affected; if 0, all - unknown chunks are affected. If positive, - only the chunks in the list are affected, - and if negative all unknown chunks and - all known chunks except for the IHDR, - PLTE, tRNS, IDAT, and IEND chunks are - affected. - -Unknown chunks declared in this way will be saved as raw data onto a -list of png_unknown_chunk structures. If a chunk that is normally -known to libpng is named in the list, it will be handled as unknown, -according to the "keep" directive. If a chunk is named in successive -instances of png_set_keep_unknown_chunks(), the final instance will -take precedence. The IHDR and IEND chunks should not be named in -chunk_list; if they are, libpng will process them normally anyway. -If you know that your application will never make use of some particular -chunks, use PNG_HANDLE_CHUNK_NEVER (or 1) as demonstrated below. - -Here is an example of the usage of png_set_keep_unknown_chunks(), -where the private "vpAg" chunk will later be processed by a user chunk -callback function: - - png_byte vpAg[5]={118, 112, 65, 103, (png_byte) '\0'}; - - #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) - png_byte unused_chunks[]= - { - 104, 73, 83, 84, (png_byte) '\0', /* hIST */ - 105, 84, 88, 116, (png_byte) '\0', /* iTXt */ - 112, 67, 65, 76, (png_byte) '\0', /* pCAL */ - 115, 67, 65, 76, (png_byte) '\0', /* sCAL */ - 115, 80, 76, 84, (png_byte) '\0', /* sPLT */ - 116, 73, 77, 69, (png_byte) '\0', /* tIME */ - }; - #endif - - ... - - #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) - /* ignore all unknown chunks - * (use global setting "2" for libpng16 and earlier): - */ - png_set_keep_unknown_chunks(read_ptr, 2, NULL, 0); - - /* except for vpAg: */ - png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1); - - /* also ignore unused known chunks: */ - png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks, - (int)(sizeof unused_chunks)/5); - #endif - -User limits - -The PNG specification allows the width and height of an image to be as -large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns. -For safety, libpng imposes a default limit of 1 million rows and columns. -Larger images will be rejected immediately with a png_error() call. If -you wish to change these limits, you can use - - png_set_user_limits(png_ptr, width_max, height_max); - -to set your own limits (libpng may reject some very wide images -anyway because of potential buffer overflow conditions). - -You should put this statement after you create the PNG structure and -before calling png_read_info(), png_read_png(), or png_process_data(). - -When writing a PNG datastream, put this statement before calling -png_write_info() or png_write_png(). - -If you need to retrieve the limits that are being applied, use - - width_max = png_get_user_width_max(png_ptr); - height_max = png_get_user_height_max(png_ptr); - -The PNG specification sets no limit on the number of ancillary chunks -allowed in a PNG datastream. By default, libpng imposes a limit of -a total of 1000 sPLT, tEXt, iTXt, zTXt, and unknown chunks to be stored. -If you have set up both info_ptr and end_info_ptr, the limit applies -separately to each. You can change the limit on the total number of such -chunks that will be stored, with - - png_set_chunk_cache_max(png_ptr, user_chunk_cache_max); - -where 0x7fffffffL means unlimited. You can retrieve this limit with - - chunk_cache_max = png_get_chunk_cache_max(png_ptr); - -Libpng imposes a limit of 8 Megabytes (8,000,000 bytes) on the amount of -memory that a compressed chunk other than IDAT can occupy, when decompressed. -You can change this limit with - - png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max); - -and you can retrieve the limit with - - chunk_malloc_max = png_get_chunk_malloc_max(png_ptr); - -Any chunks that would cause either of these limits to be exceeded will -be ignored. - -Information about your system - -If you intend to display the PNG or to incorporate it in other image data you -need to tell libpng information about your display or drawing surface so that -libpng can convert the values in the image to match the display. - -From libpng-1.5.4 this information can be set before reading the PNG file -header. In earlier versions png_set_gamma() existed but behaved incorrectly if -called before the PNG file header had been read and png_set_alpha_mode() did not -exist. - -If you need to support versions prior to libpng-1.5.4 test the version number -as illustrated below using "PNG_LIBPNG_VER >= 10504" and follow the procedures -described in the appropriate manual page. - -You give libpng the encoding expected by your system expressed as a 'gamma' -value. You can also specify a default encoding for the PNG file in -case the required information is missing from the file. By default libpng -assumes that the PNG data matches your system, to keep this default call: - - png_set_gamma(png_ptr, screen_gamma, output_gamma); - -or you can use the fixed point equivalent: - - png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, - PNG_FP_1*output_gamma); - -If you don't know the gamma for your system it is probably 2.2 - a good -approximation to the IEC standard for display systems (sRGB). If images are -too contrasty or washed out you got the value wrong - check your system -documentation! - -Many systems permit the system gamma to be changed via a lookup table in the -display driver, a few systems, including older Macs, change the response by -default. As of 1.5.4 three special values are available to handle common -situations: - - PNG_DEFAULT_sRGB: Indicates that the system conforms to the - IEC 61966-2-1 standard. This matches almost - all systems. - PNG_GAMMA_MAC_18: Indicates that the system is an older - (pre Mac OS 10.6) Apple Macintosh system with - the default settings. - PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates - that the system expects data with no gamma - encoding. - -You would use the linear (unencoded) value if you need to process the pixel -values further because this avoids the need to decode and re-encode each -component value whenever arithmetic is performed. A lot of graphics software -uses linear values for this reason, often with higher precision component values -to preserve overall accuracy. - - -The output_gamma value expresses how to decode the output values, not how -they are encoded. The values used correspond to the normal numbers used to -describe the overall gamma of a computer display system; for example 2.2 for -an sRGB conformant system. The values are scaled by 100000 in the _fixed -version of the API (so 220000 for sRGB.) - -The inverse of the value is always used to provide a default for the PNG file -encoding if it has no gAMA chunk and if png_set_gamma() has not been called -to override the PNG gamma information. - -When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode -opaque pixels however pixels with lower alpha values are not encoded, -regardless of the output gamma setting. - -When the standard Porter Duff handling is requested with mode 1 the output -encoding is set to be linear and the output_gamma value is only relevant -as a default for input data that has no gamma information. The linear output -encoding will be overridden if png_set_gamma() is called - the results may be -highly unexpected! - -The following numbers are derived from the sRGB standard and the research -behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of -0.45455 (1/2.2) for PNG. The value implicitly includes any viewing -correction required to take account of any differences in the color -environment of the original scene and the intended display environment; the -value expresses how to *decode* the image for display, not how the original -data was *encoded*. - -sRGB provides a peg for the PNG standard by defining a viewing environment. -sRGB itself, and earlier TV standards, actually use a more complex transform -(a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is -limited to simple power laws.) By saying that an image for direct display on -an sRGB conformant system should be stored with a gAMA chunk value of 45455 -(11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification -makes it possible to derive values for other display systems and -environments. - -The Mac value is deduced from the sRGB based on an assumption that the actual -extra viewing correction used in early Mac display systems was implemented as -a power 1.45 lookup table. - -Any system where a programmable lookup table is used or where the behavior of -the final display device characteristics can be changed requires system -specific code to obtain the current characteristic. However this can be -difficult and most PNG gamma correction only requires an approximate value. - -By default, if png_set_alpha_mode() is not called, libpng assumes that all -values are unencoded, linear, values and that the output device also has a -linear characteristic. This is only very rarely correct - it is invariably -better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the -default if you don't know what the right answer is! - -The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS -10.6) which used a correction table to implement a somewhat lower gamma on an -otherwise sRGB system. - -Both these values are reserved (not simple gamma values) in order to allow -more precise correction internally in the future. - -NOTE: the values can be passed to either the fixed or floating -point APIs, but the floating point API will also accept floating point -values. - -The second thing you may need to tell libpng about is how your system handles -alpha channel information. Some, but not all, PNG files contain an alpha -channel. To display these files correctly you need to compose the data onto a -suitable background, as described in the PNG specification. - -Libpng only supports composing onto a single color (using png_set_background; -see below). Otherwise you must do the composition yourself and, in this case, -you may need to call png_set_alpha_mode: - - #if PNG_LIBPNG_VER >= 10504 - png_set_alpha_mode(png_ptr, mode, screen_gamma); - #else - png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma); - #endif - -The screen_gamma value is the same as the argument to png_set_gamma; however, -how it affects the output depends on the mode. png_set_alpha_mode() sets the -file gamma default to 1/screen_gamma, so normally you don't need to call -png_set_gamma. If you need different defaults call png_set_gamma() before -png_set_alpha_mode() - if you call it after it will override the settings made -by png_set_alpha_mode(). - -The mode is as follows: - - PNG_ALPHA_PNG: The data is encoded according to the PNG -specification. Red, green and blue, or gray, components are -gamma encoded color values and are not premultiplied by the -alpha value. The alpha value is a linear measure of the -contribution of the pixel to the corresponding final output pixel. - -You should normally use this format if you intend to perform -color correction on the color values; most, maybe all, color -correction software has no handling for the alpha channel and, -anyway, the math to handle pre-multiplied component values is -unnecessarily complex. - -Before you do any arithmetic on the component values you need -to remove the gamma encoding and multiply out the alpha -channel. See the PNG specification for more detail. It is -important to note that when an image with an alpha channel is -scaled, linear encoded, pre-multiplied component values must -be used! - -The remaining modes assume you don't need to do any further color correction or -that if you do, your color correction software knows all about alpha (it -probably doesn't!). They 'associate' the alpha with the color information by -storing color channel values that have been scaled by the alpha. The -advantage is that the color channels can be resampled (the image can be -scaled) in this form. The disadvantage is that normal practice is to store -linear, not (gamma) encoded, values and this requires 16-bit channels for -still images rather than the 8-bit channels that are just about sufficient if -gamma encoding is used. In addition all non-transparent pixel values, -including completely opaque ones, must be gamma encoded to produce the final -image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes -described below (the latter being the two common names for associated alpha -color channels). Note that PNG files always contain non-associated color -channels; png_set_alpha_mode() with one of the modes causes the decoder to -convert the pixels to an associated form before returning them to your -application. - -Since it is not necessary to perform arithmetic on opaque color values so -long as they are not to be resampled and are in the final color space it is -possible to optimize the handling of alpha by storing the opaque pixels in -the PNG format (adjusted for the output color space) while storing partially -opaque pixels in the standard, linear, format. The accuracy required for -standard alpha composition is relatively low, because the pixels are -isolated, therefore typically the accuracy loss in storing 8-bit linear -values is acceptable. (This is not true if the alpha channel is used to -simulate transparency over large areas - use 16 bits or the PNG mode in -this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is -treated as opaque only if the alpha value is equal to the maximum value. - - PNG_ALPHA_STANDARD: The data libpng produces is encoded in the -standard way assumed by most correctly written graphics software. -The gamma encoding will be removed by libpng and the -linear component values will be pre-multiplied by the -alpha channel. - -With this format the final image must be re-encoded to -match the display gamma before the image is displayed. -If your system doesn't do that, yet still seems to -perform arithmetic on the pixels without decoding them, -it is broken - check out the modes below. - -With PNG_ALPHA_STANDARD libpng always produces linear -component values, whatever screen_gamma you supply. The -screen_gamma value is, however, used as a default for -the file gamma if the PNG file has no gamma information. - -If you call png_set_gamma() after png_set_alpha_mode() you -will override the linear encoding. Instead the -pre-multiplied pixel values will be gamma encoded but -the alpha channel will still be linear. This may -actually match the requirements of some broken software, -but it is unlikely. - -While linear 8-bit data is often used it has -insufficient precision for any image with a reasonable -dynamic range. To avoid problems, and if your software -supports it, use png_set_expand_16() to force all -components to 16 bits. - - PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD -except that completely opaque pixels are gamma encoded according to -the screen_gamma value. Pixels with alpha less than 1.0 -will still have linear components. - -Use this format if you have control over your -compositing software and so don't do other arithmetic -(such as scaling) on the data you get from libpng. Your -compositing software can simply copy opaque pixels to -the output but still has linear values for the -non-opaque pixels. - -In normal compositing, where the alpha channel encodes -partial pixel coverage (as opposed to broad area -translucency), the inaccuracies of the 8-bit -representation of non-opaque pixels are irrelevant. - -You can also try this format if your software is broken; -it might look better. - - PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD; however, all component -values, including the alpha channel are gamma encoded. This is -broken because, in practice, no implementation that uses this choice -correctly undoes the encoding before handling alpha composition. Use this -choice only if other serious errors in the software or hardware you use -mandate it. In most cases of broken software or hardware the bug in the -final display manifests as a subtle halo around composited parts of the -image. You may not even perceive this as a halo; the composited part of -the image may simply appear separate from the background, as though it had -been cut out of paper and pasted on afterward. - -If you don't have to deal with bugs in software or hardware, or if you can fix -them, there are three recommended ways of using png_set_alpha_mode(): - - png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG, - screen_gamma); - -You can do color correction on the result (libpng does not currently -support color correction internally). When you handle the alpha channel -you need to undo the gamma encoding and multiply out the alpha. - - png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD, - screen_gamma); - png_set_expand_16(png_ptr); - -If you are using the high level interface, don't call png_set_expand_16(); -instead pass PNG_TRANSFORM_EXPAND_16 to the interface. - -With this mode you can't do color correction, but you can do arithmetic, -including composition and scaling, on the data without further processing. - - png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED, - screen_gamma); - -You can avoid the expansion to 16-bit components with this mode, but you -lose the ability to scale the image or perform other linear arithmetic. -All you can do is compose the result onto a matching output. Since this -mode is libpng-specific you also need to write your own composition -software. - -The following are examples of calls to png_set_alpha_mode to achieve the -required overall gamma correction and, where necessary, alpha -premultiplication. - - png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); - -This is the default libpng handling of the alpha channel - it is not -pre-multiplied into the color components. In addition the call states -that the output is for a sRGB system and causes all PNG files without gAMA -chunks to be assumed to be encoded using sRGB. - - png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); - -In this case the output is assumed to be something like an sRGB conformant -display preceeded by a power-law lookup table of power 1.45. This is how -early Mac systems behaved. - - png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); - -This is the classic Jim Blinn approach and will work in academic -environments where everything is done by the book. It has the shortcoming -of assuming that input PNG data with no gamma information is linear - this -is unlikely to be correct unless the PNG files where generated locally. -Most of the time the output precision will be so low as to show -significant banding in dark areas of the image. - - png_set_expand_16(pp); - png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); - -This is a somewhat more realistic Jim Blinn inspired approach. PNG files -are assumed to have the sRGB encoding if not marked with a gamma value and -the output is always 16 bits per component. This permits accurate scaling -and processing of the data. If you know that your input PNG files were -generated locally you might need to replace PNG_DEFAULT_sRGB with the -correct value for your system. - - png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); - -If you just need to composite the PNG image onto an existing background -and if you control the code that does this you can use the optimization -setting. In this case you just copy completely opaque pixels to the -output. For pixels that are not completely transparent (you just skip -those) you do the composition math using png_composite or png_composite_16 -below then encode the resultant 8-bit or 16-bit values to match the output -encoding. - - Other cases - -If neither the PNG nor the standard linear encoding work for you because -of the software or hardware you use then you have a big problem. The PNG -case will probably result in halos around the image. The linear encoding -will probably result in a washed out, too bright, image (it's actually too -contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably -substantially reduce the halos. Alternatively try: - - png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); - -This option will also reduce the halos, but there will be slight dark -halos round the opaque parts of the image where the background is light. -In the OPTIMIZED mode the halos will be light halos where the background -is dark. Take your pick - the halos are unavoidable unless you can get -your hardware/software fixed! (The OPTIMIZED approach is slightly -faster.) - -When the default gamma of PNG files doesn't match the output gamma. -If you have PNG files with no gamma information png_set_alpha_mode allows -you to provide a default gamma, but it also sets the ouput gamma to the -matching value. If you know your PNG files have a gamma that doesn't -match the output you can take advantage of the fact that -png_set_alpha_mode always sets the output gamma but only sets the PNG -default if it is not already set: - - png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); - png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); - -The first call sets both the default and the output gamma values, the -second call overrides the output gamma without changing the default. This -is easier than achieving the same effect with png_set_gamma. You must use -PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will -fire if more than one call to png_set_alpha_mode and png_set_background is -made in the same read operation, however multiple calls with PNG_ALPHA_PNG -are ignored. - -If you don't need, or can't handle, the alpha channel you can call -png_set_background() to remove it by compositing against a fixed color. Don't -call png_set_strip_alpha() to do this - it will leave spurious pixel values in -transparent parts of this image. - - png_set_background(png_ptr, &background_color, - PNG_BACKGROUND_GAMMA_SCREEN, 0, 1); - -The background_color is an RGB or grayscale value according to the data format -libpng will produce for you. Because you don't yet know the format of the PNG -file, if you call png_set_background at this point you must arrange for the -format produced by libpng to always have 8-bit or 16-bit components and then -store the color as an 8-bit or 16-bit color as appropriate. The color contains -separate gray and RGB component values, so you can let libpng produce gray or -RGB output according to the input format, but low bit depth grayscale images -must always be converted to at least 8-bit format. (Even though low bit depth -grayscale images can't have an alpha channel they can have a transparent -color!) - -You set the transforms you need later, either as flags to the high level -interface or libpng API calls for the low level interface. For reference the -settings and API calls required are: - -8-bit values: - PNG_TRANSFORM_SCALE_16 | PNG_EXPAND - png_set_expand(png_ptr); png_set_scale_16(png_ptr); - - If you must get exactly the same inaccurate results - produced by default in versions prior to libpng-1.5.4, - use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr) - instead. - -16-bit values: - PNG_TRANSFORM_EXPAND_16 - png_set_expand_16(png_ptr); - -In either case palette image data will be expanded to RGB. If you just want -color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr) -to the list. - -Calling png_set_background before the PNG file header is read will not work -prior to libpng-1.5.4. Because the failure may result in unexpected warnings or -errors it is therefore much safer to call png_set_background after the head has -been read. Unfortunately this means that prior to libpng-1.5.4 it cannot be -used with the high level interface. - -The high-level read interface - -At this point there are two ways to proceed; through the high-level -read interface, or through a sequence of low-level read operations. -You can use the high-level interface if (a) you are willing to read -the entire image into memory, and (b) the input transformations -you want to do are limited to the following set: - - PNG_TRANSFORM_IDENTITY No transformation - PNG_TRANSFORM_SCALE_16 Strip 16-bit samples to - 8-bit accurately - PNG_TRANSFORM_STRIP_16 Chop 16-bit samples to - 8-bit less accurately - PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel - PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit - samples to bytes - PNG_TRANSFORM_PACKSWAP Change order of packed - pixels to LSB first - PNG_TRANSFORM_EXPAND Perform set_expand() - PNG_TRANSFORM_INVERT_MONO Invert monochrome images - PNG_TRANSFORM_SHIFT Normalize pixels to the - sBIT depth - PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA - to BGRA - PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA - to AG - PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity - to transparency - PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples - PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples - to RGB (or GA to RGBA) - PNG_TRANSFORM_EXPAND_16 Expand samples to 16 bits - -(This excludes setting a background color, doing gamma transformation, -quantizing, and setting filler.) If this is the case, simply do this: - - png_read_png(png_ptr, info_ptr, png_transforms, NULL) - -where png_transforms is an integer containing the bitwise OR of some -set of transformation flags. This call is equivalent to png_read_info(), -followed the set of transformations indicated by the transform mask, -then png_read_image(), and finally png_read_end(). - -(The final parameter of this call is not yet used. Someday it might point -to transformation parameters required by some future input transform.) - -You must use png_transforms and not call any png_set_transform() functions -when you use png_read_png(). - -After you have called png_read_png(), you can retrieve the image data -with - - row_pointers = png_get_rows(png_ptr, info_ptr); - -where row_pointers is an array of pointers to the pixel data for each row: - - png_bytep row_pointers[height]; - -If you know your image size and pixel size ahead of time, you can allocate -row_pointers prior to calling png_read_png() with - - if (height > PNG_UINT_32_MAX/(sizeof (png_byte))) - png_error (png_ptr, - "Image is too tall to process in memory"); - - if (width > PNG_UINT_32_MAX/pixel_size) - png_error (png_ptr, - "Image is too wide to process in memory"); - - row_pointers = png_malloc(png_ptr, - height*(sizeof (png_bytep))); - - for (int i=0; i<height, i++) - row_pointers[i]=NULL; /* security precaution */ - - for (int i=0; i<height, i++) - row_pointers[i]=png_malloc(png_ptr, - width*pixel_size); - - png_set_rows(png_ptr, info_ptr, &row_pointers); - -Alternatively you could allocate your image in one big block and define -row_pointers[i] to point into the proper places in your block. - -If you use png_set_rows(), the application is responsible for freeing -row_pointers (and row_pointers[i], if they were separately allocated). - -If you don't allocate row_pointers ahead of time, png_read_png() will -do it, and it'll be free'ed by libpng when you call png_destroy_*(). - -The low-level read interface - -If you are going the low-level route, you are now ready to read all -the file information up to the actual image data. You do this with a -call to png_read_info(). - - png_read_info(png_ptr, info_ptr); - -This will process all chunks up to but not including the image data. - -This also copies some of the data from the PNG file into the decode structure -for use in later transformations. Important information copied in is: - -1) The PNG file gamma from the gAMA chunk. This overwrites the default value -provided by an earlier call to png_set_gamma or png_set_alpha_mode. - -2) Prior to libpng-1.5.4 the background color from a bKGd chunk. This -damages the information provided by an earlier call to png_set_background -resulting in unexpected behavior. Libpng-1.5.4 no longer does this. - -3) The number of significant bits in each component value. Libpng uses this to -optimize gamma handling by reducing the internal lookup table sizes. - -4) The transparent color information from a tRNS chunk. This can be modified by -a later call to png_set_tRNS. - -Querying the info structure - -Functions are used to get the information from the info_ptr once it -has been read. Note that these fields may not be completely filled -in until png_read_end() has read the chunk data following the image. - - png_get_IHDR(png_ptr, info_ptr, &width, &height, - &bit_depth, &color_type, &interlace_type, - &compression_type, &filter_method); - - width - holds the width of the image - in pixels (up to 2^31). - - height - holds the height of the image - in pixels (up to 2^31). - - bit_depth - holds the bit depth of one of the - image channels. (valid values are - 1, 2, 4, 8, 16 and depend also on - the color_type. See also - significant bits (sBIT) below). - - color_type - describes which color/alpha channels - are present. - PNG_COLOR_TYPE_GRAY - (bit depths 1, 2, 4, 8, 16) - PNG_COLOR_TYPE_GRAY_ALPHA - (bit depths 8, 16) - PNG_COLOR_TYPE_PALETTE - (bit depths 1, 2, 4, 8) - PNG_COLOR_TYPE_RGB - (bit_depths 8, 16) - PNG_COLOR_TYPE_RGB_ALPHA - (bit_depths 8, 16) - - PNG_COLOR_MASK_PALETTE - PNG_COLOR_MASK_COLOR - PNG_COLOR_MASK_ALPHA - - interlace_type - (PNG_INTERLACE_NONE or - PNG_INTERLACE_ADAM7) - - compression_type - (must be PNG_COMPRESSION_TYPE_BASE - for PNG 1.0) - - filter_method - (must be PNG_FILTER_TYPE_BASE - for PNG 1.0, and can also be - PNG_INTRAPIXEL_DIFFERENCING if - the PNG datastream is embedded in - a MNG-1.0 datastream) - - Any of width, height, color_type, bit_depth, - interlace_type, compression_type, or filter_method can - be NULL if you are not interested in their values. - - Note that png_get_IHDR() returns 32-bit data into - the application's width and height variables. - This is an unsafe situation if these are not png_uint_32 - variables. In such situations, the - png_get_image_width() and png_get_image_height() - functions described below are safer. - - width = png_get_image_width(png_ptr, - info_ptr); - - height = png_get_image_height(png_ptr, - info_ptr); - - bit_depth = png_get_bit_depth(png_ptr, - info_ptr); - - color_type = png_get_color_type(png_ptr, - info_ptr); - - interlace_type = png_get_interlace_type(png_ptr, - info_ptr); - - compression_type = png_get_compression_type(png_ptr, - info_ptr); - - filter_method = png_get_filter_type(png_ptr, - info_ptr); - - channels = png_get_channels(png_ptr, info_ptr); - - channels - number of channels of info for the - color type (valid values are 1 (GRAY, - PALETTE), 2 (GRAY_ALPHA), 3 (RGB), - 4 (RGB_ALPHA or RGB + filler byte)) - - rowbytes = png_get_rowbytes(png_ptr, info_ptr); - - rowbytes - number of bytes needed to hold a row - - signature = png_get_signature(png_ptr, info_ptr); - - signature - holds the signature read from the - file (if any). The data is kept in - the same offset it would be if the - whole signature were read (i.e. if an - application had already read in 4 - bytes of signature before starting - libpng, the remaining 4 bytes would - be in signature[4] through signature[7] - (see png_set_sig_bytes())). - -These are also important, but their validity depends on whether the chunk -has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and -png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the -data has been read, or zero if it is missing. The parameters to the -png_get_<chunk> are set directly if they are simple data types, or a -pointer into the info_ptr is returned for any complex types. - -The colorspace data from gAMA, cHRM, sRGB, iCCP, and sBIT chunks -is simply returned to give the application information about how the -image was encoded. Libpng itself only does transformations using the file -gamma when combining semitransparent pixels with the background color, and, -since libpng-1.6.0, when converting between 8-bit sRGB and 16-bit linear pixels -within the simplified API. Libpng also uses the file gamma when converting -RGB to gray, beginning with libpng-1.0.5, if the application calls -png_set_rgb_to_gray()). - - png_get_PLTE(png_ptr, info_ptr, &palette, - &num_palette); - - palette - the palette for the file - (array of png_color) - - num_palette - number of entries in the palette - - png_get_gAMA(png_ptr, info_ptr, &file_gamma); - png_get_gAMA_fixed(png_ptr, info_ptr, &int_file_gamma); - - file_gamma - the gamma at which the file is - written (PNG_INFO_gAMA) - - int_file_gamma - 100,000 times the gamma at which the - file is written - - png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x, - &red_y, &green_x, &green_y, &blue_x, &blue_y) - png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, - &green_X, &green_Y, &green_Z, &blue_X, &blue_Y, - &blue_Z) - png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, - &int_white_y, &int_red_x, &int_red_y, - &int_green_x, &int_green_y, &int_blue_x, - &int_blue_y) - png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y, - &int_red_Z, &int_green_X, &int_green_Y, - &int_green_Z, &int_blue_X, &int_blue_Y, - &int_blue_Z) - - {white,red,green,blue}_{x,y} - A color space encoding specified using the - chromaticities of the end points and the - white point. (PNG_INFO_cHRM) - - {red,green,blue}_{X,Y,Z} - A color space encoding specified using the - encoding end points - the CIE tristimulus - specification of the intended color of the red, - green and blue channels in the PNG RGB data. - The white point is simply the sum of the three - end points. (PNG_INFO_cHRM) - - png_get_sRGB(png_ptr, info_ptr, &srgb_intent); - - srgb_intent - the rendering intent (PNG_INFO_sRGB) - The presence of the sRGB chunk - means that the pixel data is in the - sRGB color space. This chunk also - implies specific values of gAMA and - cHRM. - - png_get_iCCP(png_ptr, info_ptr, &name, - &compression_type, &profile, &proflen); - - name - The profile name. - - compression_type - The compression type; always - PNG_COMPRESSION_TYPE_BASE for PNG 1.0. - You may give NULL to this argument to - ignore it. - - profile - International Color Consortium color - profile data. May contain NULs. - - proflen - length of profile data in bytes. - - png_get_sBIT(png_ptr, info_ptr, &sig_bit); - - sig_bit - the number of significant bits for - (PNG_INFO_sBIT) each of the gray, - red, green, and blue channels, - whichever are appropriate for the - given color type (png_color_16) - - png_get_tRNS(png_ptr, info_ptr, &trans_alpha, - &num_trans, &trans_color); - - trans_alpha - array of alpha (transparency) - entries for palette (PNG_INFO_tRNS) - - num_trans - number of transparent entries - (PNG_INFO_tRNS) - - trans_color - graylevel or color sample values of - the single transparent color for - non-paletted images (PNG_INFO_tRNS) - - png_get_hIST(png_ptr, info_ptr, &hist); - (PNG_INFO_hIST) - - hist - histogram of palette (array of - png_uint_16) - - png_get_tIME(png_ptr, info_ptr, &mod_time); - - mod_time - time image was last modified - (PNG_VALID_tIME) - - png_get_bKGD(png_ptr, info_ptr, &background); - - background - background color (of type - png_color_16p) (PNG_VALID_bKGD) - valid 16-bit red, green and blue - values, regardless of color_type - - num_comments = png_get_text(png_ptr, info_ptr, - &text_ptr, &num_text); - - num_comments - number of comments - - text_ptr - array of png_text holding image - comments - - text_ptr[i].compression - type of compression used - on "text" PNG_TEXT_COMPRESSION_NONE - PNG_TEXT_COMPRESSION_zTXt - PNG_ITXT_COMPRESSION_NONE - PNG_ITXT_COMPRESSION_zTXt - - text_ptr[i].key - keyword for comment. Must contain - 1-79 characters. - - text_ptr[i].text - text comments for current - keyword. Can be empty. - - text_ptr[i].text_length - length of text string, - after decompression, 0 for iTXt - - text_ptr[i].itxt_length - length of itxt string, - after decompression, 0 for tEXt/zTXt - - text_ptr[i].lang - language of comment (empty - string for unknown). - - text_ptr[i].lang_key - keyword in UTF-8 - (empty string for unknown). - - Note that the itxt_length, lang, and lang_key - members of the text_ptr structure only exist when the - library is built with iTXt chunk support. Prior to - libpng-1.4.0 the library was built by default without - iTXt support. Also note that when iTXt is supported, - they contain NULL pointers when the "compression" - field contains PNG_TEXT_COMPRESSION_NONE or - PNG_TEXT_COMPRESSION_zTXt. - - num_text - number of comments (same as - num_comments; you can put NULL here - to avoid the duplication) - - Note while png_set_text() will accept text, language, - and translated keywords that can be NULL pointers, the - structure returned by png_get_text will always contain - regular zero-terminated C strings. They might be - empty strings but they will never be NULL pointers. - - num_spalettes = png_get_sPLT(png_ptr, info_ptr, - &palette_ptr); - - num_spalettes - number of sPLT chunks read. - - palette_ptr - array of palette structures holding - contents of one or more sPLT chunks - read. - - png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, - &unit_type); - - offset_x - positive offset from the left edge - of the screen (can be negative) - - offset_y - positive offset from the top edge - of the screen (can be negative) - - unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER - - png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, - &unit_type); - - res_x - pixels/unit physical resolution in - x direction - - res_y - pixels/unit physical resolution in - x direction - - unit_type - PNG_RESOLUTION_UNKNOWN, - PNG_RESOLUTION_METER - - png_get_sCAL(png_ptr, info_ptr, &unit, &width, - &height) - - unit - physical scale units (an integer) - - width - width of a pixel in physical scale units - - height - height of a pixel in physical scale units - (width and height are doubles) - - png_get_sCAL_s(png_ptr, info_ptr, &unit, &width, - &height) - - unit - physical scale units (an integer) - - width - width of a pixel in physical scale units - (expressed as a string) - - height - height of a pixel in physical scale units - (width and height are strings like "2.54") - - num_unknown_chunks = png_get_unknown_chunks(png_ptr, - info_ptr, &unknowns) - - unknowns - array of png_unknown_chunk - structures holding unknown chunks - - unknowns[i].name - name of unknown chunk - - unknowns[i].data - data of unknown chunk - - unknowns[i].size - size of unknown chunk's data - - unknowns[i].location - position of chunk in file - - The value of "i" corresponds to the order in which the - chunks were read from the PNG file or inserted with the - png_set_unknown_chunks() function. - - The value of "location" is a bitwise "or" of - - PNG_HAVE_IHDR (0x01) - PNG_HAVE_PLTE (0x02) - PNG_AFTER_IDAT (0x08) - -The data from the pHYs chunk can be retrieved in several convenient -forms: - - res_x = png_get_x_pixels_per_meter(png_ptr, - info_ptr) - - res_y = png_get_y_pixels_per_meter(png_ptr, - info_ptr) - - res_x_and_y = png_get_pixels_per_meter(png_ptr, - info_ptr) - - res_x = png_get_x_pixels_per_inch(png_ptr, - info_ptr) - - res_y = png_get_y_pixels_per_inch(png_ptr, - info_ptr) - - res_x_and_y = png_get_pixels_per_inch(png_ptr, - info_ptr) - - aspect_ratio = png_get_pixel_aspect_ratio(png_ptr, - info_ptr) - - Each of these returns 0 [signifying "unknown"] if - the data is not present or if res_x is 0; - res_x_and_y is 0 if res_x != res_y - - Note that because of the way the resolutions are - stored internally, the inch conversions won't - come out to exactly even number. For example, - 72 dpi is stored as 0.28346 pixels/meter, and - when this is retrieved it is 71.9988 dpi, so - be sure to round the returned value appropriately - if you want to display a reasonable-looking result. - -The data from the oFFs chunk can be retrieved in several convenient -forms: - - x_offset = png_get_x_offset_microns(png_ptr, info_ptr); - - y_offset = png_get_y_offset_microns(png_ptr, info_ptr); - - x_offset = png_get_x_offset_inches(png_ptr, info_ptr); - - y_offset = png_get_y_offset_inches(png_ptr, info_ptr); - - Each of these returns 0 [signifying "unknown" if both - x and y are 0] if the data is not present or if the - chunk is present but the unit is the pixel. The - remark about inexact inch conversions applies here - as well, because a value in inches can't always be - converted to microns and back without some loss - of precision. - -For more information, see the -PNG specification for chunk contents. Be careful with trusting -rowbytes, as some of the transformations could increase the space -needed to hold a row (expand, filler, gray_to_rgb, etc.). -See png_read_update_info(), below. - -A quick word about text_ptr and num_text. PNG stores comments in -keyword/text pairs, one pair per chunk, with no limit on the number -of text chunks, and a 2^31 byte limit on their size. While there are -suggested keywords, there is no requirement to restrict the use to these -strings. It is strongly suggested that keywords and text be sensible -to humans (that's the point), so don't use abbreviations. Non-printing -symbols are not allowed. See the PNG specification for more details. -There is also no requirement to have text after the keyword. - -Keywords should be limited to 79 Latin-1 characters without leading or -trailing spaces, but non-consecutive spaces are allowed within the -keyword. It is possible to have the same keyword any number of times. -The text_ptr is an array of png_text structures, each holding a -pointer to a language string, a pointer to a keyword and a pointer to -a text string. The text string, language code, and translated -keyword may be empty or NULL pointers. The keyword/text -pairs are put into the array in the order that they are received. -However, some or all of the text chunks may be after the image, so, to -make sure you have read all the text chunks, don't mess with these -until after you read the stuff after the image. This will be -mentioned again below in the discussion that goes with png_read_end(). - -Input transformations - -After you've read the header information, you can set up the library -to handle any special transformations of the image data. The various -ways to transform the data will be described in the order that they -should occur. This is important, as some of these change the color -type and/or bit depth of the data, and some others only work on -certain color types and bit depths. - -Transformations you request are ignored if they don't have any meaning for a -particular input data format. However some transformations can have an effect -as a result of a previous transformation. If you specify a contradictory set of -transformations, for example both adding and removing the alpha channel, you -cannot predict the final result. - -The color used for the transparency values should be supplied in the same -format/depth as the current image data. It is stored in the same format/depth -as the image data in a tRNS chunk, so this is what libpng expects for this data. - -The color used for the background value depends on the need_expand argument as -described below. - -Data will be decoded into the supplied row buffers packed into bytes -unless the library has been told to transform it into another format. -For example, 4 bit/pixel paletted or grayscale data will be returned -2 pixels/byte with the leftmost pixel in the high-order bits of the byte, -unless png_set_packing() is called. 8-bit RGB data will be stored -in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha() -is called to insert filler bytes, either before or after each RGB triplet. - -16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant -byte of the color value first, unless png_set_scale_16() is called to -transform it to regular RGB RGB triplets, or png_set_filler() or -png_set_add alpha() is called to insert two filler bytes, either before -or after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can -be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(), -or png_set_scale_16(). - -The following code transforms grayscale images of less than 8 to 8 bits, -changes paletted images to RGB, and adds a full alpha channel if there is -transparency information in a tRNS chunk. This is most useful on -grayscale images with bit depths of 2 or 4 or if there is a multiple-image -viewing application that wishes to treat all images in the same way. - - if (color_type == PNG_COLOR_TYPE_PALETTE) - png_set_palette_to_rgb(png_ptr); - - if (png_get_valid(png_ptr, info_ptr, - PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr); - - if (color_type == PNG_COLOR_TYPE_GRAY && - bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); - -The first two functions are actually aliases for png_set_expand(), added -in libpng version 1.0.4, with the function names expanded to improve code -readability. In some future version they may actually do different -things. - -As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was -added. It expands the sample depth without changing tRNS to alpha. - -As of libpng version 1.5.2, png_set_expand_16() was added. It behaves as -png_set_expand(); however, the resultant channels have 16 bits rather than 8. -Use this when the output color or gray channels are made linear to avoid fairly -severe accuracy loss. - - if (bit_depth < 16) - png_set_expand_16(png_ptr); - -PNG can have files with 16 bits per channel. If you only can handle -8 bits per channel, this will strip the pixels down to 8-bit. - - if (bit_depth == 16) -#if PNG_LIBPNG_VER >= 10504 - png_set_scale_16(png_ptr); -#else - png_set_strip_16(png_ptr); -#endif - -(The more accurate "png_set_scale_16()" API became available in libpng version -1.5.4). - -If you need to process the alpha channel on the image separately from the image -data (for example if you convert it to a bitmap mask) it is possible to have -libpng strip the channel leaving just RGB or gray data: - - if (color_type & PNG_COLOR_MASK_ALPHA) - png_set_strip_alpha(png_ptr); - -If you strip the alpha channel you need to find some other way of dealing with -the information. If, instead, you want to convert the image to an opaque -version with no alpha channel use png_set_background; see below. - -As of libpng version 1.5.2, almost all useful expansions are supported, the -major ommissions are conversion of grayscale to indexed images (which can be -done trivially in the application) and conversion of indexed to grayscale (which -can be done by a trivial manipulation of the palette.) - -In the following table, the 01 means grayscale with depth<8, 31 means -indexed with depth<8, other numerals represent the color type, "T" means -the tRNS chunk is present, A means an alpha channel is present, and O -means tRNS or alpha is present but all pixels in the image are opaque. - - FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O - TO - 01 - [G] - - - - - - - - - - - - - - 31 [Q] Q [Q] [Q] [Q] Q Q Q Q Q Q [Q] [Q] Q Q - 0 1 G + . . G G G G G G B B GB GB - 0T lt Gt t + . Gt G G Gt G G Bt Bt GBt GBt - 0O lt Gt t . + Gt Gt G Gt Gt G Bt Bt GBt GBt - 2 C P C C C + . . C - - CB CB B B - 2T Ct - Ct C C t + t - - - CBt CBt Bt Bt - 2O Ct - Ct C C t t + - - - CBt CBt Bt Bt - 3 [Q] p [Q] [Q] [Q] Q Q Q + . . [Q] [Q] Q Q - 3T [Qt] p [Qt][Q] [Q] Qt Qt Qt t + t [Qt][Qt] Qt Qt - 3O [Qt] p [Qt][Q] [Q] Qt Qt Qt t t + [Qt][Qt] Qt Qt - 4A lA G A T T GA GT GT GA GT GT + BA G GBA - 4O lA GBA A T T GA GT GT GA GT GT BA + GBA G - 6A CA PA CA C C A T tT PA P P C CBA + BA - 6O CA PBA CA C C A tT T PA P P CBA C BA + - -Within the matrix, - "+" identifies entries where 'from' and 'to' are the same. - "-" means the transformation is not supported. - "." means nothing is necessary (a tRNS chunk can just be ignored). - "t" means the transformation is obtained by png_set_tRNS. - "A" means the transformation is obtained by png_set_add_alpha(). - "X" means the transformation is obtained by png_set_expand(). - "1" means the transformation is obtained by - png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() - if there is no transparency in the original or the final - format). - "C" means the transformation is obtained by png_set_gray_to_rgb(). - "G" means the transformation is obtained by png_set_rgb_to_gray(). - "P" means the transformation is obtained by - png_set_expand_palette_to_rgb(). - "p" means the transformation is obtained by png_set_packing(). - "Q" means the transformation is obtained by png_set_quantize(). - "T" means the transformation is obtained by - png_set_tRNS_to_alpha(). - "B" means the transformation is obtained by - png_set_background(), or png_strip_alpha(). - -When an entry has multiple transforms listed all are required to cause the -right overall transformation. When two transforms are separated by a comma -either will do the job. When transforms are enclosed in [] the transform should -do the job but this is currently unimplemented - a different format will result -if the suggested transformations are used. - -In PNG files, the alpha channel in an image -is the level of opacity. If you need the alpha channel in an image to -be the level of transparency instead of opacity, you can invert the -alpha channel (or the tRNS chunk data) after it's read, so that 0 is -fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit -images) is fully transparent, with - - png_set_invert_alpha(png_ptr); - -PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as -they can, resulting in, for example, 8 pixels per byte for 1 bit -files. This code expands to 1 pixel per byte without changing the -values of the pixels: - - if (bit_depth < 8) - png_set_packing(png_ptr); - -PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels -stored in a PNG image have been "scaled" or "shifted" up to the next -higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] -to 8 bits/sample in the range [0, 255]). However, it is also possible -to convert the PNG pixel data back to the original bit depth of the -image. This call reduces the pixels back down to the original bit depth: - - png_color_8p sig_bit; - - if (png_get_sBIT(png_ptr, info_ptr, &sig_bit)) - png_set_shift(png_ptr, sig_bit); - -PNG files store 3-color pixels in red, green, blue order. This code -changes the storage of the pixels to blue, green, red: - - if (color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_RGB_ALPHA) - png_set_bgr(png_ptr); - -PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them -into 4 or 8 bytes for windowing systems that need them in this format: - - if (color_type == PNG_COLOR_TYPE_RGB) - png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE); - -where "filler" is the 8-bit or 16-bit number to fill with, and the location -is either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether -you want the filler before the RGB or after. When filling an 8-bit pixel, -the least significant 8 bits of the number are used, if a 16-bit number is -supplied. This transformation does not affect images that already have full -alpha channels. To add an opaque alpha channel, use filler=0xffff and -PNG_FILLER_AFTER which will generate RGBA pixels. - -Note that png_set_filler() does not change the color type. If you want -to do that, you can add a true alpha channel with - - if (color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_GRAY) - png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER); - -where "filler" contains the alpha value to assign to each pixel. -The png_set_add_alpha() function was added in libpng-1.2.7. - -If you are reading an image with an alpha channel, and you need the -data as ARGB instead of the normal PNG format RGBA: - - if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) - png_set_swap_alpha(png_ptr); - -For some uses, you may want a grayscale image to be represented as -RGB. This code will do that conversion: - - if (color_type == PNG_COLOR_TYPE_GRAY || - color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - png_set_gray_to_rgb(png_ptr); - -Conversely, you can convert an RGB or RGBA image to grayscale or grayscale -with alpha. - - if (color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_RGB_ALPHA) - png_set_rgb_to_gray(png_ptr, error_action, - double red_weight, double green_weight); - - error_action = 1: silently do the conversion - - error_action = 2: issue a warning if the original - image has any pixel where - red != green or red != blue - - error_action = 3: issue an error and abort the - conversion if the original - image has any pixel where - red != green or red != blue - - red_weight: weight of red component - - green_weight: weight of green component - If either weight is negative, default - weights are used. - -In the corresponding fixed point API the red_weight and green_weight values are -simply scaled by 100,000: - - png_set_rgb_to_gray(png_ptr, error_action, - png_fixed_point red_weight, - png_fixed_point green_weight); - -If you have set error_action = 1 or 2, you can -later check whether the image really was gray, after processing -the image rows, with the png_get_rgb_to_gray_status(png_ptr) function. -It will return a png_byte that is zero if the image was gray or -1 if there were any non-gray pixels. Background and sBIT data -will be silently converted to grayscale, using the green channel -data for sBIT, regardless of the error_action setting. - -The default values come from the PNG file cHRM chunk if present; otherwise, the -defaults correspond to the ITU-R recommendation 709, and also the sRGB color -space, as recommended in the Charles Poynton's Colour FAQ, -Copyright (c) 2006-11-28 Charles Poynton, in section 9: - -<http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9> - - Y = 0.2126 * R + 0.7152 * G + 0.0722 * B - -Previous versions of this document, 1998 through 2002, recommended a slightly -different formula: - - Y = 0.212671 * R + 0.715160 * G + 0.072169 * B - -Libpng uses an integer approximation: - - Y = (6968 * R + 23434 * G + 2366 * B)/32768 - -The calculation is done in a linear colorspace, if the image gamma -can be determined. - -The png_set_background() function has been described already; it tells libpng to -composite images with alpha or simple transparency against the supplied -background color. For compatibility with versions of libpng earlier than -libpng-1.5.4 it is recommended that you call the function after reading the file -header, even if you don't want to use the color in a bKGD chunk, if one exists. - -If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), -you may use this color, or supply another color more suitable for -the current display (e.g., the background color from a web page). You -need to tell libpng how the color is represented, both the format of the -component values in the color (the number of bits) and the gamma encoding of the -color. The function takes two arguments, background_gamma_mode and need_expand -to convey this information; however, only two combinations are likely to be -useful: - - png_color_16 my_background; - png_color_16p image_background; - - if (png_get_bKGD(png_ptr, info_ptr, &image_background)) - png_set_background(png_ptr, image_background, - PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1); - else - png_set_background(png_ptr, &my_background, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1); - -The second call was described above - my_background is in the format of the -final, display, output produced by libpng. Because you now know the format of -the PNG it is possible to avoid the need to choose either 8-bit or 16-bit -output and to retain palette images (the palette colors will be modified -appropriately and the tRNS chunk removed.) However, if you are doing this, -take great care not to ask for transformations without checking first that -they apply! - -In the first call the background color has the original bit depth and color type -of the PNG file. So, for palette images the color is supplied as a palette -index and for low bit greyscale images the color is a reduced bit value in -image_background->gray. - -If you didn't call png_set_gamma() before reading the file header, for example -if you need your code to remain compatible with older versions of libpng prior -to libpng-1.5.4, this is the place to call it. - -Do not call it if you called png_set_alpha_mode(); doing so will damage the -settings put in place by png_set_alpha_mode(). (If png_set_alpha_mode() is -supported then you can certainly do png_set_gamma() before reading the PNG -header.) - -This API unconditionally sets the screen and file gamma values, so it will -override the value in the PNG file unless it is called before the PNG file -reading starts. For this reason you must always call it with the PNG file -value when you call it in this position: - - if (png_get_gAMA(png_ptr, info_ptr, &file_gamma)) - png_set_gamma(png_ptr, screen_gamma, file_gamma); - - else - png_set_gamma(png_ptr, screen_gamma, 0.45455); - -If you need to reduce an RGB file to a paletted file, or if a paletted -file has more entries than will fit on your screen, png_set_quantize() -will do that. Note that this is a simple match quantization that merely -finds the closest color available. This should work fairly well with -optimized palettes, but fairly badly with linear color cubes. If you -pass a palette that is larger than maximum_colors, the file will -reduce the number of colors in the palette so it will fit into -maximum_colors. If there is a histogram, libpng will use it to make -more intelligent choices when reducing the palette. If there is no -histogram, it may not do as good a job. - - if (color_type & PNG_COLOR_MASK_COLOR) - { - if (png_get_valid(png_ptr, info_ptr, - PNG_INFO_PLTE)) - { - png_uint_16p histogram = NULL; - - png_get_hIST(png_ptr, info_ptr, - &histogram); - png_set_quantize(png_ptr, palette, num_palette, - max_screen_colors, histogram, 1); - } - - else - { - png_color std_color_cube[MAX_SCREEN_COLORS] = - { ... colors ... }; - - png_set_quantize(png_ptr, std_color_cube, - MAX_SCREEN_COLORS, MAX_SCREEN_COLORS, - NULL,0); - } - } - -PNG files describe monochrome as black being zero and white being one. -The following code will reverse this (make black be one and white be -zero): - - if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY) - png_set_invert_mono(png_ptr); - -This function can also be used to invert grayscale and gray-alpha images: - - if (color_type == PNG_COLOR_TYPE_GRAY || - color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - png_set_invert_mono(png_ptr); - -PNG files store 16-bit pixels in network byte order (big-endian, -ie. most significant bits first). This code changes the storage to the -other way (little-endian, i.e. least significant bits first, the -way PCs store them): - - if (bit_depth == 16) - png_set_swap(png_ptr); - -If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you -need to change the order the pixels are packed into bytes, you can use: - - if (bit_depth < 8) - png_set_packswap(png_ptr); - -Finally, you can write your own transformation function if none of -the existing ones meets your needs. This is done by setting a callback -with - - png_set_read_user_transform_fn(png_ptr, - read_transform_fn); - -You must supply the function - - void read_transform_fn(png_structp png_ptr, png_row_infop - row_info, png_bytep data) - -See pngtest.c for a working example. Your function will be called -after all of the other transformations have been processed. Take care with -interlaced images if you do the interlace yourself - the width of the row is the -width in 'row_info', not the overall image width. - -If supported, libpng provides two information routines that you can use to find -where you are in processing the image: - - png_get_current_pass_number(png_structp png_ptr); - png_get_current_row_number(png_structp png_ptr); - -Don't try using these outside a transform callback - firstly they are only -supported if user transforms are supported, secondly they may well return -unexpected results unless the row is actually being processed at the moment they -are called. - -With interlaced -images the value returned is the row in the input sub-image image. Use -PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to -find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass). - -The discussion of interlace handling above contains more information on how to -use these values. - -You can also set up a pointer to a user structure for use by your -callback function, and you can inform libpng that your transform -function will change the number of channels or bit depth with the -function - - png_set_user_transform_info(png_ptr, user_ptr, - user_depth, user_channels); - -The user's application, not libpng, is responsible for allocating and -freeing any memory required for the user structure. - -You can retrieve the pointer via the function -png_get_user_transform_ptr(). For example: - - voidp read_user_transform_ptr = - png_get_user_transform_ptr(png_ptr); - -The last thing to handle is interlacing; this is covered in detail below, -but you must call the function here if you want libpng to handle expansion -of the interlaced image. - - number_of_passes = png_set_interlace_handling(png_ptr); - -After setting the transformations, libpng can update your png_info -structure to reflect any transformations you've requested with this -call. - - png_read_update_info(png_ptr, info_ptr); - -This is most useful to update the info structure's rowbytes -field so you can use it to allocate your image memory. This function -will also update your palette with the correct screen_gamma and -background if these have been given with the calls above. You may -only call png_read_update_info() once with a particular info_ptr. - -After you call png_read_update_info(), you can allocate any -memory you need to hold the image. The row data is simply -raw byte data for all forms of images. As the actual allocation -varies among applications, no example will be given. If you -are allocating one large chunk, you will need to build an -array of pointers to each row, as it will be needed for some -of the functions below. - -Remember: Before you call png_read_update_info(), the png_get_*() -functions return the values corresponding to the original PNG image. -After you call png_read_update_info the values refer to the image -that libpng will output. Consequently you must call all the png_set_ -functions before you call png_read_update_info(). This is particularly -important for png_set_interlace_handling() - if you are going to call -png_read_update_info() you must call png_set_interlace_handling() before -it unless you want to receive interlaced output. - -Reading image data - -After you've allocated memory, you can read the image data. -The simplest way to do this is in one function call. If you are -allocating enough memory to hold the whole image, you can just -call png_read_image() and libpng will read in all the image data -and put it in the memory area supplied. You will need to pass in -an array of pointers to each row. - -This function automatically handles interlacing, so you don't -need to call png_set_interlace_handling() (unless you call -png_read_update_info()) or call this function multiple times, or any -of that other stuff necessary with png_read_rows(). - - png_read_image(png_ptr, row_pointers); - -where row_pointers is: - - png_bytep row_pointers[height]; - -You can point to void or char or whatever you use for pixels. - -If you don't want to read in the whole image at once, you can -use png_read_rows() instead. If there is no interlacing (check -interlace_type == PNG_INTERLACE_NONE), this is simple: - - png_read_rows(png_ptr, row_pointers, NULL, - number_of_rows); - -where row_pointers is the same as in the png_read_image() call. - -If you are doing this just one row at a time, you can do this with -a single row_pointer instead of an array of row_pointers: - - png_bytep row_pointer = row; - png_read_row(png_ptr, row_pointer, NULL); - -If the file is interlaced (interlace_type != 0 in the IHDR chunk), things -get somewhat harder. The only current (PNG Specification version 1.2) -interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7); -a somewhat complicated 2D interlace scheme, known as Adam7, that -breaks down an image into seven smaller images of varying size, based -on an 8x8 grid. This number is defined (from libpng 1.5) as -PNG_INTERLACE_ADAM7_PASSES in png.h - -libpng can fill out those images or it can give them to you "as is". -It is almost always better to have libpng handle the interlacing for you. -If you want the images filled out, there are two ways to do that. The one -mentioned in the PNG specification is to expand each pixel to cover -those pixels that have not been read yet (the "rectangle" method). -This results in a blocky image for the first pass, which gradually -smooths out as more pixels are read. The other method is the "sparkle" -method, where pixels are drawn only in their final locations, with the -rest of the image remaining whatever colors they were initialized to -before the start of the read. The first method usually looks better, -but tends to be slower, as there are more pixels to put in the rows. - -If, as is likely, you want libpng to expand the images, call this before -calling png_start_read_image() or png_read_update_info(): - - if (interlace_type == PNG_INTERLACE_ADAM7) - number_of_passes - = png_set_interlace_handling(png_ptr); - -This will return the number of passes needed. Currently, this is seven, -but may change if another interlace type is added. This function can be -called even if the file is not interlaced, where it will return one pass. -You then need to read the whole image 'number_of_passes' times. Each time -will distribute the pixels from the current pass to the correct place in -the output image, so you need to supply the same rows to png_read_rows in -each pass. - -If you are not going to display the image after each pass, but are -going to wait until the entire image is read in, use the sparkle -effect. This effect is faster and the end result of either method -is exactly the same. If you are planning on displaying the image -after each pass, the "rectangle" effect is generally considered the -better looking one. - -If you only want the "sparkle" effect, just call png_read_rows() as -normal, with the third parameter NULL. Make sure you make pass over -the image number_of_passes times, and you don't change the data in the -rows between calls. You can change the locations of the data, just -not the data. Each pass only writes the pixels appropriate for that -pass, and assumes the data from previous passes is still valid. - - png_read_rows(png_ptr, row_pointers, NULL, - number_of_rows); - -If you only want the first effect (the rectangles), do the same as -before except pass the row buffer in the third parameter, and leave -the second parameter NULL. - - png_read_rows(png_ptr, NULL, row_pointers, - number_of_rows); - -If you don't want libpng to handle the interlacing details, just call -png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images. -Each of the images is a valid image by itself; however, you will almost -certainly need to distribute the pixels from each sub-image to the -correct place. This is where everything gets very tricky. - -If you want to retrieve the separate images you must pass the correct -number of rows to each successive call of png_read_rows(). The calculation -gets pretty complicated for small images, where some sub-images may -not even exist because either their width or height ends up zero. -libpng provides two macros to help you in 1.5 and later versions: - - png_uint_32 width = PNG_PASS_COLS(image_width, pass_number); - png_uint_32 height = PNG_PASS_ROWS(image_height, pass_number); - -Respectively these tell you the width and height of the sub-image -corresponding to the numbered pass. 'pass' is in in the range 0 to 6 - -this can be confusing because the specification refers to the same passes -as 1 to 7! Be careful, you must check both the width and height before -calling png_read_rows() and not call it for that pass if either is zero. - -You can, of course, read each sub-image row by row. If you want to -produce optimal code to make a pixel-by-pixel transformation of an -interlaced image this is the best approach; read each row of each pass, -transform it, and write it out to a new interlaced image. - -If you want to de-interlace the image yourself libpng provides further -macros to help that tell you where to place the pixels in the output image. -Because the interlacing scheme is rectangular - sub-image pixels are always -arranged on a rectangular grid - all you need to know for each pass is the -starting column and row in the output image of the first pixel plus the -spacing between each pixel. As of libpng 1.5 there are four macros to -retrieve this information: - - png_uint_32 x = PNG_PASS_START_COL(pass); - png_uint_32 y = PNG_PASS_START_ROW(pass); - png_uint_32 xStep = 1U << PNG_PASS_COL_SHIFT(pass); - png_uint_32 yStep = 1U << PNG_PASS_ROW_SHIFT(pass); - -These allow you to write the obvious loop: - - png_uint_32 input_y = 0; - png_uint_32 output_y = PNG_PASS_START_ROW(pass); - - while (output_y < output_image_height) - { - png_uint_32 input_x = 0; - png_uint_32 output_x = PNG_PASS_START_COL(pass); - - while (output_x < output_image_width) - { - image[output_y][output_x] = - subimage[pass][input_y][input_x++]; - - output_x += xStep; - } - - ++input_y; - output_y += yStep; - } - -Notice that the steps between successive output rows and columns are -returned as shifts. This is possible because the pixels in the subimages -are always a power of 2 apart - 1, 2, 4 or 8 pixels - in the original -image. In practice you may need to directly calculate the output coordinate -given an input coordinate. libpng provides two further macros for this -purpose: - - png_uint_32 output_x = PNG_COL_FROM_PASS_COL(input_x, pass); - png_uint_32 output_y = PNG_ROW_FROM_PASS_ROW(input_y, pass); - -Finally a pair of macros are provided to tell you if a particular image -row or column appears in a given pass: - - int col_in_pass = PNG_COL_IN_INTERLACE_PASS(output_x, pass); - int row_in_pass = PNG_ROW_IN_INTERLACE_PASS(output_y, pass); - -Bear in mind that you will probably also need to check the width and height -of the pass in addition to the above to be sure the pass even exists! - -With any luck you are convinced by now that you don't want to do your own -interlace handling. In reality normally the only good reason for doing this -is if you are processing PNG files on a pixel-by-pixel basis and don't want -to load the whole file into memory when it is interlaced. - -libpng includes a test program, pngvalid, that illustrates reading and -writing of interlaced images. If you can't get interlacing to work in your -code and don't want to leave it to libpng (the recommended approach), see -how pngvalid.c does it. - -Finishing a sequential read - -After you are finished reading the image through the -low-level interface, you can finish reading the file. - -If you want to use a different crc action for handling CRC errors in -chunks after the image data, you can call png_set_crc_action() -again at this point. - -If you are interested in comments or time, which may be stored either -before or after the image data, you should pass the separate png_info -struct if you want to keep the comments from before and after the image -separate. - - png_infop end_info = png_create_info_struct(png_ptr); - - if (!end_info) - { - png_destroy_read_struct(&png_ptr, &info_ptr, - (png_infopp)NULL); - return (ERROR); - } - - png_read_end(png_ptr, end_info); - -If you are not interested, you should still call png_read_end() -but you can pass NULL, avoiding the need to create an end_info structure. -If you do this, libpng will not process any chunks after IDAT other than -skipping over them and perhaps (depending on whether you have called -png_set_crc_action) checking their CRCs while looking for the IEND chunk. - - png_read_end(png_ptr, (png_infop)NULL); - -If you don't call png_read_end(), then your file pointer will be -left pointing to the first chunk after the last IDAT, which is probably -not what you want if you expect to read something beyond the end of -the PNG datastream. - -When you are done, you can free all memory allocated by libpng like this: - - png_destroy_read_struct(&png_ptr, &info_ptr, - &end_info); - -or, if you didn't create an end_info structure, - - png_destroy_read_struct(&png_ptr, &info_ptr, - (png_infopp)NULL); - -It is also possible to individually free the info_ptr members that -point to libpng-allocated storage with the following function: - - png_free_data(png_ptr, info_ptr, mask, seq) - - mask - identifies data to be freed, a mask - containing the bitwise OR of one or - more of - PNG_FREE_PLTE, PNG_FREE_TRNS, - PNG_FREE_HIST, PNG_FREE_ICCP, - PNG_FREE_PCAL, PNG_FREE_ROWS, - PNG_FREE_SCAL, PNG_FREE_SPLT, - PNG_FREE_TEXT, PNG_FREE_UNKN, - or simply PNG_FREE_ALL - - seq - sequence number of item to be freed - (-1 for all items) - -This function may be safely called when the relevant storage has -already been freed, or has not yet been allocated, or was allocated -by the user and not by libpng, and will in those cases do nothing. -The "seq" parameter is ignored if only one item of the selected data -type, such as PLTE, is allowed. If "seq" is not -1, and multiple items -are allowed for the data type identified in the mask, such as text or -sPLT, only the n'th item in the structure is freed, where n is "seq". - -The default behavior is only to free data that was allocated internally -by libpng. This can be changed, so that libpng will not free the data, -or so that it will free data that was allocated by the user with png_malloc() -or png_calloc() and passed in via a png_set_*() function, with - - png_data_freer(png_ptr, info_ptr, freer, mask) - - freer - one of - PNG_DESTROY_WILL_FREE_DATA - PNG_SET_WILL_FREE_DATA - PNG_USER_WILL_FREE_DATA - - mask - which data elements are affected - same choices as in png_free_data() - -This function only affects data that has already been allocated. -You can call this function after reading the PNG data but before calling -any png_set_*() functions, to control whether the user or the png_set_*() -function is responsible for freeing any existing data that might be present, -and again after the png_set_*() functions to control whether the user -or png_destroy_*() is supposed to free the data. When the user assumes -responsibility for libpng-allocated data, the application must use -png_free() to free it, and when the user transfers responsibility to libpng -for data that the user has allocated, the user must have used png_malloc() -or png_calloc() to allocate it. - -If you allocated your row_pointers in a single block, as suggested above in -the description of the high level read interface, you must not transfer -responsibility for freeing it to the png_set_rows or png_read_destroy function, -because they would also try to free the individual row_pointers[i]. - -If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword -separately, do not transfer responsibility for freeing text_ptr to libpng, -because when libpng fills a png_text structure it combines these members with -the key member, and png_free_data() will free only text_ptr.key. Similarly, -if you transfer responsibility for free'ing text_ptr from libpng to your -application, your application must not separately free those members. - -The png_free_data() function will turn off the "valid" flag for anything -it frees. If you need to turn the flag off for a chunk that was freed by -your application instead of by libpng, you can use - - png_set_invalid(png_ptr, info_ptr, mask); - - mask - identifies the chunks to be made invalid, - containing the bitwise OR of one or - more of - PNG_INFO_gAMA, PNG_INFO_sBIT, - PNG_INFO_cHRM, PNG_INFO_PLTE, - PNG_INFO_tRNS, PNG_INFO_bKGD, - PNG_INFO_hIST, PNG_INFO_pHYs, - PNG_INFO_oFFs, PNG_INFO_tIME, - PNG_INFO_pCAL, PNG_INFO_sRGB, - PNG_INFO_iCCP, PNG_INFO_sPLT, - PNG_INFO_sCAL, PNG_INFO_IDAT - -For a more compact example of reading a PNG image, see the file example.c. - -Reading PNG files progressively - -The progressive reader is slightly different from the non-progressive -reader. Instead of calling png_read_info(), png_read_rows(), and -png_read_end(), you make one call to png_process_data(), which calls -callbacks when it has the info, a row, or the end of the image. You -set up these callbacks with png_set_progressive_read_fn(). You don't -have to worry about the input/output functions of libpng, as you are -giving the library the data directly in png_process_data(). I will -assume that you have read the section on reading PNG files above, -so I will only highlight the differences (although I will show -all of the code). - -png_structp png_ptr; -png_infop info_ptr; - - /* An example code fragment of how you would - initialize the progressive reader in your - application. */ - int - initialize_png_reader() - { - png_ptr = png_create_read_struct - (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, - user_error_fn, user_warning_fn); - - if (!png_ptr) - return (ERROR); - - info_ptr = png_create_info_struct(png_ptr); - - if (!info_ptr) - { - png_destroy_read_struct(&png_ptr, - (png_infopp)NULL, (png_infopp)NULL); - return (ERROR); - } - - if (setjmp(png_jmpbuf(png_ptr))) - { - png_destroy_read_struct(&png_ptr, &info_ptr, - (png_infopp)NULL); - return (ERROR); - } - - /* This one's new. You can provide functions - to be called when the header info is valid, - when each row is completed, and when the image - is finished. If you aren't using all functions, - you can specify NULL parameters. Even when all - three functions are NULL, you need to call - png_set_progressive_read_fn(). You can use - any struct as the user_ptr (cast to a void pointer - for the function call), and retrieve the pointer - from inside the callbacks using the function - - png_get_progressive_ptr(png_ptr); - - which will return a void pointer, which you have - to cast appropriately. - */ - png_set_progressive_read_fn(png_ptr, (void *)user_ptr, - info_callback, row_callback, end_callback); - - return 0; - } - - /* A code fragment that you call as you receive blocks - of data */ - int - process_data(png_bytep buffer, png_uint_32 length) - { - if (setjmp(png_jmpbuf(png_ptr))) - { - png_destroy_read_struct(&png_ptr, &info_ptr, - (png_infopp)NULL); - return (ERROR); - } - - /* This one's new also. Simply give it a chunk - of data from the file stream (in order, of - course). On machines with segmented memory - models machines, don't give it any more than - 64K. The library seems to run fine with sizes - of 4K. Although you can give it much less if - necessary (I assume you can give it chunks of - 1 byte, I haven't tried less than 256 bytes - yet). When this function returns, you may - want to display any rows that were generated - in the row callback if you don't already do - so there. - */ - png_process_data(png_ptr, info_ptr, buffer, length); - - /* At this point you can call png_process_data_skip if - you want to handle data the library will skip yourself; - it simply returns the number of bytes to skip (and stops - libpng skipping that number of bytes on the next - png_process_data call). - return 0; - } - - /* This function is called (as set by - png_set_progressive_read_fn() above) when enough data - has been supplied so all of the header has been - read. - */ - void - info_callback(png_structp png_ptr, png_infop info) - { - /* Do any setup here, including setting any of - the transformations mentioned in the Reading - PNG files section. For now, you _must_ call - either png_start_read_image() or - png_read_update_info() after all the - transformations are set (even if you don't set - any). You may start getting rows before - png_process_data() returns, so this is your - last chance to prepare for that. - - This is where you turn on interlace handling, - assuming you don't want to do it yourself. - - If you need to you can stop the processing of - your original input data at this point by calling - png_process_data_pause. This returns the number - of unprocessed bytes from the last png_process_data - call - it is up to you to ensure that the next call - sees these bytes again. If you don't want to bother - with this you can get libpng to cache the unread - bytes by setting the 'save' parameter (see png.h) but - then libpng will have to copy the data internally. - */ - } - - /* This function is called when each row of image - data is complete */ - void - row_callback(png_structp png_ptr, png_bytep new_row, - png_uint_32 row_num, int pass) - { - /* If the image is interlaced, and you turned - on the interlace handler, this function will - be called for every row in every pass. Some - of these rows will not be changed from the - previous pass. When the row is not changed, - the new_row variable will be NULL. The rows - and passes are called in order, so you don't - really need the row_num and pass, but I'm - supplying them because it may make your life - easier. - - If you did not turn on interlace handling then - the callback is called for each row of each - sub-image when the image is interlaced. In this - case 'row_num' is the row in the sub-image, not - the row in the output image as it is in all other - cases. - - For the non-NULL rows of interlaced images when - you have switched on libpng interlace handling, - you must call png_progressive_combine_row() - passing in the row and the old row. You can - call this function for NULL rows (it will just - return) and for non-interlaced images (it just - does the memcpy for you) if it will make the - code easier. Thus, you can just do this for - all cases if you switch on interlace handling; - */ - - png_progressive_combine_row(png_ptr, old_row, - new_row); - - /* where old_row is what was displayed - previously for the row. Note that the first - pass (pass == 0, really) will completely cover - the old row, so the rows do not have to be - initialized. After the first pass (and only - for interlaced images), you will have to pass - the current row, and the function will combine - the old row and the new row. - - You can also call png_process_data_pause in this - callback - see above. - */ - } - - void - end_callback(png_structp png_ptr, png_infop info) - { - /* This function is called after the whole image - has been read, including any chunks after the - image (up to and including the IEND). You - will usually have the same info chunk as you - had in the header, although some data may have - been added to the comments and time fields. - - Most people won't do much here, perhaps setting - a flag that marks the image as finished. - */ - } - - - -IV. Writing - -Much of this is very similar to reading. However, everything of -importance is repeated here, so you won't have to constantly look -back up in the reading section to understand writing. - -Setup - -You will want to do the I/O initialization before you get into libpng, -so if it doesn't work, you don't have anything to undo. If you are not -using the standard I/O functions, you will need to replace them with -custom writing functions. See the discussion under Customizing libpng. - - FILE *fp = fopen(file_name, "wb"); - - if (!fp) - return (ERROR); - -Next, png_struct and png_info need to be allocated and initialized. -As these can be both relatively large, you may not want to store these -on the stack, unless you have stack space to spare. Of course, you -will want to check if they return NULL. If you are also reading, -you won't want to name your read structure and your write structure -both "png_ptr"; you can call them anything you like, such as -"read_ptr" and "write_ptr". Look at pngtest.c, for example. - - png_structp png_ptr = png_create_write_struct - (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, - user_error_fn, user_warning_fn); - - if (!png_ptr) - return (ERROR); - - png_infop info_ptr = png_create_info_struct(png_ptr); - if (!info_ptr) - { - png_destroy_write_struct(&png_ptr, - (png_infopp)NULL); - return (ERROR); - } - -If you want to use your own memory allocation routines, -define PNG_USER_MEM_SUPPORTED and use -png_create_write_struct_2() instead of png_create_write_struct(): - - png_structp png_ptr = png_create_write_struct_2 - (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, - user_error_fn, user_warning_fn, (png_voidp) - user_mem_ptr, user_malloc_fn, user_free_fn); - -After you have these structures, you will need to set up the -error handling. When libpng encounters an error, it expects to -longjmp() back to your routine. Therefore, you will need to call -setjmp() and pass the png_jmpbuf(png_ptr). If you -write the file from different routines, you will need to update -the png_jmpbuf(png_ptr) every time you enter a new routine that will -call a png_*() function. See your documentation of setjmp/longjmp -for your compiler for more information on setjmp/longjmp. See -the discussion on libpng error handling in the Customizing Libpng -section below for more information on the libpng error handling. - - if (setjmp(png_jmpbuf(png_ptr))) - { - png_destroy_write_struct(&png_ptr, &info_ptr); - fclose(fp); - return (ERROR); - } - ... - return; - -If you would rather avoid the complexity of setjmp/longjmp issues, -you can compile libpng with PNG_NO_SETJMP, in which case -errors will result in a call to PNG_ABORT() which defaults to abort(). - -You can #define PNG_ABORT() to a function that does something -more useful than abort(), as long as your function does not -return. - -Checking for invalid palette index on write was added at libpng -1.5.10. If a pixel contains an invalid (out-of-range) index libpng issues -a benign error. This is enabled by default because this condition is an -error according to the PNG specification, Clause 11.3.2, but the error can -be ignored in each png_ptr with - - png_set_check_for_invalid_index(png_ptr, 0); - -If the error is ignored, or if png_benign_error() treats it as a warning, -any invalid pixels are written as-is by the encoder, resulting in an -invalid PNG datastream as output. In this case the application is -responsible for ensuring that the pixel indexes are in range when it writes -a PLTE chunk with fewer entries than the bit depth would allow. - -Now you need to set up the output code. The default for libpng is to -use the C function fwrite(). If you use this, you will need to pass a -valid FILE * in the function png_init_io(). Be sure that the file is -opened in binary mode. Again, if you wish to handle writing data in -another way, see the discussion on libpng I/O handling in the Customizing -Libpng section below. - - png_init_io(png_ptr, fp); - -If you are embedding your PNG into a datastream such as MNG, and don't -want libpng to write the 8-byte signature, or if you have already -written the signature in your application, use - - png_set_sig_bytes(png_ptr, 8); - -to inform libpng that it should not write a signature. - -Write callbacks - -At this point, you can set up a callback function that will be -called after each row has been written, which you can use to control -a progress meter or the like. It's demonstrated in pngtest.c. -You must supply a function - - void write_row_callback(png_structp png_ptr, png_uint_32 row, - int pass); - { - /* put your code here */ - } - -(You can give it another name that you like instead of "write_row_callback") - -To inform libpng about your function, use - - png_set_write_status_fn(png_ptr, write_row_callback); - -When this function is called the row has already been completely processed and -it has also been written out. The 'row' and 'pass' refer to the next row to be -handled. For the -non-interlaced case the row that was just handled is simply one less than the -passed in row number, and pass will always be 0. For the interlaced case the -same applies unless the row value is 0, in which case the row just handled was -the last one from one of the preceding passes. Because interlacing may skip a -pass you cannot be sure that the preceding pass is just 'pass-1', if you really -need to know what the last pass is record (row,pass) from the callback and use -the last recorded value each time. - -As with the user transform you can find the output row using the -PNG_ROW_FROM_PASS_ROW macro. - -You now have the option of modifying how the compression library will -run. The following functions are mainly for testing, but may be useful -in some cases, like if you need to write PNG files extremely fast and -are willing to give up some compression, or if you want to get the -maximum possible compression at the expense of slower writing. If you -have no special needs in this area, let the library do what it wants by -not calling this function at all, as it has been tuned to deliver a good -speed/compression ratio. The second parameter to png_set_filter() is -the filter method, for which the only valid values are 0 (as of the -July 1999 PNG specification, version 1.2) or 64 (if you are writing -a PNG datastream that is to be embedded in a MNG datastream). The third -parameter is a flag that indicates which filter type(s) are to be tested -for each scanline. See the PNG specification for details on the specific -filter types. - - - /* turn on or off filtering, and/or choose - specific filters. You can use either a single - PNG_FILTER_VALUE_NAME or the bitwise OR of one - or more PNG_FILTER_NAME masks. - */ - png_set_filter(png_ptr, 0, - PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE | - PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB | - PNG_FILTER_UP | PNG_FILTER_VALUE_UP | - PNG_FILTER_AVG | PNG_FILTER_VALUE_AVG | - PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH| - PNG_ALL_FILTERS | PNG_FAST_FILTERS); - -If an application wants to start and stop using particular filters during -compression, it should start out with all of the filters (to ensure that -the previous row of pixels will be stored in case it's needed later), -and then add and remove them after the start of compression. - -If you are writing a PNG datastream that is to be embedded in a MNG -datastream, the second parameter can be either 0 or 64. - -The png_set_compression_*() functions interface to the zlib compression -library, and should mostly be ignored unless you really know what you are -doing. The only generally useful call is png_set_compression_level() -which changes how much time zlib spends on trying to compress the image -data. See the Compression Library (zlib.h and algorithm.txt, distributed -with zlib) for details on the compression levels. - - #include zlib.h - - /* Set the zlib compression level */ - png_set_compression_level(png_ptr, - Z_BEST_COMPRESSION); - - /* Set other zlib parameters for compressing IDAT */ - png_set_compression_mem_level(png_ptr, 8); - png_set_compression_strategy(png_ptr, - Z_DEFAULT_STRATEGY); - png_set_compression_window_bits(png_ptr, 15); - png_set_compression_method(png_ptr, 8); - png_set_compression_buffer_size(png_ptr, 8192) - - /* Set zlib parameters for text compression - * If you don't call these, the parameters - * fall back on those defined for IDAT chunks - */ - png_set_text_compression_mem_level(png_ptr, 8); - png_set_text_compression_strategy(png_ptr, - Z_DEFAULT_STRATEGY); - png_set_text_compression_window_bits(png_ptr, 15); - png_set_text_compression_method(png_ptr, 8); - -Setting the contents of info for output - -You now need to fill in the png_info structure with all the data you -wish to write before the actual image. Note that the only thing you -are allowed to write after the image is the text chunks and the time -chunk (as of PNG Specification 1.2, anyway). See png_write_end() and -the latest PNG specification for more information on that. If you -wish to write them before the image, fill them in now, and flag that -data as being valid. If you want to wait until after the data, don't -fill them until png_write_end(). For all the fields in png_info and -their data types, see png.h. For explanations of what the fields -contain, see the PNG specification. - -Some of the more important parts of the png_info are: - - png_set_IHDR(png_ptr, info_ptr, width, height, - bit_depth, color_type, interlace_type, - compression_type, filter_method) - - width - holds the width of the image - in pixels (up to 2^31). - - height - holds the height of the image - in pixels (up to 2^31). - - bit_depth - holds the bit depth of one of the - image channels. - (valid values are 1, 2, 4, 8, 16 - and depend also on the - color_type. See also significant - bits (sBIT) below). - - color_type - describes which color/alpha - channels are present. - PNG_COLOR_TYPE_GRAY - (bit depths 1, 2, 4, 8, 16) - PNG_COLOR_TYPE_GRAY_ALPHA - (bit depths 8, 16) - PNG_COLOR_TYPE_PALETTE - (bit depths 1, 2, 4, 8) - PNG_COLOR_TYPE_RGB - (bit_depths 8, 16) - PNG_COLOR_TYPE_RGB_ALPHA - (bit_depths 8, 16) - - PNG_COLOR_MASK_PALETTE - PNG_COLOR_MASK_COLOR - PNG_COLOR_MASK_ALPHA - - interlace_type - PNG_INTERLACE_NONE or - PNG_INTERLACE_ADAM7 - - compression_type - (must be - PNG_COMPRESSION_TYPE_DEFAULT) - - filter_method - (must be PNG_FILTER_TYPE_DEFAULT - or, if you are writing a PNG to - be embedded in a MNG datastream, - can also be - PNG_INTRAPIXEL_DIFFERENCING) - -If you call png_set_IHDR(), the call must appear before any of the -other png_set_*() functions, because they might require access to some of -the IHDR settings. The remaining png_set_*() functions can be called -in any order. - -If you wish, you can reset the compression_type, interlace_type, or -filter_method later by calling png_set_IHDR() again; if you do this, the -width, height, bit_depth, and color_type must be the same in each call. - - png_set_PLTE(png_ptr, info_ptr, palette, - num_palette); - - palette - the palette for the file - (array of png_color) - num_palette - number of entries in the palette - - - png_set_gAMA(png_ptr, info_ptr, file_gamma); - png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma); - - file_gamma - the gamma at which the image was - created (PNG_INFO_gAMA) - - int_file_gamma - 100,000 times the gamma at which - the image was created - - png_set_cHRM(png_ptr, info_ptr, white_x, white_y, red_x, red_y, - green_x, green_y, blue_x, blue_y) - png_set_cHRM_XYZ(png_ptr, info_ptr, red_X, red_Y, red_Z, green_X, - green_Y, green_Z, blue_X, blue_Y, blue_Z) - png_set_cHRM_fixed(png_ptr, info_ptr, int_white_x, int_white_y, - int_red_x, int_red_y, int_green_x, int_green_y, - int_blue_x, int_blue_y) - png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, int_red_X, int_red_Y, - int_red_Z, int_green_X, int_green_Y, int_green_Z, - int_blue_X, int_blue_Y, int_blue_Z) - - {white,red,green,blue}_{x,y} - A color space encoding specified using the chromaticities - of the end points and the white point. - - {red,green,blue}_{X,Y,Z} - A color space encoding specified using the encoding end - points - the CIE tristimulus specification of the intended - color of the red, green and blue channels in the PNG RGB - data. The white point is simply the sum of the three end - points. - - png_set_sRGB(png_ptr, info_ptr, srgb_intent); - - srgb_intent - the rendering intent - (PNG_INFO_sRGB) The presence of - the sRGB chunk means that the pixel - data is in the sRGB color space. - This chunk also implies specific - values of gAMA and cHRM. Rendering - intent is the CSS-1 property that - has been defined by the International - Color Consortium - (http://www.color.org). - It can be one of - PNG_sRGB_INTENT_SATURATION, - PNG_sRGB_INTENT_PERCEPTUAL, - PNG_sRGB_INTENT_ABSOLUTE, or - PNG_sRGB_INTENT_RELATIVE. - - - png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, - srgb_intent); - - srgb_intent - the rendering intent - (PNG_INFO_sRGB) The presence of the - sRGB chunk means that the pixel - data is in the sRGB color space. - This function also causes gAMA and - cHRM chunks with the specific values - that are consistent with sRGB to be - written. - - png_set_iCCP(png_ptr, info_ptr, name, compression_type, - profile, proflen); - - name - The profile name. - - compression_type - The compression type; always - PNG_COMPRESSION_TYPE_BASE for PNG 1.0. - You may give NULL to this argument to - ignore it. - - profile - International Color Consortium color - profile data. May contain NULs. - - proflen - length of profile data in bytes. - - png_set_sBIT(png_ptr, info_ptr, sig_bit); - - sig_bit - the number of significant bits for - (PNG_INFO_sBIT) each of the gray, red, - green, and blue channels, whichever are - appropriate for the given color type - (png_color_16) - - png_set_tRNS(png_ptr, info_ptr, trans_alpha, - num_trans, trans_color); - - trans_alpha - array of alpha (transparency) - entries for palette (PNG_INFO_tRNS) - - num_trans - number of transparent entries - (PNG_INFO_tRNS) - - trans_color - graylevel or color sample values - (in order red, green, blue) of the - single transparent color for - non-paletted images (PNG_INFO_tRNS) - - png_set_hIST(png_ptr, info_ptr, hist); - - hist - histogram of palette (array of - png_uint_16) (PNG_INFO_hIST) - - png_set_tIME(png_ptr, info_ptr, mod_time); - - mod_time - time image was last modified - (PNG_VALID_tIME) - - png_set_bKGD(png_ptr, info_ptr, background); - - background - background color (of type - png_color_16p) (PNG_VALID_bKGD) - - png_set_text(png_ptr, info_ptr, text_ptr, num_text); - - text_ptr - array of png_text holding image - comments - - text_ptr[i].compression - type of compression used - on "text" PNG_TEXT_COMPRESSION_NONE - PNG_TEXT_COMPRESSION_zTXt - PNG_ITXT_COMPRESSION_NONE - PNG_ITXT_COMPRESSION_zTXt - text_ptr[i].key - keyword for comment. Must contain - 1-79 characters. - text_ptr[i].text - text comments for current - keyword. Can be NULL or empty. - text_ptr[i].text_length - length of text string, - after decompression, 0 for iTXt - text_ptr[i].itxt_length - length of itxt string, - after decompression, 0 for tEXt/zTXt - text_ptr[i].lang - language of comment (NULL or - empty for unknown). - text_ptr[i].translated_keyword - keyword in UTF-8 (NULL - or empty for unknown). - - Note that the itxt_length, lang, and lang_key - members of the text_ptr structure only exist when the - library is built with iTXt chunk support. Prior to - libpng-1.4.0 the library was built by default without - iTXt support. Also note that when iTXt is supported, - they contain NULL pointers when the "compression" - field contains PNG_TEXT_COMPRESSION_NONE or - PNG_TEXT_COMPRESSION_zTXt. - - num_text - number of comments - - png_set_sPLT(png_ptr, info_ptr, &palette_ptr, - num_spalettes); - - palette_ptr - array of png_sPLT_struct structures - to be added to the list of palettes - in the info structure. - num_spalettes - number of palette structures to be - added. - - png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, - unit_type); - - offset_x - positive offset from the left - edge of the screen - - offset_y - positive offset from the top - edge of the screen - - unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER - - png_set_pHYs(png_ptr, info_ptr, res_x, res_y, - unit_type); - - res_x - pixels/unit physical resolution - in x direction - - res_y - pixels/unit physical resolution - in y direction - - unit_type - PNG_RESOLUTION_UNKNOWN, - PNG_RESOLUTION_METER - - png_set_sCAL(png_ptr, info_ptr, unit, width, height) - - unit - physical scale units (an integer) - - width - width of a pixel in physical scale units - - height - height of a pixel in physical scale units - (width and height are doubles) - - png_set_sCAL_s(png_ptr, info_ptr, unit, width, height) - - unit - physical scale units (an integer) - - width - width of a pixel in physical scale units - expressed as a string - - height - height of a pixel in physical scale units - (width and height are strings like "2.54") - - png_set_unknown_chunks(png_ptr, info_ptr, &unknowns, - num_unknowns) - - unknowns - array of png_unknown_chunk - structures holding unknown chunks - unknowns[i].name - name of unknown chunk - unknowns[i].data - data of unknown chunk - unknowns[i].size - size of unknown chunk's data - unknowns[i].location - position to write chunk in file - 0: do not write chunk - PNG_HAVE_IHDR: before PLTE - PNG_HAVE_PLTE: before IDAT - PNG_AFTER_IDAT: after IDAT - -The "location" member is set automatically according to -what part of the output file has already been written. -You can change its value after calling png_set_unknown_chunks() -as demonstrated in pngtest.c. Within each of the "locations", -the chunks are sequenced according to their position in the -structure (that is, the value of "i", which is the order in which -the chunk was either read from the input file or defined with -png_set_unknown_chunks). - -A quick word about text and num_text. text is an array of png_text -structures. num_text is the number of valid structures in the array. -Each png_text structure holds a language code, a keyword, a text value, -and a compression type. - -The compression types have the same valid numbers as the compression -types of the image data. Currently, the only valid number is zero. -However, you can store text either compressed or uncompressed, unlike -images, which always have to be compressed. So if you don't want the -text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE. -Because tEXt and zTXt chunks don't have a language field, if you -specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt -any language code or translated keyword will not be written out. - -Until text gets around a few hundred bytes, it is not worth compressing it. -After the text has been written out to the file, the compression type -is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR, -so that it isn't written out again at the end (in case you are calling -png_write_end() with the same struct). - -The keywords that are given in the PNG Specification are: - - Title Short (one line) title or - caption for image - - Author Name of image's creator - - Description Description of image (possibly long) - - Copyright Copyright notice - - Creation Time Time of original image creation - (usually RFC 1123 format, see below) - - Software Software used to create the image - - Disclaimer Legal disclaimer - - Warning Warning of nature of content - - Source Device used to create the image - - Comment Miscellaneous comment; conversion - from other image format - -The keyword-text pairs work like this. Keywords should be short -simple descriptions of what the comment is about. Some typical -keywords are found in the PNG specification, as is some recommendations -on keywords. You can repeat keywords in a file. You can even write -some text before the image and some after. For example, you may want -to put a description of the image before the image, but leave the -disclaimer until after, so viewers working over modem connections -don't have to wait for the disclaimer to go over the modem before -they start seeing the image. Finally, keywords should be full -words, not abbreviations. Keywords and text are in the ISO 8859-1 -(Latin-1) character set (a superset of regular ASCII) and can not -contain NUL characters, and should not contain control or other -unprintable characters. To make the comments widely readable, stick -with basic ASCII, and avoid machine specific character set extensions -like the IBM-PC character set. The keyword must be present, but -you can leave off the text string on non-compressed pairs. -Compressed pairs must have a text string, as only the text string -is compressed anyway, so the compression would be meaningless. - -PNG supports modification time via the png_time structure. Two -conversion routines are provided, png_convert_from_time_t() for -time_t and png_convert_from_struct_tm() for struct tm. The -time_t routine uses gmtime(). You don't have to use either of -these, but if you wish to fill in the png_time structure directly, -you should provide the time in universal time (GMT) if possible -instead of your local time. Note that the year number is the full -year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and -that months start with 1. - -If you want to store the time of the original image creation, you should -use a plain tEXt chunk with the "Creation Time" keyword. This is -necessary because the "creation time" of a PNG image is somewhat vague, -depending on whether you mean the PNG file, the time the image was -created in a non-PNG format, a still photo from which the image was -scanned, or possibly the subject matter itself. In order to facilitate -machine-readable dates, it is recommended that the "Creation Time" -tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"), -although this isn't a requirement. Unlike the tIME chunk, the -"Creation Time" tEXt chunk is not expected to be automatically changed -by the software. To facilitate the use of RFC 1123 dates, a function -png_convert_to_rfc1123_buffer(buffer, png_timep) is provided to -convert from PNG time to an RFC 1123 format string. The caller must provide -a writeable buffer of at least 29 bytes. - -Writing unknown chunks - -You can use the png_set_unknown_chunks function to queue up private chunks -for writing. You give it a chunk name, location, raw data, and a size. You -also must use png_set_keep_unknown_chunks() to ensure that libpng will -handle them. That's all there is to it. The chunks will be written by the -next following png_write_info_before_PLTE, png_write_info, or png_write_end -function, depending upon the specified location. Any chunks previously -read into the info structure's unknown-chunk list will also be written out -in a sequence that satisfies the PNG specification's ordering rules. - -Here is an example of writing two private chunks, prVt and miNE: - - #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - /* Set unknown chunk data */ - png_unknown_chunk unk_chunk[2]; - strcpy((char *) unk_chunk[0].name, "prVt"; - unk_chunk[0].data = (unsigned char *) "PRIVATE DATA"; - unk_chunk[0].size = strlen(unk_chunk[0].data)+1; - unk_chunk[0].location = PNG_HAVE_IHDR; - strcpy((char *) unk_chunk[1].name, "miNE"; - unk_chunk[1].data = (unsigned char *) "MY CHUNK DATA"; - unk_chunk[1].size = strlen(unk_chunk[0].data)+1; - unk_chunk[1].location = PNG_AFTER_IDAT; - png_set_unknown_chunks(write_ptr, write_info_ptr, - unk_chunk, 2); - /* Needed because miNE is not safe-to-copy */ - png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS, - (png_bytep) "miNE", 1); - # if PNG_LIBPNG_VER < 10600 - /* Deal with unknown chunk location bug in 1.5.x and earlier */ - png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR); - png_set_unknown_chunk_location(png, info, 1, PNG_AFTER_IDAT); - # endif - # if PNG_LIBPNG_VER < 10500 - /* PNG_AFTER_IDAT writes two copies of the chunk prior to libpng-1.5.0, - * one before IDAT and another after IDAT, so don't use it; only use - * PNG_HAVE_IHDR location. This call resets the location previously - * set by assignment and png_set_unknown_chunk_location() for chunk 1. - */ - png_set_unknown_chunk_location(png, info, 1, PNG_HAVE_IHDR); - # endif - #endif - -The high-level write interface - -At this point there are two ways to proceed; through the high-level -write interface, or through a sequence of low-level write operations. -You can use the high-level interface if your image data is present -in the info structure. All defined output -transformations are permitted, enabled by the following masks. - - PNG_TRANSFORM_IDENTITY No transformation - PNG_TRANSFORM_PACKING Pack 1, 2 and 4-bit samples - PNG_TRANSFORM_PACKSWAP Change order of packed - pixels to LSB first - PNG_TRANSFORM_INVERT_MONO Invert monochrome images - PNG_TRANSFORM_SHIFT Normalize pixels to the - sBIT depth - PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA - to BGRA - PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA - to AG - PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity - to transparency - PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples - PNG_TRANSFORM_STRIP_FILLER Strip out filler - bytes (deprecated). - PNG_TRANSFORM_STRIP_FILLER_BEFORE Strip out leading - filler bytes - PNG_TRANSFORM_STRIP_FILLER_AFTER Strip out trailing - filler bytes - -If you have valid image data in the info structure (you can use -png_set_rows() to put image data in the info structure), simply do this: - - png_write_png(png_ptr, info_ptr, png_transforms, NULL) - -where png_transforms is an integer containing the bitwise OR of some set of -transformation flags. This call is equivalent to png_write_info(), -followed the set of transformations indicated by the transform mask, -then png_write_image(), and finally png_write_end(). - -(The final parameter of this call is not yet used. Someday it might point -to transformation parameters required by some future output transform.) - -You must use png_transforms and not call any png_set_transform() functions -when you use png_write_png(). - -The low-level write interface - -If you are going the low-level route instead, you are now ready to -write all the file information up to the actual image data. You do -this with a call to png_write_info(). - - png_write_info(png_ptr, info_ptr); - -Note that there is one transformation you may need to do before -png_write_info(). In PNG files, the alpha channel in an image is the -level of opacity. If your data is supplied as a level of transparency, -you can invert the alpha channel before you write it, so that 0 is -fully transparent and 255 (in 8-bit or paletted images) or 65535 -(in 16-bit images) is fully opaque, with - - png_set_invert_alpha(png_ptr); - -This must appear before png_write_info() instead of later with the -other transformations because in the case of paletted images the tRNS -chunk data has to be inverted before the tRNS chunk is written. If -your image is not a paletted image, the tRNS data (which in such cases -represents a single color to be rendered as transparent) won't need to -be changed, and you can safely do this transformation after your -png_write_info() call. - -If you need to write a private chunk that you want to appear before -the PLTE chunk when PLTE is present, you can write the PNG info in -two steps, and insert code to write your own chunk between them: - - png_write_info_before_PLTE(png_ptr, info_ptr); - png_set_unknown_chunks(png_ptr, info_ptr, ...); - png_write_info(png_ptr, info_ptr); - -After you've written the file information, you can set up the library -to handle any special transformations of the image data. The various -ways to transform the data will be described in the order that they -should occur. This is important, as some of these change the color -type and/or bit depth of the data, and some others only work on -certain color types and bit depths. Even though each transformation -checks to see if it has data that it can do something with, you should -make sure to only enable a transformation if it will be valid for the -data. For example, don't swap red and blue on grayscale data. - -PNG files store RGB pixels packed into 3 or 6 bytes. This code tells -the library to strip input data that has 4 or 8 bytes per pixel down -to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2 -bytes per pixel). - - png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); - -where the 0 is unused, and the location is either PNG_FILLER_BEFORE or -PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel -is stored XRGB or RGBX. - -PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as -they can, resulting in, for example, 8 pixels per byte for 1 bit files. -If the data is supplied at 1 pixel per byte, use this code, which will -correctly pack the pixels into a single byte: - - png_set_packing(png_ptr); - -PNG files reduce possible bit depths to 1, 2, 4, 8, and 16. If your -data is of another bit depth, you can write an sBIT chunk into the -file so that decoders can recover the original data if desired. - - /* Set the true bit depth of the image data */ - if (color_type & PNG_COLOR_MASK_COLOR) - { - sig_bit.red = true_bit_depth; - sig_bit.green = true_bit_depth; - sig_bit.blue = true_bit_depth; - } - - else - { - sig_bit.gray = true_bit_depth; - } - - if (color_type & PNG_COLOR_MASK_ALPHA) - { - sig_bit.alpha = true_bit_depth; - } - - png_set_sBIT(png_ptr, info_ptr, &sig_bit); - -If the data is stored in the row buffer in a bit depth other than -one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG), -this will scale the values to appear to be the correct bit depth as -is required by PNG. - - png_set_shift(png_ptr, &sig_bit); - -PNG files store 16-bit pixels in network byte order (big-endian, -ie. most significant bits first). This code would be used if they are -supplied the other way (little-endian, i.e. least significant bits -first, the way PCs store them): - - if (bit_depth > 8) - png_set_swap(png_ptr); - -If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you -need to change the order the pixels are packed into bytes, you can use: - - if (bit_depth < 8) - png_set_packswap(png_ptr); - -PNG files store 3 color pixels in red, green, blue order. This code -would be used if they are supplied as blue, green, red: - - png_set_bgr(png_ptr); - -PNG files describe monochrome as black being zero and white being -one. This code would be used if the pixels are supplied with this reversed -(black being one and white being zero): - - png_set_invert_mono(png_ptr); - -Finally, you can write your own transformation function if none of -the existing ones meets your needs. This is done by setting a callback -with - - png_set_write_user_transform_fn(png_ptr, - write_transform_fn); - -You must supply the function - - void write_transform_fn(png_structp png_ptr, png_row_infop - row_info, png_bytep data) - -See pngtest.c for a working example. Your function will be called -before any of the other transformations are processed. If supported -libpng also supplies an information routine that may be called from -your callback: - - png_get_current_row_number(png_ptr); - png_get_current_pass_number(png_ptr); - -This returns the current row passed to the transform. With interlaced -images the value returned is the row in the input sub-image image. Use -PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to -find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass). - -The discussion of interlace handling above contains more information on how to -use these values. - -You can also set up a pointer to a user structure for use by your -callback function. - - png_set_user_transform_info(png_ptr, user_ptr, 0, 0); - -The user_channels and user_depth parameters of this function are ignored -when writing; you can set them to zero as shown. - -You can retrieve the pointer via the function png_get_user_transform_ptr(). -For example: - - voidp write_user_transform_ptr = - png_get_user_transform_ptr(png_ptr); - -It is possible to have libpng flush any pending output, either manually, -or automatically after a certain number of lines have been written. To -flush the output stream a single time call: - - png_write_flush(png_ptr); - -and to have libpng flush the output stream periodically after a certain -number of scanlines have been written, call: - - png_set_flush(png_ptr, nrows); - -Note that the distance between rows is from the last time png_write_flush() -was called, or the first row of the image if it has never been called. -So if you write 50 lines, and then png_set_flush 25, it will flush the -output on the next scanline, and every 25 lines thereafter, unless -png_write_flush() is called before 25 more lines have been written. -If nrows is too small (less than about 10 lines for a 640 pixel wide -RGB image) the image compression may decrease noticeably (although this -may be acceptable for real-time applications). Infrequent flushing will -only degrade the compression performance by a few percent over images -that do not use flushing. - -Writing the image data - -That's it for the transformations. Now you can write the image data. -The simplest way to do this is in one function call. If you have the -whole image in memory, you can just call png_write_image() and libpng -will write the image. You will need to pass in an array of pointers to -each row. This function automatically handles interlacing, so you don't -need to call png_set_interlace_handling() or call this function multiple -times, or any of that other stuff necessary with png_write_rows(). - - png_write_image(png_ptr, row_pointers); - -where row_pointers is: - - png_byte *row_pointers[height]; - -You can point to void or char or whatever you use for pixels. - -If you don't want to write the whole image at once, you can -use png_write_rows() instead. If the file is not interlaced, -this is simple: - - png_write_rows(png_ptr, row_pointers, - number_of_rows); - -row_pointers is the same as in the png_write_image() call. - -If you are just writing one row at a time, you can do this with -a single row_pointer instead of an array of row_pointers: - - png_bytep row_pointer = row; - - png_write_row(png_ptr, row_pointer); - -When the file is interlaced, things can get a good deal more complicated. -The only currently (as of the PNG Specification version 1.2, dated July -1999) defined interlacing scheme for PNG files is the "Adam7" interlace -scheme, that breaks down an image into seven smaller images of varying -size. libpng will build these images for you, or you can do them -yourself. If you want to build them yourself, see the PNG specification -for details of which pixels to write when. - -If you don't want libpng to handle the interlacing details, just -use png_set_interlace_handling() and call png_write_rows() the -correct number of times to write all the sub-images -(png_set_interlace_handling() returns the number of sub-images.) - -If you want libpng to build the sub-images, call this before you start -writing any rows: - - number_of_passes = png_set_interlace_handling(png_ptr); - -This will return the number of passes needed. Currently, this is seven, -but may change if another interlace type is added. - -Then write the complete image number_of_passes times. - - png_write_rows(png_ptr, row_pointers, number_of_rows); - -Think carefully before you write an interlaced image. Typically code that -reads such images reads all the image data into memory, uncompressed, before -doing any processing. Only code that can display an image on the fly can -take advantage of the interlacing and even then the image has to be exactly -the correct size for the output device, because scaling an image requires -adjacent pixels and these are not available until all the passes have been -read. - -If you do write an interlaced image you will hardly ever need to handle -the interlacing yourself. Call png_set_interlace_handling() and use the -approach described above. - -The only time it is conceivable that you will really need to write an -interlaced image pass-by-pass is when you have read one pass by pass and -made some pixel-by-pixel transformation to it, as described in the read -code above. In this case use the PNG_PASS_ROWS and PNG_PASS_COLS macros -to determine the size of each sub-image in turn and simply write the rows -you obtained from the read code. - -Finishing a sequential write - -After you are finished writing the image, you should finish writing -the file. If you are interested in writing comments or time, you should -pass an appropriately filled png_info pointer. If you are not interested, -you can pass NULL. - - png_write_end(png_ptr, info_ptr); - -When you are done, you can free all memory used by libpng like this: - - png_destroy_write_struct(&png_ptr, &info_ptr); - -It is also possible to individually free the info_ptr members that -point to libpng-allocated storage with the following function: - - png_free_data(png_ptr, info_ptr, mask, seq) - - mask - identifies data to be freed, a mask - containing the bitwise OR of one or - more of - PNG_FREE_PLTE, PNG_FREE_TRNS, - PNG_FREE_HIST, PNG_FREE_ICCP, - PNG_FREE_PCAL, PNG_FREE_ROWS, - PNG_FREE_SCAL, PNG_FREE_SPLT, - PNG_FREE_TEXT, PNG_FREE_UNKN, - or simply PNG_FREE_ALL - - seq - sequence number of item to be freed - (-1 for all items) - -This function may be safely called when the relevant storage has -already been freed, or has not yet been allocated, or was allocated -by the user and not by libpng, and will in those cases do nothing. -The "seq" parameter is ignored if only one item of the selected data -type, such as PLTE, is allowed. If "seq" is not -1, and multiple items -are allowed for the data type identified in the mask, such as text or -sPLT, only the n'th item in the structure is freed, where n is "seq". - -If you allocated data such as a palette that you passed in to libpng -with png_set_*, you must not free it until just before the call to -png_destroy_write_struct(). - -The default behavior is only to free data that was allocated internally -by libpng. This can be changed, so that libpng will not free the data, -or so that it will free data that was allocated by the user with png_malloc() -or png_calloc() and passed in via a png_set_*() function, with - - png_data_freer(png_ptr, info_ptr, freer, mask) - - freer - one of - PNG_DESTROY_WILL_FREE_DATA - PNG_SET_WILL_FREE_DATA - PNG_USER_WILL_FREE_DATA - - mask - which data elements are affected - same choices as in png_free_data() - -For example, to transfer responsibility for some data from a read structure -to a write structure, you could use - - png_data_freer(read_ptr, read_info_ptr, - PNG_USER_WILL_FREE_DATA, - PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST) - - png_data_freer(write_ptr, write_info_ptr, - PNG_DESTROY_WILL_FREE_DATA, - PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST) - -thereby briefly reassigning responsibility for freeing to the user but -immediately afterwards reassigning it once more to the write_destroy -function. Having done this, it would then be safe to destroy the read -structure and continue to use the PLTE, tRNS, and hIST data in the write -structure. - -This function only affects data that has already been allocated. -You can call this function before calling after the png_set_*() functions -to control whether the user or png_destroy_*() is supposed to free the data. -When the user assumes responsibility for libpng-allocated data, the -application must use -png_free() to free it, and when the user transfers responsibility to libpng -for data that the user has allocated, the user must have used png_malloc() -or png_calloc() to allocate it. - -If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword -separately, do not transfer responsibility for freeing text_ptr to libpng, -because when libpng fills a png_text structure it combines these members with -the key member, and png_free_data() will free only text_ptr.key. Similarly, -if you transfer responsibility for free'ing text_ptr from libpng to your -application, your application must not separately free those members. -For a more compact example of writing a PNG image, see the file example.c. - -V. Simplified API - -The simplified API, which became available in libpng-1.6.0, hides the details -of both libpng and the PNG file format itself. -It allows PNG files to be read into a very limited number of -in-memory bitmap formats or to be written from the same formats. If these -formats do not accommodate your needs then you can, and should, use the more -sophisticated APIs above - these support a wide variety of in-memory formats -and a wide variety of sophisticated transformations to those formats as well -as a wide variety of APIs to manipulate ancilliary information. - -To read a PNG file using the simplified API: - - 1) Declare a 'png_image' structure (see below) on the stack, set the - version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL - (this is REQUIRED, your program may crash if you don't do it.) - - 2) Call the appropriate png_image_begin_read... function. - - 3) Set the png_image 'format' member to the required sample format. - - 4) Allocate a buffer for the image and, if required, the color-map. - - 5) Call png_image_finish_read to read the image and, if required, the - color-map into your buffers. - -There are no restrictions on the format of the PNG input itself; all valid -color types, bit depths, and interlace methods are acceptable, and the -input image is transformed as necessary to the requested in-memory format -during the png_image_finish_read() step. The only caveat is that if you -request a color-mapped image from a PNG that is full-color or makes -complex use of an alpha channel the transformation is extremely lossy and the -result may look terrible. - -To write a PNG file using the simplified API: - - 1) Declare a 'png_image' structure on the stack and memset() - it to all zero. - - 2) Initialize the members of the structure that describe the - image, setting the 'format' member to the format of the - image samples. - - 3) Call the appropriate png_image_write... function with a - pointer to the image and, if necessary, the color-map to write - the PNG data. - -png_image is a structure that describes the in-memory format of an image -when it is being read or defines the in-memory format of an image that you -need to write. The "png_image" structure contains the following members: - - png_controlp opaque Initialize to NULL, free with png_image_free - png_uint_32 version Set to PNG_IMAGE_VERSION - png_uint_32 width Image width in pixels (columns) - png_uint_32 height Image height in pixels (rows) - png_uint_32 format Image format as defined below - png_uint_32 flags A bit mask containing informational flags - png_uint_32 colormap_entries; Number of entries in the color-map - png_uint_32 warning_or_error; - char message[64]; - -In the event of an error or warning the "warning_or_error" -field will be set to a non-zero value and the 'message' field will contain -a '\0' terminated string with the libpng error or warning message. If both -warnings and an error were encountered, only the error is recorded. If there -are multiple warnings, only the first one is recorded. - -The upper 30 bits of the "warning_or_error" value are reserved; the low two -bits contain a two bit code such that a value more than 1 indicates a failure -in the API just called: - - 0 - no warning or error - 1 - warning - 2 - error - 3 - error preceded by warning - -The pixels (samples) of the image have one to four channels whose components -have original values in the range 0 to 1.0: - - 1: A single gray or luminance channel (G). - 2: A gray/luminance channel and an alpha channel (GA). - 3: Three red, green, blue color channels (RGB). - 4: Three color channels and an alpha channel (RGBA). - -The channels are encoded in one of two ways: - - a) As a small integer, value 0..255, contained in a single byte. For the -alpha channel the original value is simply value/255. For the color or -luminance channels the value is encoded according to the sRGB specification -and matches the 8-bit format expected by typical display devices. - -The color/gray channels are not scaled (pre-multiplied) by the alpha -channel and are suitable for passing to color management software. - - b) As a value in the range 0..65535, contained in a 2-byte integer, in -the native byte order of the platform on which the application is running. -All channels can be converted to the original value by dividing by 65535; all -channels are linear. Color channels use the RGB encoding (RGB end-points) of -the sRGB specification. This encoding is identified by the -PNG_FORMAT_FLAG_LINEAR flag below. - -When the simplified API needs to convert between sRGB and linear colorspaces, -the actual sRGB transfer curve defined in the sRGB specification (see the -article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 -approximation used elsewhere in libpng. - -When an alpha channel is present it is expected to denote pixel coverage -of the color or luminance channels and is returned as an associated alpha -channel: the color/gray channels are scaled (pre-multiplied) by the alpha -value. - -The samples are either contained directly in the image data, between 1 and 8 -bytes per pixel according to the encoding, or are held in a color-map indexed -by bytes in the image data. In the case of a color-map the color-map entries -are individual samples, encoded as above, and the image data has one byte per -pixel to select the relevant sample from the color-map. - -PNG_FORMAT_* - -The #defines to be used in png_image::format. Each #define identifies a -particular layout of channel data and, if present, alpha values. There are -separate defines for each of the two component encodings. - -A format is built up using single bit flag values. All combinations are -valid. Formats can be built up from the flag values or you can use one of -the predefined values below. When testing formats always use the FORMAT_FLAG -macros to test for individual features - future versions of the library may -add new flags. - -When reading or writing color-mapped images the format should be set to the -format of the entries in the color-map then png_image_{read,write}_colormap -called to read or write the color-map and set the format correctly for the -image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! - -NOTE: libpng can be built with particular features disabled. If you see -compiler errors because the definition of one of the following flags has been -compiled out it is because libpng does not have the required support. It is -possible, however, for the libpng configuration to enable the format on just -read or just write; in that case you may see an error at run time. -You can guard against this by checking for the definition of the -appropriate "_SUPPORTED" macro, one of: - - PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED - - PNG_FORMAT_FLAG_ALPHA format with an alpha channel - PNG_FORMAT_FLAG_COLOR color format: otherwise grayscale - PNG_FORMAT_FLAG_LINEAR 2-byte channels else 1-byte - PNG_FORMAT_FLAG_COLORMAP image data is color-mapped - PNG_FORMAT_FLAG_BGR BGR colors, else order is RGB - PNG_FORMAT_FLAG_AFIRST alpha channel comes first - -Supported formats are as follows. Future versions of libpng may support more -formats; for compatibility with older versions simply check if the format -macro is defined using #ifdef. These defines describe the in-memory layout -of the components of the pixels of the image. - -First the single byte (sRGB) formats: - - PNG_FORMAT_GRAY - PNG_FORMAT_GA - PNG_FORMAT_AG - PNG_FORMAT_RGB - PNG_FORMAT_BGR - PNG_FORMAT_RGBA - PNG_FORMAT_ARGB - PNG_FORMAT_BGRA - PNG_FORMAT_ABGR - -Then the linear 2-byte formats. When naming these "Y" is used to -indicate a luminance (gray) channel. The component order within the pixel -is always the same - there is no provision for swapping the order of the -components in the linear format. The components are 16-bit integers in -the native byte order for your platform, and there is no provision for -swapping the bytes to a different endian condition. - - PNG_FORMAT_LINEAR_Y - PNG_FORMAT_LINEAR_Y_ALPHA - PNG_FORMAT_LINEAR_RGB - PNG_FORMAT_LINEAR_RGB_ALPHA - -With color-mapped formats the image data is one byte for each pixel. The byte -is an index into the color-map which is formatted as above. To obtain a -color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP -to one of the above definitions, or you can use one of the definitions below. - - PNG_FORMAT_RGB_COLORMAP - PNG_FORMAT_BGR_COLORMAP - PNG_FORMAT_RGBA_COLORMAP - PNG_FORMAT_ARGB_COLORMAP - PNG_FORMAT_BGRA_COLORMAP - PNG_FORMAT_ABGR_COLORMAP - -PNG_IMAGE macros - -These are convenience macros to derive information from a png_image -structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the -actual image sample values - either the entries in the color-map or the -pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values -for the pixels and will always return 1 for color-mapped formats. The -remaining macros return information about the rows in the image and the -complete image. - -NOTE: All the macros that take a png_image::format parameter are compile time -constants if the format parameter is, itself, a constant. Therefore these -macros can be used in array declarations and case labels where required. -Similarly the macros are also pre-processor constants (sizeof is not used) so -they can be used in #if tests. - - PNG_IMAGE_SAMPLE_CHANNELS(fmt) - Returns the total number of channels in a given format: 1..4 - - PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt) - Returns the size in bytes of a single component of a pixel or color-map - entry (as appropriate) in the image: 1 or 2. - - PNG_IMAGE_SAMPLE_SIZE(fmt) - This is the size of the sample data for one sample. If the image is - color-mapped it is the size of one color-map entry (and image pixels are - one byte in size), otherwise it is the size of one image pixel. - - PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt) - The maximum size of the color-map required by the format expressed in a - count of components. This can be used to compile-time allocate a - color-map: - - png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; - - png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; - - Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the - information from one of the png_image_begin_read_ APIs and dynamically - allocate the required memory. - - PNG_IMAGE_COLORMAP_SIZE(fmt) - The size of the color-map required by the format; this is the size of the - color-map buffer passed to the png_image_{read,write}_colormap APIs. It is - a fixed number determined by the format so can easily be allocated on the - stack if necessary. - -Corresponding information about the pixels - - PNG_IMAGE_PIXEL_CHANNELS(fmt) - The number of separate channels (components) in a pixel; 1 for a - color-mapped image. - - PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ - The size, in bytes, of each component in a pixel; 1 for a color-mapped - image. - - PNG_IMAGE_PIXEL_SIZE(fmt) - The size, in bytes, of a complete pixel; 1 for a color-mapped image. - -Information about the whole row, or whole image - - PNG_IMAGE_ROW_STRIDE(image) - Returns the total number of components in a single row of the image; this - is the minimum 'row stride', the minimum count of components between each - row. For a color-mapped image this is the minimum number of bytes in a - row. - - If you need the stride measured in bytes, row_stride_bytes is - PNG_IMAGE_ROW_STRIDE(image) * PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt) - plus any padding bytes that your application might need, for example - to start the next row on a 4-byte boundary. - - PNG_IMAGE_BUFFER_SIZE(image, row_stride) - Return the size, in bytes, of an image buffer given a png_image and a row - stride - the number of components to leave space for in each row. - - PNG_IMAGE_SIZE(image) - Return the size, in bytes, of the image in memory given just a png_image; - the row stride is the minimum stride required for the image. - - PNG_IMAGE_COLORMAP_SIZE(image) - Return the size, in bytes, of the color-map of this image. If the image - format is not a color-map format this will return a size sufficient for - 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if - you don't want to allocate a color-map in this case. - -PNG_IMAGE_FLAG_* - -Flags containing additional information about the image are held in -the 'flags' field of png_image. - - PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB == 0x01 - This indicates the the RGB values of the in-memory bitmap do not - correspond to the red, green and blue end-points defined by sRGB. - - PNG_IMAGE_FLAG_FAST == 0x02 - On write emphasise speed over compression; the resultant PNG file will be - larger but will be produced significantly faster, particular for large - images. Do not use this option for images which will be distributed, only - used it when producing intermediate files that will be read back in - repeatedly. For a typical 24-bit image the option will double the read - speed at the cost of increasing the image size by 25%, however for many - more compressible images the PNG file can be 10 times larger with only a - slight speed gain. - - PNG_IMAGE_FLAG_16BIT_sRGB == 0x04 - On read if the image is a 16-bit per component image and there is no gAMA - or sRGB chunk assume that the components are sRGB encoded. Notice that - images output by the simplified API always have gamma information; setting - this flag only affects the interpretation of 16-bit images from an - external source. It is recommended that the application expose this flag - to the user; the user can normally easily recognize the difference between - linear and sRGB encoding. This flag has no effect on write - the data - passed to the write APIs must have the correct encoding (as defined - above.) - - If the flag is not set (the default) input 16-bit per component data is - assumed to be linear. - - NOTE: the flag can only be set after the png_image_begin_read_ call, - because that call initializes the 'flags' field. - -READ APIs - - The png_image passed to the read APIs must have been initialized by setting - the png_controlp field 'opaque' to NULL (or, better, memset the whole thing.) - - int png_image_begin_read_from_file( png_imagep image, - const char *file_name) - - The named file is opened for read and the image header - is filled in from the PNG header in the file. - - int png_image_begin_read_from_stdio (png_imagep image, - FILE* file) - - The PNG header is read from the stdio FILE object. - - int png_image_begin_read_from_memory(png_imagep image, - png_const_voidp memory, png_size_t size) - - The PNG header is read from the given memory buffer. - - int png_image_finish_read(png_imagep image, - png_colorp background, void *buffer, - png_int_32 row_stride, void *colormap)); - - Finish reading the image into the supplied buffer and - clean up the png_image structure. - - row_stride is the step, in png_byte or png_uint_16 units - as appropriate, between adjacent rows. A positive stride - indicates that the top-most row is first in the buffer - - the normal top-down arrangement. A negative stride - indicates that the bottom-most row is first in the buffer. - - background need only be supplied if an alpha channel must - be removed from a png_byte format and the removal is to be - done by compositing on a solid color; otherwise it may be - NULL and any composition will be done directly onto the - buffer. The value is an sRGB color to use for the - background, for grayscale output the green channel is used. - - For linear output removing the alpha channel is always done - by compositing on black. - - void png_image_free(png_imagep image) - - Free any data allocated by libpng in image->opaque, - setting the pointer to NULL. May be called at any time - after the structure is initialized. - -When the simplified API needs to convert between sRGB and linear colorspaces, -the actual sRGB transfer curve defined in the sRGB specification (see the -article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 -approximation used elsewhere in libpng. - -WRITE APIS - -For write you must initialize a png_image structure to describe the image to -be written: - - version: must be set to PNG_IMAGE_VERSION - opaque: must be initialized to NULL - width: image width in pixels - height: image height in rows - format: the format of the data you wish to write - flags: set to 0 unless one of the defined flags applies; set - PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images - where the RGB values do not correspond to the colors in sRGB. - colormap_entries: set to the number of entries in the color-map (0 to 256) - - int png_image_write_to_file, (png_imagep image, - const char *file, int convert_to_8bit, const void *buffer, - png_int_32 row_stride, const void *colormap)); - - Write the image to the named file. - - int png_image_write_to_memory (png_imagep image, void *memory, - png_alloc_size_t * PNG_RESTRICT memory_bytes, - int convert_to_8_bit, const void *buffer, ptrdiff_t row_stride, - const void *colormap)); - - Write the image to memory. - - int png_image_write_to_stdio(png_imagep image, FILE *file, - int convert_to_8_bit, const void *buffer, - png_int_32 row_stride, const void *colormap) - - Write the image to the given (FILE*). - -With all write APIs if image is in one of the linear formats with -(png_uint_16) data then setting convert_to_8_bit will cause the output to be -a (png_byte) PNG gamma encoded according to the sRGB specification, otherwise -a 16-bit linear encoded PNG file is written. - -With all APIs row_stride is handled as in the read APIs - it is the spacing -from one row to the next in component sized units (float) and if negative -indicates a bottom-up row layout in the buffer. If you pass zero, libpng will -calculate the row_stride for you from the width and number of channels. - -Note that the write API does not support interlacing, sub-8-bit pixels, -indexed (paletted) images, or most ancillary chunks. - -VI. Modifying/Customizing libpng - -There are two issues here. The first is changing how libpng does -standard things like memory allocation, input/output, and error handling. -The second deals with more complicated things like adding new chunks, -adding new transformations, and generally changing how libpng works. -Both of those are compile-time issues; that is, they are generally -determined at the time the code is written, and there is rarely a need -to provide the user with a means of changing them. - -Memory allocation, input/output, and error handling - -All of the memory allocation, input/output, and error handling in libpng -goes through callbacks that are user-settable. The default routines are -in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively. To change -these functions, call the appropriate png_set_*_fn() function. - -Memory allocation is done through the functions png_malloc(), png_calloc(), -and png_free(). The png_malloc() and png_free() functions currently just -call the standard C functions and png_calloc() calls png_malloc() and then -clears the newly allocated memory to zero; note that png_calloc(png_ptr, size) -is not the same as the calloc(number, size) function provided by stdlib.h. -There is limited support for certain systems with segmented memory -architectures and the types of pointers declared by png.h match this; you -will have to use appropriate pointers in your application. If you prefer -to use a different method of allocating and freeing data, you can use -png_create_read_struct_2() or png_create_write_struct_2() to register your -own functions as described above. These functions also provide a void -pointer that can be retrieved via - - mem_ptr=png_get_mem_ptr(png_ptr); - -Your replacement memory functions must have prototypes as follows: - - png_voidp malloc_fn(png_structp png_ptr, - png_alloc_size_t size); - - void free_fn(png_structp png_ptr, png_voidp ptr); - -Your malloc_fn() must return NULL in case of failure. The png_malloc() -function will normally call png_error() if it receives a NULL from the -system memory allocator or from your replacement malloc_fn(). - -Your free_fn() will never be called with a NULL ptr, since libpng's -png_free() checks for NULL before calling free_fn(). - -Input/Output in libpng is done through png_read() and png_write(), -which currently just call fread() and fwrite(). The FILE * is stored in -png_struct and is initialized via png_init_io(). If you wish to change -the method of I/O, the library supplies callbacks that you can set -through the function png_set_read_fn() and png_set_write_fn() at run -time, instead of calling the png_init_io() function. These functions -also provide a void pointer that can be retrieved via the function -png_get_io_ptr(). For example: - - png_set_read_fn(png_structp read_ptr, - voidp read_io_ptr, png_rw_ptr read_data_fn) - - png_set_write_fn(png_structp write_ptr, - voidp write_io_ptr, png_rw_ptr write_data_fn, - png_flush_ptr output_flush_fn); - - voidp read_io_ptr = png_get_io_ptr(read_ptr); - voidp write_io_ptr = png_get_io_ptr(write_ptr); - -The replacement I/O functions must have prototypes as follows: - - void user_read_data(png_structp png_ptr, - png_bytep data, png_size_t length); - - void user_write_data(png_structp png_ptr, - png_bytep data, png_size_t length); - - void user_flush_data(png_structp png_ptr); - -The user_read_data() function is responsible for detecting and -handling end-of-data errors. - -Supplying NULL for the read, write, or flush functions sets them back -to using the default C stream functions, which expect the io_ptr to -point to a standard *FILE structure. It is probably a mistake -to use NULL for one of write_data_fn and output_flush_fn but not both -of them, unless you have built libpng with PNG_NO_WRITE_FLUSH defined. -It is an error to read from a write stream, and vice versa. - -Error handling in libpng is done through png_error() and png_warning(). -Errors handled through png_error() are fatal, meaning that png_error() -should never return to its caller. Currently, this is handled via -setjmp() and longjmp() (unless you have compiled libpng with -PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()), -but you could change this to do things like exit() if you should wish, -as long as your function does not return. - -On non-fatal errors, png_warning() is called -to print a warning message, and then control returns to the calling code. -By default png_error() and png_warning() print a message on stderr via -fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined -(because you don't want the messages) or PNG_NO_STDIO defined (because -fprintf() isn't available). If you wish to change the behavior of the error -functions, you will need to set up your own message callbacks. These -functions are normally supplied at the time that the png_struct is created. -It is also possible to redirect errors and warnings to your own replacement -functions after png_create_*_struct() has been called by calling: - - png_set_error_fn(png_structp png_ptr, - png_voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warning_fn); - - png_voidp error_ptr = png_get_error_ptr(png_ptr); - -If NULL is supplied for either error_fn or warning_fn, then the libpng -default function will be used, calling fprintf() and/or longjmp() if a -problem is encountered. The replacement error functions should have -parameters as follows: - - void user_error_fn(png_structp png_ptr, - png_const_charp error_msg); - - void user_warning_fn(png_structp png_ptr, - png_const_charp warning_msg); - -The motivation behind using setjmp() and longjmp() is the C++ throw and -catch exception handling methods. This makes the code much easier to write, -as there is no need to check every return code of every function call. -However, there are some uncertainties about the status of local variables -after a longjmp, so the user may want to be careful about doing anything -after setjmp returns non-zero besides returning itself. Consult your -compiler documentation for more details. For an alternative approach, you -may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net), -which is illustrated in pngvalid.c and in contrib/visupng. - -Beginning in libpng-1.4.0, the png_set_benign_errors() API became available. -You can use this to handle certain errors (normally handled as errors) -as warnings. - - png_set_benign_errors (png_ptr, int allowed); - - allowed: 0: treat png_benign_error() as an error. - 1: treat png_benign_error() as a warning. - -As of libpng-1.6.0, the default condition is to treat benign errors as -warnings while reading and as errors while writing. - -Custom chunks - -If you need to read or write custom chunks, you may need to get deeper -into the libpng code. The library now has mechanisms for storing -and writing chunks of unknown type; you can even declare callbacks -for custom chunks. However, this may not be good enough if the -library code itself needs to know about interactions between your -chunk and existing `intrinsic' chunks. - -If you need to write a new intrinsic chunk, first read the PNG -specification. Acquire a first level of understanding of how it works. -Pay particular attention to the sections that describe chunk names, -and look at how other chunks were designed, so you can do things -similarly. Second, check out the sections of libpng that read and -write chunks. Try to find a chunk that is similar to yours and use -it as a template. More details can be found in the comments inside -the code. It is best to handle private or unknown chunks in a generic method, -via callback functions, instead of by modifying libpng functions. This -is illustrated in pngtest.c, which uses a callback function to handle a -private "vpAg" chunk and the new "sTER" chunk, which are both unknown to -libpng. - -If you wish to write your own transformation for the data, look through -the part of the code that does the transformations, and check out some of -the simpler ones to get an idea of how they work. Try to find a similar -transformation to the one you want to add and copy off of it. More details -can be found in the comments inside the code itself. - -Configuring for gui/windowing platforms: - -You will need to write new error and warning functions that use the GUI -interface, as described previously, and set them to be the error and -warning functions at the time that png_create_*_struct() is called, -in order to have them available during the structure initialization. -They can be changed later via png_set_error_fn(). On some compilers, -you may also have to change the memory allocators (png_malloc, etc.). - -Configuring zlib: - -There are special functions to configure the compression. Perhaps the -most useful one changes the compression level, which currently uses -input compression values in the range 0 - 9. The library normally -uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests -have shown that for a large majority of images, compression values in -the range 3-6 compress nearly as well as higher levels, and do so much -faster. For online applications it may be desirable to have maximum speed -(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also -specify no compression (Z_NO_COMPRESSION = 0), but this would create -files larger than just storing the raw bitmap. You can specify the -compression level by calling: - - #include zlib.h - png_set_compression_level(png_ptr, level); - -Another useful one is to reduce the memory level used by the library. -The memory level defaults to 8, but it can be lowered if you are -short on memory (running DOS, for example, where you only have 640K). -Note that the memory level does have an effect on compression; among -other things, lower levels will result in sections of incompressible -data being emitted in smaller stored blocks, with a correspondingly -larger relative overhead of up to 15% in the worst case. - - #include zlib.h - png_set_compression_mem_level(png_ptr, level); - -The other functions are for configuring zlib. They are not recommended -for normal use and may result in writing an invalid PNG file. See -zlib.h for more information on what these mean. - - #include zlib.h - png_set_compression_strategy(png_ptr, - strategy); - - png_set_compression_window_bits(png_ptr, - window_bits); - - png_set_compression_method(png_ptr, method); - -This controls the size of the IDAT chunks (default 8192): - - png_set_compression_buffer_size(png_ptr, size); - -As of libpng version 1.5.4, additional APIs became -available to set these separately for non-IDAT -compressed chunks such as zTXt, iTXt, and iCCP: - - #include zlib.h - #if PNG_LIBPNG_VER >= 10504 - png_set_text_compression_level(png_ptr, level); - - png_set_text_compression_mem_level(png_ptr, level); - - png_set_text_compression_strategy(png_ptr, - strategy); - - png_set_text_compression_window_bits(png_ptr, - window_bits); - - png_set_text_compression_method(png_ptr, method); - #endif - -Controlling row filtering - -If you want to control whether libpng uses filtering or not, which -filters are used, and how it goes about picking row filters, you -can call one of these functions. The selection and configuration -of row filters can have a significant impact on the size and -encoding speed and a somewhat lesser impact on the decoding speed -of an image. Filtering is enabled by default for RGB and grayscale -images (with and without alpha), but not for paletted images nor -for any images with bit depths less than 8 bits/pixel. - -The 'method' parameter sets the main filtering method, which is -currently only '0' in the PNG 1.2 specification. The 'filters' -parameter sets which filter(s), if any, should be used for each -scanline. Possible values are PNG_ALL_FILTERS, PNG_NO_FILTERS, -or PNG_FAST_FILTERS to turn filtering on and off, or to turn on -just the fast-decoding subset of filters, respectively. - -Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB, -PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise -ORed together with '|' to specify one or more filters to use. -These filters are described in more detail in the PNG specification. -If you intend to change the filter type during the course of writing -the image, you should start with flags set for all of the filters -you intend to use so that libpng can initialize its internal -structures appropriately for all of the filter types. (Note that this -means the first row must always be adaptively filtered, because libpng -currently does not allocate the filter buffers until png_write_row() -is called for the first time.) - - filters = PNG_NO_FILTERS; - filters = PNG_ALL_FILTERS; - filters = PNG_FAST_FILTERS; - - or - - filters = PNG_FILTER_NONE | PNG_FILTER_SUB | - PNG_FILTER_UP | PNG_FILTER_AVG | - PNG_FILTER_PAETH; - - png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, - filters); - - The second parameter can also be - PNG_INTRAPIXEL_DIFFERENCING if you are - writing a PNG to be embedded in a MNG - datastream. This parameter must be the - same as the value of filter_method used - in png_set_IHDR(). - -Requesting debug printout - -The macro definition PNG_DEBUG can be used to request debugging -printout. Set it to an integer value in the range 0 to 3. Higher -numbers result in increasing amounts of debugging information. The -information is printed to the "stderr" file, unless another file -name is specified in the PNG_DEBUG_FILE macro definition. - -When PNG_DEBUG > 0, the following functions (macros) become available: - - png_debug(level, message) - png_debug1(level, message, p1) - png_debug2(level, message, p1, p2) - -in which "level" is compared to PNG_DEBUG to decide whether to print -the message, "message" is the formatted string to be printed, -and p1 and p2 are parameters that are to be embedded in the string -according to printf-style formatting directives. For example, - - png_debug1(2, "foo=%d", foo); - -is expanded to - - if (PNG_DEBUG > 2) - fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo); - -When PNG_DEBUG is defined but is zero, the macros aren't defined, but you -can still use PNG_DEBUG to control your own debugging: - - #ifdef PNG_DEBUG - fprintf(stderr, ... - #endif - -When PNG_DEBUG = 1, the macros are defined, but only png_debug statements -having level = 0 will be printed. There aren't any such statements in -this version of libpng, but if you insert some they will be printed. - -VII. MNG support - -The MNG specification (available at http://www.libpng.org/pub/mng) allows -certain extensions to PNG for PNG images that are embedded in MNG datastreams. -Libpng can support some of these extensions. To enable them, use the -png_permit_mng_features() function: - - feature_set = png_permit_mng_features(png_ptr, mask) - - mask is a png_uint_32 containing the bitwise OR of the - features you want to enable. These include - PNG_FLAG_MNG_EMPTY_PLTE - PNG_FLAG_MNG_FILTER_64 - PNG_ALL_MNG_FEATURES - - feature_set is a png_uint_32 that is the bitwise AND of - your mask with the set of MNG features that is - supported by the version of libpng that you are using. - -It is an error to use this function when reading or writing a standalone -PNG file with the PNG 8-byte signature. The PNG datastream must be wrapped -in a MNG datastream. As a minimum, it must have the MNG 8-byte signature -and the MHDR and MEND chunks. Libpng does not provide support for these -or any other MNG chunks; your application must provide its own support for -them. You may wish to consider using libmng (available at -http://www.libmng.com) instead. - -VIII. Changes to Libpng from version 0.88 - -It should be noted that versions of libpng later than 0.96 are not -distributed by the original libpng author, Guy Schalnat, nor by -Andreas Dilger, who had taken over from Guy during 1996 and 1997, and -distributed versions 0.89 through 0.96, but rather by another member -of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are -still alive and well, but they have moved on to other things. - -The old libpng functions png_read_init(), png_write_init(), -png_info_init(), png_read_destroy(), and png_write_destroy() have been -moved to PNG_INTERNAL in version 0.95 to discourage their use. These -functions will be removed from libpng version 1.4.0. - -The preferred method of creating and initializing the libpng structures is -via the png_create_read_struct(), png_create_write_struct(), and -png_create_info_struct() because they isolate the size of the structures -from the application, allow version error checking, and also allow the -use of custom error handling routines during the initialization, which -the old functions do not. The functions png_read_destroy() and -png_write_destroy() do not actually free the memory that libpng -allocated for these structs, but just reset the data structures, so they -can be used instead of png_destroy_read_struct() and -png_destroy_write_struct() if you feel there is too much system overhead -allocating and freeing the png_struct for each image read. - -Setting the error callbacks via png_set_message_fn() before -png_read_init() as was suggested in libpng-0.88 is no longer supported -because this caused applications that do not use custom error functions -to fail if the png_ptr was not initialized to zero. It is still possible -to set the error callbacks AFTER png_read_init(), or to change them with -png_set_error_fn(), which is essentially the same function, but with a new -name to force compilation errors with applications that try to use the old -method. - -Support for the sCAL, iCCP, iTXt, and sPLT chunks was added at libpng-1.0.6; -however, iTXt support was not enabled by default. - -Starting with version 1.0.7, you can find out which version of the library -you are using at run-time: - - png_uint_32 libpng_vn = png_access_version_number(); - -The number libpng_vn is constructed from the major version, minor -version with leading zero, and release number with leading zero, -(e.g., libpng_vn for version 1.0.7 is 10007). - -Note that this function does not take a png_ptr, so you can call it -before you've created one. - -You can also check which version of png.h you used when compiling your -application: - - png_uint_32 application_vn = PNG_LIBPNG_VER; - -IX. Changes to Libpng from version 1.0.x to 1.2.x - -Support for user memory management was enabled by default. To -accomplish this, the functions png_create_read_struct_2(), -png_create_write_struct_2(), png_set_mem_fn(), png_get_mem_ptr(), -png_malloc_default(), and png_free_default() were added. - -Support for the iTXt chunk has been enabled by default as of -version 1.2.41. - -Support for certain MNG features was enabled. - -Support for numbered error messages was added. However, we never got -around to actually numbering the error messages. The function -png_set_strip_error_numbers() was added (Note: the prototype for this -function was inadvertently removed from png.h in PNG_NO_ASSEMBLER_CODE -builds of libpng-1.2.15. It was restored in libpng-1.2.36). - -The png_malloc_warn() function was added at libpng-1.2.3. This issues -a png_warning and returns NULL instead of aborting when it fails to -acquire the requested memory allocation. - -Support for setting user limits on image width and height was enabled -by default. The functions png_set_user_limits(), png_get_user_width_max(), -and png_get_user_height_max() were added at libpng-1.2.6. - -The png_set_add_alpha() function was added at libpng-1.2.7. - -The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9. -Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the -tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is -deprecated. - -A number of macro definitions in support of runtime selection of -assembler code features (especially Intel MMX code support) were -added at libpng-1.2.0: - - PNG_ASM_FLAG_MMX_SUPPORT_COMPILED - PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU - PNG_ASM_FLAG_MMX_READ_COMBINE_ROW - PNG_ASM_FLAG_MMX_READ_INTERLACE - PNG_ASM_FLAG_MMX_READ_FILTER_SUB - PNG_ASM_FLAG_MMX_READ_FILTER_UP - PNG_ASM_FLAG_MMX_READ_FILTER_AVG - PNG_ASM_FLAG_MMX_READ_FILTER_PAETH - PNG_ASM_FLAGS_INITIALIZED - PNG_MMX_READ_FLAGS - PNG_MMX_FLAGS - PNG_MMX_WRITE_FLAGS - PNG_MMX_FLAGS - -We added the following functions in support of runtime -selection of assembler code features: - - png_get_mmx_flagmask() - png_set_mmx_thresholds() - png_get_asm_flags() - png_get_mmx_bitdepth_threshold() - png_get_mmx_rowbytes_threshold() - png_set_asm_flags() - -We replaced all of these functions with simple stubs in libpng-1.2.20, -when the Intel assembler code was removed due to a licensing issue. - -These macros are deprecated: - - PNG_READ_TRANSFORMS_NOT_SUPPORTED - PNG_PROGRESSIVE_READ_NOT_SUPPORTED - PNG_NO_SEQUENTIAL_READ_SUPPORTED - PNG_WRITE_TRANSFORMS_NOT_SUPPORTED - PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED - PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED - -They have been replaced, respectively, by: - - PNG_NO_READ_TRANSFORMS - PNG_NO_PROGRESSIVE_READ - PNG_NO_SEQUENTIAL_READ - PNG_NO_WRITE_TRANSFORMS - PNG_NO_READ_ANCILLARY_CHUNKS - PNG_NO_WRITE_ANCILLARY_CHUNKS - -PNG_MAX_UINT was replaced with PNG_UINT_31_MAX. It has been -deprecated since libpng-1.0.16 and libpng-1.2.6. - -The function - png_check_sig(sig, num) -was replaced with - !png_sig_cmp(sig, 0, num) -It has been deprecated since libpng-0.90. - -The function - png_set_gray_1_2_4_to_8() -which also expands tRNS to alpha was replaced with - png_set_expand_gray_1_2_4_to_8() -which does not. It has been deprecated since libpng-1.0.18 and 1.2.9. - -X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x - -Private libpng prototypes and macro definitions were moved from -png.h and pngconf.h into a new pngpriv.h header file. - -Functions png_set_benign_errors(), png_benign_error(), and -png_chunk_benign_error() were added. - -Support for setting the maximum amount of memory that the application -will allocate for reading chunks was added, as a security measure. -The functions png_set_chunk_cache_max() and png_get_chunk_cache_max() -were added to the library. - -We implemented support for I/O states by adding png_ptr member io_state -and functions png_get_io_chunk_name() and png_get_io_state() in pngget.c - -We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level -input transforms. - -Checking for and reporting of errors in the IHDR chunk is more thorough. - -Support for global arrays was removed, to improve thread safety. - -Some obsolete/deprecated macros and functions have been removed. - -Typecasted NULL definitions such as - #define png_voidp_NULL (png_voidp)NULL -were eliminated. If you used these in your application, just use -NULL instead. - -The png_struct and info_struct members "trans" and "trans_values" were -changed to "trans_alpha" and "trans_color", respectively. - -The obsolete, unused pnggccrd.c and pngvcrd.c files and related makefiles -were removed. - -The PNG_1_0_X and PNG_1_2_X macros were eliminated. - -The PNG_LEGACY_SUPPORTED macro was eliminated. - -Many WIN32_WCE #ifdefs were removed. - -The functions png_read_init(info_ptr), png_write_init(info_ptr), -png_info_init(info_ptr), png_read_destroy(), and png_write_destroy() -have been removed. They have been deprecated since libpng-0.95. - -The png_permit_empty_plte() was removed. It has been deprecated -since libpng-1.0.9. Use png_permit_mng_features() instead. - -We removed the obsolete stub functions png_get_mmx_flagmask(), -png_set_mmx_thresholds(), png_get_asm_flags(), -png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(), -png_set_asm_flags(), and png_mmx_supported() - -We removed the obsolete png_check_sig(), png_memcpy_check(), and -png_memset_check() functions. Instead use !png_sig_cmp(), memcpy(), -and memset(), respectively. - -The function png_set_gray_1_2_4_to_8() was removed. It has been -deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with -png_set_expand_gray_1_2_4_to_8() because the former function also -expanded any tRNS chunk to an alpha channel. - -Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32 -were added and are used by default instead of the corresponding -functions. Unfortunately, -from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the -function) incorrectly returned a value of type png_uint_32. - -We changed the prototype for png_malloc() from - png_malloc(png_structp png_ptr, png_uint_32 size) -to - png_malloc(png_structp png_ptr, png_alloc_size_t size) - -This also applies to the prototype for the user replacement malloc_fn(). - -The png_calloc() function was added and is used in place of -of "png_malloc(); memset();" except in the case in png_read_png() -where the array consists of pointers; in this case a "for" loop is used -after the png_malloc() to set the pointers to NULL, to give robust. -behavior in case the application runs out of memory part-way through -the process. - -We changed the prototypes of png_get_compression_buffer_size() and -png_set_compression_buffer_size() to work with png_size_t instead of -png_uint_32. - -Support for numbered error messages was removed by default, since we -never got around to actually numbering the error messages. The function -png_set_strip_error_numbers() was removed from the library by default. - -The png_zalloc() and png_zfree() functions are no longer exported. -The png_zalloc() function no longer zeroes out the memory that it -allocates. Applications that called png_zalloc(png_ptr, number, size) -can call png_calloc(png_ptr, number*size) instead, and can call -png_free() instead of png_zfree(). - -Support for dithering was disabled by default in libpng-1.4.0, because -it has not been well tested and doesn't actually "dither". -The code was not -removed, however, and could be enabled by building libpng with -PNG_READ_DITHER_SUPPORTED defined. In libpng-1.4.2, this support -was re-enabled, but the function was renamed png_set_quantize() to -reflect more accurately what it actually does. At the same time, -the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to -PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED -was renamed to PNG_READ_QUANTIZE_SUPPORTED. - -We removed the trailing '.' from the warning and error messages. - -XI. Changes to Libpng from version 1.4.x to 1.5.x - -From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the -function) incorrectly returned a value of type png_uint_32. -The incorrect macro was removed from libpng-1.4.5. - -Checking for invalid palette index on write was added at libpng -1.5.10. If a pixel contains an invalid (out-of-range) index libpng issues -a benign error. This is enabled by default because this condition is an -error according to the PNG specification, Clause 11.3.2, but the error can -be ignored in each png_ptr with - - png_set_check_for_invalid_index(png_ptr, allowed); - - allowed - one of - 0: disable benign error (accept the - invalid data without warning). - 1: enable benign error (treat the - invalid data as an error or a - warning). - -If the error is ignored, or if png_benign_error() treats it as a warning, -any invalid pixels are decoded as opaque black by the decoder and written -as-is by the encoder. - -Retrieving the maximum palette index found was added at libpng-1.5.15. -This statement must appear after png_read_png() or png_read_image() while -reading, and after png_write_png() or png_write_image() while writing. - - int max_palette = png_get_palette_max(png_ptr, info_ptr); - -This will return the maximum palette index found in the image, or "-1" if -the palette was not checked, or "0" if no palette was found. Note that this -does not account for any palette index used by ancillary chunks such as the -bKGD chunk; you must check those separately to determine the maximum -palette index actually used. - -There are no substantial API changes between the non-deprecated parts of -the 1.4.5 API and the 1.5.0 API; however, the ability to directly access -members of the main libpng control structures, png_struct and png_info, -deprecated in earlier versions of libpng, has been completely removed from -libpng 1.5, and new private "pngstruct.h", "pnginfo.h", and "pngdebug.h" -header files were created. - -We no longer include zlib.h in png.h. The include statement has been moved -to pngstruct.h, where it is not accessible by applications. Applications that -need access to information in zlib.h will need to add the '#include "zlib.h"' -directive. It does not matter whether this is placed prior to or after -the '"#include png.h"' directive. - -The png_sprintf(), png_strcpy(), and png_strncpy() macros are no longer used -and were removed. - -We moved the png_strlen(), png_memcpy(), png_memset(), and png_memcmp() -macros into a private header file (pngpriv.h) that is not accessible to -applications. - -In png_get_iCCP, the type of "profile" was changed from png_charpp -to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep. - -There are changes of form in png.h, including new and changed macros to -declare parts of the API. Some API functions with arguments that are -pointers to data not modified within the function have been corrected to -declare these arguments with PNG_CONST. - -Much of the internal use of C macros to control the library build has also -changed and some of this is visible in the exported header files, in -particular the use of macros to control data and API elements visible -during application compilation may require significant revision to -application code. (It is extremely rare for an application to do this.) - -Any program that compiled against libpng 1.4 and did not use deprecated -features or access internal library structures should compile and work -against libpng 1.5, except for the change in the prototype for -png_get_iCCP() and png_set_iCCP() API functions mentioned above. - -libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of -interlaced images. The macros return the number of rows and columns in -each pass and information that can be used to de-interlace and (if -absolutely necessary) interlace an image. - -libpng 1.5.0 adds an API png_longjmp(png_ptr, value). This API calls -the application-provided png_longjmp_ptr on the internal, but application -initialized, longjmp buffer. It is provided as a convenience to avoid -the need to use the png_jmpbuf macro, which had the unnecessary side -effect of resetting the internal png_longjmp_ptr value. - -libpng 1.5.0 includes a complete fixed point API. By default this is -present along with the corresponding floating point API. In general the -fixed point API is faster and smaller than the floating point one because -the PNG file format used fixed point, not floating point. This applies -even if the library uses floating point in internal calculations. A new -macro, PNG_FLOATING_ARITHMETIC_SUPPORTED, reveals whether the library -uses floating point arithmetic (the default) or fixed point arithmetic -internally for performance critical calculations such as gamma correction. -In some cases, the gamma calculations may produce slightly different -results. This has changed the results in png_rgb_to_gray and in alpha -composition (png_set_background for example). This applies even if the -original image was already linear (gamma == 1.0) and, therefore, it is -not necessary to linearize the image. This is because libpng has *not* -been changed to optimize that case correctly, yet. - -Fixed point support for the sCAL chunk comes with an important caveat; -the sCAL specification uses a decimal encoding of floating point values -and the accuracy of PNG fixed point values is insufficient for -representation of these values. Consequently a "string" API -(png_get_sCAL_s and png_set_sCAL_s) is the only reliable way of reading -arbitrary sCAL chunks in the absence of either the floating point API or -internal floating point calculations. Starting with libpng-1.5.0, both -of these functions are present when PNG_sCAL_SUPPORTED is defined. Prior -to libpng-1.5.0, their presence also depended upon PNG_FIXED_POINT_SUPPORTED -being defined and PNG_FLOATING_POINT_SUPPORTED not being defined. - -Applications no longer need to include the optional distribution header -file pngusr.h or define the corresponding macros during application -build in order to see the correct variant of the libpng API. From 1.5.0 -application code can check for the corresponding _SUPPORTED macro: - -#ifdef PNG_INCH_CONVERSIONS_SUPPORTED - /* code that uses the inch conversion APIs. */ -#endif - -This macro will only be defined if the inch conversion functions have been -compiled into libpng. The full set of macros, and whether or not support -has been compiled in, are available in the header file pnglibconf.h. -This header file is specific to the libpng build. Notice that prior to -1.5.0 the _SUPPORTED macros would always have the default definition unless -reset by pngusr.h or by explicit settings on the compiler command line. -These settings may produce compiler warnings or errors in 1.5.0 because -of macro redefinition. - -Applications can now choose whether to use these macros or to call the -corresponding function by defining PNG_USE_READ_MACROS or -PNG_NO_USE_READ_MACROS before including png.h. Notice that this is -only supported from 1.5.0; defining PNG_NO_USE_READ_MACROS prior to 1.5.0 -will lead to a link failure. - -Prior to libpng-1.5.4, the zlib compressor used the same set of parameters -when compressing the IDAT data and textual data such as zTXt and iCCP. -In libpng-1.5.4 we reinitialized the zlib stream for each type of data. -We added five png_set_text_*() functions for setting the parameters to -use with textual data. - -Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED -option was off by default, and slightly inaccurate scaling occurred. -This option can no longer be turned off, and the choice of accurate -or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8() -API for accurate scaling or the old png_set_strip_16_to_8() API for simple -chopping. In libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED -macro became PNG_READ_SCALE_16_TO_8_SUPPORTED, and the PNG_READ_16_TO_8 -macro became PNG_READ_STRIP_16_TO_8_SUPPORTED, to enable the two -png_set_*_16_to_8() functions separately. - -Prior to libpng-1.5.4, the png_set_user_limits() function could only be -used to reduce the width and height limits from the value of -PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said -that it could be used to override them. Now this function will reduce or -increase the limits. - -Starting in libpng-1.5.10, the user limits can be set en masse with the -configuration option PNG_SAFE_LIMITS_SUPPORTED. If this option is enabled, -a set of "safe" limits is applied in pngpriv.h. These can be overridden by -application calls to png_set_user_limits(), png_set_user_chunk_cache_max(), -and/or png_set_user_malloc_max() that increase or decrease the limits. Also, -in libpng-1.5.10 the default width and height limits were increased -from 1,000,000 to 0x7fffffff (i.e., made unlimited). Therefore, the -limits are now - default safe - png_user_width_max 0x7fffffff 1,000,000 - png_user_height_max 0x7fffffff 1,000,000 - png_user_chunk_cache_max 0 (unlimited) 128 - png_user_chunk_malloc_max 0 (unlimited) 8,000,000 - -The png_set_option() function (and the "options" member of the png struct) was -added to libpng-1.5.15, with option PNG_ARM_NEON. - -The library now supports a complete fixed point implementation and can -thus be used on systems that have no floating point support or very -limited or slow support. Previously gamma correction, an essential part -of complete PNG support, required reasonably fast floating point. - -As part of this the choice of internal implementation has been made -independent of the choice of fixed versus floating point APIs and all the -missing fixed point APIs have been implemented. - -The exact mechanism used to control attributes of API functions has -changed, as described in the INSTALL file. - -A new test program, pngvalid, is provided in addition to pngtest. -pngvalid validates the arithmetic accuracy of the gamma correction -calculations and includes a number of validations of the file format. -A subset of the full range of tests is run when "make check" is done -(in the 'configure' build.) pngvalid also allows total allocated memory -usage to be evaluated and performs additional memory overwrite validation. - -Many changes to individual feature macros have been made. The following -are the changes most likely to be noticed by library builders who -configure libpng: - -1) All feature macros now have consistent naming: - -#define PNG_NO_feature turns the feature off -#define PNG_feature_SUPPORTED turns the feature on - -pnglibconf.h contains one line for each feature macro which is either: - -#define PNG_feature_SUPPORTED - -if the feature is supported or: - -/*#undef PNG_feature_SUPPORTED*/ - -if it is not. Library code consistently checks for the 'SUPPORTED' macro. -It does not, and libpng applications should not, check for the 'NO' macro -which will not normally be defined even if the feature is not supported. -The 'NO' macros are only used internally for setting or not setting the -corresponding 'SUPPORTED' macros. - -Compatibility with the old names is provided as follows: - -PNG_INCH_CONVERSIONS turns on PNG_INCH_CONVERSIONS_SUPPORTED - -And the following definitions disable the corresponding feature: - -PNG_SETJMP_NOT_SUPPORTED disables SETJMP -PNG_READ_TRANSFORMS_NOT_SUPPORTED disables READ_TRANSFORMS -PNG_NO_READ_COMPOSITED_NODIV disables READ_COMPOSITE_NODIV -PNG_WRITE_TRANSFORMS_NOT_SUPPORTED disables WRITE_TRANSFORMS -PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED disables READ_ANCILLARY_CHUNKS -PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED disables WRITE_ANCILLARY_CHUNKS - -Library builders should remove use of the above, inconsistent, names. - -2) Warning and error message formatting was previously conditional on -the STDIO feature. The library has been changed to use the -CONSOLE_IO feature instead. This means that if CONSOLE_IO is disabled -the library no longer uses the printf(3) functions, even though the -default read/write implementations use (FILE) style stdio.h functions. - -3) Three feature macros now control the fixed/floating point decisions: - -PNG_FLOATING_POINT_SUPPORTED enables the floating point APIs - -PNG_FIXED_POINT_SUPPORTED enables the fixed point APIs; however, in -practice these are normally required internally anyway (because the PNG -file format is fixed point), therefore in most cases PNG_NO_FIXED_POINT -merely stops the function from being exported. - -PNG_FLOATING_ARITHMETIC_SUPPORTED chooses between the internal floating -point implementation or the fixed point one. Typically the fixed point -implementation is larger and slower than the floating point implementation -on a system that supports floating point; however, it may be faster on a -system which lacks floating point hardware and therefore uses a software -emulation. - -4) Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED. This allows the -functions to read and write ints to be disabled independently of -PNG_USE_READ_MACROS, which allows libpng to be built with the functions -even though the default is to use the macros - this allows applications -to choose at app buildtime whether or not to use macros (previously -impossible because the functions weren't in the default build.) - -XII. Changes to Libpng from version 1.5.x to 1.6.x - -A "simplified API" has been added (see documentation in png.h and a simple -example in contrib/examples/pngtopng.c). The new publicly visible API -includes the following: - - macros: - PNG_FORMAT_* - PNG_IMAGE_* - structures: - png_control - png_image - read functions - png_image_begin_read_from_file() - png_image_begin_read_from_stdio() - png_image_begin_read_from_memory() - png_image_finish_read() - png_image_free() - write functions - png_image_write_to_file() - png_image_write_to_memory() - png_image_write_to_stdio() - -Starting with libpng-1.6.0, you can configure libpng to prefix all exported -symbols, using the PNG_PREFIX macro. - -We no longer include string.h in png.h. The include statement has been moved -to pngpriv.h, where it is not accessible by applications. Applications that -need access to information in string.h must add an '#include <string.h>' -directive. It does not matter whether this is placed prior to or after -the '#include "png.h"' directive. - -The following API are now DEPRECATED: - png_info_init_3() - png_convert_to_rfc1123() which has been replaced - with png_convert_to_rfc1123_buffer() - png_malloc_default() - png_free_default() - png_reset_zstream() - -The following have been removed: - png_get_io_chunk_name(), which has been replaced - with png_get_io_chunk_type(). The new - function returns a 32-bit integer instead of - a string. - The png_sizeof(), png_strlen(), png_memcpy(), png_memcmp(), and - png_memset() macros are no longer used in the libpng sources and - have been removed. These had already been made invisible to applications - (i.e., defined in the private pngpriv.h header file) since libpng-1.5.0. - -The signatures of many exported functions were changed, such that - png_structp became png_structrp or png_const_structrp - png_infop became png_inforp or png_const_inforp -where "rp" indicates a "restricted pointer". - -Dropped support for 16-bit platforms. The support for FAR/far types has -been eliminated and the definition of png_alloc_size_t is now controlled -by a flag so that 'small size_t' systems can select it if necessary. - -Error detection in some chunks has improved; in particular the iCCP chunk -reader now does pretty complete validation of the basic format. Some bad -profiles that were previously accepted are now accepted with a warning or -rejected, depending upon the png_set_benign_errors() setting, in particular -the very old broken Microsoft/HP 3144-byte sRGB profile. Starting with -libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by -means of - - #if defined(PNG_SKIP_sRGB_CHECK_PROFILE) && \ - defined(PNG_SET_OPTION_SUPPORTED) - png_set_option(png_ptr, PNG_SKIP_sRGB_CHECK_PROFILE, - PNG_OPTION_ON); - #endif - -It's not a good idea to do this if you are using the "simplified API", -which needs to be able to recognize sRGB profiles conveyed via the iCCP -chunk. - -The PNG spec requirement that only grayscale profiles may appear in images -with color type 0 or 4 and that even if the image only contains gray pixels, -only RGB profiles may appear in images with color type 2, 3, or 6, is now -enforced. The sRGB chunk is allowed to appear in images with any color type -and is interpreted by libpng to convey a one-tracer-curve gray profile or a -three-tracer-curve RGB profile as appropriate. - -Libpng 1.5.x erroneously used /MD for Debug DLL builds; if you used the debug -builds in your app and you changed your app to use /MD you will need to -change it back to /MDd for libpng 1.6.x. - -Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained -an empty language field or an empty translated keyword. Both of these -are allowed by the PNG specification, so these warnings are no longer issued. - -The library now issues an error if the application attempts to set a -transform after it calls png_read_update_info() or if it attempts to call -both png_read_update_info() and png_start_read_image() or to call either -of them more than once. - -The default condition for benign_errors is now to treat benign errors as -warnings while reading and as errors while writing. - -The library now issues a warning if both background processing and RGB to -gray are used when gamma correction happens. As with previous versions of -the library the results are numerically very incorrect in this case. - -There are some minor arithmetic changes in some transforms such as -png_set_background(), that might be detected by certain regression tests. - -Unknown chunk handling has been improved internally, without any API change. -This adds more correct option control of the unknown handling, corrects -a pre-existing bug where the per-chunk 'keep' setting is ignored, and makes -it possible to skip IDAT chunks in the sequential reader. - -The machine-generated configure files are no longer included in branches -libpng16 and later of the GIT repository. They continue to be included -in the tarball releases, however. - -Libpng-1.6.0 through 1.6.2 used the CMF bytes at the beginning of the IDAT -stream to set the size of the sliding window for reading instead of using the -default 32-kbyte sliding window size. It was discovered that there are -hundreds of PNG files in the wild that have incorrect CMF bytes that caused -zlib to issue the "invalid distance too far back" error and reject the file. -Libpng-1.6.3 and later calculate their own safe CMF from the image dimensions, -provide a way to revert to the libpng-1.5.x behavior (ignoring the CMF bytes -and using a 32-kbyte sliding window), by using - - png_set_option(png_ptr, PNG_MAXIMUM_INFLATE_WINDOW, - PNG_OPTION_ON); - -and provide a tool (contrib/tools/pngfix) for rewriting a PNG file while -optimizing the CMF bytes in its IDAT chunk correctly. - -Libpng-1.6.0 and libpng-1.6.1 wrote uncompressed iTXt chunks with the wrong -length, which resulted in PNG files that cannot be read beyond the bad iTXt -chunk. This error was fixed in libpng-1.6.3, and a tool (called -contrib/tools/png-fix-itxt) has been added to the libpng distribution. - -Starting with libpng-1.6.17, the PNG_SAFE_LIMITS macro was eliminated -and safe limits are used by default (users who need larger limits -can still override them at compile time or run time, as described above). - -The new limits are - default spec limit - png_user_width_max 1,000,000 2,147,483,647 - png_user_height_max 1,000,000 2,147,483,647 - png_user_chunk_cache_max 128 unlimited - png_user_chunk_malloc_max 8,000,000 unlimited - -Starting with libpng-1.6.18, a PNG_RELEASE_BUILD macro was added, which allows -library builders to control compilation for an installed system (a release build). -It can be set for testing debug or beta builds to ensure that they will compile -when the build type is switched to RC or STABLE. In essence this overrides the -PNG_LIBPNG_BUILD_BASE_TYPE definition which is not directly user controllable. - -Starting with libpng-1.6.19, attempting to set an over-length PLTE chunk -is an error. Previously this requirement of the PNG specification was not -enforced, and the palette was always limited to 256 entries. An over-length -PLTE chunk found in an input PNG is silently truncated. - -XIII. Detecting libpng - -The png_get_io_ptr() function has been present since libpng-0.88, has never -changed, and is unaffected by conditional compilation macros. It is the -best choice for use in configure scripts for detecting the presence of any -libpng version since 0.88. In an autoconf "configure.in" you could use - - AC_CHECK_LIB(png, png_get_io_ptr, ... - -XV. Source code repository - -Since about February 2009, version 1.2.34, libpng has been under "git" source -control. The git repository was built from old libpng-x.y.z.tar.gz files -going back to version 0.70. You can access the git repository (read only) -at - - git://git.code.sf.net/p/libpng/code - -or you can browse it with a web browser by selecting the "code" button at - - https://sourceforge.net/projects/libpng - -Patches can be sent to glennrp at users.sourceforge.net or to -png-mng-implement at lists.sourceforge.net or you can upload them to -the libpng bug tracker at - - http://libpng.sourceforge.net - -We also accept patches built from the tar or zip distributions, and -simple verbal discriptions of bug fixes, reported either to the -SourceForge bug tracker, to the png-mng-implement at lists.sf.net -mailing list, or directly to glennrp. - -XV. Coding style - -Our coding style is similar to the "Allman" style -(See http://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly -braces on separate lines: - - if (condition) - { - action; - } - - else if (another condition) - { - another action; - } - -The braces can be omitted from simple one-line actions: - - if (condition) - return (0); - -We use 3-space indentation, except for continued statements which -are usually indented the same as the first line of the statement -plus four more spaces. - -For macro definitions we use 2-space indentation, always leaving the "#" -in the first column. - - #ifndef PNG_NO_FEATURE - # ifndef PNG_FEATURE_SUPPORTED - # define PNG_FEATURE_SUPPORTED - # endif - #endif - -Comments appear with the leading "/*" at the same indentation as -the statement that follows the comment: - - /* Single-line comment */ - statement; - - /* This is a multiple-line - * comment. - */ - statement; - -Very short comments can be placed after the end of the statement -to which they pertain: - - statement; /* comment */ - -We don't use C++ style ("//") comments. We have, however, -used them in the past in some now-abandoned MMX assembler -code. - -Functions and their curly braces are not indented, and -exported functions are marked with PNGAPI: - - /* This is a public function that is visible to - * application programmers. It does thus-and-so. - */ - void PNGAPI - png_exported_function(png_ptr, png_info, foo) - { - body; - } - -The return type and decorations are placed on a separate line -ahead of the function name, as illustrated above. - -The prototypes for all exported functions appear in png.h, -above the comment that says - - /* Maintainer: Put new public prototypes here ... */ - -We mark all non-exported functions with "/* PRIVATE */"": - - void /* PRIVATE */ - png_non_exported_function(png_ptr, png_info, foo) - { - body; - } - -The prototypes for non-exported functions (except for those in -pngtest) appear in pngpriv.h above the comment that says - - /* Maintainer: Put new private prototypes here ^ */ - -To avoid polluting the global namespace, the names of all exported -functions and variables begin with "png_", and all publicly visible C -preprocessor macros begin with "PNG". We request that applications that -use libpng *not* begin any of their own symbols with either of these strings. - -We put a space after the "sizeof" operator and we omit the -optional parentheses around its argument when the argument -is an expression, not a type name, and we always enclose the -sizeof operator, with its argument, in parentheses: - - (sizeof (png_uint_32)) - (sizeof array) - -Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as -though it were a function. - -Control keywords if, for, while, and switch are always followed by a space -to distinguish them from function calls, which have no trailing space. - -We put a space after each comma and after each semicolon -in "for" statements, and we put spaces before and after each -C binary operator and after "for" or "while", and before -"?". We don't put a space between a typecast and the expression -being cast, nor do we put one between a function name and the -left parenthesis that follows it: - - for (i = 2; i > 0; --i) - y[i] = a(x) + (int)b; - -We prefer #ifdef and #ifndef to #if defined() and #if !defined() -when there is only one macro being tested. We always use parentheses -with "defined". - -We express integer constants that are used as bit masks in hex format, -with an even number of lower-case hex digits, and to make them unsigned -(e.g., 0x00U, 0xffU, 0x0100U) and long if they are greater than 0x7fff -(e.g., 0xffffUL). - -We prefer to use underscores rather than camelCase in names, except -for a few type names that we inherit from zlib.h. - -We prefer "if (something != 0)" and "if (something == 0)" -over "if (something)" and if "(!something)", respectively. - -We do not use the TAB character for indentation in the C sources. - -Lines do not exceed 80 characters. - -Other rules can be inferred by inspecting the libpng source. - -XVI. Y2K Compliance in libpng - -Since the PNG Development group is an ad-hoc body, we can't make -an official declaration. - -This is your unofficial assurance that libpng from version 0.71 and -upward through 1.6.22rc01 are Y2K compliant. It is my belief that earlier -versions were also Y2K compliant. - -Libpng only has two year fields. One is a 2-byte unsigned integer -that will hold years up to 65535. The other, which is deprecated, -holds the date in text format, and will hold years up to 9999. - -The integer is - "png_uint_16 year" in png_time_struct. - -The string is - "char time_buffer[29]" in png_struct. This is no longer used -in libpng-1.6.x and will be removed from libpng-1.7.0. - -There are seven time-related functions: - - png_convert_to_rfc_1123_buffer() in png.c - (formerly png_convert_to_rfc_1152() in error, and - also formerly png_convert_to_rfc_1123()) - png_convert_from_struct_tm() in pngwrite.c, called - in pngwrite.c - png_convert_from_time_t() in pngwrite.c - png_get_tIME() in pngget.c - png_handle_tIME() in pngrutil.c, called in pngread.c - png_set_tIME() in pngset.c - png_write_tIME() in pngwutil.c, called in pngwrite.c - -All appear to handle dates properly in a Y2K environment. The -png_convert_from_time_t() function calls gmtime() to convert from system -clock time, which returns (year - 1900), which we properly convert to -the full 4-digit year. There is a possibility that applications using -libpng are not passing 4-digit years into the png_convert_to_rfc_1123() -function, or that they are incorrectly passing only a 2-digit year -instead of "year - 1900" into the png_convert_from_struct_tm() function, -but this is not under our control. The libpng documentation has always -stated that it works with 4-digit years, and the APIs have been -documented as such. - -The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned -integer to hold the year, and can hold years as large as 65535. - -zlib, upon which libpng depends, is also Y2K compliant. It contains -no date-related code. - - - Glenn Randers-Pehrson - libpng maintainer - PNG Development Group diff --git a/third_party/libpng/png.c b/third_party/libpng/png.c deleted file mode 100644 index d03cbdfe44..0000000000 --- a/third_party/libpng/png.c +++ /dev/null @@ -1,4499 +0,0 @@ - -/* png.c - location for general purpose libpng functions - * - * Last changed in libpng 1.6.19 [November 12, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "pngpriv.h" - -/* Generate a compiler error if there is an old png.h in the search path. */ -typedef png_libpng_version_1_6_22rc01 Your_png_h_is_not_version_1_6_22rc01; - -/* Tells libpng that we have already handled the first "num_bytes" bytes - * of the PNG file signature. If the PNG data is embedded into another - * stream we can set num_bytes = 8 so that libpng will not attempt to read - * or write any of the magic bytes before it starts on the IHDR. - */ - -#ifdef PNG_READ_SUPPORTED -void PNGAPI -png_set_sig_bytes(png_structrp png_ptr, int num_bytes) -{ - unsigned int nb = (unsigned int)num_bytes; - - png_debug(1, "in png_set_sig_bytes"); - - if (png_ptr == NULL) - return; - - if (num_bytes < 0) - nb = 0; - - if (nb > 8) - png_error(png_ptr, "Too many bytes for PNG signature"); - - png_ptr->sig_bytes = (png_byte)nb; -} - -/* Checks whether the supplied bytes match the PNG signature. We allow - * checking less than the full 8-byte signature so that those apps that - * already read the first few bytes of a file to determine the file type - * can simply check the remaining bytes for extra assurance. Returns - * an integer less than, equal to, or greater than zero if sig is found, - * respectively, to be less than, to match, or be greater than the correct - * PNG signature (this is the same behavior as strcmp, memcmp, etc). - */ -int PNGAPI -png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check) -{ - png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; - - if (num_to_check > 8) - num_to_check = 8; - - else if (num_to_check < 1) - return (-1); - - if (start > 7) - return (-1); - - if (start + num_to_check > 8) - num_to_check = 8 - start; - - return ((int)(memcmp(&sig[start], &png_signature[start], num_to_check))); -} - -#endif /* READ */ - -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) -/* Function to allocate memory for zlib */ -PNG_FUNCTION(voidpf /* PRIVATE */, -png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED) -{ - png_alloc_size_t num_bytes = size; - - if (png_ptr == NULL) - return NULL; - - if (items >= (~(png_alloc_size_t)0)/size) - { - png_warning (png_voidcast(png_structrp, png_ptr), - "Potential overflow in png_zalloc()"); - return NULL; - } - - num_bytes *= items; - return png_malloc_warn(png_voidcast(png_structrp, png_ptr), num_bytes); -} - -/* Function to free memory for zlib */ -void /* PRIVATE */ -png_zfree(voidpf png_ptr, voidpf ptr) -{ - png_free(png_voidcast(png_const_structrp,png_ptr), ptr); -} - -/* Reset the CRC variable to 32 bits of 1's. Care must be taken - * in case CRC is > 32 bits to leave the top bits 0. - */ -void /* PRIVATE */ -png_reset_crc(png_structrp png_ptr) -{ - /* The cast is safe because the crc is a 32-bit value. */ - png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0); -} - -/* Calculate the CRC over a section of data. We can only pass as - * much data to this routine as the largest single buffer size. We - * also check that this data will actually be used before going to the - * trouble of calculating it. - */ -void /* PRIVATE */ -png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, png_size_t length) -{ - int need_crc = 1; - - if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0) - { - if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == - (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) - need_crc = 0; - } - - else /* critical */ - { - if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0) - need_crc = 0; - } - - /* 'uLong' is defined in zlib.h as unsigned long; this means that on some - * systems it is a 64-bit value. crc32, however, returns 32 bits so the - * following cast is safe. 'uInt' may be no more than 16 bits, so it is - * necessary to perform a loop here. - */ - if (need_crc != 0 && length > 0) - { - uLong crc = png_ptr->crc; /* Should never issue a warning */ - - do - { - uInt safe_length = (uInt)length; -#ifndef __COVERITY__ - if (safe_length == 0) - safe_length = (uInt)-1; /* evil, but safe */ -#endif - - crc = crc32(crc, ptr, safe_length); - - /* The following should never issue compiler warnings; if they do the - * target system has characteristics that will probably violate other - * assumptions within the libpng code. - */ - ptr += safe_length; - length -= safe_length; - } - while (length > 0); - - /* And the following is always safe because the crc is only 32 bits. */ - png_ptr->crc = (png_uint_32)crc; - } -} - -/* Check a user supplied version number, called from both read and write - * functions that create a png_struct. - */ -int -png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver) -{ - /* Libpng versions 1.0.0 and later are binary compatible if the version - * string matches through the second '.'; we must recompile any - * applications that use any older library version. - */ - - if (user_png_ver != NULL) - { - int i = -1; - int found_dots = 0; - - do - { - i++; - if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i]) - png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; - if (user_png_ver[i] == '.') - found_dots++; - } while (found_dots < 2 && user_png_ver[i] != 0 && - PNG_LIBPNG_VER_STRING[i] != 0); - } - - else - png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; - - if ((png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) != 0) - { -#ifdef PNG_WARNINGS_SUPPORTED - size_t pos = 0; - char m[128]; - - pos = png_safecat(m, (sizeof m), pos, - "Application built with libpng-"); - pos = png_safecat(m, (sizeof m), pos, user_png_ver); - pos = png_safecat(m, (sizeof m), pos, " but running with "); - pos = png_safecat(m, (sizeof m), pos, PNG_LIBPNG_VER_STRING); - PNG_UNUSED(pos) - - png_warning(png_ptr, m); -#endif - -#ifdef PNG_ERROR_NUMBERS_SUPPORTED - png_ptr->flags = 0; -#endif - - return 0; - } - - /* Success return. */ - return 1; -} - -/* Generic function to create a png_struct for either read or write - this - * contains the common initialization. - */ -PNG_FUNCTION(png_structp /* PRIVATE */, -png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr, - png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, - png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) -{ - png_struct create_struct; -# ifdef PNG_SETJMP_SUPPORTED - jmp_buf create_jmp_buf; -# endif - - /* This temporary stack-allocated structure is used to provide a place to - * build enough context to allow the user provided memory allocator (if any) - * to be called. - */ - memset(&create_struct, 0, (sizeof create_struct)); - - /* Added at libpng-1.2.6 */ -# ifdef PNG_USER_LIMITS_SUPPORTED - create_struct.user_width_max = PNG_USER_WIDTH_MAX; - create_struct.user_height_max = PNG_USER_HEIGHT_MAX; - -# ifdef PNG_USER_CHUNK_CACHE_MAX - /* Added at libpng-1.2.43 and 1.4.0 */ - create_struct.user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX; -# endif - -# ifdef PNG_USER_CHUNK_MALLOC_MAX - /* Added at libpng-1.2.43 and 1.4.1, required only for read but exists - * in png_struct regardless. - */ - create_struct.user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX; -# endif -# endif - - /* The following two API calls simply set fields in png_struct, so it is safe - * to do them now even though error handling is not yet set up. - */ -# ifdef PNG_USER_MEM_SUPPORTED - png_set_mem_fn(&create_struct, mem_ptr, malloc_fn, free_fn); -# else - PNG_UNUSED(mem_ptr) - PNG_UNUSED(malloc_fn) - PNG_UNUSED(free_fn) -# endif - - /* (*error_fn) can return control to the caller after the error_ptr is set, - * this will result in a memory leak unless the error_fn does something - * extremely sophisticated. The design lacks merit but is implicit in the - * API. - */ - png_set_error_fn(&create_struct, error_ptr, error_fn, warn_fn); - -# ifdef PNG_SETJMP_SUPPORTED - if (!setjmp(create_jmp_buf)) -# endif - { -# ifdef PNG_SETJMP_SUPPORTED - /* Temporarily fake out the longjmp information until we have - * successfully completed this function. This only works if we have - * setjmp() support compiled in, but it is safe - this stuff should - * never happen. - */ - create_struct.jmp_buf_ptr = &create_jmp_buf; - create_struct.jmp_buf_size = 0; /*stack allocation*/ - create_struct.longjmp_fn = longjmp; -# endif - /* Call the general version checker (shared with read and write code): - */ - if (png_user_version_check(&create_struct, user_png_ver) != 0) - { - png_structrp png_ptr = png_voidcast(png_structrp, - png_malloc_warn(&create_struct, (sizeof *png_ptr))); - - if (png_ptr != NULL) - { - /* png_ptr->zstream holds a back-pointer to the png_struct, so - * this can only be done now: - */ - create_struct.zstream.zalloc = png_zalloc; - create_struct.zstream.zfree = png_zfree; - create_struct.zstream.opaque = png_ptr; - -# ifdef PNG_SETJMP_SUPPORTED - /* Eliminate the local error handling: */ - create_struct.jmp_buf_ptr = NULL; - create_struct.jmp_buf_size = 0; - create_struct.longjmp_fn = 0; -# endif - - *png_ptr = create_struct; - - /* This is the successful return point */ - return png_ptr; - } - } - } - - /* A longjmp because of a bug in the application storage allocator or a - * simple failure to allocate the png_struct. - */ - return NULL; -} - -/* Allocate the memory for an info_struct for the application. */ -PNG_FUNCTION(png_infop,PNGAPI -png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED) -{ - png_inforp info_ptr; - - png_debug(1, "in png_create_info_struct"); - - if (png_ptr == NULL) - return NULL; - - /* Use the internal API that does not (or at least should not) error out, so - * that this call always returns ok. The application typically sets up the - * error handling *after* creating the info_struct because this is the way it - * has always been done in 'example.c'. - */ - info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr, - (sizeof *info_ptr))); - - if (info_ptr != NULL) - memset(info_ptr, 0, (sizeof *info_ptr)); - - return info_ptr; -} - -/* This function frees the memory associated with a single info struct. - * Normally, one would use either png_destroy_read_struct() or - * png_destroy_write_struct() to free an info struct, but this may be - * useful for some applications. From libpng 1.6.0 this function is also used - * internally to implement the png_info release part of the 'struct' destroy - * APIs. This ensures that all possible approaches free the same data (all of - * it). - */ -void PNGAPI -png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr) -{ - png_inforp info_ptr = NULL; - - png_debug(1, "in png_destroy_info_struct"); - - if (png_ptr == NULL) - return; - - if (info_ptr_ptr != NULL) - info_ptr = *info_ptr_ptr; - - if (info_ptr != NULL) - { - /* Do this first in case of an error below; if the app implements its own - * memory management this can lead to png_free calling png_error, which - * will abort this routine and return control to the app error handler. - * An infinite loop may result if it then tries to free the same info - * ptr. - */ - *info_ptr_ptr = NULL; - - png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1); - memset(info_ptr, 0, (sizeof *info_ptr)); - png_free(png_ptr, info_ptr); - } -} - -/* Initialize the info structure. This is now an internal function (0.89) - * and applications using it are urged to use png_create_info_struct() - * instead. Use deprecated in 1.6.0, internal use removed (used internally it - * is just a memset). - * - * NOTE: it is almost inconceivable that this API is used because it bypasses - * the user-memory mechanism and the user error handling/warning mechanisms in - * those cases where it does anything other than a memset. - */ -PNG_FUNCTION(void,PNGAPI -png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size), - PNG_DEPRECATED) -{ - png_inforp info_ptr = *ptr_ptr; - - png_debug(1, "in png_info_init_3"); - - if (info_ptr == NULL) - return; - - if ((sizeof (png_info)) > png_info_struct_size) - { - *ptr_ptr = NULL; - /* The following line is why this API should not be used: */ - free(info_ptr); - info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL, - (sizeof *info_ptr))); - if (info_ptr == NULL) - return; - *ptr_ptr = info_ptr; - } - - /* Set everything to 0 */ - memset(info_ptr, 0, (sizeof *info_ptr)); -} - -/* The following API is not called internally */ -void PNGAPI -png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr, - int freer, png_uint_32 mask) -{ - png_debug(1, "in png_data_freer"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - if (freer == PNG_DESTROY_WILL_FREE_DATA) - info_ptr->free_me |= mask; - - else if (freer == PNG_USER_WILL_FREE_DATA) - info_ptr->free_me &= ~mask; - - else - png_error(png_ptr, "Unknown freer parameter in png_data_freer"); -} - -void PNGAPI -png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, - int num) -{ - png_debug(1, "in png_free_data"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - -#ifdef PNG_TEXT_SUPPORTED - /* Free text item num or (if num == -1) all text items */ - if (info_ptr->text != 0 && - ((mask & PNG_FREE_TEXT) & info_ptr->free_me) != 0) - { - if (num != -1) - { - png_free(png_ptr, info_ptr->text[num].key); - info_ptr->text[num].key = NULL; - } - - else - { - int i; - - for (i = 0; i < info_ptr->num_text; i++) - png_free(png_ptr, info_ptr->text[i].key); - - png_free(png_ptr, info_ptr->text); - info_ptr->text = NULL; - info_ptr->num_text = 0; - } - } -#endif - -#ifdef PNG_tRNS_SUPPORTED - /* Free any tRNS entry */ - if (((mask & PNG_FREE_TRNS) & info_ptr->free_me) != 0) - { - info_ptr->valid &= ~PNG_INFO_tRNS; - png_free(png_ptr, info_ptr->trans_alpha); - info_ptr->trans_alpha = NULL; - info_ptr->num_trans = 0; - } -#endif - -#ifdef PNG_sCAL_SUPPORTED - /* Free any sCAL entry */ - if (((mask & PNG_FREE_SCAL) & info_ptr->free_me) != 0) - { - png_free(png_ptr, info_ptr->scal_s_width); - png_free(png_ptr, info_ptr->scal_s_height); - info_ptr->scal_s_width = NULL; - info_ptr->scal_s_height = NULL; - info_ptr->valid &= ~PNG_INFO_sCAL; - } -#endif - -#ifdef PNG_pCAL_SUPPORTED - /* Free any pCAL entry */ - if (((mask & PNG_FREE_PCAL) & info_ptr->free_me) != 0) - { - png_free(png_ptr, info_ptr->pcal_purpose); - png_free(png_ptr, info_ptr->pcal_units); - info_ptr->pcal_purpose = NULL; - info_ptr->pcal_units = NULL; - - if (info_ptr->pcal_params != NULL) - { - int i; - - for (i = 0; i < info_ptr->pcal_nparams; i++) - png_free(png_ptr, info_ptr->pcal_params[i]); - - png_free(png_ptr, info_ptr->pcal_params); - info_ptr->pcal_params = NULL; - } - info_ptr->valid &= ~PNG_INFO_pCAL; - } -#endif - -#ifdef PNG_iCCP_SUPPORTED - /* Free any profile entry */ - if (((mask & PNG_FREE_ICCP) & info_ptr->free_me) != 0) - { - png_free(png_ptr, info_ptr->iccp_name); - png_free(png_ptr, info_ptr->iccp_profile); - info_ptr->iccp_name = NULL; - info_ptr->iccp_profile = NULL; - info_ptr->valid &= ~PNG_INFO_iCCP; - } -#endif - -#ifdef PNG_sPLT_SUPPORTED - /* Free a given sPLT entry, or (if num == -1) all sPLT entries */ - if (info_ptr->splt_palettes != 0 && - ((mask & PNG_FREE_SPLT) & info_ptr->free_me) != 0) - { - if (num != -1) - { - png_free(png_ptr, info_ptr->splt_palettes[num].name); - png_free(png_ptr, info_ptr->splt_palettes[num].entries); - info_ptr->splt_palettes[num].name = NULL; - info_ptr->splt_palettes[num].entries = NULL; - } - - else - { - int i; - - for (i = 0; i < info_ptr->splt_palettes_num; i++) - { - png_free(png_ptr, info_ptr->splt_palettes[i].name); - png_free(png_ptr, info_ptr->splt_palettes[i].entries); - } - - png_free(png_ptr, info_ptr->splt_palettes); - info_ptr->splt_palettes = NULL; - info_ptr->splt_palettes_num = 0; - info_ptr->valid &= ~PNG_INFO_sPLT; - } - } -#endif - -#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED - if (info_ptr->unknown_chunks != 0 && - ((mask & PNG_FREE_UNKN) & info_ptr->free_me) != 0) - { - if (num != -1) - { - png_free(png_ptr, info_ptr->unknown_chunks[num].data); - info_ptr->unknown_chunks[num].data = NULL; - } - - else - { - int i; - - for (i = 0; i < info_ptr->unknown_chunks_num; i++) - png_free(png_ptr, info_ptr->unknown_chunks[i].data); - - png_free(png_ptr, info_ptr->unknown_chunks); - info_ptr->unknown_chunks = NULL; - info_ptr->unknown_chunks_num = 0; - } - } -#endif - -#ifdef PNG_hIST_SUPPORTED - /* Free any hIST entry */ - if (((mask & PNG_FREE_HIST) & info_ptr->free_me) != 0) - { - png_free(png_ptr, info_ptr->hist); - info_ptr->hist = NULL; - info_ptr->valid &= ~PNG_INFO_hIST; - } -#endif - - /* Free any PLTE entry that was internally allocated */ - if (((mask & PNG_FREE_PLTE) & info_ptr->free_me) != 0) - { - png_free(png_ptr, info_ptr->palette); - info_ptr->palette = NULL; - info_ptr->valid &= ~PNG_INFO_PLTE; - info_ptr->num_palette = 0; - } - -#ifdef PNG_INFO_IMAGE_SUPPORTED - /* Free any image bits attached to the info structure */ - if (((mask & PNG_FREE_ROWS) & info_ptr->free_me) != 0) - { - if (info_ptr->row_pointers != 0) - { - png_uint_32 row; - for (row = 0; row < info_ptr->height; row++) - png_free(png_ptr, info_ptr->row_pointers[row]); - - png_free(png_ptr, info_ptr->row_pointers); - info_ptr->row_pointers = NULL; - } - info_ptr->valid &= ~PNG_INFO_IDAT; - } -#endif - - if (num != -1) - mask &= ~PNG_FREE_MUL; - - info_ptr->free_me &= ~mask; -} -#endif /* READ || WRITE */ - -/* This function returns a pointer to the io_ptr associated with the user - * functions. The application should free any memory associated with this - * pointer before png_write_destroy() or png_read_destroy() are called. - */ -png_voidp PNGAPI -png_get_io_ptr(png_const_structrp png_ptr) -{ - if (png_ptr == NULL) - return (NULL); - - return (png_ptr->io_ptr); -} - -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) -# ifdef PNG_STDIO_SUPPORTED -/* Initialize the default input/output functions for the PNG file. If you - * use your own read or write routines, you can call either png_set_read_fn() - * or png_set_write_fn() instead of png_init_io(). If you have defined - * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a - * function of your own because "FILE *" isn't necessarily available. - */ -void PNGAPI -png_init_io(png_structrp png_ptr, png_FILE_p fp) -{ - png_debug(1, "in png_init_io"); - - if (png_ptr == NULL) - return; - - png_ptr->io_ptr = (png_voidp)fp; -} -# endif - -# ifdef PNG_SAVE_INT_32_SUPPORTED -/* PNG signed integers are saved in 32-bit 2's complement format. ANSI C-90 - * defines a cast of a signed integer to an unsigned integer either to preserve - * the value, if it is positive, or to calculate: - * - * (UNSIGNED_MAX+1) + integer - * - * Where UNSIGNED_MAX is the appropriate maximum unsigned value, so when the - * negative integral value is added the result will be an unsigned value - * correspnding to the 2's complement representation. - */ -void PNGAPI -png_save_int_32(png_bytep buf, png_int_32 i) -{ - png_save_uint_32(buf, i); -} -# endif - -# ifdef PNG_TIME_RFC1123_SUPPORTED -/* Convert the supplied time into an RFC 1123 string suitable for use in - * a "Creation Time" or other text-based time string. - */ -int PNGAPI -png_convert_to_rfc1123_buffer(char out[29], png_const_timep ptime) -{ - static PNG_CONST char short_months[12][4] = - {"Jan", "Feb", "Mar", "Apr", "May", "Jun", - "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; - - if (out == NULL) - return 0; - - if (ptime->year > 9999 /* RFC1123 limitation */ || - ptime->month == 0 || ptime->month > 12 || - ptime->day == 0 || ptime->day > 31 || - ptime->hour > 23 || ptime->minute > 59 || - ptime->second > 60) - return 0; - - { - size_t pos = 0; - char number_buf[5]; /* enough for a four-digit year */ - -# define APPEND_STRING(string) pos = png_safecat(out, 29, pos, (string)) -# define APPEND_NUMBER(format, value)\ - APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value))) -# define APPEND(ch) if (pos < 28) out[pos++] = (ch) - - APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day); - APPEND(' '); - APPEND_STRING(short_months[(ptime->month - 1)]); - APPEND(' '); - APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year); - APPEND(' '); - APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour); - APPEND(':'); - APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute); - APPEND(':'); - APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second); - APPEND_STRING(" +0000"); /* This reliably terminates the buffer */ - PNG_UNUSED (pos) - -# undef APPEND -# undef APPEND_NUMBER -# undef APPEND_STRING - } - - return 1; -} - -# if PNG_LIBPNG_VER < 10700 -/* To do: remove the following from libpng-1.7 */ -/* Original API that uses a private buffer in png_struct. - * Deprecated because it causes png_struct to carry a spurious temporary - * buffer (png_struct::time_buffer), better to have the caller pass this in. - */ -png_const_charp PNGAPI -png_convert_to_rfc1123(png_structrp png_ptr, png_const_timep ptime) -{ - if (png_ptr != NULL) - { - /* The only failure above if png_ptr != NULL is from an invalid ptime */ - if (png_convert_to_rfc1123_buffer(png_ptr->time_buffer, ptime) == 0) - png_warning(png_ptr, "Ignoring invalid time value"); - - else - return png_ptr->time_buffer; - } - - return NULL; -} -# endif /* LIBPNG_VER < 10700 */ -# endif /* TIME_RFC1123 */ - -#endif /* READ || WRITE */ - -png_const_charp PNGAPI -png_get_copyright(png_const_structrp png_ptr) -{ - PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ -#ifdef PNG_STRING_COPYRIGHT - return PNG_STRING_COPYRIGHT -#else -# ifdef __STDC__ - return PNG_STRING_NEWLINE \ - "libpng version 1.6.22rc01 - May 14, 2016" PNG_STRING_NEWLINE \ - "Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson" \ - PNG_STRING_NEWLINE \ - "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \ - "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \ - PNG_STRING_NEWLINE; -# else - return "libpng version 1.6.22rc01 - May 14, 2016\ - Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson\ - Copyright (c) 1996-1997 Andreas Dilger\ - Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc."; -# endif -#endif -} - -/* The following return the library version as a short string in the - * format 1.0.0 through 99.99.99zz. To get the version of *.h files - * used with your application, print out PNG_LIBPNG_VER_STRING, which - * is defined in png.h. - * Note: now there is no difference between png_get_libpng_ver() and - * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard, - * it is guaranteed that png.c uses the correct version of png.h. - */ -png_const_charp PNGAPI -png_get_libpng_ver(png_const_structrp png_ptr) -{ - /* Version of *.c files used when building libpng */ - return png_get_header_ver(png_ptr); -} - -png_const_charp PNGAPI -png_get_header_ver(png_const_structrp png_ptr) -{ - /* Version of *.h files used when building libpng */ - PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ - return PNG_LIBPNG_VER_STRING; -} - -png_const_charp PNGAPI -png_get_header_version(png_const_structrp png_ptr) -{ - /* Returns longer string containing both version and date */ - PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ -#ifdef __STDC__ - return PNG_HEADER_VERSION_STRING -# ifndef PNG_READ_SUPPORTED - " (NO READ SUPPORT)" -# endif - PNG_STRING_NEWLINE; -#else - return PNG_HEADER_VERSION_STRING; -#endif -} - -#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED -/* NOTE: this routine is not used internally! */ -/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth - * large of png_color. This lets grayscale images be treated as - * paletted. Most useful for gamma correction and simplification - * of code. This API is not used internally. - */ -void PNGAPI -png_build_grayscale_palette(int bit_depth, png_colorp palette) -{ - int num_palette; - int color_inc; - int i; - int v; - - png_debug(1, "in png_do_build_grayscale_palette"); - - if (palette == NULL) - return; - - switch (bit_depth) - { - case 1: - num_palette = 2; - color_inc = 0xff; - break; - - case 2: - num_palette = 4; - color_inc = 0x55; - break; - - case 4: - num_palette = 16; - color_inc = 0x11; - break; - - case 8: - num_palette = 256; - color_inc = 1; - break; - - default: - num_palette = 0; - color_inc = 0; - break; - } - - for (i = 0, v = 0; i < num_palette; i++, v += color_inc) - { - palette[i].red = (png_byte)(v & 0xff); - palette[i].green = (png_byte)(v & 0xff); - palette[i].blue = (png_byte)(v & 0xff); - } -} -#endif - -#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED -int PNGAPI -png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name) -{ - /* Check chunk_name and return "keep" value if it's on the list, else 0 */ - png_const_bytep p, p_end; - - if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list == 0) - return PNG_HANDLE_CHUNK_AS_DEFAULT; - - p_end = png_ptr->chunk_list; - p = p_end + png_ptr->num_chunk_list*5; /* beyond end */ - - /* The code is the fifth byte after each four byte string. Historically this - * code was always searched from the end of the list, this is no longer - * necessary because the 'set' routine handles duplicate entries correcty. - */ - do /* num_chunk_list > 0, so at least one */ - { - p -= 5; - - if (memcmp(chunk_name, p, 4) == 0) - return p[4]; - } - while (p > p_end); - - /* This means that known chunks should be processed and unknown chunks should - * be handled according to the value of png_ptr->unknown_default; this can be - * confusing because, as a result, there are two levels of defaulting for - * unknown chunks. - */ - return PNG_HANDLE_CHUNK_AS_DEFAULT; -} - -#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\ - defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) -int /* PRIVATE */ -png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name) -{ - png_byte chunk_string[5]; - - PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name); - return png_handle_as_unknown(png_ptr, chunk_string); -} -#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */ -#endif /* SET_UNKNOWN_CHUNKS */ - -#ifdef PNG_READ_SUPPORTED -/* This function, added to libpng-1.0.6g, is untested. */ -int PNGAPI -png_reset_zstream(png_structrp png_ptr) -{ - if (png_ptr == NULL) - return Z_STREAM_ERROR; - - /* WARNING: this resets the window bits to the maximum! */ - return (inflateReset(&png_ptr->zstream)); -} -#endif /* READ */ - -/* This function was added to libpng-1.0.7 */ -png_uint_32 PNGAPI -png_access_version_number(void) -{ - /* Version of *.c files used when building libpng */ - return((png_uint_32)PNG_LIBPNG_VER); -} - -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) -/* Ensure that png_ptr->zstream.msg holds some appropriate error message string. - * If it doesn't 'ret' is used to set it to something appropriate, even in cases - * like Z_OK or Z_STREAM_END where the error code is apparently a success code. - */ -void /* PRIVATE */ -png_zstream_error(png_structrp png_ptr, int ret) -{ - /* Translate 'ret' into an appropriate error string, priority is given to the - * one in zstream if set. This always returns a string, even in cases like - * Z_OK or Z_STREAM_END where the error code is a success code. - */ - if (png_ptr->zstream.msg == NULL) switch (ret) - { - default: - case Z_OK: - png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return code"); - break; - - case Z_STREAM_END: - /* Normal exit */ - png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected end of LZ stream"); - break; - - case Z_NEED_DICT: - /* This means the deflate stream did not have a dictionary; this - * indicates a bogus PNG. - */ - png_ptr->zstream.msg = PNGZ_MSG_CAST("missing LZ dictionary"); - break; - - case Z_ERRNO: - /* gz APIs only: should not happen */ - png_ptr->zstream.msg = PNGZ_MSG_CAST("zlib IO error"); - break; - - case Z_STREAM_ERROR: - /* internal libpng error */ - png_ptr->zstream.msg = PNGZ_MSG_CAST("bad parameters to zlib"); - break; - - case Z_DATA_ERROR: - png_ptr->zstream.msg = PNGZ_MSG_CAST("damaged LZ stream"); - break; - - case Z_MEM_ERROR: - png_ptr->zstream.msg = PNGZ_MSG_CAST("insufficient memory"); - break; - - case Z_BUF_ERROR: - /* End of input or output; not a problem if the caller is doing - * incremental read or write. - */ - png_ptr->zstream.msg = PNGZ_MSG_CAST("truncated"); - break; - - case Z_VERSION_ERROR: - png_ptr->zstream.msg = PNGZ_MSG_CAST("unsupported zlib version"); - break; - - case PNG_UNEXPECTED_ZLIB_RETURN: - /* Compile errors here mean that zlib now uses the value co-opted in - * pngpriv.h for PNG_UNEXPECTED_ZLIB_RETURN; update the switch above - * and change pngpriv.h. Note that this message is "... return", - * whereas the default/Z_OK one is "... return code". - */ - png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return"); - break; - } -} - -/* png_convert_size: a PNGAPI but no longer in png.h, so deleted - * at libpng 1.5.5! - */ - -/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */ -#ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */ -static int -png_colorspace_check_gamma(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_fixed_point gAMA, int from) - /* This is called to check a new gamma value against an existing one. The - * routine returns false if the new gamma value should not be written. - * - * 'from' says where the new gamma value comes from: - * - * 0: the new gamma value is the libpng estimate for an ICC profile - * 1: the new gamma value comes from a gAMA chunk - * 2: the new gamma value comes from an sRGB chunk - */ -{ - png_fixed_point gtest; - - if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && - (png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) == 0 || - png_gamma_significant(gtest) != 0)) - { - /* Either this is an sRGB image, in which case the calculated gamma - * approximation should match, or this is an image with a profile and the - * value libpng calculates for the gamma of the profile does not match the - * value recorded in the file. The former, sRGB, case is an error, the - * latter is just a warning. - */ - if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2) - { - png_chunk_report(png_ptr, "gamma value does not match sRGB", - PNG_CHUNK_ERROR); - /* Do not overwrite an sRGB value */ - return from == 2; - } - - else /* sRGB tag not involved */ - { - png_chunk_report(png_ptr, "gamma value does not match libpng estimate", - PNG_CHUNK_WARNING); - return from == 1; - } - } - - return 1; -} - -void /* PRIVATE */ -png_colorspace_set_gamma(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_fixed_point gAMA) -{ - /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't - * occur. Since the fixed point representation is asymetrical it is - * possible for 1/gamma to overflow the limit of 21474 and this means the - * gamma value must be at least 5/100000 and hence at most 20000.0. For - * safety the limits here are a little narrower. The values are 0.00016 to - * 6250.0, which are truly ridiculous gamma values (and will produce - * displays that are all black or all white.) - * - * In 1.6.0 this test replaces the ones in pngrutil.c, in the gAMA chunk - * handling code, which only required the value to be >0. - */ - png_const_charp errmsg; - - if (gAMA < 16 || gAMA > 625000000) - errmsg = "gamma value out of range"; - -# ifdef PNG_READ_gAMA_SUPPORTED - /* Allow the application to set the gamma value more than once */ - else if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && - (colorspace->flags & PNG_COLORSPACE_FROM_gAMA) != 0) - errmsg = "duplicate"; -# endif - - /* Do nothing if the colorspace is already invalid */ - else if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) - return; - - else - { - if (png_colorspace_check_gamma(png_ptr, colorspace, gAMA, - 1/*from gAMA*/) != 0) - { - /* Store this gamma value. */ - colorspace->gamma = gAMA; - colorspace->flags |= - (PNG_COLORSPACE_HAVE_GAMMA | PNG_COLORSPACE_FROM_gAMA); - } - - /* At present if the check_gamma test fails the gamma of the colorspace is - * not updated however the colorspace is not invalidated. This - * corresponds to the case where the existing gamma comes from an sRGB - * chunk or profile. An error message has already been output. - */ - return; - } - - /* Error exit - errmsg has been set. */ - colorspace->flags |= PNG_COLORSPACE_INVALID; - png_chunk_report(png_ptr, errmsg, PNG_CHUNK_WRITE_ERROR); -} - -void /* PRIVATE */ -png_colorspace_sync_info(png_const_structrp png_ptr, png_inforp info_ptr) -{ - if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) - { - /* Everything is invalid */ - info_ptr->valid &= ~(PNG_INFO_gAMA|PNG_INFO_cHRM|PNG_INFO_sRGB| - PNG_INFO_iCCP); - -# ifdef PNG_COLORSPACE_SUPPORTED - /* Clean up the iCCP profile now if it won't be used. */ - png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, -1/*not used*/); -# else - PNG_UNUSED(png_ptr) -# endif - } - - else - { -# ifdef PNG_COLORSPACE_SUPPORTED - /* Leave the INFO_iCCP flag set if the pngset.c code has already set - * it; this allows a PNG to contain a profile which matches sRGB and - * yet still have that profile retrievable by the application. - */ - if ((info_ptr->colorspace.flags & PNG_COLORSPACE_MATCHES_sRGB) != 0) - info_ptr->valid |= PNG_INFO_sRGB; - - else - info_ptr->valid &= ~PNG_INFO_sRGB; - - if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) - info_ptr->valid |= PNG_INFO_cHRM; - - else - info_ptr->valid &= ~PNG_INFO_cHRM; -# endif - - if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0) - info_ptr->valid |= PNG_INFO_gAMA; - - else - info_ptr->valid &= ~PNG_INFO_gAMA; - } -} - -#ifdef PNG_READ_SUPPORTED -void /* PRIVATE */ -png_colorspace_sync(png_const_structrp png_ptr, png_inforp info_ptr) -{ - if (info_ptr == NULL) /* reduce code size; check here not in the caller */ - return; - - info_ptr->colorspace = png_ptr->colorspace; - png_colorspace_sync_info(png_ptr, info_ptr); -} -#endif -#endif /* GAMMA */ - -#ifdef PNG_COLORSPACE_SUPPORTED -/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for - * cHRM, as opposed to using chromaticities. These internal APIs return - * non-zero on a parameter error. The X, Y and Z values are required to be - * positive and less than 1.0. - */ -static int -png_xy_from_XYZ(png_xy *xy, const png_XYZ *XYZ) -{ - png_int_32 d, dwhite, whiteX, whiteY; - - d = XYZ->red_X + XYZ->red_Y + XYZ->red_Z; - if (png_muldiv(&xy->redx, XYZ->red_X, PNG_FP_1, d) == 0) - return 1; - if (png_muldiv(&xy->redy, XYZ->red_Y, PNG_FP_1, d) == 0) - return 1; - dwhite = d; - whiteX = XYZ->red_X; - whiteY = XYZ->red_Y; - - d = XYZ->green_X + XYZ->green_Y + XYZ->green_Z; - if (png_muldiv(&xy->greenx, XYZ->green_X, PNG_FP_1, d) == 0) - return 1; - if (png_muldiv(&xy->greeny, XYZ->green_Y, PNG_FP_1, d) == 0) - return 1; - dwhite += d; - whiteX += XYZ->green_X; - whiteY += XYZ->green_Y; - - d = XYZ->blue_X + XYZ->blue_Y + XYZ->blue_Z; - if (png_muldiv(&xy->bluex, XYZ->blue_X, PNG_FP_1, d) == 0) - return 1; - if (png_muldiv(&xy->bluey, XYZ->blue_Y, PNG_FP_1, d) == 0) - return 1; - dwhite += d; - whiteX += XYZ->blue_X; - whiteY += XYZ->blue_Y; - - /* The reference white is simply the sum of the end-point (X,Y,Z) vectors, - * thus: - */ - if (png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite) == 0) - return 1; - if (png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite) == 0) - return 1; - - return 0; -} - -static int -png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy) -{ - png_fixed_point red_inverse, green_inverse, blue_scale; - png_fixed_point left, right, denominator; - - /* Check xy and, implicitly, z. Note that wide gamut color spaces typically - * have end points with 0 tristimulus values (these are impossible end - * points, but they are used to cover the possible colors). We check - * xy->whitey against 5, not 0, to avoid a possible integer overflow. - */ - if (xy->redx < 0 || xy->redx > PNG_FP_1) return 1; - if (xy->redy < 0 || xy->redy > PNG_FP_1-xy->redx) return 1; - if (xy->greenx < 0 || xy->greenx > PNG_FP_1) return 1; - if (xy->greeny < 0 || xy->greeny > PNG_FP_1-xy->greenx) return 1; - if (xy->bluex < 0 || xy->bluex > PNG_FP_1) return 1; - if (xy->bluey < 0 || xy->bluey > PNG_FP_1-xy->bluex) return 1; - if (xy->whitex < 0 || xy->whitex > PNG_FP_1) return 1; - if (xy->whitey < 5 || xy->whitey > PNG_FP_1-xy->whitex) return 1; - - /* The reverse calculation is more difficult because the original tristimulus - * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8 - * derived values were recorded in the cHRM chunk; - * (red,green,blue,white)x(x,y). This loses one degree of freedom and - * therefore an arbitrary ninth value has to be introduced to undo the - * original transformations. - * - * Think of the original end-points as points in (X,Y,Z) space. The - * chromaticity values (c) have the property: - * - * C - * c = --------- - * X + Y + Z - * - * For each c (x,y,z) from the corresponding original C (X,Y,Z). Thus the - * three chromaticity values (x,y,z) for each end-point obey the - * relationship: - * - * x + y + z = 1 - * - * This describes the plane in (X,Y,Z) space that intersects each axis at the - * value 1.0; call this the chromaticity plane. Thus the chromaticity - * calculation has scaled each end-point so that it is on the x+y+z=1 plane - * and chromaticity is the intersection of the vector from the origin to the - * (X,Y,Z) value with the chromaticity plane. - * - * To fully invert the chromaticity calculation we would need the three - * end-point scale factors, (red-scale, green-scale, blue-scale), but these - * were not recorded. Instead we calculated the reference white (X,Y,Z) and - * recorded the chromaticity of this. The reference white (X,Y,Z) would have - * given all three of the scale factors since: - * - * color-C = color-c * color-scale - * white-C = red-C + green-C + blue-C - * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale - * - * But cHRM records only white-x and white-y, so we have lost the white scale - * factor: - * - * white-C = white-c*white-scale - * - * To handle this the inverse transformation makes an arbitrary assumption - * about white-scale: - * - * Assume: white-Y = 1.0 - * Hence: white-scale = 1/white-y - * Or: red-Y + green-Y + blue-Y = 1.0 - * - * Notice the last statement of the assumption gives an equation in three of - * the nine values we want to calculate. 8 more equations come from the - * above routine as summarised at the top above (the chromaticity - * calculation): - * - * Given: color-x = color-X / (color-X + color-Y + color-Z) - * Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0 - * - * This is 9 simultaneous equations in the 9 variables "color-C" and can be - * solved by Cramer's rule. Cramer's rule requires calculating 10 9x9 matrix - * determinants, however this is not as bad as it seems because only 28 of - * the total of 90 terms in the various matrices are non-zero. Nevertheless - * Cramer's rule is notoriously numerically unstable because the determinant - * calculation involves the difference of large, but similar, numbers. It is - * difficult to be sure that the calculation is stable for real world values - * and it is certain that it becomes unstable where the end points are close - * together. - * - * So this code uses the perhaps slightly less optimal but more - * understandable and totally obvious approach of calculating color-scale. - * - * This algorithm depends on the precision in white-scale and that is - * (1/white-y), so we can immediately see that as white-y approaches 0 the - * accuracy inherent in the cHRM chunk drops off substantially. - * - * libpng arithmetic: a simple inversion of the above equations - * ------------------------------------------------------------ - * - * white_scale = 1/white-y - * white-X = white-x * white-scale - * white-Y = 1.0 - * white-Z = (1 - white-x - white-y) * white_scale - * - * white-C = red-C + green-C + blue-C - * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale - * - * This gives us three equations in (red-scale,green-scale,blue-scale) where - * all the coefficients are now known: - * - * red-x*red-scale + green-x*green-scale + blue-x*blue-scale - * = white-x/white-y - * red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1 - * red-z*red-scale + green-z*green-scale + blue-z*blue-scale - * = (1 - white-x - white-y)/white-y - * - * In the last equation color-z is (1 - color-x - color-y) so we can add all - * three equations together to get an alternative third: - * - * red-scale + green-scale + blue-scale = 1/white-y = white-scale - * - * So now we have a Cramer's rule solution where the determinants are just - * 3x3 - far more tractible. Unfortunately 3x3 determinants still involve - * multiplication of three coefficients so we can't guarantee to avoid - * overflow in the libpng fixed point representation. Using Cramer's rule in - * floating point is probably a good choice here, but it's not an option for - * fixed point. Instead proceed to simplify the first two equations by - * eliminating what is likely to be the largest value, blue-scale: - * - * blue-scale = white-scale - red-scale - green-scale - * - * Hence: - * - * (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale = - * (white-x - blue-x)*white-scale - * - * (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale = - * 1 - blue-y*white-scale - * - * And now we can trivially solve for (red-scale,green-scale): - * - * green-scale = - * (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale - * ----------------------------------------------------------- - * green-x - blue-x - * - * red-scale = - * 1 - blue-y*white-scale - (green-y - blue-y) * green-scale - * --------------------------------------------------------- - * red-y - blue-y - * - * Hence: - * - * red-scale = - * ( (green-x - blue-x) * (white-y - blue-y) - - * (green-y - blue-y) * (white-x - blue-x) ) / white-y - * ------------------------------------------------------------------------- - * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x) - * - * green-scale = - * ( (red-y - blue-y) * (white-x - blue-x) - - * (red-x - blue-x) * (white-y - blue-y) ) / white-y - * ------------------------------------------------------------------------- - * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x) - * - * Accuracy: - * The input values have 5 decimal digits of accuracy. The values are all in - * the range 0 < value < 1, so simple products are in the same range but may - * need up to 10 decimal digits to preserve the original precision and avoid - * underflow. Because we are using a 32-bit signed representation we cannot - * match this; the best is a little over 9 decimal digits, less than 10. - * - * The approach used here is to preserve the maximum precision within the - * signed representation. Because the red-scale calculation above uses the - * difference between two products of values that must be in the range -1..+1 - * it is sufficient to divide the product by 7; ceil(100,000/32767*2). The - * factor is irrelevant in the calculation because it is applied to both - * numerator and denominator. - * - * Note that the values of the differences of the products of the - * chromaticities in the above equations tend to be small, for example for - * the sRGB chromaticities they are: - * - * red numerator: -0.04751 - * green numerator: -0.08788 - * denominator: -0.2241 (without white-y multiplication) - * - * The resultant Y coefficients from the chromaticities of some widely used - * color space definitions are (to 15 decimal places): - * - * sRGB - * 0.212639005871510 0.715168678767756 0.072192315360734 - * Kodak ProPhoto - * 0.288071128229293 0.711843217810102 0.000085653960605 - * Adobe RGB - * 0.297344975250536 0.627363566255466 0.075291458493998 - * Adobe Wide Gamut RGB - * 0.258728243040113 0.724682314948566 0.016589442011321 - */ - /* By the argument, above overflow should be impossible here. The return - * value of 2 indicates an internal error to the caller. - */ - if (png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 7) == 0) - return 2; - if (png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 7) == 0) - return 2; - denominator = left - right; - - /* Now find the red numerator. */ - if (png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 7) == 0) - return 2; - if (png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 7) == 0) - return 2; - - /* Overflow is possible here and it indicates an extreme set of PNG cHRM - * chunk values. This calculation actually returns the reciprocal of the - * scale value because this allows us to delay the multiplication of white-y - * into the denominator, which tends to produce a small number. - */ - if (png_muldiv(&red_inverse, xy->whitey, denominator, left-right) == 0 || - red_inverse <= xy->whitey /* r+g+b scales = white scale */) - return 1; - - /* Similarly for green_inverse: */ - if (png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 7) == 0) - return 2; - if (png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 7) == 0) - return 2; - if (png_muldiv(&green_inverse, xy->whitey, denominator, left-right) == 0 || - green_inverse <= xy->whitey) - return 1; - - /* And the blue scale, the checks above guarantee this can't overflow but it - * can still produce 0 for extreme cHRM values. - */ - blue_scale = png_reciprocal(xy->whitey) - png_reciprocal(red_inverse) - - png_reciprocal(green_inverse); - if (blue_scale <= 0) - return 1; - - - /* And fill in the png_XYZ: */ - if (png_muldiv(&XYZ->red_X, xy->redx, PNG_FP_1, red_inverse) == 0) - return 1; - if (png_muldiv(&XYZ->red_Y, xy->redy, PNG_FP_1, red_inverse) == 0) - return 1; - if (png_muldiv(&XYZ->red_Z, PNG_FP_1 - xy->redx - xy->redy, PNG_FP_1, - red_inverse) == 0) - return 1; - - if (png_muldiv(&XYZ->green_X, xy->greenx, PNG_FP_1, green_inverse) == 0) - return 1; - if (png_muldiv(&XYZ->green_Y, xy->greeny, PNG_FP_1, green_inverse) == 0) - return 1; - if (png_muldiv(&XYZ->green_Z, PNG_FP_1 - xy->greenx - xy->greeny, PNG_FP_1, - green_inverse) == 0) - return 1; - - if (png_muldiv(&XYZ->blue_X, xy->bluex, blue_scale, PNG_FP_1) == 0) - return 1; - if (png_muldiv(&XYZ->blue_Y, xy->bluey, blue_scale, PNG_FP_1) == 0) - return 1; - if (png_muldiv(&XYZ->blue_Z, PNG_FP_1 - xy->bluex - xy->bluey, blue_scale, - PNG_FP_1) == 0) - return 1; - - return 0; /*success*/ -} - -static int -png_XYZ_normalize(png_XYZ *XYZ) -{ - png_int_32 Y; - - if (XYZ->red_Y < 0 || XYZ->green_Y < 0 || XYZ->blue_Y < 0 || - XYZ->red_X < 0 || XYZ->green_X < 0 || XYZ->blue_X < 0 || - XYZ->red_Z < 0 || XYZ->green_Z < 0 || XYZ->blue_Z < 0) - return 1; - - /* Normalize by scaling so the sum of the end-point Y values is PNG_FP_1. - * IMPLEMENTATION NOTE: ANSI requires signed overflow not to occur, therefore - * relying on addition of two positive values producing a negative one is not - * safe. - */ - Y = XYZ->red_Y; - if (0x7fffffff - Y < XYZ->green_X) - return 1; - Y += XYZ->green_Y; - if (0x7fffffff - Y < XYZ->blue_X) - return 1; - Y += XYZ->blue_Y; - - if (Y != PNG_FP_1) - { - if (png_muldiv(&XYZ->red_X, XYZ->red_X, PNG_FP_1, Y) == 0) - return 1; - if (png_muldiv(&XYZ->red_Y, XYZ->red_Y, PNG_FP_1, Y) == 0) - return 1; - if (png_muldiv(&XYZ->red_Z, XYZ->red_Z, PNG_FP_1, Y) == 0) - return 1; - - if (png_muldiv(&XYZ->green_X, XYZ->green_X, PNG_FP_1, Y) == 0) - return 1; - if (png_muldiv(&XYZ->green_Y, XYZ->green_Y, PNG_FP_1, Y) == 0) - return 1; - if (png_muldiv(&XYZ->green_Z, XYZ->green_Z, PNG_FP_1, Y) == 0) - return 1; - - if (png_muldiv(&XYZ->blue_X, XYZ->blue_X, PNG_FP_1, Y) == 0) - return 1; - if (png_muldiv(&XYZ->blue_Y, XYZ->blue_Y, PNG_FP_1, Y) == 0) - return 1; - if (png_muldiv(&XYZ->blue_Z, XYZ->blue_Z, PNG_FP_1, Y) == 0) - return 1; - } - - return 0; -} - -static int -png_colorspace_endpoints_match(const png_xy *xy1, const png_xy *xy2, int delta) -{ - /* Allow an error of +/-0.01 (absolute value) on each chromaticity */ - if (PNG_OUT_OF_RANGE(xy1->whitex, xy2->whitex,delta) || - PNG_OUT_OF_RANGE(xy1->whitey, xy2->whitey,delta) || - PNG_OUT_OF_RANGE(xy1->redx, xy2->redx, delta) || - PNG_OUT_OF_RANGE(xy1->redy, xy2->redy, delta) || - PNG_OUT_OF_RANGE(xy1->greenx, xy2->greenx,delta) || - PNG_OUT_OF_RANGE(xy1->greeny, xy2->greeny,delta) || - PNG_OUT_OF_RANGE(xy1->bluex, xy2->bluex, delta) || - PNG_OUT_OF_RANGE(xy1->bluey, xy2->bluey, delta)) - return 0; - return 1; -} - -/* Added in libpng-1.6.0, a different check for the validity of a set of cHRM - * chunk chromaticities. Earlier checks used to simply look for the overflow - * condition (where the determinant of the matrix to solve for XYZ ends up zero - * because the chromaticity values are not all distinct.) Despite this it is - * theoretically possible to produce chromaticities that are apparently valid - * but that rapidly degrade to invalid, potentially crashing, sets because of - * arithmetic inaccuracies when calculations are performed on them. The new - * check is to round-trip xy -> XYZ -> xy and then check that the result is - * within a small percentage of the original. - */ -static int -png_colorspace_check_xy(png_XYZ *XYZ, const png_xy *xy) -{ - int result; - png_xy xy_test; - - /* As a side-effect this routine also returns the XYZ endpoints. */ - result = png_XYZ_from_xy(XYZ, xy); - if (result != 0) - return result; - - result = png_xy_from_XYZ(&xy_test, XYZ); - if (result != 0) - return result; - - if (png_colorspace_endpoints_match(xy, &xy_test, - 5/*actually, the math is pretty accurate*/) != 0) - return 0; - - /* Too much slip */ - return 1; -} - -/* This is the check going the other way. The XYZ is modified to normalize it - * (another side-effect) and the xy chromaticities are returned. - */ -static int -png_colorspace_check_XYZ(png_xy *xy, png_XYZ *XYZ) -{ - int result; - png_XYZ XYZtemp; - - result = png_XYZ_normalize(XYZ); - if (result != 0) - return result; - - result = png_xy_from_XYZ(xy, XYZ); - if (result != 0) - return result; - - XYZtemp = *XYZ; - return png_colorspace_check_xy(&XYZtemp, xy); -} - -/* Used to check for an endpoint match against sRGB */ -static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */ -{ - /* color x y */ - /* red */ 64000, 33000, - /* green */ 30000, 60000, - /* blue */ 15000, 6000, - /* white */ 31270, 32900 -}; - -static int -png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr, - png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ, - int preferred) -{ - if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) - return 0; - - /* The consistency check is performed on the chromaticities; this factors out - * variations because of the normalization (or not) of the end point Y - * values. - */ - if (preferred < 2 && - (colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) - { - /* The end points must be reasonably close to any we already have. The - * following allows an error of up to +/-.001 - */ - if (png_colorspace_endpoints_match(xy, &colorspace->end_points_xy, - 100) == 0) - { - colorspace->flags |= PNG_COLORSPACE_INVALID; - png_benign_error(png_ptr, "inconsistent chromaticities"); - return 0; /* failed */ - } - - /* Only overwrite with preferred values */ - if (preferred == 0) - return 1; /* ok, but no change */ - } - - colorspace->end_points_xy = *xy; - colorspace->end_points_XYZ = *XYZ; - colorspace->flags |= PNG_COLORSPACE_HAVE_ENDPOINTS; - - /* The end points are normally quoted to two decimal digits, so allow +/-0.01 - * on this test. - */ - if (png_colorspace_endpoints_match(xy, &sRGB_xy, 1000) != 0) - colorspace->flags |= PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB; - - else - colorspace->flags &= PNG_COLORSPACE_CANCEL( - PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB); - - return 2; /* ok and changed */ -} - -int /* PRIVATE */ -png_colorspace_set_chromaticities(png_const_structrp png_ptr, - png_colorspacerp colorspace, const png_xy *xy, int preferred) -{ - /* We must check the end points to ensure they are reasonable - in the past - * color management systems have crashed as a result of getting bogus - * colorant values, while this isn't the fault of libpng it is the - * responsibility of libpng because PNG carries the bomb and libpng is in a - * position to protect against it. - */ - png_XYZ XYZ; - - switch (png_colorspace_check_xy(&XYZ, xy)) - { - case 0: /* success */ - return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ, - preferred); - - case 1: - /* We can't invert the chromaticities so we can't produce value XYZ - * values. Likely as not a color management system will fail too. - */ - colorspace->flags |= PNG_COLORSPACE_INVALID; - png_benign_error(png_ptr, "invalid chromaticities"); - break; - - default: - /* libpng is broken; this should be a warning but if it happens we - * want error reports so for the moment it is an error. - */ - colorspace->flags |= PNG_COLORSPACE_INVALID; - png_error(png_ptr, "internal error checking chromaticities"); - } - - return 0; /* failed */ -} - -int /* PRIVATE */ -png_colorspace_set_endpoints(png_const_structrp png_ptr, - png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred) -{ - png_XYZ XYZ = *XYZ_in; - png_xy xy; - - switch (png_colorspace_check_XYZ(&xy, &XYZ)) - { - case 0: - return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ, - preferred); - - case 1: - /* End points are invalid. */ - colorspace->flags |= PNG_COLORSPACE_INVALID; - png_benign_error(png_ptr, "invalid end points"); - break; - - default: - colorspace->flags |= PNG_COLORSPACE_INVALID; - png_error(png_ptr, "internal error checking chromaticities"); - } - - return 0; /* failed */ -} - -#if defined(PNG_sRGB_SUPPORTED) || defined(PNG_iCCP_SUPPORTED) -/* Error message generation */ -static char -png_icc_tag_char(png_uint_32 byte) -{ - byte &= 0xff; - if (byte >= 32 && byte <= 126) - return (char)byte; - else - return '?'; -} - -static void -png_icc_tag_name(char *name, png_uint_32 tag) -{ - name[0] = '\''; - name[1] = png_icc_tag_char(tag >> 24); - name[2] = png_icc_tag_char(tag >> 16); - name[3] = png_icc_tag_char(tag >> 8); - name[4] = png_icc_tag_char(tag ); - name[5] = '\''; -} - -static int -is_ICC_signature_char(png_alloc_size_t it) -{ - return it == 32 || (it >= 48 && it <= 57) || (it >= 65 && it <= 90) || - (it >= 97 && it <= 122); -} - -static int -is_ICC_signature(png_alloc_size_t it) -{ - return is_ICC_signature_char(it >> 24) /* checks all the top bits */ && - is_ICC_signature_char((it >> 16) & 0xff) && - is_ICC_signature_char((it >> 8) & 0xff) && - is_ICC_signature_char(it & 0xff); -} - -static int -png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_alloc_size_t value, png_const_charp reason) -{ - size_t pos; - char message[196]; /* see below for calculation */ - - if (colorspace != NULL) - colorspace->flags |= PNG_COLORSPACE_INVALID; - - pos = png_safecat(message, (sizeof message), 0, "profile '"); /* 9 chars */ - pos = png_safecat(message, pos+79, pos, name); /* Truncate to 79 chars */ - pos = png_safecat(message, (sizeof message), pos, "': "); /* +2 = 90 */ - if (is_ICC_signature(value) != 0) - { - /* So 'value' is at most 4 bytes and the following cast is safe */ - png_icc_tag_name(message+pos, (png_uint_32)value); - pos += 6; /* total +8; less than the else clause */ - message[pos++] = ':'; - message[pos++] = ' '; - } -# ifdef PNG_WARNINGS_SUPPORTED - else - { - char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/ - - pos = png_safecat(message, (sizeof message), pos, - png_format_number(number, number+(sizeof number), - PNG_NUMBER_FORMAT_x, value)); - pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/ - } -# endif - /* The 'reason' is an arbitrary message, allow +79 maximum 195 */ - pos = png_safecat(message, (sizeof message), pos, reason); - PNG_UNUSED(pos) - - /* This is recoverable, but make it unconditionally an app_error on write to - * avoid writing invalid ICC profiles into PNG files (i.e., we handle them - * on read, with a warning, but on write unless the app turns off - * application errors the PNG won't be written.) - */ - png_chunk_report(png_ptr, message, - (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR); - - return 0; -} -#endif /* sRGB || iCCP */ - -#ifdef PNG_sRGB_SUPPORTED -int /* PRIVATE */ -png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace, - int intent) -{ - /* sRGB sets known gamma, end points and (from the chunk) intent. */ - /* IMPORTANT: these are not necessarily the values found in an ICC profile - * because ICC profiles store values adapted to a D50 environment; it is - * expected that the ICC profile mediaWhitePointTag will be D50; see the - * checks and code elsewhere to understand this better. - * - * These XYZ values, which are accurate to 5dp, produce rgb to gray - * coefficients of (6968,23435,2366), which are reduced (because they add up - * to 32769 not 32768) to (6968,23434,2366). These are the values that - * libpng has traditionally used (and are the best values given the 15bit - * algorithm used by the rgb to gray code.) - */ - static const png_XYZ sRGB_XYZ = /* D65 XYZ (*not* the D50 adapted values!) */ - { - /* color X Y Z */ - /* red */ 41239, 21264, 1933, - /* green */ 35758, 71517, 11919, - /* blue */ 18048, 7219, 95053 - }; - - /* Do nothing if the colorspace is already invalidated. */ - if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) - return 0; - - /* Check the intent, then check for existing settings. It is valid for the - * PNG file to have cHRM or gAMA chunks along with sRGB, but the values must - * be consistent with the correct values. If, however, this function is - * called below because an iCCP chunk matches sRGB then it is quite - * conceivable that an older app recorded incorrect gAMA and cHRM because of - * an incorrect calculation based on the values in the profile - this does - * *not* invalidate the profile (though it still produces an error, which can - * be ignored.) - */ - if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST) - return png_icc_profile_error(png_ptr, colorspace, "sRGB", - (unsigned)intent, "invalid sRGB rendering intent"); - - if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 && - colorspace->rendering_intent != intent) - return png_icc_profile_error(png_ptr, colorspace, "sRGB", - (unsigned)intent, "inconsistent rendering intents"); - - if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0) - { - png_benign_error(png_ptr, "duplicate sRGB information ignored"); - return 0; - } - - /* If the standard sRGB cHRM chunk does not match the one from the PNG file - * warn but overwrite the value with the correct one. - */ - if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 && - !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy, - 100)) - png_chunk_report(png_ptr, "cHRM chunk does not match sRGB", - PNG_CHUNK_ERROR); - - /* This check is just done for the error reporting - the routine always - * returns true when the 'from' argument corresponds to sRGB (2). - */ - (void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE, - 2/*from sRGB*/); - - /* intent: bugs in GCC force 'int' to be used as the parameter type. */ - colorspace->rendering_intent = (png_uint_16)intent; - colorspace->flags |= PNG_COLORSPACE_HAVE_INTENT; - - /* endpoints */ - colorspace->end_points_xy = sRGB_xy; - colorspace->end_points_XYZ = sRGB_XYZ; - colorspace->flags |= - (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB); - - /* gamma */ - colorspace->gamma = PNG_GAMMA_sRGB_INVERSE; - colorspace->flags |= PNG_COLORSPACE_HAVE_GAMMA; - - /* Finally record that we have an sRGB profile */ - colorspace->flags |= - (PNG_COLORSPACE_MATCHES_sRGB|PNG_COLORSPACE_FROM_sRGB); - - return 1; /* set */ -} -#endif /* sRGB */ - -#ifdef PNG_iCCP_SUPPORTED -/* Encoded value of D50 as an ICC XYZNumber. From the ICC 2010 spec the value - * is XYZ(0.9642,1.0,0.8249), which scales to: - * - * (63189.8112, 65536, 54060.6464) - */ -static const png_byte D50_nCIEXYZ[12] = - { 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d }; - -int /* PRIVATE */ -png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_uint_32 profile_length) -{ - if (profile_length < 132) - return png_icc_profile_error(png_ptr, colorspace, name, profile_length, - "too short"); - - return 1; -} - -int /* PRIVATE */ -png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_uint_32 profile_length, - png_const_bytep profile/* first 132 bytes only */, int color_type) -{ - png_uint_32 temp; - - /* Length check; this cannot be ignored in this code because profile_length - * is used later to check the tag table, so even if the profile seems over - * long profile_length from the caller must be correct. The caller can fix - * this up on read or write by just passing in the profile header length. - */ - temp = png_get_uint_32(profile); - if (temp != profile_length) - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "length does not match profile"); - - temp = (png_uint_32) (*(profile+8)); - if (temp > 3 && (profile_length & 3)) - return png_icc_profile_error(png_ptr, colorspace, name, profile_length, - "invalid length"); - - temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */ - if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */ - profile_length < 132+12*temp) /* truncated tag table */ - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "tag count too large"); - - /* The 'intent' must be valid or we can't store it, ICC limits the intent to - * 16 bits. - */ - temp = png_get_uint_32(profile+64); - if (temp >= 0xffff) /* The ICC limit */ - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "invalid rendering intent"); - - /* This is just a warning because the profile may be valid in future - * versions. - */ - if (temp >= PNG_sRGB_INTENT_LAST) - (void)png_icc_profile_error(png_ptr, NULL, name, temp, - "intent outside defined range"); - - /* At this point the tag table can't be checked because it hasn't necessarily - * been loaded; however, various header fields can be checked. These checks - * are for values permitted by the PNG spec in an ICC profile; the PNG spec - * restricts the profiles that can be passed in an iCCP chunk (they must be - * appropriate to processing PNG data!) - */ - - /* Data checks (could be skipped). These checks must be independent of the - * version number; however, the version number doesn't accomodate changes in - * the header fields (just the known tags and the interpretation of the - * data.) - */ - temp = png_get_uint_32(profile+36); /* signature 'ascp' */ - if (temp != 0x61637370) - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "invalid signature"); - - /* Currently the PCS illuminant/adopted white point (the computational - * white point) are required to be D50, - * however the profile contains a record of the illuminant so perhaps ICC - * expects to be able to change this in the future (despite the rationale in - * the introduction for using a fixed PCS adopted white.) Consequently the - * following is just a warning. - */ - if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0) - (void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/, - "PCS illuminant is not D50"); - - /* The PNG spec requires this: - * "If the iCCP chunk is present, the image samples conform to the colour - * space represented by the embedded ICC profile as defined by the - * International Color Consortium [ICC]. The colour space of the ICC profile - * shall be an RGB colour space for colour images (PNG colour types 2, 3, and - * 6), or a greyscale colour space for greyscale images (PNG colour types 0 - * and 4)." - * - * This checking code ensures the embedded profile (on either read or write) - * conforms to the specification requirements. Notice that an ICC 'gray' - * color-space profile contains the information to transform the monochrome - * data to XYZ or L*a*b (according to which PCS the profile uses) and this - * should be used in preference to the standard libpng K channel replication - * into R, G and B channels. - * - * Previously it was suggested that an RGB profile on grayscale data could be - * handled. However it it is clear that using an RGB profile in this context - * must be an error - there is no specification of what it means. Thus it is - * almost certainly more correct to ignore the profile. - */ - temp = png_get_uint_32(profile+16); /* data colour space field */ - switch (temp) - { - case 0x52474220: /* 'RGB ' */ - if ((color_type & PNG_COLOR_MASK_COLOR) == 0) - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "RGB color space not permitted on grayscale PNG"); - break; - - case 0x47524159: /* 'GRAY' */ - if ((color_type & PNG_COLOR_MASK_COLOR) != 0) - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "Gray color space not permitted on RGB PNG"); - break; - - default: - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "invalid ICC profile color space"); - } - - /* It is up to the application to check that the profile class matches the - * application requirements; the spec provides no guidance, but it's pretty - * weird if the profile is not scanner ('scnr'), monitor ('mntr'), printer - * ('prtr') or 'spac' (for generic color spaces). Issue a warning in these - * cases. Issue an error for device link or abstract profiles - these don't - * contain the records necessary to transform the color-space to anything - * other than the target device (and not even that for an abstract profile). - * Profiles of these classes may not be embedded in images. - */ - temp = png_get_uint_32(profile+12); /* profile/device class */ - switch (temp) - { - case 0x73636e72: /* 'scnr' */ - case 0x6d6e7472: /* 'mntr' */ - case 0x70727472: /* 'prtr' */ - case 0x73706163: /* 'spac' */ - /* All supported */ - break; - - case 0x61627374: /* 'abst' */ - /* May not be embedded in an image */ - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "invalid embedded Abstract ICC profile"); - - case 0x6c696e6b: /* 'link' */ - /* DeviceLink profiles cannot be interpreted in a non-device specific - * fashion, if an app uses the AToB0Tag in the profile the results are - * undefined unless the result is sent to the intended device, - * therefore a DeviceLink profile should not be found embedded in a - * PNG. - */ - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "unexpected DeviceLink ICC profile class"); - - case 0x6e6d636c: /* 'nmcl' */ - /* A NamedColor profile is also device specific, however it doesn't - * contain an AToB0 tag that is open to misinterpretation. Almost - * certainly it will fail the tests below. - */ - (void)png_icc_profile_error(png_ptr, NULL, name, temp, - "unexpected NamedColor ICC profile class"); - break; - - default: - /* To allow for future enhancements to the profile accept unrecognized - * profile classes with a warning, these then hit the test below on the - * tag content to ensure they are backward compatible with one of the - * understood profiles. - */ - (void)png_icc_profile_error(png_ptr, NULL, name, temp, - "unrecognized ICC profile class"); - break; - } - - /* For any profile other than a device link one the PCS must be encoded - * either in XYZ or Lab. - */ - temp = png_get_uint_32(profile+20); - switch (temp) - { - case 0x58595a20: /* 'XYZ ' */ - case 0x4c616220: /* 'Lab ' */ - break; - - default: - return png_icc_profile_error(png_ptr, colorspace, name, temp, - "unexpected ICC PCS encoding"); - } - - return 1; -} - -int /* PRIVATE */ -png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_uint_32 profile_length, - png_const_bytep profile /* header plus whole tag table */) -{ - png_uint_32 tag_count = png_get_uint_32(profile+128); - png_uint_32 itag; - png_const_bytep tag = profile+132; /* The first tag */ - - /* First scan all the tags in the table and add bits to the icc_info value - * (temporarily in 'tags'). - */ - for (itag=0; itag < tag_count; ++itag, tag += 12) - { - png_uint_32 tag_id = png_get_uint_32(tag+0); - png_uint_32 tag_start = png_get_uint_32(tag+4); /* must be aligned */ - png_uint_32 tag_length = png_get_uint_32(tag+8);/* not padded */ - - /* The ICC specification does not exclude zero length tags, therefore the - * start might actually be anywhere if there is no data, but this would be - * a clear abuse of the intent of the standard so the start is checked for - * being in range. All defined tag types have an 8 byte header - a 4 byte - * type signature then 0. - */ - if ((tag_start & 3) != 0) - { - /* CNHP730S.icc shipped with Microsoft Windows 64 violates this, it is - * only a warning here because libpng does not care about the - * alignment. - */ - (void)png_icc_profile_error(png_ptr, NULL, name, tag_id, - "ICC profile tag start not a multiple of 4"); - } - - /* This is a hard error; potentially it can cause read outside the - * profile. - */ - if (tag_start > profile_length || tag_length > profile_length - tag_start) - return png_icc_profile_error(png_ptr, colorspace, name, tag_id, - "ICC profile tag outside profile"); - } - - return 1; /* success, maybe with warnings */ -} - -#ifdef PNG_sRGB_SUPPORTED -#if PNG_sRGB_PROFILE_CHECKS >= 0 -/* Information about the known ICC sRGB profiles */ -static const struct -{ - png_uint_32 adler, crc, length; - png_uint_32 md5[4]; - png_byte have_md5; - png_byte is_broken; - png_uint_16 intent; - -# define PNG_MD5(a,b,c,d) { a, b, c, d }, (a!=0)||(b!=0)||(c!=0)||(d!=0) -# define PNG_ICC_CHECKSUM(adler, crc, md5, intent, broke, date, length, fname)\ - { adler, crc, length, md5, broke, intent }, - -} png_sRGB_checks[] = -{ - /* This data comes from contrib/tools/checksum-icc run on downloads of - * all four ICC sRGB profiles from www.color.org. - */ - /* adler32, crc32, MD5[4], intent, date, length, file-name */ - PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9, - PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0, - "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc") - - /* ICC sRGB v2 perceptual no black-compensation: */ - PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21, - PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0, - "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc") - - PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae, - PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0, - "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc") - - /* ICC sRGB v4 perceptual */ - PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812, - PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0, - "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc") - - /* The following profiles have no known MD5 checksum. If there is a match - * on the (empty) MD5 the other fields are used to attempt a match and - * a warning is produced. The first two of these profiles have a 'cprt' tag - * which suggests that they were also made by Hewlett Packard. - */ - PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce, - PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0, - "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc") - - /* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not - * match the D50 PCS illuminant in the header (it is in fact the D65 values, - * so the white point is recorded as the un-adapted value.) The profiles - * below only differ in one byte - the intent - and are basically the same as - * the previous profile except for the mediaWhitePointTag error and a missing - * chromaticAdaptationTag. - */ - PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552, - PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/, - "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual") - - PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d, - PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/, - "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative") -}; - -static int -png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr, - png_const_bytep profile, uLong adler) -{ - /* The quick check is to verify just the MD5 signature and trust the - * rest of the data. Because the profile has already been verified for - * correctness this is safe. png_colorspace_set_sRGB will check the 'intent' - * field too, so if the profile has been edited with an intent not defined - * by sRGB (but maybe defined by a later ICC specification) the read of - * the profile will fail at that point. - */ - - png_uint_32 length = 0; - png_uint_32 intent = 0x10000; /* invalid */ -#if PNG_sRGB_PROFILE_CHECKS > 1 - uLong crc = 0; /* the value for 0 length data */ -#endif - unsigned int i; - -#ifdef PNG_SET_OPTION_SUPPORTED - /* First see if PNG_SKIP_sRGB_CHECK_PROFILE has been set to "on" */ - if (((png_ptr->options >> PNG_SKIP_sRGB_CHECK_PROFILE) & 3) == - PNG_OPTION_ON) - return 0; -#endif - - for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i) - { - if (png_get_uint_32(profile+84) == png_sRGB_checks[i].md5[0] && - png_get_uint_32(profile+88) == png_sRGB_checks[i].md5[1] && - png_get_uint_32(profile+92) == png_sRGB_checks[i].md5[2] && - png_get_uint_32(profile+96) == png_sRGB_checks[i].md5[3]) - { - /* This may be one of the old HP profiles without an MD5, in that - * case we can only use the length and Adler32 (note that these - * are not used by default if there is an MD5!) - */ -# if PNG_sRGB_PROFILE_CHECKS == 0 - if (png_sRGB_checks[i].have_md5 != 0) - return 1+png_sRGB_checks[i].is_broken; -# endif - - /* Profile is unsigned or more checks have been configured in. */ - if (length == 0) - { - length = png_get_uint_32(profile); - intent = png_get_uint_32(profile+64); - } - - /* Length *and* intent must match */ - if (length == (png_uint_32) png_sRGB_checks[i].length && - intent == (png_uint_32) png_sRGB_checks[i].intent) - { - /* Now calculate the adler32 if not done already. */ - if (adler == 0) - { - adler = adler32(0, NULL, 0); - adler = adler32(adler, profile, length); - } - - if (adler == png_sRGB_checks[i].adler) - { - /* These basic checks suggest that the data has not been - * modified, but if the check level is more than 1 perform - * our own crc32 checksum on the data. - */ -# if PNG_sRGB_PROFILE_CHECKS > 1 - if (crc == 0) - { - crc = crc32(0, NULL, 0); - crc = crc32(crc, profile, length); - } - - /* So this check must pass for the 'return' below to happen. - */ - if (crc == png_sRGB_checks[i].crc) -# endif - { - if (png_sRGB_checks[i].is_broken != 0) - { - /* These profiles are known to have bad data that may cause - * problems if they are used, therefore attempt to - * discourage their use, skip the 'have_md5' warning below, - * which is made irrelevant by this error. - */ - png_chunk_report(png_ptr, "known incorrect sRGB profile", - PNG_CHUNK_ERROR); - } - - /* Warn that this being done; this isn't even an error since - * the profile is perfectly valid, but it would be nice if - * people used the up-to-date ones. - */ - else if (png_sRGB_checks[i].have_md5 == 0) - { - png_chunk_report(png_ptr, - "out-of-date sRGB profile with no signature", - PNG_CHUNK_WARNING); - } - - return 1+png_sRGB_checks[i].is_broken; - } - } - -# if PNG_sRGB_PROFILE_CHECKS > 0 - /* The signature matched, but the profile had been changed in some - * way. This probably indicates a data error or uninformed hacking. - * Fall through to "no match". - */ - png_chunk_report(png_ptr, - "Not recognizing known sRGB profile that has been edited", - PNG_CHUNK_WARNING); - break; -# endif - } - } - } - - return 0; /* no match */ -} -#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */ - -void /* PRIVATE */ -png_icc_set_sRGB(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_const_bytep profile, uLong adler) -{ - /* Is this profile one of the known ICC sRGB profiles? If it is, just set - * the sRGB information. - */ -#if PNG_sRGB_PROFILE_CHECKS >= 0 - if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0) -#endif - (void)png_colorspace_set_sRGB(png_ptr, colorspace, - (int)/*already checked*/png_get_uint_32(profile+64)); -} -#endif /* sRGB */ - -int /* PRIVATE */ -png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_charp name, png_uint_32 profile_length, png_const_bytep profile, - int color_type) -{ - if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) - return 0; - - if (png_icc_check_length(png_ptr, colorspace, name, profile_length) != 0 && - png_icc_check_header(png_ptr, colorspace, name, profile_length, profile, - color_type) != 0 && - png_icc_check_tag_table(png_ptr, colorspace, name, profile_length, - profile) != 0) - { -# ifdef PNG_sRGB_SUPPORTED - /* If no sRGB support, don't try storing sRGB information */ - png_icc_set_sRGB(png_ptr, colorspace, profile, 0); -# endif - return 1; - } - - /* Failure case */ - return 0; -} -#endif /* iCCP */ - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -void /* PRIVATE */ -png_colorspace_set_rgb_coefficients(png_structrp png_ptr) -{ - /* Set the rgb_to_gray coefficients from the colorspace. */ - if (png_ptr->rgb_to_gray_coefficients_set == 0 && - (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) - { - /* png_set_background has not been called, get the coefficients from the Y - * values of the colorspace colorants. - */ - png_fixed_point r = png_ptr->colorspace.end_points_XYZ.red_Y; - png_fixed_point g = png_ptr->colorspace.end_points_XYZ.green_Y; - png_fixed_point b = png_ptr->colorspace.end_points_XYZ.blue_Y; - png_fixed_point total = r+g+b; - - if (total > 0 && - r >= 0 && png_muldiv(&r, r, 32768, total) && r >= 0 && r <= 32768 && - g >= 0 && png_muldiv(&g, g, 32768, total) && g >= 0 && g <= 32768 && - b >= 0 && png_muldiv(&b, b, 32768, total) && b >= 0 && b <= 32768 && - r+g+b <= 32769) - { - /* We allow 0 coefficients here. r+g+b may be 32769 if two or - * all of the coefficients were rounded up. Handle this by - * reducing the *largest* coefficient by 1; this matches the - * approach used for the default coefficients in pngrtran.c - */ - int add = 0; - - if (r+g+b > 32768) - add = -1; - else if (r+g+b < 32768) - add = 1; - - if (add != 0) - { - if (g >= r && g >= b) - g += add; - else if (r >= g && r >= b) - r += add; - else - b += add; - } - - /* Check for an internal error. */ - if (r+g+b != 32768) - png_error(png_ptr, - "internal error handling cHRM coefficients"); - - else - { - png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r; - png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g; - } - } - - /* This is a png_error at present even though it could be ignored - - * it should never happen, but it is important that if it does, the - * bug is fixed. - */ - else - png_error(png_ptr, "internal error handling cHRM->XYZ"); - } -} -#endif /* READ_RGB_TO_GRAY */ - -#endif /* COLORSPACE */ - -#ifdef __GNUC__ -/* This exists solely to work round a warning from GNU C. */ -static int /* PRIVATE */ -png_gt(size_t a, size_t b) -{ - return a > b; -} -#else -# define png_gt(a,b) ((a) > (b)) -#endif - -void /* PRIVATE */ -png_check_IHDR(png_const_structrp png_ptr, - png_uint_32 width, png_uint_32 height, int bit_depth, - int color_type, int interlace_type, int compression_type, - int filter_type) -{ - int error = 0; - - /* Check for width and height valid values */ - if (width == 0) - { - png_warning(png_ptr, "Image width is zero in IHDR"); - error = 1; - } - - if (width > PNG_UINT_31_MAX) - { - png_warning(png_ptr, "Invalid image width in IHDR"); - error = 1; - } - - if (png_gt(((width + 7) & (~7)), - ((PNG_SIZE_MAX - - 48 /* big_row_buf hack */ - - 1) /* filter byte */ - / 8) /* 8-byte RGBA pixels */ - - 1)) /* extra max_pixel_depth pad */ - { - /* The size of the row must be within the limits of this architecture. - * Because the read code can perform arbitrary transformations the - * maximum size is checked here. Because the code in png_read_start_row - * adds extra space "for safety's sake" in several places a conservative - * limit is used here. - * - * NOTE: it would be far better to check the size that is actually used, - * but the effect in the real world is minor and the changes are more - * extensive, therefore much more dangerous and much more difficult to - * write in a way that avoids compiler warnings. - */ - png_warning(png_ptr, "Image width is too large for this architecture"); - error = 1; - } - -#ifdef PNG_SET_USER_LIMITS_SUPPORTED - if (width > png_ptr->user_width_max) -#else - if (width > PNG_USER_WIDTH_MAX) -#endif - { - png_warning(png_ptr, "Image width exceeds user limit in IHDR"); - error = 1; - } - - if (height == 0) - { - png_warning(png_ptr, "Image height is zero in IHDR"); - error = 1; - } - - if (height > PNG_UINT_31_MAX) - { - png_warning(png_ptr, "Invalid image height in IHDR"); - error = 1; - } - -#ifdef PNG_SET_USER_LIMITS_SUPPORTED - if (height > png_ptr->user_height_max) -#else - if (height > PNG_USER_HEIGHT_MAX) -#endif - { - png_warning(png_ptr, "Image height exceeds user limit in IHDR"); - error = 1; - } - - /* Check other values */ - if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 && - bit_depth != 8 && bit_depth != 16) - { - png_warning(png_ptr, "Invalid bit depth in IHDR"); - error = 1; - } - - if (color_type < 0 || color_type == 1 || - color_type == 5 || color_type > 6) - { - png_warning(png_ptr, "Invalid color type in IHDR"); - error = 1; - } - - if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) || - ((color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_GRAY_ALPHA || - color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8)) - { - png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR"); - error = 1; - } - - if (interlace_type >= PNG_INTERLACE_LAST) - { - png_warning(png_ptr, "Unknown interlace method in IHDR"); - error = 1; - } - - if (compression_type != PNG_COMPRESSION_TYPE_BASE) - { - png_warning(png_ptr, "Unknown compression method in IHDR"); - error = 1; - } - -#ifdef PNG_MNG_FEATURES_SUPPORTED - /* Accept filter_method 64 (intrapixel differencing) only if - * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and - * 2. Libpng did not read a PNG signature (this filter_method is only - * used in PNG datastreams that are embedded in MNG datastreams) and - * 3. The application called png_permit_mng_features with a mask that - * included PNG_FLAG_MNG_FILTER_64 and - * 4. The filter_method is 64 and - * 5. The color_type is RGB or RGBA - */ - if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && - png_ptr->mng_features_permitted != 0) - png_warning(png_ptr, "MNG features are not allowed in a PNG datastream"); - - if (filter_type != PNG_FILTER_TYPE_BASE) - { - if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && - (filter_type == PNG_INTRAPIXEL_DIFFERENCING) && - ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) && - (color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_RGB_ALPHA))) - { - png_warning(png_ptr, "Unknown filter method in IHDR"); - error = 1; - } - - if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0) - { - png_warning(png_ptr, "Invalid filter method in IHDR"); - error = 1; - } - } - -#else - if (filter_type != PNG_FILTER_TYPE_BASE) - { - png_warning(png_ptr, "Unknown filter method in IHDR"); - error = 1; - } -#endif - - if (error == 1) - png_error(png_ptr, "Invalid IHDR data"); -} - -#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) -/* ASCII to fp functions */ -/* Check an ASCII formated floating point value, see the more detailed - * comments in pngpriv.h - */ -/* The following is used internally to preserve the sticky flags */ -#define png_fp_add(state, flags) ((state) |= (flags)) -#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY)) - -int /* PRIVATE */ -png_check_fp_number(png_const_charp string, png_size_t size, int *statep, - png_size_tp whereami) -{ - int state = *statep; - png_size_t i = *whereami; - - while (i < size) - { - int type; - /* First find the type of the next character */ - switch (string[i]) - { - case 43: type = PNG_FP_SAW_SIGN; break; - case 45: type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break; - case 46: type = PNG_FP_SAW_DOT; break; - case 48: type = PNG_FP_SAW_DIGIT; break; - case 49: case 50: case 51: case 52: - case 53: case 54: case 55: case 56: - case 57: type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break; - case 69: - case 101: type = PNG_FP_SAW_E; break; - default: goto PNG_FP_End; - } - - /* Now deal with this type according to the current - * state, the type is arranged to not overlap the - * bits of the PNG_FP_STATE. - */ - switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY)) - { - case PNG_FP_INTEGER + PNG_FP_SAW_SIGN: - if ((state & PNG_FP_SAW_ANY) != 0) - goto PNG_FP_End; /* not a part of the number */ - - png_fp_add(state, type); - break; - - case PNG_FP_INTEGER + PNG_FP_SAW_DOT: - /* Ok as trailer, ok as lead of fraction. */ - if ((state & PNG_FP_SAW_DOT) != 0) /* two dots */ - goto PNG_FP_End; - - else if ((state & PNG_FP_SAW_DIGIT) != 0) /* trailing dot? */ - png_fp_add(state, type); - - else - png_fp_set(state, PNG_FP_FRACTION | type); - - break; - - case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT: - if ((state & PNG_FP_SAW_DOT) != 0) /* delayed fraction */ - png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT); - - png_fp_add(state, type | PNG_FP_WAS_VALID); - - break; - - case PNG_FP_INTEGER + PNG_FP_SAW_E: - if ((state & PNG_FP_SAW_DIGIT) == 0) - goto PNG_FP_End; - - png_fp_set(state, PNG_FP_EXPONENT); - - break; - - /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN: - goto PNG_FP_End; ** no sign in fraction */ - - /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT: - goto PNG_FP_End; ** Because SAW_DOT is always set */ - - case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT: - png_fp_add(state, type | PNG_FP_WAS_VALID); - break; - - case PNG_FP_FRACTION + PNG_FP_SAW_E: - /* This is correct because the trailing '.' on an - * integer is handled above - so we can only get here - * with the sequence ".E" (with no preceding digits). - */ - if ((state & PNG_FP_SAW_DIGIT) == 0) - goto PNG_FP_End; - - png_fp_set(state, PNG_FP_EXPONENT); - - break; - - case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN: - if ((state & PNG_FP_SAW_ANY) != 0) - goto PNG_FP_End; /* not a part of the number */ - - png_fp_add(state, PNG_FP_SAW_SIGN); - - break; - - /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT: - goto PNG_FP_End; */ - - case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT: - png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID); - - break; - - /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E: - goto PNG_FP_End; */ - - default: goto PNG_FP_End; /* I.e. break 2 */ - } - - /* The character seems ok, continue. */ - ++i; - } - -PNG_FP_End: - /* Here at the end, update the state and return the correct - * return code. - */ - *statep = state; - *whereami = i; - - return (state & PNG_FP_SAW_DIGIT) != 0; -} - - -/* The same but for a complete string. */ -int -png_check_fp_string(png_const_charp string, png_size_t size) -{ - int state=0; - png_size_t char_index=0; - - if (png_check_fp_number(string, size, &state, &char_index) != 0 && - (char_index == size || string[char_index] == 0)) - return state /* must be non-zero - see above */; - - return 0; /* i.e. fail */ -} -#endif /* pCAL || sCAL */ - -#ifdef PNG_sCAL_SUPPORTED -# ifdef PNG_FLOATING_POINT_SUPPORTED -/* Utility used below - a simple accurate power of ten from an integral - * exponent. - */ -static double -png_pow10(int power) -{ - int recip = 0; - double d = 1; - - /* Handle negative exponent with a reciprocal at the end because - * 10 is exact whereas .1 is inexact in base 2 - */ - if (power < 0) - { - if (power < DBL_MIN_10_EXP) return 0; - recip = 1, power = -power; - } - - if (power > 0) - { - /* Decompose power bitwise. */ - double mult = 10; - do - { - if (power & 1) d *= mult; - mult *= mult; - power >>= 1; - } - while (power > 0); - - if (recip != 0) d = 1/d; - } - /* else power is 0 and d is 1 */ - - return d; -} - -/* Function to format a floating point value in ASCII with a given - * precision. - */ -void /* PRIVATE */ -png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, - double fp, unsigned int precision) -{ - /* We use standard functions from math.h, but not printf because - * that would require stdio. The caller must supply a buffer of - * sufficient size or we will png_error. The tests on size and - * the space in ascii[] consumed are indicated below. - */ - if (precision < 1) - precision = DBL_DIG; - - /* Enforce the limit of the implementation precision too. */ - if (precision > DBL_DIG+1) - precision = DBL_DIG+1; - - /* Basic sanity checks */ - if (size >= precision+5) /* See the requirements below. */ - { - if (fp < 0) - { - fp = -fp; - *ascii++ = 45; /* '-' PLUS 1 TOTAL 1 */ - --size; - } - - if (fp >= DBL_MIN && fp <= DBL_MAX) - { - int exp_b10; /* A base 10 exponent */ - double base; /* 10^exp_b10 */ - - /* First extract a base 10 exponent of the number, - * the calculation below rounds down when converting - * from base 2 to base 10 (multiply by log10(2) - - * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to - * be increased. Note that the arithmetic shift - * performs a floor() unlike C arithmetic - using a - * C multiply would break the following for negative - * exponents. - */ - (void)frexp(fp, &exp_b10); /* exponent to base 2 */ - - exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */ - - /* Avoid underflow here. */ - base = png_pow10(exp_b10); /* May underflow */ - - while (base < DBL_MIN || base < fp) - { - /* And this may overflow. */ - double test = png_pow10(exp_b10+1); - - if (test <= DBL_MAX) - ++exp_b10, base = test; - - else - break; - } - - /* Normalize fp and correct exp_b10, after this fp is in the - * range [.1,1) and exp_b10 is both the exponent and the digit - * *before* which the decimal point should be inserted - * (starting with 0 for the first digit). Note that this - * works even if 10^exp_b10 is out of range because of the - * test on DBL_MAX above. - */ - fp /= base; - while (fp >= 1) fp /= 10, ++exp_b10; - - /* Because of the code above fp may, at this point, be - * less than .1, this is ok because the code below can - * handle the leading zeros this generates, so no attempt - * is made to correct that here. - */ - - { - unsigned int czero, clead, cdigits; - char exponent[10]; - - /* Allow up to two leading zeros - this will not lengthen - * the number compared to using E-n. - */ - if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */ - { - czero = -exp_b10; /* PLUS 2 digits: TOTAL 3 */ - exp_b10 = 0; /* Dot added below before first output. */ - } - else - czero = 0; /* No zeros to add */ - - /* Generate the digit list, stripping trailing zeros and - * inserting a '.' before a digit if the exponent is 0. - */ - clead = czero; /* Count of leading zeros */ - cdigits = 0; /* Count of digits in list. */ - - do - { - double d; - - fp *= 10; - /* Use modf here, not floor and subtract, so that - * the separation is done in one step. At the end - * of the loop don't break the number into parts so - * that the final digit is rounded. - */ - if (cdigits+czero+1 < precision+clead) - fp = modf(fp, &d); - - else - { - d = floor(fp + .5); - - if (d > 9) - { - /* Rounding up to 10, handle that here. */ - if (czero > 0) - { - --czero, d = 1; - if (cdigits == 0) --clead; - } - else - { - while (cdigits > 0 && d > 9) - { - int ch = *--ascii; - - if (exp_b10 != (-1)) - ++exp_b10; - - else if (ch == 46) - { - ch = *--ascii, ++size; - /* Advance exp_b10 to '1', so that the - * decimal point happens after the - * previous digit. - */ - exp_b10 = 1; - } - - --cdigits; - d = ch - 47; /* I.e. 1+(ch-48) */ - } - - /* Did we reach the beginning? If so adjust the - * exponent but take into account the leading - * decimal point. - */ - if (d > 9) /* cdigits == 0 */ - { - if (exp_b10 == (-1)) - { - /* Leading decimal point (plus zeros?), if - * we lose the decimal point here it must - * be reentered below. - */ - int ch = *--ascii; - - if (ch == 46) - ++size, exp_b10 = 1; - - /* Else lost a leading zero, so 'exp_b10' is - * still ok at (-1) - */ - } - else - ++exp_b10; - - /* In all cases we output a '1' */ - d = 1; - } - } - } - fp = 0; /* Guarantees termination below. */ - } - - if (d == 0) - { - ++czero; - if (cdigits == 0) ++clead; - } - else - { - /* Included embedded zeros in the digit count. */ - cdigits += czero - clead; - clead = 0; - - while (czero > 0) - { - /* exp_b10 == (-1) means we just output the decimal - * place - after the DP don't adjust 'exp_b10' any - * more! - */ - if (exp_b10 != (-1)) - { - if (exp_b10 == 0) *ascii++ = 46, --size; - /* PLUS 1: TOTAL 4 */ - --exp_b10; - } - *ascii++ = 48, --czero; - } - - if (exp_b10 != (-1)) - { - if (exp_b10 == 0) - *ascii++ = 46, --size; /* counted above */ - - --exp_b10; - } - *ascii++ = (char)(48 + (int)d), ++cdigits; - } - } - while (cdigits+czero < precision+clead && fp > DBL_MIN); - - /* The total output count (max) is now 4+precision */ - - /* Check for an exponent, if we don't need one we are - * done and just need to terminate the string. At - * this point exp_b10==(-1) is effectively if flag - it got - * to '-1' because of the decrement after outputting - * the decimal point above (the exponent required is - * *not* -1!) - */ - if (exp_b10 >= (-1) && exp_b10 <= 2) - { - /* The following only happens if we didn't output the - * leading zeros above for negative exponent, so this - * doesn't add to the digit requirement. Note that the - * two zeros here can only be output if the two leading - * zeros were *not* output, so this doesn't increase - * the output count. - */ - while (--exp_b10 >= 0) *ascii++ = 48; - - *ascii = 0; - - /* Total buffer requirement (including the '\0') is - * 5+precision - see check at the start. - */ - return; - } - - /* Here if an exponent is required, adjust size for - * the digits we output but did not count. The total - * digit output here so far is at most 1+precision - no - * decimal point and no leading or trailing zeros have - * been output. - */ - size -= cdigits; - - *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision */ - - /* The following use of an unsigned temporary avoids ambiguities in - * the signed arithmetic on exp_b10 and permits GCC at least to do - * better optimization. - */ - { - unsigned int uexp_b10; - - if (exp_b10 < 0) - { - *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */ - uexp_b10 = -exp_b10; - } - - else - uexp_b10 = exp_b10; - - cdigits = 0; - - while (uexp_b10 > 0) - { - exponent[cdigits++] = (char)(48 + uexp_b10 % 10); - uexp_b10 /= 10; - } - } - - /* Need another size check here for the exponent digits, so - * this need not be considered above. - */ - if (size > cdigits) - { - while (cdigits > 0) *ascii++ = exponent[--cdigits]; - - *ascii = 0; - - return; - } - } - } - else if (!(fp >= DBL_MIN)) - { - *ascii++ = 48; /* '0' */ - *ascii = 0; - return; - } - else - { - *ascii++ = 105; /* 'i' */ - *ascii++ = 110; /* 'n' */ - *ascii++ = 102; /* 'f' */ - *ascii = 0; - return; - } - } - - /* Here on buffer too small. */ - png_error(png_ptr, "ASCII conversion buffer too small"); -} - -# endif /* FLOATING_POINT */ - -# ifdef PNG_FIXED_POINT_SUPPORTED -/* Function to format a fixed point value in ASCII. - */ -void /* PRIVATE */ -png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii, - png_size_t size, png_fixed_point fp) -{ - /* Require space for 10 decimal digits, a decimal point, a minus sign and a - * trailing \0, 13 characters: - */ - if (size > 12) - { - png_uint_32 num; - - /* Avoid overflow here on the minimum integer. */ - if (fp < 0) - *ascii++ = 45, num = -fp; - else - num = fp; - - if (num <= 0x80000000) /* else overflowed */ - { - unsigned int ndigits = 0, first = 16 /* flag value */; - char digits[10]; - - while (num) - { - /* Split the low digit off num: */ - unsigned int tmp = num/10; - num -= tmp*10; - digits[ndigits++] = (char)(48 + num); - /* Record the first non-zero digit, note that this is a number - * starting at 1, it's not actually the array index. - */ - if (first == 16 && num > 0) - first = ndigits; - num = tmp; - } - - if (ndigits > 0) - { - while (ndigits > 5) *ascii++ = digits[--ndigits]; - /* The remaining digits are fractional digits, ndigits is '5' or - * smaller at this point. It is certainly not zero. Check for a - * non-zero fractional digit: - */ - if (first <= 5) - { - unsigned int i; - *ascii++ = 46; /* decimal point */ - /* ndigits may be <5 for small numbers, output leading zeros - * then ndigits digits to first: - */ - i = 5; - while (ndigits < i) *ascii++ = 48, --i; - while (ndigits >= first) *ascii++ = digits[--ndigits]; - /* Don't output the trailing zeros! */ - } - } - else - *ascii++ = 48; - - /* And null terminate the string: */ - *ascii = 0; - return; - } - } - - /* Here on buffer too small. */ - png_error(png_ptr, "ASCII conversion buffer too small"); -} -# endif /* FIXED_POINT */ -#endif /* SCAL */ - -#if defined(PNG_FLOATING_POINT_SUPPORTED) && \ - !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \ - (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \ - defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \ - defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \ - (defined(PNG_sCAL_SUPPORTED) && \ - defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)) -png_fixed_point -png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text) -{ - double r = floor(100000 * fp + .5); - - if (r > 2147483647. || r < -2147483648.) - png_fixed_error(png_ptr, text); - -# ifndef PNG_ERROR_TEXT_SUPPORTED - PNG_UNUSED(text) -# endif - - return (png_fixed_point)r; -} -#endif - -#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_COLORSPACE_SUPPORTED) ||\ - defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED) -/* muldiv functions */ -/* This API takes signed arguments and rounds the result to the nearest - * integer (or, for a fixed point number - the standard argument - to - * the nearest .00001). Overflow and divide by zero are signalled in - * the result, a boolean - true on success, false on overflow. - */ -int -png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times, - png_int_32 divisor) -{ - /* Return a * times / divisor, rounded. */ - if (divisor != 0) - { - if (a == 0 || times == 0) - { - *res = 0; - return 1; - } - else - { -#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - double r = a; - r *= times; - r /= divisor; - r = floor(r+.5); - - /* A png_fixed_point is a 32-bit integer. */ - if (r <= 2147483647. && r >= -2147483648.) - { - *res = (png_fixed_point)r; - return 1; - } -#else - int negative = 0; - png_uint_32 A, T, D; - png_uint_32 s16, s32, s00; - - if (a < 0) - negative = 1, A = -a; - else - A = a; - - if (times < 0) - negative = !negative, T = -times; - else - T = times; - - if (divisor < 0) - negative = !negative, D = -divisor; - else - D = divisor; - - /* Following can't overflow because the arguments only - * have 31 bits each, however the result may be 32 bits. - */ - s16 = (A >> 16) * (T & 0xffff) + - (A & 0xffff) * (T >> 16); - /* Can't overflow because the a*times bit is only 30 - * bits at most. - */ - s32 = (A >> 16) * (T >> 16) + (s16 >> 16); - s00 = (A & 0xffff) * (T & 0xffff); - - s16 = (s16 & 0xffff) << 16; - s00 += s16; - - if (s00 < s16) - ++s32; /* carry */ - - if (s32 < D) /* else overflow */ - { - /* s32.s00 is now the 64-bit product, do a standard - * division, we know that s32 < D, so the maximum - * required shift is 31. - */ - int bitshift = 32; - png_fixed_point result = 0; /* NOTE: signed */ - - while (--bitshift >= 0) - { - png_uint_32 d32, d00; - - if (bitshift > 0) - d32 = D >> (32-bitshift), d00 = D << bitshift; - - else - d32 = 0, d00 = D; - - if (s32 > d32) - { - if (s00 < d00) --s32; /* carry */ - s32 -= d32, s00 -= d00, result += 1<<bitshift; - } - - else - if (s32 == d32 && s00 >= d00) - s32 = 0, s00 -= d00, result += 1<<bitshift; - } - - /* Handle the rounding. */ - if (s00 >= (D >> 1)) - ++result; - - if (negative != 0) - result = -result; - - /* Check for overflow. */ - if ((negative != 0 && result <= 0) || - (negative == 0 && result >= 0)) - { - *res = result; - return 1; - } - } -#endif - } - } - - return 0; -} -#endif /* READ_GAMMA || INCH_CONVERSIONS */ - -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) -/* The following is for when the caller doesn't much care about the - * result. - */ -png_fixed_point -png_muldiv_warn(png_const_structrp png_ptr, png_fixed_point a, png_int_32 times, - png_int_32 divisor) -{ - png_fixed_point result; - - if (png_muldiv(&result, a, times, divisor) != 0) - return result; - - png_warning(png_ptr, "fixed point overflow ignored"); - return 0; -} -#endif - -#ifdef PNG_GAMMA_SUPPORTED /* more fixed point functions for gamma */ -/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */ -png_fixed_point -png_reciprocal(png_fixed_point a) -{ -#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - double r = floor(1E10/a+.5); - - if (r <= 2147483647. && r >= -2147483648.) - return (png_fixed_point)r; -#else - png_fixed_point res; - - if (png_muldiv(&res, 100000, 100000, a) != 0) - return res; -#endif - - return 0; /* error/overflow */ -} - -/* This is the shared test on whether a gamma value is 'significant' - whether - * it is worth doing gamma correction. - */ -int /* PRIVATE */ -png_gamma_significant(png_fixed_point gamma_val) -{ - return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED || - gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED; -} -#endif - -#ifdef PNG_READ_GAMMA_SUPPORTED -#ifdef PNG_16BIT_SUPPORTED -/* A local convenience routine. */ -static png_fixed_point -png_product2(png_fixed_point a, png_fixed_point b) -{ - /* The required result is 1/a * 1/b; the following preserves accuracy. */ -#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - double r = a * 1E-5; - r *= b; - r = floor(r+.5); - - if (r <= 2147483647. && r >= -2147483648.) - return (png_fixed_point)r; -#else - png_fixed_point res; - - if (png_muldiv(&res, a, b, 100000) != 0) - return res; -#endif - - return 0; /* overflow */ -} -#endif /* 16BIT */ - -/* The inverse of the above. */ -png_fixed_point -png_reciprocal2(png_fixed_point a, png_fixed_point b) -{ - /* The required result is 1/a * 1/b; the following preserves accuracy. */ -#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - if (a != 0 && b != 0) - { - double r = 1E15/a; - r /= b; - r = floor(r+.5); - - if (r <= 2147483647. && r >= -2147483648.) - return (png_fixed_point)r; - } -#else - /* This may overflow because the range of png_fixed_point isn't symmetric, - * but this API is only used for the product of file and screen gamma so it - * doesn't matter that the smallest number it can produce is 1/21474, not - * 1/100000 - */ - png_fixed_point res = png_product2(a, b); - - if (res != 0) - return png_reciprocal(res); -#endif - - return 0; /* overflow */ -} -#endif /* READ_GAMMA */ - -#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */ -#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED -/* Fixed point gamma. - * - * The code to calculate the tables used below can be found in the shell script - * contrib/tools/intgamma.sh - * - * To calculate gamma this code implements fast log() and exp() calls using only - * fixed point arithmetic. This code has sufficient precision for either 8-bit - * or 16-bit sample values. - * - * The tables used here were calculated using simple 'bc' programs, but C double - * precision floating point arithmetic would work fine. - * - * 8-bit log table - * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to - * 255, so it's the base 2 logarithm of a normalized 8-bit floating point - * mantissa. The numbers are 32-bit fractions. - */ -static const png_uint_32 -png_8bit_l2[128] = -{ - 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U, - 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U, - 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U, - 3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U, - 3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U, - 2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U, - 2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U, - 2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U, - 2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U, - 2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U, - 1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U, - 1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U, - 1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U, - 1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U, - 1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U, - 971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U, - 803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U, - 639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U, - 479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U, - 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U, - 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U, - 24347096U, 0U - -#if 0 - /* The following are the values for 16-bit tables - these work fine for the - * 8-bit conversions but produce very slightly larger errors in the 16-bit - * log (about 1.2 as opposed to 0.7 absolute error in the final value). To - * use these all the shifts below must be adjusted appropriately. - */ - 65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054, - 57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803, - 50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068, - 43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782, - 37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887, - 31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339, - 25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098, - 20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132, - 15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415, - 10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523, - 6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495, - 1119, 744, 372 -#endif -}; - -static png_int_32 -png_log8bit(unsigned int x) -{ - unsigned int lg2 = 0; - /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log, - * because the log is actually negate that means adding 1. The final - * returned value thus has the range 0 (for 255 input) to 7.994 (for 1 - * input), return -1 for the overflow (log 0) case, - so the result is - * always at most 19 bits. - */ - if ((x &= 0xff) == 0) - return -1; - - if ((x & 0xf0) == 0) - lg2 = 4, x <<= 4; - - if ((x & 0xc0) == 0) - lg2 += 2, x <<= 2; - - if ((x & 0x80) == 0) - lg2 += 1, x <<= 1; - - /* result is at most 19 bits, so this cast is safe: */ - return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16)); -} - -/* The above gives exact (to 16 binary places) log2 values for 8-bit images, - * for 16-bit images we use the most significant 8 bits of the 16-bit value to - * get an approximation then multiply the approximation by a correction factor - * determined by the remaining up to 8 bits. This requires an additional step - * in the 16-bit case. - * - * We want log2(value/65535), we have log2(v'/255), where: - * - * value = v' * 256 + v'' - * = v' * f - * - * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128 - * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less - * than 258. The final factor also needs to correct for the fact that our 8-bit - * value is scaled by 255, whereas the 16-bit values must be scaled by 65535. - * - * This gives a final formula using a calculated value 'x' which is value/v' and - * scaling by 65536 to match the above table: - * - * log2(x/257) * 65536 - * - * Since these numbers are so close to '1' we can use simple linear - * interpolation between the two end values 256/257 (result -368.61) and 258/257 - * (result 367.179). The values used below are scaled by a further 64 to give - * 16-bit precision in the interpolation: - * - * Start (256): -23591 - * Zero (257): 0 - * End (258): 23499 - */ -#ifdef PNG_16BIT_SUPPORTED -static png_int_32 -png_log16bit(png_uint_32 x) -{ - unsigned int lg2 = 0; - - /* As above, but now the input has 16 bits. */ - if ((x &= 0xffff) == 0) - return -1; - - if ((x & 0xff00) == 0) - lg2 = 8, x <<= 8; - - if ((x & 0xf000) == 0) - lg2 += 4, x <<= 4; - - if ((x & 0xc000) == 0) - lg2 += 2, x <<= 2; - - if ((x & 0x8000) == 0) - lg2 += 1, x <<= 1; - - /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional - * value. - */ - lg2 <<= 28; - lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4; - - /* Now we need to interpolate the factor, this requires a division by the top - * 8 bits. Do this with maximum precision. - */ - x = ((x << 16) + (x >> 9)) / (x >> 8); - - /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24, - * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly - * 16 bits to interpolate to get the low bits of the result. Round the - * answer. Note that the end point values are scaled by 64 to retain overall - * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust - * the overall scaling by 6-12. Round at every step. - */ - x -= 1U << 24; - - if (x <= 65536U) /* <= '257' */ - lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12); - - else - lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12); - - /* Safe, because the result can't have more than 20 bits: */ - return (png_int_32)((lg2 + 2048) >> 12); -} -#endif /* 16BIT */ - -/* The 'exp()' case must invert the above, taking a 20-bit fixed point - * logarithmic value and returning a 16 or 8-bit number as appropriate. In - * each case only the low 16 bits are relevant - the fraction - since the - * integer bits (the top 4) simply determine a shift. - * - * The worst case is the 16-bit distinction between 65535 and 65534. This - * requires perhaps spurious accuracy in the decoding of the logarithm to - * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance - * of getting this accuracy in practice. - * - * To deal with this the following exp() function works out the exponent of the - * frational part of the logarithm by using an accurate 32-bit value from the - * top four fractional bits then multiplying in the remaining bits. - */ -static const png_uint_32 -png_32bit_exp[16] = -{ - /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */ - 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U, - 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U, - 2553802834U, 2445529972U, 2341847524U, 2242560872U -}; - -/* Adjustment table; provided to explain the numbers in the code below. */ -#if 0 -for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"} - 11 44937.64284865548751208448 - 10 45180.98734845585101160448 - 9 45303.31936980687359311872 - 8 45364.65110595323018870784 - 7 45395.35850361789624614912 - 6 45410.72259715102037508096 - 5 45418.40724413220722311168 - 4 45422.25021786898173001728 - 3 45424.17186732298419044352 - 2 45425.13273269940811464704 - 1 45425.61317555035558641664 - 0 45425.85339951654943850496 -#endif - -static png_uint_32 -png_exp(png_fixed_point x) -{ - if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */ - { - /* Obtain a 4-bit approximation */ - png_uint_32 e = png_32bit_exp[(x >> 12) & 0x0f]; - - /* Incorporate the low 12 bits - these decrease the returned value by - * multiplying by a number less than 1 if the bit is set. The multiplier - * is determined by the above table and the shift. Notice that the values - * converge on 45426 and this is used to allow linear interpolation of the - * low bits. - */ - if (x & 0x800) - e -= (((e >> 16) * 44938U) + 16U) >> 5; - - if (x & 0x400) - e -= (((e >> 16) * 45181U) + 32U) >> 6; - - if (x & 0x200) - e -= (((e >> 16) * 45303U) + 64U) >> 7; - - if (x & 0x100) - e -= (((e >> 16) * 45365U) + 128U) >> 8; - - if (x & 0x080) - e -= (((e >> 16) * 45395U) + 256U) >> 9; - - if (x & 0x040) - e -= (((e >> 16) * 45410U) + 512U) >> 10; - - /* And handle the low 6 bits in a single block. */ - e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9; - - /* Handle the upper bits of x. */ - e >>= x >> 16; - return e; - } - - /* Check for overflow */ - if (x <= 0) - return png_32bit_exp[0]; - - /* Else underflow */ - return 0; -} - -static png_byte -png_exp8bit(png_fixed_point lg2) -{ - /* Get a 32-bit value: */ - png_uint_32 x = png_exp(lg2); - - /* Convert the 32-bit value to 0..255 by multiplying by 256-1. Note that the - * second, rounding, step can't overflow because of the first, subtraction, - * step. - */ - x -= x >> 8; - return (png_byte)(((x + 0x7fffffU) >> 24) & 0xff); -} - -#ifdef PNG_16BIT_SUPPORTED -static png_uint_16 -png_exp16bit(png_fixed_point lg2) -{ - /* Get a 32-bit value: */ - png_uint_32 x = png_exp(lg2); - - /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */ - x -= x >> 16; - return (png_uint_16)((x + 32767U) >> 16); -} -#endif /* 16BIT */ -#endif /* FLOATING_ARITHMETIC */ - -png_byte -png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val) -{ - if (value > 0 && value < 255) - { -# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - /* 'value' is unsigned, ANSI-C90 requires the compiler to correctly - * convert this to a floating point value. This includes values that - * would overflow if 'value' were to be converted to 'int'. - * - * Apparently GCC, however, does an intermediate conversion to (int) - * on some (ARM) but not all (x86) platforms, possibly because of - * hardware FP limitations. (E.g. if the hardware conversion always - * assumes the integer register contains a signed value.) This results - * in ANSI-C undefined behavior for large values. - * - * Other implementations on the same machine might actually be ANSI-C90 - * conformant and therefore compile spurious extra code for the large - * values. - * - * We can be reasonably sure that an unsigned to float conversion - * won't be faster than an int to float one. Therefore this code - * assumes responsibility for the undefined behavior, which it knows - * can't happen because of the check above. - * - * Note the argument to this routine is an (unsigned int) because, on - * 16-bit platforms, it is assigned a value which might be out of - * range for an (int); that would result in undefined behavior in the - * caller if the *argument* ('value') were to be declared (int). - */ - double r = floor(255*pow((int)/*SAFE*/value/255.,gamma_val*.00001)+.5); - return (png_byte)r; -# else - png_int_32 lg2 = png_log8bit(value); - png_fixed_point res; - - if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0) - return png_exp8bit(res); - - /* Overflow. */ - value = 0; -# endif - } - - return (png_byte)(value & 0xff); -} - -#ifdef PNG_16BIT_SUPPORTED -png_uint_16 -png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val) -{ - if (value > 0 && value < 65535) - { -# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - /* The same (unsigned int)->(double) constraints apply here as above, - * however in this case the (unsigned int) to (int) conversion can - * overflow on an ANSI-C90 compliant system so the cast needs to ensure - * that this is not possible. - */ - double r = floor(65535*pow((png_int_32)value/65535., - gamma_val*.00001)+.5); - return (png_uint_16)r; -# else - png_int_32 lg2 = png_log16bit(value); - png_fixed_point res; - - if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0) - return png_exp16bit(res); - - /* Overflow. */ - value = 0; -# endif - } - - return (png_uint_16)value; -} -#endif /* 16BIT */ - -/* This does the right thing based on the bit_depth field of the - * png_struct, interpreting values as 8-bit or 16-bit. While the result - * is nominally a 16-bit value if bit depth is 8 then the result is - * 8-bit (as are the arguments.) - */ -png_uint_16 /* PRIVATE */ -png_gamma_correct(png_structrp png_ptr, unsigned int value, - png_fixed_point gamma_val) -{ - if (png_ptr->bit_depth == 8) - return png_gamma_8bit_correct(value, gamma_val); - -#ifdef PNG_16BIT_SUPPORTED - else - return png_gamma_16bit_correct(value, gamma_val); -#else - /* should not reach this */ - return 0; -#endif /* 16BIT */ -} - -#ifdef PNG_16BIT_SUPPORTED -/* Internal function to build a single 16-bit table - the table consists of - * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount - * to shift the input values right (or 16-number_of_signifiant_bits). - * - * The caller is responsible for ensuring that the table gets cleaned up on - * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument - * should be somewhere that will be cleaned. - */ -static void -png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable, - PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) -{ - /* Various values derived from 'shift': */ - PNG_CONST unsigned int num = 1U << (8U - shift); -#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - /* CSE the division and work round wacky GCC warnings (see the comments - * in png_gamma_8bit_correct for where these come from.) - */ - PNG_CONST double fmax = 1./(((png_int_32)1 << (16U - shift))-1); -#endif - PNG_CONST unsigned int max = (1U << (16U - shift))-1U; - PNG_CONST unsigned int max_by_2 = 1U << (15U-shift); - unsigned int i; - - png_uint_16pp table = *ptable = - (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p))); - - for (i = 0; i < num; i++) - { - png_uint_16p sub_table = table[i] = - (png_uint_16p)png_malloc(png_ptr, 256 * (sizeof (png_uint_16))); - - /* The 'threshold' test is repeated here because it can arise for one of - * the 16-bit tables even if the others don't hit it. - */ - if (png_gamma_significant(gamma_val) != 0) - { - /* The old code would overflow at the end and this would cause the - * 'pow' function to return a result >1, resulting in an - * arithmetic error. This code follows the spec exactly; ig is - * the recovered input sample, it always has 8-16 bits. - * - * We want input * 65535/max, rounded, the arithmetic fits in 32 - * bits (unsigned) so long as max <= 32767. - */ - unsigned int j; - for (j = 0; j < 256; j++) - { - png_uint_32 ig = (j << (8-shift)) + i; -# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED - /* Inline the 'max' scaling operation: */ - /* See png_gamma_8bit_correct for why the cast to (int) is - * required here. - */ - double d = floor(65535.*pow(ig*fmax, gamma_val*.00001)+.5); - sub_table[j] = (png_uint_16)d; -# else - if (shift != 0) - ig = (ig * 65535U + max_by_2)/max; - - sub_table[j] = png_gamma_16bit_correct(ig, gamma_val); -# endif - } - } - else - { - /* We must still build a table, but do it the fast way. */ - unsigned int j; - - for (j = 0; j < 256; j++) - { - png_uint_32 ig = (j << (8-shift)) + i; - - if (shift != 0) - ig = (ig * 65535U + max_by_2)/max; - - sub_table[j] = (png_uint_16)ig; - } - } - } -} - -/* NOTE: this function expects the *inverse* of the overall gamma transformation - * required. - */ -static void -png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable, - PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) -{ - PNG_CONST unsigned int num = 1U << (8U - shift); - PNG_CONST unsigned int max = (1U << (16U - shift))-1U; - unsigned int i; - png_uint_32 last; - - png_uint_16pp table = *ptable = - (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p))); - - /* 'num' is the number of tables and also the number of low bits of low - * bits of the input 16-bit value used to select a table. Each table is - * itself indexed by the high 8 bits of the value. - */ - for (i = 0; i < num; i++) - table[i] = (png_uint_16p)png_malloc(png_ptr, - 256 * (sizeof (png_uint_16))); - - /* 'gamma_val' is set to the reciprocal of the value calculated above, so - * pow(out,g) is an *input* value. 'last' is the last input value set. - * - * In the loop 'i' is used to find output values. Since the output is - * 8-bit there are only 256 possible values. The tables are set up to - * select the closest possible output value for each input by finding - * the input value at the boundary between each pair of output values - * and filling the table up to that boundary with the lower output - * value. - * - * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9-bit - * values the code below uses a 16-bit value in i; the values start at - * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last - * entries are filled with 255). Start i at 128 and fill all 'last' - * table entries <= 'max' - */ - last = 0; - for (i = 0; i < 255; ++i) /* 8-bit output value */ - { - /* Find the corresponding maximum input value */ - png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */ - - /* Find the boundary value in 16 bits: */ - png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val); - - /* Adjust (round) to (16-shift) bits: */ - bound = (bound * max + 32768U)/65535U + 1U; - - while (last < bound) - { - table[last & (0xffU >> shift)][last >> (8U - shift)] = out; - last++; - } - } - - /* And fill in the final entries. */ - while (last < (num << 8)) - { - table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U; - last++; - } -} -#endif /* 16BIT */ - -/* Build a single 8-bit table: same as the 16-bit case but much simpler (and - * typically much faster). Note that libpng currently does no sBIT processing - * (apparently contrary to the spec) so a 256-entry table is always generated. - */ -static void -png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable, - PNG_CONST png_fixed_point gamma_val) -{ - unsigned int i; - png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256); - - if (png_gamma_significant(gamma_val) != 0) - for (i=0; i<256; i++) - table[i] = png_gamma_8bit_correct(i, gamma_val); - - else - for (i=0; i<256; ++i) - table[i] = (png_byte)(i & 0xff); -} - -/* Used from png_read_destroy and below to release the memory used by the gamma - * tables. - */ -void /* PRIVATE */ -png_destroy_gamma_table(png_structrp png_ptr) -{ - png_free(png_ptr, png_ptr->gamma_table); - png_ptr->gamma_table = NULL; - -#ifdef PNG_16BIT_SUPPORTED - if (png_ptr->gamma_16_table != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_table[i]); - } - png_free(png_ptr, png_ptr->gamma_16_table); - png_ptr->gamma_16_table = NULL; - } -#endif /* 16BIT */ - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ - defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - png_free(png_ptr, png_ptr->gamma_from_1); - png_ptr->gamma_from_1 = NULL; - png_free(png_ptr, png_ptr->gamma_to_1); - png_ptr->gamma_to_1 = NULL; - -#ifdef PNG_16BIT_SUPPORTED - if (png_ptr->gamma_16_from_1 != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_from_1[i]); - } - png_free(png_ptr, png_ptr->gamma_16_from_1); - png_ptr->gamma_16_from_1 = NULL; - } - if (png_ptr->gamma_16_to_1 != NULL) - { - int i; - int istop = (1 << (8 - png_ptr->gamma_shift)); - for (i = 0; i < istop; i++) - { - png_free(png_ptr, png_ptr->gamma_16_to_1[i]); - } - png_free(png_ptr, png_ptr->gamma_16_to_1); - png_ptr->gamma_16_to_1 = NULL; - } -#endif /* 16BIT */ -#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ -} - -/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit - * tables, we don't make a full table if we are reducing to 8-bit in - * the future. Note also how the gamma_16 tables are segmented so that - * we don't need to allocate > 64K chunks for a full 16-bit table. - */ -void /* PRIVATE */ -png_build_gamma_table(png_structrp png_ptr, int bit_depth) -{ - png_debug(1, "in png_build_gamma_table"); - - /* Remove any existing table; this copes with multiple calls to - * png_read_update_info. The warning is because building the gamma tables - * multiple times is a performance hit - it's harmless but the ability to call - * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible - * to warn if the app introduces such a hit. - */ - if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL) - { - png_warning(png_ptr, "gamma table being rebuilt"); - png_destroy_gamma_table(png_ptr); - } - - if (bit_depth <= 8) - { - png_build_8bit_table(png_ptr, &png_ptr->gamma_table, - png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ - defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) - { - png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, - png_reciprocal(png_ptr->colorspace.gamma)); - - png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1, - png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : - png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); - } -#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ - } -#ifdef PNG_16BIT_SUPPORTED - else - { - png_byte shift, sig_bit; - - if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) - { - sig_bit = png_ptr->sig_bit.red; - - if (png_ptr->sig_bit.green > sig_bit) - sig_bit = png_ptr->sig_bit.green; - - if (png_ptr->sig_bit.blue > sig_bit) - sig_bit = png_ptr->sig_bit.blue; - } - else - sig_bit = png_ptr->sig_bit.gray; - - /* 16-bit gamma code uses this equation: - * - * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8] - * - * Where 'iv' is the input color value and 'ov' is the output value - - * pow(iv, gamma). - * - * Thus the gamma table consists of up to 256 256-entry tables. The table - * is selected by the (8-gamma_shift) most significant of the low 8 bits of - * the color value then indexed by the upper 8 bits: - * - * table[low bits][high 8 bits] - * - * So the table 'n' corresponds to all those 'iv' of: - * - * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1> - * - */ - if (sig_bit > 0 && sig_bit < 16U) - /* shift == insignificant bits */ - shift = (png_byte)((16U - sig_bit) & 0xff); - - else - shift = 0; /* keep all 16 bits */ - - if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) - { - /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively - * the significant bits in the *input* when the output will - * eventually be 8 bits. By default it is 11. - */ - if (shift < (16U - PNG_MAX_GAMMA_8)) - shift = (16U - PNG_MAX_GAMMA_8); - } - - if (shift > 8U) - shift = 8U; /* Guarantees at least one table! */ - - png_ptr->gamma_shift = shift; - - /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now - * PNG_COMPOSE). This effectively smashed the background calculation for - * 16-bit output because the 8-bit table assumes the result will be reduced - * to 8 bits. - */ - if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) - png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift, - png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); - - else - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift, - png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma) : PNG_FP_1); - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ - defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) - { - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift, - png_reciprocal(png_ptr->colorspace.gamma)); - - /* Notice that the '16 from 1' table should be full precision, however - * the lookup on this table still uses gamma_shift, so it can't be. - * TODO: fix this. - */ - png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift, - png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : - png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); - } -#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ - } -#endif /* 16BIT */ -} -#endif /* READ_GAMMA */ - -/* HARDWARE OR SOFTWARE OPTION SUPPORT */ -#ifdef PNG_SET_OPTION_SUPPORTED -int PNGAPI -png_set_option(png_structrp png_ptr, int option, int onoff) -{ - if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT && - (option & 1) == 0) - { - int mask = 3 << option; - int setting = (2 + (onoff != 0)) << option; - int current = png_ptr->options; - - png_ptr->options = (png_byte)(((current & ~mask) | setting) & 0xff); - - return (current & mask) >> option; - } - - return PNG_OPTION_INVALID; -} -#endif - -/* sRGB support */ -#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ - defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) -/* sRGB conversion tables; these are machine generated with the code in - * contrib/tools/makesRGB.c. The actual sRGB transfer curve defined in the - * specification (see the article at http://en.wikipedia.org/wiki/SRGB) - * is used, not the gamma=1/2.2 approximation use elsewhere in libpng. - * The sRGB to linear table is exact (to the nearest 16-bit linear fraction). - * The inverse (linear to sRGB) table has accuracies as follows: - * - * For all possible (255*65535+1) input values: - * - * error: -0.515566 - 0.625971, 79441 (0.475369%) of readings inexact - * - * For the input values corresponding to the 65536 16-bit values: - * - * error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact - * - * In all cases the inexact readings are only off by one. - */ - -#ifdef PNG_SIMPLIFIED_READ_SUPPORTED -/* The convert-to-sRGB table is only currently required for read. */ -const png_uint_16 png_sRGB_table[256] = -{ - 0,20,40,60,80,99,119,139, - 159,179,199,219,241,264,288,313, - 340,367,396,427,458,491,526,562, - 599,637,677,718,761,805,851,898, - 947,997,1048,1101,1156,1212,1270,1330, - 1391,1453,1517,1583,1651,1720,1790,1863, - 1937,2013,2090,2170,2250,2333,2418,2504, - 2592,2681,2773,2866,2961,3058,3157,3258, - 3360,3464,3570,3678,3788,3900,4014,4129, - 4247,4366,4488,4611,4736,4864,4993,5124, - 5257,5392,5530,5669,5810,5953,6099,6246, - 6395,6547,6700,6856,7014,7174,7335,7500, - 7666,7834,8004,8177,8352,8528,8708,8889, - 9072,9258,9445,9635,9828,10022,10219,10417, - 10619,10822,11028,11235,11446,11658,11873,12090, - 12309,12530,12754,12980,13209,13440,13673,13909, - 14146,14387,14629,14874,15122,15371,15623,15878, - 16135,16394,16656,16920,17187,17456,17727,18001, - 18277,18556,18837,19121,19407,19696,19987,20281, - 20577,20876,21177,21481,21787,22096,22407,22721, - 23038,23357,23678,24002,24329,24658,24990,25325, - 25662,26001,26344,26688,27036,27386,27739,28094, - 28452,28813,29176,29542,29911,30282,30656,31033, - 31412,31794,32179,32567,32957,33350,33745,34143, - 34544,34948,35355,35764,36176,36591,37008,37429, - 37852,38278,38706,39138,39572,40009,40449,40891, - 41337,41785,42236,42690,43147,43606,44069,44534, - 45002,45473,45947,46423,46903,47385,47871,48359, - 48850,49344,49841,50341,50844,51349,51858,52369, - 52884,53401,53921,54445,54971,55500,56032,56567, - 57105,57646,58190,58737,59287,59840,60396,60955, - 61517,62082,62650,63221,63795,64372,64952,65535 -}; -#endif /* SIMPLIFIED_READ */ - -/* The base/delta tables are required for both read and write (but currently - * only the simplified versions.) - */ -const png_uint_16 png_sRGB_base[512] = -{ - 128,1782,3383,4644,5675,6564,7357,8074, - 8732,9346,9921,10463,10977,11466,11935,12384, - 12816,13233,13634,14024,14402,14769,15125,15473, - 15812,16142,16466,16781,17090,17393,17690,17981, - 18266,18546,18822,19093,19359,19621,19879,20133, - 20383,20630,20873,21113,21349,21583,21813,22041, - 22265,22487,22707,22923,23138,23350,23559,23767, - 23972,24175,24376,24575,24772,24967,25160,25352, - 25542,25730,25916,26101,26284,26465,26645,26823, - 27000,27176,27350,27523,27695,27865,28034,28201, - 28368,28533,28697,28860,29021,29182,29341,29500, - 29657,29813,29969,30123,30276,30429,30580,30730, - 30880,31028,31176,31323,31469,31614,31758,31902, - 32045,32186,32327,32468,32607,32746,32884,33021, - 33158,33294,33429,33564,33697,33831,33963,34095, - 34226,34357,34486,34616,34744,34873,35000,35127, - 35253,35379,35504,35629,35753,35876,35999,36122, - 36244,36365,36486,36606,36726,36845,36964,37083, - 37201,37318,37435,37551,37668,37783,37898,38013, - 38127,38241,38354,38467,38580,38692,38803,38915, - 39026,39136,39246,39356,39465,39574,39682,39790, - 39898,40005,40112,40219,40325,40431,40537,40642, - 40747,40851,40955,41059,41163,41266,41369,41471, - 41573,41675,41777,41878,41979,42079,42179,42279, - 42379,42478,42577,42676,42775,42873,42971,43068, - 43165,43262,43359,43456,43552,43648,43743,43839, - 43934,44028,44123,44217,44311,44405,44499,44592, - 44685,44778,44870,44962,45054,45146,45238,45329, - 45420,45511,45601,45692,45782,45872,45961,46051, - 46140,46229,46318,46406,46494,46583,46670,46758, - 46846,46933,47020,47107,47193,47280,47366,47452, - 47538,47623,47709,47794,47879,47964,48048,48133, - 48217,48301,48385,48468,48552,48635,48718,48801, - 48884,48966,49048,49131,49213,49294,49376,49458, - 49539,49620,49701,49782,49862,49943,50023,50103, - 50183,50263,50342,50422,50501,50580,50659,50738, - 50816,50895,50973,51051,51129,51207,51285,51362, - 51439,51517,51594,51671,51747,51824,51900,51977, - 52053,52129,52205,52280,52356,52432,52507,52582, - 52657,52732,52807,52881,52956,53030,53104,53178, - 53252,53326,53400,53473,53546,53620,53693,53766, - 53839,53911,53984,54056,54129,54201,54273,54345, - 54417,54489,54560,54632,54703,54774,54845,54916, - 54987,55058,55129,55199,55269,55340,55410,55480, - 55550,55620,55689,55759,55828,55898,55967,56036, - 56105,56174,56243,56311,56380,56448,56517,56585, - 56653,56721,56789,56857,56924,56992,57059,57127, - 57194,57261,57328,57395,57462,57529,57595,57662, - 57728,57795,57861,57927,57993,58059,58125,58191, - 58256,58322,58387,58453,58518,58583,58648,58713, - 58778,58843,58908,58972,59037,59101,59165,59230, - 59294,59358,59422,59486,59549,59613,59677,59740, - 59804,59867,59930,59993,60056,60119,60182,60245, - 60308,60370,60433,60495,60558,60620,60682,60744, - 60806,60868,60930,60992,61054,61115,61177,61238, - 61300,61361,61422,61483,61544,61605,61666,61727, - 61788,61848,61909,61969,62030,62090,62150,62211, - 62271,62331,62391,62450,62510,62570,62630,62689, - 62749,62808,62867,62927,62986,63045,63104,63163, - 63222,63281,63340,63398,63457,63515,63574,63632, - 63691,63749,63807,63865,63923,63981,64039,64097, - 64155,64212,64270,64328,64385,64443,64500,64557, - 64614,64672,64729,64786,64843,64900,64956,65013, - 65070,65126,65183,65239,65296,65352,65409,65465 -}; - -const png_byte png_sRGB_delta[512] = -{ - 207,201,158,129,113,100,90,82,77,72,68,64,61,59,56,54, - 52,50,49,47,46,45,43,42,41,40,39,39,38,37,36,36, - 35,34,34,33,33,32,32,31,31,30,30,30,29,29,28,28, - 28,27,27,27,27,26,26,26,25,25,25,25,24,24,24,24, - 23,23,23,23,23,22,22,22,22,22,22,21,21,21,21,21, - 21,20,20,20,20,20,20,20,20,19,19,19,19,19,19,19, - 19,18,18,18,18,18,18,18,18,18,18,17,17,17,17,17, - 17,17,17,17,17,17,16,16,16,16,16,16,16,16,16,16, - 16,16,16,16,15,15,15,15,15,15,15,15,15,15,15,15, - 15,15,15,15,14,14,14,14,14,14,14,14,14,14,14,14, - 14,14,14,14,14,14,14,13,13,13,13,13,13,13,13,13, - 13,13,13,13,13,13,13,13,13,13,13,13,13,13,12,12, - 12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12, - 12,12,12,12,12,12,12,12,12,12,12,12,11,11,11,11, - 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11, - 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11, - 11,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, - 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, - 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, - 10,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, - 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, - 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, - 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, - 9,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,7,7,7,7,7,7,7, - 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, - 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, - 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 -}; -#endif /* SIMPLIFIED READ/WRITE sRGB support */ - -/* SIMPLIFIED READ/WRITE SUPPORT */ -#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ - defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) -static int -png_image_free_function(png_voidp argument) -{ - png_imagep image = png_voidcast(png_imagep, argument); - png_controlp cp = image->opaque; - png_control c; - - /* Double check that we have a png_ptr - it should be impossible to get here - * without one. - */ - if (cp->png_ptr == NULL) - return 0; - - /* First free any data held in the control structure. */ -# ifdef PNG_STDIO_SUPPORTED - if (cp->owned_file != 0) - { - FILE *fp = png_voidcast(FILE*, cp->png_ptr->io_ptr); - cp->owned_file = 0; - - /* Ignore errors here. */ - if (fp != NULL) - { - cp->png_ptr->io_ptr = NULL; - (void)fclose(fp); - } - } -# endif - - /* Copy the control structure so that the original, allocated, version can be - * safely freed. Notice that a png_error here stops the remainder of the - * cleanup, but this is probably fine because that would indicate bad memory - * problems anyway. - */ - c = *cp; - image->opaque = &c; - png_free(c.png_ptr, cp); - - /* Then the structures, calling the correct API. */ - if (c.for_write != 0) - { -# ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED - png_destroy_write_struct(&c.png_ptr, &c.info_ptr); -# else - png_error(c.png_ptr, "simplified write not supported"); -# endif - } - else - { -# ifdef PNG_SIMPLIFIED_READ_SUPPORTED - png_destroy_read_struct(&c.png_ptr, &c.info_ptr, NULL); -# else - png_error(c.png_ptr, "simplified read not supported"); -# endif - } - - /* Success. */ - return 1; -} - -void PNGAPI -png_image_free(png_imagep image) -{ - /* Safely call the real function, but only if doing so is safe at this point - * (if not inside an error handling context). Otherwise assume - * png_safe_execute will call this API after the return. - */ - if (image != NULL && image->opaque != NULL && - image->opaque->error_buf == NULL) - { - /* Ignore errors here: */ - (void)png_safe_execute(image, png_image_free_function, image); - image->opaque = NULL; - } -} - -int /* PRIVATE */ -png_image_error(png_imagep image, png_const_charp error_message) -{ - /* Utility to log an error. */ - png_safecat(image->message, (sizeof image->message), 0, error_message); - image->warning_or_error |= PNG_IMAGE_ERROR; - png_image_free(image); - return 0; -} - -#endif /* SIMPLIFIED READ/WRITE */ -#endif /* READ || WRITE */ diff --git a/third_party/libpng/png.h b/third_party/libpng/png.h deleted file mode 100644 index 254d54a440..0000000000 --- a/third_party/libpng/png.h +++ /dev/null @@ -1,3257 +0,0 @@ - -/* png.h - header file for PNG reference library - * - * libpng version 1.6.22rc01, May 14, 2016 - * - * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license (See LICENSE, below) - * - * Authors and maintainers: - * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat - * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger - * libpng versions 0.97, January 1998, through 1.6.22rc01, May 14, 2016: - * Glenn Randers-Pehrson. - * See also "Contributing Authors", below. - */ - -/* - * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: - * - * If you modify libpng you may insert additional notices immediately following - * this sentence. - * - * This code is released under the libpng license. - * - * Some files in the "contrib" directory and some configure-generated - * files that are distributed with libpng have other copyright owners and - * are released under other open source licenses. - * - * libpng versions 1.0.7, July 1, 2000 through 1.6.22rc01, May 14, 2016 are - * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are - * derived from libpng-1.0.6, and are distributed according to the same - * disclaimer and license as libpng-1.0.6 with the following individuals - * added to the list of Contributing Authors: - * - * Simon-Pierre Cadieux - * Eric S. Raymond - * Mans Rullgard - * Cosmin Truta - * Gilles Vollant - * James Yu - * - * and with the following additions to the disclaimer: - * - * There is no warranty against interference with your enjoyment of the - * library or against infringement. There is no warranty that our - * efforts or the library will fulfill any of your particular purposes - * or needs. This library is provided with all faults, and the entire - * risk of satisfactory quality, performance, accuracy, and effort is with - * the user. - * - * Some files in the "contrib" directory have other copyright owners and - * are released under other open source licenses. - * - * - * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are - * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from - * libpng-0.96, and are distributed according to the same disclaimer and - * license as libpng-0.96, with the following individuals added to the list - * of Contributing Authors: - * - * Tom Lane - * Glenn Randers-Pehrson - * Willem van Schaik - * - * Some files in the "scripts" directory have different copyright owners - * but are also released under this license. - * - * libpng versions 0.89, June 1996, through 0.96, May 1997, are - * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, - * and are distributed according to the same disclaimer and license as - * libpng-0.88, with the following individuals added to the list of - * Contributing Authors: - * - * John Bowler - * Kevin Bracey - * Sam Bushell - * Magnus Holmgren - * Greg Roelofs - * Tom Tanner - * - * Some files in the "scripts" directory have other copyright owners - * but are released under this license. - * - * libpng versions 0.5, May 1995, through 0.88, January 1996, are - * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. - * - * For the purposes of this copyright and license, "Contributing Authors" - * is defined as the following set of individuals: - * - * Andreas Dilger - * Dave Martindale - * Guy Eric Schalnat - * Paul Schmidt - * Tim Wegner - * - * The PNG Reference Library is supplied "AS IS". The Contributing Authors - * and Group 42, Inc. disclaim all warranties, expressed or implied, - * including, without limitation, the warranties of merchantability and of - * fitness for any purpose. The Contributing Authors and Group 42, Inc. - * assume no liability for direct, indirect, incidental, special, exemplary, - * or consequential damages, which may result from the use of the PNG - * Reference Library, even if advised of the possibility of such damage. - * - * Permission is hereby granted to use, copy, modify, and distribute this - * source code, or portions hereof, for any purpose, without fee, subject - * to the following restrictions: - * - * 1. The origin of this source code must not be misrepresented. - * - * 2. Altered versions must be plainly marked as such and must not - * be misrepresented as being the original source. - * - * 3. This Copyright notice may not be removed or altered from any - * source or altered source distribution. - * - * The Contributing Authors and Group 42, Inc. specifically permit, without - * fee, and encourage the use of this source code as a component to - * supporting the PNG file format in commercial products. If you use this - * source code in a product, acknowledgment is not required but would be - * appreciated. - * - * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. - * - * TRADEMARK: - * - * The name "libpng" has not been registered by the Copyright owner - * as a trademark in any jurisdiction. However, because libpng has - * been distributed and maintained world-wide, continually since 1995, - * the Copyright owner claims "common-law trademark protection" in any - * jurisdiction where common-law trademark is recognized. - * - * OSI CERTIFICATION: - * - * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is - * a certification mark of the Open Source Initiative. OSI has not addressed - * the additional disclaimers inserted at version 1.0.7. - * - * EXPORT CONTROL: - * - * The Copyright owner believes that the Export Control Classification - * Number (ECCN) for libpng is EAR99, which means not subject to export - * controls or International Traffic in Arms Regulations (ITAR) because - * it is open source, publicly available software, that does not contain - * any encryption software. See the EAR, paragraphs 734.3(b)(3) and - * 734.7(b). - */ - -/* - * A "png_get_copyright" function is available, for convenient use in "about" - * boxes and the like: - * - * printf("%s", png_get_copyright(NULL)); - * - * Also, the PNG logo (in PNG format, of course) is supplied in the - * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). - */ - -/* - * The contributing authors would like to thank all those who helped - * with testing, bug fixes, and patience. This wouldn't have been - * possible without all of you. - * - * Thanks to Frank J. T. Wojcik for helping with the documentation. - */ - -/* Note about libpng version numbers: - * - * Due to various miscommunications, unforeseen code incompatibilities - * and occasional factors outside the authors' control, version numbering - * on the library has not always been consistent and straightforward. - * The following table summarizes matters since version 0.89c, which was - * the first widely used release: - * - * source png.h png.h shared-lib - * version string int version - * ------- ------ ----- ---------- - * 0.89c "1.0 beta 3" 0.89 89 1.0.89 - * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] - * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] - * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] - * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] - * 0.97c 0.97 97 2.0.97 - * 0.98 0.98 98 2.0.98 - * 0.99 0.99 98 2.0.99 - * 0.99a-m 0.99 99 2.0.99 - * 1.00 1.00 100 2.1.0 [100 should be 10000] - * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] - * 1.0.1 png.h string is 10001 2.1.0 - * 1.0.1a-e identical to the 10002 from here on, the shared library - * 1.0.2 source version) 10002 is 2.V where V is the source code - * 1.0.2a-b 10003 version, except as noted. - * 1.0.3 10003 - * 1.0.3a-d 10004 - * 1.0.4 10004 - * 1.0.4a-f 10005 - * 1.0.5 (+ 2 patches) 10005 - * 1.0.5a-d 10006 - * 1.0.5e-r 10100 (not source compatible) - * 1.0.5s-v 10006 (not binary compatible) - * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) - * 1.0.6d-f 10007 (still binary incompatible) - * 1.0.6g 10007 - * 1.0.6h 10007 10.6h (testing xy.z so-numbering) - * 1.0.6i 10007 10.6i - * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) - * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) - * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) - * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) - * 1.0.7 1 10007 (still compatible) - * ... - * 1.0.19 10 10019 10.so.0.19[.0] - * ... - * 1.2.56 13 10256 12.so.0.56[.0] - * ... - * 1.5.25 15 10525 15.so.15.25[.0] - * ... - * 1.6.22 16 10622 16.so.16.22[.0] - * - * Henceforth the source version will match the shared-library major - * and minor numbers; the shared-library major version number will be - * used for changes in backward compatibility, as it is intended. The - * PNG_LIBPNG_VER macro, which is not used within libpng but is available - * for applications, is an unsigned integer of the form xyyzz corresponding - * to the source version x.y.z (leading zeros in y and z). Beta versions - * were given the previous public release number plus a letter, until - * version 1.0.6j; from then on they were given the upcoming public - * release number plus "betaNN" or "rcNN". - * - * Binary incompatibility exists only when applications make direct access - * to the info_ptr or png_ptr members through png.h, and the compiled - * application is loaded with a different version of the library. - * - * DLLNUM will change each time there are forward or backward changes - * in binary compatibility (e.g., when a new feature is added). - * - * See libpng.txt or libpng.3 for more information. The PNG specification - * is available as a W3C Recommendation and as an ISO Specification, - * <http://www.w3.org/TR/2003/REC-PNG-20031110/ - */ - -/* - * Y2K compliance in libpng: - * ========================= - * - * May 14, 2016 - * - * Since the PNG Development group is an ad-hoc body, we can't make - * an official declaration. - * - * This is your unofficial assurance that libpng from version 0.71 and - * upward through 1.6.22rc01 are Y2K compliant. It is my belief that - * earlier versions were also Y2K compliant. - * - * Libpng only has two year fields. One is a 2-byte unsigned integer - * that will hold years up to 65535. The other, which is deprecated, - * holds the date in text format, and will hold years up to 9999. - * - * The integer is - * "png_uint_16 year" in png_time_struct. - * - * The string is - * "char time_buffer[29]" in png_struct. This is no longer used - * in libpng-1.6.x and will be removed from libpng-1.7.0. - * - * There are seven time-related functions: - * png.c: png_convert_to_rfc_1123_buffer() in png.c - * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and - * png_convert_to_rfc_1152() in error prior to libpng-0.98) - * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c - * png_convert_from_time_t() in pngwrite.c - * png_get_tIME() in pngget.c - * png_handle_tIME() in pngrutil.c, called in pngread.c - * png_set_tIME() in pngset.c - * png_write_tIME() in pngwutil.c, called in pngwrite.c - * - * All handle dates properly in a Y2K environment. The - * png_convert_from_time_t() function calls gmtime() to convert from system - * clock time, which returns (year - 1900), which we properly convert to - * the full 4-digit year. There is a possibility that libpng applications - * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() - * function, or that they are incorrectly passing only a 2-digit year - * instead of "year - 1900" into the png_convert_from_struct_tm() function, - * but this is not under our control. The libpng documentation has always - * stated that it works with 4-digit years, and the APIs have been - * documented as such. - * - * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned - * integer to hold the year, and can hold years as large as 65535. - * - * zlib, upon which libpng depends, is also Y2K compliant. It contains - * no date-related code. - * - * Glenn Randers-Pehrson - * libpng maintainer - * PNG Development Group - */ - -#ifndef PNG_H -#define PNG_H - -/* This is not the place to learn how to use libpng. The file libpng-manual.txt - * describes how to use libpng, and the file example.c summarizes it - * with some code on which to build. This file is useful for looking - * at the actual function definitions and structure components. If that - * file has been stripped from your copy of libpng, you can find it at - * <http://www.libpng.org/pub/png/libpng-manual.txt> - * - * If you just need to read a PNG file and don't want to read the documentation - * skip to the end of this file and read the section entitled 'simplified API'. - */ - -/* Version information for png.h - this should match the version in png.c */ -#define PNG_LIBPNG_VER_STRING "1.6.22rc01" -#define PNG_HEADER_VERSION_STRING \ - " libpng version 1.6.22rc01 - May 14, 2016\n" - -#define PNG_LIBPNG_VER_SONUM 16 -#define PNG_LIBPNG_VER_DLLNUM 16 - -/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ -#define PNG_LIBPNG_VER_MAJOR 1 -#define PNG_LIBPNG_VER_MINOR 6 -#define PNG_LIBPNG_VER_RELEASE 22 - -/* This should match the numeric part of the final component of - * PNG_LIBPNG_VER_STRING, omitting any leading zero: - */ - -#define PNG_LIBPNG_VER_BUILD 01 - -/* Release Status */ -#define PNG_LIBPNG_BUILD_ALPHA 1 -#define PNG_LIBPNG_BUILD_BETA 2 -#define PNG_LIBPNG_BUILD_RC 3 -#define PNG_LIBPNG_BUILD_STABLE 4 -#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 - -/* Release-Specific Flags */ -#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with - PNG_LIBPNG_BUILD_STABLE only */ -#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with - PNG_LIBPNG_BUILD_SPECIAL */ -#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with - PNG_LIBPNG_BUILD_PRIVATE */ - -#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_RC - -/* Careful here. At one time, Guy wanted to use 082, but that would be octal. - * We must not include leading zeros. - * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only - * version 1.0.0 was mis-numbered 100 instead of 10000). From - * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release - */ -#define PNG_LIBPNG_VER 10622 /* 1.6.22 */ - -/* Library configuration: these options cannot be changed after - * the library has been built. - */ -#ifndef PNGLCONF_H - /* If pnglibconf.h is missing, you can - * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h - */ -# include "pnglibconf.h" -#endif - -#ifndef PNG_VERSION_INFO_ONLY - /* Machine specific configuration. */ -# include "pngconf.h" -#endif - -/* - * Added at libpng-1.2.8 - * - * Ref MSDN: Private as priority over Special - * VS_FF_PRIVATEBUILD File *was not* built using standard release - * procedures. If this value is given, the StringFileInfo block must - * contain a PrivateBuild string. - * - * VS_FF_SPECIALBUILD File *was* built by the original company using - * standard release procedures but is a variation of the standard - * file of the same version number. If this value is given, the - * StringFileInfo block must contain a SpecialBuild string. - */ - -#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ -# define PNG_LIBPNG_BUILD_TYPE \ - (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) -#else -# ifdef PNG_LIBPNG_SPECIALBUILD -# define PNG_LIBPNG_BUILD_TYPE \ - (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) -# else -# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) -# endif -#endif - -#ifndef PNG_VERSION_INFO_ONLY - -/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ -#ifdef __cplusplus -extern "C" { -#endif /* __cplusplus */ - -/* Version information for C files, stored in png.c. This had better match - * the version above. - */ -#define png_libpng_ver png_get_header_ver(NULL) - -/* This file is arranged in several sections: - * - * 1. [omitted] - * 2. Any configuration options that can be specified by for the application - * code when it is built. (Build time configuration is in pnglibconf.h) - * 3. Type definitions (base types are defined in pngconf.h), structure - * definitions. - * 4. Exported library functions. - * 5. Simplified API. - * 6. Implementation options. - * - * The library source code has additional files (principally pngpriv.h) that - * allow configuration of the library. - */ - -/* Section 1: [omitted] */ - -/* Section 2: run time configuration - * See pnglibconf.h for build time configuration - * - * Run time configuration allows the application to choose between - * implementations of certain arithmetic APIs. The default is set - * at build time and recorded in pnglibconf.h, but it is safe to - * override these (and only these) settings. Note that this won't - * change what the library does, only application code, and the - * settings can (and probably should) be made on a per-file basis - * by setting the #defines before including png.h - * - * Use macros to read integers from PNG data or use the exported - * functions? - * PNG_USE_READ_MACROS: use the macros (see below) Note that - * the macros evaluate their argument multiple times. - * PNG_NO_USE_READ_MACROS: call the relevant library function. - * - * Use the alternative algorithm for compositing alpha samples that - * does not use division? - * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' - * algorithm. - * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. - * - * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is - * false? - * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error - * APIs to png_warning. - * Otherwise the calls are mapped to png_error. - */ - -/* Section 3: type definitions, including structures and compile time - * constants. - * See pngconf.h for base types that vary by machine/system - */ - -/* This triggers a compiler error in png.c, if png.c and png.h - * do not agree upon the version number. - */ -typedef char* png_libpng_version_1_6_22rc01; - -/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. - * - * png_struct is the cache of information used while reading or writing a single - * PNG file. One of these is always required, although the simplified API - * (below) hides the creation and destruction of it. - */ -typedef struct png_struct_def png_struct; -typedef const png_struct * png_const_structp; -typedef png_struct * png_structp; -typedef png_struct * * png_structpp; - -/* png_info contains information read from or to be written to a PNG file. One - * or more of these must exist while reading or creating a PNG file. The - * information is not used by libpng during read but is used to control what - * gets written when a PNG file is created. "png_get_" function calls read - * information during read and "png_set_" functions calls write information - * when creating a PNG. - * been moved into a separate header file that is not accessible to - * applications. Read libpng-manual.txt or libpng.3 for more info. - */ -typedef struct png_info_def png_info; -typedef png_info * png_infop; -typedef const png_info * png_const_infop; -typedef png_info * * png_infopp; - -/* Types with names ending 'p' are pointer types. The corresponding types with - * names ending 'rp' are identical pointer types except that the pointer is - * marked 'restrict', which means that it is the only pointer to the object - * passed to the function. Applications should not use the 'restrict' types; - * it is always valid to pass 'p' to a pointer with a function argument of the - * corresponding 'rp' type. Different compilers have different rules with - * regard to type matching in the presence of 'restrict'. For backward - * compatibility libpng callbacks never have 'restrict' in their parameters and, - * consequentially, writing portable application code is extremely difficult if - * an attempt is made to use 'restrict'. - */ -typedef png_struct * PNG_RESTRICT png_structrp; -typedef const png_struct * PNG_RESTRICT png_const_structrp; -typedef png_info * PNG_RESTRICT png_inforp; -typedef const png_info * PNG_RESTRICT png_const_inforp; - -/* Three color definitions. The order of the red, green, and blue, (and the - * exact size) is not important, although the size of the fields need to - * be png_byte or png_uint_16 (as defined below). - */ -typedef struct png_color_struct -{ - png_byte red; - png_byte green; - png_byte blue; -} png_color; -typedef png_color * png_colorp; -typedef const png_color * png_const_colorp; -typedef png_color * * png_colorpp; - -typedef struct png_color_16_struct -{ - png_byte index; /* used for palette files */ - png_uint_16 red; /* for use in red green blue files */ - png_uint_16 green; - png_uint_16 blue; - png_uint_16 gray; /* for use in grayscale files */ -} png_color_16; -typedef png_color_16 * png_color_16p; -typedef const png_color_16 * png_const_color_16p; -typedef png_color_16 * * png_color_16pp; - -typedef struct png_color_8_struct -{ - png_byte red; /* for use in red green blue files */ - png_byte green; - png_byte blue; - png_byte gray; /* for use in grayscale files */ - png_byte alpha; /* for alpha channel files */ -} png_color_8; -typedef png_color_8 * png_color_8p; -typedef const png_color_8 * png_const_color_8p; -typedef png_color_8 * * png_color_8pp; - -/* - * The following two structures are used for the in-core representation - * of sPLT chunks. - */ -typedef struct png_sPLT_entry_struct -{ - png_uint_16 red; - png_uint_16 green; - png_uint_16 blue; - png_uint_16 alpha; - png_uint_16 frequency; -} png_sPLT_entry; -typedef png_sPLT_entry * png_sPLT_entryp; -typedef const png_sPLT_entry * png_const_sPLT_entryp; -typedef png_sPLT_entry * * png_sPLT_entrypp; - -/* When the depth of the sPLT palette is 8 bits, the color and alpha samples - * occupy the LSB of their respective members, and the MSB of each member - * is zero-filled. The frequency member always occupies the full 16 bits. - */ - -typedef struct png_sPLT_struct -{ - png_charp name; /* palette name */ - png_byte depth; /* depth of palette samples */ - png_sPLT_entryp entries; /* palette entries */ - png_int_32 nentries; /* number of palette entries */ -} png_sPLT_t; -typedef png_sPLT_t * png_sPLT_tp; -typedef const png_sPLT_t * png_const_sPLT_tp; -typedef png_sPLT_t * * png_sPLT_tpp; - -#ifdef PNG_TEXT_SUPPORTED -/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, - * and whether that contents is compressed or not. The "key" field - * points to a regular zero-terminated C string. The "text" fields can be a - * regular C string, an empty string, or a NULL pointer. - * However, the structure returned by png_get_text() will always contain - * the "text" field as a regular zero-terminated C string (possibly - * empty), never a NULL pointer, so it can be safely used in printf() and - * other string-handling functions. Note that the "itxt_length", "lang", and - * "lang_key" members of the structure only exist when the library is built - * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by - * default without iTXt support. Also note that when iTXt *is* supported, - * the "lang" and "lang_key" fields contain NULL pointers when the - * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or - * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the - * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" - * which is always 0 or 1, or its "compression method" which is always 0. - */ -typedef struct png_text_struct -{ - int compression; /* compression value: - -1: tEXt, none - 0: zTXt, deflate - 1: iTXt, none - 2: iTXt, deflate */ - png_charp key; /* keyword, 1-79 character description of "text" */ - png_charp text; /* comment, may be an empty string (ie "") - or a NULL pointer */ - png_size_t text_length; /* length of the text string */ - png_size_t itxt_length; /* length of the itxt string */ - png_charp lang; /* language code, 0-79 characters - or a NULL pointer */ - png_charp lang_key; /* keyword translated UTF-8 string, 0 or more - chars or a NULL pointer */ -} png_text; -typedef png_text * png_textp; -typedef const png_text * png_const_textp; -typedef png_text * * png_textpp; -#endif - -/* Supported compression types for text in PNG files (tEXt, and zTXt). - * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ -#define PNG_TEXT_COMPRESSION_NONE_WR -3 -#define PNG_TEXT_COMPRESSION_zTXt_WR -2 -#define PNG_TEXT_COMPRESSION_NONE -1 -#define PNG_TEXT_COMPRESSION_zTXt 0 -#define PNG_ITXT_COMPRESSION_NONE 1 -#define PNG_ITXT_COMPRESSION_zTXt 2 -#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ - -/* png_time is a way to hold the time in an machine independent way. - * Two conversions are provided, both from time_t and struct tm. There - * is no portable way to convert to either of these structures, as far - * as I know. If you know of a portable way, send it to me. As a side - * note - PNG has always been Year 2000 compliant! - */ -typedef struct png_time_struct -{ - png_uint_16 year; /* full year, as in, 1995 */ - png_byte month; /* month of year, 1 - 12 */ - png_byte day; /* day of month, 1 - 31 */ - png_byte hour; /* hour of day, 0 - 23 */ - png_byte minute; /* minute of hour, 0 - 59 */ - png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ -} png_time; -typedef png_time * png_timep; -typedef const png_time * png_const_timep; -typedef png_time * * png_timepp; - -#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ - defined(PNG_USER_CHUNKS_SUPPORTED) -/* png_unknown_chunk is a structure to hold queued chunks for which there is - * no specific support. The idea is that we can use this to queue - * up private chunks for output even though the library doesn't actually - * know about their semantics. - * - * The data in the structure is set by libpng on read and used on write. - */ -typedef struct png_unknown_chunk_t -{ - png_byte name[5]; /* Textual chunk name with '\0' terminator */ - png_byte *data; /* Data, should not be modified on read! */ - png_size_t size; - - /* On write 'location' must be set using the flag values listed below. - * Notice that on read it is set by libpng however the values stored have - * more bits set than are listed below. Always treat the value as a - * bitmask. On write set only one bit - setting multiple bits may cause the - * chunk to be written in multiple places. - */ - png_byte location; /* mode of operation at read time */ -} -png_unknown_chunk; - -typedef png_unknown_chunk * png_unknown_chunkp; -typedef const png_unknown_chunk * png_const_unknown_chunkp; -typedef png_unknown_chunk * * png_unknown_chunkpp; -#endif - -/* Flag values for the unknown chunk location byte. */ -#define PNG_HAVE_IHDR 0x01 -#define PNG_HAVE_PLTE 0x02 -#define PNG_AFTER_IDAT 0x08 - -/* Maximum positive integer used in PNG is (2^31)-1 */ -#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) -#define PNG_UINT_32_MAX ((png_uint_32)(-1)) -#define PNG_SIZE_MAX ((png_size_t)(-1)) - -/* These are constants for fixed point values encoded in the - * PNG specification manner (x100000) - */ -#define PNG_FP_1 100000 -#define PNG_FP_HALF 50000 -#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) -#define PNG_FP_MIN (-PNG_FP_MAX) - -/* These describe the color_type field in png_info. */ -/* color type masks */ -#define PNG_COLOR_MASK_PALETTE 1 -#define PNG_COLOR_MASK_COLOR 2 -#define PNG_COLOR_MASK_ALPHA 4 - -/* color types. Note that not all combinations are legal */ -#define PNG_COLOR_TYPE_GRAY 0 -#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) -#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) -#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) -#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) -/* aliases */ -#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA -#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA - -/* This is for compression type. PNG 1.0-1.2 only define the single type. */ -#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ -#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE - -/* This is for filter type. PNG 1.0-1.2 only define the single type. */ -#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ -#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ -#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE - -/* These are for the interlacing type. These values should NOT be changed. */ -#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ -#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ -#define PNG_INTERLACE_LAST 2 /* Not a valid value */ - -/* These are for the oFFs chunk. These values should NOT be changed. */ -#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ -#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ -#define PNG_OFFSET_LAST 2 /* Not a valid value */ - -/* These are for the pCAL chunk. These values should NOT be changed. */ -#define PNG_EQUATION_LINEAR 0 /* Linear transformation */ -#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ -#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ -#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ -#define PNG_EQUATION_LAST 4 /* Not a valid value */ - -/* These are for the sCAL chunk. These values should NOT be changed. */ -#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ -#define PNG_SCALE_METER 1 /* meters per pixel */ -#define PNG_SCALE_RADIAN 2 /* radians per pixel */ -#define PNG_SCALE_LAST 3 /* Not a valid value */ - -/* These are for the pHYs chunk. These values should NOT be changed. */ -#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ -#define PNG_RESOLUTION_METER 1 /* pixels/meter */ -#define PNG_RESOLUTION_LAST 2 /* Not a valid value */ - -/* These are for the sRGB chunk. These values should NOT be changed. */ -#define PNG_sRGB_INTENT_PERCEPTUAL 0 -#define PNG_sRGB_INTENT_RELATIVE 1 -#define PNG_sRGB_INTENT_SATURATION 2 -#define PNG_sRGB_INTENT_ABSOLUTE 3 -#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ - -/* This is for text chunks */ -#define PNG_KEYWORD_MAX_LENGTH 79 - -/* Maximum number of entries in PLTE/sPLT/tRNS arrays */ -#define PNG_MAX_PALETTE_LENGTH 256 - -/* These determine if an ancillary chunk's data has been successfully read - * from the PNG header, or if the application has filled in the corresponding - * data in the info_struct to be written into the output file. The values - * of the PNG_INFO_<chunk> defines should NOT be changed. - */ -#define PNG_INFO_gAMA 0x0001U -#define PNG_INFO_sBIT 0x0002U -#define PNG_INFO_cHRM 0x0004U -#define PNG_INFO_PLTE 0x0008U -#define PNG_INFO_tRNS 0x0010U -#define PNG_INFO_bKGD 0x0020U -#define PNG_INFO_hIST 0x0040U -#define PNG_INFO_pHYs 0x0080U -#define PNG_INFO_oFFs 0x0100U -#define PNG_INFO_tIME 0x0200U -#define PNG_INFO_pCAL 0x0400U -#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ -#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ -#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ -#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ -#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ - -/* This is used for the transformation routines, as some of them - * change these values for the row. It also should enable using - * the routines for other purposes. - */ -typedef struct png_row_info_struct -{ - png_uint_32 width; /* width of row */ - png_size_t rowbytes; /* number of bytes in row */ - png_byte color_type; /* color type of row */ - png_byte bit_depth; /* bit depth of row */ - png_byte channels; /* number of channels (1, 2, 3, or 4) */ - png_byte pixel_depth; /* bits per pixel (depth * channels) */ -} png_row_info; - -typedef png_row_info * png_row_infop; -typedef png_row_info * * png_row_infopp; - -/* These are the function types for the I/O functions and for the functions - * that allow the user to override the default I/O functions with his or her - * own. The png_error_ptr type should match that of user-supplied warning - * and error functions, while the png_rw_ptr type should match that of the - * user read/write data functions. Note that the 'write' function must not - * modify the buffer it is passed. The 'read' function, on the other hand, is - * expected to return the read data in the buffer. - */ -typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); -typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); -typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); -typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, - int)); -typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, - int)); - -#ifdef PNG_PROGRESSIVE_READ_SUPPORTED -typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); -typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); - -/* The following callback receives png_uint_32 row_number, int pass for the - * png_bytep data of the row. When transforming an interlaced image the - * row number is the row number within the sub-image of the interlace pass, so - * the value will increase to the height of the sub-image (not the full image) - * then reset to 0 for the next pass. - * - * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to - * find the output pixel (x,y) given an interlaced sub-image pixel - * (row,col,pass). (See below for these macros.) - */ -typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, - png_uint_32, int)); -#endif - -#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ - defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) -typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, - png_bytep)); -#endif - -#ifdef PNG_USER_CHUNKS_SUPPORTED -typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, - png_unknown_chunkp)); -#endif -#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED -/* not used anywhere */ -/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ -#endif - -#ifdef PNG_SETJMP_SUPPORTED -/* This must match the function definition in <setjmp.h>, and the application - * must include this before png.h to obtain the definition of jmp_buf. The - * function is required to be PNG_NORETURN, but this is not checked. If the - * function does return the application will crash via an abort() or similar - * system level call. - * - * If you get a warning here while building the library you may need to make - * changes to ensure that pnglibconf.h records the calling convention used by - * your compiler. This may be very difficult - try using a different compiler - * to build the library! - */ -PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); -#endif - -/* Transform masks for the high-level interface */ -#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ -#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ -#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ -#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ -#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ -#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ -#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ -#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ -#define PNG_TRANSFORM_BGR 0x0080 /* read and write */ -#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ -#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ -#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ -#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ -/* Added to libpng-1.2.34 */ -#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER -#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ -/* Added to libpng-1.4.0 */ -#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ -/* Added to libpng-1.5.4 */ -#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ -#if INT_MAX >= 0x8000 /* else this might break */ -#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ -#endif - -/* Flags for MNG supported features */ -#define PNG_FLAG_MNG_EMPTY_PLTE 0x01 -#define PNG_FLAG_MNG_FILTER_64 0x04 -#define PNG_ALL_MNG_FEATURES 0x05 - -/* NOTE: prior to 1.5 these functions had no 'API' style declaration, - * this allowed the zlib default functions to be used on Windows - * platforms. In 1.5 the zlib default malloc (which just calls malloc and - * ignores the first argument) should be completely compatible with the - * following. - */ -typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, - png_alloc_size_t)); -typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); - -/* Section 4: exported functions - * Here are the function definitions most commonly used. This is not - * the place to find out how to use libpng. See libpng-manual.txt for the - * full explanation, see example.c for the summary. This just provides - * a simple one line description of the use of each function. - * - * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in - * pngconf.h and in the *.dfn files in the scripts directory. - * - * PNG_EXPORT(ordinal, type, name, (args)); - * - * ordinal: ordinal that is used while building - * *.def files. The ordinal value is only - * relevant when preprocessing png.h with - * the *.dfn files for building symbol table - * entries, and are removed by pngconf.h. - * type: return type of the function - * name: function name - * args: function arguments, with types - * - * When we wish to append attributes to a function prototype we use - * the PNG_EXPORTA() macro instead. - * - * PNG_EXPORTA(ordinal, type, name, (args), attributes); - * - * ordinal, type, name, and args: same as in PNG_EXPORT(). - * attributes: function attributes - */ - -/* Returns the version number of the library */ -PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); - -/* Tell lib we have already handled the first <num_bytes> magic bytes. - * Handling more than 8 bytes from the beginning of the file is an error. - */ -PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); - -/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a - * PNG file. Returns zero if the supplied bytes match the 8-byte PNG - * signature, and non-zero otherwise. Having num_to_check == 0 or - * start > 7 will always fail (ie return non-zero). - */ -PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, - png_size_t num_to_check)); - -/* Simple signature checking function. This is the same as calling - * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). - */ -#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) - -/* Allocate and initialize png_ptr struct for reading, and any other memory. */ -PNG_EXPORTA(4, png_structp, png_create_read_struct, - (png_const_charp user_png_ver, png_voidp error_ptr, - png_error_ptr error_fn, png_error_ptr warn_fn), - PNG_ALLOCATED); - -/* Allocate and initialize png_ptr struct for writing, and any other memory */ -PNG_EXPORTA(5, png_structp, png_create_write_struct, - (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warn_fn), - PNG_ALLOCATED); - -PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, - (png_const_structrp png_ptr)); - -PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, - png_size_t size)); - -/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp - * match up. - */ -#ifdef PNG_SETJMP_SUPPORTED -/* This function returns the jmp_buf built in to *png_ptr. It must be - * supplied with an appropriate 'longjmp' function to use on that jmp_buf - * unless the default error function is overridden in which case NULL is - * acceptable. The size of the jmp_buf is checked against the actual size - * allocated by the library - the call will return NULL on a mismatch - * indicating an ABI mismatch. - */ -PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, - png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); -# define png_jmpbuf(png_ptr) \ - (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) -#else -# define png_jmpbuf(png_ptr) \ - (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) -#endif -/* This function should be used by libpng applications in place of - * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it - * will use it; otherwise it will call PNG_ABORT(). This function was - * added in libpng-1.5.0. - */ -PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), - PNG_NORETURN); - -#ifdef PNG_READ_SUPPORTED -/* Reset the compression stream */ -PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); -#endif - -/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ -#ifdef PNG_USER_MEM_SUPPORTED -PNG_EXPORTA(11, png_structp, png_create_read_struct_2, - (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warn_fn, - png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), - PNG_ALLOCATED); -PNG_EXPORTA(12, png_structp, png_create_write_struct_2, - (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warn_fn, - png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), - PNG_ALLOCATED); -#endif - -/* Write the PNG file signature. */ -PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); - -/* Write a PNG chunk - size, type, (optional) data, CRC. */ -PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep - chunk_name, png_const_bytep data, png_size_t length)); - -/* Write the start of a PNG chunk - length and chunk name. */ -PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, - png_const_bytep chunk_name, png_uint_32 length)); - -/* Write the data of a PNG chunk started with png_write_chunk_start(). */ -PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, - png_const_bytep data, png_size_t length)); - -/* Finish a chunk started with png_write_chunk_start() (includes CRC). */ -PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); - -/* Allocate and initialize the info structure */ -PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), - PNG_ALLOCATED); - -/* DEPRECATED: this function allowed init structures to be created using the - * default allocation method (typically malloc). Use is deprecated in 1.6.0 and - * the API will be removed in the future. - */ -PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, - png_size_t png_info_struct_size), PNG_DEPRECATED); - -/* Writes all the PNG information before the image. */ -PNG_EXPORT(20, void, png_write_info_before_PLTE, - (png_structrp png_ptr, png_const_inforp info_ptr)); -PNG_EXPORT(21, void, png_write_info, - (png_structrp png_ptr, png_const_inforp info_ptr)); - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read the information before the actual image data. */ -PNG_EXPORT(22, void, png_read_info, - (png_structrp png_ptr, png_inforp info_ptr)); -#endif - -#ifdef PNG_TIME_RFC1123_SUPPORTED - /* Convert to a US string format: there is no localization support in this - * routine. The original implementation used a 29 character buffer in - * png_struct, this will be removed in future versions. - */ -#if PNG_LIBPNG_VER < 10700 -/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ -PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, - png_const_timep ptime),PNG_DEPRECATED); -#endif -PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], - png_const_timep ptime)); -#endif - -#ifdef PNG_CONVERT_tIME_SUPPORTED -/* Convert from a struct tm to png_time */ -PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, - const struct tm * ttime)); - -/* Convert from time_t to png_time. Uses gmtime() */ -PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); -#endif /* CONVERT_tIME */ - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ -PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); -PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); -PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); -PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); -#endif - -#ifdef PNG_READ_EXPAND_16_SUPPORTED -/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion - * of a tRNS chunk if present. - */ -PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); -#endif - -#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) -/* Use blue, green, red order for pixels. */ -PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); -#endif - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED -/* Expand the grayscale to 24-bit RGB if necessary. */ -PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); -#endif - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -/* Reduce RGB to grayscale. */ -#define PNG_ERROR_ACTION_NONE 1 -#define PNG_ERROR_ACTION_WARN 2 -#define PNG_ERROR_ACTION_ERROR 3 -#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ - -PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, - int error_action, double red, double green)) -PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, - int error_action, png_fixed_point red, png_fixed_point green)) - -PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp - png_ptr)); -#endif - -#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED -PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, - png_colorp palette)); -#endif - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED -/* How the alpha channel is interpreted - this affects how the color channels - * of a PNG file are returned to the calling application when an alpha channel, - * or a tRNS chunk in a palette file, is present. - * - * This has no effect on the way pixels are written into a PNG output - * datastream. The color samples in a PNG datastream are never premultiplied - * with the alpha samples. - * - * The default is to return data according to the PNG specification: the alpha - * channel is a linear measure of the contribution of the pixel to the - * corresponding composited pixel, and the color channels are unassociated - * (not premultiplied). The gamma encoded color channels must be scaled - * according to the contribution and to do this it is necessary to undo - * the encoding, scale the color values, perform the composition and reencode - * the values. This is the 'PNG' mode. - * - * The alternative is to 'associate' the alpha with the color information by - * storing color channel values that have been scaled by the alpha. - * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes - * (the latter being the two common names for associated alpha color channels). - * - * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha - * value is equal to the maximum value. - * - * The final choice is to gamma encode the alpha channel as well. This is - * broken because, in practice, no implementation that uses this choice - * correctly undoes the encoding before handling alpha composition. Use this - * choice only if other serious errors in the software or hardware you use - * mandate it; the typical serious error is for dark halos to appear around - * opaque areas of the composited PNG image because of arithmetic overflow. - * - * The API function png_set_alpha_mode specifies which of these choices to use - * with an enumerated 'mode' value and the gamma of the required output: - */ -#define PNG_ALPHA_PNG 0 /* according to the PNG standard */ -#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ -#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ -#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ -#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ -#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ - -PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, - double output_gamma)) -PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, - int mode, png_fixed_point output_gamma)) -#endif - -#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) -/* The output_gamma value is a screen gamma in libpng terminology: it expresses - * how to decode the output values, not how they are encoded. - */ -#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ -#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ -#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ -#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ -#endif - -/* The following are examples of calls to png_set_alpha_mode to achieve the - * required overall gamma correction and, where necessary, alpha - * premultiplication. - * - * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); - * This is the default libpng handling of the alpha channel - it is not - * pre-multiplied into the color components. In addition the call states - * that the output is for a sRGB system and causes all PNG files without gAMA - * chunks to be assumed to be encoded using sRGB. - * - * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); - * In this case the output is assumed to be something like an sRGB conformant - * display preceeded by a power-law lookup table of power 1.45. This is how - * early Mac systems behaved. - * - * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); - * This is the classic Jim Blinn approach and will work in academic - * environments where everything is done by the book. It has the shortcoming - * of assuming that input PNG data with no gamma information is linear - this - * is unlikely to be correct unless the PNG files where generated locally. - * Most of the time the output precision will be so low as to show - * significant banding in dark areas of the image. - * - * png_set_expand_16(pp); - * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); - * This is a somewhat more realistic Jim Blinn inspired approach. PNG files - * are assumed to have the sRGB encoding if not marked with a gamma value and - * the output is always 16 bits per component. This permits accurate scaling - * and processing of the data. If you know that your input PNG files were - * generated locally you might need to replace PNG_DEFAULT_sRGB with the - * correct value for your system. - * - * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); - * If you just need to composite the PNG image onto an existing background - * and if you control the code that does this you can use the optimization - * setting. In this case you just copy completely opaque pixels to the - * output. For pixels that are not completely transparent (you just skip - * those) you do the composition math using png_composite or png_composite_16 - * below then encode the resultant 8-bit or 16-bit values to match the output - * encoding. - * - * Other cases - * If neither the PNG nor the standard linear encoding work for you because - * of the software or hardware you use then you have a big problem. The PNG - * case will probably result in halos around the image. The linear encoding - * will probably result in a washed out, too bright, image (it's actually too - * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably - * substantially reduce the halos. Alternatively try: - * - * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); - * This option will also reduce the halos, but there will be slight dark - * halos round the opaque parts of the image where the background is light. - * In the OPTIMIZED mode the halos will be light halos where the background - * is dark. Take your pick - the halos are unavoidable unless you can get - * your hardware/software fixed! (The OPTIMIZED approach is slightly - * faster.) - * - * When the default gamma of PNG files doesn't match the output gamma. - * If you have PNG files with no gamma information png_set_alpha_mode allows - * you to provide a default gamma, but it also sets the ouput gamma to the - * matching value. If you know your PNG files have a gamma that doesn't - * match the output you can take advantage of the fact that - * png_set_alpha_mode always sets the output gamma but only sets the PNG - * default if it is not already set: - * - * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); - * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); - * The first call sets both the default and the output gamma values, the - * second call overrides the output gamma without changing the default. This - * is easier than achieving the same effect with png_set_gamma. You must use - * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will - * fire if more than one call to png_set_alpha_mode and png_set_background is - * made in the same read operation, however multiple calls with PNG_ALPHA_PNG - * are ignored. - */ - -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED -PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); -#endif - -#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ - defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) -PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); -#endif - -#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ - defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) -PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); -#endif - -#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) -/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ -PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, - int flags)); -/* The values of the PNG_FILLER_ defines should NOT be changed */ -# define PNG_FILLER_BEFORE 0 -# define PNG_FILLER_AFTER 1 -/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ -PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, - png_uint_32 filler, int flags)); -#endif /* READ_FILLER || WRITE_FILLER */ - -#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) -/* Swap bytes in 16-bit depth files. */ -PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); -#endif - -#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) -/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ -PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); -#endif - -#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ - defined(PNG_WRITE_PACKSWAP_SUPPORTED) -/* Swap packing order of pixels in bytes. */ -PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); -#endif - -#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) -/* Converts files to legal bit depths. */ -PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p - true_bits)); -#endif - -#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ - defined(PNG_WRITE_INTERLACING_SUPPORTED) -/* Have the code handle the interlacing. Returns the number of passes. - * MUST be called before png_read_update_info or png_start_read_image, - * otherwise it will not have the desired effect. Note that it is still - * necessary to call png_read_row or png_read_rows png_get_image_height - * times for each pass. -*/ -PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); -#endif - -#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) -/* Invert monochrome files */ -PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); -#endif - -#ifdef PNG_READ_BACKGROUND_SUPPORTED -/* Handle alpha and tRNS by replacing with a background color. Prior to - * libpng-1.5.4 this API must not be called before the PNG file header has been - * read. Doing so will result in unexpected behavior and possible warnings or - * errors if the PNG file contains a bKGD chunk. - */ -PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, - png_const_color_16p background_color, int background_gamma_code, - int need_expand, double background_gamma)) -PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, - png_const_color_16p background_color, int background_gamma_code, - int need_expand, png_fixed_point background_gamma)) -#endif -#ifdef PNG_READ_BACKGROUND_SUPPORTED -# define PNG_BACKGROUND_GAMMA_UNKNOWN 0 -# define PNG_BACKGROUND_GAMMA_SCREEN 1 -# define PNG_BACKGROUND_GAMMA_FILE 2 -# define PNG_BACKGROUND_GAMMA_UNIQUE 3 -#endif - -#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED -/* Scale a 16-bit depth file down to 8-bit, accurately. */ -PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); -#endif - -#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED -#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ -/* Strip the second byte of information from a 16-bit depth file. */ -PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); -#endif - -#ifdef PNG_READ_QUANTIZE_SUPPORTED -/* Turn on quantizing, and reduce the palette to the number of colors - * available. - */ -PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, - png_colorp palette, int num_palette, int maximum_colors, - png_const_uint_16p histogram, int full_quantize)); -#endif - -#ifdef PNG_READ_GAMMA_SUPPORTED -/* The threshold on gamma processing is configurable but hard-wired into the - * library. The following is the floating point variant. - */ -#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) - -/* Handle gamma correction. Screen_gamma=(display_exponent). - * NOTE: this API simply sets the screen and file gamma values. It will - * therefore override the value for gamma in a PNG file if it is called after - * the file header has been read - use with care - call before reading the PNG - * file for best results! - * - * These routines accept the same gamma values as png_set_alpha_mode (described - * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either - * API (floating point or fixed.) Notice, however, that the 'file_gamma' value - * is the inverse of a 'screen gamma' value. - */ -PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, - double screen_gamma, double override_file_gamma)) -PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, - png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) -#endif - -#ifdef PNG_WRITE_FLUSH_SUPPORTED -/* Set how many lines between output flushes - 0 for no flushing */ -PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); -/* Flush the current PNG output buffer */ -PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); -#endif - -/* Optional update palette with requested transformations */ -PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); - -/* Optional call to update the users info structure */ -PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, - png_inforp info_ptr)); - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read one or more rows of image data. */ -PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, - png_bytepp display_row, png_uint_32 num_rows)); -#endif - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read a row of data. */ -PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, - png_bytep display_row)); -#endif - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read the whole image into memory at once. */ -PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); -#endif - -/* Write a row of image data */ -PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, - png_const_bytep row)); - -/* Write a few rows of image data: (*row) is not written; however, the type - * is declared as writeable to maintain compatibility with previous versions - * of libpng and to allow the 'display_row' array from read_rows to be passed - * unchanged to write_rows. - */ -PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, - png_uint_32 num_rows)); - -/* Write the image data */ -PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); - -/* Write the end of the PNG file. */ -PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, - png_inforp info_ptr)); - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read the end of the PNG file. */ -PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); -#endif - -/* Free any memory associated with the png_info_struct */ -PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, - png_infopp info_ptr_ptr)); - -/* Free any memory associated with the png_struct and the png_info_structs */ -PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, - png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); - -/* Free any memory associated with the png_struct and the png_info_structs */ -PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, - png_infopp info_ptr_ptr)); - -/* Set the libpng method of handling chunk CRC errors */ -PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, - int ancil_action)); - -/* Values for png_set_crc_action() say how to handle CRC errors in - * ancillary and critical chunks, and whether to use the data contained - * therein. Note that it is impossible to "discard" data in a critical - * chunk. For versions prior to 0.90, the action was always error/quit, - * whereas in version 0.90 and later, the action for CRC errors in ancillary - * chunks is warn/discard. These values should NOT be changed. - * - * value action:critical action:ancillary - */ -#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ -#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ -#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ -#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ -#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ -#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ - -#ifdef PNG_WRITE_SUPPORTED -/* These functions give the user control over the scan-line filtering in - * libpng and the compression methods used by zlib. These functions are - * mainly useful for testing, as the defaults should work with most users. - * Those users who are tight on memory or want faster performance at the - * expense of compression can modify them. See the compression library - * header file (zlib.h) for an explination of the compression functions. - */ - -/* Set the filtering method(s) used by libpng. Currently, the only valid - * value for "method" is 0. - */ -PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, - int filters)); -#endif /* WRITE */ - -/* Flags for png_set_filter() to say which filters to use. The flags - * are chosen so that they don't conflict with real filter types - * below, in case they are supplied instead of the #defined constants. - * These values should NOT be changed. - */ -#define PNG_NO_FILTERS 0x00 -#define PNG_FILTER_NONE 0x08 -#define PNG_FILTER_SUB 0x10 -#define PNG_FILTER_UP 0x20 -#define PNG_FILTER_AVG 0x40 -#define PNG_FILTER_PAETH 0x80 -#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) -#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) - -/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. - * These defines should NOT be changed. - */ -#define PNG_FILTER_VALUE_NONE 0 -#define PNG_FILTER_VALUE_SUB 1 -#define PNG_FILTER_VALUE_UP 2 -#define PNG_FILTER_VALUE_AVG 3 -#define PNG_FILTER_VALUE_PAETH 4 -#define PNG_FILTER_VALUE_LAST 5 - -#ifdef PNG_WRITE_SUPPORTED -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ -PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, - int heuristic_method, int num_weights, png_const_doublep filter_weights, - png_const_doublep filter_costs)) -PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, - (png_structrp png_ptr, int heuristic_method, int num_weights, - png_const_fixed_point_p filter_weights, - png_const_fixed_point_p filter_costs)) -#endif /* WRITE_WEIGHTED_FILTER */ - -/* The following are no longer used and will be removed from libpng-1.7: */ -#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ -#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ -#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ -#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ - -/* Set the library compression level. Currently, valid values range from - * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 - * (0 - no compression, 9 - "maximal" compression). Note that tests have - * shown that zlib compression levels 3-6 usually perform as well as level 9 - * for PNG images, and do considerably fewer caclulations. In the future, - * these values may not correspond directly to the zlib compression levels. - */ -#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED -PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, - int level)); - -PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, - int mem_level)); - -PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, - int strategy)); - -/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a - * smaller value of window_bits if it can do so safely. - */ -PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, - int window_bits)); - -PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, - int method)); -#endif /* WRITE_CUSTOMIZE_COMPRESSION */ - -#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED -/* Also set zlib parameters for compressing non-IDAT chunks */ -PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, - int level)); - -PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, - int mem_level)); - -PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, - int strategy)); - -/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a - * smaller value of window_bits if it can do so safely. - */ -PNG_EXPORT(225, void, png_set_text_compression_window_bits, - (png_structrp png_ptr, int window_bits)); - -PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, - int method)); -#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ -#endif /* WRITE */ - -/* These next functions are called for input/output, memory, and error - * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, - * and call standard C I/O routines such as fread(), fwrite(), and - * fprintf(). These functions can be made to use other I/O routines - * at run time for those applications that need to handle I/O in a - * different manner by calling png_set_???_fn(). See libpng-manual.txt for - * more information. - */ - -#ifdef PNG_STDIO_SUPPORTED -/* Initialize the input/output for the PNG file to the default functions. */ -PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); -#endif - -/* Replace the (error and abort), and warning functions with user - * supplied functions. If no messages are to be printed you must still - * write and use replacement functions. The replacement error_fn should - * still do a longjmp to the last setjmp location if you are using this - * method of error handling. If error_fn or warning_fn is NULL, the - * default function will be used. - */ - -PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, - png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); - -/* Return the user pointer associated with the error functions */ -PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); - -/* Replace the default data output functions with a user supplied one(s). - * If buffered output is not used, then output_flush_fn can be set to NULL. - * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time - * output_flush_fn will be ignored (and thus can be NULL). - * It is probably a mistake to use NULL for output_flush_fn if - * write_data_fn is not also NULL unless you have built libpng with - * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's - * default flush function, which uses the standard *FILE structure, will - * be used. - */ -PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, - png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); - -/* Replace the default data input function with a user supplied one. */ -PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, - png_rw_ptr read_data_fn)); - -/* Return the user pointer associated with the I/O functions */ -PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); - -PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, - png_read_status_ptr read_row_fn)); - -PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, - png_write_status_ptr write_row_fn)); - -#ifdef PNG_USER_MEM_SUPPORTED -/* Replace the default memory allocation functions with user supplied one(s). */ -PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, - png_malloc_ptr malloc_fn, png_free_ptr free_fn)); -/* Return the user pointer associated with the memory functions */ -PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); -#endif - -#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED -PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, - png_user_transform_ptr read_user_transform_fn)); -#endif - -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED -PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, - png_user_transform_ptr write_user_transform_fn)); -#endif - -#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED -PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, - png_voidp user_transform_ptr, int user_transform_depth, - int user_transform_channels)); -/* Return the user pointer associated with the user transform functions */ -PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, - (png_const_structrp png_ptr)); -#endif - -#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED -/* Return information about the row currently being processed. Note that these - * APIs do not fail but will return unexpected results if called outside a user - * transform callback. Also note that when transforming an interlaced image the - * row number is the row number within the sub-image of the interlace pass, so - * the value will increase to the height of the sub-image (not the full image) - * then reset to 0 for the next pass. - * - * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to - * find the output pixel (x,y) given an interlaced sub-image pixel - * (row,col,pass). (See below for these macros.) - */ -PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); -PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); -#endif - -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED -/* This callback is called only for *unknown* chunks. If - * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known - * chunks to be treated as unknown, however in this case the callback must do - * any processing required by the chunk (e.g. by calling the appropriate - * png_set_ APIs.) - * - * There is no write support - on write, by default, all the chunks in the - * 'unknown' list are written in the specified position. - * - * The integer return from the callback function is interpreted thus: - * - * negative: An error occurred; png_chunk_error will be called. - * zero: The chunk was not handled, the chunk will be saved. A critical - * chunk will cause an error at this point unless it is to be saved. - * positive: The chunk was handled, libpng will ignore/discard it. - * - * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about - * how this behavior will change in libpng 1.7 - */ -PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, - png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); -#endif - -#ifdef PNG_USER_CHUNKS_SUPPORTED -PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); -#endif - -#ifdef PNG_PROGRESSIVE_READ_SUPPORTED -/* Sets the function callbacks for the push reader, and a pointer to a - * user-defined structure available to the callback functions. - */ -PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, - png_voidp progressive_ptr, png_progressive_info_ptr info_fn, - png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); - -/* Returns the user pointer associated with the push read functions */ -PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, - (png_const_structrp png_ptr)); - -/* Function to be called when data becomes available */ -PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, - png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); - -/* A function which may be called *only* within png_process_data to stop the - * processing of any more data. The function returns the number of bytes - * remaining, excluding any that libpng has cached internally. A subsequent - * call to png_process_data must supply these bytes again. If the argument - * 'save' is set to true the routine will first save all the pending data and - * will always return 0. - */ -PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); - -/* A function which may be called *only* outside (after) a call to - * png_process_data. It returns the number of bytes of data to skip in the - * input. Normally it will return 0, but if it returns a non-zero value the - * application must skip than number of bytes of input data and pass the - * following data to the next call to png_process_data. - */ -PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); - -/* Function that combines rows. 'new_row' is a flag that should come from - * the callback and be non-NULL if anything needs to be done; the library - * stores its own version of the new data internally and ignores the passed - * in value. - */ -PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, - png_bytep old_row, png_const_bytep new_row)); -#endif /* PROGRESSIVE_READ */ - -PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, - png_alloc_size_t size), PNG_ALLOCATED); -/* Added at libpng version 1.4.0 */ -PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, - png_alloc_size_t size), PNG_ALLOCATED); - -/* Added at libpng version 1.2.4 */ -PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, - png_alloc_size_t size), PNG_ALLOCATED); - -/* Frees a pointer allocated by png_malloc() */ -PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); - -/* Free data that was allocated internally */ -PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, - png_inforp info_ptr, png_uint_32 free_me, int num)); - -/* Reassign responsibility for freeing existing data, whether allocated - * by libpng or by the application; this works on the png_info structure passed - * in, it does not change the state for other png_info structures. - * - * It is unlikely that this function works correctly as of 1.6.0 and using it - * may result either in memory leaks or double free of allocated data. - */ -PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, - png_inforp info_ptr, int freer, png_uint_32 mask)); - -/* Assignments for png_data_freer */ -#define PNG_DESTROY_WILL_FREE_DATA 1 -#define PNG_SET_WILL_FREE_DATA 1 -#define PNG_USER_WILL_FREE_DATA 2 -/* Flags for png_ptr->free_me and info_ptr->free_me */ -#define PNG_FREE_HIST 0x0008U -#define PNG_FREE_ICCP 0x0010U -#define PNG_FREE_SPLT 0x0020U -#define PNG_FREE_ROWS 0x0040U -#define PNG_FREE_PCAL 0x0080U -#define PNG_FREE_SCAL 0x0100U -#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED -# define PNG_FREE_UNKN 0x0200U -#endif -/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ -#define PNG_FREE_PLTE 0x1000U -#define PNG_FREE_TRNS 0x2000U -#define PNG_FREE_TEXT 0x4000U -#define PNG_FREE_ALL 0x7fffU -#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ - -#ifdef PNG_USER_MEM_SUPPORTED -PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, - png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); -PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, - png_voidp ptr), PNG_DEPRECATED); -#endif - -#ifdef PNG_ERROR_TEXT_SUPPORTED -/* Fatal error in PNG image of libpng - can't continue */ -PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, - png_const_charp error_message), PNG_NORETURN); - -/* The same, but the chunk name is prepended to the error string. */ -PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, - png_const_charp error_message), PNG_NORETURN); - -#else -/* Fatal error in PNG image of libpng - can't continue */ -PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); -# define png_error(s1,s2) png_err(s1) -# define png_chunk_error(s1,s2) png_err(s1) -#endif - -#ifdef PNG_WARNINGS_SUPPORTED -/* Non-fatal error in libpng. Can continue, but may have a problem. */ -PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, - png_const_charp warning_message)); - -/* Non-fatal error in libpng, chunk name is prepended to message. */ -PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, - png_const_charp warning_message)); -#else -# define png_warning(s1,s2) ((void)(s1)) -# define png_chunk_warning(s1,s2) ((void)(s1)) -#endif - -#ifdef PNG_BENIGN_ERRORS_SUPPORTED -/* Benign error in libpng. Can continue, but may have a problem. - * User can choose whether to handle as a fatal error or as a warning. */ -PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, - png_const_charp warning_message)); - -#ifdef PNG_READ_SUPPORTED -/* Same, chunk name is prepended to message (only during read) */ -PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, - png_const_charp warning_message)); -#endif - -PNG_EXPORT(109, void, png_set_benign_errors, - (png_structrp png_ptr, int allowed)); -#else -# ifdef PNG_ALLOW_BENIGN_ERRORS -# define png_benign_error png_warning -# define png_chunk_benign_error png_chunk_warning -# else -# define png_benign_error png_error -# define png_chunk_benign_error png_chunk_error -# endif -#endif - -/* The png_set_<chunk> functions are for storing values in the png_info_struct. - * Similarly, the png_get_<chunk> calls are used to read values from the - * png_info_struct, either storing the parameters in the passed variables, or - * setting pointers into the png_info_struct where the data is stored. The - * png_get_<chunk> functions return a non-zero value if the data was available - * in info_ptr, or return zero and do not change any of the parameters if the - * data was not available. - * - * These functions should be used instead of directly accessing png_info - * to avoid problems with future changes in the size and internal layout of - * png_info_struct. - */ -/* Returns "flag" if chunk data is valid in info_ptr. */ -PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, - png_const_inforp info_ptr, png_uint_32 flag)); - -/* Returns number of bytes needed to hold a transformed row. */ -PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -#ifdef PNG_INFO_IMAGE_SUPPORTED -/* Returns row_pointers, which is an array of pointers to scanlines that was - * returned from png_read_png(). - */ -PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -/* Set row_pointers, which is an array of pointers to scanlines for use - * by png_write_png(). - */ -PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, - png_inforp info_ptr, png_bytepp row_pointers)); -#endif - -/* Returns number of color channels in image. */ -PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -#ifdef PNG_EASY_ACCESS_SUPPORTED -/* Returns image width in pixels. */ -PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -/* Returns image height in pixels. */ -PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -/* Returns image bit_depth. */ -PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -/* Returns image color_type. */ -PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -/* Returns image filter_type. */ -PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -/* Returns image interlace_type. */ -PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -/* Returns image compression_type. */ -PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); - -/* Returns image resolution in pixels per meter, from pHYs chunk data. */ -PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); -PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); -PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); - -/* Returns pixel aspect ratio, computed from pHYs chunk data. */ -PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, - (png_const_structrp png_ptr, png_const_inforp info_ptr)) -PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, - (png_const_structrp png_ptr, png_const_inforp info_ptr)) - -/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ -PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); -PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); -PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); -PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); - -#endif /* EASY_ACCESS */ - -#ifdef PNG_READ_SUPPORTED -/* Returns pointer to signature string read from PNG header */ -PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, - png_const_inforp info_ptr)); -#endif - -#ifdef PNG_bKGD_SUPPORTED -PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, - png_inforp info_ptr, png_color_16p *background)); -#endif - -#ifdef PNG_bKGD_SUPPORTED -PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_color_16p background)); -#endif - -#ifdef PNG_cHRM_SUPPORTED -PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, - png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, - double *red_y, double *green_x, double *green_y, double *blue_x, - double *blue_y)) -PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, - png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, - double *green_X, double *green_Y, double *green_Z, double *blue_X, - double *blue_Y, double *blue_Z)) -PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, - (png_const_structrp png_ptr, png_const_inforp info_ptr, - png_fixed_point *int_white_x, png_fixed_point *int_white_y, - png_fixed_point *int_red_x, png_fixed_point *int_red_y, - png_fixed_point *int_green_x, png_fixed_point *int_green_y, - png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) -PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, - (png_const_structrp png_ptr, png_const_inforp info_ptr, - png_fixed_point *int_red_X, png_fixed_point *int_red_Y, - png_fixed_point *int_red_Z, png_fixed_point *int_green_X, - png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, - png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, - png_fixed_point *int_blue_Z)) -#endif - -#ifdef PNG_cHRM_SUPPORTED -PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, - png_inforp info_ptr, - double white_x, double white_y, double red_x, double red_y, double green_x, - double green_y, double blue_x, double blue_y)) -PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, - png_inforp info_ptr, double red_X, double red_Y, double red_Z, - double green_X, double green_Y, double green_Z, double blue_X, - double blue_Y, double blue_Z)) -PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, - png_inforp info_ptr, png_fixed_point int_white_x, - png_fixed_point int_white_y, png_fixed_point int_red_x, - png_fixed_point int_red_y, png_fixed_point int_green_x, - png_fixed_point int_green_y, png_fixed_point int_blue_x, - png_fixed_point int_blue_y)) -PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, - png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, - png_fixed_point int_red_Z, png_fixed_point int_green_X, - png_fixed_point int_green_Y, png_fixed_point int_green_Z, - png_fixed_point int_blue_X, png_fixed_point int_blue_Y, - png_fixed_point int_blue_Z)) -#endif - -#ifdef PNG_gAMA_SUPPORTED -PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, - png_const_inforp info_ptr, double *file_gamma)) -PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, - (png_const_structrp png_ptr, png_const_inforp info_ptr, - png_fixed_point *int_file_gamma)) -#endif - -#ifdef PNG_gAMA_SUPPORTED -PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, - png_inforp info_ptr, double file_gamma)) -PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, - png_inforp info_ptr, png_fixed_point int_file_gamma)) -#endif - -#ifdef PNG_hIST_SUPPORTED -PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, - png_inforp info_ptr, png_uint_16p *hist)); -#endif - -#ifdef PNG_hIST_SUPPORTED -PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_uint_16p hist)); -#endif - -PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, - png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, - int *bit_depth, int *color_type, int *interlace_method, - int *compression_method, int *filter_method)); - -PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, - png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, - int color_type, int interlace_method, int compression_method, - int filter_method)); - -#ifdef PNG_oFFs_SUPPORTED -PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, - png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, - int *unit_type)); -#endif - -#ifdef PNG_oFFs_SUPPORTED -PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, - png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, - int unit_type)); -#endif - -#ifdef PNG_pCAL_SUPPORTED -PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, - png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, - png_int_32 *X1, int *type, int *nparams, png_charp *units, - png_charpp *params)); -#endif - -#ifdef PNG_pCAL_SUPPORTED -PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, - int type, int nparams, png_const_charp units, png_charpp params)); -#endif - -#ifdef PNG_pHYs_SUPPORTED -PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, - png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, - int *unit_type)); -#endif - -#ifdef PNG_pHYs_SUPPORTED -PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, - png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); -#endif - -PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, - png_inforp info_ptr, png_colorp *palette, int *num_palette)); - -PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, - png_inforp info_ptr, png_const_colorp palette, int num_palette)); - -#ifdef PNG_sBIT_SUPPORTED -PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, - png_inforp info_ptr, png_color_8p *sig_bit)); -#endif - -#ifdef PNG_sBIT_SUPPORTED -PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_color_8p sig_bit)); -#endif - -#ifdef PNG_sRGB_SUPPORTED -PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, - png_const_inforp info_ptr, int *file_srgb_intent)); -#endif - -#ifdef PNG_sRGB_SUPPORTED -PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, - png_inforp info_ptr, int srgb_intent)); -PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, - png_inforp info_ptr, int srgb_intent)); -#endif - -#ifdef PNG_iCCP_SUPPORTED -PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, - png_inforp info_ptr, png_charpp name, int *compression_type, - png_bytepp profile, png_uint_32 *proflen)); -#endif - -#ifdef PNG_iCCP_SUPPORTED -PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_charp name, int compression_type, - png_const_bytep profile, png_uint_32 proflen)); -#endif - -#ifdef PNG_sPLT_SUPPORTED -PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, - png_inforp info_ptr, png_sPLT_tpp entries)); -#endif - -#ifdef PNG_sPLT_SUPPORTED -PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); -#endif - -#ifdef PNG_TEXT_SUPPORTED -/* png_get_text also returns the number of text chunks in *num_text */ -PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, - png_inforp info_ptr, png_textp *text_ptr, int *num_text)); -#endif - -/* Note while png_set_text() will accept a structure whose text, - * language, and translated keywords are NULL pointers, the structure - * returned by png_get_text will always contain regular - * zero-terminated C strings. They might be empty strings but - * they will never be NULL pointers. - */ - -#ifdef PNG_TEXT_SUPPORTED -PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_textp text_ptr, int num_text)); -#endif - -#ifdef PNG_tIME_SUPPORTED -PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, - png_inforp info_ptr, png_timep *mod_time)); -#endif - -#ifdef PNG_tIME_SUPPORTED -PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_timep mod_time)); -#endif - -#ifdef PNG_tRNS_SUPPORTED -PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, - png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, - png_color_16p *trans_color)); -#endif - -#ifdef PNG_tRNS_SUPPORTED -PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, - png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, - png_const_color_16p trans_color)); -#endif - -#ifdef PNG_sCAL_SUPPORTED -PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, - png_const_inforp info_ptr, int *unit, double *width, double *height)) -#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ - defined(PNG_FLOATING_POINT_SUPPORTED) -/* NOTE: this API is currently implemented using floating point arithmetic, - * consequently it can only be used on systems with floating point support. - * In any case the range of values supported by png_fixed_point is small and it - * is highly recommended that png_get_sCAL_s be used instead. - */ -PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, - (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, - png_fixed_point *width, png_fixed_point *height)) -#endif -PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, - (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, - png_charpp swidth, png_charpp sheight)); - -PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, - png_inforp info_ptr, int unit, double width, double height)) -PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, - png_inforp info_ptr, int unit, png_fixed_point width, - png_fixed_point height)) -PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, - png_inforp info_ptr, int unit, - png_const_charp swidth, png_const_charp sheight)); -#endif /* sCAL */ - -#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED -/* Provide the default handling for all unknown chunks or, optionally, for - * specific unknown chunks. - * - * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was - * ignored and the default was used, the per-chunk setting only had an effect on - * write. If you wish to have chunk-specific handling on read in code that must - * work on earlier versions you must use a user chunk callback to specify the - * desired handling (keep or discard.) - * - * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The - * parameter is interpreted as follows: - * - * READ: - * PNG_HANDLE_CHUNK_AS_DEFAULT: - * Known chunks: do normal libpng processing, do not keep the chunk (but - * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) - * Unknown chunks: for a specific chunk use the global default, when used - * as the default discard the chunk data. - * PNG_HANDLE_CHUNK_NEVER: - * Discard the chunk data. - * PNG_HANDLE_CHUNK_IF_SAFE: - * Keep the chunk data if the chunk is not critical else raise a chunk - * error. - * PNG_HANDLE_CHUNK_ALWAYS: - * Keep the chunk data. - * - * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, - * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent - * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks - * it simply resets the behavior to the libpng default. - * - * INTERACTION WTIH USER CHUNK CALLBACKS: - * The per-chunk handling is always used when there is a png_user_chunk_ptr - * callback and the callback returns 0; the chunk is then always stored *unless* - * it is critical and the per-chunk setting is other than ALWAYS. Notice that - * the global default is *not* used in this case. (In effect the per-chunk - * value is incremented to at least IF_SAFE.) - * - * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and - * per-chunk defaults will be honored. If you want to preserve the current - * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE - * as the default - if you don't do this libpng 1.6 will issue a warning. - * - * If you want unhandled unknown chunks to be discarded in libpng 1.6 and - * earlier simply return '1' (handled). - * - * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: - * If this is *not* set known chunks will always be handled by libpng and - * will never be stored in the unknown chunk list. Known chunks listed to - * png_set_keep_unknown_chunks will have no effect. If it is set then known - * chunks listed with a keep other than AS_DEFAULT will *never* be processed - * by libpng, in addition critical chunks must either be processed by the - * callback or saved. - * - * The IHDR and IEND chunks must not be listed. Because this turns off the - * default handling for chunks that would otherwise be recognized the - * behavior of libpng transformations may well become incorrect! - * - * WRITE: - * When writing chunks the options only apply to the chunks specified by - * png_set_unknown_chunks (below), libpng will *always* write known chunks - * required by png_set_ calls and will always write the core critical chunks - * (as required for PLTE). - * - * Each chunk in the png_set_unknown_chunks list is looked up in the - * png_set_keep_unknown_chunks list to find the keep setting, this is then - * interpreted as follows: - * - * PNG_HANDLE_CHUNK_AS_DEFAULT: - * Write safe-to-copy chunks and write other chunks if the global - * default is set to _ALWAYS, otherwise don't write this chunk. - * PNG_HANDLE_CHUNK_NEVER: - * Do not write the chunk. - * PNG_HANDLE_CHUNK_IF_SAFE: - * Write the chunk if it is safe-to-copy, otherwise do not write it. - * PNG_HANDLE_CHUNK_ALWAYS: - * Write the chunk. - * - * Note that the default behavior is effectively the opposite of the read case - - * in read unknown chunks are not stored by default, in write they are written - * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different - * - on write the safe-to-copy bit is checked, on read the critical bit is - * checked and on read if the chunk is critical an error will be raised. - * - * num_chunks: - * =========== - * If num_chunks is positive, then the "keep" parameter specifies the manner - * for handling only those chunks appearing in the chunk_list array, - * otherwise the chunk list array is ignored. - * - * If num_chunks is 0 the "keep" parameter specifies the default behavior for - * unknown chunks, as described above. - * - * If num_chunks is negative, then the "keep" parameter specifies the manner - * for handling all unknown chunks plus all chunks recognized by libpng - * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to - * be processed by libpng. - */ -PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, - int keep, png_const_bytep chunk_list, int num_chunks)); - -/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; - * the result is therefore true (non-zero) if special handling is required, - * false for the default handling. - */ -PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, - png_const_bytep chunk_name)); -#endif - -#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED -PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, - png_inforp info_ptr, png_const_unknown_chunkp unknowns, - int num_unknowns)); - /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added - * unknowns to the location currently stored in the png_struct. This is - * invariably the wrong value on write. To fix this call the following API - * for each chunk in the list with the correct location. If you know your - * code won't be compiled on earlier versions you can rely on - * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing - * the correct thing. - */ - -PNG_EXPORT(175, void, png_set_unknown_chunk_location, - (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); - -PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, - png_inforp info_ptr, png_unknown_chunkpp entries)); -#endif - -/* Png_free_data() will turn off the "valid" flag for anything it frees. - * If you need to turn it off for a chunk that your application has freed, - * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); - */ -PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, - png_inforp info_ptr, int mask)); - -#ifdef PNG_INFO_IMAGE_SUPPORTED -/* The "params" pointer is currently not used and is for future expansion. */ -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, - int transforms, png_voidp params)); -#endif -#ifdef PNG_WRITE_SUPPORTED -PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, - int transforms, png_voidp params)); -#endif -#endif - -PNG_EXPORT(180, png_const_charp, png_get_copyright, - (png_const_structrp png_ptr)); -PNG_EXPORT(181, png_const_charp, png_get_header_ver, - (png_const_structrp png_ptr)); -PNG_EXPORT(182, png_const_charp, png_get_header_version, - (png_const_structrp png_ptr)); -PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, - (png_const_structrp png_ptr)); - -#ifdef PNG_MNG_FEATURES_SUPPORTED -PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, - png_uint_32 mng_features_permitted)); -#endif - -/* For use in png_set_keep_unknown, added to version 1.2.6 */ -#define PNG_HANDLE_CHUNK_AS_DEFAULT 0 -#define PNG_HANDLE_CHUNK_NEVER 1 -#define PNG_HANDLE_CHUNK_IF_SAFE 2 -#define PNG_HANDLE_CHUNK_ALWAYS 3 -#define PNG_HANDLE_CHUNK_LAST 4 - -/* Strip the prepended error numbers ("#nnn ") from error and warning - * messages before passing them to the error or warning handler. - */ -#ifdef PNG_ERROR_NUMBERS_SUPPORTED -PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, - png_uint_32 strip_mode)); -#endif - -/* Added in libpng-1.2.6 */ -#ifdef PNG_SET_USER_LIMITS_SUPPORTED -PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, - png_uint_32 user_width_max, png_uint_32 user_height_max)); -PNG_EXPORT(187, png_uint_32, png_get_user_width_max, - (png_const_structrp png_ptr)); -PNG_EXPORT(188, png_uint_32, png_get_user_height_max, - (png_const_structrp png_ptr)); -/* Added in libpng-1.4.0 */ -PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, - png_uint_32 user_chunk_cache_max)); -PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, - (png_const_structrp png_ptr)); -/* Added in libpng-1.4.1 */ -PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, - png_alloc_size_t user_chunk_cache_max)); -PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, - (png_const_structrp png_ptr)); -#endif - -#if defined(PNG_INCH_CONVERSIONS_SUPPORTED) -PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); - -PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); - -PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, - (png_const_structrp png_ptr, png_const_inforp info_ptr)); - -PNG_FP_EXPORT(196, float, png_get_x_offset_inches, - (png_const_structrp png_ptr, png_const_inforp info_ptr)) -#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ -PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, - (png_const_structrp png_ptr, png_const_inforp info_ptr)) -#endif - -PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, - png_const_inforp info_ptr)) -#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ -PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, - (png_const_structrp png_ptr, png_const_inforp info_ptr)) -#endif - -# ifdef PNG_pHYs_SUPPORTED -PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, - png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, - int *unit_type)); -# endif /* pHYs */ -#endif /* INCH_CONVERSIONS */ - -/* Added in libpng-1.4.0 */ -#ifdef PNG_IO_STATE_SUPPORTED -PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); - -/* Removed from libpng 1.6; use png_get_io_chunk_type. */ -PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), - PNG_DEPRECATED) - -PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, - (png_const_structrp png_ptr)); - -/* The flags returned by png_get_io_state() are the following: */ -# define PNG_IO_NONE 0x0000 /* no I/O at this moment */ -# define PNG_IO_READING 0x0001 /* currently reading */ -# define PNG_IO_WRITING 0x0002 /* currently writing */ -# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ -# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ -# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ -# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ -# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ -# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ -#endif /* IO_STATE */ - -/* Interlace support. The following macros are always defined so that if - * libpng interlace handling is turned off the macros may be used to handle - * interlaced images within the application. - */ -#define PNG_INTERLACE_ADAM7_PASSES 7 - -/* Two macros to return the first row and first column of the original, - * full, image which appears in a given pass. 'pass' is in the range 0 - * to 6 and the result is in the range 0 to 7. - */ -#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) -#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) - -/* A macro to return the offset between pixels in the output row for a pair of - * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that - * follows. Note that ROW_OFFSET is the offset from one row to the next whereas - * COL_OFFSET is from one column to the next, within a row. - */ -#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) -#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) - -/* Two macros to help evaluate the number of rows or columns in each - * pass. This is expressed as a shift - effectively log2 of the number or - * rows or columns in each 8x8 tile of the original image. - */ -#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) -#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) - -/* Hence two macros to determine the number of rows or columns in a given - * pass of an image given its height or width. In fact these macros may - * return non-zero even though the sub-image is empty, because the other - * dimension may be empty for a small image. - */ -#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ - -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) -#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ - -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) - -/* For the reader row callbacks (both progressive and sequential) it is - * necessary to find the row in the output image given a row in an interlaced - * image, so two more macros: - */ -#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ - (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) -#define PNG_COL_FROM_PASS_COL(x_in, pass) \ - (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) - -/* Two macros which return a boolean (0 or 1) saying whether the given row - * or column is in a particular pass. These use a common utility macro that - * returns a mask for a given pass - the offset 'off' selects the row or - * column version. The mask has the appropriate bit set for each column in - * the tile. - */ -#define PNG_PASS_MASK(pass,off) ( \ - ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ - ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) - -#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ - ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) -#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ - ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) - -#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED -/* With these routines we avoid an integer divide, which will be slower on - * most machines. However, it does take more operations than the corresponding - * divide method, so it may be slower on a few RISC systems. There are two - * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. - * - * Note that the rounding factors are NOT supposed to be the same! 128 and - * 32768 are correct for the NODIV code; 127 and 32767 are correct for the - * standard method. - * - * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] - */ - - /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ - -# define png_composite(composite, fg, alpha, bg) \ - { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ - * (png_uint_16)(alpha) \ - + (png_uint_16)(bg)*(png_uint_16)(255 \ - - (png_uint_16)(alpha)) + 128); \ - (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); } - -# define png_composite_16(composite, fg, alpha, bg) \ - { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ - * (png_uint_32)(alpha) \ - + (png_uint_32)(bg)*(65535 \ - - (png_uint_32)(alpha)) + 32768); \ - (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); } - -#else /* Standard method using integer division */ - -# define png_composite(composite, fg, alpha, bg) \ - (composite) = \ - (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ - (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ - 127) / 255)) - -# define png_composite_16(composite, fg, alpha, bg) \ - (composite) = \ - (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ - (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ - 32767) / 65535)) -#endif /* READ_COMPOSITE_NODIV */ - -#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED -PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); -PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); -PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); -#endif - -PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, - png_const_bytep buf)); -/* No png_get_int_16 -- may be added if there's a real need for it. */ - -/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ -#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED -PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); -#endif -#ifdef PNG_SAVE_INT_32_SUPPORTED -PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); -#endif - -/* Place a 16-bit number into a buffer in PNG byte order. - * The parameter is declared unsigned int, not png_uint_16, - * just to avoid potential problems on pre-ANSI C compilers. - */ -#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED -PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); -/* No png_save_int_16 -- may be added if there's a real need for it. */ -#endif - -#ifdef PNG_USE_READ_MACROS -/* Inline macros to do direct reads of bytes from the input buffer. - * The png_get_int_32() routine assumes we are using two's complement - * format for negative values, which is almost certainly true. - */ -# define PNG_get_uint_32(buf) \ - (((png_uint_32)(*(buf)) << 24) + \ - ((png_uint_32)(*((buf) + 1)) << 16) + \ - ((png_uint_32)(*((buf) + 2)) << 8) + \ - ((png_uint_32)(*((buf) + 3)))) - - /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the - * function) incorrectly returned a value of type png_uint_32. - */ -# define PNG_get_uint_16(buf) \ - ((png_uint_16) \ - (((unsigned int)(*(buf)) << 8) + \ - ((unsigned int)(*((buf) + 1))))) - -# define PNG_get_int_32(buf) \ - ((png_int_32)((*(buf) & 0x80) \ - ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ - : (png_int_32)png_get_uint_32(buf))) - - /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, - * but defining a macro name prefixed with PNG_PREFIX. - */ -# ifndef PNG_PREFIX -# define png_get_uint_32(buf) PNG_get_uint_32(buf) -# define png_get_uint_16(buf) PNG_get_uint_16(buf) -# define png_get_int_32(buf) PNG_get_int_32(buf) -# endif -#else -# ifdef PNG_PREFIX - /* No macros; revert to the (redefined) function */ -# define PNG_get_uint_32 (png_get_uint_32) -# define PNG_get_uint_16 (png_get_uint_16) -# define PNG_get_int_32 (png_get_int_32) -# endif -#endif - -#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED -PNG_EXPORT(242, void, png_set_check_for_invalid_index, - (png_structrp png_ptr, int allowed)); -# ifdef PNG_GET_PALETTE_MAX_SUPPORTED -PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, - png_const_infop info_ptr)); -# endif -#endif /* CHECK_FOR_INVALID_INDEX */ - -/******************************************************************************* - * Section 5: SIMPLIFIED API - ******************************************************************************* - * - * Please read the documentation in libpng-manual.txt (TODO: write said - * documentation) if you don't understand what follows. - * - * The simplified API hides the details of both libpng and the PNG file format - * itself. It allows PNG files to be read into a very limited number of - * in-memory bitmap formats or to be written from the same formats. If these - * formats do not accomodate your needs then you can, and should, use the more - * sophisticated APIs above - these support a wide variety of in-memory formats - * and a wide variety of sophisticated transformations to those formats as well - * as a wide variety of APIs to manipulate ancillary information. - * - * To read a PNG file using the simplified API: - * - * 1) Declare a 'png_image' structure (see below) on the stack, set the - * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL - * (this is REQUIRED, your program may crash if you don't do it.) - * 2) Call the appropriate png_image_begin_read... function. - * 3) Set the png_image 'format' member to the required sample format. - * 4) Allocate a buffer for the image and, if required, the color-map. - * 5) Call png_image_finish_read to read the image and, if required, the - * color-map into your buffers. - * - * There are no restrictions on the format of the PNG input itself; all valid - * color types, bit depths, and interlace methods are acceptable, and the - * input image is transformed as necessary to the requested in-memory format - * during the png_image_finish_read() step. The only caveat is that if you - * request a color-mapped image from a PNG that is full-color or makes - * complex use of an alpha channel the transformation is extremely lossy and the - * result may look terrible. - * - * To write a PNG file using the simplified API: - * - * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. - * 2) Initialize the members of the structure that describe the image, setting - * the 'format' member to the format of the image samples. - * 3) Call the appropriate png_image_write... function with a pointer to the - * image and, if necessary, the color-map to write the PNG data. - * - * png_image is a structure that describes the in-memory format of an image - * when it is being read or defines the in-memory format of an image that you - * need to write: - */ -#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ - defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) - -#define PNG_IMAGE_VERSION 1 - -typedef struct png_control *png_controlp; -typedef struct -{ - png_controlp opaque; /* Initialize to NULL, free with png_image_free */ - png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ - png_uint_32 width; /* Image width in pixels (columns) */ - png_uint_32 height; /* Image height in pixels (rows) */ - png_uint_32 format; /* Image format as defined below */ - png_uint_32 flags; /* A bit mask containing informational flags */ - png_uint_32 colormap_entries; - /* Number of entries in the color-map */ - - /* In the event of an error or warning the following field will be set to a - * non-zero value and the 'message' field will contain a '\0' terminated - * string with the libpng error or warning message. If both warnings and - * an error were encountered, only the error is recorded. If there - * are multiple warnings, only the first one is recorded. - * - * The upper 30 bits of this value are reserved, the low two bits contain - * a value as follows: - */ -# define PNG_IMAGE_WARNING 1 -# define PNG_IMAGE_ERROR 2 - /* - * The result is a two-bit code such that a value more than 1 indicates - * a failure in the API just called: - * - * 0 - no warning or error - * 1 - warning - * 2 - error - * 3 - error preceded by warning - */ -# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) - - png_uint_32 warning_or_error; - - char message[64]; -} png_image, *png_imagep; - -/* The samples of the image have one to four channels whose components have - * original values in the range 0 to 1.0: - * - * 1: A single gray or luminance channel (G). - * 2: A gray/luminance channel and an alpha channel (GA). - * 3: Three red, green, blue color channels (RGB). - * 4: Three color channels and an alpha channel (RGBA). - * - * The components are encoded in one of two ways: - * - * a) As a small integer, value 0..255, contained in a single byte. For the - * alpha channel the original value is simply value/255. For the color or - * luminance channels the value is encoded according to the sRGB specification - * and matches the 8-bit format expected by typical display devices. - * - * The color/gray channels are not scaled (pre-multiplied) by the alpha - * channel and are suitable for passing to color management software. - * - * b) As a value in the range 0..65535, contained in a 2-byte integer. All - * channels can be converted to the original value by dividing by 65535; all - * channels are linear. Color channels use the RGB encoding (RGB end-points) of - * the sRGB specification. This encoding is identified by the - * PNG_FORMAT_FLAG_LINEAR flag below. - * - * When the simplified API needs to convert between sRGB and linear colorspaces, - * the actual sRGB transfer curve defined in the sRGB specification (see the - * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 - * approximation used elsewhere in libpng. - * - * When an alpha channel is present it is expected to denote pixel coverage - * of the color or luminance channels and is returned as an associated alpha - * channel: the color/gray channels are scaled (pre-multiplied) by the alpha - * value. - * - * The samples are either contained directly in the image data, between 1 and 8 - * bytes per pixel according to the encoding, or are held in a color-map indexed - * by bytes in the image data. In the case of a color-map the color-map entries - * are individual samples, encoded as above, and the image data has one byte per - * pixel to select the relevant sample from the color-map. - */ - -/* PNG_FORMAT_* - * - * #defines to be used in png_image::format. Each #define identifies a - * particular layout of sample data and, if present, alpha values. There are - * separate defines for each of the two component encodings. - * - * A format is built up using single bit flag values. All combinations are - * valid. Formats can be built up from the flag values or you can use one of - * the predefined values below. When testing formats always use the FORMAT_FLAG - * macros to test for individual features - future versions of the library may - * add new flags. - * - * When reading or writing color-mapped images the format should be set to the - * format of the entries in the color-map then png_image_{read,write}_colormap - * called to read or write the color-map and set the format correctly for the - * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! - * - * NOTE: libpng can be built with particular features disabled. If you see - * compiler errors because the definition of one of the following flags has been - * compiled out it is because libpng does not have the required support. It is - * possible, however, for the libpng configuration to enable the format on just - * read or just write; in that case you may see an error at run time. You can - * guard against this by checking for the definition of the appropriate - * "_SUPPORTED" macro, one of: - * - * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED - */ -#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ -#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ -#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ -#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ - -#ifdef PNG_FORMAT_BGR_SUPPORTED -# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ -#endif - -#ifdef PNG_FORMAT_AFIRST_SUPPORTED -# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ -#endif - -/* Commonly used formats have predefined macros. - * - * First the single byte (sRGB) formats: - */ -#define PNG_FORMAT_GRAY 0 -#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA -#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) -#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR -#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) -#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) -#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) -#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) -#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) - -/* Then the linear 2-byte formats. When naming these "Y" is used to - * indicate a luminance (gray) channel. - */ -#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR -#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) -#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) -#define PNG_FORMAT_LINEAR_RGB_ALPHA \ - (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) - -/* With color-mapped formats the image data is one byte for each pixel, the byte - * is an index into the color-map which is formatted as above. To obtain a - * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP - * to one of the above definitions, or you can use one of the definitions below. - */ -#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) -#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) -#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) -#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) -#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) -#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) - -/* PNG_IMAGE macros - * - * These are convenience macros to derive information from a png_image - * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the - * actual image sample values - either the entries in the color-map or the - * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values - * for the pixels and will always return 1 for color-mapped formats. The - * remaining macros return information about the rows in the image and the - * complete image. - * - * NOTE: All the macros that take a png_image::format parameter are compile time - * constants if the format parameter is, itself, a constant. Therefore these - * macros can be used in array declarations and case labels where required. - * Similarly the macros are also pre-processor constants (sizeof is not used) so - * they can be used in #if tests. - * - * First the information about the samples. - */ -#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ - (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) - /* Return the total number of channels in a given format: 1..4 */ - -#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ - ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) - /* Return the size in bytes of a single component of a pixel or color-map - * entry (as appropriate) in the image: 1 or 2. - */ - -#define PNG_IMAGE_SAMPLE_SIZE(fmt)\ - (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) - /* This is the size of the sample data for one sample. If the image is - * color-mapped it is the size of one color-map entry (and image pixels are - * one byte in size), otherwise it is the size of one image pixel. - */ - -#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ - (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) - /* The maximum size of the color-map required by the format expressed in a - * count of components. This can be used to compile-time allocate a - * color-map: - * - * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; - * - * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; - * - * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the - * information from one of the png_image_begin_read_ APIs and dynamically - * allocate the required memory. - */ - -/* Corresponding information about the pixels */ -#define PNG_IMAGE_PIXEL_(test,fmt)\ - (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) - -#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ - PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) - /* The number of separate channels (components) in a pixel; 1 for a - * color-mapped image. - */ - -#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ - PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) - /* The size, in bytes, of each component in a pixel; 1 for a color-mapped - * image. - */ - -#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) - /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ - -/* Information about the whole row, or whole image */ -#define PNG_IMAGE_ROW_STRIDE(image)\ - (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) - /* Return the total number of components in a single row of the image; this - * is the minimum 'row stride', the minimum count of components between each - * row. For a color-mapped image this is the minimum number of bytes in a - * row. - * - * WARNING: this macro overflows for some images with more than one component - * and very large image widths. libpng will refuse to process an image where - * this macro would overflow. - */ - -#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ - (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) - /* Return the size, in bytes, of an image buffer given a png_image and a row - * stride - the number of components to leave space for in each row. - * - * WARNING: this macro overflows a 32-bit integer for some large PNG images, - * libpng will refuse to process an image where such an overflow would occur. - */ - -#define PNG_IMAGE_SIZE(image)\ - PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) - /* Return the size, in bytes, of the image in memory given just a png_image; - * the row stride is the minimum stride required for the image. - */ - -#define PNG_IMAGE_COLORMAP_SIZE(image)\ - (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) - /* Return the size, in bytes, of the color-map of this image. If the image - * format is not a color-map format this will return a size sufficient for - * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if - * you don't want to allocate a color-map in this case. - */ - -/* PNG_IMAGE_FLAG_* - * - * Flags containing additional information about the image are held in the - * 'flags' field of png_image. - */ -#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 - /* This indicates the the RGB values of the in-memory bitmap do not - * correspond to the red, green and blue end-points defined by sRGB. - */ - -#define PNG_IMAGE_FLAG_FAST 0x02 - /* On write emphasise speed over compression; the resultant PNG file will be - * larger but will be produced significantly faster, particular for large - * images. Do not use this option for images which will be distributed, only - * used it when producing intermediate files that will be read back in - * repeatedly. For a typical 24-bit image the option will double the read - * speed at the cost of increasing the image size by 25%, however for many - * more compressible images the PNG file can be 10 times larger with only a - * slight speed gain. - */ - -#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 - /* On read if the image is a 16-bit per component image and there is no gAMA - * or sRGB chunk assume that the components are sRGB encoded. Notice that - * images output by the simplified API always have gamma information; setting - * this flag only affects the interpretation of 16-bit images from an - * external source. It is recommended that the application expose this flag - * to the user; the user can normally easily recognize the difference between - * linear and sRGB encoding. This flag has no effect on write - the data - * passed to the write APIs must have the correct encoding (as defined - * above.) - * - * If the flag is not set (the default) input 16-bit per component data is - * assumed to be linear. - * - * NOTE: the flag can only be set after the png_image_begin_read_ call, - * because that call initializes the 'flags' field. - */ - -#ifdef PNG_SIMPLIFIED_READ_SUPPORTED -/* READ APIs - * --------- - * - * The png_image passed to the read APIs must have been initialized by setting - * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) - */ -#ifdef PNG_STDIO_SUPPORTED -PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, - const char *file_name)); - /* The named file is opened for read and the image header is filled in - * from the PNG header in the file. - */ - -PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, - FILE* file)); - /* The PNG header is read from the stdio FILE object. */ -#endif /* STDIO */ - -PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, - png_const_voidp memory, png_size_t size)); - /* The PNG header is read from the given memory buffer. */ - -PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, - png_const_colorp background, void *buffer, png_int_32 row_stride, - void *colormap)); - /* Finish reading the image into the supplied buffer and clean up the - * png_image structure. - * - * row_stride is the step, in byte or 2-byte units as appropriate, - * between adjacent rows. A positive stride indicates that the top-most row - * is first in the buffer - the normal top-down arrangement. A negative - * stride indicates that the bottom-most row is first in the buffer. - * - * background need only be supplied if an alpha channel must be removed from - * a png_byte format and the removal is to be done by compositing on a solid - * color; otherwise it may be NULL and any composition will be done directly - * onto the buffer. The value is an sRGB color to use for the background, - * for grayscale output the green channel is used. - * - * background must be supplied when an alpha channel must be removed from a - * single byte color-mapped output format, in other words if: - * - * 1) The original format from png_image_begin_read_from_* had - * PNG_FORMAT_FLAG_ALPHA set. - * 2) The format set by the application does not. - * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and - * PNG_FORMAT_FLAG_LINEAR *not* set. - * - * For linear output removing the alpha channel is always done by compositing - * on black and background is ignored. - * - * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must - * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. - * image->colormap_entries will be updated to the actual number of entries - * written to the colormap; this may be less than the original value. - */ - -PNG_EXPORT(238, void, png_image_free, (png_imagep image)); - /* Free any data allocated by libpng in image->opaque, setting the pointer to - * NULL. May be called at any time after the structure is initialized. - */ -#endif /* SIMPLIFIED_READ */ - -#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED -/* WRITE APIS - * ---------- - * For write you must initialize a png_image structure to describe the image to - * be written. To do this use memset to set the whole structure to 0 then - * initialize fields describing your image. - * - * version: must be set to PNG_IMAGE_VERSION - * opaque: must be initialized to NULL - * width: image width in pixels - * height: image height in rows - * format: the format of the data (image and color-map) you wish to write - * flags: set to 0 unless one of the defined flags applies; set - * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB - * values do not correspond to the colors in sRGB. - * colormap_entries: set to the number of entries in the color-map (0 to 256) - */ -#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED -PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, - const char *file, int convert_to_8bit, const void *buffer, - png_int_32 row_stride, const void *colormap)); - /* Write the image to the named file. */ - -PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, - int convert_to_8_bit, const void *buffer, png_int_32 row_stride, - const void *colormap)); - /* Write the image to the given (FILE*). */ -#endif /* SIMPLIFIED_WRITE_STDIO */ - -/* With all write APIs if image is in one of the linear formats with 16-bit - * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG - * gamma encoded according to the sRGB specification, otherwise a 16-bit linear - * encoded PNG file is written. - * - * With color-mapped data formats the colormap parameter point to a color-map - * with at least image->colormap_entries encoded in the specified format. If - * the format is linear the written PNG color-map will be converted to sRGB - * regardless of the convert_to_8_bit flag. - * - * With all APIs row_stride is handled as in the read APIs - it is the spacing - * from one row to the next in component sized units (1 or 2 bytes) and if - * negative indicates a bottom-up row layout in the buffer. If row_stride is - * zero, libpng will calculate it for you from the image width and number of - * channels. - * - * Note that the write API does not support interlacing, sub-8-bit pixels or - * most ancillary chunks. If you need to write text chunks (e.g. for copyright - * notices) you need to use one of the other APIs. - */ - -PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, - png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, - const void *buffer, png_int_32 row_stride, const void *colormap)); - /* Write the image to the given memory buffer. The function both writes the - * whole PNG data stream to *memory and updates *memory_bytes with the count - * of bytes written. - * - * 'memory' may be NULL. In this case *memory_bytes is not read however on - * success the number of bytes which would have been written will still be - * stored in *memory_bytes. On failure *memory_bytes will contain 0. - * - * If 'memory' is not NULL it must point to memory[*memory_bytes] of - * writeable memory. - * - * If the function returns success memory[*memory_bytes] (if 'memory' is not - * NULL) contains the written PNG data. *memory_bytes will always be less - * than or equal to the original value. - * - * If the function returns false and *memory_bytes was not changed an error - * occured during write. If *memory_bytes was changed, or is not 0 if - * 'memory' was NULL, the write would have succeeded but for the memory - * buffer being too small. *memory_bytes contains the required number of - * bytes and will be bigger that the original value. - */ - -#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ - row_stride, colormap)\ - png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ - row_stride, colormap) - /* Return the amount of memory in 'size' required to compress this image. - * The png_image structure 'image' must be filled in as in the above - * function and must not be changed before the actual write call, the buffer - * and all other parameters must also be identical to that in the final - * write call. The 'size' variable need not be initialized. - * - * NOTE: the macro returns true/false, if false is returned 'size' will be - * set to zero and the write failed and probably will fail if tried again. - */ - -/* You can pre-allocate the buffer by making sure it is of sufficient size - * regardless of the amount of compression achieved. The buffer size will - * always be bigger than the original image and it will never be filled. The - * following macros are provided to assist in allocating the buffer. - */ -#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) - /* The number of uncompressed bytes in the PNG byte encoding of the image; - * uncompressing the PNG IDAT data will give this number of bytes. - * - * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this - * macro can because of the extra bytes used in the PNG byte encoding. You - * need to avoid this macro if your image size approaches 2^30 in width or - * height. The same goes for the remainder of these macros; they all produce - * bigger numbers than the actual in-memory image size. - */ -#ifndef PNG_ZLIB_MAX_SIZE -# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) - /* An upper bound on the number of compressed bytes given 'b' uncompressed - * bytes. This is based on deflateBounds() in zlib; different - * implementations of zlib compression may conceivably produce more data so - * if your zlib implementation is not zlib itself redefine this macro - * appropriately. - */ -#endif - -#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ - PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) - /* An upper bound on the size of the data in the PNG IDAT chunks. */ - -#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ - ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ - (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ - 12U+3U*(image).colormap_entries/*PLTE data*/+\ - (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ - 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ - 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) - /* A helper for the following macro; if your compiler cannot handle the - * following macro use this one with the result of - * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most - * compilers should handle this just fine.) - */ - -#define PNG_IMAGE_PNG_SIZE_MAX(image)\ - PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) - /* An upper bound on the total length of the PNG data stream for 'image'. - * The result is of type png_alloc_size_t, on 32-bit systems this may - * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will - * run out of buffer space but return a corrected size which should work. - */ -#endif /* SIMPLIFIED_WRITE */ -/******************************************************************************* - * END OF SIMPLIFIED API - ******************************************************************************/ -#endif /* SIMPLIFIED_{READ|WRITE} */ - -/******************************************************************************* - * Section 6: IMPLEMENTATION OPTIONS - ******************************************************************************* - * - * Support for arbitrary implementation-specific optimizations. The API allows - * particular options to be turned on or off. 'Option' is the number of the - * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given - * by the PNG_OPTION_ defines below. - * - * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, - * are detected at run time, however sometimes it may be impossible - * to do this in user mode, in which case it is necessary to discover - * the capabilities in an OS specific way. Such capabilities are - * listed here when libpng has support for them and must be turned - * ON by the application if present. - * - * SOFTWARE: sometimes software optimizations actually result in performance - * decrease on some architectures or systems, or with some sets of - * PNG images. 'Software' options allow such optimizations to be - * selected at run time. - */ -#ifdef PNG_SET_OPTION_SUPPORTED -#ifdef PNG_ARM_NEON_API_SUPPORTED -# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ -#endif -#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ -#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ -#define PNG_OPTION_NEXT 6 /* Next option - numbers must be even */ - -/* Return values: NOTE: there are four values and 'off' is *not* zero */ -#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ -#define PNG_OPTION_INVALID 1 /* Option number out of range */ -#define PNG_OPTION_OFF 2 -#define PNG_OPTION_ON 3 - -PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, - int onoff)); -#endif /* SET_OPTION */ - -/******************************************************************************* - * END OF HARDWARE AND SOFTWARE OPTIONS - ******************************************************************************/ - -/* Maintainer: Put new public prototypes here ^, in libpng.3, in project - * defs, and in scripts/symbols.def. - */ - -/* The last ordinal number (this is the *last* one already used; the next - * one to use is one more than this.) - */ -#ifdef PNG_EXPORT_LAST_ORDINAL - PNG_EXPORT_LAST_ORDINAL(245); -#endif - -#ifdef __cplusplus -} -#endif - -#endif /* PNG_VERSION_INFO_ONLY */ -/* Do not put anything past this line */ -#endif /* PNG_H */ diff --git a/third_party/libpng/pngconf.h b/third_party/libpng/pngconf.h deleted file mode 100644 index 975f54c604..0000000000 --- a/third_party/libpng/pngconf.h +++ /dev/null @@ -1,622 +0,0 @@ - -/* pngconf.h - machine configurable file for libpng - * - * libpng version 1.6.22rc01, May 14, 2016 - * - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * Any machine specific code is near the front of this file, so if you - * are configuring libpng for a machine, you may want to read the section - * starting here down to where it starts to typedef png_color, png_text, - * and png_info. - */ - -#ifndef PNGCONF_H -#define PNGCONF_H - -#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */ - -/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C - * compiler for correct compilation. The following header files are required by - * the standard. If your compiler doesn't provide these header files, or they - * do not match the standard, you will need to provide/improve them. - */ -#include <limits.h> -#include <stddef.h> - -/* Library header files. These header files are all defined by ISOC90; libpng - * expects conformant implementations, however, an ISOC90 conformant system need - * not provide these header files if the functionality cannot be implemented. - * In this case it will be necessary to disable the relevant parts of libpng in - * the build of pnglibconf.h. - * - * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not - * include this unnecessary header file. - */ - -#ifdef PNG_STDIO_SUPPORTED - /* Required for the definition of FILE: */ -# include <stdio.h> -#endif - -#ifdef PNG_SETJMP_SUPPORTED - /* Required for the definition of jmp_buf and the declaration of longjmp: */ -# include <setjmp.h> -#endif - -#ifdef PNG_CONVERT_tIME_SUPPORTED - /* Required for struct tm: */ -# include <time.h> -#endif - -#endif /* PNG_BUILDING_SYMBOL_TABLE */ - -/* Prior to 1.6.0 it was possible to turn off 'const' in declarations using - * PNG_NO_CONST; this is no longer supported except for data declarations which - * apparently still cause problems in 2011 on some compilers. - */ -#define PNG_CONST const /* backward compatibility only */ - -/* This controls optimization of the reading of 16-bit and 32-bit values - * from PNG files. It can be set on a per-app-file basis - it - * just changes whether a macro is used when the function is called. - * The library builder sets the default; if read functions are not - * built into the library the macro implementation is forced on. - */ -#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED -# define PNG_USE_READ_MACROS -#endif -#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS) -# if PNG_DEFAULT_READ_MACROS -# define PNG_USE_READ_MACROS -# endif -#endif - -/* COMPILER SPECIFIC OPTIONS. - * - * These options are provided so that a variety of difficult compilers - * can be used. Some are fixed at build time (e.g. PNG_API_RULE - * below) but still have compiler specific implementations, others - * may be changed on a per-file basis when compiling against libpng. - */ - -/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect - * against legacy (pre ISOC90) compilers that did not understand function - * prototypes. It is not required for modern C compilers. - */ -#ifndef PNGARG -# define PNGARG(arglist) arglist -#endif - -/* Function calling conventions. - * ============================= - * Normally it is not necessary to specify to the compiler how to call - * a function - it just does it - however on x86 systems derived from - * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems - * and some others) there are multiple ways to call a function and the - * default can be changed on the compiler command line. For this reason - * libpng specifies the calling convention of every exported function and - * every function called via a user supplied function pointer. This is - * done in this file by defining the following macros: - * - * PNGAPI Calling convention for exported functions. - * PNGCBAPI Calling convention for user provided (callback) functions. - * PNGCAPI Calling convention used by the ANSI-C library (required - * for longjmp callbacks and sometimes used internally to - * specify the calling convention for zlib). - * - * These macros should never be overridden. If it is necessary to - * change calling convention in a private build this can be done - * by setting PNG_API_RULE (which defaults to 0) to one of the values - * below to select the correct 'API' variants. - * - * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout. - * This is correct in every known environment. - * PNG_API_RULE=1 Use the operating system convention for PNGAPI and - * the 'C' calling convention (from PNGCAPI) for - * callbacks (PNGCBAPI). This is no longer required - * in any known environment - if it has to be used - * please post an explanation of the problem to the - * libpng mailing list. - * - * These cases only differ if the operating system does not use the C - * calling convention, at present this just means the above cases - * (x86 DOS/Windows sytems) and, even then, this does not apply to - * Cygwin running on those systems. - * - * Note that the value must be defined in pnglibconf.h so that what - * the application uses to call the library matches the conventions - * set when building the library. - */ - -/* Symbol export - * ============= - * When building a shared library it is almost always necessary to tell - * the compiler which symbols to export. The png.h macro 'PNG_EXPORT' - * is used to mark the symbols. On some systems these symbols can be - * extracted at link time and need no special processing by the compiler, - * on other systems the symbols are flagged by the compiler and just - * the declaration requires a special tag applied (unfortunately) in a - * compiler dependent way. Some systems can do either. - * - * A small number of older systems also require a symbol from a DLL to - * be flagged to the program that calls it. This is a problem because - * we do not know in the header file included by application code that - * the symbol will come from a shared library, as opposed to a statically - * linked one. For this reason the application must tell us by setting - * the magic flag PNG_USE_DLL to turn on the special processing before - * it includes png.h. - * - * Four additional macros are used to make this happen: - * - * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from - * the build or imported if PNG_USE_DLL is set - compiler - * and system specific. - * - * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to - * 'type', compiler specific. - * - * PNG_DLL_EXPORT Set to the magic to use during a libpng build to - * make a symbol exported from the DLL. Not used in the - * public header files; see pngpriv.h for how it is used - * in the libpng build. - * - * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come - * from a DLL - used to define PNG_IMPEXP when - * PNG_USE_DLL is set. - */ - -/* System specific discovery. - * ========================== - * This code is used at build time to find PNG_IMPEXP, the API settings - * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL - * import processing is possible. On Windows systems it also sets - * compiler-specific macros to the values required to change the calling - * conventions of the various functions. - */ -#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\ - defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) - /* Windows system (DOS doesn't support DLLs). Includes builds under Cygwin or - * MinGW on any architecture currently supported by Windows. Also includes - * Watcom builds but these need special treatment because they are not - * compatible with GCC or Visual C because of different calling conventions. - */ -# if PNG_API_RULE == 2 - /* If this line results in an error, either because __watcall is not - * understood or because of a redefine just below you cannot use *this* - * build of the library with the compiler you are using. *This* build was - * build using Watcom and applications must also be built using Watcom! - */ -# define PNGCAPI __watcall -# endif - -# if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800)) -# define PNGCAPI __cdecl -# if PNG_API_RULE == 1 - /* If this line results in an error __stdcall is not understood and - * PNG_API_RULE should not have been set to '1'. - */ -# define PNGAPI __stdcall -# endif -# else - /* An older compiler, or one not detected (erroneously) above, - * if necessary override on the command line to get the correct - * variants for the compiler. - */ -# ifndef PNGCAPI -# define PNGCAPI _cdecl -# endif -# if PNG_API_RULE == 1 && !defined(PNGAPI) -# define PNGAPI _stdcall -# endif -# endif /* compiler/api */ - - /* NOTE: PNGCBAPI always defaults to PNGCAPI. */ - -# if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD) -# error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed" -# endif - -# if (defined(_MSC_VER) && _MSC_VER < 800) ||\ - (defined(__BORLANDC__) && __BORLANDC__ < 0x500) - /* older Borland and MSC - * compilers used '__export' and required this to be after - * the type. - */ -# ifndef PNG_EXPORT_TYPE -# define PNG_EXPORT_TYPE(type) type PNG_IMPEXP -# endif -# define PNG_DLL_EXPORT __export -# else /* newer compiler */ -# define PNG_DLL_EXPORT __declspec(dllexport) -# ifndef PNG_DLL_IMPORT -# define PNG_DLL_IMPORT __declspec(dllimport) -# endif -# endif /* compiler */ - -#else /* !Windows */ -# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__) -# define PNGAPI _System -# else /* !Windows/x86 && !OS/2 */ - /* Use the defaults, or define PNG*API on the command line (but - * this will have to be done for every compile!) - */ -# endif /* other system, !OS/2 */ -#endif /* !Windows/x86 */ - -/* Now do all the defaulting . */ -#ifndef PNGCAPI -# define PNGCAPI -#endif -#ifndef PNGCBAPI -# define PNGCBAPI PNGCAPI -#endif -#ifndef PNGAPI -# define PNGAPI PNGCAPI -#endif - -/* PNG_IMPEXP may be set on the compilation system command line or (if not set) - * then in an internal header file when building the library, otherwise (when - * using the library) it is set here. - */ -#ifndef PNG_IMPEXP -# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT) - /* This forces use of a DLL, disallowing static linking */ -# define PNG_IMPEXP PNG_DLL_IMPORT -# endif - -# ifndef PNG_IMPEXP -# define PNG_IMPEXP -# endif -#endif - -/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat - * 'attributes' as a storage class - the attributes go at the start of the - * function definition, and attributes are always appended regardless of the - * compiler. This considerably simplifies these macros but may cause problems - * if any compilers both need function attributes and fail to handle them as - * a storage class (this is unlikely.) - */ -#ifndef PNG_FUNCTION -# define PNG_FUNCTION(type, name, args, attributes) attributes type name args -#endif - -#ifndef PNG_EXPORT_TYPE -# define PNG_EXPORT_TYPE(type) PNG_IMPEXP type -#endif - - /* The ordinal value is only relevant when preprocessing png.h for symbol - * table entries, so we discard it here. See the .dfn files in the - * scripts directory. - */ - -#ifndef PNG_EXPORTA -# define PNG_EXPORTA(ordinal, type, name, args, attributes) \ - PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), PNGARG(args), \ - PNG_LINKAGE_API attributes) -#endif - -/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument, - * so make something non-empty to satisfy the requirement: - */ -#define PNG_EMPTY /*empty list*/ - -#define PNG_EXPORT(ordinal, type, name, args) \ - PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY) - -/* Use PNG_REMOVED to comment out a removed interface. */ -#ifndef PNG_REMOVED -# define PNG_REMOVED(ordinal, type, name, args, attributes) -#endif - -#ifndef PNG_CALLBACK -# define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args) -#endif - -/* Support for compiler specific function attributes. These are used - * so that where compiler support is available incorrect use of API - * functions in png.h will generate compiler warnings. - * - * Added at libpng-1.2.41. - */ - -#ifndef PNG_NO_PEDANTIC_WARNINGS -# ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED -# define PNG_PEDANTIC_WARNINGS_SUPPORTED -# endif -#endif - -#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED - /* Support for compiler specific function attributes. These are used - * so that where compiler support is available, incorrect use of API - * functions in png.h will generate compiler warnings. Added at libpng - * version 1.2.41. Disabling these removes the warnings but may also produce - * less efficient code. - */ -# if defined(__clang__) && defined(__has_attribute) - /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */ -# if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__) -# define PNG_USE_RESULT __attribute__((__warn_unused_result__)) -# endif -# if !defined(PNG_NORETURN) && __has_attribute(__noreturn__) -# define PNG_NORETURN __attribute__((__noreturn__)) -# endif -# if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__) -# define PNG_ALLOCATED __attribute__((__malloc__)) -# endif -# if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__) -# define PNG_DEPRECATED __attribute__((__deprecated__)) -# endif -# if !defined(PNG_PRIVATE) -# ifdef __has_extension -# if __has_extension(attribute_unavailable_with_message) -# define PNG_PRIVATE __attribute__((__unavailable__(\ - "This function is not exported by libpng."))) -# endif -# endif -# endif -# ifndef PNG_RESTRICT -# define PNG_RESTRICT __restrict -# endif - -# elif defined(__GNUC__) -# ifndef PNG_USE_RESULT -# define PNG_USE_RESULT __attribute__((__warn_unused_result__)) -# endif -# ifndef PNG_NORETURN -# define PNG_NORETURN __attribute__((__noreturn__)) -# endif -# if __GNUC__ >= 3 -# ifndef PNG_ALLOCATED -# define PNG_ALLOCATED __attribute__((__malloc__)) -# endif -# ifndef PNG_DEPRECATED -# define PNG_DEPRECATED __attribute__((__deprecated__)) -# endif -# ifndef PNG_PRIVATE -# if 0 /* Doesn't work so we use deprecated instead*/ -# define PNG_PRIVATE \ - __attribute__((warning("This function is not exported by libpng."))) -# else -# define PNG_PRIVATE \ - __attribute__((__deprecated__)) -# endif -# endif -# if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1)) -# ifndef PNG_RESTRICT -# define PNG_RESTRICT __restrict -# endif -# endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */ -# endif /* __GNUC__ >= 3 */ - -# elif defined(_MSC_VER) && (_MSC_VER >= 1300) -# ifndef PNG_USE_RESULT -# define PNG_USE_RESULT /* not supported */ -# endif -# ifndef PNG_NORETURN -# define PNG_NORETURN __declspec(noreturn) -# endif -# ifndef PNG_ALLOCATED -# if (_MSC_VER >= 1400) -# define PNG_ALLOCATED __declspec(restrict) -# endif -# endif -# ifndef PNG_DEPRECATED -# define PNG_DEPRECATED __declspec(deprecated) -# endif -# ifndef PNG_PRIVATE -# define PNG_PRIVATE __declspec(deprecated) -# endif -# ifndef PNG_RESTRICT -# if (_MSC_VER >= 1400) -# define PNG_RESTRICT __restrict -# endif -# endif - -# elif defined(__WATCOMC__) -# ifndef PNG_RESTRICT -# define PNG_RESTRICT __restrict -# endif -# endif -#endif /* PNG_PEDANTIC_WARNINGS */ - -#ifndef PNG_DEPRECATED -# define PNG_DEPRECATED /* Use of this function is deprecated */ -#endif -#ifndef PNG_USE_RESULT -# define PNG_USE_RESULT /* The result of this function must be checked */ -#endif -#ifndef PNG_NORETURN -# define PNG_NORETURN /* This function does not return */ -#endif -#ifndef PNG_ALLOCATED -# define PNG_ALLOCATED /* The result of the function is new memory */ -#endif -#ifndef PNG_PRIVATE -# define PNG_PRIVATE /* This is a private libpng function */ -#endif -#ifndef PNG_RESTRICT -# define PNG_RESTRICT /* The C99 "restrict" feature */ -#endif - -#ifndef PNG_FP_EXPORT /* A floating point API. */ -# ifdef PNG_FLOATING_POINT_SUPPORTED -# define PNG_FP_EXPORT(ordinal, type, name, args)\ - PNG_EXPORT(ordinal, type, name, args); -# else /* No floating point APIs */ -# define PNG_FP_EXPORT(ordinal, type, name, args) -# endif -#endif -#ifndef PNG_FIXED_EXPORT /* A fixed point API. */ -# ifdef PNG_FIXED_POINT_SUPPORTED -# define PNG_FIXED_EXPORT(ordinal, type, name, args)\ - PNG_EXPORT(ordinal, type, name, args); -# else /* No fixed point APIs */ -# define PNG_FIXED_EXPORT(ordinal, type, name, args) -# endif -#endif - -#ifndef PNG_BUILDING_SYMBOL_TABLE -/* Some typedefs to get us started. These should be safe on most of the common - * platforms. - * - * png_uint_32 and png_int_32 may, currently, be larger than required to hold a - * 32-bit value however this is not normally advisable. - * - * png_uint_16 and png_int_16 should always be two bytes in size - this is - * verified at library build time. - * - * png_byte must always be one byte in size. - * - * The checks below use constants from limits.h, as defined by the ISOC90 - * standard. - */ -#if CHAR_BIT == 8 && UCHAR_MAX == 255 - typedef unsigned char png_byte; -#else -# error "libpng requires 8-bit bytes" -#endif - -#if INT_MIN == -32768 && INT_MAX == 32767 - typedef int png_int_16; -#elif SHRT_MIN == -32768 && SHRT_MAX == 32767 - typedef short png_int_16; -#else -# error "libpng requires a signed 16-bit type" -#endif - -#if UINT_MAX == 65535 - typedef unsigned int png_uint_16; -#elif USHRT_MAX == 65535 - typedef unsigned short png_uint_16; -#else -# error "libpng requires an unsigned 16-bit type" -#endif - -#if INT_MIN < -2147483646 && INT_MAX > 2147483646 - typedef int png_int_32; -#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646 - typedef long int png_int_32; -#else -# error "libpng requires a signed 32-bit (or more) type" -#endif - -#if UINT_MAX > 4294967294 - typedef unsigned int png_uint_32; -#elif ULONG_MAX > 4294967294 - typedef unsigned long int png_uint_32; -#else -# error "libpng requires an unsigned 32-bit (or more) type" -#endif - -/* Prior to 1.6.0 it was possible to disable the use of size_t, 1.6.0, however, - * requires an ISOC90 compiler and relies on consistent behavior of sizeof. - */ -typedef size_t png_size_t; -typedef ptrdiff_t png_ptrdiff_t; - -/* libpng needs to know the maximum value of 'size_t' and this controls the - * definition of png_alloc_size_t, below. This maximum value of size_t limits - * but does not control the maximum allocations the library makes - there is - * direct application control of this through png_set_user_limits(). - */ -#ifndef PNG_SMALL_SIZE_T - /* Compiler specific tests for systems where size_t is known to be less than - * 32 bits (some of these systems may no longer work because of the lack of - * 'far' support; see above.) - */ -# if (defined(__TURBOC__) && !defined(__FLAT__)) ||\ - (defined(_MSC_VER) && defined(MAXSEG_64K)) -# define PNG_SMALL_SIZE_T -# endif -#endif - -/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, and no - * smaller than png_uint_32. Casts from png_size_t or png_uint_32 to - * png_alloc_size_t are not necessary; in fact, it is recommended not to use - * them at all so that the compiler can complain when something turns out to be - * problematic. - * - * Casts in the other direction (from png_alloc_size_t to png_size_t or - * png_uint_32) should be explicitly applied; however, we do not expect to - * encounter practical situations that require such conversions. - * - * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than - * 4294967295 - i.e. less than the maximum value of png_uint_32. - */ -#ifdef PNG_SMALL_SIZE_T - typedef png_uint_32 png_alloc_size_t; -#else - typedef png_size_t png_alloc_size_t; -#endif - -/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler - * implementations of Intel CPU specific support of user-mode segmented address - * spaces, where 16-bit pointers address more than 65536 bytes of memory using - * separate 'segment' registers. The implementation requires two different - * types of pointer (only one of which includes the segment value.) - * - * If required this support is available in version 1.2 of libpng and may be - * available in versions through 1.5, although the correctness of the code has - * not been verified recently. - */ - -/* Typedef for floating-point numbers that are converted to fixed-point with a - * multiple of 100,000, e.g., gamma - */ -typedef png_int_32 png_fixed_point; - -/* Add typedefs for pointers */ -typedef void * png_voidp; -typedef const void * png_const_voidp; -typedef png_byte * png_bytep; -typedef const png_byte * png_const_bytep; -typedef png_uint_32 * png_uint_32p; -typedef const png_uint_32 * png_const_uint_32p; -typedef png_int_32 * png_int_32p; -typedef const png_int_32 * png_const_int_32p; -typedef png_uint_16 * png_uint_16p; -typedef const png_uint_16 * png_const_uint_16p; -typedef png_int_16 * png_int_16p; -typedef const png_int_16 * png_const_int_16p; -typedef char * png_charp; -typedef const char * png_const_charp; -typedef png_fixed_point * png_fixed_point_p; -typedef const png_fixed_point * png_const_fixed_point_p; -typedef png_size_t * png_size_tp; -typedef const png_size_t * png_const_size_tp; - -#ifdef PNG_STDIO_SUPPORTED -typedef FILE * png_FILE_p; -#endif - -#ifdef PNG_FLOATING_POINT_SUPPORTED -typedef double * png_doublep; -typedef const double * png_const_doublep; -#endif - -/* Pointers to pointers; i.e. arrays */ -typedef png_byte * * png_bytepp; -typedef png_uint_32 * * png_uint_32pp; -typedef png_int_32 * * png_int_32pp; -typedef png_uint_16 * * png_uint_16pp; -typedef png_int_16 * * png_int_16pp; -typedef const char * * png_const_charpp; -typedef char * * png_charpp; -typedef png_fixed_point * * png_fixed_point_pp; -#ifdef PNG_FLOATING_POINT_SUPPORTED -typedef double * * png_doublepp; -#endif - -/* Pointers to pointers to pointers; i.e., pointer to array */ -typedef char * * * png_charppp; - -#endif /* PNG_BUILDING_SYMBOL_TABLE */ - -#endif /* PNGCONF_H */ diff --git a/third_party/libpng/pngdebug.h b/third_party/libpng/pngdebug.h deleted file mode 100644 index 15a7ed0c95..0000000000 --- a/third_party/libpng/pngdebug.h +++ /dev/null @@ -1,153 +0,0 @@ - -/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c - * - * Last changed in libpng 1.6.8 [December 19, 2013] - * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -/* Define PNG_DEBUG at compile time for debugging information. Higher - * numbers for PNG_DEBUG mean more debugging information. This has - * only been added since version 0.95 so it is not implemented throughout - * libpng yet, but more support will be added as needed. - * - * png_debug[1-2]?(level, message ,arg{0-2}) - * Expands to a statement (either a simple expression or a compound - * do..while(0) statement) that outputs a message with parameter - * substitution if PNG_DEBUG is defined to 2 or more. If PNG_DEBUG - * is undefined, 0 or 1 every png_debug expands to a simple expression - * (actually ((void)0)). - * - * level: level of detail of message, starting at 0. A level 'n' - * message is preceded by 'n' 3-space indentations (not implemented - * on Microsoft compilers unless PNG_DEBUG_FILE is also - * defined, to allow debug DLL compilation with no standard IO). - * message: a printf(3) style text string. A trailing '\n' is added - * to the message. - * arg: 0 to 2 arguments for printf(3) style substitution in message. - */ -#ifndef PNGDEBUG_H -#define PNGDEBUG_H -/* These settings control the formatting of messages in png.c and pngerror.c */ -/* Moved to pngdebug.h at 1.5.0 */ -# ifndef PNG_LITERAL_SHARP -# define PNG_LITERAL_SHARP 0x23 -# endif -# ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET -# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b -# endif -# ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET -# define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d -# endif -# ifndef PNG_STRING_NEWLINE -# define PNG_STRING_NEWLINE "\n" -# endif - -#ifdef PNG_DEBUG -# if (PNG_DEBUG > 0) -# if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER) -# include <crtdbg.h> -# if (PNG_DEBUG > 1) -# ifndef _DEBUG -# define _DEBUG -# endif -# ifndef png_debug -# define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE) -# endif -# ifndef png_debug1 -# define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1) -# endif -# ifndef png_debug2 -# define png_debug2(l,m,p1,p2) \ - _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2) -# endif -# endif -# else /* PNG_DEBUG_FILE || !_MSC_VER */ -# ifndef PNG_STDIO_SUPPORTED -# include <stdio.h> /* not included yet */ -# endif -# ifndef PNG_DEBUG_FILE -# define PNG_DEBUG_FILE stderr -# endif /* PNG_DEBUG_FILE */ - -# if (PNG_DEBUG > 1) -# ifdef __STDC__ -# ifndef png_debug -# define png_debug(l,m) \ - do { \ - int num_tabs=l; \ - fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ - (num_tabs==2 ? " " : (num_tabs>2 ? " " : "")))); \ - } while (0) -# endif -# ifndef png_debug1 -# define png_debug1(l,m,p1) \ - do { \ - int num_tabs=l; \ - fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ - (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1); \ - } while (0) -# endif -# ifndef png_debug2 -# define png_debug2(l,m,p1,p2) \ - do { \ - int num_tabs=l; \ - fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ - (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1,p2);\ - } while (0) -# endif -# else /* __STDC __ */ -# ifndef png_debug -# define png_debug(l,m) \ - do { \ - int num_tabs=l; \ - char format[256]; \ - snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ - (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ - m,PNG_STRING_NEWLINE); \ - fprintf(PNG_DEBUG_FILE,format); \ - } while (0) -# endif -# ifndef png_debug1 -# define png_debug1(l,m,p1) \ - do { \ - int num_tabs=l; \ - char format[256]; \ - snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ - (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ - m,PNG_STRING_NEWLINE); \ - fprintf(PNG_DEBUG_FILE,format,p1); \ - } while (0) -# endif -# ifndef png_debug2 -# define png_debug2(l,m,p1,p2) \ - do { \ - int num_tabs=l; \ - char format[256]; \ - snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ - (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ - m,PNG_STRING_NEWLINE); \ - fprintf(PNG_DEBUG_FILE,format,p1,p2); \ - } while (0) -# endif -# endif /* __STDC __ */ -# endif /* (PNG_DEBUG > 1) */ - -# endif /* _MSC_VER */ -# endif /* (PNG_DEBUG > 0) */ -#endif /* PNG_DEBUG */ -#ifndef png_debug -# define png_debug(l, m) ((void)0) -#endif -#ifndef png_debug1 -# define png_debug1(l, m, p1) ((void)0) -#endif -#ifndef png_debug2 -# define png_debug2(l, m, p1, p2) ((void)0) -#endif -#endif /* PNGDEBUG_H */ diff --git a/third_party/libpng/pngerror.c b/third_party/libpng/pngerror.c deleted file mode 100644 index 6904bea1a2..0000000000 --- a/third_party/libpng/pngerror.c +++ /dev/null @@ -1,963 +0,0 @@ - -/* pngerror.c - stub functions for i/o and memory allocation - * - * Last changed in libpng 1.6.15 [November 20, 2014] - * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This file provides a location for all error handling. Users who - * need special error handling are expected to write replacement functions - * and use png_set_error_fn() to use those functions. See the instructions - * at each function. - */ - -#include "pngpriv.h" - -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) - -static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr, - png_const_charp error_message)),PNG_NORETURN); - -#ifdef PNG_WARNINGS_SUPPORTED -static void /* PRIVATE */ -png_default_warning PNGARG((png_const_structrp png_ptr, - png_const_charp warning_message)); -#endif /* WARNINGS */ - -/* This function is called whenever there is a fatal error. This function - * should not be changed. If there is a need to handle errors differently, - * you should supply a replacement error function and use png_set_error_fn() - * to replace the error function at run-time. - */ -#ifdef PNG_ERROR_TEXT_SUPPORTED -PNG_FUNCTION(void,PNGAPI -png_error,(png_const_structrp png_ptr, png_const_charp error_message), - PNG_NORETURN) -{ -#ifdef PNG_ERROR_NUMBERS_SUPPORTED - char msg[16]; - if (png_ptr != NULL) - { - if ((png_ptr->flags & - (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0 - { - if (*error_message == PNG_LITERAL_SHARP) - { - /* Strip "#nnnn " from beginning of error message. */ - int offset; - for (offset = 1; offset<15; offset++) - if (error_message[offset] == ' ') - break; - - if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) - { - int i; - for (i = 0; i < offset - 1; i++) - msg[i] = error_message[i + 1]; - msg[i - 1] = '\0'; - error_message = msg; - } - - else - error_message += offset; - } - - else - { - if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) - { - msg[0] = '0'; - msg[1] = '\0'; - error_message = msg; - } - } - } - } -#endif - if (png_ptr != NULL && png_ptr->error_fn != NULL) - (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), - error_message); - - /* If the custom handler doesn't exist, or if it returns, - use the default handler, which will not return. */ - png_default_error(png_ptr, error_message); -} -#else -PNG_FUNCTION(void,PNGAPI -png_err,(png_const_structrp png_ptr),PNG_NORETURN) -{ - /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed - * erroneously as '\0', instead of the empty string "". This was - * apparently an error, introduced in libpng-1.2.20, and png_default_error - * will crash in this case. - */ - if (png_ptr != NULL && png_ptr->error_fn != NULL) - (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), ""); - - /* If the custom handler doesn't exist, or if it returns, - use the default handler, which will not return. */ - png_default_error(png_ptr, ""); -} -#endif /* ERROR_TEXT */ - -/* Utility to safely appends strings to a buffer. This never errors out so - * error checking is not required in the caller. - */ -size_t -png_safecat(png_charp buffer, size_t bufsize, size_t pos, - png_const_charp string) -{ - if (buffer != NULL && pos < bufsize) - { - if (string != NULL) - while (*string != '\0' && pos < bufsize-1) - buffer[pos++] = *string++; - - buffer[pos] = '\0'; - } - - return pos; -} - -#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) -/* Utility to dump an unsigned value into a buffer, given a start pointer and - * and end pointer (which should point just *beyond* the end of the buffer!) - * Returns the pointer to the start of the formatted string. - */ -png_charp -png_format_number(png_const_charp start, png_charp end, int format, - png_alloc_size_t number) -{ - int count = 0; /* number of digits output */ - int mincount = 1; /* minimum number required */ - int output = 0; /* digit output (for the fixed point format) */ - - *--end = '\0'; - - /* This is written so that the loop always runs at least once, even with - * number zero. - */ - while (end > start && (number != 0 || count < mincount)) - { - - static const char digits[] = "0123456789ABCDEF"; - - switch (format) - { - case PNG_NUMBER_FORMAT_fixed: - /* Needs five digits (the fraction) */ - mincount = 5; - if (output != 0 || number % 10 != 0) - { - *--end = digits[number % 10]; - output = 1; - } - number /= 10; - break; - - case PNG_NUMBER_FORMAT_02u: - /* Expects at least 2 digits. */ - mincount = 2; - /* FALL THROUGH */ - - case PNG_NUMBER_FORMAT_u: - *--end = digits[number % 10]; - number /= 10; - break; - - case PNG_NUMBER_FORMAT_02x: - /* This format expects at least two digits */ - mincount = 2; - /* FALL THROUGH */ - - case PNG_NUMBER_FORMAT_x: - *--end = digits[number & 0xf]; - number >>= 4; - break; - - default: /* an error */ - number = 0; - break; - } - - /* Keep track of the number of digits added */ - ++count; - - /* Float a fixed number here: */ - if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start)) - { - /* End of the fraction, but maybe nothing was output? In that case - * drop the decimal point. If the number is a true zero handle that - * here. - */ - if (output != 0) - *--end = '.'; - else if (number == 0) /* and !output */ - *--end = '0'; - } - } - - return end; -} -#endif - -#ifdef PNG_WARNINGS_SUPPORTED -/* This function is called whenever there is a non-fatal error. This function - * should not be changed. If there is a need to handle warnings differently, - * you should supply a replacement warning function and use - * png_set_error_fn() to replace the warning function at run-time. - */ -void PNGAPI -png_warning(png_const_structrp png_ptr, png_const_charp warning_message) -{ - int offset = 0; - if (png_ptr != NULL) - { -#ifdef PNG_ERROR_NUMBERS_SUPPORTED - if ((png_ptr->flags & - (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0) -#endif - { - if (*warning_message == PNG_LITERAL_SHARP) - { - for (offset = 1; offset < 15; offset++) - if (warning_message[offset] == ' ') - break; - } - } - } - if (png_ptr != NULL && png_ptr->warning_fn != NULL) - (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr), - warning_message + offset); - else - png_default_warning(png_ptr, warning_message + offset); -} - -/* These functions support 'formatted' warning messages with up to - * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter - * is introduced by @<number>, where 'number' starts at 1. This follows the - * standard established by X/Open for internationalizable error messages. - */ -void -png_warning_parameter(png_warning_parameters p, int number, - png_const_charp string) -{ - if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT) - (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string); -} - -void -png_warning_parameter_unsigned(png_warning_parameters p, int number, int format, - png_alloc_size_t value) -{ - char buffer[PNG_NUMBER_BUFFER_SIZE]; - png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value)); -} - -void -png_warning_parameter_signed(png_warning_parameters p, int number, int format, - png_int_32 value) -{ - png_alloc_size_t u; - png_charp str; - char buffer[PNG_NUMBER_BUFFER_SIZE]; - - /* Avoid overflow by doing the negate in a png_alloc_size_t: */ - u = (png_alloc_size_t)value; - if (value < 0) - u = ~u + 1; - - str = PNG_FORMAT_NUMBER(buffer, format, u); - - if (value < 0 && str > buffer) - *--str = '-'; - - png_warning_parameter(p, number, str); -} - -void -png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p, - png_const_charp message) -{ - /* The internal buffer is just 192 bytes - enough for all our messages, - * overflow doesn't happen because this code checks! If someone figures - * out how to send us a message longer than 192 bytes, all that will - * happen is that the message will be truncated appropriately. - */ - size_t i = 0; /* Index in the msg[] buffer: */ - char msg[192]; - - /* Each iteration through the following loop writes at most one character - * to msg[i++] then returns here to validate that there is still space for - * the trailing '\0'. It may (in the case of a parameter) read more than - * one character from message[]; it must check for '\0' and continue to the - * test if it finds the end of string. - */ - while (i<(sizeof msg)-1 && *message != '\0') - { - /* '@' at end of string is now just printed (previously it was skipped); - * it is an error in the calling code to terminate the string with @. - */ - if (p != NULL && *message == '@' && message[1] != '\0') - { - int parameter_char = *++message; /* Consume the '@' */ - static const char valid_parameters[] = "123456789"; - int parameter = 0; - - /* Search for the parameter digit, the index in the string is the - * parameter to use. - */ - while (valid_parameters[parameter] != parameter_char && - valid_parameters[parameter] != '\0') - ++parameter; - - /* If the parameter digit is out of range it will just get printed. */ - if (parameter < PNG_WARNING_PARAMETER_COUNT) - { - /* Append this parameter */ - png_const_charp parm = p[parameter]; - png_const_charp pend = p[parameter] + (sizeof p[parameter]); - - /* No need to copy the trailing '\0' here, but there is no guarantee - * that parm[] has been initialized, so there is no guarantee of a - * trailing '\0': - */ - while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend) - msg[i++] = *parm++; - - /* Consume the parameter digit too: */ - ++message; - continue; - } - - /* else not a parameter and there is a character after the @ sign; just - * copy that. This is known not to be '\0' because of the test above. - */ - } - - /* At this point *message can't be '\0', even in the bad parameter case - * above where there is a lone '@' at the end of the message string. - */ - msg[i++] = *message++; - } - - /* i is always less than (sizeof msg), so: */ - msg[i] = '\0'; - - /* And this is the formatted message. It may be larger than - * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these - * are not (currently) formatted. - */ - png_warning(png_ptr, msg); -} -#endif /* WARNINGS */ - -#ifdef PNG_BENIGN_ERRORS_SUPPORTED -void PNGAPI -png_benign_error(png_const_structrp png_ptr, png_const_charp error_message) -{ - if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) - { -# ifdef PNG_READ_SUPPORTED - if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && - png_ptr->chunk_name != 0) - png_chunk_warning(png_ptr, error_message); - else -# endif - png_warning(png_ptr, error_message); - } - - else - { -# ifdef PNG_READ_SUPPORTED - if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && - png_ptr->chunk_name != 0) - png_chunk_error(png_ptr, error_message); - else -# endif - png_error(png_ptr, error_message); - } - -# ifndef PNG_ERROR_TEXT_SUPPORTED - PNG_UNUSED(error_message) -# endif -} - -void /* PRIVATE */ -png_app_warning(png_const_structrp png_ptr, png_const_charp error_message) -{ - if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0) - png_warning(png_ptr, error_message); - else - png_error(png_ptr, error_message); - -# ifndef PNG_ERROR_TEXT_SUPPORTED - PNG_UNUSED(error_message) -# endif -} - -void /* PRIVATE */ -png_app_error(png_const_structrp png_ptr, png_const_charp error_message) -{ - if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0) - png_warning(png_ptr, error_message); - else - png_error(png_ptr, error_message); - -# ifndef PNG_ERROR_TEXT_SUPPORTED - PNG_UNUSED(error_message) -# endif -} -#endif /* BENIGN_ERRORS */ - -#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */ -#if defined(PNG_WARNINGS_SUPPORTED) || \ - (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)) -/* These utilities are used internally to build an error message that relates - * to the current chunk. The chunk name comes from png_ptr->chunk_name, - * which is used to prefix the message. The message is limited in length - * to 63 bytes. The name characters are output as hex digits wrapped in [] - * if the character is invalid. - */ -#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) -static PNG_CONST char png_digit[16] = { - '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', - 'A', 'B', 'C', 'D', 'E', 'F' -}; - -static void /* PRIVATE */ -png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp - error_message) -{ - png_uint_32 chunk_name = png_ptr->chunk_name; - int iout = 0, ishift = 24; - - while (ishift >= 0) - { - int c = (int)(chunk_name >> ishift) & 0xff; - - ishift -= 8; - if (isnonalpha(c) != 0) - { - buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET; - buffer[iout++] = png_digit[(c & 0xf0) >> 4]; - buffer[iout++] = png_digit[c & 0x0f]; - buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET; - } - - else - { - buffer[iout++] = (char)c; - } - } - - if (error_message == NULL) - buffer[iout] = '\0'; - - else - { - int iin = 0; - - buffer[iout++] = ':'; - buffer[iout++] = ' '; - - while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0') - buffer[iout++] = error_message[iin++]; - - /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */ - buffer[iout] = '\0'; - } -} -#endif /* WARNINGS || ERROR_TEXT */ - -#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) -PNG_FUNCTION(void,PNGAPI -png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message), - PNG_NORETURN) -{ - char msg[18+PNG_MAX_ERROR_TEXT]; - if (png_ptr == NULL) - png_error(png_ptr, error_message); - - else - { - png_format_buffer(png_ptr, msg, error_message); - png_error(png_ptr, msg); - } -} -#endif /* READ && ERROR_TEXT */ - -#ifdef PNG_WARNINGS_SUPPORTED -void PNGAPI -png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message) -{ - char msg[18+PNG_MAX_ERROR_TEXT]; - if (png_ptr == NULL) - png_warning(png_ptr, warning_message); - - else - { - png_format_buffer(png_ptr, msg, warning_message); - png_warning(png_ptr, msg); - } -} -#endif /* WARNINGS */ - -#ifdef PNG_READ_SUPPORTED -#ifdef PNG_BENIGN_ERRORS_SUPPORTED -void PNGAPI -png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp - error_message) -{ - if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) - png_chunk_warning(png_ptr, error_message); - - else - png_chunk_error(png_ptr, error_message); - -# ifndef PNG_ERROR_TEXT_SUPPORTED - PNG_UNUSED(error_message) -# endif -} -#endif -#endif /* READ */ - -void /* PRIVATE */ -png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error) -{ -# ifndef PNG_WARNINGS_SUPPORTED - PNG_UNUSED(message) -# endif - - /* This is always supported, but for just read or just write it - * unconditionally does the right thing. - */ -# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) - if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) -# endif - -# ifdef PNG_READ_SUPPORTED - { - if (error < PNG_CHUNK_ERROR) - png_chunk_warning(png_ptr, message); - - else - png_chunk_benign_error(png_ptr, message); - } -# endif - -# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) - else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) -# endif - -# ifdef PNG_WRITE_SUPPORTED - { - if (error < PNG_CHUNK_WRITE_ERROR) - png_app_warning(png_ptr, message); - - else - png_app_error(png_ptr, message); - } -# endif -} - -#ifdef PNG_ERROR_TEXT_SUPPORTED -#ifdef PNG_FLOATING_POINT_SUPPORTED -PNG_FUNCTION(void, -png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN) -{ -# define fixed_message "fixed point overflow in " -# define fixed_message_ln ((sizeof fixed_message)-1) - int iin; - char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT]; - memcpy(msg, fixed_message, fixed_message_ln); - iin = 0; - if (name != NULL) - while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0) - { - msg[fixed_message_ln + iin] = name[iin]; - ++iin; - } - msg[fixed_message_ln + iin] = 0; - png_error(png_ptr, msg); -} -#endif -#endif - -#ifdef PNG_SETJMP_SUPPORTED -/* This API only exists if ANSI-C style error handling is used, - * otherwise it is necessary for png_default_error to be overridden. - */ -jmp_buf* PNGAPI -png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn, - size_t jmp_buf_size) -{ - /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value - * and it must not change after that. Libpng doesn't care how big the - * buffer is, just that it doesn't change. - * - * If the buffer size is no *larger* than the size of jmp_buf when libpng is - * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0 - * semantics that this call will not fail. If the size is larger, however, - * the buffer is allocated and this may fail, causing the function to return - * NULL. - */ - if (png_ptr == NULL) - return NULL; - - if (png_ptr->jmp_buf_ptr == NULL) - { - png_ptr->jmp_buf_size = 0; /* not allocated */ - - if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local)) - png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; - - else - { - png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *, - png_malloc_warn(png_ptr, jmp_buf_size)); - - if (png_ptr->jmp_buf_ptr == NULL) - return NULL; /* new NULL return on OOM */ - - png_ptr->jmp_buf_size = jmp_buf_size; - } - } - - else /* Already allocated: check the size */ - { - size_t size = png_ptr->jmp_buf_size; - - if (size == 0) - { - size = (sizeof png_ptr->jmp_buf_local); - if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local) - { - /* This is an internal error in libpng: somehow we have been left - * with a stack allocated jmp_buf when the application regained - * control. It's always possible to fix this up, but for the moment - * this is a png_error because that makes it easy to detect. - */ - png_error(png_ptr, "Libpng jmp_buf still allocated"); - /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */ - } - } - - if (size != jmp_buf_size) - { - png_warning(png_ptr, "Application jmp_buf size changed"); - return NULL; /* caller will probably crash: no choice here */ - } - } - - /* Finally fill in the function, now we have a satisfactory buffer. It is - * valid to change the function on every call. - */ - png_ptr->longjmp_fn = longjmp_fn; - return png_ptr->jmp_buf_ptr; -} - -void /* PRIVATE */ -png_free_jmpbuf(png_structrp png_ptr) -{ - if (png_ptr != NULL) - { - jmp_buf *jb = png_ptr->jmp_buf_ptr; - - /* A size of 0 is used to indicate a local, stack, allocation of the - * pointer; used here and in png.c - */ - if (jb != NULL && png_ptr->jmp_buf_size > 0) - { - - /* This stuff is so that a failure to free the error control structure - * does not leave libpng in a state with no valid error handling: the - * free always succeeds, if there is an error it gets ignored. - */ - if (jb != &png_ptr->jmp_buf_local) - { - /* Make an internal, libpng, jmp_buf to return here */ - jmp_buf free_jmp_buf; - - if (!setjmp(free_jmp_buf)) - { - png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */ - png_ptr->jmp_buf_size = 0; /* stack allocation */ - png_ptr->longjmp_fn = longjmp; - png_free(png_ptr, jb); /* Return to setjmp on error */ - } - } - } - - /* *Always* cancel everything out: */ - png_ptr->jmp_buf_size = 0; - png_ptr->jmp_buf_ptr = NULL; - png_ptr->longjmp_fn = 0; - } -} -#endif - -/* This is the default error handling function. Note that replacements for - * this function MUST NOT RETURN, or the program will likely crash. This - * function is used by default, or if the program supplies NULL for the - * error function pointer in png_set_error_fn(). - */ -static PNG_FUNCTION(void /* PRIVATE */, -png_default_error,(png_const_structrp png_ptr, png_const_charp error_message), - PNG_NORETURN) -{ -#ifdef PNG_CONSOLE_IO_SUPPORTED -#ifdef PNG_ERROR_NUMBERS_SUPPORTED - /* Check on NULL only added in 1.5.4 */ - if (error_message != NULL && *error_message == PNG_LITERAL_SHARP) - { - /* Strip "#nnnn " from beginning of error message. */ - int offset; - char error_number[16]; - for (offset = 0; offset<15; offset++) - { - error_number[offset] = error_message[offset + 1]; - if (error_message[offset] == ' ') - break; - } - - if ((offset > 1) && (offset < 15)) - { - error_number[offset - 1] = '\0'; - fprintf(stderr, "libpng error no. %s: %s", - error_number, error_message + offset + 1); - fprintf(stderr, PNG_STRING_NEWLINE); - } - - else - { - fprintf(stderr, "libpng error: %s, offset=%d", - error_message, offset); - fprintf(stderr, PNG_STRING_NEWLINE); - } - } - else -#endif - { - fprintf(stderr, "libpng error: %s", error_message ? error_message : - "undefined"); - fprintf(stderr, PNG_STRING_NEWLINE); - } -#else - PNG_UNUSED(error_message) /* Make compiler happy */ -#endif - png_longjmp(png_ptr, 1); -} - -PNG_FUNCTION(void,PNGAPI -png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN) -{ -#ifdef PNG_SETJMP_SUPPORTED - if (png_ptr != NULL && png_ptr->longjmp_fn != NULL && - png_ptr->jmp_buf_ptr != NULL) - png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val); -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(val) -#endif - - /* If control reaches this point, png_longjmp() must not return. The only - * choice is to terminate the whole process (or maybe the thread); to do - * this the ANSI-C abort() function is used unless a different method is - * implemented by overriding the default configuration setting for - * PNG_ABORT(). - */ - PNG_ABORT(); -} - -#ifdef PNG_WARNINGS_SUPPORTED -/* This function is called when there is a warning, but the library thinks - * it can continue anyway. Replacement functions don't have to do anything - * here if you don't want them to. In the default configuration, png_ptr is - * not used, but it is passed in case it may be useful. - */ -static void /* PRIVATE */ -png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message) -{ -#ifdef PNG_CONSOLE_IO_SUPPORTED -# ifdef PNG_ERROR_NUMBERS_SUPPORTED - if (*warning_message == PNG_LITERAL_SHARP) - { - int offset; - char warning_number[16]; - for (offset = 0; offset < 15; offset++) - { - warning_number[offset] = warning_message[offset + 1]; - if (warning_message[offset] == ' ') - break; - } - - if ((offset > 1) && (offset < 15)) - { - warning_number[offset + 1] = '\0'; - fprintf(stderr, "libpng warning no. %s: %s", - warning_number, warning_message + offset); - fprintf(stderr, PNG_STRING_NEWLINE); - } - - else - { - fprintf(stderr, "libpng warning: %s", - warning_message); - fprintf(stderr, PNG_STRING_NEWLINE); - } - } - else -# endif - - { - fprintf(stderr, "libpng warning: %s", warning_message); - fprintf(stderr, PNG_STRING_NEWLINE); - } -#else - PNG_UNUSED(warning_message) /* Make compiler happy */ -#endif - PNG_UNUSED(png_ptr) /* Make compiler happy */ -} -#endif /* WARNINGS */ - -/* This function is called when the application wants to use another method - * of handling errors and warnings. Note that the error function MUST NOT - * return to the calling routine or serious problems will occur. The return - * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1) - */ -void PNGAPI -png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr, - png_error_ptr error_fn, png_error_ptr warning_fn) -{ - if (png_ptr == NULL) - return; - - png_ptr->error_ptr = error_ptr; - png_ptr->error_fn = error_fn; -#ifdef PNG_WARNINGS_SUPPORTED - png_ptr->warning_fn = warning_fn; -#else - PNG_UNUSED(warning_fn) -#endif -} - - -/* This function returns a pointer to the error_ptr associated with the user - * functions. The application should free any memory associated with this - * pointer before png_write_destroy and png_read_destroy are called. - */ -png_voidp PNGAPI -png_get_error_ptr(png_const_structrp png_ptr) -{ - if (png_ptr == NULL) - return NULL; - - return ((png_voidp)png_ptr->error_ptr); -} - - -#ifdef PNG_ERROR_NUMBERS_SUPPORTED -void PNGAPI -png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode) -{ - if (png_ptr != NULL) - { - png_ptr->flags &= - ((~(PNG_FLAG_STRIP_ERROR_NUMBERS | - PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode); - } -} -#endif - -#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ - defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) - /* Currently the above both depend on SETJMP_SUPPORTED, however it would be - * possible to implement without setjmp support just so long as there is some - * way to handle the error return here: - */ -PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI -png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message), - PNG_NORETURN) -{ - const png_const_structrp png_ptr = png_nonconst_ptr; - png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); - - /* An error is always logged here, overwriting anything (typically a warning) - * that is already there: - */ - if (image != NULL) - { - png_safecat(image->message, (sizeof image->message), 0, error_message); - image->warning_or_error |= PNG_IMAGE_ERROR; - - /* Retrieve the jmp_buf from within the png_control, making this work for - * C++ compilation too is pretty tricky: C++ wants a pointer to the first - * element of a jmp_buf, but C doesn't tell us the type of that. - */ - if (image->opaque != NULL && image->opaque->error_buf != NULL) - longjmp(png_control_jmp_buf(image->opaque), 1); - - /* Missing longjmp buffer, the following is to help debugging: */ - { - size_t pos = png_safecat(image->message, (sizeof image->message), 0, - "bad longjmp: "); - png_safecat(image->message, (sizeof image->message), pos, - error_message); - } - } - - /* Here on an internal programming error. */ - abort(); -} - -#ifdef PNG_WARNINGS_SUPPORTED -void /* PRIVATE */ PNGCBAPI -png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message) -{ - const png_const_structrp png_ptr = png_nonconst_ptr; - png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); - - /* A warning is only logged if there is no prior warning or error. */ - if (image->warning_or_error == 0) - { - png_safecat(image->message, (sizeof image->message), 0, warning_message); - image->warning_or_error |= PNG_IMAGE_WARNING; - } -} -#endif - -int /* PRIVATE */ -png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg) -{ - volatile png_imagep image = image_in; - volatile int result; - volatile png_voidp saved_error_buf; - jmp_buf safe_jmpbuf; - - /* Safely execute function(arg) with png_error returning to this function. */ - saved_error_buf = image->opaque->error_buf; - result = setjmp(safe_jmpbuf) == 0; - - if (result != 0) - { - - image->opaque->error_buf = safe_jmpbuf; - result = function(arg); - } - - image->opaque->error_buf = saved_error_buf; - - /* And do the cleanup prior to any failure return. */ - if (result == 0) - png_image_free(image); - - return result; -} -#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */ -#endif /* READ || WRITE */ diff --git a/third_party/libpng/pngget.c b/third_party/libpng/pngget.c deleted file mode 100644 index 14fc7be520..0000000000 --- a/third_party/libpng/pngget.c +++ /dev/null @@ -1,1219 +0,0 @@ - -/* pngget.c - retrieval of values from info struct - * - * Last changed in libpng 1.6.17 [March 26, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - */ - -#include "pngpriv.h" - -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) - -png_uint_32 PNGAPI -png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr, - png_uint_32 flag) -{ - if (png_ptr != NULL && info_ptr != NULL) - return(info_ptr->valid & flag); - - return(0); -} - -png_size_t PNGAPI -png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return(info_ptr->rowbytes); - - return(0); -} - -#ifdef PNG_INFO_IMAGE_SUPPORTED -png_bytepp PNGAPI -png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return(info_ptr->row_pointers); - - return(0); -} -#endif - -#ifdef PNG_EASY_ACCESS_SUPPORTED -/* Easy access to info, added in libpng-0.99 */ -png_uint_32 PNGAPI -png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return info_ptr->width; - - return (0); -} - -png_uint_32 PNGAPI -png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return info_ptr->height; - - return (0); -} - -png_byte PNGAPI -png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return info_ptr->bit_depth; - - return (0); -} - -png_byte PNGAPI -png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return info_ptr->color_type; - - return (0); -} - -png_byte PNGAPI -png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return info_ptr->filter_type; - - return (0); -} - -png_byte PNGAPI -png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return info_ptr->interlace_type; - - return (0); -} - -png_byte PNGAPI -png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return info_ptr->compression_type; - - return (0); -} - -png_uint_32 PNGAPI -png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp - info_ptr) -{ -#ifdef PNG_pHYs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_pHYs) != 0) - { - png_debug1(1, "in %s retrieval function", - "png_get_x_pixels_per_meter"); - - if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER) - return (info_ptr->x_pixels_per_unit); - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return (0); -} - -png_uint_32 PNGAPI -png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp - info_ptr) -{ -#ifdef PNG_pHYs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_pHYs) != 0) - { - png_debug1(1, "in %s retrieval function", - "png_get_y_pixels_per_meter"); - - if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER) - return (info_ptr->y_pixels_per_unit); - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return (0); -} - -png_uint_32 PNGAPI -png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ -#ifdef PNG_pHYs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_pHYs) != 0) - { - png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter"); - - if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER && - info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit) - return (info_ptr->x_pixels_per_unit); - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return (0); -} - -#ifdef PNG_FLOATING_POINT_SUPPORTED -float PNGAPI -png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp - info_ptr) -{ -#ifdef PNG_READ_pHYs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_pHYs) != 0) - { - png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio"); - - if (info_ptr->x_pixels_per_unit != 0) - return ((float)((float)info_ptr->y_pixels_per_unit - /(float)info_ptr->x_pixels_per_unit)); - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return ((float)0.0); -} -#endif - -#ifdef PNG_FIXED_POINT_SUPPORTED -png_fixed_point PNGAPI -png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr, - png_const_inforp info_ptr) -{ -#ifdef PNG_READ_pHYs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_pHYs) != 0 && - info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 && - info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX && - info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX) - { - png_fixed_point res; - - png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed"); - - /* The following casts work because a PNG 4 byte integer only has a valid - * range of 0..2^31-1; otherwise the cast might overflow. - */ - if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1, - (png_int_32)info_ptr->x_pixels_per_unit) != 0) - return res; - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return 0; -} -#endif - -png_int_32 PNGAPI -png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ -#ifdef PNG_oFFs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_oFFs) != 0) - { - png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns"); - - if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER) - return (info_ptr->x_offset); - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return (0); -} - -png_int_32 PNGAPI -png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ -#ifdef PNG_oFFs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_oFFs) != 0) - { - png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns"); - - if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER) - return (info_ptr->y_offset); - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return (0); -} - -png_int_32 PNGAPI -png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ -#ifdef PNG_oFFs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_oFFs) != 0) - { - png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels"); - - if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL) - return (info_ptr->x_offset); - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return (0); -} - -png_int_32 PNGAPI -png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ -#ifdef PNG_oFFs_SUPPORTED - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_oFFs) != 0) - { - png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels"); - - if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL) - return (info_ptr->y_offset); - } -#else - PNG_UNUSED(png_ptr) - PNG_UNUSED(info_ptr) -#endif - - return (0); -} - -#ifdef PNG_INCH_CONVERSIONS_SUPPORTED -static png_uint_32 -ppi_from_ppm(png_uint_32 ppm) -{ -#if 0 - /* The conversion is *(2.54/100), in binary (32 digits): - * .00000110100000001001110101001001 - */ - png_uint_32 t1001, t1101; - ppm >>= 1; /* .1 */ - t1001 = ppm + (ppm >> 3); /* .1001 */ - t1101 = t1001 + (ppm >> 1); /* .1101 */ - ppm >>= 20; /* .000000000000000000001 */ - t1101 += t1101 >> 15; /* .1101000000000001101 */ - t1001 >>= 11; /* .000000000001001 */ - t1001 += t1001 >> 12; /* .000000000001001000000001001 */ - ppm += t1001; /* .000000000001001000001001001 */ - ppm += t1101; /* .110100000001001110101001001 */ - return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */ -#else - /* The argument is a PNG unsigned integer, so it is not permitted - * to be bigger than 2^31. - */ - png_fixed_point result; - if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127, - 5000) != 0) - return result; - - /* Overflow. */ - return 0; -#endif -} - -png_uint_32 PNGAPI -png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr)); -} - -png_uint_32 PNGAPI -png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr)); -} - -png_uint_32 PNGAPI -png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr)); -} - -#ifdef PNG_FIXED_POINT_SUPPORTED -static png_fixed_point -png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns) -{ - /* Convert from metres * 1,000,000 to inches * 100,000, meters to - * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127. - * Notice that this can overflow - a warning is output and 0 is - * returned. - */ - return png_muldiv_warn(png_ptr, microns, 500, 127); -} - -png_fixed_point PNGAPI -png_get_x_offset_inches_fixed(png_const_structrp png_ptr, - png_const_inforp info_ptr) -{ - return png_fixed_inches_from_microns(png_ptr, - png_get_x_offset_microns(png_ptr, info_ptr)); -} -#endif - -#ifdef PNG_FIXED_POINT_SUPPORTED -png_fixed_point PNGAPI -png_get_y_offset_inches_fixed(png_const_structrp png_ptr, - png_const_inforp info_ptr) -{ - return png_fixed_inches_from_microns(png_ptr, - png_get_y_offset_microns(png_ptr, info_ptr)); -} -#endif - -#ifdef PNG_FLOATING_POINT_SUPPORTED -float PNGAPI -png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - /* To avoid the overflow do the conversion directly in floating - * point. - */ - return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937); -} -#endif - -#ifdef PNG_FLOATING_POINT_SUPPORTED -float PNGAPI -png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - /* To avoid the overflow do the conversion directly in floating - * point. - */ - return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937); -} -#endif - -#ifdef PNG_pHYs_SUPPORTED -png_uint_32 PNGAPI -png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr, - png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) -{ - png_uint_32 retval = 0; - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_pHYs) != 0) - { - png_debug1(1, "in %s retrieval function", "pHYs"); - - if (res_x != NULL) - { - *res_x = info_ptr->x_pixels_per_unit; - retval |= PNG_INFO_pHYs; - } - - if (res_y != NULL) - { - *res_y = info_ptr->y_pixels_per_unit; - retval |= PNG_INFO_pHYs; - } - - if (unit_type != NULL) - { - *unit_type = (int)info_ptr->phys_unit_type; - retval |= PNG_INFO_pHYs; - - if (*unit_type == 1) - { - if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50); - if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50); - } - } - } - - return (retval); -} -#endif /* pHYs */ -#endif /* INCH_CONVERSIONS */ - -/* png_get_channels really belongs in here, too, but it's been around longer */ - -#endif /* EASY_ACCESS */ - - -png_byte PNGAPI -png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return(info_ptr->channels); - - return (0); -} - -#ifdef PNG_READ_SUPPORTED -png_const_bytep PNGAPI -png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return(info_ptr->signature); - - return (NULL); -} -#endif - -#ifdef PNG_bKGD_SUPPORTED -png_uint_32 PNGAPI -png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr, - png_color_16p *background) -{ - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_bKGD) != 0 && - background != NULL) - { - png_debug1(1, "in %s retrieval function", "bKGD"); - - *background = &(info_ptr->background); - return (PNG_INFO_bKGD); - } - - return (0); -} -#endif - -#ifdef PNG_cHRM_SUPPORTED -/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the - * same time to correct the rgb grayscale coefficient defaults obtained from the - * cHRM chunk in 1.5.4 - */ -# ifdef PNG_FLOATING_POINT_SUPPORTED -png_uint_32 PNGAPI -png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr, - double *white_x, double *white_y, double *red_x, double *red_y, - double *green_x, double *green_y, double *blue_x, double *blue_y) -{ - /* Quiet API change: this code used to only return the end points if a cHRM - * chunk was present, but the end points can also come from iCCP or sRGB - * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and - * the png_set_ APIs merely check that set end points are mutually - * consistent. - */ - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) - { - png_debug1(1, "in %s retrieval function", "cHRM"); - - if (white_x != NULL) - *white_x = png_float(png_ptr, - info_ptr->colorspace.end_points_xy.whitex, "cHRM white X"); - if (white_y != NULL) - *white_y = png_float(png_ptr, - info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y"); - if (red_x != NULL) - *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx, - "cHRM red X"); - if (red_y != NULL) - *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy, - "cHRM red Y"); - if (green_x != NULL) - *green_x = png_float(png_ptr, - info_ptr->colorspace.end_points_xy.greenx, "cHRM green X"); - if (green_y != NULL) - *green_y = png_float(png_ptr, - info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y"); - if (blue_x != NULL) - *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex, - "cHRM blue X"); - if (blue_y != NULL) - *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey, - "cHRM blue Y"); - return (PNG_INFO_cHRM); - } - - return (0); -} - -png_uint_32 PNGAPI -png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr, - double *red_X, double *red_Y, double *red_Z, double *green_X, - double *green_Y, double *green_Z, double *blue_X, double *blue_Y, - double *blue_Z) -{ - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) - { - png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)"); - - if (red_X != NULL) - *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X, - "cHRM red X"); - if (red_Y != NULL) - *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y, - "cHRM red Y"); - if (red_Z != NULL) - *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z, - "cHRM red Z"); - if (green_X != NULL) - *green_X = png_float(png_ptr, - info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X"); - if (green_Y != NULL) - *green_Y = png_float(png_ptr, - info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y"); - if (green_Z != NULL) - *green_Z = png_float(png_ptr, - info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z"); - if (blue_X != NULL) - *blue_X = png_float(png_ptr, - info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X"); - if (blue_Y != NULL) - *blue_Y = png_float(png_ptr, - info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y"); - if (blue_Z != NULL) - *blue_Z = png_float(png_ptr, - info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z"); - return (PNG_INFO_cHRM); - } - - return (0); -} -# endif - -# ifdef PNG_FIXED_POINT_SUPPORTED -png_uint_32 PNGAPI -png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, - png_fixed_point *int_red_X, png_fixed_point *int_red_Y, - png_fixed_point *int_red_Z, png_fixed_point *int_green_X, - png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, - png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, - png_fixed_point *int_blue_Z) -{ - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) - { - png_debug1(1, "in %s retrieval function", "cHRM_XYZ"); - - if (int_red_X != NULL) - *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X; - if (int_red_Y != NULL) - *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y; - if (int_red_Z != NULL) - *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z; - if (int_green_X != NULL) - *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X; - if (int_green_Y != NULL) - *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y; - if (int_green_Z != NULL) - *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z; - if (int_blue_X != NULL) - *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X; - if (int_blue_Y != NULL) - *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y; - if (int_blue_Z != NULL) - *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z; - return (PNG_INFO_cHRM); - } - - return (0); -} - -png_uint_32 PNGAPI -png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, - png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x, - png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y, - png_fixed_point *blue_x, png_fixed_point *blue_y) -{ - png_debug1(1, "in %s retrieval function", "cHRM"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) - { - if (white_x != NULL) - *white_x = info_ptr->colorspace.end_points_xy.whitex; - if (white_y != NULL) - *white_y = info_ptr->colorspace.end_points_xy.whitey; - if (red_x != NULL) - *red_x = info_ptr->colorspace.end_points_xy.redx; - if (red_y != NULL) - *red_y = info_ptr->colorspace.end_points_xy.redy; - if (green_x != NULL) - *green_x = info_ptr->colorspace.end_points_xy.greenx; - if (green_y != NULL) - *green_y = info_ptr->colorspace.end_points_xy.greeny; - if (blue_x != NULL) - *blue_x = info_ptr->colorspace.end_points_xy.bluex; - if (blue_y != NULL) - *blue_y = info_ptr->colorspace.end_points_xy.bluey; - return (PNG_INFO_cHRM); - } - - return (0); -} -# endif -#endif - -#ifdef PNG_gAMA_SUPPORTED -# ifdef PNG_FIXED_POINT_SUPPORTED -png_uint_32 PNGAPI -png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, - png_fixed_point *file_gamma) -{ - png_debug1(1, "in %s retrieval function", "gAMA"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && - file_gamma != NULL) - { - *file_gamma = info_ptr->colorspace.gamma; - return (PNG_INFO_gAMA); - } - - return (0); -} -# endif - -# ifdef PNG_FLOATING_POINT_SUPPORTED -png_uint_32 PNGAPI -png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr, - double *file_gamma) -{ - png_debug1(1, "in %s retrieval function", "gAMA(float)"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && - file_gamma != NULL) - { - *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma, - "png_get_gAMA"); - return (PNG_INFO_gAMA); - } - - return (0); -} -# endif -#endif - -#ifdef PNG_sRGB_SUPPORTED -png_uint_32 PNGAPI -png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr, - int *file_srgb_intent) -{ - png_debug1(1, "in %s retrieval function", "sRGB"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_sRGB) != 0 && file_srgb_intent != NULL) - { - *file_srgb_intent = info_ptr->colorspace.rendering_intent; - return (PNG_INFO_sRGB); - } - - return (0); -} -#endif - -#ifdef PNG_iCCP_SUPPORTED -png_uint_32 PNGAPI -png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, - png_charpp name, int *compression_type, - png_bytepp profile, png_uint_32 *proflen) -{ - png_debug1(1, "in %s retrieval function", "iCCP"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_iCCP) != 0 && - name != NULL && compression_type != NULL && profile != NULL && - proflen != NULL) - { - *name = info_ptr->iccp_name; - *profile = info_ptr->iccp_profile; - *proflen = png_get_uint_32(info_ptr->iccp_profile); - /* This is somewhat irrelevant since the profile data returned has - * actually been uncompressed. - */ - *compression_type = PNG_COMPRESSION_TYPE_BASE; - return (PNG_INFO_iCCP); - } - - return (0); -} -#endif - -#ifdef PNG_sPLT_SUPPORTED -int PNGAPI -png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr, - png_sPLT_tpp spalettes) -{ - if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL) - { - *spalettes = info_ptr->splt_palettes; - return info_ptr->splt_palettes_num; - } - - return (0); -} -#endif - -#ifdef PNG_hIST_SUPPORTED -png_uint_32 PNGAPI -png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr, - png_uint_16p *hist) -{ - png_debug1(1, "in %s retrieval function", "hIST"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL) - { - *hist = info_ptr->hist; - return (PNG_INFO_hIST); - } - - return (0); -} -#endif - -png_uint_32 PNGAPI -png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr, - png_uint_32 *width, png_uint_32 *height, int *bit_depth, - int *color_type, int *interlace_type, int *compression_type, - int *filter_type) -{ - png_debug1(1, "in %s retrieval function", "IHDR"); - - if (png_ptr == NULL || info_ptr == NULL) - return (0); - - if (width != NULL) - *width = info_ptr->width; - - if (height != NULL) - *height = info_ptr->height; - - if (bit_depth != NULL) - *bit_depth = info_ptr->bit_depth; - - if (color_type != NULL) - *color_type = info_ptr->color_type; - - if (compression_type != NULL) - *compression_type = info_ptr->compression_type; - - if (filter_type != NULL) - *filter_type = info_ptr->filter_type; - - if (interlace_type != NULL) - *interlace_type = info_ptr->interlace_type; - - /* This is redundant if we can be sure that the info_ptr values were all - * assigned in png_set_IHDR(). We do the check anyhow in case an - * application has ignored our advice not to mess with the members - * of info_ptr directly. - */ - png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height, - info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type, - info_ptr->compression_type, info_ptr->filter_type); - - return (1); -} - -#ifdef PNG_oFFs_SUPPORTED -png_uint_32 PNGAPI -png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr, - png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type) -{ - png_debug1(1, "in %s retrieval function", "oFFs"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_oFFs) != 0 && - offset_x != NULL && offset_y != NULL && unit_type != NULL) - { - *offset_x = info_ptr->x_offset; - *offset_y = info_ptr->y_offset; - *unit_type = (int)info_ptr->offset_unit_type; - return (PNG_INFO_oFFs); - } - - return (0); -} -#endif - -#ifdef PNG_pCAL_SUPPORTED -png_uint_32 PNGAPI -png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr, - png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams, - png_charp *units, png_charpp *params) -{ - png_debug1(1, "in %s retrieval function", "pCAL"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_pCAL) != 0 && - purpose != NULL && X0 != NULL && X1 != NULL && type != NULL && - nparams != NULL && units != NULL && params != NULL) - { - *purpose = info_ptr->pcal_purpose; - *X0 = info_ptr->pcal_X0; - *X1 = info_ptr->pcal_X1; - *type = (int)info_ptr->pcal_type; - *nparams = (int)info_ptr->pcal_nparams; - *units = info_ptr->pcal_units; - *params = info_ptr->pcal_params; - return (PNG_INFO_pCAL); - } - - return (0); -} -#endif - -#ifdef PNG_sCAL_SUPPORTED -# ifdef PNG_FIXED_POINT_SUPPORTED -# if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ - defined(PNG_FLOATING_POINT_SUPPORTED) -png_uint_32 PNGAPI -png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, - int *unit, png_fixed_point *width, png_fixed_point *height) -{ - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_sCAL) != 0) - { - *unit = info_ptr->scal_unit; - /*TODO: make this work without FP support; the API is currently eliminated - * if neither floating point APIs nor internal floating point arithmetic - * are enabled. - */ - *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width"); - *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height), - "sCAL height"); - return (PNG_INFO_sCAL); - } - - return(0); -} -# endif /* FLOATING_ARITHMETIC */ -# endif /* FIXED_POINT */ -# ifdef PNG_FLOATING_POINT_SUPPORTED -png_uint_32 PNGAPI -png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr, - int *unit, double *width, double *height) -{ - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_sCAL) != 0) - { - *unit = info_ptr->scal_unit; - *width = atof(info_ptr->scal_s_width); - *height = atof(info_ptr->scal_s_height); - return (PNG_INFO_sCAL); - } - - return(0); -} -# endif /* FLOATING POINT */ -png_uint_32 PNGAPI -png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr, - int *unit, png_charpp width, png_charpp height) -{ - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_sCAL) != 0) - { - *unit = info_ptr->scal_unit; - *width = info_ptr->scal_s_width; - *height = info_ptr->scal_s_height; - return (PNG_INFO_sCAL); - } - - return(0); -} -#endif /* sCAL */ - -#ifdef PNG_pHYs_SUPPORTED -png_uint_32 PNGAPI -png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr, - png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) -{ - png_uint_32 retval = 0; - - png_debug1(1, "in %s retrieval function", "pHYs"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_pHYs) != 0) - { - if (res_x != NULL) - { - *res_x = info_ptr->x_pixels_per_unit; - retval |= PNG_INFO_pHYs; - } - - if (res_y != NULL) - { - *res_y = info_ptr->y_pixels_per_unit; - retval |= PNG_INFO_pHYs; - } - - if (unit_type != NULL) - { - *unit_type = (int)info_ptr->phys_unit_type; - retval |= PNG_INFO_pHYs; - } - } - - return (retval); -} -#endif /* pHYs */ - -png_uint_32 PNGAPI -png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr, - png_colorp *palette, int *num_palette) -{ - png_debug1(1, "in %s retrieval function", "PLTE"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_PLTE) != 0 && palette != NULL) - { - *palette = info_ptr->palette; - *num_palette = info_ptr->num_palette; - png_debug1(3, "num_palette = %d", *num_palette); - return (PNG_INFO_PLTE); - } - - return (0); -} - -#ifdef PNG_sBIT_SUPPORTED -png_uint_32 PNGAPI -png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr, - png_color_8p *sig_bit) -{ - png_debug1(1, "in %s retrieval function", "sBIT"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_sBIT) != 0 && sig_bit != NULL) - { - *sig_bit = &(info_ptr->sig_bit); - return (PNG_INFO_sBIT); - } - - return (0); -} -#endif - -#ifdef PNG_TEXT_SUPPORTED -int PNGAPI -png_get_text(png_const_structrp png_ptr, png_inforp info_ptr, - png_textp *text_ptr, int *num_text) -{ - if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0) - { - png_debug1(1, "in 0x%lx retrieval function", - (unsigned long)png_ptr->chunk_name); - - if (text_ptr != NULL) - *text_ptr = info_ptr->text; - - if (num_text != NULL) - *num_text = info_ptr->num_text; - - return info_ptr->num_text; - } - - if (num_text != NULL) - *num_text = 0; - - return(0); -} -#endif - -#ifdef PNG_tIME_SUPPORTED -png_uint_32 PNGAPI -png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr, - png_timep *mod_time) -{ - png_debug1(1, "in %s retrieval function", "tIME"); - - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL) - { - *mod_time = &(info_ptr->mod_time); - return (PNG_INFO_tIME); - } - - return (0); -} -#endif - -#ifdef PNG_tRNS_SUPPORTED -png_uint_32 PNGAPI -png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr, - png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color) -{ - png_uint_32 retval = 0; - if (png_ptr != NULL && info_ptr != NULL && - (info_ptr->valid & PNG_INFO_tRNS) != 0) - { - png_debug1(1, "in %s retrieval function", "tRNS"); - - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - if (trans_alpha != NULL) - { - *trans_alpha = info_ptr->trans_alpha; - retval |= PNG_INFO_tRNS; - } - - if (trans_color != NULL) - *trans_color = &(info_ptr->trans_color); - } - - else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */ - { - if (trans_color != NULL) - { - *trans_color = &(info_ptr->trans_color); - retval |= PNG_INFO_tRNS; - } - - if (trans_alpha != NULL) - *trans_alpha = NULL; - } - - if (num_trans != NULL) - { - *num_trans = info_ptr->num_trans; - retval |= PNG_INFO_tRNS; - } - } - - return (retval); -} -#endif - -#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED -int PNGAPI -png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr, - png_unknown_chunkpp unknowns) -{ - if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL) - { - *unknowns = info_ptr->unknown_chunks; - return info_ptr->unknown_chunks_num; - } - - return (0); -} -#endif - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -png_byte PNGAPI -png_get_rgb_to_gray_status (png_const_structrp png_ptr) -{ - return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0); -} -#endif - -#ifdef PNG_USER_CHUNKS_SUPPORTED -png_voidp PNGAPI -png_get_user_chunk_ptr(png_const_structrp png_ptr) -{ - return (png_ptr ? png_ptr->user_chunk_ptr : NULL); -} -#endif - -png_size_t PNGAPI -png_get_compression_buffer_size(png_const_structrp png_ptr) -{ - if (png_ptr == NULL) - return 0; - -#ifdef PNG_WRITE_SUPPORTED - if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) -#endif - { -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED - return png_ptr->IDAT_read_size; -#else - return PNG_IDAT_READ_SIZE; -#endif - } - -#ifdef PNG_WRITE_SUPPORTED - else - return png_ptr->zbuffer_size; -#endif -} - -#ifdef PNG_SET_USER_LIMITS_SUPPORTED -/* These functions were added to libpng 1.2.6 and were enabled - * by default in libpng-1.4.0 */ -png_uint_32 PNGAPI -png_get_user_width_max (png_const_structrp png_ptr) -{ - return (png_ptr ? png_ptr->user_width_max : 0); -} - -png_uint_32 PNGAPI -png_get_user_height_max (png_const_structrp png_ptr) -{ - return (png_ptr ? png_ptr->user_height_max : 0); -} - -/* This function was added to libpng 1.4.0 */ -png_uint_32 PNGAPI -png_get_chunk_cache_max (png_const_structrp png_ptr) -{ - return (png_ptr ? png_ptr->user_chunk_cache_max : 0); -} - -/* This function was added to libpng 1.4.1 */ -png_alloc_size_t PNGAPI -png_get_chunk_malloc_max (png_const_structrp png_ptr) -{ - return (png_ptr ? png_ptr->user_chunk_malloc_max : 0); -} -#endif /* SET_USER_LIMITS */ - -/* These functions were added to libpng 1.4.0 */ -#ifdef PNG_IO_STATE_SUPPORTED -png_uint_32 PNGAPI -png_get_io_state (png_const_structrp png_ptr) -{ - return png_ptr->io_state; -} - -png_uint_32 PNGAPI -png_get_io_chunk_type (png_const_structrp png_ptr) -{ - return png_ptr->chunk_name; -} -#endif /* IO_STATE */ - -#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED -# ifdef PNG_GET_PALETTE_MAX_SUPPORTED -int PNGAPI -png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr) -{ - if (png_ptr != NULL && info_ptr != NULL) - return png_ptr->num_palette_max; - - return (-1); -} -# endif -#endif - -#endif /* READ || WRITE */ diff --git a/third_party/libpng/pnginfo.h b/third_party/libpng/pnginfo.h deleted file mode 100644 index 361ed8be70..0000000000 --- a/third_party/libpng/pnginfo.h +++ /dev/null @@ -1,259 +0,0 @@ - -/* pnginfo.h - header file for PNG reference library - * - * Last changed in libpng 1.6.1 [March 28, 2013] - * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - - /* png_info is a structure that holds the information in a PNG file so - * that the application can find out the characteristics of the image. - * If you are reading the file, this structure will tell you what is - * in the PNG file. If you are writing the file, fill in the information - * you want to put into the PNG file, using png_set_*() functions, then - * call png_write_info(). - * - * The names chosen should be very close to the PNG specification, so - * consult that document for information about the meaning of each field. - * - * With libpng < 0.95, it was only possible to directly set and read the - * the values in the png_info_struct, which meant that the contents and - * order of the values had to remain fixed. With libpng 0.95 and later, - * however, there are now functions that abstract the contents of - * png_info_struct from the application, so this makes it easier to use - * libpng with dynamic libraries, and even makes it possible to use - * libraries that don't have all of the libpng ancillary chunk-handing - * functionality. In libpng-1.5.0 this was moved into a separate private - * file that is not visible to applications. - * - * The following members may have allocated storage attached that should be - * cleaned up before the structure is discarded: palette, trans, text, - * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile, - * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these - * are automatically freed when the info structure is deallocated, if they were - * allocated internally by libpng. This behavior can be changed by means - * of the png_data_freer() function. - * - * More allocation details: all the chunk-reading functions that - * change these members go through the corresponding png_set_* - * functions. A function to clear these members is available: see - * png_free_data(). The png_set_* functions do not depend on being - * able to point info structure members to any of the storage they are - * passed (they make their own copies), EXCEPT that the png_set_text - * functions use the same storage passed to them in the text_ptr or - * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns - * functions do not make their own copies. - */ -#ifndef PNGINFO_H -#define PNGINFO_H - -struct png_info_def -{ - /* The following are necessary for every PNG file */ - png_uint_32 width; /* width of image in pixels (from IHDR) */ - png_uint_32 height; /* height of image in pixels (from IHDR) */ - png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */ - png_size_t rowbytes; /* bytes needed to hold an untransformed row */ - png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */ - png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */ - png_uint_16 num_trans; /* number of transparent palette color (tRNS) */ - png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */ - png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */ - /* The following three should have been named *_method not *_type */ - png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */ - png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */ - png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ - - /* The following are set by png_set_IHDR, called from the application on - * write, but the are never actually used by the write code. - */ - png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */ - png_byte pixel_depth; /* number of bits per pixel */ - png_byte spare_byte; /* to align the data, and for future use */ - -#ifdef PNG_READ_SUPPORTED - /* This is never set during write */ - png_byte signature[8]; /* magic bytes read by libpng from start of file */ -#endif - - /* The rest of the data is optional. If you are reading, check the - * valid field to see if the information in these are valid. If you - * are writing, set the valid field to those chunks you want written, - * and initialize the appropriate fields below. - */ - -#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) - /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are - * defined. When COLORSPACE is switched on all the colorspace-defining - * chunks should be enabled, when GAMMA is switched on all the gamma-defining - * chunks should be enabled. If this is not done it becomes possible to read - * inconsistent PNG files and assign a probably incorrect interpretation to - * the information. (In other words, by carefully choosing which chunks to - * recognize the system configuration can select an interpretation for PNG - * files containing ambiguous data and this will result in inconsistent - * behavior between different libpng builds!) - */ - png_colorspace colorspace; -#endif - -#ifdef PNG_iCCP_SUPPORTED - /* iCCP chunk data. */ - png_charp iccp_name; /* profile name */ - png_bytep iccp_profile; /* International Color Consortium profile data */ - png_uint_32 iccp_proflen; /* ICC profile data length */ -#endif - -#ifdef PNG_TEXT_SUPPORTED - /* The tEXt, and zTXt chunks contain human-readable textual data in - * uncompressed, compressed, and optionally compressed forms, respectively. - * The data in "text" is an array of pointers to uncompressed, - * null-terminated C strings. Each chunk has a keyword that describes the - * textual data contained in that chunk. Keywords are not required to be - * unique, and the text string may be empty. Any number of text chunks may - * be in an image. - */ - int num_text; /* number of comments read or comments to write */ - int max_text; /* current size of text array */ - png_textp text; /* array of comments read or comments to write */ -#endif /* TEXT */ - -#ifdef PNG_tIME_SUPPORTED - /* The tIME chunk holds the last time the displayed image data was - * modified. See the png_time struct for the contents of this struct. - */ - png_time mod_time; -#endif - -#ifdef PNG_sBIT_SUPPORTED - /* The sBIT chunk specifies the number of significant high-order bits - * in the pixel data. Values are in the range [1, bit_depth], and are - * only specified for the channels in the pixel data. The contents of - * the low-order bits is not specified. Data is valid if - * (valid & PNG_INFO_sBIT) is non-zero. - */ - png_color_8 sig_bit; /* significant bits in color channels */ -#endif - -#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \ -defined(PNG_READ_BACKGROUND_SUPPORTED) - /* The tRNS chunk supplies transparency data for paletted images and - * other image types that don't need a full alpha channel. There are - * "num_trans" transparency values for a paletted image, stored in the - * same order as the palette colors, starting from index 0. Values - * for the data are in the range [0, 255], ranging from fully transparent - * to fully opaque, respectively. For non-paletted images, there is a - * single color specified that should be treated as fully transparent. - * Data is valid if (valid & PNG_INFO_tRNS) is non-zero. - */ - png_bytep trans_alpha; /* alpha values for paletted image */ - png_color_16 trans_color; /* transparent color for non-palette image */ -#endif - -#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - /* The bKGD chunk gives the suggested image background color if the - * display program does not have its own background color and the image - * is needs to composited onto a background before display. The colors - * in "background" are normally in the same color space/depth as the - * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero. - */ - png_color_16 background; -#endif - -#ifdef PNG_oFFs_SUPPORTED - /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards - * and downwards from the top-left corner of the display, page, or other - * application-specific co-ordinate space. See the PNG_OFFSET_ defines - * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero. - */ - png_int_32 x_offset; /* x offset on page */ - png_int_32 y_offset; /* y offset on page */ - png_byte offset_unit_type; /* offset units type */ -#endif - -#ifdef PNG_pHYs_SUPPORTED - /* The pHYs chunk gives the physical pixel density of the image for - * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_ - * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero. - */ - png_uint_32 x_pixels_per_unit; /* horizontal pixel density */ - png_uint_32 y_pixels_per_unit; /* vertical pixel density */ - png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */ -#endif - -#ifdef PNG_hIST_SUPPORTED - /* The hIST chunk contains the relative frequency or importance of the - * various palette entries, so that a viewer can intelligently select a - * reduced-color palette, if required. Data is an array of "num_palette" - * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST) - * is non-zero. - */ - png_uint_16p hist; -#endif - -#ifdef PNG_pCAL_SUPPORTED - /* The pCAL chunk describes a transformation between the stored pixel - * values and original physical data values used to create the image. - * The integer range [0, 2^bit_depth - 1] maps to the floating-point - * range given by [pcal_X0, pcal_X1], and are further transformed by a - * (possibly non-linear) transformation function given by "pcal_type" - * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_ - * defines below, and the PNG-Group's PNG extensions document for a - * complete description of the transformations and how they should be - * implemented, and for a description of the ASCII parameter strings. - * Data values are valid if (valid & PNG_INFO_pCAL) non-zero. - */ - png_charp pcal_purpose; /* pCAL chunk description string */ - png_int_32 pcal_X0; /* minimum value */ - png_int_32 pcal_X1; /* maximum value */ - png_charp pcal_units; /* Latin-1 string giving physical units */ - png_charpp pcal_params; /* ASCII strings containing parameter values */ - png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */ - png_byte pcal_nparams; /* number of parameters given in pcal_params */ -#endif - -/* New members added in libpng-1.0.6 */ - png_uint_32 free_me; /* flags items libpng is responsible for freeing */ - -#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED - /* Storage for unknown chunks that the library doesn't recognize. */ - png_unknown_chunkp unknown_chunks; - - /* The type of this field is limited by the type of - * png_struct::user_chunk_cache_max, else overflow can occur. - */ - int unknown_chunks_num; -#endif - -#ifdef PNG_sPLT_SUPPORTED - /* Data on sPLT chunks (there may be more than one). */ - png_sPLT_tp splt_palettes; - int splt_palettes_num; /* Match type returned by png_get API */ -#endif - -#ifdef PNG_sCAL_SUPPORTED - /* The sCAL chunk describes the actual physical dimensions of the - * subject matter of the graphic. The chunk contains a unit specification - * a byte value, and two ASCII strings representing floating-point - * values. The values are width and height corresponsing to one pixel - * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is - * non-zero. - */ - png_byte scal_unit; /* unit of physical scale */ - png_charp scal_s_width; /* string containing height */ - png_charp scal_s_height; /* string containing width */ -#endif - -#ifdef PNG_INFO_IMAGE_SUPPORTED - /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) - non-zero */ - /* Data valid if (valid & PNG_INFO_IDAT) non-zero */ - png_bytepp row_pointers; /* the image bits */ -#endif - -}; -#endif /* PNGINFO_H */ diff --git a/third_party/libpng/pnglibconf.h b/third_party/libpng/pnglibconf.h index db5c9ac21f..9e45f73129 100644 --- a/third_party/libpng/pnglibconf.h +++ b/third_party/libpng/pnglibconf.h @@ -1,10 +1,10 @@ -/* libpng 1.6.22rc01 STANDARD API DEFINITION */ +/* libpng 1.6.32 STANDARD API DEFINITION */ /* pnglibconf.h - library build configuration */ -/* Libpng version 1.6.22rc01 - May 14, 2016 */ +/* Libpng version 1.6.32 - August 24, 2017 */ -/* Copyright (c) 1998-2015 Glenn Randers-Pehrson */ +/* Copyright (c) 1998-2017 Glenn Randers-Pehrson */ /* This code is released under the libpng license. */ /* For conditions of distribution and use, see the disclaimer */ @@ -20,6 +20,8 @@ #define PNG_ALIGNED_MEMORY_SUPPORTED /*#undef PNG_ARM_NEON_API_SUPPORTED*/ /*#undef PNG_ARM_NEON_CHECK_SUPPORTED*/ +/*#undef PNG_POWERPC_VSX_API_SUPPORTED*/ +/*#undef PNG_POWERPC_VSX_CHECK_SUPPORTED*/ #define PNG_BENIGN_ERRORS_SUPPORTED #define PNG_BENIGN_READ_ERRORS_SUPPORTED /*#undef PNG_BENIGN_WRITE_ERRORS_SUPPORTED*/ @@ -82,6 +84,7 @@ #define PNG_READ_USER_TRANSFORM_SUPPORTED #define PNG_READ_bKGD_SUPPORTED #define PNG_READ_cHRM_SUPPORTED +#define PNG_READ_eXIf_SUPPORTED #define PNG_READ_gAMA_SUPPORTED #define PNG_READ_hIST_SUPPORTED #define PNG_READ_iCCP_SUPPORTED @@ -151,6 +154,7 @@ #define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED #define PNG_WRITE_bKGD_SUPPORTED #define PNG_WRITE_cHRM_SUPPORTED +#define PNG_WRITE_eXIf_SUPPORTED #define PNG_WRITE_gAMA_SUPPORTED #define PNG_WRITE_hIST_SUPPORTED #define PNG_WRITE_iCCP_SUPPORTED @@ -168,6 +172,7 @@ #define PNG_WRITE_zTXt_SUPPORTED #define PNG_bKGD_SUPPORTED #define PNG_cHRM_SUPPORTED +#define PNG_eXIf_SUPPORTED #define PNG_gAMA_SUPPORTED #define PNG_hIST_SUPPORTED #define PNG_iCCP_SUPPORTED @@ -212,10 +217,4 @@ #define PNG_sCAL_PRECISION 5 #define PNG_sRGB_PROFILE_CHECKS 2 /* end of settings */ - -/* Skia-specific settings */ -#define PNG_PREFIX -#include "pngprefix.h" -/* end of Skia-specific settings */ - #endif /* PNGLCONF_H */ diff --git a/third_party/libpng/pngmem.c b/third_party/libpng/pngmem.c deleted file mode 100644 index 7bcfd00507..0000000000 --- a/third_party/libpng/pngmem.c +++ /dev/null @@ -1,284 +0,0 @@ - -/* pngmem.c - stub functions for memory allocation - * - * Last changed in libpng 1.6.15 [November 20, 2014] - * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This file provides a location for all memory allocation. Users who - * need special memory handling are expected to supply replacement - * functions for png_malloc() and png_free(), and to use - * png_create_read_struct_2() and png_create_write_struct_2() to - * identify the replacement functions. - */ - -#include "pngpriv.h" - -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) -/* Free a png_struct */ -void /* PRIVATE */ -png_destroy_png_struct(png_structrp png_ptr) -{ - if (png_ptr != NULL) - { - /* png_free might call png_error and may certainly call - * png_get_mem_ptr, so fake a temporary png_struct to support this. - */ - png_struct dummy_struct = *png_ptr; - memset(png_ptr, 0, (sizeof *png_ptr)); - png_free(&dummy_struct, png_ptr); - -# ifdef PNG_SETJMP_SUPPORTED - /* We may have a jmp_buf left to deallocate. */ - png_free_jmpbuf(&dummy_struct); -# endif - } -} - -/* Allocate memory. For reasonable files, size should never exceed - * 64K. However, zlib may allocate more than 64K if you don't tell - * it not to. See zconf.h and png.h for more information. zlib does - * need to allocate exactly 64K, so whatever you call here must - * have the ability to do that. - */ -PNG_FUNCTION(png_voidp,PNGAPI -png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) -{ - png_voidp ret; - - ret = png_malloc(png_ptr, size); - - if (ret != NULL) - memset(ret, 0, size); - - return ret; -} - -/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of - * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED. - * Checking and error handling must happen outside this routine; it returns NULL - * if the allocation cannot be done (for any reason.) - */ -PNG_FUNCTION(png_voidp /* PRIVATE */, -png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size), - PNG_ALLOCATED) -{ - /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS - * allocators have also been removed in 1.6.0, so any 16-bit system now has - * to implement a user memory handler. This checks to be sure it isn't - * called with big numbers. - */ -#ifndef PNG_USER_MEM_SUPPORTED - PNG_UNUSED(png_ptr) -#endif - - /* Some compilers complain that this is always true. However, it - * can be false when integer overflow happens. - */ - if (size > 0 && size <= PNG_SIZE_MAX -# ifdef PNG_MAX_MALLOC_64K - && size <= 65536U -# endif - ) - { -#ifdef PNG_USER_MEM_SUPPORTED - if (png_ptr != NULL && png_ptr->malloc_fn != NULL) - return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size); - - else -#endif - return malloc((size_t)size); /* checked for truncation above */ - } - - else - return NULL; -} - -#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\ - defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) -/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7 - * that arises because of the checks in png_realloc_array that are repeated in - * png_malloc_array. - */ -static png_voidp -png_malloc_array_checked(png_const_structrp png_ptr, int nelements, - size_t element_size) -{ - png_alloc_size_t req = nelements; /* known to be > 0 */ - - if (req <= PNG_SIZE_MAX/element_size) - return png_malloc_base(png_ptr, req * element_size); - - /* The failure case when the request is too large */ - return NULL; -} - -PNG_FUNCTION(png_voidp /* PRIVATE */, -png_malloc_array,(png_const_structrp png_ptr, int nelements, - size_t element_size),PNG_ALLOCATED) -{ - if (nelements <= 0 || element_size == 0) - png_error(png_ptr, "internal error: array alloc"); - - return png_malloc_array_checked(png_ptr, nelements, element_size); -} - -PNG_FUNCTION(png_voidp /* PRIVATE */, -png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array, - int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED) -{ - /* These are internal errors: */ - if (add_elements <= 0 || element_size == 0 || old_elements < 0 || - (old_array == NULL && old_elements > 0)) - png_error(png_ptr, "internal error: array realloc"); - - /* Check for overflow on the elements count (so the caller does not have to - * check.) - */ - if (add_elements <= INT_MAX - old_elements) - { - png_voidp new_array = png_malloc_array_checked(png_ptr, - old_elements+add_elements, element_size); - - if (new_array != NULL) - { - /* Because png_malloc_array worked the size calculations below cannot - * overflow. - */ - if (old_elements > 0) - memcpy(new_array, old_array, element_size*(unsigned)old_elements); - - memset((char*)new_array + element_size*(unsigned)old_elements, 0, - element_size*(unsigned)add_elements); - - return new_array; - } - } - - return NULL; /* error */ -} -#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */ - -/* Various functions that have different error handling are derived from this. - * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate - * function png_malloc_default is also provided. - */ -PNG_FUNCTION(png_voidp,PNGAPI -png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) -{ - png_voidp ret; - - if (png_ptr == NULL) - return NULL; - - ret = png_malloc_base(png_ptr, size); - - if (ret == NULL) - png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */ - - return ret; -} - -#ifdef PNG_USER_MEM_SUPPORTED -PNG_FUNCTION(png_voidp,PNGAPI -png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size), - PNG_ALLOCATED PNG_DEPRECATED) -{ - png_voidp ret; - - if (png_ptr == NULL) - return NULL; - - /* Passing 'NULL' here bypasses the application provided memory handler. */ - ret = png_malloc_base(NULL/*use malloc*/, size); - - if (ret == NULL) - png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */ - - return ret; -} -#endif /* USER_MEM */ - -/* This function was added at libpng version 1.2.3. The png_malloc_warn() - * function will issue a png_warning and return NULL instead of issuing a - * png_error, if it fails to allocate the requested memory. - */ -PNG_FUNCTION(png_voidp,PNGAPI -png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size), - PNG_ALLOCATED) -{ - if (png_ptr != NULL) - { - png_voidp ret = png_malloc_base(png_ptr, size); - - if (ret != NULL) - return ret; - - png_warning(png_ptr, "Out of memory"); - } - - return NULL; -} - -/* Free a pointer allocated by png_malloc(). If ptr is NULL, return - * without taking any action. - */ -void PNGAPI -png_free(png_const_structrp png_ptr, png_voidp ptr) -{ - if (png_ptr == NULL || ptr == NULL) - return; - -#ifdef PNG_USER_MEM_SUPPORTED - if (png_ptr->free_fn != NULL) - png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr); - - else - png_free_default(png_ptr, ptr); -} - -PNG_FUNCTION(void,PNGAPI -png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED) -{ - if (png_ptr == NULL || ptr == NULL) - return; -#endif /* USER_MEM */ - - free(ptr); -} - -#ifdef PNG_USER_MEM_SUPPORTED -/* This function is called when the application wants to use another method - * of allocating and freeing memory. - */ -void PNGAPI -png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr - malloc_fn, png_free_ptr free_fn) -{ - if (png_ptr != NULL) - { - png_ptr->mem_ptr = mem_ptr; - png_ptr->malloc_fn = malloc_fn; - png_ptr->free_fn = free_fn; - } -} - -/* This function returns a pointer to the mem_ptr associated with the user - * functions. The application should free any memory associated with this - * pointer before png_write_destroy and png_read_destroy are called. - */ -png_voidp PNGAPI -png_get_mem_ptr(png_const_structrp png_ptr) -{ - if (png_ptr == NULL) - return NULL; - - return png_ptr->mem_ptr; -} -#endif /* USER_MEM */ -#endif /* READ || WRITE */ diff --git a/third_party/libpng/pngpread.c b/third_party/libpng/pngpread.c deleted file mode 100644 index 0266cbe43a..0000000000 --- a/third_party/libpng/pngpread.c +++ /dev/null @@ -1,1096 +0,0 @@ - -/* pngpread.c - read a png file in push mode - * - * Last changed in libpng 1.6.18 [July 23, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "pngpriv.h" - -#ifdef PNG_PROGRESSIVE_READ_SUPPORTED - -/* Push model modes */ -#define PNG_READ_SIG_MODE 0 -#define PNG_READ_CHUNK_MODE 1 -#define PNG_READ_IDAT_MODE 2 -#define PNG_READ_tEXt_MODE 4 -#define PNG_READ_zTXt_MODE 5 -#define PNG_READ_DONE_MODE 6 -#define PNG_READ_iTXt_MODE 7 -#define PNG_ERROR_MODE 8 - -#define PNG_PUSH_SAVE_BUFFER_IF_FULL \ -if (png_ptr->push_length + 4 > png_ptr->buffer_size) \ - { png_push_save_buffer(png_ptr); return; } -#define PNG_PUSH_SAVE_BUFFER_IF_LT(N) \ -if (png_ptr->buffer_size < N) \ - { png_push_save_buffer(png_ptr); return; } - -void PNGAPI -png_process_data(png_structrp png_ptr, png_inforp info_ptr, - png_bytep buffer, png_size_t buffer_size) -{ - if (png_ptr == NULL || info_ptr == NULL) - return; - - png_push_restore_buffer(png_ptr, buffer, buffer_size); - - while (png_ptr->buffer_size) - { - png_process_some_data(png_ptr, info_ptr); - } -} - -png_size_t PNGAPI -png_process_data_pause(png_structrp png_ptr, int save) -{ - if (png_ptr != NULL) - { - /* It's easiest for the caller if we do the save; then the caller doesn't - * have to supply the same data again: - */ - if (save != 0) - png_push_save_buffer(png_ptr); - else - { - /* This includes any pending saved bytes: */ - png_size_t remaining = png_ptr->buffer_size; - png_ptr->buffer_size = 0; - - /* So subtract the saved buffer size, unless all the data - * is actually 'saved', in which case we just return 0 - */ - if (png_ptr->save_buffer_size < remaining) - return remaining - png_ptr->save_buffer_size; - } - } - - return 0; -} - -png_uint_32 PNGAPI -png_process_data_skip(png_structrp png_ptr) -{ - /* TODO: Deprecate and remove this API. - * Somewhere the implementation of this seems to have been lost, - * or abandoned. It was only to support some internal back-door access - * to png_struct) in libpng-1.4.x. - */ - png_app_warning(png_ptr, -"png_process_data_skip is not implemented in any current version of libpng"); - return 0; -} - -/* What we do with the incoming data depends on what we were previously - * doing before we ran out of data... - */ -void /* PRIVATE */ -png_process_some_data(png_structrp png_ptr, png_inforp info_ptr) -{ - if (png_ptr == NULL) - return; - - switch (png_ptr->process_mode) - { - case PNG_READ_SIG_MODE: - { - png_push_read_sig(png_ptr, info_ptr); - break; - } - - case PNG_READ_CHUNK_MODE: - { - png_push_read_chunk(png_ptr, info_ptr); - break; - } - - case PNG_READ_IDAT_MODE: - { - png_push_read_IDAT(png_ptr); - break; - } - - default: - { - png_ptr->buffer_size = 0; - break; - } - } -} - -/* Read any remaining signature bytes from the stream and compare them with - * the correct PNG signature. It is possible that this routine is called - * with bytes already read from the signature, either because they have been - * checked by the calling application, or because of multiple calls to this - * routine. - */ -void /* PRIVATE */ -png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr) -{ - png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */ - num_to_check = 8 - num_checked; - - if (png_ptr->buffer_size < num_to_check) - { - num_to_check = png_ptr->buffer_size; - } - - png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), - num_to_check); - png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check); - - if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) - { - if (num_checked < 4 && - png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) - png_error(png_ptr, "Not a PNG file"); - - else - png_error(png_ptr, "PNG file corrupted by ASCII conversion"); - } - else - { - if (png_ptr->sig_bytes >= 8) - { - png_ptr->process_mode = PNG_READ_CHUNK_MODE; - } - } -} - -void /* PRIVATE */ -png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr) -{ - png_uint_32 chunk_name; -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - int keep; /* unknown handling method */ -#endif - - /* First we make sure we have enough data for the 4-byte chunk name - * and the 4-byte chunk length before proceeding with decoding the - * chunk data. To fully decode each of these chunks, we also make - * sure we have enough data in the buffer for the 4-byte CRC at the - * end of every chunk (except IDAT, which is handled separately). - */ - if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0) - { - png_byte chunk_length[4]; - png_byte chunk_tag[4]; - - PNG_PUSH_SAVE_BUFFER_IF_LT(8) - png_push_fill_buffer(png_ptr, chunk_length, 4); - png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); - png_reset_crc(png_ptr); - png_crc_read(png_ptr, chunk_tag, 4); - png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); - png_check_chunk_name(png_ptr, png_ptr->chunk_name); - png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; - } - - chunk_name = png_ptr->chunk_name; - - if (chunk_name == png_IDAT) - { - if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) - png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; - - /* If we reach an IDAT chunk, this means we have read all of the - * header chunks, and we can start reading the image (or if this - * is called after the image has been read - we have an error). - */ - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_error(png_ptr, "Missing IHDR before IDAT"); - - else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && - (png_ptr->mode & PNG_HAVE_PLTE) == 0) - png_error(png_ptr, "Missing PLTE before IDAT"); - - png_ptr->mode |= PNG_HAVE_IDAT; - png_ptr->process_mode = PNG_READ_IDAT_MODE; - - if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0) - if (png_ptr->push_length == 0) - return; - - if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) - png_benign_error(png_ptr, "Too many IDATs found"); - } - - if (chunk_name == png_IHDR) - { - if (png_ptr->push_length != 13) - png_error(png_ptr, "Invalid IHDR length"); - - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); - } - - else if (chunk_name == png_IEND) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); - - png_ptr->process_mode = PNG_READ_DONE_MODE; - png_push_have_end(png_ptr, info_ptr); - } - -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep); - - if (chunk_name == png_PLTE) - png_ptr->mode |= PNG_HAVE_PLTE; - } -#endif - - else if (chunk_name == png_PLTE) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); - } - - else if (chunk_name == png_IDAT) - { - png_ptr->idat_size = png_ptr->push_length; - png_ptr->process_mode = PNG_READ_IDAT_MODE; - png_push_have_info(png_ptr, info_ptr); - png_ptr->zstream.avail_out = - (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, - png_ptr->iwidth) + 1; - png_ptr->zstream.next_out = png_ptr->row_buf; - return; - } - -#ifdef PNG_READ_gAMA_SUPPORTED - else if (png_ptr->chunk_name == png_gAMA) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_sBIT_SUPPORTED - else if (png_ptr->chunk_name == png_sBIT) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_cHRM_SUPPORTED - else if (png_ptr->chunk_name == png_cHRM) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_sRGB_SUPPORTED - else if (chunk_name == png_sRGB) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_iCCP_SUPPORTED - else if (png_ptr->chunk_name == png_iCCP) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_sPLT_SUPPORTED - else if (chunk_name == png_sPLT) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_tRNS_SUPPORTED - else if (chunk_name == png_tRNS) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_bKGD_SUPPORTED - else if (chunk_name == png_bKGD) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_hIST_SUPPORTED - else if (chunk_name == png_hIST) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_pHYs_SUPPORTED - else if (chunk_name == png_pHYs) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_oFFs_SUPPORTED - else if (chunk_name == png_oFFs) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); - } -#endif - -#ifdef PNG_READ_pCAL_SUPPORTED - else if (chunk_name == png_pCAL) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_sCAL_SUPPORTED - else if (chunk_name == png_sCAL) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_tIME_SUPPORTED - else if (chunk_name == png_tIME) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_tEXt_SUPPORTED - else if (chunk_name == png_tEXt) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_zTXt_SUPPORTED - else if (chunk_name == png_zTXt) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_iTXt_SUPPORTED - else if (chunk_name == png_iTXt) - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); - } -#endif - - else - { - PNG_PUSH_SAVE_BUFFER_IF_FULL - png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, - PNG_HANDLE_CHUNK_AS_DEFAULT); - } - - png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; -} - -void PNGCBAPI -png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) -{ - png_bytep ptr; - - if (png_ptr == NULL) - return; - - ptr = buffer; - if (png_ptr->save_buffer_size != 0) - { - png_size_t save_size; - - if (length < png_ptr->save_buffer_size) - save_size = length; - - else - save_size = png_ptr->save_buffer_size; - - memcpy(ptr, png_ptr->save_buffer_ptr, save_size); - length -= save_size; - ptr += save_size; - png_ptr->buffer_size -= save_size; - png_ptr->save_buffer_size -= save_size; - png_ptr->save_buffer_ptr += save_size; - } - if (length != 0 && png_ptr->current_buffer_size != 0) - { - png_size_t save_size; - - if (length < png_ptr->current_buffer_size) - save_size = length; - - else - save_size = png_ptr->current_buffer_size; - - memcpy(ptr, png_ptr->current_buffer_ptr, save_size); - png_ptr->buffer_size -= save_size; - png_ptr->current_buffer_size -= save_size; - png_ptr->current_buffer_ptr += save_size; - } -} - -void /* PRIVATE */ -png_push_save_buffer(png_structrp png_ptr) -{ - if (png_ptr->save_buffer_size != 0) - { - if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) - { - png_size_t i, istop; - png_bytep sp; - png_bytep dp; - - istop = png_ptr->save_buffer_size; - for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; - i < istop; i++, sp++, dp++) - { - *dp = *sp; - } - } - } - if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > - png_ptr->save_buffer_max) - { - png_size_t new_max; - png_bytep old_buffer; - - if (png_ptr->save_buffer_size > PNG_SIZE_MAX - - (png_ptr->current_buffer_size + 256)) - { - png_error(png_ptr, "Potential overflow of save_buffer"); - } - - new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; - old_buffer = png_ptr->save_buffer; - png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, - (png_size_t)new_max); - - if (png_ptr->save_buffer == NULL) - { - png_free(png_ptr, old_buffer); - png_error(png_ptr, "Insufficient memory for save_buffer"); - } - -#if 0 - // This is the code checked into libpng. Calling memcpy with a null - // source is undefined, even if count is 0, but libpng does not - // currently check for null or 0. The Skia fix is below. - // skbug.com/5390 - memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); -#else - if (old_buffer) - memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); - else if (png_ptr->save_buffer_size) - png_error(png_ptr, "save_buffer error"); -#endif - png_free(png_ptr, old_buffer); - png_ptr->save_buffer_max = new_max; - } - if (png_ptr->current_buffer_size) - { - memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, - png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); - png_ptr->save_buffer_size += png_ptr->current_buffer_size; - png_ptr->current_buffer_size = 0; - } - png_ptr->save_buffer_ptr = png_ptr->save_buffer; - png_ptr->buffer_size = 0; -} - -void /* PRIVATE */ -png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer, - png_size_t buffer_length) -{ - png_ptr->current_buffer = buffer; - png_ptr->current_buffer_size = buffer_length; - png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; - png_ptr->current_buffer_ptr = png_ptr->current_buffer; -} - -void /* PRIVATE */ -png_push_read_IDAT(png_structrp png_ptr) -{ - if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0) - { - png_byte chunk_length[4]; - png_byte chunk_tag[4]; - - /* TODO: this code can be commoned up with the same code in push_read */ - PNG_PUSH_SAVE_BUFFER_IF_LT(8) - png_push_fill_buffer(png_ptr, chunk_length, 4); - png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); - png_reset_crc(png_ptr); - png_crc_read(png_ptr, chunk_tag, 4); - png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); - png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; - - if (png_ptr->chunk_name != png_IDAT) - { - png_ptr->process_mode = PNG_READ_CHUNK_MODE; - - if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) - png_error(png_ptr, "Not enough compressed data"); - - return; - } - - png_ptr->idat_size = png_ptr->push_length; - } - - if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0) - { - png_size_t save_size = png_ptr->save_buffer_size; - png_uint_32 idat_size = png_ptr->idat_size; - - /* We want the smaller of 'idat_size' and 'current_buffer_size', but they - * are of different types and we don't know which variable has the fewest - * bits. Carefully select the smaller and cast it to the type of the - * larger - this cannot overflow. Do not cast in the following test - it - * will break on either 16-bit or 64-bit platforms. - */ - if (idat_size < save_size) - save_size = (png_size_t)idat_size; - - else - idat_size = (png_uint_32)save_size; - - png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); - - png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); - - png_ptr->idat_size -= idat_size; - png_ptr->buffer_size -= save_size; - png_ptr->save_buffer_size -= save_size; - png_ptr->save_buffer_ptr += save_size; - } - - if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0) - { - png_size_t save_size = png_ptr->current_buffer_size; - png_uint_32 idat_size = png_ptr->idat_size; - - /* We want the smaller of 'idat_size' and 'current_buffer_size', but they - * are of different types and we don't know which variable has the fewest - * bits. Carefully select the smaller and cast it to the type of the - * larger - this cannot overflow. - */ - if (idat_size < save_size) - save_size = (png_size_t)idat_size; - - else - idat_size = (png_uint_32)save_size; - - png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); - - png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); - - png_ptr->idat_size -= idat_size; - png_ptr->buffer_size -= save_size; - png_ptr->current_buffer_size -= save_size; - png_ptr->current_buffer_ptr += save_size; - } - - if (png_ptr->idat_size == 0) - { - PNG_PUSH_SAVE_BUFFER_IF_LT(4) - png_crc_finish(png_ptr, 0); - png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; - png_ptr->mode |= PNG_AFTER_IDAT; - png_ptr->zowner = 0; - } -} - -void /* PRIVATE */ -png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer, - png_size_t buffer_length) -{ - /* The caller checks for a non-zero buffer length. */ - if (!(buffer_length > 0) || buffer == NULL) - png_error(png_ptr, "No IDAT data (internal error)"); - - /* This routine must process all the data it has been given - * before returning, calling the row callback as required to - * handle the uncompressed results. - */ - png_ptr->zstream.next_in = buffer; - /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ - png_ptr->zstream.avail_in = (uInt)buffer_length; - - /* Keep going until the decompressed data is all processed - * or the stream marked as finished. - */ - while (png_ptr->zstream.avail_in > 0 && - (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) - { - int ret; - - /* We have data for zlib, but we must check that zlib - * has someplace to put the results. It doesn't matter - * if we don't expect any results -- it may be the input - * data is just the LZ end code. - */ - if (!(png_ptr->zstream.avail_out > 0)) - { - /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ - png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, - png_ptr->iwidth) + 1); - - png_ptr->zstream.next_out = png_ptr->row_buf; - } - - /* Using Z_SYNC_FLUSH here means that an unterminated - * LZ stream (a stream with a missing end code) can still - * be handled, otherwise (Z_NO_FLUSH) a future zlib - * implementation might defer output and therefore - * change the current behavior (see comments in inflate.c - * for why this doesn't happen at present with zlib 1.2.5). - */ - ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH); - - /* Check for any failure before proceeding. */ - if (ret != Z_OK && ret != Z_STREAM_END) - { - /* Terminate the decompression. */ - png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; - png_ptr->zowner = 0; - - /* This may be a truncated stream (missing or - * damaged end code). Treat that as a warning. - */ - if (png_ptr->row_number >= png_ptr->num_rows || - png_ptr->pass > 6) - png_warning(png_ptr, "Truncated compressed data in IDAT"); - - else - png_error(png_ptr, "Decompression error in IDAT"); - - /* Skip the check on unprocessed input */ - return; - } - - /* Did inflate output any data? */ - if (png_ptr->zstream.next_out != png_ptr->row_buf) - { - /* Is this unexpected data after the last row? - * If it is, artificially terminate the LZ output - * here. - */ - if (png_ptr->row_number >= png_ptr->num_rows || - png_ptr->pass > 6) - { - /* Extra data. */ - png_warning(png_ptr, "Extra compressed data in IDAT"); - png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; - png_ptr->zowner = 0; - - /* Do no more processing; skip the unprocessed - * input check below. - */ - return; - } - - /* Do we have a complete row? */ - if (png_ptr->zstream.avail_out == 0) - png_push_process_row(png_ptr); - } - - /* And check for the end of the stream. */ - if (ret == Z_STREAM_END) - png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; - } - - /* All the data should have been processed, if anything - * is left at this point we have bytes of IDAT data - * after the zlib end code. - */ - if (png_ptr->zstream.avail_in > 0) - png_warning(png_ptr, "Extra compression data in IDAT"); -} - -void /* PRIVATE */ -png_push_process_row(png_structrp png_ptr) -{ - /* 1.5.6: row_info moved out of png_struct to a local here. */ - png_row_info row_info; - - row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ - row_info.color_type = png_ptr->color_type; - row_info.bit_depth = png_ptr->bit_depth; - row_info.channels = png_ptr->channels; - row_info.pixel_depth = png_ptr->pixel_depth; - row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); - - if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) - { - if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) - png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, - png_ptr->prev_row + 1, png_ptr->row_buf[0]); - else - png_error(png_ptr, "bad adaptive filter value"); - } - - /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before - * 1.5.6, while the buffer really is this big in current versions of libpng - * it may not be in the future, so this was changed just to copy the - * interlaced row count: - */ - memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - if (png_ptr->transformations != 0) - png_do_read_transformations(png_ptr, &row_info); -#endif - - /* The transformed pixel depth should match the depth now in row_info. */ - if (png_ptr->transformed_pixel_depth == 0) - { - png_ptr->transformed_pixel_depth = row_info.pixel_depth; - if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) - png_error(png_ptr, "progressive row overflow"); - } - - else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) - png_error(png_ptr, "internal progressive row size calculation error"); - - -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Expand interlaced rows to full size */ - if (png_ptr->interlaced != 0 && - (png_ptr->transformations & PNG_INTERLACE) != 0) - { - if (png_ptr->pass < 6) - png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, - png_ptr->transformations); - - switch (png_ptr->pass) - { - case 0: - { - int i; - for (i = 0; i < 8 && png_ptr->pass == 0; i++) - { - png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */ - } - - if (png_ptr->pass == 2) /* Pass 1 might be empty */ - { - for (i = 0; i < 4 && png_ptr->pass == 2; i++) - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - } - - if (png_ptr->pass == 4 && png_ptr->height <= 4) - { - for (i = 0; i < 2 && png_ptr->pass == 4; i++) - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - } - - if (png_ptr->pass == 6 && png_ptr->height <= 4) - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - - break; - } - - case 1: - { - int i; - for (i = 0; i < 8 && png_ptr->pass == 1; i++) - { - png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); - } - - if (png_ptr->pass == 2) /* Skip top 4 generated rows */ - { - for (i = 0; i < 4 && png_ptr->pass == 2; i++) - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - } - - break; - } - - case 2: - { - int i; - - for (i = 0; i < 4 && png_ptr->pass == 2; i++) - { - png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); - } - - for (i = 0; i < 4 && png_ptr->pass == 2; i++) - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - - if (png_ptr->pass == 4) /* Pass 3 might be empty */ - { - for (i = 0; i < 2 && png_ptr->pass == 4; i++) - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - } - - break; - } - - case 3: - { - int i; - - for (i = 0; i < 4 && png_ptr->pass == 3; i++) - { - png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); - } - - if (png_ptr->pass == 4) /* Skip top two generated rows */ - { - for (i = 0; i < 2 && png_ptr->pass == 4; i++) - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - } - - break; - } - - case 4: - { - int i; - - for (i = 0; i < 2 && png_ptr->pass == 4; i++) - { - png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); - } - - for (i = 0; i < 2 && png_ptr->pass == 4; i++) - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - - if (png_ptr->pass == 6) /* Pass 5 might be empty */ - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - - break; - } - - case 5: - { - int i; - - for (i = 0; i < 2 && png_ptr->pass == 5; i++) - { - png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); - } - - if (png_ptr->pass == 6) /* Skip top generated row */ - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - - break; - } - - default: - case 6: - { - png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); - - if (png_ptr->pass != 6) - break; - - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - } - } - else -#endif - { - png_push_have_row(png_ptr, png_ptr->row_buf + 1); - png_read_push_finish_row(png_ptr); - } -} - -void /* PRIVATE */ -png_read_push_finish_row(png_structrp png_ptr) -{ -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; - - /* Height of interlace block. This is not currently used - if you need - * it, uncomment it here and in png.h - static PNG_CONST png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; - */ -#endif - - png_ptr->row_number++; - if (png_ptr->row_number < png_ptr->num_rows) - return; - -#ifdef PNG_READ_INTERLACING_SUPPORTED - if (png_ptr->interlaced != 0) - { - png_ptr->row_number = 0; - memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); - - do - { - png_ptr->pass++; - if ((png_ptr->pass == 1 && png_ptr->width < 5) || - (png_ptr->pass == 3 && png_ptr->width < 3) || - (png_ptr->pass == 5 && png_ptr->width < 2)) - png_ptr->pass++; - - if (png_ptr->pass > 7) - png_ptr->pass--; - - if (png_ptr->pass >= 7) - break; - - png_ptr->iwidth = (png_ptr->width + - png_pass_inc[png_ptr->pass] - 1 - - png_pass_start[png_ptr->pass]) / - png_pass_inc[png_ptr->pass]; - - if ((png_ptr->transformations & PNG_INTERLACE) != 0) - break; - - png_ptr->num_rows = (png_ptr->height + - png_pass_yinc[png_ptr->pass] - 1 - - png_pass_ystart[png_ptr->pass]) / - png_pass_yinc[png_ptr->pass]; - - } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); - } -#endif /* READ_INTERLACING */ -} - -void /* PRIVATE */ -png_push_have_info(png_structrp png_ptr, png_inforp info_ptr) -{ - if (png_ptr->info_fn != NULL) - (*(png_ptr->info_fn))(png_ptr, info_ptr); -} - -void /* PRIVATE */ -png_push_have_end(png_structrp png_ptr, png_inforp info_ptr) -{ - if (png_ptr->end_fn != NULL) - (*(png_ptr->end_fn))(png_ptr, info_ptr); -} - -void /* PRIVATE */ -png_push_have_row(png_structrp png_ptr, png_bytep row) -{ - if (png_ptr->row_fn != NULL) - (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, - (int)png_ptr->pass); -} - -#ifdef PNG_READ_INTERLACING_SUPPORTED -void PNGAPI -png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row, - png_const_bytep new_row) -{ - if (png_ptr == NULL) - return; - - /* new_row is a flag here - if it is NULL then the app callback was called - * from an empty row (see the calls to png_struct::row_fn below), otherwise - * it must be png_ptr->row_buf+1 - */ - if (new_row != NULL) - png_combine_row(png_ptr, old_row, 1/*blocky display*/); -} -#endif /* READ_INTERLACING */ - -void PNGAPI -png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr, - png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, - png_progressive_end_ptr end_fn) -{ - if (png_ptr == NULL) - return; - - png_ptr->info_fn = info_fn; - png_ptr->row_fn = row_fn; - png_ptr->end_fn = end_fn; - - png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); -} - -png_voidp PNGAPI -png_get_progressive_ptr(png_const_structrp png_ptr) -{ - if (png_ptr == NULL) - return (NULL); - - return png_ptr->io_ptr; -} -#endif /* PROGRESSIVE_READ */ diff --git a/third_party/libpng/pngprefix.h b/third_party/libpng/pngprefix.h deleted file mode 100644 index 0a9acb2037..0000000000 --- a/third_party/libpng/pngprefix.h +++ /dev/null @@ -1,455 +0,0 @@ -/* - * Copyright 2016 Google Inc. - * - * Use of this source code is governed by a BSD-style license that can be - * found in the LICENSE file. - */ - -#ifndef PNGPREFIX_H -#define PNGPREFIX_H - -/* - * This allows linking to multiple versions of libpng. This way clients can use a - * different version of libpng, if they desire, while SkCodec can use the version - * we test with. - */ - -#define png_sRGB_table skia_png_sRGB_table -#define png_sRGB_base skia_png_sRGB_base -#define png_sRGB_delta skia_png_sRGB_delta -#define png_zstream_error skia_png_zstream_error -#define png_free_buffer_list skia_png_free_buffer_list -#define png_fixed skia_png_fixed -#define png_user_version_check skia_png_user_version_check -#define png_malloc_base skia_png_malloc_base -#define png_malloc_array skia_png_malloc_array -#define png_realloc_array skia_png_realloc_array -#define png_create_png_struct skia_png_create_png_struct -#define png_destroy_png_struct skia_png_destroy_png_struct -#define png_free_jmpbuf skia_png_free_jmpbuf -#define png_zalloc skia_png_zalloc -#define png_zfree skia_png_zfree -#define png_default_read_data skia_png_default_read_data -#define png_push_fill_buffer skia_png_push_fill_buffer -#define png_default_write_data skia_png_default_write_data -#define png_default_flush skia_png_default_flush -#define png_reset_crc skia_png_reset_crc -#define png_write_data skia_png_write_data -#define png_read_sig skia_png_read_sig -#define png_read_chunk_header skia_png_read_chunk_header -#define png_read_data skia_png_read_data -#define png_crc_read skia_png_crc_read -#define png_crc_finish skia_png_crc_finish -#define png_crc_error skia_png_crc_error -#define png_calculate_crc skia_png_calculate_crc -#define png_flush skia_png_flush -#define png_write_IHDR skia_png_write_IHDR -#define png_write_PLTE skia_png_write_PLTE -#define png_compress_IDAT skia_png_compress_IDAT -#define png_write_IEND skia_png_write_IEND -#define png_write_gAMA_fixed skia_png_write_gAMA_fixed -#define png_write_sBIT skia_png_write_sBIT -#define png_write_cHRM_fixed skia_png_write_cHRM_fixed -#define png_write_sRGB skia_png_write_sRGB -#define png_write_iCCP skia_png_write_iCCP -#define png_write_sPLT skia_png_write_sPLT -#define png_write_tRNS skia_png_write_tRNS -#define png_write_bKGD skia_png_write_bKGD -#define png_write_hIST skia_png_write_hIST -#define png_write_tEXt skia_png_write_tEXt -#define png_write_zTXt skia_png_write_zTXt -#define png_write_iTXt skia_png_write_iTXt -#define png_set_text_2 skia_png_set_text_2 -#define png_write_oFFs skia_png_write_oFFs -#define png_write_pCAL skia_png_write_pCAL -#define png_write_pHYs skia_png_write_pHYs -#define png_write_tIME skia_png_write_tIME -#define png_write_sCAL_s skia_png_write_sCAL_s -#define png_write_finish_row skia_png_write_finish_row -#define png_write_start_row skia_png_write_start_row -#define png_combine_row skia_png_combine_row -#define png_do_read_interlace skia_png_do_read_interlace -#define png_do_write_interlace skia_png_do_write_interlace -#define png_read_filter_row skia_png_read_filter_row -#define png_read_filter_row_up_neon skia_png_read_filter_row_up_neon -#define png_read_filter_row_sub3_neon skia_png_read_filter_row_sub3_neon -#define png_read_filter_row_sub4_neon skia_png_read_filter_row_sub4_neon -#define png_read_filter_row_avg3_neon skia_png_read_filter_row_avg3_neon -#define png_read_filter_row_avg4_neon skia_png_read_filter_row_avg4_neon -#define png_read_filter_row_paeth3_neon skia_png_read_filter_row_paeth3_neon -#define png_read_filter_row_paeth4_neon skia_png_read_filter_row_paeth4_neon -#define png_read_filter_row_sub3_sse2 skia_png_read_filter_row_sub3_sse2 -#define png_read_filter_row_sub4_sse2 skia_png_read_filter_row_sub4_sse2 -#define png_read_filter_row_avg3_sse2 skia_png_read_filter_row_avg3_sse2 -#define png_read_filter_row_avg4_sse2 skia_png_read_filter_row_avg4_sse2 -#define png_read_filter_row_paeth3_sse2 skia_png_read_filter_row_paeth3_sse2 -#define png_read_filter_row_paeth4_sse2 skia_png_read_filter_row_paeth4_sse2 -#define png_write_find_filter skia_png_write_find_filter -#define png_read_IDAT_data skia_png_read_IDAT_data -#define png_read_finish_IDAT skia_png_read_finish_IDAT -#define png_read_finish_row skia_png_read_finish_row -#define png_read_start_row skia_png_read_start_row -#define png_read_transform_info skia_png_read_transform_info -#define png_do_read_filler skia_png_do_read_filler -#define png_do_read_swap_alpha skia_png_do_read_swap_alpha -#define png_do_write_swap_alpha skia_png_do_write_swap_alpha -#define png_do_read_invert_alpha skia_png_do_read_invert_alpha -#define png_do_write_invert_alpha skia_png_do_write_invert_alpha -#define png_do_strip_channel skia_png_do_strip_channel -#define png_do_swap skia_png_do_swap -#define png_do_packswap skia_png_do_packswap -#define png_do_rgb_to_gray skia_png_do_rgb_to_gray -#define png_do_gray_to_rgb skia_png_do_gray_to_rgb -#define png_do_unpack skia_png_do_unpack -#define png_do_unshift skia_png_do_unshift -#define png_do_invert skia_png_do_invert -#define png_do_scale_16_to_8 skia_png_do_scale_16_to_8 -#define png_do_chop skia_png_do_chop -#define png_do_quantize skia_png_do_quantize -#define png_do_bgr skia_png_do_bgr -#define png_do_pack skia_png_do_pack -#define png_do_shift skia_png_do_shift -#define png_do_compose skia_png_do_compose -#define png_do_gamma skia_png_do_gamma -#define png_do_encode_alpha skia_png_do_encode_alpha -#define png_do_expand_palette skia_png_do_expand_palette -#define png_do_expand skia_png_do_expand -#define png_do_expand_16 skia_png_do_expand_16 -#define png_handle_IHDR skia_png_handle_IHDR -#define png_handle_PLTE skia_png_handle_PLTE -#define png_handle_IEND skia_png_handle_IEND -#define png_handle_bKGD skia_png_handle_bKGD -#define png_handle_cHRM skia_png_handle_cHRM -#define png_handle_gAMA skia_png_handle_gAMA -#define png_handle_hIST skia_png_handle_hIST -#define png_handle_iCCP skia_png_handle_iCCP -#define png_handle_iTXt skia_png_handle_iTXt -#define png_handle_oFFs skia_png_handle_oFFs -#define png_handle_pCAL skia_png_handle_pCAL -#define png_handle_pHYs skia_png_handle_pHYs -#define png_handle_sBIT skia_png_handle_sBIT -#define png_handle_sCAL skia_png_handle_sCAL -#define png_handle_sPLT skia_png_handle_sPLT -#define png_handle_sRGB skia_png_handle_sRGB -#define png_handle_tEXt skia_png_handle_tEXt -#define png_handle_tIME skia_png_handle_tIME -#define png_handle_tRNS skia_png_handle_tRNS -#define png_handle_zTXt skia_png_handle_zTXt -#define png_check_chunk_name skia_png_check_chunk_name -#define png_handle_unknown skia_png_handle_unknown -#define png_chunk_unknown_handling skia_png_chunk_unknown_handling -#define png_do_read_transformations skia_png_do_read_transformations -#define png_do_write_transformations skia_png_do_write_transformations -#define png_init_read_transformations skia_png_init_read_transformations -#define png_push_read_chunk skia_png_push_read_chunk -#define png_push_read_sig skia_png_push_read_sig -#define png_push_check_crc skia_png_push_check_crc -#define png_push_crc_skip skia_png_push_crc_skip -#define png_push_crc_finish skia_png_push_crc_finish -#define png_push_save_buffer skia_png_push_save_buffer -#define png_push_restore_buffer skia_png_push_restore_buffer -#define png_push_read_IDAT skia_png_push_read_IDAT -#define png_process_IDAT_data skia_png_process_IDAT_data -#define png_push_process_row skia_png_push_process_row -#define png_push_handle_unknown skia_png_push_handle_unknown -#define png_push_have_info skia_png_push_have_info -#define png_push_have_end skia_png_push_have_end -#define png_push_have_row skia_png_push_have_row -#define png_push_read_end skia_png_push_read_end -#define png_process_some_data skia_png_process_some_data -#define png_read_push_finish_row skia_png_read_push_finish_row -#define png_push_handle_tEXt skia_png_push_handle_tEXt -#define png_push_read_tEXt skia_png_push_read_tEXt -#define png_push_handle_zTXt skia_png_push_handle_zTXt -#define png_push_read_zTXt skia_png_push_read_zTXt -#define png_push_handle_iTXt skia_png_push_handle_iTXt -#define png_push_read_iTXt skia_png_push_read_iTXt -#define png_do_read_intrapixel skia_png_do_read_intrapixel -#define png_do_write_intrapixel skia_png_do_write_intrapixel -#define png_colorspace_set_gamma skia_png_colorspace_set_gamma -#define png_colorspace_sync_info skia_png_colorspace_sync_info -#define png_colorspace_sync skia_png_colorspace_sync -#define png_colorspace_set_chromaticities skia_png_colorspace_set_chromaticities -#define png_colorspace_set_endpoints skia_png_colorspace_set_endpoints -#define png_colorspace_set_sRGB skia_png_colorspace_set_sRGB -#define png_colorspace_set_ICC skia_png_colorspace_set_ICC -#define png_icc_check_length skia_png_icc_check_length -#define png_icc_check_header skia_png_icc_check_header -#define png_icc_check_tag_table skia_png_icc_check_tag_table -#define png_icc_set_sRGB skia_png_icc_set_sRGB -#define png_colorspace_set_rgb_coefficients skia_png_colorspace_set_rgb_coefficients -#define png_check_IHDR skia_png_check_IHDR -#define png_do_check_palette_indexes skia_png_do_check_palette_indexes -#define png_fixed_error skia_png_fixed_error -#define png_safecat skia_png_safecat -#define png_format_number skia_png_format_number -#define png_warning_parameter skia_png_warning_parameter -#define png_warning_parameter_unsigned skia_png_warning_parameter_unsigned -#define png_warning_parameter_signed skia_png_warning_parameter_signed -#define png_formatted_warning skia_png_formatted_warning -#define png_app_warning skia_png_app_warning -#define png_app_error skia_png_app_error -#define png_chunk_report skia_png_chunk_report -#define png_ascii_from_fp skia_png_ascii_from_fp -#define png_ascii_from_fixed skia_png_ascii_from_fixed -#define png_check_fp_number skia_png_check_fp_number -#define png_check_fp_string skia_png_check_fp_string -#define png_muldiv skia_png_muldiv -#define png_muldiv_warn skia_png_muldiv_warn -#define png_reciprocal skia_png_reciprocal -#define png_reciprocal2 skia_png_reciprocal2 -#define png_gamma_significant skia_png_gamma_significant -#define png_gamma_correct skia_png_gamma_correct -#define png_gamma_16bit_correct skia_png_gamma_16bit_correct -#define png_gamma_8bit_correct skia_png_gamma_8bit_correct -#define png_destroy_gamma_table skia_png_destroy_gamma_table -#define png_build_gamma_table skia_png_build_gamma_table -#define png_safe_error skia_png_safe_error -#define png_safe_warning skia_png_safe_warning -#define png_safe_execute skia_png_safe_execute -#define png_image_error skia_png_image_error -#define png_access_version_number skia_png_access_version_number -#define png_build_grayscale_palette skia_png_build_grayscale_palette -#define png_convert_to_rfc1123 skia_png_convert_to_rfc1123 -#define png_convert_to_rfc1123_buffer skia_png_convert_to_rfc1123_buffer -#define png_create_info_struct skia_png_create_info_struct -#define png_data_freer skia_png_data_freer -#define png_destroy_info_struct skia_png_destroy_info_struct -#define png_free_data skia_png_free_data -#define png_get_copyright skia_png_get_copyright -#define png_get_header_ver skia_png_get_header_ver -#define png_get_header_version skia_png_get_header_version -#define png_get_io_ptr skia_png_get_io_ptr -#define png_get_libpng_ver skia_png_get_libpng_ver -#define png_handle_as_unknown skia_png_handle_as_unknown -#define png_image_free skia_png_image_free -#define png_info_init_3 skia_png_info_init_3 -#define png_init_io skia_png_init_io -#define png_reset_zstream skia_png_reset_zstream -#define png_save_int_32 skia_png_save_int_32 -#define png_set_option skia_png_set_option -#define png_set_sig_bytes skia_png_set_sig_bytes -#define png_sig_cmp skia_png_sig_cmp -#define png_benign_error skia_png_benign_error -#define png_chunk_benign_error skia_png_chunk_benign_error -#define png_chunk_error skia_png_chunk_error -#define png_chunk_warning skia_png_chunk_warning -#define png_error skia_png_error -#define png_get_error_ptr skia_png_get_error_ptr -#define png_longjmp skia_png_longjmp -#define png_set_error_fn skia_png_set_error_fn -#define png_set_longjmp_fn skia_png_set_longjmp_fn -#define png_warning skia_png_warning -#define png_get_bit_depth skia_png_get_bit_depth -#define png_get_bKGD skia_png_get_bKGD -#define png_get_channels skia_png_get_channels -#define png_get_cHRM skia_png_get_cHRM -#define png_get_cHRM_fixed skia_png_get_cHRM_fixed -#define png_get_cHRM_XYZ skia_png_get_cHRM_XYZ -#define png_get_cHRM_XYZ_fixed skia_png_get_cHRM_XYZ_fixed -#define png_get_chunk_cache_max skia_png_get_chunk_cache_max -#define png_get_chunk_malloc_max skia_png_get_chunk_malloc_max -#define png_get_color_type skia_png_get_color_type -#define png_get_compression_buffer_size skia_png_get_compression_buffer_size -#define png_get_compression_type skia_png_get_compression_type -#define png_get_filter_type skia_png_get_filter_type -#define png_get_gAMA skia_png_get_gAMA -#define png_get_gAMA_fixed skia_png_get_gAMA_fixed -#define png_get_hIST skia_png_get_hIST -#define png_get_iCCP skia_png_get_iCCP -#define png_get_IHDR skia_png_get_IHDR -#define png_get_image_height skia_png_get_image_height -#define png_get_image_width skia_png_get_image_width -#define png_get_interlace_type skia_png_get_interlace_type -#define png_get_io_chunk_type skia_png_get_io_chunk_type -#define png_get_io_state skia_png_get_io_state -#define png_get_oFFs skia_png_get_oFFs -#define png_get_palette_max skia_png_get_palette_max -#define png_get_pCAL skia_png_get_pCAL -#define png_get_pHYs skia_png_get_pHYs -#define png_get_pHYs_dpi skia_png_get_pHYs_dpi -#define png_get_pixel_aspect_ratio skia_png_get_pixel_aspect_ratio -#define png_get_pixel_aspect_ratio_fixed skia_png_get_pixel_aspect_ratio_fixed -#define png_get_pixels_per_inch skia_png_get_pixels_per_inch -#define png_get_pixels_per_meter skia_png_get_pixels_per_meter -#define png_get_PLTE skia_png_get_PLTE -#define png_get_rgb_to_gray_status skia_png_get_rgb_to_gray_status -#define png_get_rowbytes skia_png_get_rowbytes -#define png_get_rows skia_png_get_rows -#define png_get_sBIT skia_png_get_sBIT -#define png_get_sCAL skia_png_get_sCAL -#define png_get_sCAL_fixed skia_png_get_sCAL_fixed -#define png_get_sCAL_s skia_png_get_sCAL_s -#define png_get_signature skia_png_get_signature -#define png_get_sPLT skia_png_get_sPLT -#define png_get_sRGB skia_png_get_sRGB -#define png_get_text skia_png_get_text -#define png_get_tIME skia_png_get_tIME -#define png_get_tRNS skia_png_get_tRNS -#define png_get_unknown_chunks skia_png_get_unknown_chunks -#define png_get_user_chunk_ptr skia_png_get_user_chunk_ptr -#define png_get_user_height_max skia_png_get_user_height_max -#define png_get_user_width_max skia_png_get_user_width_max -#define png_get_valid skia_png_get_valid -#define png_get_x_offset_inches skia_png_get_x_offset_inches -#define png_get_x_offset_inches_fixed skia_png_get_x_offset_inches_fixed -#define png_get_x_offset_microns skia_png_get_x_offset_microns -#define png_get_x_offset_pixels skia_png_get_x_offset_pixels -#define png_get_x_pixels_per_inch skia_png_get_x_pixels_per_inch -#define png_get_x_pixels_per_meter skia_png_get_x_pixels_per_meter -#define png_get_y_offset_inches skia_png_get_y_offset_inches -#define png_get_y_offset_inches_fixed skia_png_get_y_offset_inches_fixed -#define png_get_y_offset_microns skia_png_get_y_offset_microns -#define png_get_y_offset_pixels skia_png_get_y_offset_pixels -#define png_get_y_pixels_per_inch skia_png_get_y_pixels_per_inch -#define png_get_y_pixels_per_meter skia_png_get_y_pixels_per_meter -#define png_calloc skia_png_calloc -#define png_free skia_png_free -#define png_free_default skia_png_free_default -#define png_get_mem_ptr skia_png_get_mem_ptr -#define png_malloc skia_png_malloc -#define png_malloc_default skia_png_malloc_default -#define png_malloc_warn skia_png_malloc_warn -#define png_set_mem_fn skia_png_set_mem_fn -#define png_get_progressive_ptr skia_png_get_progressive_ptr -#define png_process_data skia_png_process_data -#define png_process_data_pause skia_png_process_data_pause -#define png_process_data_skip skia_png_process_data_skip -#define png_progressive_combine_row skia_png_progressive_combine_row -#define png_set_progressive_read_fn skia_png_set_progressive_read_fn -#define png_create_read_struct skia_png_create_read_struct -#define png_create_read_struct_2 skia_png_create_read_struct_2 -#define png_destroy_read_struct skia_png_destroy_read_struct -#define png_image_begin_read_from_file skia_png_image_begin_read_from_file -#define png_image_begin_read_from_memory skia_png_image_begin_read_from_memory -#define png_image_begin_read_from_stdio skia_png_image_begin_read_from_stdio -#define png_image_finish_read skia_png_image_finish_read -#define png_read_end skia_png_read_end -#define png_read_image skia_png_read_image -#define png_read_info skia_png_read_info -#define png_read_png skia_png_read_png -#define png_read_row skia_png_read_row -#define png_read_rows skia_png_read_rows -#define png_read_update_info skia_png_read_update_info -#define png_set_read_status_fn skia_png_set_read_status_fn -#define png_start_read_image skia_png_start_read_image -#define png_set_read_fn skia_png_set_read_fn -#define png_set_alpha_mode skia_png_set_alpha_mode -#define png_set_alpha_mode_fixed skia_png_set_alpha_mode_fixed -#define png_set_background skia_png_set_background -#define png_set_background_fixed skia_png_set_background_fixed -#define png_set_crc_action skia_png_set_crc_action -#define png_set_expand skia_png_set_expand -#define png_set_expand_16 skia_png_set_expand_16 -#define png_set_expand_gray_1_2_4_to_8 skia_png_set_expand_gray_1_2_4_to_8 -#define png_set_gamma skia_png_set_gamma -#define png_set_gamma_fixed skia_png_set_gamma_fixed -#define png_set_gray_to_rgb skia_png_set_gray_to_rgb -#define png_set_palette_to_rgb skia_png_set_palette_to_rgb -#define png_set_quantize skia_png_set_quantize -#define png_set_read_user_transform_fn skia_png_set_read_user_transform_fn -#define png_set_rgb_to_gray skia_png_set_rgb_to_gray -#define png_set_rgb_to_gray_fixed skia_png_set_rgb_to_gray_fixed -#define png_set_scale_16 skia_png_set_scale_16 -#define png_set_strip_16 skia_png_set_strip_16 -#define png_set_strip_alpha skia_png_set_strip_alpha -#define png_set_tRNS_to_alpha skia_png_set_tRNS_to_alpha -#define png_get_int_32 skia_png_get_int_32 -#define png_get_uint_16 skia_png_get_uint_16 -#define png_get_uint_31 skia_png_get_uint_31 -#define png_get_uint_32 skia_png_get_uint_32 -#define png_permit_mng_features skia_png_permit_mng_features -#define png_set_benign_errors skia_png_set_benign_errors -#define png_set_bKGD skia_png_set_bKGD -#define png_set_check_for_invalid_index skia_png_set_check_for_invalid_index -#define png_set_cHRM skia_png_set_cHRM -#define png_set_cHRM_fixed skia_png_set_cHRM_fixed -#define png_set_cHRM_XYZ skia_png_set_cHRM_XYZ -#define png_set_cHRM_XYZ_fixed skia_png_set_cHRM_XYZ_fixed -#define png_set_chunk_cache_max skia_png_set_chunk_cache_max -#define png_set_chunk_malloc_max skia_png_set_chunk_malloc_max -#define png_set_compression_buffer_size skia_png_set_compression_buffer_size -#define png_set_gAMA skia_png_set_gAMA -#define png_set_gAMA_fixed skia_png_set_gAMA_fixed -#define png_set_hIST skia_png_set_hIST -#define png_set_iCCP skia_png_set_iCCP -#define png_set_IHDR skia_png_set_IHDR -#define png_set_invalid skia_png_set_invalid -#define png_set_keep_unknown_chunks skia_png_set_keep_unknown_chunks -#define png_set_oFFs skia_png_set_oFFs -#define png_set_pCAL skia_png_set_pCAL -#define png_set_pHYs skia_png_set_pHYs -#define png_set_PLTE skia_png_set_PLTE -#define png_set_read_user_chunk_fn skia_png_set_read_user_chunk_fn -#define png_set_rows skia_png_set_rows -#define png_set_sBIT skia_png_set_sBIT -#define png_set_sCAL skia_png_set_sCAL -#define png_set_sCAL_fixed skia_png_set_sCAL_fixed -#define png_set_sCAL_s skia_png_set_sCAL_s -#define png_set_sPLT skia_png_set_sPLT -#define png_set_sRGB skia_png_set_sRGB -#define png_set_sRGB_gAMA_and_cHRM skia_png_set_sRGB_gAMA_and_cHRM -#define png_set_text skia_png_set_text -#define png_set_tIME skia_png_set_tIME -#define png_set_tRNS skia_png_set_tRNS -#define png_set_unknown_chunk_location skia_png_set_unknown_chunk_location -#define png_set_unknown_chunks skia_png_set_unknown_chunks -#define png_set_user_limits skia_png_set_user_limits -#define png_get_current_pass_number skia_png_get_current_pass_number -#define png_get_current_row_number skia_png_get_current_row_number -#define png_get_user_transform_ptr skia_png_get_user_transform_ptr -#define png_set_add_alpha skia_png_set_add_alpha -#define png_set_bgr skia_png_set_bgr -#define png_set_filler skia_png_set_filler -#define png_set_interlace_handling skia_png_set_interlace_handling -#define png_set_invert_alpha skia_png_set_invert_alpha -#define png_set_invert_mono skia_png_set_invert_mono -#define png_set_packing skia_png_set_packing -#define png_set_packswap skia_png_set_packswap -#define png_set_shift skia_png_set_shift -#define png_set_swap skia_png_set_swap -#define png_set_swap_alpha skia_png_set_swap_alpha -#define png_set_user_transform_info skia_png_set_user_transform_info -#define png_set_write_fn skia_png_set_write_fn -#define png_convert_from_struct_tm skia_png_convert_from_struct_tm -#define png_convert_from_time_t skia_png_convert_from_time_t -#define png_create_write_struct skia_png_create_write_struct -#define png_create_write_struct_2 skia_png_create_write_struct_2 -#define png_destroy_write_struct skia_png_destroy_write_struct -#define png_image_write_to_file skia_png_image_write_to_file -#define png_image_write_to_stdio skia_png_image_write_to_stdio -#define png_set_compression_level skia_png_set_compression_level -#define png_set_compression_mem_level skia_png_set_compression_mem_level -#define png_set_compression_method skia_png_set_compression_method -#define png_set_compression_strategy skia_png_set_compression_strategy -#define png_set_compression_window_bits skia_png_set_compression_window_bits -#define png_set_filter skia_png_set_filter -#define png_set_filter_heuristics skia_png_set_filter_heuristics -#define png_set_filter_heuristics_fixed skia_png_set_filter_heuristics_fixed -#define png_set_flush skia_png_set_flush -#define png_set_text_compression_level skia_png_set_text_compression_level -#define png_set_text_compression_mem_level skia_png_set_text_compression_mem_level -#define png_set_text_compression_method skia_png_set_text_compression_method -#define png_set_text_compression_strategy skia_png_set_text_compression_strategy -#define png_set_text_compression_window_bits skia_png_set_text_compression_window_bits -#define png_set_write_status_fn skia_png_set_write_status_fn -#define png_set_write_user_transform_fn skia_png_set_write_user_transform_fn -#define png_write_end skia_png_write_end -#define png_write_flush skia_png_write_flush -#define png_write_image skia_png_write_image -#define png_write_info skia_png_write_info -#define png_write_info_before_PLTE skia_png_write_info_before_PLTE -#define png_write_png skia_png_write_png -#define png_write_row skia_png_write_row -#define png_write_rows skia_png_write_rows -#define png_save_uint_16 skia_png_save_uint_16 -#define png_save_uint_32 skia_png_save_uint_32 -#define png_write_chunk skia_png_write_chunk -#define png_write_chunk_data skia_png_write_chunk_data -#define png_write_chunk_start skia_png_write_chunk_start -#define png_write_chunk_end skia_png_write_chunk_end -#define png_write_sig skia_png_write_sig -#define png_init_filter_functions_neon skia_png_init_filter_functions_neon -#define png_init_filter_functions_sse2 skia_png_init_filter_functions_sse2 - -#endif // PNGPREFIX_H diff --git a/third_party/libpng/pngpriv.h b/third_party/libpng/pngpriv.h deleted file mode 100644 index 8893f18b97..0000000000 --- a/third_party/libpng/pngpriv.h +++ /dev/null @@ -1,1983 +0,0 @@ - -/* pngpriv.h - private declarations for use inside libpng - * - * Last changed in libpng 1.6.22 [(PENDING RELEASE)] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -/* The symbols declared in this file (including the functions declared - * as extern) are PRIVATE. They are not part of the libpng public - * interface, and are not recommended for use by regular applications. - * Some of them may become public in the future; others may stay private, - * change in an incompatible way, or even disappear. - * Although the libpng users are not forbidden to include this header, - * they should be well aware of the issues that may arise from doing so. - */ - -#ifndef PNGPRIV_H -#define PNGPRIV_H - -/* Feature Test Macros. The following are defined here to ensure that correctly - * implemented libraries reveal the APIs libpng needs to build and hide those - * that are not needed and potentially damaging to the compilation. - * - * Feature Test Macros must be defined before any system header is included (see - * POSIX 1003.1 2.8.2 "POSIX Symbols." - * - * These macros only have an effect if the operating system supports either - * POSIX 1003.1 or C99, or both. On other operating systems (particularly - * Windows/Visual Studio) there is no effect; the OS specific tests below are - * still required (as of 2011-05-02.) - */ -#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */ - -#ifndef PNG_VERSION_INFO_ONLY -/* Standard library headers not required by png.h: */ -# include <stdlib.h> -# include <string.h> -#endif - -#define PNGLIB_BUILD /*libpng is being built, not used*/ - -/* If HAVE_CONFIG_H is defined during the build then the build system must - * provide an appropriate "config.h" file on the include path. The header file - * must provide definitions as required below (search for "HAVE_CONFIG_H"); - * see configure.ac for more details of the requirements. The macro - * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on - * 'configure'; define this macro to prevent the configure build including the - * configure generated config.h. Libpng is expected to compile without *any* - * special build system support on a reasonably ANSI-C compliant system. - */ -#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) -# include <config.h> - - /* Pick up the definition of 'restrict' from config.h if it was read: */ -# define PNG_RESTRICT restrict -#endif - -/* To support symbol prefixing it is necessary to know *before* including png.h - * whether the fixed point (and maybe other) APIs are exported, because if they - * are not internal definitions may be required. This is handled below just - * before png.h is included, but load the configuration now if it is available. - */ -#ifndef PNGLCONF_H -# include "pnglibconf.h" -#endif - -/* Local renames may change non-exported API functions from png.h */ -#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H) -# include "pngprefix.h" -#endif - -#ifdef PNG_USER_CONFIG -# include "pngusr.h" - /* These should have been defined in pngusr.h */ -# ifndef PNG_USER_PRIVATEBUILD -# define PNG_USER_PRIVATEBUILD "Custom libpng build" -# endif -# ifndef PNG_USER_DLLFNAME_POSTFIX -# define PNG_USER_DLLFNAME_POSTFIX "Cb" -# endif -#endif - -/* Compile time options. - * ===================== - * In a multi-arch build the compiler may compile the code several times for the - * same object module, producing different binaries for different architectures. - * When this happens configure-time setting of the target host options cannot be - * done and this interferes with the handling of the ARM NEON optimizations, and - * possibly other similar optimizations. Put additional tests here; in general - * this is needed when the same option can be changed at both compile time and - * run time depending on the target OS (i.e. iOS vs Android.) - * - * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because - * this is not possible with certain compilers (Oracle SUN OS CC), as a result - * it is necessary to ensure that all extern functions that *might* be used - * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__ - * below is one example of this behavior because it is controlled by the - * presence or not of -mfpu=neon on the GCC command line, it is possible to do - * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely - * do this. - */ -#ifndef PNG_ARM_NEON_OPT - /* ARM NEON optimizations are being controlled by the compiler settings, - * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon - * with GCC) then the compiler will define __ARM_NEON__ and we can rely - * unconditionally on NEON instructions not crashing, otherwise we must - * disable use of NEON instructions. - * - * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they - * can only be turned on automatically if that is supported too. If - * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail - * to compile with an appropriate #error if ALIGNED_MEMORY has been turned - * off. - * - * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated - * __ARM_NEON__, so we check both variants. - * - * To disable ARM_NEON optimizations entirely, and skip compiling the - * associated assembler code, pass --enable-arm-neon=no to configure - * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS. - */ -# if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \ - defined(PNG_ALIGNED_MEMORY_SUPPORTED) -# define PNG_ARM_NEON_OPT 2 -# else -# define PNG_ARM_NEON_OPT 0 -# endif -#endif - -#if PNG_ARM_NEON_OPT > 0 - /* NEON optimizations are to be at least considered by libpng, so enable the - * callbacks to do this. - */ -# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon - - /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used - * if possible - if __ARM_NEON__ is set and the compiler version is not known - * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can - * be: - * - * 1 The intrinsics code (the default with __ARM_NEON__) - * 2 The hand coded assembler (the default without __ARM_NEON__) - * - * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however - * this is *NOT* supported and may cease to work even after a minor revision - * to libpng. It *is* valid to do this for testing purposes, e.g. speed - * testing or a new compiler, but the results should be communicated to the - * libpng implementation list for incorporation in the next minor release. - */ -# ifndef PNG_ARM_NEON_IMPLEMENTATION -# if defined(__ARM_NEON__) || defined(__ARM_NEON) -# if defined(__clang__) - /* At present it is unknown by the libpng developers which versions - * of clang support the intrinsics, however some or perhaps all - * versions do not work with the assembler so this may be - * irrelevant, so just use the default (do nothing here.) - */ -# elif defined(__GNUC__) - /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to - * work, so if this *is* GCC, or G++, look for a version >4.5 - */ -# if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6) -# define PNG_ARM_NEON_IMPLEMENTATION 2 -# endif /* no GNUC support */ -# endif /* __GNUC__ */ -# else /* !defined __ARM_NEON__ */ - /* The 'intrinsics' code simply won't compile without this -mfpu=neon: - */ -# define PNG_ARM_NEON_IMPLEMENTATION 2 -# endif /* __ARM_NEON__ */ -# endif /* !PNG_ARM_NEON_IMPLEMENTATION */ - -# ifndef PNG_ARM_NEON_IMPLEMENTATION - /* Use the intrinsics code by default. */ -# define PNG_ARM_NEON_IMPLEMENTATION 1 -# endif -#endif /* PNG_ARM_NEON_OPT > 0 */ - -#ifndef PNG_INTEL_SSE_OPT -# ifdef PNG_INTEL_SSE - /* Only check for SSE if the build configuration has been modified to - * enable SSE optimizations. This means that these optimizations will - * be off by default. See contrib/intel for more details. - */ -# if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \ - defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ - (defined(_M_IX86_FP) && _M_IX86_FP >= 2) -# define PNG_INTEL_SSE_OPT 1 -# endif -# endif -#endif - -#if PNG_INTEL_SSE_OPT > 0 -# ifndef PNG_INTEL_SSE_IMPLEMENTATION -# if defined(__SSE4_1__) || defined(__AVX__) - /* We are not actually using AVX, but checking for AVX is the best - way we can detect SSE4.1 and SSSE3 on MSVC. - */ -# define PNG_INTEL_SSE_IMPLEMENTATION 3 -# elif defined(__SSSE3__) -# define PNG_INTEL_SSE_IMPLEMENTATION 2 -# elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ - (defined(_M_IX86_FP) && _M_IX86_FP >= 2) -# define PNG_INTEL_SSE_IMPLEMENTATION 1 -# else -# define PNG_INTEL_SSE_IMPLEMENTATION 0 -# endif -# endif - -# if PNG_INTEL_SSE_IMPLEMENTATION > 0 -# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2 -# endif -#endif - -/* Is this a build of a DLL where compilation of the object modules requires - * different preprocessor settings to those required for a simple library? If - * so PNG_BUILD_DLL must be set. - * - * If libpng is used inside a DLL but that DLL does not export the libpng APIs - * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a - * static library of libpng then link the DLL against that. - */ -#ifndef PNG_BUILD_DLL -# ifdef DLL_EXPORT - /* This is set by libtool when files are compiled for a DLL; libtool - * always compiles twice, even on systems where it isn't necessary. Set - * PNG_BUILD_DLL in case it is necessary: - */ -# define PNG_BUILD_DLL -# else -# ifdef _WINDLL - /* This is set by the Microsoft Visual Studio IDE in projects that - * build a DLL. It can't easily be removed from those projects (it - * isn't visible in the Visual Studio UI) so it is a fairly reliable - * indication that PNG_IMPEXP needs to be set to the DLL export - * attributes. - */ -# define PNG_BUILD_DLL -# else -# ifdef __DLL__ - /* This is set by the Borland C system when compiling for a DLL - * (as above.) - */ -# define PNG_BUILD_DLL -# else - /* Add additional compiler cases here. */ -# endif -# endif -# endif -#endif /* Setting PNG_BUILD_DLL if required */ - -/* See pngconf.h for more details: the builder of the library may set this on - * the command line to the right thing for the specific compilation system or it - * may be automagically set above (at present we know of no system where it does - * need to be set on the command line.) - * - * PNG_IMPEXP must be set here when building the library to prevent pngconf.h - * setting it to the "import" setting for a DLL build. - */ -#ifndef PNG_IMPEXP -# ifdef PNG_BUILD_DLL -# define PNG_IMPEXP PNG_DLL_EXPORT -# else - /* Not building a DLL, or the DLL doesn't require specific export - * definitions. - */ -# define PNG_IMPEXP -# endif -#endif - -/* No warnings for private or deprecated functions in the build: */ -#ifndef PNG_DEPRECATED -# define PNG_DEPRECATED -#endif -#ifndef PNG_PRIVATE -# define PNG_PRIVATE -#endif - -/* Symbol preprocessing support. - * - * To enable listing global, but internal, symbols the following macros should - * always be used to declare an extern data or function object in this file. - */ -#ifndef PNG_INTERNAL_DATA -# define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array -#endif - -#ifndef PNG_INTERNAL_FUNCTION -# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\ - PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes) -#endif - -#ifndef PNG_INTERNAL_CALLBACK -# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\ - PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\ - PNG_EMPTY attributes) -#endif - -/* If floating or fixed point APIs are disabled they may still be compiled - * internally. To handle this make sure they are declared as the appropriate - * internal extern function (otherwise the symbol prefixing stuff won't work and - * the functions will be used without definitions.) - * - * NOTE: although all the API functions are declared here they are not all - * actually built! Because the declarations are still made it is necessary to - * fake out types that they depend on. - */ -#ifndef PNG_FP_EXPORT -# ifndef PNG_FLOATING_POINT_SUPPORTED -# define PNG_FP_EXPORT(ordinal, type, name, args)\ - PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY); -# ifndef PNG_VERSION_INFO_ONLY - typedef struct png_incomplete png_double; - typedef png_double* png_doublep; - typedef const png_double* png_const_doublep; - typedef png_double** png_doublepp; -# endif -# endif -#endif -#ifndef PNG_FIXED_EXPORT -# ifndef PNG_FIXED_POINT_SUPPORTED -# define PNG_FIXED_EXPORT(ordinal, type, name, args)\ - PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY); -# endif -#endif - -#include "png.h" - -/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */ -#ifndef PNG_DLL_EXPORT -# define PNG_DLL_EXPORT -#endif - -/* This is a global switch to set the compilation for an installed system - * (a release build). It can be set for testing debug builds to ensure that - * they will compile when the build type is switched to RC or STABLE, the - * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS - * with either: - * - * -DPNG_RELEASE_BUILD Turns on the release compile path - * -DPNG_RELEASE_BUILD=0 Turns it off - * or in your pngusr.h with - * #define PNG_RELEASE_BUILD=1 Turns on the release compile path - * #define PNG_RELEASE_BUILD=0 Turns it off - */ -#ifndef PNG_RELEASE_BUILD -# define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC) -#endif - -/* SECURITY and SAFETY: - * - * libpng is built with support for internal limits on image dimensions and - * memory usage. These are documented in scripts/pnglibconf.dfa of the - * source and recorded in the machine generated header file pnglibconf.h. - */ - -/* If you are running on a machine where you cannot allocate more - * than 64K of memory at once, uncomment this. While libpng will not - * normally need that much memory in a chunk (unless you load up a very - * large file), zlib needs to know how big of a chunk it can use, and - * libpng thus makes sure to check any memory allocation to verify it - * will fit into memory. - * - * zlib provides 'MAXSEG_64K' which, if defined, indicates the - * same limit and pngconf.h (already included) sets the limit - * if certain operating systems are detected. - */ -#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) -# define PNG_MAX_MALLOC_64K -#endif - -#ifndef PNG_UNUSED -/* Unused formal parameter warnings are silenced using the following macro - * which is expected to have no bad effects on performance (optimizing - * compilers will probably remove it entirely). Note that if you replace - * it with something other than whitespace, you must include the terminating - * semicolon. - */ -# define PNG_UNUSED(param) (void)param; -#endif - -/* Just a little check that someone hasn't tried to define something - * contradictory. - */ -#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K) -# undef PNG_ZBUF_SIZE -# define PNG_ZBUF_SIZE 65536L -#endif - -/* If warnings or errors are turned off the code is disabled or redirected here. - * From 1.5.4 functions have been added to allow very limited formatting of - * error and warning messages - this code will also be disabled here. - */ -#ifdef PNG_WARNINGS_SUPPORTED -# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p; -#else -# define png_warning_parameter(p,number,string) ((void)0) -# define png_warning_parameter_unsigned(p,number,format,value) ((void)0) -# define png_warning_parameter_signed(p,number,format,value) ((void)0) -# define png_formatted_warning(pp,p,message) ((void)(pp)) -# define PNG_WARNING_PARAMETERS(p) -#endif -#ifndef PNG_ERROR_TEXT_SUPPORTED -# define png_fixed_error(s1,s2) png_err(s1) -#endif - -/* C allows up-casts from (void*) to any pointer and (const void*) to any - * pointer to a const object. C++ regards this as a type error and requires an - * explicit, static, cast and provides the static_cast<> rune to ensure that - * const is not cast away. - */ -#ifdef __cplusplus -# define png_voidcast(type, value) static_cast<type>(value) -# define png_constcast(type, value) const_cast<type>(value) -# define png_aligncast(type, value) \ - static_cast<type>(static_cast<void*>(value)) -# define png_aligncastconst(type, value) \ - static_cast<type>(static_cast<const void*>(value)) -#else -# define png_voidcast(type, value) (value) -# define png_constcast(type, value) ((type)(value)) -# define png_aligncast(type, value) ((void*)(value)) -# define png_aligncastconst(type, value) ((const void*)(value)) -#endif /* __cplusplus */ - -/* Some fixed point APIs are still required even if not exported because - * they get used by the corresponding floating point APIs. This magic - * deals with this: - */ -#ifdef PNG_FIXED_POINT_SUPPORTED -# define PNGFAPI PNGAPI -#else -# define PNGFAPI /* PRIVATE */ -#endif - -#ifndef PNG_VERSION_INFO_ONLY -/* Other defines specific to compilers can go here. Try to keep - * them inside an appropriate ifdef/endif pair for portability. - */ -#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\ - defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) - /* png.c requires the following ANSI-C constants if the conversion of - * floating point to ASCII is implemented therein: - * - * DBL_DIG Maximum number of decimal digits (can be set to any constant) - * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value) - * DBL_MAX Maximum floating point number (can be set to an arbitrary value) - */ -# include <float.h> - -# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \ - defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC) - /* We need to check that <math.h> hasn't already been included earlier - * as it seems it doesn't agree with <fp.h>, yet we should really use - * <fp.h> if possible. - */ -# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__) -# include <fp.h> -# endif -# else -# include <math.h> -# endif -# if defined(_AMIGA) && defined(__SASC) && defined(_M68881) - /* Amiga SAS/C: We must include builtin FPU functions when compiling using - * MATH=68881 - */ -# include <m68881.h> -# endif -#endif - -/* This provides the non-ANSI (far) memory allocation routines. */ -#if defined(__TURBOC__) && defined(__MSDOS__) -# include <mem.h> -# include <alloc.h> -#endif - -#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \ - defined(_WIN32) || defined(__WIN32__) -# include <windows.h> /* defines _WINDOWS_ macro */ -#endif -#endif /* PNG_VERSION_INFO_ONLY */ - -/* Moved here around 1.5.0beta36 from pngconf.h */ -/* Users may want to use these so they are not private. Any library - * functions that are passed far data must be model-independent. - */ - -/* Memory model/platform independent fns */ -#ifndef PNG_ABORT -# ifdef _WINDOWS_ -# define PNG_ABORT() ExitProcess(0) -# else -# define PNG_ABORT() abort() -# endif -#endif - -/* These macros may need to be architecture dependent. */ -#define PNG_ALIGN_NONE 0 /* do not use data alignment */ -#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */ -#ifdef offsetof -# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */ -#else -# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */ -#endif -#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */ - -#ifndef PNG_ALIGN_TYPE - /* Default to using aligned access optimizations and requiring alignment to a - * multiple of the data type size. Override in a compiler specific fashion - * if necessary by inserting tests here: - */ -# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE -#endif - -#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE - /* This is used because in some compiler implementations non-aligned - * structure members are supported, so the offsetof approach below fails. - * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access - * is good for performance. Do not do this unless you have tested the result - * and understand it. - */ -# define png_alignof(type) (sizeof (type)) -#else -# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET -# define png_alignof(type) offsetof(struct{char c; type t;}, t) -# else -# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS -# define png_alignof(type) (1) -# endif - /* Else leave png_alignof undefined to prevent use thereof */ -# endif -#endif - -/* This implicitly assumes alignment is always to a power of 2. */ -#ifdef png_alignof -# define png_isaligned(ptr, type)\ - ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0) -#else -# define png_isaligned(ptr, type) 0 -#endif - -/* End of memory model/platform independent support */ -/* End of 1.5.0beta36 move from pngconf.h */ - -/* CONSTANTS and UTILITY MACROS - * These are used internally by libpng and not exposed in the API - */ - -/* Various modes of operation. Note that after an init, mode is set to - * zero automatically when the structure is created. Three of these - * are defined in png.h because they need to be visible to applications - * that call png_set_unknown_chunk(). - */ -/* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */ -/* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */ -#define PNG_HAVE_IDAT 0x04 -/* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */ -#define PNG_HAVE_IEND 0x10 - /* 0x20 (unused) */ - /* 0x40 (unused) */ - /* 0x80 (unused) */ -#define PNG_HAVE_CHUNK_HEADER 0x100 -#define PNG_WROTE_tIME 0x200 -#define PNG_WROTE_INFO_BEFORE_PLTE 0x400 -#define PNG_BACKGROUND_IS_GRAY 0x800 -#define PNG_HAVE_PNG_SIGNATURE 0x1000 -#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */ - /* 0x4000 (unused) */ -#define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */ - -/* Flags for the transformations the PNG library does on the image data */ -#define PNG_BGR 0x0001 -#define PNG_INTERLACE 0x0002 -#define PNG_PACK 0x0004 -#define PNG_SHIFT 0x0008 -#define PNG_SWAP_BYTES 0x0010 -#define PNG_INVERT_MONO 0x0020 -#define PNG_QUANTIZE 0x0040 -#define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */ -#define PNG_BACKGROUND_EXPAND 0x0100 -#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */ -#define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */ -#define PNG_RGBA 0x0800 -#define PNG_EXPAND 0x1000 -#define PNG_GAMMA 0x2000 -#define PNG_GRAY_TO_RGB 0x4000 -#define PNG_FILLER 0x8000 -#define PNG_PACKSWAP 0x10000 -#define PNG_SWAP_ALPHA 0x20000 -#define PNG_STRIP_ALPHA 0x40000 -#define PNG_INVERT_ALPHA 0x80000 -#define PNG_USER_TRANSFORM 0x100000 -#define PNG_RGB_TO_GRAY_ERR 0x200000 -#define PNG_RGB_TO_GRAY_WARN 0x400000 -#define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */ -#define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */ -#define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */ -#define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */ -#define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */ - /* 0x8000000 unused */ - /* 0x10000000 unused */ - /* 0x20000000 unused */ - /* 0x40000000 unused */ -/* Flags for png_create_struct */ -#define PNG_STRUCT_PNG 0x0001 -#define PNG_STRUCT_INFO 0x0002 - -/* Flags for the png_ptr->flags rather than declaring a byte for each one */ -#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001 -#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002 /* Added to libpng-1.6.0 */ - /* 0x0004 unused */ -#define PNG_FLAG_ZSTREAM_ENDED 0x0008 /* Added to libpng-1.6.0 */ - /* 0x0010 unused */ - /* 0x0020 unused */ -#define PNG_FLAG_ROW_INIT 0x0040 -#define PNG_FLAG_FILLER_AFTER 0x0080 -#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100 -#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200 -#define PNG_FLAG_CRC_CRITICAL_USE 0x0400 -#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800 -#define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */ -#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */ -#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */ -/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 */ -/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 */ -#define PNG_FLAG_LIBRARY_MISMATCH 0x20000 -#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000 -#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000 -#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */ -#define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */ -#define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */ - /* 0x800000 unused */ - /* 0x1000000 unused */ - /* 0x2000000 unused */ - /* 0x4000000 unused */ - /* 0x8000000 unused */ - /* 0x10000000 unused */ - /* 0x20000000 unused */ - /* 0x40000000 unused */ - -#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \ - PNG_FLAG_CRC_ANCILLARY_NOWARN) - -#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \ - PNG_FLAG_CRC_CRITICAL_IGNORE) - -#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \ - PNG_FLAG_CRC_CRITICAL_MASK) - -/* Save typing and make code easier to understand */ - -#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \ - abs((int)((c1).green) - (int)((c2).green)) + \ - abs((int)((c1).blue) - (int)((c2).blue))) - -/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255 - * by dividing by 257 *with rounding*. This macro is exact for the given range. - * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the - * macro were established by experiment (modifying the added value). The macro - * has a second variant that takes a value already scaled by 255 and divides by - * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it - * only gives off-by-one errors and only for 0.5% (1 in 200) of the values. - */ -#define PNG_DIV65535(v24) (((v24) + 32895) >> 16) -#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255) - -/* Added to libpng-1.2.6 JB */ -#define PNG_ROWBYTES(pixel_bits, width) \ - ((pixel_bits) >= 8 ? \ - ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \ - (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) ) - -/* PNG_OUT_OF_RANGE returns true if value is outside the range - * ideal-delta..ideal+delta. Each argument is evaluated twice. - * "ideal" and "delta" should be constants, normally simple - * integers, "value" a variable. Added to libpng-1.2.6 JB - */ -#define PNG_OUT_OF_RANGE(value, ideal, delta) \ - ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) ) - -/* Conversions between fixed and floating point, only defined if - * required (to make sure the code doesn't accidentally use float - * when it is supposedly disabled.) - */ -#ifdef PNG_FLOATING_POINT_SUPPORTED -/* The floating point conversion can't overflow, though it can and - * does lose accuracy relative to the original fixed point value. - * In practice this doesn't matter because png_fixed_point only - * stores numbers with very low precision. The png_ptr and s - * arguments are unused by default but are there in case error - * checking becomes a requirement. - */ -#define png_float(png_ptr, fixed, s) (.00001 * (fixed)) - -/* The fixed point conversion performs range checking and evaluates - * its argument multiple times, so must be used with care. The - * range checking uses the PNG specification values for a signed - * 32-bit fixed point value except that the values are deliberately - * rounded-to-zero to an integral value - 21474 (21474.83 is roughly - * (2^31-1) * 100000). 's' is a string that describes the value being - * converted. - * - * NOTE: this macro will raise a png_error if the range check fails, - * therefore it is normally only appropriate to use this on values - * that come from API calls or other sources where an out of range - * error indicates a programming error, not a data error! - * - * NOTE: by default this is off - the macro is not used - because the - * function call saves a lot of code. - */ -#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED -#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\ - ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0)) -#endif -/* else the corresponding function is defined below, inside the scope of the - * cplusplus test. - */ -#endif - -/* Constants for known chunk types. If you need to add a chunk, define the name - * here. For historical reasons these constants have the form png_<name>; i.e. - * the prefix is lower case. Please use decimal values as the parameters to - * match the ISO PNG specification and to avoid relying on the C locale - * interpretation of character values. - * - * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values - * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string - * to be generated if required. - * - * PNG_32b correctly produces a value shifted by up to 24 bits, even on - * architectures where (int) is only 16 bits. - */ -#define PNG_32b(b,s) ((png_uint_32)(b) << (s)) -#define PNG_U32(b1,b2,b3,b4) \ - (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0)) - -/* Constants for known chunk types. - * - * MAINTAINERS: If you need to add a chunk, define the name here. - * For historical reasons these constants have the form png_<name>; i.e. - * the prefix is lower case. Please use decimal values as the parameters to - * match the ISO PNG specification and to avoid relying on the C locale - * interpretation of character values. Please keep the list sorted. - * - * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk - * type. In fact the specification does not express chunk types this way, - * however using a 32-bit value means that the chunk type can be read from the - * stream using exactly the same code as used for a 32-bit unsigned value and - * can be examined far more efficiently (using one arithmetic compare). - * - * Prior to 1.5.6 the chunk type constants were expressed as C strings. The - * libpng API still uses strings for 'unknown' chunks and a macro, - * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice - * that for portable code numeric values must still be used; the string "IHDR" - * is not portable and neither is PNG_U32('I', 'H', 'D', 'R'). - * - * In 1.7.0 the definitions will be made public in png.h to avoid having to - * duplicate the same definitions in application code. - */ -#define png_IDAT PNG_U32( 73, 68, 65, 84) -#define png_IEND PNG_U32( 73, 69, 78, 68) -#define png_IHDR PNG_U32( 73, 72, 68, 82) -#define png_PLTE PNG_U32( 80, 76, 84, 69) -#define png_bKGD PNG_U32( 98, 75, 71, 68) -#define png_cHRM PNG_U32( 99, 72, 82, 77) -#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */ -#define png_gAMA PNG_U32(103, 65, 77, 65) -#define png_gIFg PNG_U32(103, 73, 70, 103) -#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */ -#define png_gIFx PNG_U32(103, 73, 70, 120) -#define png_hIST PNG_U32(104, 73, 83, 84) -#define png_iCCP PNG_U32(105, 67, 67, 80) -#define png_iTXt PNG_U32(105, 84, 88, 116) -#define png_oFFs PNG_U32(111, 70, 70, 115) -#define png_pCAL PNG_U32(112, 67, 65, 76) -#define png_pHYs PNG_U32(112, 72, 89, 115) -#define png_sBIT PNG_U32(115, 66, 73, 84) -#define png_sCAL PNG_U32(115, 67, 65, 76) -#define png_sPLT PNG_U32(115, 80, 76, 84) -#define png_sRGB PNG_U32(115, 82, 71, 66) -#define png_sTER PNG_U32(115, 84, 69, 82) -#define png_tEXt PNG_U32(116, 69, 88, 116) -#define png_tIME PNG_U32(116, 73, 77, 69) -#define png_tRNS PNG_U32(116, 82, 78, 83) -#define png_zTXt PNG_U32(122, 84, 88, 116) - -/* The following will work on (signed char*) strings, whereas the get_uint_32 - * macro will fail on top-bit-set values because of the sign extension. - */ -#define PNG_CHUNK_FROM_STRING(s)\ - PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3]) - -/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is - * signed and the argument is a (char[]) This macro will fail miserably on - * systems where (char) is more than 8 bits. - */ -#define PNG_STRING_FROM_CHUNK(s,c)\ - (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \ - ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\ - ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \ - ((char*)(s))[3]=(char)((c & 0xff))) - -/* Do the same but terminate with a null character. */ -#define PNG_CSTRING_FROM_CHUNK(s,c)\ - (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0) - -/* Test on flag values as defined in the spec (section 5.4): */ -#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29)) -#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c)) -#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21)) -#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13)) -#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5)) - -/* Gamma values (new at libpng-1.5.4): */ -#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */ -#define PNG_GAMMA_MAC_INVERSE 65909 -#define PNG_GAMMA_sRGB_INVERSE 45455 - -/* Almost everything below is C specific; the #defines above can be used in - * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot. - */ -#ifndef PNG_VERSION_INFO_ONLY - -#include "pngstruct.h" -#include "pnginfo.h" - -/* Validate the include paths - the include path used to generate pnglibconf.h - * must match that used in the build, or we must be using pnglibconf.h.prebuilt: - */ -#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM -# error ZLIB_VERNUM != PNG_ZLIB_VERNUM \ - "-I (include path) error: see the notes in pngpriv.h" - /* This means that when pnglibconf.h was built the copy of zlib.h that it - * used is not the same as the one being used here. Because the build of - * libpng makes decisions to use inflateInit2 and inflateReset2 based on the - * zlib version number and because this affects handling of certain broken - * PNG files the -I directives must match. - * - * The most likely explanation is that you passed a -I in CFLAGS. This will - * not work; all the preprocessor directories and in particular all the -I - * directives must be in CPPFLAGS. - */ -#endif - -/* This is used for 16-bit gamma tables -- only the top level pointers are - * const; this could be changed: - */ -typedef const png_uint_16p * png_const_uint_16pp; - -/* Added to libpng-1.5.7: sRGB conversion tables */ -#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ - defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) -#ifdef PNG_SIMPLIFIED_READ_SUPPORTED -PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]); - /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value, - * 0..65535. This table gives the closest 16-bit answers (no errors). - */ -#endif - -PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]); -PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]); - -#define PNG_sRGB_FROM_LINEAR(linear) \ - ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \ - + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))) - /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB - * encoded value with maximum error 0.646365. Note that the input is not a - * 16-bit value; it has been multiplied by 255! */ -#endif /* SIMPLIFIED_READ/WRITE */ - - -/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ -#ifdef __cplusplus -extern "C" { -#endif /* __cplusplus */ - -/* Internal functions; these are not exported from a DLL however because they - * are used within several of the C source files they have to be C extern. - * - * All of these functions must be declared with PNG_INTERNAL_FUNCTION. - */ - -/* Zlib support */ -#define PNG_UNEXPECTED_ZLIB_RETURN (-7) -PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret), - PNG_EMPTY); - /* Used by the zlib handling functions to ensure that z_stream::msg is always - * set before they return. - */ - -#ifdef PNG_WRITE_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr, - png_compression_bufferp *list),PNG_EMPTY); - /* Free the buffer list used by the compressed write code. */ -#endif - -#if defined(PNG_FLOATING_POINT_SUPPORTED) && \ - !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \ - (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \ - defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \ - defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \ - (defined(PNG_sCAL_SUPPORTED) && \ - defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)) -PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr, - double fp, png_const_charp text),PNG_EMPTY); -#endif - -/* Check the user version string for compatibility, returns false if the version - * numbers aren't compatible. - */ -PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr, - png_const_charp user_png_ver),PNG_EMPTY); - -/* Internal base allocator - no messages, NULL on failure to allocate. This - * does, however, call the application provided allocator and that could call - * png_error (although that would be a bug in the application implementation.) - */ -PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr, - png_alloc_size_t size),PNG_ALLOCATED); - -#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\ - defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) -/* Internal array allocator, outputs no error or warning messages on failure, - * just returns NULL. - */ -PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr, - int nelements, size_t element_size),PNG_ALLOCATED); - -/* The same but an existing array is extended by add_elements. This function - * also memsets the new elements to 0 and copies the old elements. The old - * array is not freed or altered. - */ -PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr, - png_const_voidp array, int old_elements, int add_elements, - size_t element_size),PNG_ALLOCATED); -#endif /* text, sPLT or unknown chunks */ - -/* Magic to create a struct when there is no struct to call the user supplied - * memory allocators. Because error handling has not been set up the memory - * handlers can't safely call png_error, but this is an obscure and undocumented - * restriction so libpng has to assume that the 'free' handler, at least, might - * call png_error. - */ -PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct, - (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn, - png_free_ptr free_fn),PNG_ALLOCATED); - -/* Free memory from internal libpng struct */ -PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr), - PNG_EMPTY); - -/* Free an allocated jmp_buf (always succeeds) */ -PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY); - -/* Function to allocate memory for zlib. PNGAPI is disallowed. */ -PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size), - PNG_ALLOCATED); - -/* Function to free memory for zlib. PNGAPI is disallowed. */ -PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY); - -/* Next four functions are used internally as callbacks. PNGCBAPI is required - * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to - * PNGCBAPI at 1.5.0 - */ - -PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr, - png_bytep data, png_size_t length),PNG_EMPTY); - -#ifdef PNG_PROGRESSIVE_READ_SUPPORTED -PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr, - png_bytep buffer, png_size_t length),PNG_EMPTY); -#endif - -PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr, - png_bytep data, png_size_t length),PNG_EMPTY); - -#ifdef PNG_WRITE_FLUSH_SUPPORTED -# ifdef PNG_STDIO_SUPPORTED -PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr), - PNG_EMPTY); -# endif -#endif - -/* Reset the CRC variable */ -PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY); - -/* Write the "data" buffer to whatever output you are using */ -PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr, - png_const_bytep data, png_size_t length),PNG_EMPTY); - -/* Read and check the PNG file signature */ -PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); - -/* Read the chunk header (length + type name) */ -PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr), - PNG_EMPTY); - -/* Read data from whatever input you are using into the "data" buffer */ -PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data, - png_size_t length),PNG_EMPTY); - -/* Read bytes into buf, and update png_ptr->crc */ -PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf, - png_uint_32 length),PNG_EMPTY); - -/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */ -PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr, - png_uint_32 skip),PNG_EMPTY); - -/* Read the CRC from the file and compare it to the libpng calculated CRC */ -PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY); - -/* Calculate the CRC over a section of data. Note that we are only - * passing a maximum of 64K on systems that have this as a memory limit, - * since this is the maximum buffer size we can specify. - */ -PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr, - png_const_bytep ptr, png_size_t length),PNG_EMPTY); - -#ifdef PNG_WRITE_FLUSH_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY); -#endif - -/* Write various chunks */ - -/* Write the IHDR chunk, and update the png_struct with the necessary - * information. - */ -PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr, - png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, - int compression_method, int filter_method, int interlace_method),PNG_EMPTY); - -PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr, - png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY); - -PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr, - png_const_bytep row_data, png_alloc_size_t row_data_length, int flush), - PNG_EMPTY); - -PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY); - -#ifdef PNG_WRITE_gAMA_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr, - png_fixed_point file_gamma),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_sBIT_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr, - png_const_color_8p sbit, int color_type),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_cHRM_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr, - const png_xy *xy), PNG_EMPTY); - /* The xy value must have been previously validated */ -#endif - -#ifdef PNG_WRITE_sRGB_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr, - int intent),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_iCCP_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr, - png_const_charp name, png_const_bytep profile), PNG_EMPTY); - /* The profile must have been previously validated for correctness, the - * length comes from the first four bytes. Only the base, deflate, - * compression is supported. - */ -#endif - -#ifdef PNG_WRITE_sPLT_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr, - png_const_sPLT_tp palette),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_tRNS_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr, - png_const_bytep trans, png_const_color_16p values, int number, - int color_type),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_bKGD_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr, - png_const_color_16p values, int color_type),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_hIST_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr, - png_const_uint_16p hist, int num_hist),PNG_EMPTY); -#endif - -/* Chunks that have keywords */ -#ifdef PNG_WRITE_tEXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr, - png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_zTXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp - key, png_const_charp text, int compression),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_iTXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr, - int compression, png_const_charp key, png_const_charp lang, - png_const_charp lang_key, png_const_charp text),PNG_EMPTY); -#endif - -#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */ -PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr, - png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_oFFs_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr, - png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_pCAL_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr, - png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, - png_const_charp units, png_charpp params),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_pHYs_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr, - png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, - int unit_type),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_tIME_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr, - png_const_timep mod_time),PNG_EMPTY); -#endif - -#ifdef PNG_WRITE_sCAL_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr, - int unit, png_const_charp width, png_const_charp height),PNG_EMPTY); -#endif - -/* Called when finished processing a row of data */ -PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr), - PNG_EMPTY); - -/* Internal use only. Called before first row of data */ -PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr), - PNG_EMPTY); - -/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an - * array of png_ptr->width pixels. If the image is not interlaced or this - * is the final pass this just does a memcpy, otherwise the "display" flag - * is used to determine whether to copy pixels that are not in the current pass. - * - * Because 'png_do_read_interlace' (below) replicates pixels this allows this - * function to achieve the documented 'blocky' appearance during interlaced read - * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row' - * are not changed if they are not in the current pass, when display is 0. - * - * 'display' must be 0 or 1, otherwise the memcpy will be done regardless. - * - * The API always reads from the png_struct row buffer and always assumes that - * it is full width (png_do_read_interlace has already been called.) - * - * This function is only ever used to write to row buffers provided by the - * caller of the relevant libpng API and the row must have already been - * transformed by the read transformations. - * - * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed - * bitmasks for use within the code, otherwise runtime generated masks are used. - * The default is compile time masks. - */ -#ifndef PNG_USE_COMPILE_TIME_MASKS -# define PNG_USE_COMPILE_TIME_MASKS 1 -#endif -PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr, - png_bytep row, int display),PNG_EMPTY); - -#ifdef PNG_READ_INTERLACING_SUPPORTED -/* Expand an interlaced row: the 'row_info' describes the pass data that has - * been read in and must correspond to the pixels in 'row', the pixels are - * expanded (moved apart) in 'row' to match the final layout, when doing this - * the pixels are *replicated* to the intervening space. This is essential for - * the correct operation of png_combine_row, above. - */ -PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info, - png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY); -#endif - -/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */ - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED -/* Grab pixels out of a row for an interlaced pass */ -PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info, - png_bytep row, int pass),PNG_EMPTY); -#endif - -/* Unfilter a row: check the filter value before calling this, there is no point - * calling it for PNG_FILTER_VALUE_NONE. - */ -PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop - row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY); - -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info, - png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); - -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop - row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); - -/* Choose the best filter to use and filter the row data */ -PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr, - png_row_infop row_info),PNG_EMPTY); - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr, - png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY); - /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer - * is NULL the function checks, instead, for the end of the stream. In this - * case a benign error will be issued if the stream end is not found or if - * extra data has to be consumed. - */ -PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr), - PNG_EMPTY); - /* This cleans up when the IDAT LZ stream does not end when the last image - * byte is read; there is still some pending input. - */ - -PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr), - PNG_EMPTY); - /* Finish a row while reading, dealing with interlacing passes, etc. */ -#endif /* SEQUENTIAL_READ */ - -/* Initialize the row buffers, etc. */ -PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY); - -#if PNG_ZLIB_VERNUM >= 0x1240 -PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush), - PNG_EMPTY); -# define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush) -#else /* Zlib < 1.2.4 */ -# define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush) -#endif /* Zlib < 1.2.4 */ - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -/* Optional call to update the users info structure */ -PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -#endif - -/* Shared transform functions, defined in pngtran.c */ -#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ - defined(PNG_READ_STRIP_ALPHA_SUPPORTED) -PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info, - png_bytep row, int at_start),PNG_EMPTY); -#endif - -#ifdef PNG_16BIT_SUPPORTED -#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) -PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info, - png_bytep row),PNG_EMPTY); -#endif -#endif - -#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ - defined(PNG_WRITE_PACKSWAP_SUPPORTED) -PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info, - png_bytep row),PNG_EMPTY); -#endif - -#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) -PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info, - png_bytep row),PNG_EMPTY); -#endif - -#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) -PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info, - png_bytep row),PNG_EMPTY); -#endif - -/* The following decodes the appropriate chunks, and does error correction, - * then calls the appropriate callback for the chunk if it is valid. - */ - -/* Decode the IHDR chunk */ -PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); - -#ifdef PNG_READ_bKGD_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_cHRM_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_gAMA_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_hIST_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_iCCP_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif /* READ_iCCP */ - -#ifdef PNG_READ_iTXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_oFFs_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_pCAL_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_pHYs_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_sBIT_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_sCAL_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_sPLT_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif /* READ_sPLT */ - -#ifdef PNG_READ_sRGB_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_tEXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_tIME_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_tRNS_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -#ifdef PNG_READ_zTXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -#endif - -PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr, - png_uint_32 chunk_name),PNG_EMPTY); - -PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY); - /* This is the function that gets called for unknown chunks. The 'keep' - * argument is either non-zero for a known chunk that has been set to be - * handled as unknown or zero for an unknown chunk. By default the function - * just skips the chunk or errors out if it is critical. - */ - -#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\ - defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) -PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling, - (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY); - /* Exactly as the API png_handle_as_unknown() except that the argument is a - * 32-bit chunk name, not a string. - */ -#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */ - -/* Handle the transformations for reading and writing */ -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr, - png_row_infop row_info),PNG_EMPTY); -#endif -#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr, - png_row_infop row_info),PNG_EMPTY); -#endif - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr), - PNG_EMPTY); -#endif - -#ifdef PNG_PROGRESSIVE_READ_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr), - PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr, - png_bytep buffer, png_size_t buffer_length),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr, - png_bytep buffer, png_size_t buffer_length),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr), - PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr, - png_bytep row),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr), - PNG_EMPTY); -# ifdef PNG_READ_tEXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -# endif -# ifdef PNG_READ_zTXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -# endif -# ifdef PNG_READ_iTXt_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr, - png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr, - png_inforp info_ptr),PNG_EMPTY); -# endif - -#endif /* PROGRESSIVE_READ */ - -/* Added at libpng version 1.6.0 */ -#ifdef PNG_GAMMA_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY); - /* Set the colorspace gamma with a value provided by the application or by - * the gAMA chunk on read. The value will override anything set by an ICC - * profile. - */ - -PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr, - png_inforp info_ptr), PNG_EMPTY); - /* Synchronize the info 'valid' flags with the colorspace */ - -PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr, - png_inforp info_ptr), PNG_EMPTY); - /* Copy the png_struct colorspace to the info_struct and call the above to - * synchronize the flags. Checks for NULL info_ptr and does nothing. - */ -#endif - -/* Added at libpng version 1.4.0 */ -#ifdef PNG_COLORSPACE_SUPPORTED -/* These internal functions are for maintaining the colorspace structure within - * a png_info or png_struct (or, indeed, both). - */ -PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities, - (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy, - int preferred), PNG_EMPTY); - -PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints, - (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ, - int preferred), PNG_EMPTY); - -#ifdef PNG_sRGB_SUPPORTED -PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr, - png_colorspacerp colorspace, int intent), PNG_EMPTY); - /* This does set the colorspace gAMA and cHRM values too, but doesn't set the - * flags to write them, if it returns false there was a problem and an error - * message has already been output (but the colorspace may still need to be - * synced to record the invalid flag). - */ -#endif /* sRGB */ - -#ifdef PNG_iCCP_SUPPORTED -PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_const_charp name, - png_uint_32 profile_length, png_const_bytep profile, int color_type), - PNG_EMPTY); - /* The 'name' is used for information only */ - -/* Routines for checking parts of an ICC profile. */ -PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_const_charp name, - png_uint_32 profile_length), PNG_EMPTY); -PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_const_charp name, - png_uint_32 profile_length, - png_const_bytep profile /* first 132 bytes only */, int color_type), - PNG_EMPTY); -PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr, - png_colorspacerp colorspace, png_const_charp name, - png_uint_32 profile_length, - png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY); -#ifdef PNG_sRGB_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,( - png_const_structrp png_ptr, png_colorspacerp colorspace, - png_const_bytep profile, uLong adler), PNG_EMPTY); - /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may - * be zero to indicate that it is not available. It is used, if provided, - * as a fast check on the profile when checking to see if it is sRGB. - */ -#endif -#endif /* iCCP */ - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients, - (png_structrp png_ptr), PNG_EMPTY); - /* Set the rgb_to_gray coefficients from the colorspace Y values */ -#endif /* READ_RGB_TO_GRAY */ -#endif /* COLORSPACE */ - -/* Added at libpng version 1.4.0 */ -PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr, - png_uint_32 width, png_uint_32 height, int bit_depth, - int color_type, int interlace_type, int compression_type, - int filter_type),PNG_EMPTY); - -/* Added at libpng version 1.5.10 */ -#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ - defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) -PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes, - (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY); -#endif - -#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) -PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr, - png_const_charp name),PNG_NORETURN); -#endif - -/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite - * the end. Always leaves the buffer nul terminated. Never errors out (and - * there is no error code.) - */ -PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize, - size_t pos, png_const_charp string),PNG_EMPTY); - -/* Various internal functions to handle formatted warning messages, currently - * only implemented for warnings. - */ -#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) -/* Utility to dump an unsigned value into a buffer, given a start pointer and - * and end pointer (which should point just *beyond* the end of the buffer!) - * Returns the pointer to the start of the formatted string. This utility only - * does unsigned values. - */ -PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start, - png_charp end, int format, png_alloc_size_t number),PNG_EMPTY); - -/* Convenience macro that takes an array: */ -#define PNG_FORMAT_NUMBER(buffer,format,number) \ - png_format_number(buffer, buffer + (sizeof buffer), format, number) - -/* Suggested size for a number buffer (enough for 64 bits and a sign!) */ -#define PNG_NUMBER_BUFFER_SIZE 24 - -/* These are the integer formats currently supported, the name is formed from - * the standard printf(3) format string. - */ -#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */ -#define PNG_NUMBER_FORMAT_02u 2 -#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */ -#define PNG_NUMBER_FORMAT_02d 2 -#define PNG_NUMBER_FORMAT_x 3 -#define PNG_NUMBER_FORMAT_02x 4 -#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */ -#endif - -#ifdef PNG_WARNINGS_SUPPORTED -/* New defines and members adding in libpng-1.5.4 */ -# define PNG_WARNING_PARAMETER_SIZE 32 -# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */ - -/* An l-value of this type has to be passed to the APIs below to cache the - * values of the parameters to a formatted warning message. - */ -typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][ - PNG_WARNING_PARAMETER_SIZE]; - -PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p, - int number, png_const_charp string),PNG_EMPTY); - /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters, - * including the trailing '\0'. - */ -PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned, - (png_warning_parameters p, int number, int format, png_alloc_size_t value), - PNG_EMPTY); - /* Use png_alloc_size_t because it is an unsigned type as big as any we - * need to output. Use the following for a signed value. - */ -PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed, - (png_warning_parameters p, int number, int format, png_int_32 value), - PNG_EMPTY); - -PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr, - png_warning_parameters p, png_const_charp message),PNG_EMPTY); - /* 'message' follows the X/Open approach of using @1, @2 to insert - * parameters previously supplied using the above functions. Errors in - * specifying the parameters will simply result in garbage substitutions. - */ -#endif - -#ifdef PNG_BENIGN_ERRORS_SUPPORTED -/* Application errors (new in 1.6); use these functions (declared below) for - * errors in the parameters or order of API function calls on read. The - * 'warning' should be used for an error that can be handled completely; the - * 'error' for one which can be handled safely but which may lose application - * information or settings. - * - * By default these both result in a png_error call prior to release, while in a - * released version the 'warning' is just a warning. However if the application - * explicitly disables benign errors (explicitly permitting the code to lose - * information) they both turn into warnings. - * - * If benign errors aren't supported they end up as the corresponding base call - * (png_warning or png_error.) - */ -PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr, - png_const_charp message),PNG_EMPTY); - /* The application provided invalid parameters to an API function or called - * an API function at the wrong time, libpng can completely recover. - */ - -PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr, - png_const_charp message),PNG_EMPTY); - /* As above but libpng will ignore the call, or attempt some other partial - * recovery from the error. - */ -#else -# define png_app_warning(pp,s) png_warning(pp,s) -# define png_app_error(pp,s) png_error(pp,s) -#endif - -PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr, - png_const_charp message, int error),PNG_EMPTY); - /* Report a recoverable issue in chunk data. On read this is used to report - * a problem found while reading a particular chunk and the - * png_chunk_benign_error or png_chunk_warning function is used as - * appropriate. On write this is used to report an error that comes from - * data set via an application call to a png_set_ API and png_app_error or - * png_app_warning is used as appropriate. - * - * The 'error' parameter must have one of the following values: - */ -#define PNG_CHUNK_WARNING 0 /* never an error */ -#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */ -#define PNG_CHUNK_ERROR 2 /* always an error */ - -/* ASCII to FP interfaces, currently only implemented if sCAL - * support is required. - */ -#if defined(PNG_sCAL_SUPPORTED) -/* MAX_DIGITS is actually the maximum number of characters in an sCAL - * width or height, derived from the precision (number of significant - * digits - a build time settable option) and assumptions about the - * maximum ridiculous exponent. - */ -#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/) - -#ifdef PNG_FLOATING_POINT_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr, - png_charp ascii, png_size_t size, double fp, unsigned int precision), - PNG_EMPTY); -#endif /* FLOATING_POINT */ - -#ifdef PNG_FIXED_POINT_SUPPORTED -PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr, - png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY); -#endif /* FIXED_POINT */ -#endif /* sCAL */ - -#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) -/* An internal API to validate the format of a floating point number. - * The result is the index of the next character. If the number is - * not valid it will be the index of a character in the supposed number. - * - * The format of a number is defined in the PNG extensions specification - * and this API is strictly conformant to that spec, not anyone elses! - * - * The format as a regular expression is: - * - * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)? - * - * or: - * - * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)? - * - * The complexity is that either integer or fraction must be present and the - * fraction is permitted to have no digits only if the integer is present. - * - * NOTE: The dangling E problem. - * There is a PNG valid floating point number in the following: - * - * PNG floating point numbers are not greedy. - * - * Working this out requires *TWO* character lookahead (because of the - * sign), the parser does not do this - it will fail at the 'r' - this - * doesn't matter for PNG sCAL chunk values, but it requires more care - * if the value were ever to be embedded in something more complex. Use - * ANSI-C strtod if you need the lookahead. - */ -/* State table for the parser. */ -#define PNG_FP_INTEGER 0 /* before or in integer */ -#define PNG_FP_FRACTION 1 /* before or in fraction */ -#define PNG_FP_EXPONENT 2 /* before or in exponent */ -#define PNG_FP_STATE 3 /* mask for the above */ -#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */ -#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */ -#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */ -#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */ -#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */ - -/* These three values don't affect the parser. They are set but not used. - */ -#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */ -#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */ -#define PNG_FP_NONZERO 256 /* A non-zero value */ -#define PNG_FP_STICKY 448 /* The above three flags */ - -/* This is available for the caller to store in 'state' if required. Do not - * call the parser after setting it (the parser sometimes clears it.) - */ -#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */ - -/* Result codes for the parser (boolean - true meants ok, false means - * not ok yet.) - */ -#define PNG_FP_MAYBE 0 /* The number may be valid in the future */ -#define PNG_FP_OK 1 /* The number is valid */ - -/* Tests on the sticky non-zero and negative flags. To pass these checks - * the state must also indicate that the whole number is valid - this is - * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this - * is equivalent to PNG_FP_OK above.) - */ -#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO) - /* NZ_MASK: the string is valid and a non-zero negative value */ -#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO) - /* Z MASK: the string is valid and a non-zero value. */ - /* PNG_FP_SAW_DIGIT: the string is valid. */ -#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT) -#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK) -#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK) - -/* The actual parser. This can be called repeatedly. It updates - * the index into the string and the state variable (which must - * be initialized to 0). It returns a result code, as above. There - * is no point calling the parser any more if it fails to advance to - * the end of the string - it is stuck on an invalid character (or - * terminated by '\0'). - * - * Note that the pointer will consume an E or even an E+ and then leave - * a 'maybe' state even though a preceding integer.fraction is valid. - * The PNG_FP_WAS_VALID flag indicates that a preceding substring was - * a valid number. It's possible to recover from this by calling - * the parser again (from the start, with state 0) but with a string - * that omits the last character (i.e. set the size to the index of - * the problem character.) This has not been tested within libpng. - */ -PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string, - png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY); - -/* This is the same but it checks a complete string and returns true - * only if it just contains a floating point number. As of 1.5.4 this - * function also returns the state at the end of parsing the number if - * it was valid (otherwise it returns 0.) This can be used for testing - * for negative or zero values using the sticky flag. - */ -PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string, - png_size_t size),PNG_EMPTY); -#endif /* pCAL || sCAL */ - -#if defined(PNG_GAMMA_SUPPORTED) ||\ - defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED) -/* Added at libpng version 1.5.0 */ -/* This is a utility to provide a*times/div (rounded) and indicate - * if there is an overflow. The result is a boolean - false (0) - * for overflow, true (1) if no overflow, in which case *res - * holds the result. - */ -PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a, - png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY); -#endif - -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) -/* Same deal, but issue a warning on overflow and return 0. */ -PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn, - (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by, - png_int_32 divided_by),PNG_EMPTY); -#endif - -#ifdef PNG_GAMMA_SUPPORTED -/* Calculate a reciprocal - used for gamma values. This returns - * 0 if the argument is 0 in order to maintain an undefined value; - * there are no warnings. - */ -PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a), - PNG_EMPTY); - -#ifdef PNG_READ_GAMMA_SUPPORTED -/* The same but gives a reciprocal of the product of two fixed point - * values. Accuracy is suitable for gamma calculations but this is - * not exact - use png_muldiv for that. Only required at present on read. - */ -PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a, - png_fixed_point b),PNG_EMPTY); -#endif - -/* Return true if the gamma value is significantly different from 1.0 */ -PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value), - PNG_EMPTY); -#endif - -#ifdef PNG_READ_GAMMA_SUPPORTED -/* Internal fixed point gamma correction. These APIs are called as - * required to convert single values - they don't need to be fast, - * they are not used when processing image pixel values. - * - * While the input is an 'unsigned' value it must actually be the - * correct bit value - 0..255 or 0..65535 as required. - */ -PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr, - unsigned int value, png_fixed_point gamma_value),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value, - png_fixed_point gamma_value),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value, - png_fixed_point gamma_value),PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr), - PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr, - int bit_depth),PNG_EMPTY); -#endif - -/* SIMPLIFIED READ/WRITE SUPPORT */ -#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ - defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) -/* The internal structure that png_image::opaque points to. */ -typedef struct png_control -{ - png_structp png_ptr; - png_infop info_ptr; - png_voidp error_buf; /* Always a jmp_buf at present. */ - - png_const_bytep memory; /* Memory buffer. */ - png_size_t size; /* Size of the memory buffer. */ - - unsigned int for_write :1; /* Otherwise it is a read structure */ - unsigned int owned_file :1; /* We own the file in io_ptr */ -} png_control; - -/* Return the pointer to the jmp_buf from a png_control: necessary because C - * does not reveal the type of the elements of jmp_buf. - */ -#ifdef __cplusplus -# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0]) -#else -# define png_control_jmp_buf(pc) ((pc)->error_buf) -#endif - -/* Utility to safely execute a piece of libpng code catching and logging any - * errors that might occur. Returns true on success, false on failure (either - * of the function or as a result of a png_error.) - */ -PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr, - png_const_charp error_message),PNG_NORETURN); - -#ifdef PNG_WARNINGS_SUPPORTED -PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr, - png_const_charp warning_message),PNG_EMPTY); -#else -# define png_safe_warning 0/*dummy argument*/ -#endif - -PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image, - int (*function)(png_voidp), png_voidp arg),PNG_EMPTY); - -/* Utility to log an error; this also cleans up the png_image; the function - * always returns 0 (false). - */ -PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image, - png_const_charp error_message),PNG_EMPTY); - -#ifndef PNG_SIMPLIFIED_READ_SUPPORTED -/* png_image_free is used by the write code but not exported */ -PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY); -#endif /* !SIMPLIFIED_READ */ - -#endif /* SIMPLIFIED READ/WRITE */ - -/* These are initialization functions for hardware specific PNG filter - * optimizations; list these here then select the appropriate one at compile - * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined - * the generic code is used. - */ -#ifdef PNG_FILTER_OPTIMIZATIONS -PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr, - unsigned int bpp), PNG_EMPTY); - /* Just declare the optimization that will be used */ -#else - /* List *all* the possible optimizations here - this branch is required if - * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in - * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing. - */ -PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon, - (png_structp png_ptr, unsigned int bpp), PNG_EMPTY); -PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2, - (png_structp png_ptr, unsigned int bpp), PNG_EMPTY); -#endif - -PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr, - png_const_charp key, png_bytep new_key), PNG_EMPTY); - -/* Maintainer: Put new private prototypes here ^ */ - -#include "pngdebug.h" - -#ifdef __cplusplus -} -#endif - -#endif /* PNG_VERSION_INFO_ONLY */ -#endif /* PNGPRIV_H */ diff --git a/third_party/libpng/pngread.c b/third_party/libpng/pngread.c deleted file mode 100644 index 64114ef117..0000000000 --- a/third_party/libpng/pngread.c +++ /dev/null @@ -1,4162 +0,0 @@ - -/* pngread.c - read a PNG file - * - * Last changed in libpng 1.6.17 [March 26, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This file contains routines that an application calls directly to - * read a PNG file or stream. - */ - -#include "pngpriv.h" -#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) -# include <errno.h> -#endif - -#ifdef PNG_READ_SUPPORTED - -/* Create a PNG structure for reading, and allocate any memory needed. */ -PNG_FUNCTION(png_structp,PNGAPI -png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr, - png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) -{ -#ifndef PNG_USER_MEM_SUPPORTED - png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr, - error_fn, warn_fn, NULL, NULL, NULL); -#else - return png_create_read_struct_2(user_png_ver, error_ptr, error_fn, - warn_fn, NULL, NULL, NULL); -} - -/* Alternate create PNG structure for reading, and allocate any memory - * needed. - */ -PNG_FUNCTION(png_structp,PNGAPI -png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, - png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, - png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) -{ - png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr, - error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); -#endif /* USER_MEM */ - - if (png_ptr != NULL) - { - png_ptr->mode = PNG_IS_READ_STRUCT; - - /* Added in libpng-1.6.0; this can be used to detect a read structure if - * required (it will be zero in a write structure.) - */ -# ifdef PNG_SEQUENTIAL_READ_SUPPORTED - png_ptr->IDAT_read_size = PNG_IDAT_READ_SIZE; -# endif - -# ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED - png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; - - /* In stable builds only warn if an application error can be completely - * handled. - */ -# if PNG_RELEASE_BUILD - png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; -# endif -# endif - - /* TODO: delay this, it can be done in png_init_io (if the app doesn't - * do it itself) avoiding setting the default function if it is not - * required. - */ - png_set_read_fn(png_ptr, NULL, NULL); - } - - return png_ptr; -} - - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read the information before the actual image data. This has been - * changed in v0.90 to allow reading a file that already has the magic - * bytes read from the stream. You can tell libpng how many bytes have - * been read from the beginning of the stream (up to the maximum of 8) - * via png_set_sig_bytes(), and we will only check the remaining bytes - * here. The application can then have access to the signature bytes we - * read if it is determined that this isn't a valid PNG file. - */ -void PNGAPI -png_read_info(png_structrp png_ptr, png_inforp info_ptr) -{ -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - int keep; -#endif - - png_debug(1, "in png_read_info"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - /* Read and check the PNG file signature. */ - png_read_sig(png_ptr, info_ptr); - - for (;;) - { - png_uint_32 length = png_read_chunk_header(png_ptr); - png_uint_32 chunk_name = png_ptr->chunk_name; - - /* IDAT logic needs to happen here to simplify getting the two flags - * right. - */ - if (chunk_name == png_IDAT) - { - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "Missing IHDR before IDAT"); - - else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && - (png_ptr->mode & PNG_HAVE_PLTE) == 0) - png_chunk_error(png_ptr, "Missing PLTE before IDAT"); - - else if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) - png_chunk_benign_error(png_ptr, "Too many IDATs found"); - - png_ptr->mode |= PNG_HAVE_IDAT; - } - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - png_ptr->mode |= PNG_AFTER_IDAT; - - /* This should be a binary subdivision search or a hash for - * matching the chunk name rather than a linear search. - */ - if (chunk_name == png_IHDR) - png_handle_IHDR(png_ptr, info_ptr, length); - - else if (chunk_name == png_IEND) - png_handle_IEND(png_ptr, info_ptr, length); - -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) - { - png_handle_unknown(png_ptr, info_ptr, length, keep); - - if (chunk_name == png_PLTE) - png_ptr->mode |= PNG_HAVE_PLTE; - - else if (chunk_name == png_IDAT) - { - png_ptr->idat_size = 0; /* It has been consumed */ - break; - } - } -#endif - else if (chunk_name == png_PLTE) - png_handle_PLTE(png_ptr, info_ptr, length); - - else if (chunk_name == png_IDAT) - { - png_ptr->idat_size = length; - break; - } - -#ifdef PNG_READ_bKGD_SUPPORTED - else if (chunk_name == png_bKGD) - png_handle_bKGD(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_cHRM_SUPPORTED - else if (chunk_name == png_cHRM) - png_handle_cHRM(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_gAMA_SUPPORTED - else if (chunk_name == png_gAMA) - png_handle_gAMA(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_hIST_SUPPORTED - else if (chunk_name == png_hIST) - png_handle_hIST(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_oFFs_SUPPORTED - else if (chunk_name == png_oFFs) - png_handle_oFFs(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_pCAL_SUPPORTED - else if (chunk_name == png_pCAL) - png_handle_pCAL(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_sCAL_SUPPORTED - else if (chunk_name == png_sCAL) - png_handle_sCAL(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_pHYs_SUPPORTED - else if (chunk_name == png_pHYs) - png_handle_pHYs(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_sBIT_SUPPORTED - else if (chunk_name == png_sBIT) - png_handle_sBIT(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_sRGB_SUPPORTED - else if (chunk_name == png_sRGB) - png_handle_sRGB(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_iCCP_SUPPORTED - else if (chunk_name == png_iCCP) - png_handle_iCCP(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_sPLT_SUPPORTED - else if (chunk_name == png_sPLT) - png_handle_sPLT(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_tEXt_SUPPORTED - else if (chunk_name == png_tEXt) - png_handle_tEXt(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_tIME_SUPPORTED - else if (chunk_name == png_tIME) - png_handle_tIME(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_tRNS_SUPPORTED - else if (chunk_name == png_tRNS) - png_handle_tRNS(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_zTXt_SUPPORTED - else if (chunk_name == png_zTXt) - png_handle_zTXt(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_iTXt_SUPPORTED - else if (chunk_name == png_iTXt) - png_handle_iTXt(png_ptr, info_ptr, length); -#endif - - else - png_handle_unknown(png_ptr, info_ptr, length, - PNG_HANDLE_CHUNK_AS_DEFAULT); - } -} -#endif /* SEQUENTIAL_READ */ - -/* Optional call to update the users info_ptr structure */ -void PNGAPI -png_read_update_info(png_structrp png_ptr, png_inforp info_ptr) -{ - png_debug(1, "in png_read_update_info"); - - if (png_ptr != NULL) - { - if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) - { - png_read_start_row(png_ptr); - -# ifdef PNG_READ_TRANSFORMS_SUPPORTED - png_read_transform_info(png_ptr, info_ptr); -# else - PNG_UNUSED(info_ptr) -# endif - } - - /* New in 1.6.0 this avoids the bug of doing the initializations twice */ - else - png_app_error(png_ptr, - "png_read_update_info/png_start_read_image: duplicate call"); - } -} - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Initialize palette, background, etc, after transformations - * are set, but before any reading takes place. This allows - * the user to obtain a gamma-corrected palette, for example. - * If the user doesn't call this, we will do it ourselves. - */ -void PNGAPI -png_start_read_image(png_structrp png_ptr) -{ - png_debug(1, "in png_start_read_image"); - - if (png_ptr != NULL) - { - if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) - png_read_start_row(png_ptr); - - /* New in 1.6.0 this avoids the bug of doing the initializations twice */ - else - png_app_error(png_ptr, - "png_start_read_image/png_read_update_info: duplicate call"); - } -} -#endif /* SEQUENTIAL_READ */ - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -#ifdef PNG_MNG_FEATURES_SUPPORTED -/* Undoes intrapixel differencing, - * NOTE: this is apparently only supported in the 'sequential' reader. - */ -static void -png_do_read_intrapixel(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_read_intrapixel"); - - if ( - (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) - { - int bytes_per_pixel; - png_uint_32 row_width = row_info->width; - - if (row_info->bit_depth == 8) - { - png_bytep rp; - png_uint_32 i; - - if (row_info->color_type == PNG_COLOR_TYPE_RGB) - bytes_per_pixel = 3; - - else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - bytes_per_pixel = 4; - - else - return; - - for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) - { - *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff); - *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff); - } - } - else if (row_info->bit_depth == 16) - { - png_bytep rp; - png_uint_32 i; - - if (row_info->color_type == PNG_COLOR_TYPE_RGB) - bytes_per_pixel = 6; - - else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - bytes_per_pixel = 8; - - else - return; - - for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) - { - png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); - png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); - png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); - png_uint_32 red = (s0 + s1 + 65536) & 0xffff; - png_uint_32 blue = (s2 + s1 + 65536) & 0xffff; - *(rp ) = (png_byte)((red >> 8) & 0xff); - *(rp + 1) = (png_byte)(red & 0xff); - *(rp + 4) = (png_byte)((blue >> 8) & 0xff); - *(rp + 5) = (png_byte)(blue & 0xff); - } - } - } -} -#endif /* MNG_FEATURES */ - -void PNGAPI -png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row) -{ - png_row_info row_info; - - if (png_ptr == NULL) - return; - - png_debug2(1, "in png_read_row (row %lu, pass %d)", - (unsigned long)png_ptr->row_number, png_ptr->pass); - - /* png_read_start_row sets the information (in particular iwidth) for this - * interlace pass. - */ - if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) - png_read_start_row(png_ptr); - - /* 1.5.6: row_info moved out of png_struct to a local here. */ - row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ - row_info.color_type = png_ptr->color_type; - row_info.bit_depth = png_ptr->bit_depth; - row_info.channels = png_ptr->channels; - row_info.pixel_depth = png_ptr->pixel_depth; - row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); - -#ifdef PNG_WARNINGS_SUPPORTED - if (png_ptr->row_number == 0 && png_ptr->pass == 0) - { - /* Check for transforms that have been set but were defined out */ -#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED) - if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) - png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined"); -#endif - -#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED) - if ((png_ptr->transformations & PNG_FILLER) != 0) - png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined"); -#endif - -#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ - !defined(PNG_READ_PACKSWAP_SUPPORTED) - if ((png_ptr->transformations & PNG_PACKSWAP) != 0) - png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined"); -#endif - -#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED) - if ((png_ptr->transformations & PNG_PACK) != 0) - png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined"); -#endif - -#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) - if ((png_ptr->transformations & PNG_SHIFT) != 0) - png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined"); -#endif - -#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED) - if ((png_ptr->transformations & PNG_BGR) != 0) - png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined"); -#endif - -#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED) - if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) - png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined"); -#endif - } -#endif /* WARNINGS */ - -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* If interlaced and we do not need a new row, combine row and return. - * Notice that the pixels we have from previous rows have been transformed - * already; we can only combine like with like (transformed or - * untransformed) and, because of the libpng API for interlaced images, this - * means we must transform before de-interlacing. - */ - if (png_ptr->interlaced != 0 && - (png_ptr->transformations & PNG_INTERLACE) != 0) - { - switch (png_ptr->pass) - { - case 0: - if (png_ptr->row_number & 0x07) - { - if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, 1/*display*/); - png_read_finish_row(png_ptr); - return; - } - break; - - case 1: - if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) - { - if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, 1/*display*/); - - png_read_finish_row(png_ptr); - return; - } - break; - - case 2: - if ((png_ptr->row_number & 0x07) != 4) - { - if (dsp_row != NULL && (png_ptr->row_number & 4)) - png_combine_row(png_ptr, dsp_row, 1/*display*/); - - png_read_finish_row(png_ptr); - return; - } - break; - - case 3: - if ((png_ptr->row_number & 3) || png_ptr->width < 3) - { - if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, 1/*display*/); - - png_read_finish_row(png_ptr); - return; - } - break; - - case 4: - if ((png_ptr->row_number & 3) != 2) - { - if (dsp_row != NULL && (png_ptr->row_number & 2)) - png_combine_row(png_ptr, dsp_row, 1/*display*/); - - png_read_finish_row(png_ptr); - return; - } - break; - - case 5: - if ((png_ptr->row_number & 1) || png_ptr->width < 2) - { - if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, 1/*display*/); - - png_read_finish_row(png_ptr); - return; - } - break; - - default: - case 6: - if ((png_ptr->row_number & 1) == 0) - { - png_read_finish_row(png_ptr); - return; - } - break; - } - } -#endif - - if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) - png_error(png_ptr, "Invalid attempt to read row data"); - - /* Fill the row with IDAT data: */ - png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1); - - if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) - { - if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) - png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, - png_ptr->prev_row + 1, png_ptr->row_buf[0]); - else - png_error(png_ptr, "bad adaptive filter value"); - } - - /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before - * 1.5.6, while the buffer really is this big in current versions of libpng - * it may not be in the future, so this was changed just to copy the - * interlaced count: - */ - memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); - -#ifdef PNG_MNG_FEATURES_SUPPORTED - if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && - (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) - { - /* Intrapixel differencing */ - png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1); - } -#endif - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - if (png_ptr->transformations) - png_do_read_transformations(png_ptr, &row_info); -#endif - - /* The transformed pixel depth should match the depth now in row_info. */ - if (png_ptr->transformed_pixel_depth == 0) - { - png_ptr->transformed_pixel_depth = row_info.pixel_depth; - if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) - png_error(png_ptr, "sequential row overflow"); - } - - else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) - png_error(png_ptr, "internal sequential row size calculation error"); - -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Expand interlaced rows to full size */ - if (png_ptr->interlaced != 0 && - (png_ptr->transformations & PNG_INTERLACE) != 0) - { - if (png_ptr->pass < 6) - png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, - png_ptr->transformations); - - if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, 1/*display*/); - - if (row != NULL) - png_combine_row(png_ptr, row, 0/*row*/); - } - - else -#endif - { - if (row != NULL) - png_combine_row(png_ptr, row, -1/*ignored*/); - - if (dsp_row != NULL) - png_combine_row(png_ptr, dsp_row, -1/*ignored*/); - } - png_read_finish_row(png_ptr); - - if (png_ptr->read_row_fn != NULL) - (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); - -} -#endif /* SEQUENTIAL_READ */ - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read one or more rows of image data. If the image is interlaced, - * and png_set_interlace_handling() has been called, the rows need to - * contain the contents of the rows from the previous pass. If the - * image has alpha or transparency, and png_handle_alpha()[*] has been - * called, the rows contents must be initialized to the contents of the - * screen. - * - * "row" holds the actual image, and pixels are placed in it - * as they arrive. If the image is displayed after each pass, it will - * appear to "sparkle" in. "display_row" can be used to display a - * "chunky" progressive image, with finer detail added as it becomes - * available. If you do not want this "chunky" display, you may pass - * NULL for display_row. If you do not want the sparkle display, and - * you have not called png_handle_alpha(), you may pass NULL for rows. - * If you have called png_handle_alpha(), and the image has either an - * alpha channel or a transparency chunk, you must provide a buffer for - * rows. In this case, you do not have to provide a display_row buffer - * also, but you may. If the image is not interlaced, or if you have - * not called png_set_interlace_handling(), the display_row buffer will - * be ignored, so pass NULL to it. - * - * [*] png_handle_alpha() does not exist yet, as of this version of libpng - */ - -void PNGAPI -png_read_rows(png_structrp png_ptr, png_bytepp row, - png_bytepp display_row, png_uint_32 num_rows) -{ - png_uint_32 i; - png_bytepp rp; - png_bytepp dp; - - png_debug(1, "in png_read_rows"); - - if (png_ptr == NULL) - return; - - rp = row; - dp = display_row; - if (rp != NULL && dp != NULL) - for (i = 0; i < num_rows; i++) - { - png_bytep rptr = *rp++; - png_bytep dptr = *dp++; - - png_read_row(png_ptr, rptr, dptr); - } - - else if (rp != NULL) - for (i = 0; i < num_rows; i++) - { - png_bytep rptr = *rp; - png_read_row(png_ptr, rptr, NULL); - rp++; - } - - else if (dp != NULL) - for (i = 0; i < num_rows; i++) - { - png_bytep dptr = *dp; - png_read_row(png_ptr, NULL, dptr); - dp++; - } -} -#endif /* SEQUENTIAL_READ */ - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read the entire image. If the image has an alpha channel or a tRNS - * chunk, and you have called png_handle_alpha()[*], you will need to - * initialize the image to the current image that PNG will be overlaying. - * We set the num_rows again here, in case it was incorrectly set in - * png_read_start_row() by a call to png_read_update_info() or - * png_start_read_image() if png_set_interlace_handling() wasn't called - * prior to either of these functions like it should have been. You can - * only call this function once. If you desire to have an image for - * each pass of a interlaced image, use png_read_rows() instead. - * - * [*] png_handle_alpha() does not exist yet, as of this version of libpng - */ -void PNGAPI -png_read_image(png_structrp png_ptr, png_bytepp image) -{ - png_uint_32 i, image_height; - int pass, j; - png_bytepp rp; - - png_debug(1, "in png_read_image"); - - if (png_ptr == NULL) - return; - -#ifdef PNG_READ_INTERLACING_SUPPORTED - if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) - { - pass = png_set_interlace_handling(png_ptr); - /* And make sure transforms are initialized. */ - png_start_read_image(png_ptr); - } - else - { - if (png_ptr->interlaced != 0 && - (png_ptr->transformations & PNG_INTERLACE) == 0) - { - /* Caller called png_start_read_image or png_read_update_info without - * first turning on the PNG_INTERLACE transform. We can fix this here, - * but the caller should do it! - */ - png_warning(png_ptr, "Interlace handling should be turned on when " - "using png_read_image"); - /* Make sure this is set correctly */ - png_ptr->num_rows = png_ptr->height; - } - - /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in - * the above error case. - */ - pass = png_set_interlace_handling(png_ptr); - } -#else - if (png_ptr->interlaced) - png_error(png_ptr, - "Cannot read interlaced image -- interlace handler disabled"); - - pass = 1; -#endif - - image_height=png_ptr->height; - - for (j = 0; j < pass; j++) - { - rp = image; - for (i = 0; i < image_height; i++) - { - png_read_row(png_ptr, *rp, NULL); - rp++; - } - } -} -#endif /* SEQUENTIAL_READ */ - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -/* Read the end of the PNG file. Will not read past the end of the - * file, will verify the end is accurate, and will read any comments - * or time information at the end of the file, if info is not NULL. - */ -void PNGAPI -png_read_end(png_structrp png_ptr, png_inforp info_ptr) -{ -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - int keep; -#endif - - png_debug(1, "in png_read_end"); - - if (png_ptr == NULL) - return; - - /* If png_read_end is called in the middle of reading the rows there may - * still be pending IDAT data and an owned zstream. Deal with this here. - */ -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0) -#endif - png_read_finish_IDAT(png_ptr); - -#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED - /* Report invalid palette index; added at libng-1.5.10 */ - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && - png_ptr->num_palette_max > png_ptr->num_palette) - png_benign_error(png_ptr, "Read palette index exceeding num_palette"); -#endif - - do - { - png_uint_32 length = png_read_chunk_header(png_ptr); - png_uint_32 chunk_name = png_ptr->chunk_name; - - if (chunk_name == png_IEND) - png_handle_IEND(png_ptr, info_ptr, length); - - else if (chunk_name == png_IHDR) - png_handle_IHDR(png_ptr, info_ptr, length); - - else if (info_ptr == NULL) - png_crc_finish(png_ptr, length); - -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) - { - if (chunk_name == png_IDAT) - { - if ((length > 0) || - (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) - png_benign_error(png_ptr, "Too many IDATs found"); - } - png_handle_unknown(png_ptr, info_ptr, length, keep); - if (chunk_name == png_PLTE) - png_ptr->mode |= PNG_HAVE_PLTE; - } -#endif - - else if (chunk_name == png_IDAT) - { - /* Zero length IDATs are legal after the last IDAT has been - * read, but not after other chunks have been read. - */ - if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) - png_benign_error(png_ptr, "Too many IDATs found"); - - png_crc_finish(png_ptr, length); - } - else if (chunk_name == png_PLTE) - png_handle_PLTE(png_ptr, info_ptr, length); - -#ifdef PNG_READ_bKGD_SUPPORTED - else if (chunk_name == png_bKGD) - png_handle_bKGD(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_cHRM_SUPPORTED - else if (chunk_name == png_cHRM) - png_handle_cHRM(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_gAMA_SUPPORTED - else if (chunk_name == png_gAMA) - png_handle_gAMA(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_hIST_SUPPORTED - else if (chunk_name == png_hIST) - png_handle_hIST(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_oFFs_SUPPORTED - else if (chunk_name == png_oFFs) - png_handle_oFFs(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_pCAL_SUPPORTED - else if (chunk_name == png_pCAL) - png_handle_pCAL(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_sCAL_SUPPORTED - else if (chunk_name == png_sCAL) - png_handle_sCAL(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_pHYs_SUPPORTED - else if (chunk_name == png_pHYs) - png_handle_pHYs(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_sBIT_SUPPORTED - else if (chunk_name == png_sBIT) - png_handle_sBIT(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_sRGB_SUPPORTED - else if (chunk_name == png_sRGB) - png_handle_sRGB(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_iCCP_SUPPORTED - else if (chunk_name == png_iCCP) - png_handle_iCCP(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_sPLT_SUPPORTED - else if (chunk_name == png_sPLT) - png_handle_sPLT(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_tEXt_SUPPORTED - else if (chunk_name == png_tEXt) - png_handle_tEXt(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_tIME_SUPPORTED - else if (chunk_name == png_tIME) - png_handle_tIME(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_tRNS_SUPPORTED - else if (chunk_name == png_tRNS) - png_handle_tRNS(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_zTXt_SUPPORTED - else if (chunk_name == png_zTXt) - png_handle_zTXt(png_ptr, info_ptr, length); -#endif - -#ifdef PNG_READ_iTXt_SUPPORTED - else if (chunk_name == png_iTXt) - png_handle_iTXt(png_ptr, info_ptr, length); -#endif - - else - png_handle_unknown(png_ptr, info_ptr, length, - PNG_HANDLE_CHUNK_AS_DEFAULT); - } while ((png_ptr->mode & PNG_HAVE_IEND) == 0); -} -#endif /* SEQUENTIAL_READ */ - -/* Free all memory used in the read struct */ -static void -png_read_destroy(png_structrp png_ptr) -{ - png_debug(1, "in png_read_destroy"); - -#ifdef PNG_READ_GAMMA_SUPPORTED - png_destroy_gamma_table(png_ptr); -#endif - - png_free(png_ptr, png_ptr->big_row_buf); - png_ptr->big_row_buf = NULL; - png_free(png_ptr, png_ptr->big_prev_row); - png_ptr->big_prev_row = NULL; - png_free(png_ptr, png_ptr->read_buffer); - png_ptr->read_buffer = NULL; - -#ifdef PNG_READ_QUANTIZE_SUPPORTED - png_free(png_ptr, png_ptr->palette_lookup); - png_ptr->palette_lookup = NULL; - png_free(png_ptr, png_ptr->quantize_index); - png_ptr->quantize_index = NULL; -#endif - - if ((png_ptr->free_me & PNG_FREE_PLTE) != 0) - { - png_zfree(png_ptr, png_ptr->palette); - png_ptr->palette = NULL; - } - png_ptr->free_me &= ~PNG_FREE_PLTE; - -#if defined(PNG_tRNS_SUPPORTED) || \ - defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if ((png_ptr->free_me & PNG_FREE_TRNS) != 0) - { - png_free(png_ptr, png_ptr->trans_alpha); - png_ptr->trans_alpha = NULL; - } - png_ptr->free_me &= ~PNG_FREE_TRNS; -#endif - - inflateEnd(&png_ptr->zstream); - -#ifdef PNG_PROGRESSIVE_READ_SUPPORTED - png_free(png_ptr, png_ptr->save_buffer); - png_ptr->save_buffer = NULL; -#endif - -#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \ - defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) - png_free(png_ptr, png_ptr->unknown_chunk.data); - png_ptr->unknown_chunk.data = NULL; -#endif - -#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED - png_free(png_ptr, png_ptr->chunk_list); - png_ptr->chunk_list = NULL; -#endif - - /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error - * callbacks are still set at this point. They are required to complete the - * destruction of the png_struct itself. - */ -} - -/* Free all memory used by the read */ -void PNGAPI -png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, - png_infopp end_info_ptr_ptr) -{ - png_structrp png_ptr = NULL; - - png_debug(1, "in png_destroy_read_struct"); - - if (png_ptr_ptr != NULL) - png_ptr = *png_ptr_ptr; - - if (png_ptr == NULL) - return; - - /* libpng 1.6.0: use the API to destroy info structs to ensure consistent - * behavior. Prior to 1.6.0 libpng did extra 'info' destruction in this API. - * The extra was, apparently, unnecessary yet this hides memory leak bugs. - */ - png_destroy_info_struct(png_ptr, end_info_ptr_ptr); - png_destroy_info_struct(png_ptr, info_ptr_ptr); - - *png_ptr_ptr = NULL; - png_read_destroy(png_ptr); - png_destroy_png_struct(png_ptr); -} - -void PNGAPI -png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn) -{ - if (png_ptr == NULL) - return; - - png_ptr->read_row_fn = read_row_fn; -} - - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -#ifdef PNG_INFO_IMAGE_SUPPORTED -void PNGAPI -png_read_png(png_structrp png_ptr, png_inforp info_ptr, - int transforms, - voidp params) -{ - if (png_ptr == NULL || info_ptr == NULL) - return; - - /* png_read_info() gives us all of the information from the - * PNG file before the first IDAT (image data chunk). - */ - png_read_info(png_ptr, info_ptr); - if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep))) - png_error(png_ptr, "Image is too high to process with png_read_png()"); - - /* -------------- image transformations start here ------------------- */ - /* libpng 1.6.10: add code to cause a png_app_error if a selected TRANSFORM - * is not implemented. This will only happen in de-configured (non-default) - * libpng builds. The results can be unexpected - png_read_png may return - * short or mal-formed rows because the transform is skipped. - */ - - /* Tell libpng to strip 16-bit/color files down to 8 bits per color. - */ - if ((transforms & PNG_TRANSFORM_SCALE_16) != 0) - /* Added at libpng-1.5.4. "strip_16" produces the same result that it - * did in earlier versions, while "scale_16" is now more accurate. - */ -#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED - png_set_scale_16(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_SCALE_16 not supported"); -#endif - - /* If both SCALE and STRIP are required pngrtran will effectively cancel the - * latter by doing SCALE first. This is ok and allows apps not to check for - * which is supported to get the right answer. - */ - if ((transforms & PNG_TRANSFORM_STRIP_16) != 0) -#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED - png_set_strip_16(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_16 not supported"); -#endif - - /* Strip alpha bytes from the input data without combining with - * the background (not recommended). - */ - if ((transforms & PNG_TRANSFORM_STRIP_ALPHA) != 0) -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - png_set_strip_alpha(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_ALPHA not supported"); -#endif - - /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single - * byte into separate bytes (useful for paletted and grayscale images). - */ - if ((transforms & PNG_TRANSFORM_PACKING) != 0) -#ifdef PNG_READ_PACK_SUPPORTED - png_set_packing(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); -#endif - - /* Change the order of packed pixels to least significant bit first - * (not useful if you are using png_set_packing). - */ - if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) -#ifdef PNG_READ_PACKSWAP_SUPPORTED - png_set_packswap(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); -#endif - - /* Expand paletted colors into true RGB triplets - * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel - * Expand paletted or RGB images with transparency to full alpha - * channels so the data will be available as RGBA quartets. - */ - if ((transforms & PNG_TRANSFORM_EXPAND) != 0) -#ifdef PNG_READ_EXPAND_SUPPORTED - png_set_expand(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND not supported"); -#endif - - /* We don't handle background color or gamma transformation or quantizing. - */ - - /* Invert monochrome files to have 0 as white and 1 as black - */ - if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) -#ifdef PNG_READ_INVERT_SUPPORTED - png_set_invert_mono(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); -#endif - - /* If you want to shift the pixel values from the range [0,255] or - * [0,65535] to the original [0,7] or [0,31], or whatever range the - * colors were originally in: - */ - if ((transforms & PNG_TRANSFORM_SHIFT) != 0) -#ifdef PNG_READ_SHIFT_SUPPORTED - if ((info_ptr->valid & PNG_INFO_sBIT) != 0) - png_set_shift(png_ptr, &info_ptr->sig_bit); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); -#endif - - /* Flip the RGB pixels to BGR (or RGBA to BGRA) */ - if ((transforms & PNG_TRANSFORM_BGR) != 0) -#ifdef PNG_READ_BGR_SUPPORTED - png_set_bgr(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); -#endif - - /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */ - if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) -#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED - png_set_swap_alpha(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); -#endif - - /* Swap bytes of 16-bit files to least significant byte first */ - if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) -#ifdef PNG_READ_SWAP_SUPPORTED - png_set_swap(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); -#endif - -/* Added at libpng-1.2.41 */ - /* Invert the alpha channel from opacity to transparency */ - if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) -#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED - png_set_invert_alpha(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); -#endif - -/* Added at libpng-1.2.41 */ - /* Expand grayscale image to RGB */ - if ((transforms & PNG_TRANSFORM_GRAY_TO_RGB) != 0) -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED - png_set_gray_to_rgb(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_GRAY_TO_RGB not supported"); -#endif - -/* Added at libpng-1.5.4 */ - if ((transforms & PNG_TRANSFORM_EXPAND_16) != 0) -#ifdef PNG_READ_EXPAND_16_SUPPORTED - png_set_expand_16(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND_16 not supported"); -#endif - - /* We don't handle adding filler bytes */ - - /* We use png_read_image and rely on that for interlace handling, but we also - * call png_read_update_info therefore must turn on interlace handling now: - */ - (void)png_set_interlace_handling(png_ptr); - - /* Optional call to gamma correct and add the background to the palette - * and update info structure. REQUIRED if you are expecting libpng to - * update the palette for you (i.e., you selected such a transform above). - */ - png_read_update_info(png_ptr, info_ptr); - - /* -------------- image transformations end here ------------------- */ - - png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); - if (info_ptr->row_pointers == NULL) - { - png_uint_32 iptr; - - info_ptr->row_pointers = png_voidcast(png_bytepp, png_malloc(png_ptr, - info_ptr->height * (sizeof (png_bytep)))); - - for (iptr=0; iptr<info_ptr->height; iptr++) - info_ptr->row_pointers[iptr] = NULL; - - info_ptr->free_me |= PNG_FREE_ROWS; - - for (iptr = 0; iptr < info_ptr->height; iptr++) - info_ptr->row_pointers[iptr] = png_voidcast(png_bytep, - png_malloc(png_ptr, info_ptr->rowbytes)); - } - - png_read_image(png_ptr, info_ptr->row_pointers); - info_ptr->valid |= PNG_INFO_IDAT; - - /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ - png_read_end(png_ptr, info_ptr); - - PNG_UNUSED(params) -} -#endif /* INFO_IMAGE */ -#endif /* SEQUENTIAL_READ */ - -#ifdef PNG_SIMPLIFIED_READ_SUPPORTED -/* SIMPLIFIED READ - * - * This code currently relies on the sequential reader, though it could easily - * be made to work with the progressive one. - */ -/* Arguments to png_image_finish_read: */ - -/* Encoding of PNG data (used by the color-map code) */ -# define P_NOTSET 0 /* File encoding not yet known */ -# define P_sRGB 1 /* 8-bit encoded to sRGB gamma */ -# define P_LINEAR 2 /* 16-bit linear: not encoded, NOT pre-multiplied! */ -# define P_FILE 3 /* 8-bit encoded to file gamma, not sRGB or linear */ -# define P_LINEAR8 4 /* 8-bit linear: only from a file value */ - -/* Color-map processing: after libpng has run on the PNG image further - * processing may be needed to convert the data to color-map indices. - */ -#define PNG_CMAP_NONE 0 -#define PNG_CMAP_GA 1 /* Process GA data to a color-map with alpha */ -#define PNG_CMAP_TRANS 2 /* Process GA data to a background index */ -#define PNG_CMAP_RGB 3 /* Process RGB data */ -#define PNG_CMAP_RGB_ALPHA 4 /* Process RGBA data */ - -/* The following document where the background is for each processing case. */ -#define PNG_CMAP_NONE_BACKGROUND 256 -#define PNG_CMAP_GA_BACKGROUND 231 -#define PNG_CMAP_TRANS_BACKGROUND 254 -#define PNG_CMAP_RGB_BACKGROUND 256 -#define PNG_CMAP_RGB_ALPHA_BACKGROUND 216 - -typedef struct -{ - /* Arguments: */ - png_imagep image; - png_voidp buffer; - png_int_32 row_stride; - png_voidp colormap; - png_const_colorp background; - /* Local variables: */ - png_voidp local_row; - png_voidp first_row; - ptrdiff_t row_bytes; /* step between rows */ - int file_encoding; /* E_ values above */ - png_fixed_point gamma_to_linear; /* For P_FILE, reciprocal of gamma */ - int colormap_processing; /* PNG_CMAP_ values above */ -} png_image_read_control; - -/* Do all the *safe* initialization - 'safe' means that png_error won't be - * called, so setting up the jmp_buf is not required. This means that anything - * called from here must *not* call png_malloc - it has to call png_malloc_warn - * instead so that control is returned safely back to this routine. - */ -static int -png_image_read_init(png_imagep image) -{ - if (image->opaque == NULL) - { - png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, image, - png_safe_error, png_safe_warning); - - /* And set the rest of the structure to NULL to ensure that the various - * fields are consistent. - */ - memset(image, 0, (sizeof *image)); - image->version = PNG_IMAGE_VERSION; - - if (png_ptr != NULL) - { - png_infop info_ptr = png_create_info_struct(png_ptr); - - if (info_ptr != NULL) - { - png_controlp control = png_voidcast(png_controlp, - png_malloc_warn(png_ptr, (sizeof *control))); - - if (control != NULL) - { - memset(control, 0, (sizeof *control)); - - control->png_ptr = png_ptr; - control->info_ptr = info_ptr; - control->for_write = 0; - - image->opaque = control; - return 1; - } - - /* Error clean up */ - png_destroy_info_struct(png_ptr, &info_ptr); - } - - png_destroy_read_struct(&png_ptr, NULL, NULL); - } - - return png_image_error(image, "png_image_read: out of memory"); - } - - return png_image_error(image, "png_image_read: opaque pointer not NULL"); -} - -/* Utility to find the base format of a PNG file from a png_struct. */ -static png_uint_32 -png_image_format(png_structrp png_ptr) -{ - png_uint_32 format = 0; - - if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) - format |= PNG_FORMAT_FLAG_COLOR; - - if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) - format |= PNG_FORMAT_FLAG_ALPHA; - - /* Use png_ptr here, not info_ptr, because by examination png_handle_tRNS - * sets the png_struct fields; that's all we are interested in here. The - * precise interaction with an app call to png_set_tRNS and PNG file reading - * is unclear. - */ - else if (png_ptr->num_trans > 0) - format |= PNG_FORMAT_FLAG_ALPHA; - - if (png_ptr->bit_depth == 16) - format |= PNG_FORMAT_FLAG_LINEAR; - - if ((png_ptr->color_type & PNG_COLOR_MASK_PALETTE) != 0) - format |= PNG_FORMAT_FLAG_COLORMAP; - - return format; -} - -/* Is the given gamma significantly different from sRGB? The test is the same - * one used in pngrtran.c when deciding whether to do gamma correction. The - * arithmetic optimizes the division by using the fact that the inverse of the - * file sRGB gamma is 2.2 - */ -static int -png_gamma_not_sRGB(png_fixed_point g) -{ - if (g < PNG_FP_1) - { - /* An uninitialized gamma is assumed to be sRGB for the simplified API. */ - if (g == 0) - return 0; - - return png_gamma_significant((g * 11 + 2)/5 /* i.e. *2.2, rounded */); - } - - return 1; -} - -/* Do the main body of a 'png_image_begin_read' function; read the PNG file - * header and fill in all the information. This is executed in a safe context, - * unlike the init routine above. - */ -static int -png_image_read_header(png_voidp argument) -{ - png_imagep image = png_voidcast(png_imagep, argument); - png_structrp png_ptr = image->opaque->png_ptr; - png_inforp info_ptr = image->opaque->info_ptr; - - png_set_benign_errors(png_ptr, 1/*warn*/); - png_read_info(png_ptr, info_ptr); - - /* Do this the fast way; just read directly out of png_struct. */ - image->width = png_ptr->width; - image->height = png_ptr->height; - - { - png_uint_32 format = png_image_format(png_ptr); - - image->format = format; - -#ifdef PNG_COLORSPACE_SUPPORTED - /* Does the colorspace match sRGB? If there is no color endpoint - * (colorant) information assume yes, otherwise require the - * 'ENDPOINTS_MATCHP_sRGB' colorspace flag to have been set. If the - * colorspace has been determined to be invalid ignore it. - */ - if ((format & PNG_FORMAT_FLAG_COLOR) != 0 && ((png_ptr->colorspace.flags - & (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB| - PNG_COLORSPACE_INVALID)) == PNG_COLORSPACE_HAVE_ENDPOINTS)) - image->flags |= PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB; -#endif - } - - /* We need the maximum number of entries regardless of the format the - * application sets here. - */ - { - png_uint_32 cmap_entries; - - switch (png_ptr->color_type) - { - case PNG_COLOR_TYPE_GRAY: - cmap_entries = 1U << png_ptr->bit_depth; - break; - - case PNG_COLOR_TYPE_PALETTE: - cmap_entries = png_ptr->num_palette; - break; - - default: - cmap_entries = 256; - break; - } - - if (cmap_entries > 256) - cmap_entries = 256; - - image->colormap_entries = cmap_entries; - } - - return 1; -} - -#ifdef PNG_STDIO_SUPPORTED -int PNGAPI -png_image_begin_read_from_stdio(png_imagep image, FILE* file) -{ - if (image != NULL && image->version == PNG_IMAGE_VERSION) - { - if (file != NULL) - { - if (png_image_read_init(image) != 0) - { - /* This is slightly evil, but png_init_io doesn't do anything other - * than this and we haven't changed the standard IO functions so - * this saves a 'safe' function. - */ - image->opaque->png_ptr->io_ptr = file; - return png_safe_execute(image, png_image_read_header, image); - } - } - - else - return png_image_error(image, - "png_image_begin_read_from_stdio: invalid argument"); - } - - else if (image != NULL) - return png_image_error(image, - "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION"); - - return 0; -} - -int PNGAPI -png_image_begin_read_from_file(png_imagep image, const char *file_name) -{ - if (image != NULL && image->version == PNG_IMAGE_VERSION) - { - if (file_name != NULL) - { - FILE *fp = fopen(file_name, "rb"); - - if (fp != NULL) - { - if (png_image_read_init(image) != 0) - { - image->opaque->png_ptr->io_ptr = fp; - image->opaque->owned_file = 1; - return png_safe_execute(image, png_image_read_header, image); - } - - /* Clean up: just the opened file. */ - (void)fclose(fp); - } - - else - return png_image_error(image, strerror(errno)); - } - - else - return png_image_error(image, - "png_image_begin_read_from_file: invalid argument"); - } - - else if (image != NULL) - return png_image_error(image, - "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION"); - - return 0; -} -#endif /* STDIO */ - -static void PNGCBAPI -png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need) -{ - if (png_ptr != NULL) - { - png_imagep image = png_voidcast(png_imagep, png_ptr->io_ptr); - if (image != NULL) - { - png_controlp cp = image->opaque; - if (cp != NULL) - { - png_const_bytep memory = cp->memory; - png_size_t size = cp->size; - - if (memory != NULL && size >= need) - { - memcpy(out, memory, need); - cp->memory = memory + need; - cp->size = size - need; - return; - } - - png_error(png_ptr, "read beyond end of data"); - } - } - - png_error(png_ptr, "invalid memory read"); - } -} - -int PNGAPI png_image_begin_read_from_memory(png_imagep image, - png_const_voidp memory, png_size_t size) -{ - if (image != NULL && image->version == PNG_IMAGE_VERSION) - { - if (memory != NULL && size > 0) - { - if (png_image_read_init(image) != 0) - { - /* Now set the IO functions to read from the memory buffer and - * store it into io_ptr. Again do this in-place to avoid calling a - * libpng function that requires error handling. - */ - image->opaque->memory = png_voidcast(png_const_bytep, memory); - image->opaque->size = size; - image->opaque->png_ptr->io_ptr = image; - image->opaque->png_ptr->read_data_fn = png_image_memory_read; - - return png_safe_execute(image, png_image_read_header, image); - } - } - - else - return png_image_error(image, - "png_image_begin_read_from_memory: invalid argument"); - } - - else if (image != NULL) - return png_image_error(image, - "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION"); - - return 0; -} - -/* Utility function to skip chunks that are not used by the simplified image - * read functions and an appropriate macro to call it. - */ -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED -static void -png_image_skip_unused_chunks(png_structrp png_ptr) -{ - /* Prepare the reader to ignore all recognized chunks whose data will not - * be used, i.e., all chunks recognized by libpng except for those - * involved in basic image reading: - * - * IHDR, PLTE, IDAT, IEND - * - * Or image data handling: - * - * tRNS, bKGD, gAMA, cHRM, sRGB, [iCCP] and sBIT. - * - * This provides a small performance improvement and eliminates any - * potential vulnerability to security problems in the unused chunks. - * - * At present the iCCP chunk data isn't used, so iCCP chunk can be ignored - * too. This allows the simplified API to be compiled without iCCP support, - * however if the support is there the chunk is still checked to detect - * errors (which are unfortunately quite common.) - */ - { - static PNG_CONST png_byte chunks_to_process[] = { - 98, 75, 71, 68, '\0', /* bKGD */ - 99, 72, 82, 77, '\0', /* cHRM */ - 103, 65, 77, 65, '\0', /* gAMA */ -# ifdef PNG_READ_iCCP_SUPPORTED - 105, 67, 67, 80, '\0', /* iCCP */ -# endif - 115, 66, 73, 84, '\0', /* sBIT */ - 115, 82, 71, 66, '\0', /* sRGB */ - }; - - /* Ignore unknown chunks and all other chunks except for the - * IHDR, PLTE, tRNS, IDAT, and IEND chunks. - */ - png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER, - NULL, -1); - - /* But do not ignore image data handling chunks */ - png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT, - chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5); - } -} - -# define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p) -#else -# define PNG_SKIP_CHUNKS(p) ((void)0) -#endif /* HANDLE_AS_UNKNOWN */ - -/* The following macro gives the exact rounded answer for all values in the - * range 0..255 (it actually divides by 51.2, but the rounding still generates - * the correct numbers 0..5 - */ -#define PNG_DIV51(v8) (((v8) * 5 + 130) >> 8) - -/* Utility functions to make particular color-maps */ -static void -set_file_encoding(png_image_read_control *display) -{ - png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma; - if (png_gamma_significant(g) != 0) - { - if (png_gamma_not_sRGB(g) != 0) - { - display->file_encoding = P_FILE; - display->gamma_to_linear = png_reciprocal(g); - } - - else - display->file_encoding = P_sRGB; - } - - else - display->file_encoding = P_LINEAR8; -} - -static unsigned int -decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding) -{ - if (encoding == P_FILE) /* double check */ - encoding = display->file_encoding; - - if (encoding == P_NOTSET) /* must be the file encoding */ - { - set_file_encoding(display); - encoding = display->file_encoding; - } - - switch (encoding) - { - case P_FILE: - value = png_gamma_16bit_correct(value*257, display->gamma_to_linear); - break; - - case P_sRGB: - value = png_sRGB_table[value]; - break; - - case P_LINEAR: - break; - - case P_LINEAR8: - value *= 257; - break; - -#ifdef __GNUC__ - default: - png_error(display->image->opaque->png_ptr, - "unexpected encoding (internal error)"); -#endif - } - - return value; -} - -static png_uint_32 -png_colormap_compose(png_image_read_control *display, - png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha, - png_uint_32 background, int encoding) -{ - /* The file value is composed on the background, the background has the given - * encoding and so does the result, the file is encoded with P_FILE and the - * file and alpha are 8-bit values. The (output) encoding will always be - * P_LINEAR or P_sRGB. - */ - png_uint_32 f = decode_gamma(display, foreground, foreground_encoding); - png_uint_32 b = decode_gamma(display, background, encoding); - - /* The alpha is always an 8-bit value (it comes from the palette), the value - * scaled by 255 is what PNG_sRGB_FROM_LINEAR requires. - */ - f = f * alpha + b * (255-alpha); - - if (encoding == P_LINEAR) - { - /* Scale to 65535; divide by 255, approximately (in fact this is extremely - * accurate, it divides by 255.00000005937181414556, with no overflow.) - */ - f *= 257; /* Now scaled by 65535 */ - f += f >> 16; - f = (f+32768) >> 16; - } - - else /* P_sRGB */ - f = PNG_sRGB_FROM_LINEAR(f); - - return f; -} - -/* NOTE: P_LINEAR values to this routine must be 16-bit, but P_FILE values must - * be 8-bit. - */ -static void -png_create_colormap_entry(png_image_read_control *display, - png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue, - png_uint_32 alpha, int encoding) -{ - png_imagep image = display->image; - const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ? - P_LINEAR : P_sRGB; - const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 && - (red != green || green != blue); - - if (ip > 255) - png_error(image->opaque->png_ptr, "color-map index out of range"); - - /* Update the cache with whether the file gamma is significantly different - * from sRGB. - */ - if (encoding == P_FILE) - { - if (display->file_encoding == P_NOTSET) - set_file_encoding(display); - - /* Note that the cached value may be P_FILE too, but if it is then the - * gamma_to_linear member has been set. - */ - encoding = display->file_encoding; - } - - if (encoding == P_FILE) - { - png_fixed_point g = display->gamma_to_linear; - - red = png_gamma_16bit_correct(red*257, g); - green = png_gamma_16bit_correct(green*257, g); - blue = png_gamma_16bit_correct(blue*257, g); - - if (convert_to_Y != 0 || output_encoding == P_LINEAR) - { - alpha *= 257; - encoding = P_LINEAR; - } - - else - { - red = PNG_sRGB_FROM_LINEAR(red * 255); - green = PNG_sRGB_FROM_LINEAR(green * 255); - blue = PNG_sRGB_FROM_LINEAR(blue * 255); - encoding = P_sRGB; - } - } - - else if (encoding == P_LINEAR8) - { - /* This encoding occurs quite frequently in test cases because PngSuite - * includes a gAMA 1.0 chunk with most images. - */ - red *= 257; - green *= 257; - blue *= 257; - alpha *= 257; - encoding = P_LINEAR; - } - - else if (encoding == P_sRGB && - (convert_to_Y != 0 || output_encoding == P_LINEAR)) - { - /* The values are 8-bit sRGB values, but must be converted to 16-bit - * linear. - */ - red = png_sRGB_table[red]; - green = png_sRGB_table[green]; - blue = png_sRGB_table[blue]; - alpha *= 257; - encoding = P_LINEAR; - } - - /* This is set if the color isn't gray but the output is. */ - if (encoding == P_LINEAR) - { - if (convert_to_Y != 0) - { - /* NOTE: these values are copied from png_do_rgb_to_gray */ - png_uint_32 y = (png_uint_32)6968 * red + (png_uint_32)23434 * green + - (png_uint_32)2366 * blue; - - if (output_encoding == P_LINEAR) - y = (y + 16384) >> 15; - - else - { - /* y is scaled by 32768, we need it scaled by 255: */ - y = (y + 128) >> 8; - y *= 255; - y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7); - alpha = PNG_DIV257(alpha); - encoding = P_sRGB; - } - - blue = red = green = y; - } - - else if (output_encoding == P_sRGB) - { - red = PNG_sRGB_FROM_LINEAR(red * 255); - green = PNG_sRGB_FROM_LINEAR(green * 255); - blue = PNG_sRGB_FROM_LINEAR(blue * 255); - alpha = PNG_DIV257(alpha); - encoding = P_sRGB; - } - } - - if (encoding != output_encoding) - png_error(image->opaque->png_ptr, "bad encoding (internal error)"); - - /* Store the value. */ - { -# ifdef PNG_FORMAT_AFIRST_SUPPORTED - const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 && - (image->format & PNG_FORMAT_FLAG_ALPHA) != 0; -# else -# define afirst 0 -# endif -# ifdef PNG_FORMAT_BGR_SUPPORTED - const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; -# else -# define bgr 0 -# endif - - if (output_encoding == P_LINEAR) - { - png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap); - - entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format); - - /* The linear 16-bit values must be pre-multiplied by the alpha channel - * value, if less than 65535 (this is, effectively, composite on black - * if the alpha channel is removed.) - */ - switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format)) - { - case 4: - entry[afirst ? 0 : 3] = (png_uint_16)alpha; - /* FALL THROUGH */ - - case 3: - if (alpha < 65535) - { - if (alpha > 0) - { - blue = (blue * alpha + 32767U)/65535U; - green = (green * alpha + 32767U)/65535U; - red = (red * alpha + 32767U)/65535U; - } - - else - red = green = blue = 0; - } - entry[afirst + (2 ^ bgr)] = (png_uint_16)blue; - entry[afirst + 1] = (png_uint_16)green; - entry[afirst + bgr] = (png_uint_16)red; - break; - - case 2: - entry[1 ^ afirst] = (png_uint_16)alpha; - /* FALL THROUGH */ - - case 1: - if (alpha < 65535) - { - if (alpha > 0) - green = (green * alpha + 32767U)/65535U; - - else - green = 0; - } - entry[afirst] = (png_uint_16)green; - break; - - default: - break; - } - } - - else /* output encoding is P_sRGB */ - { - png_bytep entry = png_voidcast(png_bytep, display->colormap); - - entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format); - - switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format)) - { - case 4: - entry[afirst ? 0 : 3] = (png_byte)alpha; - case 3: - entry[afirst + (2 ^ bgr)] = (png_byte)blue; - entry[afirst + 1] = (png_byte)green; - entry[afirst + bgr] = (png_byte)red; - break; - - case 2: - entry[1 ^ afirst] = (png_byte)alpha; - case 1: - entry[afirst] = (png_byte)green; - break; - - default: - break; - } - } - -# ifdef afirst -# undef afirst -# endif -# ifdef bgr -# undef bgr -# endif - } -} - -static int -make_gray_file_colormap(png_image_read_control *display) -{ - unsigned int i; - - for (i=0; i<256; ++i) - png_create_colormap_entry(display, i, i, i, i, 255, P_FILE); - - return i; -} - -static int -make_gray_colormap(png_image_read_control *display) -{ - unsigned int i; - - for (i=0; i<256; ++i) - png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB); - - return i; -} -#define PNG_GRAY_COLORMAP_ENTRIES 256 - -static int -make_ga_colormap(png_image_read_control *display) -{ - unsigned int i, a; - - /* Alpha is retained, the output will be a color-map with entries - * selected by six levels of alpha. One transparent entry, 6 gray - * levels for all the intermediate alpha values, leaving 230 entries - * for the opaque grays. The color-map entries are the six values - * [0..5]*51, the GA processing uses PNG_DIV51(value) to find the - * relevant entry. - * - * if (alpha > 229) // opaque - * { - * // The 231 entries are selected to make the math below work: - * base = 0; - * entry = (231 * gray + 128) >> 8; - * } - * else if (alpha < 26) // transparent - * { - * base = 231; - * entry = 0; - * } - * else // partially opaque - * { - * base = 226 + 6 * PNG_DIV51(alpha); - * entry = PNG_DIV51(gray); - * } - */ - i = 0; - while (i < 231) - { - unsigned int gray = (i * 256 + 115) / 231; - png_create_colormap_entry(display, i++, gray, gray, gray, 255, P_sRGB); - } - - /* 255 is used here for the component values for consistency with the code - * that undoes premultiplication in pngwrite.c. - */ - png_create_colormap_entry(display, i++, 255, 255, 255, 0, P_sRGB); - - for (a=1; a<5; ++a) - { - unsigned int g; - - for (g=0; g<6; ++g) - png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51, - P_sRGB); - } - - return i; -} - -#define PNG_GA_COLORMAP_ENTRIES 256 - -static int -make_rgb_colormap(png_image_read_control *display) -{ - unsigned int i, r; - - /* Build a 6x6x6 opaque RGB cube */ - for (i=r=0; r<6; ++r) - { - unsigned int g; - - for (g=0; g<6; ++g) - { - unsigned int b; - - for (b=0; b<6; ++b) - png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255, - P_sRGB); - } - } - - return i; -} - -#define PNG_RGB_COLORMAP_ENTRIES 216 - -/* Return a palette index to the above palette given three 8-bit sRGB values. */ -#define PNG_RGB_INDEX(r,g,b) \ - ((png_byte)(6 * (6 * PNG_DIV51(r) + PNG_DIV51(g)) + PNG_DIV51(b))) - -static int -png_image_read_colormap(png_voidp argument) -{ - png_image_read_control *display = - png_voidcast(png_image_read_control*, argument); - const png_imagep image = display->image; - - const png_structrp png_ptr = image->opaque->png_ptr; - const png_uint_32 output_format = image->format; - const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ? - P_LINEAR : P_sRGB; - - unsigned int cmap_entries; - unsigned int output_processing; /* Output processing option */ - unsigned int data_encoding = P_NOTSET; /* Encoding libpng must produce */ - - /* Background information; the background color and the index of this color - * in the color-map if it exists (else 256). - */ - unsigned int background_index = 256; - png_uint_32 back_r, back_g, back_b; - - /* Flags to accumulate things that need to be done to the input. */ - int expand_tRNS = 0; - - /* Exclude the NYI feature of compositing onto a color-mapped buffer; it is - * very difficult to do, the results look awful, and it is difficult to see - * what possible use it is because the application can't control the - * color-map. - */ - if (((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0 || - png_ptr->num_trans > 0) /* alpha in input */ && - ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) /* no alpha in output */) - { - if (output_encoding == P_LINEAR) /* compose on black */ - back_b = back_g = back_r = 0; - - else if (display->background == NULL /* no way to remove it */) - png_error(png_ptr, - "a background color must be supplied to remove alpha/transparency"); - - /* Get a copy of the background color (this avoids repeating the checks - * below.) The encoding is 8-bit sRGB or 16-bit linear, depending on the - * output format. - */ - else - { - back_g = display->background->green; - if ((output_format & PNG_FORMAT_FLAG_COLOR) != 0) - { - back_r = display->background->red; - back_b = display->background->blue; - } - else - back_b = back_r = back_g; - } - } - - else if (output_encoding == P_LINEAR) - back_b = back_r = back_g = 65535; - - else - back_b = back_r = back_g = 255; - - /* Default the input file gamma if required - this is necessary because - * libpng assumes that if no gamma information is present the data is in the - * output format, but the simplified API deduces the gamma from the input - * format. - */ - if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) == 0) - { - /* Do this directly, not using the png_colorspace functions, to ensure - * that it happens even if the colorspace is invalid (though probably if - * it is the setting will be ignored) Note that the same thing can be - * achieved at the application interface with png_set_gAMA. - */ - if (png_ptr->bit_depth == 16 && - (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0) - png_ptr->colorspace.gamma = PNG_GAMMA_LINEAR; - - else - png_ptr->colorspace.gamma = PNG_GAMMA_sRGB_INVERSE; - - png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; - } - - /* Decide what to do based on the PNG color type of the input data. The - * utility function png_create_colormap_entry deals with most aspects of the - * output transformations; this code works out how to produce bytes of - * color-map entries from the original format. - */ - switch (png_ptr->color_type) - { - case PNG_COLOR_TYPE_GRAY: - if (png_ptr->bit_depth <= 8) - { - /* There at most 256 colors in the output, regardless of - * transparency. - */ - unsigned int step, i, val, trans = 256/*ignore*/, back_alpha = 0; - - cmap_entries = 1U << png_ptr->bit_depth; - if (cmap_entries > image->colormap_entries) - png_error(png_ptr, "gray[8] color-map: too few entries"); - - step = 255 / (cmap_entries - 1); - output_processing = PNG_CMAP_NONE; - - /* If there is a tRNS chunk then this either selects a transparent - * value or, if the output has no alpha, the background color. - */ - if (png_ptr->num_trans > 0) - { - trans = png_ptr->trans_color.gray; - - if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) - back_alpha = output_encoding == P_LINEAR ? 65535 : 255; - } - - /* png_create_colormap_entry just takes an RGBA and writes the - * corresponding color-map entry using the format from 'image', - * including the required conversion to sRGB or linear as - * appropriate. The input values are always either sRGB (if the - * gamma correction flag is 0) or 0..255 scaled file encoded values - * (if the function must gamma correct them). - */ - for (i=val=0; i<cmap_entries; ++i, val += step) - { - /* 'i' is a file value. While this will result in duplicated - * entries for 8-bit non-sRGB encoded files it is necessary to - * have non-gamma corrected values to do tRNS handling. - */ - if (i != trans) - png_create_colormap_entry(display, i, val, val, val, 255, - P_FILE/*8-bit with file gamma*/); - - /* Else this entry is transparent. The colors don't matter if - * there is an alpha channel (back_alpha == 0), but it does no - * harm to pass them in; the values are not set above so this - * passes in white. - * - * NOTE: this preserves the full precision of the application - * supplied background color when it is used. - */ - else - png_create_colormap_entry(display, i, back_r, back_g, back_b, - back_alpha, output_encoding); - } - - /* We need libpng to preserve the original encoding. */ - data_encoding = P_FILE; - - /* The rows from libpng, while technically gray values, are now also - * color-map indices; however, they may need to be expanded to 1 - * byte per pixel. This is what png_set_packing does (i.e., it - * unpacks the bit values into bytes.) - */ - if (png_ptr->bit_depth < 8) - png_set_packing(png_ptr); - } - - else /* bit depth is 16 */ - { - /* The 16-bit input values can be converted directly to 8-bit gamma - * encoded values; however, if a tRNS chunk is present 257 color-map - * entries are required. This means that the extra entry requires - * special processing; add an alpha channel, sacrifice gray level - * 254 and convert transparent (alpha==0) entries to that. - * - * Use libpng to chop the data to 8 bits. Convert it to sRGB at the - * same time to minimize quality loss. If a tRNS chunk is present - * this means libpng must handle it too; otherwise it is impossible - * to do the exact match on the 16-bit value. - * - * If the output has no alpha channel *and* the background color is - * gray then it is possible to let libpng handle the substitution by - * ensuring that the corresponding gray level matches the background - * color exactly. - */ - data_encoding = P_sRGB; - - if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) - png_error(png_ptr, "gray[16] color-map: too few entries"); - - cmap_entries = make_gray_colormap(display); - - if (png_ptr->num_trans > 0) - { - unsigned int back_alpha; - - if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) - back_alpha = 0; - - else - { - if (back_r == back_g && back_g == back_b) - { - /* Background is gray; no special processing will be - * required. - */ - png_color_16 c; - png_uint_32 gray = back_g; - - if (output_encoding == P_LINEAR) - { - gray = PNG_sRGB_FROM_LINEAR(gray * 255); - - /* And make sure the corresponding palette entry - * matches. - */ - png_create_colormap_entry(display, gray, back_g, back_g, - back_g, 65535, P_LINEAR); - } - - /* The background passed to libpng, however, must be the - * sRGB value. - */ - c.index = 0; /*unused*/ - c.gray = c.red = c.green = c.blue = (png_uint_16)gray; - - /* NOTE: does this work without expanding tRNS to alpha? - * It should be the color->gray case below apparently - * doesn't. - */ - png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); - - output_processing = PNG_CMAP_NONE; - break; - } -#ifdef __COVERITY__ - /* Coverity claims that output_encoding cannot be 2 (P_LINEAR) - * here. - */ - back_alpha = 255; -#else - back_alpha = output_encoding == P_LINEAR ? 65535 : 255; -#endif - } - - /* output_processing means that the libpng-processed row will be - * 8-bit GA and it has to be processing to single byte color-map - * values. Entry 254 is replaced by either a completely - * transparent entry or by the background color at full - * precision (and the background color is not a simple gray - * level in this case.) - */ - expand_tRNS = 1; - output_processing = PNG_CMAP_TRANS; - background_index = 254; - - /* And set (overwrite) color-map entry 254 to the actual - * background color at full precision. - */ - png_create_colormap_entry(display, 254, back_r, back_g, back_b, - back_alpha, output_encoding); - } - - else - output_processing = PNG_CMAP_NONE; - } - break; - - case PNG_COLOR_TYPE_GRAY_ALPHA: - /* 8-bit or 16-bit PNG with two channels - gray and alpha. A minimum - * of 65536 combinations. If, however, the alpha channel is to be - * removed there are only 256 possibilities if the background is gray. - * (Otherwise there is a subset of the 65536 possibilities defined by - * the triangle between black, white and the background color.) - * - * Reduce 16-bit files to 8-bit and sRGB encode the result. No need to - * worry about tRNS matching - tRNS is ignored if there is an alpha - * channel. - */ - data_encoding = P_sRGB; - - if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) - { - if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) - png_error(png_ptr, "gray+alpha color-map: too few entries"); - - cmap_entries = make_ga_colormap(display); - - background_index = PNG_CMAP_GA_BACKGROUND; - output_processing = PNG_CMAP_GA; - } - - else /* alpha is removed */ - { - /* Alpha must be removed as the PNG data is processed when the - * background is a color because the G and A channels are - * independent and the vector addition (non-parallel vectors) is a - * 2-D problem. - * - * This can be reduced to the same algorithm as above by making a - * colormap containing gray levels (for the opaque grays), a - * background entry (for a transparent pixel) and a set of four six - * level color values, one set for each intermediate alpha value. - * See the comments in make_ga_colormap for how this works in the - * per-pixel processing. - * - * If the background is gray, however, we only need a 256 entry gray - * level color map. It is sufficient to make the entry generated - * for the background color be exactly the color specified. - */ - if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0 || - (back_r == back_g && back_g == back_b)) - { - /* Background is gray; no special processing will be required. */ - png_color_16 c; - png_uint_32 gray = back_g; - - if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) - png_error(png_ptr, "gray-alpha color-map: too few entries"); - - cmap_entries = make_gray_colormap(display); - - if (output_encoding == P_LINEAR) - { - gray = PNG_sRGB_FROM_LINEAR(gray * 255); - - /* And make sure the corresponding palette entry matches. */ - png_create_colormap_entry(display, gray, back_g, back_g, - back_g, 65535, P_LINEAR); - } - - /* The background passed to libpng, however, must be the sRGB - * value. - */ - c.index = 0; /*unused*/ - c.gray = c.red = c.green = c.blue = (png_uint_16)gray; - - png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); - - output_processing = PNG_CMAP_NONE; - } - - else - { - png_uint_32 i, a; - - /* This is the same as png_make_ga_colormap, above, except that - * the entries are all opaque. - */ - if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) - png_error(png_ptr, "ga-alpha color-map: too few entries"); - - i = 0; - while (i < 231) - { - png_uint_32 gray = (i * 256 + 115) / 231; - png_create_colormap_entry(display, i++, gray, gray, gray, - 255, P_sRGB); - } - - /* NOTE: this preserves the full precision of the application - * background color. - */ - background_index = i; - png_create_colormap_entry(display, i++, back_r, back_g, back_b, -#ifdef __COVERITY__ - /* Coverity claims that output_encoding cannot be 2 (P_LINEAR) - * here. - */ 255U, -#else - output_encoding == P_LINEAR ? 65535U : 255U, -#endif - output_encoding); - - /* For non-opaque input composite on the sRGB background - this - * requires inverting the encoding for each component. The input - * is still converted to the sRGB encoding because this is a - * reasonable approximate to the logarithmic curve of human - * visual sensitivity, at least over the narrow range which PNG - * represents. Consequently 'G' is always sRGB encoded, while - * 'A' is linear. We need the linear background colors. - */ - if (output_encoding == P_sRGB) /* else already linear */ - { - /* This may produce a value not exactly matching the - * background, but that's ok because these numbers are only - * used when alpha != 0 - */ - back_r = png_sRGB_table[back_r]; - back_g = png_sRGB_table[back_g]; - back_b = png_sRGB_table[back_b]; - } - - for (a=1; a<5; ++a) - { - unsigned int g; - - /* PNG_sRGB_FROM_LINEAR expects a 16-bit linear value scaled - * by an 8-bit alpha value (0..255). - */ - png_uint_32 alpha = 51 * a; - png_uint_32 back_rx = (255-alpha) * back_r; - png_uint_32 back_gx = (255-alpha) * back_g; - png_uint_32 back_bx = (255-alpha) * back_b; - - for (g=0; g<6; ++g) - { - png_uint_32 gray = png_sRGB_table[g*51] * alpha; - - png_create_colormap_entry(display, i++, - PNG_sRGB_FROM_LINEAR(gray + back_rx), - PNG_sRGB_FROM_LINEAR(gray + back_gx), - PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB); - } - } - - cmap_entries = i; - output_processing = PNG_CMAP_GA; - } - } - break; - - case PNG_COLOR_TYPE_RGB: - case PNG_COLOR_TYPE_RGB_ALPHA: - /* Exclude the case where the output is gray; we can always handle this - * with the cases above. - */ - if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0) - { - /* The color-map will be grayscale, so we may as well convert the - * input RGB values to a simple grayscale and use the grayscale - * code above. - * - * NOTE: calling this apparently damages the recognition of the - * transparent color in background color handling; call - * png_set_tRNS_to_alpha before png_set_background_fixed. - */ - png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1, - -1); - data_encoding = P_sRGB; - - /* The output will now be one or two 8-bit gray or gray+alpha - * channels. The more complex case arises when the input has alpha. - */ - if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - png_ptr->num_trans > 0) && - (output_format & PNG_FORMAT_FLAG_ALPHA) != 0) - { - /* Both input and output have an alpha channel, so no background - * processing is required; just map the GA bytes to the right - * color-map entry. - */ - expand_tRNS = 1; - - if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) - png_error(png_ptr, "rgb[ga] color-map: too few entries"); - - cmap_entries = make_ga_colormap(display); - background_index = PNG_CMAP_GA_BACKGROUND; - output_processing = PNG_CMAP_GA; - } - - else - { - /* Either the input or the output has no alpha channel, so there - * will be no non-opaque pixels in the color-map; it will just be - * grayscale. - */ - if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) - png_error(png_ptr, "rgb[gray] color-map: too few entries"); - - /* Ideally this code would use libpng to do the gamma correction, - * but if an input alpha channel is to be removed we will hit the - * libpng bug in gamma+compose+rgb-to-gray (the double gamma - * correction bug). Fix this by dropping the gamma correction in - * this case and doing it in the palette; this will result in - * duplicate palette entries, but that's better than the - * alternative of double gamma correction. - */ - if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - png_ptr->num_trans > 0) && - png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0) - { - cmap_entries = make_gray_file_colormap(display); - data_encoding = P_FILE; - } - - else - cmap_entries = make_gray_colormap(display); - - /* But if the input has alpha or transparency it must be removed - */ - if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - png_ptr->num_trans > 0) - { - png_color_16 c; - png_uint_32 gray = back_g; - - /* We need to ensure that the application background exists in - * the colormap and that completely transparent pixels map to - * it. Achieve this simply by ensuring that the entry - * selected for the background really is the background color. - */ - if (data_encoding == P_FILE) /* from the fixup above */ - { - /* The app supplied a gray which is in output_encoding, we - * need to convert it to a value of the input (P_FILE) - * encoding then set this palette entry to the required - * output encoding. - */ - if (output_encoding == P_sRGB) - gray = png_sRGB_table[gray]; /* now P_LINEAR */ - - gray = PNG_DIV257(png_gamma_16bit_correct(gray, - png_ptr->colorspace.gamma)); /* now P_FILE */ - - /* And make sure the corresponding palette entry contains - * exactly the required sRGB value. - */ - png_create_colormap_entry(display, gray, back_g, back_g, - back_g, 0/*unused*/, output_encoding); - } - - else if (output_encoding == P_LINEAR) - { - gray = PNG_sRGB_FROM_LINEAR(gray * 255); - - /* And make sure the corresponding palette entry matches. - */ - png_create_colormap_entry(display, gray, back_g, back_g, - back_g, 0/*unused*/, P_LINEAR); - } - - /* The background passed to libpng, however, must be the - * output (normally sRGB) value. - */ - c.index = 0; /*unused*/ - c.gray = c.red = c.green = c.blue = (png_uint_16)gray; - - /* NOTE: the following is apparently a bug in libpng. Without - * it the transparent color recognition in - * png_set_background_fixed seems to go wrong. - */ - expand_tRNS = 1; - png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); - } - - output_processing = PNG_CMAP_NONE; - } - } - - else /* output is color */ - { - /* We could use png_quantize here so long as there is no transparent - * color or alpha; png_quantize ignores alpha. Easier overall just - * to do it once and using PNG_DIV51 on the 6x6x6 reduced RGB cube. - * Consequently we always want libpng to produce sRGB data. - */ - data_encoding = P_sRGB; - - /* Is there any transparency or alpha? */ - if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - png_ptr->num_trans > 0) - { - /* Is there alpha in the output too? If so all four channels are - * processed into a special RGB cube with alpha support. - */ - if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) - { - png_uint_32 r; - - if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries) - png_error(png_ptr, "rgb+alpha color-map: too few entries"); - - cmap_entries = make_rgb_colormap(display); - - /* Add a transparent entry. */ - png_create_colormap_entry(display, cmap_entries, 255, 255, - 255, 0, P_sRGB); - - /* This is stored as the background index for the processing - * algorithm. - */ - background_index = cmap_entries++; - - /* Add 27 r,g,b entries each with alpha 0.5. */ - for (r=0; r<256; r = (r << 1) | 0x7f) - { - png_uint_32 g; - - for (g=0; g<256; g = (g << 1) | 0x7f) - { - png_uint_32 b; - - /* This generates components with the values 0, 127 and - * 255 - */ - for (b=0; b<256; b = (b << 1) | 0x7f) - png_create_colormap_entry(display, cmap_entries++, - r, g, b, 128, P_sRGB); - } - } - - expand_tRNS = 1; - output_processing = PNG_CMAP_RGB_ALPHA; - } - - else - { - /* Alpha/transparency must be removed. The background must - * exist in the color map (achieved by setting adding it after - * the 666 color-map). If the standard processing code will - * pick up this entry automatically that's all that is - * required; libpng can be called to do the background - * processing. - */ - unsigned int sample_size = - PNG_IMAGE_SAMPLE_SIZE(output_format); - png_uint_32 r, g, b; /* sRGB background */ - - if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries) - png_error(png_ptr, "rgb-alpha color-map: too few entries"); - - cmap_entries = make_rgb_colormap(display); - - png_create_colormap_entry(display, cmap_entries, back_r, - back_g, back_b, 0/*unused*/, output_encoding); - - if (output_encoding == P_LINEAR) - { - r = PNG_sRGB_FROM_LINEAR(back_r * 255); - g = PNG_sRGB_FROM_LINEAR(back_g * 255); - b = PNG_sRGB_FROM_LINEAR(back_b * 255); - } - - else - { - r = back_r; - g = back_g; - b = back_g; - } - - /* Compare the newly-created color-map entry with the one the - * PNG_CMAP_RGB algorithm will use. If the two entries don't - * match, add the new one and set this as the background - * index. - */ - if (memcmp((png_const_bytep)display->colormap + - sample_size * cmap_entries, - (png_const_bytep)display->colormap + - sample_size * PNG_RGB_INDEX(r,g,b), - sample_size) != 0) - { - /* The background color must be added. */ - background_index = cmap_entries++; - - /* Add 27 r,g,b entries each with created by composing with - * the background at alpha 0.5. - */ - for (r=0; r<256; r = (r << 1) | 0x7f) - { - for (g=0; g<256; g = (g << 1) | 0x7f) - { - /* This generates components with the values 0, 127 - * and 255 - */ - for (b=0; b<256; b = (b << 1) | 0x7f) - png_create_colormap_entry(display, cmap_entries++, - png_colormap_compose(display, r, P_sRGB, 128, - back_r, output_encoding), - png_colormap_compose(display, g, P_sRGB, 128, - back_g, output_encoding), - png_colormap_compose(display, b, P_sRGB, 128, - back_b, output_encoding), - 0/*unused*/, output_encoding); - } - } - - expand_tRNS = 1; - output_processing = PNG_CMAP_RGB_ALPHA; - } - - else /* background color is in the standard color-map */ - { - png_color_16 c; - - c.index = 0; /*unused*/ - c.red = (png_uint_16)back_r; - c.gray = c.green = (png_uint_16)back_g; - c.blue = (png_uint_16)back_b; - - png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); - - output_processing = PNG_CMAP_RGB; - } - } - } - - else /* no alpha or transparency in the input */ - { - /* Alpha in the output is irrelevant, simply map the opaque input - * pixels to the 6x6x6 color-map. - */ - if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries) - png_error(png_ptr, "rgb color-map: too few entries"); - - cmap_entries = make_rgb_colormap(display); - output_processing = PNG_CMAP_RGB; - } - } - break; - - case PNG_COLOR_TYPE_PALETTE: - /* It's already got a color-map. It may be necessary to eliminate the - * tRNS entries though. - */ - { - unsigned int num_trans = png_ptr->num_trans; - png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL; - png_const_colorp colormap = png_ptr->palette; - const int do_background = trans != NULL && - (output_format & PNG_FORMAT_FLAG_ALPHA) == 0; - unsigned int i; - - /* Just in case: */ - if (trans == NULL) - num_trans = 0; - - output_processing = PNG_CMAP_NONE; - data_encoding = P_FILE; /* Don't change from color-map indices */ - cmap_entries = png_ptr->num_palette; - if (cmap_entries > 256) - cmap_entries = 256; - - if (cmap_entries > image->colormap_entries) - png_error(png_ptr, "palette color-map: too few entries"); - - for (i=0; i < cmap_entries; ++i) - { - if (do_background != 0 && i < num_trans && trans[i] < 255) - { - if (trans[i] == 0) - png_create_colormap_entry(display, i, back_r, back_g, - back_b, 0, output_encoding); - - else - { - /* Must compose the PNG file color in the color-map entry - * on the sRGB color in 'back'. - */ - png_create_colormap_entry(display, i, - png_colormap_compose(display, colormap[i].red, P_FILE, - trans[i], back_r, output_encoding), - png_colormap_compose(display, colormap[i].green, P_FILE, - trans[i], back_g, output_encoding), - png_colormap_compose(display, colormap[i].blue, P_FILE, - trans[i], back_b, output_encoding), - output_encoding == P_LINEAR ? trans[i] * 257U : - trans[i], - output_encoding); - } - } - - else - png_create_colormap_entry(display, i, colormap[i].red, - colormap[i].green, colormap[i].blue, - i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/); - } - - /* The PNG data may have indices packed in fewer than 8 bits, it - * must be expanded if so. - */ - if (png_ptr->bit_depth < 8) - png_set_packing(png_ptr); - } - break; - - default: - png_error(png_ptr, "invalid PNG color type"); - /*NOT REACHED*/ - } - - /* Now deal with the output processing */ - if (expand_tRNS != 0 && png_ptr->num_trans > 0 && - (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0) - png_set_tRNS_to_alpha(png_ptr); - - switch (data_encoding) - { - case P_sRGB: - /* Change to 8-bit sRGB */ - png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB); - /* FALL THROUGH */ - - case P_FILE: - if (png_ptr->bit_depth > 8) - png_set_scale_16(png_ptr); - break; - -#ifdef __GNUC__ - default: - png_error(png_ptr, "bad data option (internal error)"); -#endif - } - - if (cmap_entries > 256 || cmap_entries > image->colormap_entries) - png_error(png_ptr, "color map overflow (BAD internal error)"); - - image->colormap_entries = cmap_entries; - - /* Double check using the recorded background index */ - switch (output_processing) - { - case PNG_CMAP_NONE: - if (background_index != PNG_CMAP_NONE_BACKGROUND) - goto bad_background; - break; - - case PNG_CMAP_GA: - if (background_index != PNG_CMAP_GA_BACKGROUND) - goto bad_background; - break; - - case PNG_CMAP_TRANS: - if (background_index >= cmap_entries || - background_index != PNG_CMAP_TRANS_BACKGROUND) - goto bad_background; - break; - - case PNG_CMAP_RGB: - if (background_index != PNG_CMAP_RGB_BACKGROUND) - goto bad_background; - break; - - case PNG_CMAP_RGB_ALPHA: - if (background_index != PNG_CMAP_RGB_ALPHA_BACKGROUND) - goto bad_background; - break; - - default: - png_error(png_ptr, "bad processing option (internal error)"); - - bad_background: - png_error(png_ptr, "bad background index (internal error)"); - } - - display->colormap_processing = output_processing; - - return 1/*ok*/; -} - -/* The final part of the color-map read called from png_image_finish_read. */ -static int -png_image_read_and_map(png_voidp argument) -{ - png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); - png_imagep image = display->image; - png_structrp png_ptr = image->opaque->png_ptr; - int passes; - - /* Called when the libpng data must be transformed into the color-mapped - * form. There is a local row buffer in display->local and this routine must - * do the interlace handling. - */ - switch (png_ptr->interlaced) - { - case PNG_INTERLACE_NONE: - passes = 1; - break; - - case PNG_INTERLACE_ADAM7: - passes = PNG_INTERLACE_ADAM7_PASSES; - break; - - default: - png_error(png_ptr, "unknown interlace type"); - } - - { - png_uint_32 height = image->height; - png_uint_32 width = image->width; - int proc = display->colormap_processing; - png_bytep first_row = png_voidcast(png_bytep, display->first_row); - ptrdiff_t step_row = display->row_bytes; - int pass; - - for (pass = 0; pass < passes; ++pass) - { - unsigned int startx, stepx, stepy; - png_uint_32 y; - - if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) - { - /* The row may be empty for a short image: */ - if (PNG_PASS_COLS(width, pass) == 0) - continue; - - startx = PNG_PASS_START_COL(pass); - stepx = PNG_PASS_COL_OFFSET(pass); - y = PNG_PASS_START_ROW(pass); - stepy = PNG_PASS_ROW_OFFSET(pass); - } - - else - { - y = 0; - startx = 0; - stepx = stepy = 1; - } - - for (; y<height; y += stepy) - { - png_bytep inrow = png_voidcast(png_bytep, display->local_row); - png_bytep outrow = first_row + y * step_row; - png_const_bytep end_row = outrow + width; - - /* Read read the libpng data into the temporary buffer. */ - png_read_row(png_ptr, inrow, NULL); - - /* Now process the row according to the processing option, note - * that the caller verifies that the format of the libpng output - * data is as required. - */ - outrow += startx; - switch (proc) - { - case PNG_CMAP_GA: - for (; outrow < end_row; outrow += stepx) - { - /* The data is always in the PNG order */ - unsigned int gray = *inrow++; - unsigned int alpha = *inrow++; - unsigned int entry; - - /* NOTE: this code is copied as a comment in - * make_ga_colormap above. Please update the - * comment if you change this code! - */ - if (alpha > 229) /* opaque */ - { - entry = (231 * gray + 128) >> 8; - } - else if (alpha < 26) /* transparent */ - { - entry = 231; - } - else /* partially opaque */ - { - entry = 226 + 6 * PNG_DIV51(alpha) + PNG_DIV51(gray); - } - - *outrow = (png_byte)entry; - } - break; - - case PNG_CMAP_TRANS: - for (; outrow < end_row; outrow += stepx) - { - png_byte gray = *inrow++; - png_byte alpha = *inrow++; - - if (alpha == 0) - *outrow = PNG_CMAP_TRANS_BACKGROUND; - - else if (gray != PNG_CMAP_TRANS_BACKGROUND) - *outrow = gray; - - else - *outrow = (png_byte)(PNG_CMAP_TRANS_BACKGROUND+1); - } - break; - - case PNG_CMAP_RGB: - for (; outrow < end_row; outrow += stepx) - { - *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], inrow[2]); - inrow += 3; - } - break; - - case PNG_CMAP_RGB_ALPHA: - for (; outrow < end_row; outrow += stepx) - { - unsigned int alpha = inrow[3]; - - /* Because the alpha entries only hold alpha==0.5 values - * split the processing at alpha==0.25 (64) and 0.75 - * (196). - */ - - if (alpha >= 196) - *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], - inrow[2]); - - else if (alpha < 64) - *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND; - - else - { - /* Likewise there are three entries for each of r, g - * and b. We could select the entry by popcount on - * the top two bits on those architectures that - * support it, this is what the code below does, - * crudely. - */ - unsigned int back_i = PNG_CMAP_RGB_ALPHA_BACKGROUND+1; - - /* Here are how the values map: - * - * 0x00 .. 0x3f -> 0 - * 0x40 .. 0xbf -> 1 - * 0xc0 .. 0xff -> 2 - * - * So, as above with the explicit alpha checks, the - * breakpoints are at 64 and 196. - */ - if (inrow[0] & 0x80) back_i += 9; /* red */ - if (inrow[0] & 0x40) back_i += 9; - if (inrow[0] & 0x80) back_i += 3; /* green */ - if (inrow[0] & 0x40) back_i += 3; - if (inrow[0] & 0x80) back_i += 1; /* blue */ - if (inrow[0] & 0x40) back_i += 1; - - *outrow = (png_byte)back_i; - } - - inrow += 4; - } - break; - - default: - break; - } - } - } - } - - return 1; -} - -static int -png_image_read_colormapped(png_voidp argument) -{ - png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); - png_imagep image = display->image; - png_controlp control = image->opaque; - png_structrp png_ptr = control->png_ptr; - png_inforp info_ptr = control->info_ptr; - - int passes = 0; /* As a flag */ - - PNG_SKIP_CHUNKS(png_ptr); - - /* Update the 'info' structure and make sure the result is as required; first - * make sure to turn on the interlace handling if it will be required - * (because it can't be turned on *after* the call to png_read_update_info!) - */ - if (display->colormap_processing == PNG_CMAP_NONE) - passes = png_set_interlace_handling(png_ptr); - - png_read_update_info(png_ptr, info_ptr); - - /* The expected output can be deduced from the colormap_processing option. */ - switch (display->colormap_processing) - { - case PNG_CMAP_NONE: - /* Output must be one channel and one byte per pixel, the output - * encoding can be anything. - */ - if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE || - info_ptr->color_type == PNG_COLOR_TYPE_GRAY) && - info_ptr->bit_depth == 8) - break; - - goto bad_output; - - case PNG_CMAP_TRANS: - case PNG_CMAP_GA: - /* Output must be two channels and the 'G' one must be sRGB, the latter - * can be checked with an exact number because it should have been set - * to this number above! - */ - if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && - info_ptr->bit_depth == 8 && - png_ptr->screen_gamma == PNG_GAMMA_sRGB && - image->colormap_entries == 256) - break; - - goto bad_output; - - case PNG_CMAP_RGB: - /* Output must be 8-bit sRGB encoded RGB */ - if (info_ptr->color_type == PNG_COLOR_TYPE_RGB && - info_ptr->bit_depth == 8 && - png_ptr->screen_gamma == PNG_GAMMA_sRGB && - image->colormap_entries == 216) - break; - - goto bad_output; - - case PNG_CMAP_RGB_ALPHA: - /* Output must be 8-bit sRGB encoded RGBA */ - if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA && - info_ptr->bit_depth == 8 && - png_ptr->screen_gamma == PNG_GAMMA_sRGB && - image->colormap_entries == 244 /* 216 + 1 + 27 */) - break; - - /* goto bad_output; */ - /* FALL THROUGH */ - - default: - bad_output: - png_error(png_ptr, "bad color-map processing (internal error)"); - } - - /* Now read the rows. Do this here if it is possible to read directly into - * the output buffer, otherwise allocate a local row buffer of the maximum - * size libpng requires and call the relevant processing routine safely. - */ - { - png_voidp first_row = display->buffer; - ptrdiff_t row_bytes = display->row_stride; - - /* The following expression is designed to work correctly whether it gives - * a signed or an unsigned result. - */ - if (row_bytes < 0) - { - char *ptr = png_voidcast(char*, first_row); - ptr += (image->height-1) * (-row_bytes); - first_row = png_voidcast(png_voidp, ptr); - } - - display->first_row = first_row; - display->row_bytes = row_bytes; - } - - if (passes == 0) - { - int result; - png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); - - display->local_row = row; - result = png_safe_execute(image, png_image_read_and_map, display); - display->local_row = NULL; - png_free(png_ptr, row); - - return result; - } - - else - { - png_alloc_size_t row_bytes = display->row_bytes; - - while (--passes >= 0) - { - png_uint_32 y = image->height; - png_bytep row = png_voidcast(png_bytep, display->first_row); - - while (y-- > 0) - { - png_read_row(png_ptr, row, NULL); - row += row_bytes; - } - } - - return 1; - } -} - -/* Just the row reading part of png_image_read. */ -static int -png_image_read_composite(png_voidp argument) -{ - png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); - png_imagep image = display->image; - png_structrp png_ptr = image->opaque->png_ptr; - int passes; - - switch (png_ptr->interlaced) - { - case PNG_INTERLACE_NONE: - passes = 1; - break; - - case PNG_INTERLACE_ADAM7: - passes = PNG_INTERLACE_ADAM7_PASSES; - break; - - default: - png_error(png_ptr, "unknown interlace type"); - } - - { - png_uint_32 height = image->height; - png_uint_32 width = image->width; - ptrdiff_t step_row = display->row_bytes; - unsigned int channels = - (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; - int pass; - - for (pass = 0; pass < passes; ++pass) - { - unsigned int startx, stepx, stepy; - png_uint_32 y; - - if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) - { - /* The row may be empty for a short image: */ - if (PNG_PASS_COLS(width, pass) == 0) - continue; - - startx = PNG_PASS_START_COL(pass) * channels; - stepx = PNG_PASS_COL_OFFSET(pass) * channels; - y = PNG_PASS_START_ROW(pass); - stepy = PNG_PASS_ROW_OFFSET(pass); - } - - else - { - y = 0; - startx = 0; - stepx = channels; - stepy = 1; - } - - for (; y<height; y += stepy) - { - png_bytep inrow = png_voidcast(png_bytep, display->local_row); - png_bytep outrow; - png_const_bytep end_row; - - /* Read the row, which is packed: */ - png_read_row(png_ptr, inrow, NULL); - - outrow = png_voidcast(png_bytep, display->first_row); - outrow += y * step_row; - end_row = outrow + width * channels; - - /* Now do the composition on each pixel in this row. */ - outrow += startx; - for (; outrow < end_row; outrow += stepx) - { - png_byte alpha = inrow[channels]; - - if (alpha > 0) /* else no change to the output */ - { - unsigned int c; - - for (c=0; c<channels; ++c) - { - png_uint_32 component = inrow[c]; - - if (alpha < 255) /* else just use component */ - { - /* This is PNG_OPTIMIZED_ALPHA, the component value - * is a linear 8-bit value. Combine this with the - * current outrow[c] value which is sRGB encoded. - * Arithmetic here is 16-bits to preserve the output - * values correctly. - */ - component *= 257*255; /* =65535 */ - component += (255-alpha)*png_sRGB_table[outrow[c]]; - - /* So 'component' is scaled by 255*65535 and is - * therefore appropriate for the sRGB to linear - * conversion table. - */ - component = PNG_sRGB_FROM_LINEAR(component); - } - - outrow[c] = (png_byte)component; - } - } - - inrow += channels+1; /* components and alpha channel */ - } - } - } - } - - return 1; -} - -/* The do_local_background case; called when all the following transforms are to - * be done: - * - * PNG_RGB_TO_GRAY - * PNG_COMPOSITE - * PNG_GAMMA - * - * This is a work-around for the fact that both the PNG_RGB_TO_GRAY and - * PNG_COMPOSITE code performs gamma correction, so we get double gamma - * correction. The fix-up is to prevent the PNG_COMPOSITE operation from - * happening inside libpng, so this routine sees an 8 or 16-bit gray+alpha - * row and handles the removal or pre-multiplication of the alpha channel. - */ -static int -png_image_read_background(png_voidp argument) -{ - png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); - png_imagep image = display->image; - png_structrp png_ptr = image->opaque->png_ptr; - png_inforp info_ptr = image->opaque->info_ptr; - png_uint_32 height = image->height; - png_uint_32 width = image->width; - int pass, passes; - - /* Double check the convoluted logic below. We expect to get here with - * libpng doing rgb to gray and gamma correction but background processing - * left to the png_image_read_background function. The rows libpng produce - * might be 8 or 16-bit but should always have two channels; gray plus alpha. - */ - if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) - png_error(png_ptr, "lost rgb to gray"); - - if ((png_ptr->transformations & PNG_COMPOSE) != 0) - png_error(png_ptr, "unexpected compose"); - - if (png_get_channels(png_ptr, info_ptr) != 2) - png_error(png_ptr, "lost/gained channels"); - - /* Expect the 8-bit case to always remove the alpha channel */ - if ((image->format & PNG_FORMAT_FLAG_LINEAR) == 0 && - (image->format & PNG_FORMAT_FLAG_ALPHA) != 0) - png_error(png_ptr, "unexpected 8-bit transformation"); - - switch (png_ptr->interlaced) - { - case PNG_INTERLACE_NONE: - passes = 1; - break; - - case PNG_INTERLACE_ADAM7: - passes = PNG_INTERLACE_ADAM7_PASSES; - break; - - default: - png_error(png_ptr, "unknown interlace type"); - } - - /* Use direct access to info_ptr here because otherwise the simplified API - * would require PNG_EASY_ACCESS_SUPPORTED (just for this.) Note this is - * checking the value after libpng expansions, not the original value in the - * PNG. - */ - switch (info_ptr->bit_depth) - { - case 8: - /* 8-bit sRGB gray values with an alpha channel; the alpha channel is - * to be removed by composing on a background: either the row if - * display->background is NULL or display->background->green if not. - * Unlike the code above ALPHA_OPTIMIZED has *not* been done. - */ - { - png_bytep first_row = png_voidcast(png_bytep, display->first_row); - ptrdiff_t step_row = display->row_bytes; - - for (pass = 0; pass < passes; ++pass) - { - png_bytep row = png_voidcast(png_bytep, - display->first_row); - unsigned int startx, stepx, stepy; - png_uint_32 y; - - if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) - { - /* The row may be empty for a short image: */ - if (PNG_PASS_COLS(width, pass) == 0) - continue; - - startx = PNG_PASS_START_COL(pass); - stepx = PNG_PASS_COL_OFFSET(pass); - y = PNG_PASS_START_ROW(pass); - stepy = PNG_PASS_ROW_OFFSET(pass); - } - - else - { - y = 0; - startx = 0; - stepx = stepy = 1; - } - - if (display->background == NULL) - { - for (; y<height; y += stepy) - { - png_bytep inrow = png_voidcast(png_bytep, - display->local_row); - png_bytep outrow = first_row + y * step_row; - png_const_bytep end_row = outrow + width; - - /* Read the row, which is packed: */ - png_read_row(png_ptr, inrow, NULL); - - /* Now do the composition on each pixel in this row. */ - outrow += startx; - for (; outrow < end_row; outrow += stepx) - { - png_byte alpha = inrow[1]; - - if (alpha > 0) /* else no change to the output */ - { - png_uint_32 component = inrow[0]; - - if (alpha < 255) /* else just use component */ - { - /* Since PNG_OPTIMIZED_ALPHA was not set it is - * necessary to invert the sRGB transfer - * function and multiply the alpha out. - */ - component = png_sRGB_table[component] * alpha; - component += png_sRGB_table[outrow[0]] * - (255-alpha); - component = PNG_sRGB_FROM_LINEAR(component); - } - - outrow[0] = (png_byte)component; - } - - inrow += 2; /* gray and alpha channel */ - } - } - } - - else /* constant background value */ - { - png_byte background8 = display->background->green; - png_uint_16 background = png_sRGB_table[background8]; - - for (; y<height; y += stepy) - { - png_bytep inrow = png_voidcast(png_bytep, - display->local_row); - png_bytep outrow = first_row + y * step_row; - png_const_bytep end_row = outrow + width; - - /* Read the row, which is packed: */ - png_read_row(png_ptr, inrow, NULL); - - /* Now do the composition on each pixel in this row. */ - outrow += startx; - for (; outrow < end_row; outrow += stepx) - { - png_byte alpha = inrow[1]; - - if (alpha > 0) /* else use background */ - { - png_uint_32 component = inrow[0]; - - if (alpha < 255) /* else just use component */ - { - component = png_sRGB_table[component] * alpha; - component += background * (255-alpha); - component = PNG_sRGB_FROM_LINEAR(component); - } - - outrow[0] = (png_byte)component; - } - - else - outrow[0] = background8; - - inrow += 2; /* gray and alpha channel */ - } - - row += display->row_bytes; - } - } - } - } - break; - - case 16: - /* 16-bit linear with pre-multiplied alpha; the pre-multiplication must - * still be done and, maybe, the alpha channel removed. This code also - * handles the alpha-first option. - */ - { - png_uint_16p first_row = png_voidcast(png_uint_16p, - display->first_row); - /* The division by two is safe because the caller passed in a - * stride which was multiplied by 2 (below) to get row_bytes. - */ - ptrdiff_t step_row = display->row_bytes / 2; - int preserve_alpha = (image->format & PNG_FORMAT_FLAG_ALPHA) != 0; - unsigned int outchannels = 1+preserve_alpha; - int swap_alpha = 0; - -# ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED - if (preserve_alpha != 0 && - (image->format & PNG_FORMAT_FLAG_AFIRST) != 0) - swap_alpha = 1; -# endif - - for (pass = 0; pass < passes; ++pass) - { - unsigned int startx, stepx, stepy; - png_uint_32 y; - - /* The 'x' start and step are adjusted to output components here. - */ - if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) - { - /* The row may be empty for a short image: */ - if (PNG_PASS_COLS(width, pass) == 0) - continue; - - startx = PNG_PASS_START_COL(pass) * outchannels; - stepx = PNG_PASS_COL_OFFSET(pass) * outchannels; - y = PNG_PASS_START_ROW(pass); - stepy = PNG_PASS_ROW_OFFSET(pass); - } - - else - { - y = 0; - startx = 0; - stepx = outchannels; - stepy = 1; - } - - for (; y<height; y += stepy) - { - png_const_uint_16p inrow; - png_uint_16p outrow = first_row + y*step_row; - png_uint_16p end_row = outrow + width * outchannels; - - /* Read the row, which is packed: */ - png_read_row(png_ptr, png_voidcast(png_bytep, - display->local_row), NULL); - inrow = png_voidcast(png_const_uint_16p, display->local_row); - - /* Now do the pre-multiplication on each pixel in this row. - */ - outrow += startx; - for (; outrow < end_row; outrow += stepx) - { - png_uint_32 component = inrow[0]; - png_uint_16 alpha = inrow[1]; - - if (alpha > 0) /* else 0 */ - { - if (alpha < 65535) /* else just use component */ - { - component *= alpha; - component += 32767; - component /= 65535; - } - } - - else - component = 0; - - outrow[swap_alpha] = (png_uint_16)component; - if (preserve_alpha != 0) - outrow[1 ^ swap_alpha] = alpha; - - inrow += 2; /* components and alpha channel */ - } - } - } - } - break; - -#ifdef __GNUC__ - default: - png_error(png_ptr, "unexpected bit depth"); -#endif - } - - return 1; -} - -/* The guts of png_image_finish_read as a png_safe_execute callback. */ -static int -png_image_read_direct(png_voidp argument) -{ - png_image_read_control *display = png_voidcast(png_image_read_control*, - argument); - png_imagep image = display->image; - png_structrp png_ptr = image->opaque->png_ptr; - png_inforp info_ptr = image->opaque->info_ptr; - - png_uint_32 format = image->format; - int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0; - int do_local_compose = 0; - int do_local_background = 0; /* to avoid double gamma correction bug */ - int passes = 0; - - /* Add transforms to ensure the correct output format is produced then check - * that the required implementation support is there. Always expand; always - * need 8 bits minimum, no palette and expanded tRNS. - */ - png_set_expand(png_ptr); - - /* Now check the format to see if it was modified. */ - { - png_uint_32 base_format = png_image_format(png_ptr) & - ~PNG_FORMAT_FLAG_COLORMAP /* removed by png_set_expand */; - png_uint_32 change = format ^ base_format; - png_fixed_point output_gamma; - int mode; /* alpha mode */ - - /* Do this first so that we have a record if rgb to gray is happening. */ - if ((change & PNG_FORMAT_FLAG_COLOR) != 0) - { - /* gray<->color transformation required. */ - if ((format & PNG_FORMAT_FLAG_COLOR) != 0) - png_set_gray_to_rgb(png_ptr); - - else - { - /* libpng can't do both rgb to gray and - * background/pre-multiplication if there is also significant gamma - * correction, because both operations require linear colors and - * the code only supports one transform doing the gamma correction. - * Handle this by doing the pre-multiplication or background - * operation in this code, if necessary. - * - * TODO: fix this by rewriting pngrtran.c (!) - * - * For the moment (given that fixing this in pngrtran.c is an - * enormous change) 'do_local_background' is used to indicate that - * the problem exists. - */ - if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) - do_local_background = 1/*maybe*/; - - png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, - PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT); - } - - change &= ~PNG_FORMAT_FLAG_COLOR; - } - - /* Set the gamma appropriately, linear for 16-bit input, sRGB otherwise. - */ - { - png_fixed_point input_gamma_default; - - if ((base_format & PNG_FORMAT_FLAG_LINEAR) != 0 && - (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0) - input_gamma_default = PNG_GAMMA_LINEAR; - else - input_gamma_default = PNG_DEFAULT_sRGB; - - /* Call png_set_alpha_mode to set the default for the input gamma; the - * output gamma is set by a second call below. - */ - png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default); - } - - if (linear != 0) - { - /* If there *is* an alpha channel in the input it must be multiplied - * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG. - */ - if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) - mode = PNG_ALPHA_STANDARD; /* associated alpha */ - - else - mode = PNG_ALPHA_PNG; - - output_gamma = PNG_GAMMA_LINEAR; - } - - else - { - mode = PNG_ALPHA_PNG; - output_gamma = PNG_DEFAULT_sRGB; - } - - /* If 'do_local_background' is set check for the presence of gamma - * correction; this is part of the work-round for the libpng bug - * described above. - * - * TODO: fix libpng and remove this. - */ - if (do_local_background != 0) - { - png_fixed_point gtest; - - /* This is 'png_gamma_threshold' from pngrtran.c; the test used for - * gamma correction, the screen gamma hasn't been set on png_struct - * yet; it's set below. png_struct::gamma, however, is set to the - * final value. - */ - if (png_muldiv(>est, output_gamma, png_ptr->colorspace.gamma, - PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0) - do_local_background = 0; - - else if (mode == PNG_ALPHA_STANDARD) - { - do_local_background = 2/*required*/; - mode = PNG_ALPHA_PNG; /* prevent libpng doing it */ - } - - /* else leave as 1 for the checks below */ - } - - /* If the bit-depth changes then handle that here. */ - if ((change & PNG_FORMAT_FLAG_LINEAR) != 0) - { - if (linear != 0 /*16-bit output*/) - png_set_expand_16(png_ptr); - - else /* 8-bit output */ - png_set_scale_16(png_ptr); - - change &= ~PNG_FORMAT_FLAG_LINEAR; - } - - /* Now the background/alpha channel changes. */ - if ((change & PNG_FORMAT_FLAG_ALPHA) != 0) - { - /* Removing an alpha channel requires composition for the 8-bit - * formats; for the 16-bit it is already done, above, by the - * pre-multiplication and the channel just needs to be stripped. - */ - if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) - { - /* If RGB->gray is happening the alpha channel must be left and the - * operation completed locally. - * - * TODO: fix libpng and remove this. - */ - if (do_local_background != 0) - do_local_background = 2/*required*/; - - /* 16-bit output: just remove the channel */ - else if (linear != 0) /* compose on black (well, pre-multiply) */ - png_set_strip_alpha(png_ptr); - - /* 8-bit output: do an appropriate compose */ - else if (display->background != NULL) - { - png_color_16 c; - - c.index = 0; /*unused*/ - c.red = display->background->red; - c.green = display->background->green; - c.blue = display->background->blue; - c.gray = display->background->green; - - /* This is always an 8-bit sRGB value, using the 'green' channel - * for gray is much better than calculating the luminance here; - * we can get off-by-one errors in that calculation relative to - * the app expectations and that will show up in transparent - * pixels. - */ - png_set_background_fixed(png_ptr, &c, - PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, - 0/*gamma: not used*/); - } - - else /* compose on row: implemented below. */ - { - do_local_compose = 1; - /* This leaves the alpha channel in the output, so it has to be - * removed by the code below. Set the encoding to the 'OPTIMIZE' - * one so the code only has to hack on the pixels that require - * composition. - */ - mode = PNG_ALPHA_OPTIMIZED; - } - } - - else /* output needs an alpha channel */ - { - /* This is tricky because it happens before the swap operation has - * been accomplished; however, the swap does *not* swap the added - * alpha channel (weird API), so it must be added in the correct - * place. - */ - png_uint_32 filler; /* opaque filler */ - int where; - - if (linear != 0) - filler = 65535; - - else - filler = 255; - -#ifdef PNG_FORMAT_AFIRST_SUPPORTED - if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) - { - where = PNG_FILLER_BEFORE; - change &= ~PNG_FORMAT_FLAG_AFIRST; - } - - else -#endif - where = PNG_FILLER_AFTER; - - png_set_add_alpha(png_ptr, filler, where); - } - - /* This stops the (irrelevant) call to swap_alpha below. */ - change &= ~PNG_FORMAT_FLAG_ALPHA; - } - - /* Now set the alpha mode correctly; this is always done, even if there is - * no alpha channel in either the input or the output because it correctly - * sets the output gamma. - */ - png_set_alpha_mode_fixed(png_ptr, mode, output_gamma); - -# ifdef PNG_FORMAT_BGR_SUPPORTED - if ((change & PNG_FORMAT_FLAG_BGR) != 0) - { - /* Check only the output format; PNG is never BGR; don't do this if - * the output is gray, but fix up the 'format' value in that case. - */ - if ((format & PNG_FORMAT_FLAG_COLOR) != 0) - png_set_bgr(png_ptr); - - else - format &= ~PNG_FORMAT_FLAG_BGR; - - change &= ~PNG_FORMAT_FLAG_BGR; - } -# endif - -# ifdef PNG_FORMAT_AFIRST_SUPPORTED - if ((change & PNG_FORMAT_FLAG_AFIRST) != 0) - { - /* Only relevant if there is an alpha channel - it's particularly - * important to handle this correctly because do_local_compose may - * be set above and then libpng will keep the alpha channel for this - * code to remove. - */ - if ((format & PNG_FORMAT_FLAG_ALPHA) != 0) - { - /* Disable this if doing a local background, - * TODO: remove this when local background is no longer required. - */ - if (do_local_background != 2) - png_set_swap_alpha(png_ptr); - } - - else - format &= ~PNG_FORMAT_FLAG_AFIRST; - - change &= ~PNG_FORMAT_FLAG_AFIRST; - } -# endif - - /* If the *output* is 16-bit then we need to check for a byte-swap on this - * architecture. - */ - if (linear != 0) - { - PNG_CONST png_uint_16 le = 0x0001; - - if ((*(png_const_bytep) & le) != 0) - png_set_swap(png_ptr); - } - - /* If change is not now 0 some transformation is missing - error out. */ - if (change != 0) - png_error(png_ptr, "png_read_image: unsupported transformation"); - } - - PNG_SKIP_CHUNKS(png_ptr); - - /* Update the 'info' structure and make sure the result is as required; first - * make sure to turn on the interlace handling if it will be required - * (because it can't be turned on *after* the call to png_read_update_info!) - * - * TODO: remove the do_local_background fixup below. - */ - if (do_local_compose == 0 && do_local_background != 2) - passes = png_set_interlace_handling(png_ptr); - - png_read_update_info(png_ptr, info_ptr); - - { - png_uint_32 info_format = 0; - - if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) - info_format |= PNG_FORMAT_FLAG_COLOR; - - if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) - { - /* do_local_compose removes this channel below. */ - if (do_local_compose == 0) - { - /* do_local_background does the same if required. */ - if (do_local_background != 2 || - (format & PNG_FORMAT_FLAG_ALPHA) != 0) - info_format |= PNG_FORMAT_FLAG_ALPHA; - } - } - - else if (do_local_compose != 0) /* internal error */ - png_error(png_ptr, "png_image_read: alpha channel lost"); - - if (info_ptr->bit_depth == 16) - info_format |= PNG_FORMAT_FLAG_LINEAR; - -#ifdef PNG_FORMAT_BGR_SUPPORTED - if ((png_ptr->transformations & PNG_BGR) != 0) - info_format |= PNG_FORMAT_FLAG_BGR; -#endif - -#ifdef PNG_FORMAT_AFIRST_SUPPORTED - if (do_local_background == 2) - { - if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) - info_format |= PNG_FORMAT_FLAG_AFIRST; - } - - if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0 || - ((png_ptr->transformations & PNG_ADD_ALPHA) != 0 && - (png_ptr->flags & PNG_FLAG_FILLER_AFTER) == 0)) - { - if (do_local_background == 2) - png_error(png_ptr, "unexpected alpha swap transformation"); - - info_format |= PNG_FORMAT_FLAG_AFIRST; - } -# endif - - /* This is actually an internal error. */ - if (info_format != format) - png_error(png_ptr, "png_read_image: invalid transformations"); - } - - /* Now read the rows. If do_local_compose is set then it is necessary to use - * a local row buffer. The output will be GA, RGBA or BGRA and must be - * converted to G, RGB or BGR as appropriate. The 'local_row' member of the - * display acts as a flag. - */ - { - png_voidp first_row = display->buffer; - ptrdiff_t row_bytes = display->row_stride; - - if (linear != 0) - row_bytes *= 2; - - /* The following expression is designed to work correctly whether it gives - * a signed or an unsigned result. - */ - if (row_bytes < 0) - { - char *ptr = png_voidcast(char*, first_row); - ptr += (image->height-1) * (-row_bytes); - first_row = png_voidcast(png_voidp, ptr); - } - - display->first_row = first_row; - display->row_bytes = row_bytes; - } - - if (do_local_compose != 0) - { - int result; - png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); - - display->local_row = row; - result = png_safe_execute(image, png_image_read_composite, display); - display->local_row = NULL; - png_free(png_ptr, row); - - return result; - } - - else if (do_local_background == 2) - { - int result; - png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); - - display->local_row = row; - result = png_safe_execute(image, png_image_read_background, display); - display->local_row = NULL; - png_free(png_ptr, row); - - return result; - } - - else - { - png_alloc_size_t row_bytes = display->row_bytes; - - while (--passes >= 0) - { - png_uint_32 y = image->height; - png_bytep row = png_voidcast(png_bytep, display->first_row); - - while (y-- > 0) - { - png_read_row(png_ptr, row, NULL); - row += row_bytes; - } - } - - return 1; - } -} - -int PNGAPI -png_image_finish_read(png_imagep image, png_const_colorp background, - void *buffer, png_int_32 row_stride, void *colormap) -{ - if (image != NULL && image->version == PNG_IMAGE_VERSION) - { - /* Check for row_stride overflow. This check is not performed on the - * original PNG format because it may not occur in the output PNG format - * and libpng deals with the issues of reading the original. - */ - const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); - - if (image->width <= 0x7FFFFFFFU/channels) /* no overflow */ - { - png_uint_32 check; - const png_uint_32 png_row_stride = image->width * channels; - - if (row_stride == 0) - row_stride = (png_int_32)/*SAFE*/png_row_stride; - - if (row_stride < 0) - check = -row_stride; - - else - check = row_stride; - - if (image->opaque != NULL && buffer != NULL && check >= png_row_stride) - { - /* Now check for overflow of the image buffer calculation; this - * limits the whole image size to 32 bits for API compatibility with - * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. - */ - if (image->height <= 0xFFFFFFFF/png_row_stride) - { - if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 || - (image->colormap_entries > 0 && colormap != NULL)) - { - int result; - png_image_read_control display; - - memset(&display, 0, (sizeof display)); - display.image = image; - display.buffer = buffer; - display.row_stride = row_stride; - display.colormap = colormap; - display.background = background; - display.local_row = NULL; - - /* Choose the correct 'end' routine; for the color-map case - * all the setup has already been done. - */ - if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0) - result = png_safe_execute(image, - png_image_read_colormap, &display) && - png_safe_execute(image, - png_image_read_colormapped, &display); - - else - result = - png_safe_execute(image, - png_image_read_direct, &display); - - png_image_free(image); - return result; - } - - else - return png_image_error(image, - "png_image_finish_read[color-map]: no color-map"); - } - - else - return png_image_error(image, - "png_image_finish_read: image too large"); - } - - else - return png_image_error(image, - "png_image_finish_read: invalid argument"); - } - - else - return png_image_error(image, - "png_image_finish_read: row_stride too large"); - } - - else if (image != NULL) - return png_image_error(image, - "png_image_finish_read: damaged PNG_IMAGE_VERSION"); - - return 0; -} - -#endif /* SIMPLIFIED_READ */ -#endif /* READ */ diff --git a/third_party/libpng/pngrio.c b/third_party/libpng/pngrio.c deleted file mode 100644 index 5101d54a62..0000000000 --- a/third_party/libpng/pngrio.c +++ /dev/null @@ -1,120 +0,0 @@ - -/* pngrio.c - functions for data input - * - * Last changed in libpng 1.6.17 [March 26, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This file provides a location for all input. Users who need - * special handling are expected to write a function that has the same - * arguments as this and performs a similar function, but that possibly - * has a different input method. Note that you shouldn't change this - * function, but rather write a replacement function and then make - * libpng use it at run time with png_set_read_fn(...). - */ - -#include "pngpriv.h" - -#ifdef PNG_READ_SUPPORTED - -/* Read the data from whatever input you are using. The default routine - * reads from a file pointer. Note that this routine sometimes gets called - * with very small lengths, so you should implement some kind of simple - * buffering if you are using unbuffered reads. This should never be asked - * to read more than 64K on a 16-bit machine. - */ -void /* PRIVATE */ -png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length) -{ - png_debug1(4, "reading %d bytes", (int)length); - - if (png_ptr->read_data_fn != NULL) - (*(png_ptr->read_data_fn))(png_ptr, data, length); - - else - png_error(png_ptr, "Call to NULL read function"); -} - -#ifdef PNG_STDIO_SUPPORTED -/* This is the function that does the actual reading of data. If you are - * not reading from a standard C stream, you should create a replacement - * read_data function and use it at run time with png_set_read_fn(), rather - * than changing the library. - */ -void PNGCBAPI -png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) -{ - png_size_t check; - - if (png_ptr == NULL) - return; - - /* fread() returns 0 on error, so it is OK to store this in a png_size_t - * instead of an int, which is what fread() actually returns. - */ - check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr)); - - if (check != length) - png_error(png_ptr, "Read Error"); -} -#endif - -/* This function allows the application to supply a new input function - * for libpng if standard C streams aren't being used. - * - * This function takes as its arguments: - * - * png_ptr - pointer to a png input data structure - * - * io_ptr - pointer to user supplied structure containing info about - * the input functions. May be NULL. - * - * read_data_fn - pointer to a new input function that takes as its - * arguments a pointer to a png_struct, a pointer to - * a location where input data can be stored, and a 32-bit - * unsigned int that is the number of bytes to be read. - * To exit and output any fatal error messages the new write - * function should call png_error(png_ptr, "Error msg"). - * May be NULL, in which case libpng's default function will - * be used. - */ -void PNGAPI -png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr, - png_rw_ptr read_data_fn) -{ - if (png_ptr == NULL) - return; - - png_ptr->io_ptr = io_ptr; - -#ifdef PNG_STDIO_SUPPORTED - if (read_data_fn != NULL) - png_ptr->read_data_fn = read_data_fn; - - else - png_ptr->read_data_fn = png_default_read_data; -#else - png_ptr->read_data_fn = read_data_fn; -#endif - -#ifdef PNG_WRITE_SUPPORTED - /* It is an error to write to a read device */ - if (png_ptr->write_data_fn != NULL) - { - png_ptr->write_data_fn = NULL; - png_warning(png_ptr, - "Can't set both read_data_fn and write_data_fn in the" - " same structure"); - } -#endif - -#ifdef PNG_WRITE_FLUSH_SUPPORTED - png_ptr->output_flush_fn = NULL; -#endif -} -#endif /* READ */ diff --git a/third_party/libpng/pngrtran.c b/third_party/libpng/pngrtran.c deleted file mode 100644 index b65abbdefd..0000000000 --- a/third_party/libpng/pngrtran.c +++ /dev/null @@ -1,5000 +0,0 @@ - -/* pngrtran.c - transforms the data in a row for PNG readers - * - * Last changed in libpng 1.6.22 [(PENDING RELEASE)] - * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This file contains functions optionally called by an application - * in order to tell libpng how to handle data when reading a PNG. - * Transformations that are used in both reading and writing are - * in pngtrans.c. - */ - -#include "pngpriv.h" - -#ifdef PNG_READ_SUPPORTED - -/* Set the action on getting a CRC error for an ancillary or critical chunk. */ -void PNGAPI -png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action) -{ - png_debug(1, "in png_set_crc_action"); - - if (png_ptr == NULL) - return; - - /* Tell libpng how we react to CRC errors in critical chunks */ - switch (crit_action) - { - case PNG_CRC_NO_CHANGE: /* Leave setting as is */ - break; - - case PNG_CRC_WARN_USE: /* Warn/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; - break; - - case PNG_CRC_QUIET_USE: /* Quiet/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | - PNG_FLAG_CRC_CRITICAL_IGNORE; - break; - - case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ - png_warning(png_ptr, - "Can't discard critical data on CRC error"); - case PNG_CRC_ERROR_QUIT: /* Error/quit */ - - case PNG_CRC_DEFAULT: - default: - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - break; - } - - /* Tell libpng how we react to CRC errors in ancillary chunks */ - switch (ancil_action) - { - case PNG_CRC_NO_CHANGE: /* Leave setting as is */ - break; - - case PNG_CRC_WARN_USE: /* Warn/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; - break; - - case PNG_CRC_QUIET_USE: /* Quiet/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | - PNG_FLAG_CRC_ANCILLARY_NOWARN; - break; - - case PNG_CRC_ERROR_QUIT: /* Error/quit */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; - break; - - case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ - - case PNG_CRC_DEFAULT: - default: - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - break; - } -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -/* Is it OK to set a transformation now? Only if png_start_read_image or - * png_read_update_info have not been called. It is not necessary for the IHDR - * to have been read in all cases; the need_IHDR parameter allows for this - * check too. - */ -static int -png_rtran_ok(png_structrp png_ptr, int need_IHDR) -{ - if (png_ptr != NULL) - { - if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0) - png_app_error(png_ptr, - "invalid after png_start_read_image or png_read_update_info"); - - else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_app_error(png_ptr, "invalid before the PNG header has been read"); - - else - { - /* Turn on failure to initialize correctly for all transforms. */ - png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; - - return 1; /* Ok */ - } - } - - return 0; /* no png_error possible! */ -} -#endif - -#ifdef PNG_READ_BACKGROUND_SUPPORTED -/* Handle alpha and tRNS via a background color */ -void PNGFAPI -png_set_background_fixed(png_structrp png_ptr, - png_const_color_16p background_color, int background_gamma_code, - int need_expand, png_fixed_point background_gamma) -{ - png_debug(1, "in png_set_background_fixed"); - - if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL) - return; - - if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) - { - png_warning(png_ptr, "Application must supply a known background gamma"); - return; - } - - png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA; - png_ptr->transformations &= ~PNG_ENCODE_ALPHA; - png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; - - png_ptr->background = *background_color; - png_ptr->background_gamma = background_gamma; - png_ptr->background_gamma_type = (png_byte)(background_gamma_code); - if (need_expand != 0) - png_ptr->transformations |= PNG_BACKGROUND_EXPAND; - else - png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; -} - -# ifdef PNG_FLOATING_POINT_SUPPORTED -void PNGAPI -png_set_background(png_structrp png_ptr, - png_const_color_16p background_color, int background_gamma_code, - int need_expand, double background_gamma) -{ - png_set_background_fixed(png_ptr, background_color, background_gamma_code, - need_expand, png_fixed(png_ptr, background_gamma, "png_set_background")); -} -# endif /* FLOATING_POINT */ -#endif /* READ_BACKGROUND */ - -/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the - * one that pngrtran does first (scale) happens. This is necessary to allow the - * TRANSFORM and API behavior to be somewhat consistent, and it's simpler. - */ -#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED -void PNGAPI -png_set_scale_16(png_structrp png_ptr) -{ - png_debug(1, "in png_set_scale_16"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= PNG_SCALE_16_TO_8; -} -#endif - -#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED -/* Chop 16-bit depth files to 8-bit depth */ -void PNGAPI -png_set_strip_16(png_structrp png_ptr) -{ - png_debug(1, "in png_set_strip_16"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= PNG_16_TO_8; -} -#endif - -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED -void PNGAPI -png_set_strip_alpha(png_structrp png_ptr) -{ - png_debug(1, "in png_set_strip_alpha"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= PNG_STRIP_ALPHA; -} -#endif - -#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED) -static png_fixed_point -translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma, - int is_screen) -{ - /* Check for flag values. The main reason for having the old Mac value as a - * flag is that it is pretty near impossible to work out what the correct - * value is from Apple documentation - a working Mac system is needed to - * discover the value! - */ - if (output_gamma == PNG_DEFAULT_sRGB || - output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB) - { - /* If there is no sRGB support this just sets the gamma to the standard - * sRGB value. (This is a side effect of using this function!) - */ -# ifdef PNG_READ_sRGB_SUPPORTED - png_ptr->flags |= PNG_FLAG_ASSUME_sRGB; -# else - PNG_UNUSED(png_ptr) -# endif - if (is_screen != 0) - output_gamma = PNG_GAMMA_sRGB; - else - output_gamma = PNG_GAMMA_sRGB_INVERSE; - } - - else if (output_gamma == PNG_GAMMA_MAC_18 || - output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18) - { - if (is_screen != 0) - output_gamma = PNG_GAMMA_MAC_OLD; - else - output_gamma = PNG_GAMMA_MAC_INVERSE; - } - - return output_gamma; -} - -# ifdef PNG_FLOATING_POINT_SUPPORTED -static png_fixed_point -convert_gamma_value(png_structrp png_ptr, double output_gamma) -{ - /* The following silently ignores cases where fixed point (times 100,000) - * gamma values are passed to the floating point API. This is safe and it - * means the fixed point constants work just fine with the floating point - * API. The alternative would just lead to undetected errors and spurious - * bug reports. Negative values fail inside the _fixed API unless they - * correspond to the flag values. - */ - if (output_gamma > 0 && output_gamma < 128) - output_gamma *= PNG_FP_1; - - /* This preserves -1 and -2 exactly: */ - output_gamma = floor(output_gamma + .5); - - if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN) - png_fixed_error(png_ptr, "gamma value"); - - return (png_fixed_point)output_gamma; -} -# endif -#endif /* READ_ALPHA_MODE || READ_GAMMA */ - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED -void PNGFAPI -png_set_alpha_mode_fixed(png_structrp png_ptr, int mode, - png_fixed_point output_gamma) -{ - int compose = 0; - png_fixed_point file_gamma; - - png_debug(1, "in png_set_alpha_mode"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/); - - /* Validate the value to ensure it is in a reasonable range. The value - * is expected to be 1 or greater, but this range test allows for some - * viewing correction values. The intent is to weed out users of this API - * who use the inverse of the gamma value accidentally! Since some of these - * values are reasonable this may have to be changed: - * - * 1.6.x: changed from 0.07..3 to 0.01..100 (to accomodate the optimal 16-bit - * gamma of 36, and its reciprocal.) - */ - if (output_gamma < 1000 || output_gamma > 10000000) - png_error(png_ptr, "output gamma out of expected range"); - - /* The default file gamma is the inverse of the output gamma; the output - * gamma may be changed below so get the file value first: - */ - file_gamma = png_reciprocal(output_gamma); - - /* There are really 8 possibilities here, composed of any combination - * of: - * - * premultiply the color channels - * do not encode non-opaque pixels - * encode the alpha as well as the color channels - * - * The differences disappear if the input/output ('screen') gamma is 1.0, - * because then the encoding is a no-op and there is only the choice of - * premultiplying the color channels or not. - * - * png_set_alpha_mode and png_set_background interact because both use - * png_compose to do the work. Calling both is only useful when - * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along - * with a default gamma value. Otherwise PNG_COMPOSE must not be set. - */ - switch (mode) - { - case PNG_ALPHA_PNG: /* default: png standard */ - /* No compose, but it may be set by png_set_background! */ - png_ptr->transformations &= ~PNG_ENCODE_ALPHA; - png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; - break; - - case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */ - compose = 1; - png_ptr->transformations &= ~PNG_ENCODE_ALPHA; - png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; - /* The output is linear: */ - output_gamma = PNG_FP_1; - break; - - case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */ - compose = 1; - png_ptr->transformations &= ~PNG_ENCODE_ALPHA; - png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA; - /* output_gamma records the encoding of opaque pixels! */ - break; - - case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */ - compose = 1; - png_ptr->transformations |= PNG_ENCODE_ALPHA; - png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; - break; - - default: - png_error(png_ptr, "invalid alpha mode"); - } - - /* Only set the default gamma if the file gamma has not been set (this has - * the side effect that the gamma in a second call to png_set_alpha_mode will - * be ignored.) - */ - if (png_ptr->colorspace.gamma == 0) - { - png_ptr->colorspace.gamma = file_gamma; - png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; - } - - /* But always set the output gamma: */ - png_ptr->screen_gamma = output_gamma; - - /* Finally, if pre-multiplying, set the background fields to achieve the - * desired result. - */ - if (compose != 0) - { - /* And obtain alpha pre-multiplication by composing on black: */ - memset(&png_ptr->background, 0, (sizeof png_ptr->background)); - png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */ - png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE; - png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; - - if ((png_ptr->transformations & PNG_COMPOSE) != 0) - png_error(png_ptr, - "conflicting calls to set alpha mode and background"); - - png_ptr->transformations |= PNG_COMPOSE; - } -} - -# ifdef PNG_FLOATING_POINT_SUPPORTED -void PNGAPI -png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma) -{ - png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr, - output_gamma)); -} -# endif -#endif - -#ifdef PNG_READ_QUANTIZE_SUPPORTED -/* Dither file to 8-bit. Supply a palette, the current number - * of elements in the palette, the maximum number of elements - * allowed, and a histogram if possible. If the current number - * of colors is greater than the maximum number, the palette will be - * modified to fit in the maximum number. "full_quantize" indicates - * whether we need a quantizing cube set up for RGB images, or if we - * simply are reducing the number of colors in a paletted image. - */ - -typedef struct png_dsort_struct -{ - struct png_dsort_struct * next; - png_byte left; - png_byte right; -} png_dsort; -typedef png_dsort * png_dsortp; -typedef png_dsort * * png_dsortpp; - -void PNGAPI -png_set_quantize(png_structrp png_ptr, png_colorp palette, - int num_palette, int maximum_colors, png_const_uint_16p histogram, - int full_quantize) -{ - png_debug(1, "in png_set_quantize"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= PNG_QUANTIZE; - - if (full_quantize == 0) - { - int i; - - png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr, - (png_uint_32)(num_palette * (sizeof (png_byte)))); - for (i = 0; i < num_palette; i++) - png_ptr->quantize_index[i] = (png_byte)i; - } - - if (num_palette > maximum_colors) - { - if (histogram != NULL) - { - /* This is easy enough, just throw out the least used colors. - * Perhaps not the best solution, but good enough. - */ - - int i; - - /* Initialize an array to sort colors */ - png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr, - (png_uint_32)(num_palette * (sizeof (png_byte)))); - - /* Initialize the quantize_sort array */ - for (i = 0; i < num_palette; i++) - png_ptr->quantize_sort[i] = (png_byte)i; - - /* Find the least used palette entries by starting a - * bubble sort, and running it until we have sorted - * out enough colors. Note that we don't care about - * sorting all the colors, just finding which are - * least used. - */ - - for (i = num_palette - 1; i >= maximum_colors; i--) - { - int done; /* To stop early if the list is pre-sorted */ - int j; - - done = 1; - for (j = 0; j < i; j++) - { - if (histogram[png_ptr->quantize_sort[j]] - < histogram[png_ptr->quantize_sort[j + 1]]) - { - png_byte t; - - t = png_ptr->quantize_sort[j]; - png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1]; - png_ptr->quantize_sort[j + 1] = t; - done = 0; - } - } - - if (done != 0) - break; - } - - /* Swap the palette around, and set up a table, if necessary */ - if (full_quantize != 0) - { - int j = num_palette; - - /* Put all the useful colors within the max, but don't - * move the others. - */ - for (i = 0; i < maximum_colors; i++) - { - if ((int)png_ptr->quantize_sort[i] >= maximum_colors) - { - do - j--; - while ((int)png_ptr->quantize_sort[j] >= maximum_colors); - - palette[i] = palette[j]; - } - } - } - else - { - int j = num_palette; - - /* Move all the used colors inside the max limit, and - * develop a translation table. - */ - for (i = 0; i < maximum_colors; i++) - { - /* Only move the colors we need to */ - if ((int)png_ptr->quantize_sort[i] >= maximum_colors) - { - png_color tmp_color; - - do - j--; - while ((int)png_ptr->quantize_sort[j] >= maximum_colors); - - tmp_color = palette[j]; - palette[j] = palette[i]; - palette[i] = tmp_color; - /* Indicate where the color went */ - png_ptr->quantize_index[j] = (png_byte)i; - png_ptr->quantize_index[i] = (png_byte)j; - } - } - - /* Find closest color for those colors we are not using */ - for (i = 0; i < num_palette; i++) - { - if ((int)png_ptr->quantize_index[i] >= maximum_colors) - { - int min_d, k, min_k, d_index; - - /* Find the closest color to one we threw out */ - d_index = png_ptr->quantize_index[i]; - min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); - for (k = 1, min_k = 0; k < maximum_colors; k++) - { - int d; - - d = PNG_COLOR_DIST(palette[d_index], palette[k]); - - if (d < min_d) - { - min_d = d; - min_k = k; - } - } - /* Point to closest color */ - png_ptr->quantize_index[i] = (png_byte)min_k; - } - } - } - png_free(png_ptr, png_ptr->quantize_sort); - png_ptr->quantize_sort = NULL; - } - else - { - /* This is much harder to do simply (and quickly). Perhaps - * we need to go through a median cut routine, but those - * don't always behave themselves with only a few colors - * as input. So we will just find the closest two colors, - * and throw out one of them (chosen somewhat randomly). - * [We don't understand this at all, so if someone wants to - * work on improving it, be our guest - AED, GRP] - */ - int i; - int max_d; - int num_new_palette; - png_dsortp t; - png_dsortpp hash; - - t = NULL; - - /* Initialize palette index arrays */ - png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, - (png_uint_32)(num_palette * (sizeof (png_byte)))); - png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, - (png_uint_32)(num_palette * (sizeof (png_byte)))); - - /* Initialize the sort array */ - for (i = 0; i < num_palette; i++) - { - png_ptr->index_to_palette[i] = (png_byte)i; - png_ptr->palette_to_index[i] = (png_byte)i; - } - - hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 * - (sizeof (png_dsortp)))); - - num_new_palette = num_palette; - - /* Initial wild guess at how far apart the farthest pixel - * pair we will be eliminating will be. Larger - * numbers mean more areas will be allocated, Smaller - * numbers run the risk of not saving enough data, and - * having to do this all over again. - * - * I have not done extensive checking on this number. - */ - max_d = 96; - - while (num_new_palette > maximum_colors) - { - for (i = 0; i < num_new_palette - 1; i++) - { - int j; - - for (j = i + 1; j < num_new_palette; j++) - { - int d; - - d = PNG_COLOR_DIST(palette[i], palette[j]); - - if (d <= max_d) - { - - t = (png_dsortp)png_malloc_warn(png_ptr, - (png_uint_32)(sizeof (png_dsort))); - - if (t == NULL) - break; - - t->next = hash[d]; - t->left = (png_byte)i; - t->right = (png_byte)j; - hash[d] = t; - } - } - if (t == NULL) - break; - } - - if (t != NULL) - for (i = 0; i <= max_d; i++) - { - if (hash[i] != NULL) - { - png_dsortp p; - - for (p = hash[i]; p; p = p->next) - { - if ((int)png_ptr->index_to_palette[p->left] - < num_new_palette && - (int)png_ptr->index_to_palette[p->right] - < num_new_palette) - { - int j, next_j; - - if (num_new_palette & 0x01) - { - j = p->left; - next_j = p->right; - } - else - { - j = p->right; - next_j = p->left; - } - - num_new_palette--; - palette[png_ptr->index_to_palette[j]] - = palette[num_new_palette]; - if (full_quantize == 0) - { - int k; - - for (k = 0; k < num_palette; k++) - { - if (png_ptr->quantize_index[k] == - png_ptr->index_to_palette[j]) - png_ptr->quantize_index[k] = - png_ptr->index_to_palette[next_j]; - - if ((int)png_ptr->quantize_index[k] == - num_new_palette) - png_ptr->quantize_index[k] = - png_ptr->index_to_palette[j]; - } - } - - png_ptr->index_to_palette[png_ptr->palette_to_index - [num_new_palette]] = png_ptr->index_to_palette[j]; - - png_ptr->palette_to_index[png_ptr->index_to_palette[j]] - = png_ptr->palette_to_index[num_new_palette]; - - png_ptr->index_to_palette[j] = - (png_byte)num_new_palette; - - png_ptr->palette_to_index[num_new_palette] = - (png_byte)j; - } - if (num_new_palette <= maximum_colors) - break; - } - if (num_new_palette <= maximum_colors) - break; - } - } - - for (i = 0; i < 769; i++) - { - if (hash[i] != NULL) - { - png_dsortp p = hash[i]; - while (p) - { - t = p->next; - png_free(png_ptr, p); - p = t; - } - } - hash[i] = 0; - } - max_d += 96; - } - png_free(png_ptr, hash); - png_free(png_ptr, png_ptr->palette_to_index); - png_free(png_ptr, png_ptr->index_to_palette); - png_ptr->palette_to_index = NULL; - png_ptr->index_to_palette = NULL; - } - num_palette = maximum_colors; - } - if (png_ptr->palette == NULL) - { - png_ptr->palette = palette; - } - png_ptr->num_palette = (png_uint_16)num_palette; - - if (full_quantize != 0) - { - int i; - png_bytep distance; - int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS + - PNG_QUANTIZE_BLUE_BITS; - int num_red = (1 << PNG_QUANTIZE_RED_BITS); - int num_green = (1 << PNG_QUANTIZE_GREEN_BITS); - int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS); - png_size_t num_entries = ((png_size_t)1 << total_bits); - - png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr, - (png_uint_32)(num_entries * (sizeof (png_byte)))); - - distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * - (sizeof (png_byte)))); - - memset(distance, 0xff, num_entries * (sizeof (png_byte))); - - for (i = 0; i < num_palette; i++) - { - int ir, ig, ib; - int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS)); - int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS)); - int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS)); - - for (ir = 0; ir < num_red; ir++) - { - /* int dr = abs(ir - r); */ - int dr = ((ir > r) ? ir - r : r - ir); - int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS + - PNG_QUANTIZE_GREEN_BITS)); - - for (ig = 0; ig < num_green; ig++) - { - /* int dg = abs(ig - g); */ - int dg = ((ig > g) ? ig - g : g - ig); - int dt = dr + dg; - int dm = ((dr > dg) ? dr : dg); - int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS); - - for (ib = 0; ib < num_blue; ib++) - { - int d_index = index_g | ib; - /* int db = abs(ib - b); */ - int db = ((ib > b) ? ib - b : b - ib); - int dmax = ((dm > db) ? dm : db); - int d = dmax + dt + db; - - if (d < (int)distance[d_index]) - { - distance[d_index] = (png_byte)d; - png_ptr->palette_lookup[d_index] = (png_byte)i; - } - } - } - } - } - - png_free(png_ptr, distance); - } -} -#endif /* READ_QUANTIZE */ - -#ifdef PNG_READ_GAMMA_SUPPORTED -void PNGFAPI -png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma, - png_fixed_point file_gamma) -{ - png_debug(1, "in png_set_gamma_fixed"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - /* New in libpng-1.5.4 - reserve particular negative values as flags. */ - scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/); - file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/); - - /* Checking the gamma values for being >0 was added in 1.5.4 along with the - * premultiplied alpha support; this actually hides an undocumented feature - * of the previous implementation which allowed gamma processing to be - * disabled in background handling. There is no evidence (so far) that this - * was being used; however, png_set_background itself accepted and must still - * accept '0' for the gamma value it takes, because it isn't always used. - * - * Since this is an API change (albeit a very minor one that removes an - * undocumented API feature) the following checks were only enabled in - * libpng-1.6.0. - */ - if (file_gamma <= 0) - png_error(png_ptr, "invalid file gamma in png_set_gamma"); - - if (scrn_gamma <= 0) - png_error(png_ptr, "invalid screen gamma in png_set_gamma"); - - /* Set the gamma values unconditionally - this overrides the value in the PNG - * file if a gAMA chunk was present. png_set_alpha_mode provides a - * different, easier, way to default the file gamma. - */ - png_ptr->colorspace.gamma = file_gamma; - png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; - png_ptr->screen_gamma = scrn_gamma; -} - -# ifdef PNG_FLOATING_POINT_SUPPORTED -void PNGAPI -png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma) -{ - png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma), - convert_gamma_value(png_ptr, file_gamma)); -} -# endif /* FLOATING_POINT */ -#endif /* READ_GAMMA */ - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* Expand paletted images to RGB, expand grayscale images of - * less than 8-bit depth to 8-bit depth, and expand tRNS chunks - * to alpha channels. - */ -void PNGAPI -png_set_expand(png_structrp png_ptr) -{ - png_debug(1, "in png_set_expand"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); -} - -/* GRR 19990627: the following three functions currently are identical - * to png_set_expand(). However, it is entirely reasonable that someone - * might wish to expand an indexed image to RGB but *not* expand a single, - * fully transparent palette entry to a full alpha channel--perhaps instead - * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace - * the transparent color with a particular RGB value, or drop tRNS entirely. - * IOW, a future version of the library may make the transformations flag - * a bit more fine-grained, with separate bits for each of these three - * functions. - * - * More to the point, these functions make it obvious what libpng will be - * doing, whereas "expand" can (and does) mean any number of things. - * - * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified - * to expand only the sample depth but not to expand the tRNS to alpha - * and its name was changed to png_set_expand_gray_1_2_4_to_8(). - */ - -/* Expand paletted images to RGB. */ -void PNGAPI -png_set_palette_to_rgb(png_structrp png_ptr) -{ - png_debug(1, "in png_set_palette_to_rgb"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); -} - -/* Expand grayscale images of less than 8-bit depth to 8 bits. */ -void PNGAPI -png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr) -{ - png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= PNG_EXPAND; -} - -/* Expand tRNS chunks to alpha channels. */ -void PNGAPI -png_set_tRNS_to_alpha(png_structrp png_ptr) -{ - png_debug(1, "in png_set_tRNS_to_alpha"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); -} -#endif /* READ_EXPAND */ - -#ifdef PNG_READ_EXPAND_16_SUPPORTED -/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise - * it may not work correctly.) - */ -void PNGAPI -png_set_expand_16(png_structrp png_ptr) -{ - png_debug(1, "in png_set_expand_16"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS); -} -#endif - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED -void PNGAPI -png_set_gray_to_rgb(png_structrp png_ptr) -{ - png_debug(1, "in png_set_gray_to_rgb"); - - if (png_rtran_ok(png_ptr, 0) == 0) - return; - - /* Because rgb must be 8 bits or more: */ - png_set_expand_gray_1_2_4_to_8(png_ptr); - png_ptr->transformations |= PNG_GRAY_TO_RGB; -} -#endif - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -void PNGFAPI -png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action, - png_fixed_point red, png_fixed_point green) -{ - png_debug(1, "in png_set_rgb_to_gray"); - - /* Need the IHDR here because of the check on color_type below. */ - /* TODO: fix this */ - if (png_rtran_ok(png_ptr, 1) == 0) - return; - - switch (error_action) - { - case PNG_ERROR_ACTION_NONE: - png_ptr->transformations |= PNG_RGB_TO_GRAY; - break; - - case PNG_ERROR_ACTION_WARN: - png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; - break; - - case PNG_ERROR_ACTION_ERROR: - png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; - break; - - default: - png_error(png_ptr, "invalid error action to rgb_to_gray"); - } - - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) -#ifdef PNG_READ_EXPAND_SUPPORTED - png_ptr->transformations |= PNG_EXPAND; -#else - { - /* Make this an error in 1.6 because otherwise the application may assume - * that it just worked and get a memory overwrite. - */ - png_error(png_ptr, - "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED"); - - /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */ - } -#endif - { - if (red >= 0 && green >= 0 && red + green <= PNG_FP_1) - { - png_uint_16 red_int, green_int; - - /* NOTE: this calculation does not round, but this behavior is retained - * for consistency; the inaccuracy is very small. The code here always - * overwrites the coefficients, regardless of whether they have been - * defaulted or set already. - */ - red_int = (png_uint_16)(((png_uint_32)red*32768)/100000); - green_int = (png_uint_16)(((png_uint_32)green*32768)/100000); - - png_ptr->rgb_to_gray_red_coeff = red_int; - png_ptr->rgb_to_gray_green_coeff = green_int; - png_ptr->rgb_to_gray_coefficients_set = 1; - } - - else - { - if (red >= 0 && green >= 0) - png_app_warning(png_ptr, - "ignoring out of range rgb_to_gray coefficients"); - - /* Use the defaults, from the cHRM chunk if set, else the historical - * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See - * png_do_rgb_to_gray for more discussion of the values. In this case - * the coefficients are not marked as 'set' and are not overwritten if - * something has already provided a default. - */ - if (png_ptr->rgb_to_gray_red_coeff == 0 && - png_ptr->rgb_to_gray_green_coeff == 0) - { - png_ptr->rgb_to_gray_red_coeff = 6968; - png_ptr->rgb_to_gray_green_coeff = 23434; - /* png_ptr->rgb_to_gray_blue_coeff = 2366; */ - } - } - } -} - -#ifdef PNG_FLOATING_POINT_SUPPORTED -/* Convert a RGB image to a grayscale of the same width. This allows us, - * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. - */ - -void PNGAPI -png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red, - double green) -{ - png_set_rgb_to_gray_fixed(png_ptr, error_action, - png_fixed(png_ptr, red, "rgb to gray red coefficient"), - png_fixed(png_ptr, green, "rgb to gray green coefficient")); -} -#endif /* FLOATING POINT */ - -#endif /* RGB_TO_GRAY */ - -#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ - defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) -void PNGAPI -png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr - read_user_transform_fn) -{ - png_debug(1, "in png_set_read_user_transform_fn"); - -#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED - png_ptr->transformations |= PNG_USER_TRANSFORM; - png_ptr->read_user_transform_fn = read_user_transform_fn; -#endif -} -#endif - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -#ifdef PNG_READ_GAMMA_SUPPORTED -/* In the case of gamma transformations only do transformations on images where - * the [file] gamma and screen_gamma are not close reciprocals, otherwise it - * slows things down slightly, and also needlessly introduces small errors. - */ -static int /* PRIVATE */ -png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma) -{ - /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma - * correction as a difference of the overall transform from 1.0 - * - * We want to compare the threshold with s*f - 1, if we get - * overflow here it is because of wacky gamma values so we - * turn on processing anyway. - */ - png_fixed_point gtest; - return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) || - png_gamma_significant(gtest); -} -#endif - -/* Initialize everything needed for the read. This includes modifying - * the palette. - */ - -/* For the moment 'png_init_palette_transformations' and - * 'png_init_rgb_transformations' only do some flag canceling optimizations. - * The intent is that these two routines should have palette or rgb operations - * extracted from 'png_init_read_transformations'. - */ -static void /* PRIVATE */ -png_init_palette_transformations(png_structrp png_ptr) -{ - /* Called to handle the (input) palette case. In png_do_read_transformations - * the first step is to expand the palette if requested, so this code must - * take care to only make changes that are invariant with respect to the - * palette expansion, or only do them if there is no expansion. - * - * STRIP_ALPHA has already been handled in the caller (by setting num_trans - * to 0.) - */ - int input_has_alpha = 0; - int input_has_transparency = 0; - - if (png_ptr->num_trans > 0) - { - int i; - - /* Ignore if all the entries are opaque (unlikely!) */ - for (i=0; i<png_ptr->num_trans; ++i) - { - if (png_ptr->trans_alpha[i] == 255) - continue; - else if (png_ptr->trans_alpha[i] == 0) - input_has_transparency = 1; - else - { - input_has_transparency = 1; - input_has_alpha = 1; - break; - } - } - } - - /* If no alpha we can optimize. */ - if (input_has_alpha == 0) - { - /* Any alpha means background and associative alpha processing is - * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA - * and ENCODE_ALPHA are irrelevant. - */ - png_ptr->transformations &= ~PNG_ENCODE_ALPHA; - png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; - - if (input_has_transparency == 0) - png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); - } - -#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) - /* png_set_background handling - deals with the complexity of whether the - * background color is in the file format or the screen format in the case - * where an 'expand' will happen. - */ - - /* The following code cannot be entered in the alpha pre-multiplication case - * because PNG_BACKGROUND_EXPAND is cancelled below. - */ - if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 && - (png_ptr->transformations & PNG_EXPAND) != 0) - { - { - png_ptr->background.red = - png_ptr->palette[png_ptr->background.index].red; - png_ptr->background.green = - png_ptr->palette[png_ptr->background.index].green; - png_ptr->background.blue = - png_ptr->palette[png_ptr->background.index].blue; - -#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) - { - if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0) - { - /* Invert the alpha channel (in tRNS) unless the pixels are - * going to be expanded, in which case leave it for later - */ - int i, istop = png_ptr->num_trans; - - for (i=0; i<istop; i++) - png_ptr->trans_alpha[i] = (png_byte)(255 - - png_ptr->trans_alpha[i]); - } - } -#endif /* READ_INVERT_ALPHA */ - } - } /* background expand and (therefore) no alpha association. */ -#endif /* READ_EXPAND && READ_BACKGROUND */ -} - -static void /* PRIVATE */ -png_init_rgb_transformations(png_structrp png_ptr) -{ - /* Added to libpng-1.5.4: check the color type to determine whether there - * is any alpha or transparency in the image and simply cancel the - * background and alpha mode stuff if there isn't. - */ - int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0; - int input_has_transparency = png_ptr->num_trans > 0; - - /* If no alpha we can optimize. */ - if (input_has_alpha == 0) - { - /* Any alpha means background and associative alpha processing is - * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA - * and ENCODE_ALPHA are irrelevant. - */ -# ifdef PNG_READ_ALPHA_MODE_SUPPORTED - png_ptr->transformations &= ~PNG_ENCODE_ALPHA; - png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; -# endif - - if (input_has_transparency == 0) - png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); - } - -#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) - /* png_set_background handling - deals with the complexity of whether the - * background color is in the file format or the screen format in the case - * where an 'expand' will happen. - */ - - /* The following code cannot be entered in the alpha pre-multiplication case - * because PNG_BACKGROUND_EXPAND is cancelled below. - */ - if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 && - (png_ptr->transformations & PNG_EXPAND) != 0 && - (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) - /* i.e., GRAY or GRAY_ALPHA */ - { - { - /* Expand background and tRNS chunks */ - int gray = png_ptr->background.gray; - int trans_gray = png_ptr->trans_color.gray; - - switch (png_ptr->bit_depth) - { - case 1: - gray *= 0xff; - trans_gray *= 0xff; - break; - - case 2: - gray *= 0x55; - trans_gray *= 0x55; - break; - - case 4: - gray *= 0x11; - trans_gray *= 0x11; - break; - - default: - - case 8: - /* FALL THROUGH (Already 8 bits) */ - - case 16: - /* Already a full 16 bits */ - break; - } - - png_ptr->background.red = png_ptr->background.green = - png_ptr->background.blue = (png_uint_16)gray; - - if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0) - { - png_ptr->trans_color.red = png_ptr->trans_color.green = - png_ptr->trans_color.blue = (png_uint_16)trans_gray; - } - } - } /* background expand and (therefore) no alpha association. */ -#endif /* READ_EXPAND && READ_BACKGROUND */ -} - -void /* PRIVATE */ -png_init_read_transformations(png_structrp png_ptr) -{ - png_debug(1, "in png_init_read_transformations"); - - /* This internal function is called from png_read_start_row in pngrutil.c - * and it is called before the 'rowbytes' calculation is done, so the code - * in here can change or update the transformations flags. - * - * First do updates that do not depend on the details of the PNG image data - * being processed. - */ - -#ifdef PNG_READ_GAMMA_SUPPORTED - /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds - * png_set_alpha_mode and this is another source for a default file gamma so - * the test needs to be performed later - here. In addition prior to 1.5.4 - * the tests were repeated for the PALETTE color type here - this is no - * longer necessary (and doesn't seem to have been necessary before.) - */ - { - /* The following temporary indicates if overall gamma correction is - * required. - */ - int gamma_correction = 0; - - if (png_ptr->colorspace.gamma != 0) /* has been set */ - { - if (png_ptr->screen_gamma != 0) /* screen set too */ - gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma, - png_ptr->screen_gamma); - - else - /* Assume the output matches the input; a long time default behavior - * of libpng, although the standard has nothing to say about this. - */ - png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma); - } - - else if (png_ptr->screen_gamma != 0) - /* The converse - assume the file matches the screen, note that this - * perhaps undesireable default can (from 1.5.4) be changed by calling - * png_set_alpha_mode (even if the alpha handling mode isn't required - * or isn't changed from the default.) - */ - png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma); - - else /* neither are set */ - /* Just in case the following prevents any processing - file and screen - * are both assumed to be linear and there is no way to introduce a - * third gamma value other than png_set_background with 'UNIQUE', and, - * prior to 1.5.4 - */ - png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1; - - /* We have a gamma value now. */ - png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; - - /* Now turn the gamma transformation on or off as appropriate. Notice - * that PNG_GAMMA just refers to the file->screen correction. Alpha - * composition may independently cause gamma correction because it needs - * linear data (e.g. if the file has a gAMA chunk but the screen gamma - * hasn't been specified.) In any case this flag may get turned off in - * the code immediately below if the transform can be handled outside the - * row loop. - */ - if (gamma_correction != 0) - png_ptr->transformations |= PNG_GAMMA; - - else - png_ptr->transformations &= ~PNG_GAMMA; - } -#endif - - /* Certain transformations have the effect of preventing other - * transformations that happen afterward in png_do_read_transformations; - * resolve the interdependencies here. From the code of - * png_do_read_transformations the order is: - * - * 1) PNG_EXPAND (including PNG_EXPAND_tRNS) - * 2) PNG_STRIP_ALPHA (if no compose) - * 3) PNG_RGB_TO_GRAY - * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY - * 5) PNG_COMPOSE - * 6) PNG_GAMMA - * 7) PNG_STRIP_ALPHA (if compose) - * 8) PNG_ENCODE_ALPHA - * 9) PNG_SCALE_16_TO_8 - * 10) PNG_16_TO_8 - * 11) PNG_QUANTIZE (converts to palette) - * 12) PNG_EXPAND_16 - * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY - * 14) PNG_INVERT_MONO - * 15) PNG_INVERT_ALPHA - * 16) PNG_SHIFT - * 17) PNG_PACK - * 18) PNG_BGR - * 19) PNG_PACKSWAP - * 20) PNG_FILLER (includes PNG_ADD_ALPHA) - * 21) PNG_SWAP_ALPHA - * 22) PNG_SWAP_BYTES - * 23) PNG_USER_TRANSFORM [must be last] - */ -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && - (png_ptr->transformations & PNG_COMPOSE) == 0) - { - /* Stripping the alpha channel happens immediately after the 'expand' - * transformations, before all other transformation, so it cancels out - * the alpha handling. It has the side effect negating the effect of - * PNG_EXPAND_tRNS too: - */ - png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA | - PNG_EXPAND_tRNS); - png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; - - /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen - * so transparency information would remain just so long as it wasn't - * expanded. This produces unexpected API changes if the set of things - * that do PNG_EXPAND_tRNS changes (perfectly possible given the - * documentation - which says ask for what you want, accept what you - * get.) This makes the behavior consistent from 1.5.4: - */ - png_ptr->num_trans = 0; - } -#endif /* STRIP_ALPHA supported, no COMPOSE */ - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA - * settings will have no effect. - */ - if (png_gamma_significant(png_ptr->screen_gamma) == 0) - { - png_ptr->transformations &= ~PNG_ENCODE_ALPHA; - png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; - } -#endif - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED - /* Make sure the coefficients for the rgb to gray conversion are set - * appropriately. - */ - if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) - png_colorspace_set_rgb_coefficients(png_ptr); -#endif - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED -#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) - /* Detect gray background and attempt to enable optimization for - * gray --> RGB case. - * - * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or - * RGB_ALPHA (in which case need_expand is superfluous anyway), the - * background color might actually be gray yet not be flagged as such. - * This is not a problem for the current code, which uses - * PNG_BACKGROUND_IS_GRAY only to decide when to do the - * png_do_gray_to_rgb() transformation. - * - * TODO: this code needs to be revised to avoid the complexity and - * interdependencies. The color type of the background should be recorded in - * png_set_background, along with the bit depth, then the code has a record - * of exactly what color space the background is currently in. - */ - if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0) - { - /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if - * the file was grayscale the background value is gray. - */ - if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) - png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; - } - - else if ((png_ptr->transformations & PNG_COMPOSE) != 0) - { - /* PNG_COMPOSE: png_set_background was called with need_expand false, - * so the color is in the color space of the output or png_set_alpha_mode - * was called and the color is black. Ignore RGB_TO_GRAY because that - * happens before GRAY_TO_RGB. - */ - if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) - { - if (png_ptr->background.red == png_ptr->background.green && - png_ptr->background.red == png_ptr->background.blue) - { - png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; - png_ptr->background.gray = png_ptr->background.red; - } - } - } -#endif /* READ_EXPAND && READ_BACKGROUND */ -#endif /* READ_GRAY_TO_RGB */ - - /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations - * can be performed directly on the palette, and some (such as rgb to gray) - * can be optimized inside the palette. This is particularly true of the - * composite (background and alpha) stuff, which can be pretty much all done - * in the palette even if the result is expanded to RGB or gray afterward. - * - * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and - * earlier and the palette stuff is actually handled on the first row. This - * leads to the reported bug that the palette returned by png_get_PLTE is not - * updated. - */ - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - png_init_palette_transformations(png_ptr); - - else - png_init_rgb_transformations(png_ptr); - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ - defined(PNG_READ_EXPAND_16_SUPPORTED) - if ((png_ptr->transformations & PNG_EXPAND_16) != 0 && - (png_ptr->transformations & PNG_COMPOSE) != 0 && - (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 && - png_ptr->bit_depth != 16) - { - /* TODO: fix this. Because the expand_16 operation is after the compose - * handling the background color must be 8, not 16, bits deep, but the - * application will supply a 16-bit value so reduce it here. - * - * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at - * present, so that case is ok (until do_expand_16 is moved.) - * - * NOTE: this discards the low 16 bits of the user supplied background - * color, but until expand_16 works properly there is no choice! - */ -# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x)) - CHOP(png_ptr->background.red); - CHOP(png_ptr->background.green); - CHOP(png_ptr->background.blue); - CHOP(png_ptr->background.gray); -# undef CHOP - } -#endif /* READ_BACKGROUND && READ_EXPAND_16 */ - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ - (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \ - defined(PNG_READ_STRIP_16_TO_8_SUPPORTED)) - if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 && - (png_ptr->transformations & PNG_COMPOSE) != 0 && - (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 && - png_ptr->bit_depth == 16) - { - /* On the other hand, if a 16-bit file is to be reduced to 8-bits per - * component this will also happen after PNG_COMPOSE and so the background - * color must be pre-expanded here. - * - * TODO: fix this too. - */ - png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257); - png_ptr->background.green = - (png_uint_16)(png_ptr->background.green * 257); - png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257); - png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257); - } -#endif - - /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the - * background support (see the comments in scripts/pnglibconf.dfa), this - * allows pre-multiplication of the alpha channel to be implemented as - * compositing on black. This is probably sub-optimal and has been done in - * 1.5.4 betas simply to enable external critique and testing (i.e. to - * implement the new API quickly, without lots of internal changes.) - */ - -#ifdef PNG_READ_GAMMA_SUPPORTED -# ifdef PNG_READ_BACKGROUND_SUPPORTED - /* Includes ALPHA_MODE */ - png_ptr->background_1 = png_ptr->background; -# endif - - /* This needs to change - in the palette image case a whole set of tables are - * built when it would be quicker to just calculate the correct value for - * each palette entry directly. Also, the test is too tricky - why check - * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that - * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the - * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction - * the gamma tables will not be built even if composition is required on a - * gamma encoded value. - * - * In 1.5.4 this is addressed below by an additional check on the individual - * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the - * tables. - */ - if ((png_ptr->transformations & PNG_GAMMA) != 0 || - ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 && - (png_gamma_significant(png_ptr->colorspace.gamma) != 0 || - png_gamma_significant(png_ptr->screen_gamma) != 0)) || - ((png_ptr->transformations & PNG_COMPOSE) != 0 && - (png_gamma_significant(png_ptr->colorspace.gamma) != 0 || - png_gamma_significant(png_ptr->screen_gamma) != 0 -# ifdef PNG_READ_BACKGROUND_SUPPORTED - || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE && - png_gamma_significant(png_ptr->background_gamma) != 0) -# endif - )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 && - png_gamma_significant(png_ptr->screen_gamma) != 0)) - { - png_build_gamma_table(png_ptr, png_ptr->bit_depth); - -#ifdef PNG_READ_BACKGROUND_SUPPORTED - if ((png_ptr->transformations & PNG_COMPOSE) != 0) - { - /* Issue a warning about this combination: because RGB_TO_GRAY is - * optimized to do the gamma transform if present yet do_background has - * to do the same thing if both options are set a - * double-gamma-correction happens. This is true in all versions of - * libpng to date. - */ - if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) - png_warning(png_ptr, - "libpng does not support gamma+background+rgb_to_gray"); - - if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0) - { - /* We don't get to here unless there is a tRNS chunk with non-opaque - * entries - see the checking code at the start of this function. - */ - png_color back, back_1; - png_colorp palette = png_ptr->palette; - int num_palette = png_ptr->num_palette; - int i; - if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) - { - - back.red = png_ptr->gamma_table[png_ptr->background.red]; - back.green = png_ptr->gamma_table[png_ptr->background.green]; - back.blue = png_ptr->gamma_table[png_ptr->background.blue]; - - back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; - back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; - back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; - } - else - { - png_fixed_point g, gs; - - switch (png_ptr->background_gamma_type) - { - case PNG_BACKGROUND_GAMMA_SCREEN: - g = (png_ptr->screen_gamma); - gs = PNG_FP_1; - break; - - case PNG_BACKGROUND_GAMMA_FILE: - g = png_reciprocal(png_ptr->colorspace.gamma); - gs = png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma); - break; - - case PNG_BACKGROUND_GAMMA_UNIQUE: - g = png_reciprocal(png_ptr->background_gamma); - gs = png_reciprocal2(png_ptr->background_gamma, - png_ptr->screen_gamma); - break; - default: - g = PNG_FP_1; /* back_1 */ - gs = PNG_FP_1; /* back */ - break; - } - - if (png_gamma_significant(gs) != 0) - { - back.red = png_gamma_8bit_correct(png_ptr->background.red, - gs); - back.green = png_gamma_8bit_correct(png_ptr->background.green, - gs); - back.blue = png_gamma_8bit_correct(png_ptr->background.blue, - gs); - } - - else - { - back.red = (png_byte)png_ptr->background.red; - back.green = (png_byte)png_ptr->background.green; - back.blue = (png_byte)png_ptr->background.blue; - } - - if (png_gamma_significant(g) != 0) - { - back_1.red = png_gamma_8bit_correct(png_ptr->background.red, - g); - back_1.green = png_gamma_8bit_correct( - png_ptr->background.green, g); - back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, - g); - } - - else - { - back_1.red = (png_byte)png_ptr->background.red; - back_1.green = (png_byte)png_ptr->background.green; - back_1.blue = (png_byte)png_ptr->background.blue; - } - } - - for (i = 0; i < num_palette; i++) - { - if (i < (int)png_ptr->num_trans && - png_ptr->trans_alpha[i] != 0xff) - { - if (png_ptr->trans_alpha[i] == 0) - { - palette[i] = back; - } - else /* if (png_ptr->trans_alpha[i] != 0xff) */ - { - png_byte v, w; - - v = png_ptr->gamma_to_1[palette[i].red]; - png_composite(w, v, png_ptr->trans_alpha[i], back_1.red); - palette[i].red = png_ptr->gamma_from_1[w]; - - v = png_ptr->gamma_to_1[palette[i].green]; - png_composite(w, v, png_ptr->trans_alpha[i], back_1.green); - palette[i].green = png_ptr->gamma_from_1[w]; - - v = png_ptr->gamma_to_1[palette[i].blue]; - png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue); - palette[i].blue = png_ptr->gamma_from_1[w]; - } - } - else - { - palette[i].red = png_ptr->gamma_table[palette[i].red]; - palette[i].green = png_ptr->gamma_table[palette[i].green]; - palette[i].blue = png_ptr->gamma_table[palette[i].blue]; - } - } - - /* Prevent the transformations being done again. - * - * NOTE: this is highly dubious; it removes the transformations in - * place. This seems inconsistent with the general treatment of the - * transformations elsewhere. - */ - png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA); - } /* color_type == PNG_COLOR_TYPE_PALETTE */ - - /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ - else /* color_type != PNG_COLOR_TYPE_PALETTE */ - { - int gs_sig, g_sig; - png_fixed_point g = PNG_FP_1; /* Correction to linear */ - png_fixed_point gs = PNG_FP_1; /* Correction to screen */ - - switch (png_ptr->background_gamma_type) - { - case PNG_BACKGROUND_GAMMA_SCREEN: - g = png_ptr->screen_gamma; - /* gs = PNG_FP_1; */ - break; - - case PNG_BACKGROUND_GAMMA_FILE: - g = png_reciprocal(png_ptr->colorspace.gamma); - gs = png_reciprocal2(png_ptr->colorspace.gamma, - png_ptr->screen_gamma); - break; - - case PNG_BACKGROUND_GAMMA_UNIQUE: - g = png_reciprocal(png_ptr->background_gamma); - gs = png_reciprocal2(png_ptr->background_gamma, - png_ptr->screen_gamma); - break; - - default: - png_error(png_ptr, "invalid background gamma type"); - } - - g_sig = png_gamma_significant(g); - gs_sig = png_gamma_significant(gs); - - if (g_sig != 0) - png_ptr->background_1.gray = png_gamma_correct(png_ptr, - png_ptr->background.gray, g); - - if (gs_sig != 0) - png_ptr->background.gray = png_gamma_correct(png_ptr, - png_ptr->background.gray, gs); - - if ((png_ptr->background.red != png_ptr->background.green) || - (png_ptr->background.red != png_ptr->background.blue) || - (png_ptr->background.red != png_ptr->background.gray)) - { - /* RGB or RGBA with color background */ - if (g_sig != 0) - { - png_ptr->background_1.red = png_gamma_correct(png_ptr, - png_ptr->background.red, g); - - png_ptr->background_1.green = png_gamma_correct(png_ptr, - png_ptr->background.green, g); - - png_ptr->background_1.blue = png_gamma_correct(png_ptr, - png_ptr->background.blue, g); - } - - if (gs_sig != 0) - { - png_ptr->background.red = png_gamma_correct(png_ptr, - png_ptr->background.red, gs); - - png_ptr->background.green = png_gamma_correct(png_ptr, - png_ptr->background.green, gs); - - png_ptr->background.blue = png_gamma_correct(png_ptr, - png_ptr->background.blue, gs); - } - } - - else - { - /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ - png_ptr->background_1.red = png_ptr->background_1.green - = png_ptr->background_1.blue = png_ptr->background_1.gray; - - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; - } - - /* The background is now in screen gamma: */ - png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN; - } /* color_type != PNG_COLOR_TYPE_PALETTE */ - }/* png_ptr->transformations & PNG_BACKGROUND */ - - else - /* Transformation does not include PNG_BACKGROUND */ -#endif /* READ_BACKGROUND */ - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED - /* RGB_TO_GRAY needs to have non-gamma-corrected values! */ - && ((png_ptr->transformations & PNG_EXPAND) == 0 || - (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) -#endif - ) - { - png_colorp palette = png_ptr->palette; - int num_palette = png_ptr->num_palette; - int i; - - /* NOTE: there are other transformations that should probably be in - * here too. - */ - for (i = 0; i < num_palette; i++) - { - palette[i].red = png_ptr->gamma_table[palette[i].red]; - palette[i].green = png_ptr->gamma_table[palette[i].green]; - palette[i].blue = png_ptr->gamma_table[palette[i].blue]; - } - - /* Done the gamma correction. */ - png_ptr->transformations &= ~PNG_GAMMA; - } /* color_type == PALETTE && !PNG_BACKGROUND transformation */ - } -#ifdef PNG_READ_BACKGROUND_SUPPORTED - else -#endif -#endif /* READ_GAMMA */ - -#ifdef PNG_READ_BACKGROUND_SUPPORTED - /* No GAMMA transformation (see the hanging else 4 lines above) */ - if ((png_ptr->transformations & PNG_COMPOSE) != 0 && - (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) - { - int i; - int istop = (int)png_ptr->num_trans; - png_color back; - png_colorp palette = png_ptr->palette; - - back.red = (png_byte)png_ptr->background.red; - back.green = (png_byte)png_ptr->background.green; - back.blue = (png_byte)png_ptr->background.blue; - - for (i = 0; i < istop; i++) - { - if (png_ptr->trans_alpha[i] == 0) - { - palette[i] = back; - } - - else if (png_ptr->trans_alpha[i] != 0xff) - { - /* The png_composite() macro is defined in png.h */ - png_composite(palette[i].red, palette[i].red, - png_ptr->trans_alpha[i], back.red); - - png_composite(palette[i].green, palette[i].green, - png_ptr->trans_alpha[i], back.green); - - png_composite(palette[i].blue, palette[i].blue, - png_ptr->trans_alpha[i], back.blue); - } - } - - png_ptr->transformations &= ~PNG_COMPOSE; - } -#endif /* READ_BACKGROUND */ - -#ifdef PNG_READ_SHIFT_SUPPORTED - if ((png_ptr->transformations & PNG_SHIFT) != 0 && - (png_ptr->transformations & PNG_EXPAND) == 0 && - (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) - { - int i; - int istop = png_ptr->num_palette; - int shift = 8 - png_ptr->sig_bit.red; - - png_ptr->transformations &= ~PNG_SHIFT; - - /* significant bits can be in the range 1 to 7 for a meaninful result, if - * the number of significant bits is 0 then no shift is done (this is an - * error condition which is silently ignored.) - */ - if (shift > 0 && shift < 8) - for (i=0; i<istop; ++i) - { - int component = png_ptr->palette[i].red; - - component >>= shift; - png_ptr->palette[i].red = (png_byte)component; - } - - shift = 8 - png_ptr->sig_bit.green; - if (shift > 0 && shift < 8) - for (i=0; i<istop; ++i) - { - int component = png_ptr->palette[i].green; - - component >>= shift; - png_ptr->palette[i].green = (png_byte)component; - } - - shift = 8 - png_ptr->sig_bit.blue; - if (shift > 0 && shift < 8) - for (i=0; i<istop; ++i) - { - int component = png_ptr->palette[i].blue; - - component >>= shift; - png_ptr->palette[i].blue = (png_byte)component; - } - } -#endif /* READ_SHIFT */ -} - -/* Modify the info structure to reflect the transformations. The - * info should be updated so a PNG file could be written with it, - * assuming the transformations result in valid PNG data. - */ -void /* PRIVATE */ -png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr) -{ - png_debug(1, "in png_read_transform_info"); - -#ifdef PNG_READ_EXPAND_SUPPORTED - if ((png_ptr->transformations & PNG_EXPAND) != 0) - { - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - /* This check must match what actually happens in - * png_do_expand_palette; if it ever checks the tRNS chunk to see if - * it is all opaque we must do the same (at present it does not.) - */ - if (png_ptr->num_trans > 0) - info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; - - else - info_ptr->color_type = PNG_COLOR_TYPE_RGB; - - info_ptr->bit_depth = 8; - info_ptr->num_trans = 0; - - if (png_ptr->palette == NULL) - png_error (png_ptr, "Palette is NULL in indexed image"); - } - else - { - if (png_ptr->num_trans != 0) - { - if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0) - info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; - } - if (info_ptr->bit_depth < 8) - info_ptr->bit_depth = 8; - - info_ptr->num_trans = 0; - } - } -#endif - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) - /* The following is almost certainly wrong unless the background value is in - * the screen space! - */ - if ((png_ptr->transformations & PNG_COMPOSE) != 0) - info_ptr->background = png_ptr->background; -#endif - -#ifdef PNG_READ_GAMMA_SUPPORTED - /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4), - * however it seems that the code in png_init_read_transformations, which has - * been called before this from png_read_update_info->png_read_start_row - * sometimes does the gamma transform and cancels the flag. - * - * TODO: this looks wrong; the info_ptr should end up with a gamma equal to - * the screen_gamma value. The following probably results in weirdness if - * the info_ptr is used by the app after the rows have been read. - */ - info_ptr->colorspace.gamma = png_ptr->colorspace.gamma; -#endif - - if (info_ptr->bit_depth == 16) - { -# ifdef PNG_READ_16BIT_SUPPORTED -# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED - if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0) - info_ptr->bit_depth = 8; -# endif - -# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED - if ((png_ptr->transformations & PNG_16_TO_8) != 0) - info_ptr->bit_depth = 8; -# endif - -# else - /* No 16-bit support: force chopping 16-bit input down to 8, in this case - * the app program can chose if both APIs are available by setting the - * correct scaling to use. - */ -# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED - /* For compatibility with previous versions use the strip method by - * default. This code works because if PNG_SCALE_16_TO_8 is already - * set the code below will do that in preference to the chop. - */ - png_ptr->transformations |= PNG_16_TO_8; - info_ptr->bit_depth = 8; -# else - -# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED - png_ptr->transformations |= PNG_SCALE_16_TO_8; - info_ptr->bit_depth = 8; -# else - - CONFIGURATION ERROR: you must enable at least one 16 to 8 method -# endif -# endif -#endif /* !READ_16BIT */ - } - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED - if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) - info_ptr->color_type = (png_byte)(info_ptr->color_type | - PNG_COLOR_MASK_COLOR); -#endif - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED - if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) - info_ptr->color_type = (png_byte)(info_ptr->color_type & - ~PNG_COLOR_MASK_COLOR); -#endif - -#ifdef PNG_READ_QUANTIZE_SUPPORTED - if ((png_ptr->transformations & PNG_QUANTIZE) != 0) - { - if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || - (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && - png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8) - { - info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; - } - } -#endif - -#ifdef PNG_READ_EXPAND_16_SUPPORTED - if ((png_ptr->transformations & PNG_EXPAND_16) != 0 && - info_ptr->bit_depth == 8 && - info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) - { - info_ptr->bit_depth = 16; - } -#endif - -#ifdef PNG_READ_PACK_SUPPORTED - if ((png_ptr->transformations & PNG_PACK) != 0 && - (info_ptr->bit_depth < 8)) - info_ptr->bit_depth = 8; -#endif - - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - info_ptr->channels = 1; - - else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) - info_ptr->channels = 3; - - else - info_ptr->channels = 1; - -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0) - { - info_ptr->color_type = (png_byte)(info_ptr->color_type & - ~PNG_COLOR_MASK_ALPHA); - info_ptr->num_trans = 0; - } -#endif - - if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) - info_ptr->channels++; - -#ifdef PNG_READ_FILLER_SUPPORTED - /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ - if ((png_ptr->transformations & PNG_FILLER) != 0 && - (info_ptr->color_type == PNG_COLOR_TYPE_RGB || - info_ptr->color_type == PNG_COLOR_TYPE_GRAY)) - { - info_ptr->channels++; - /* If adding a true alpha channel not just filler */ - if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0) - info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; - } -#endif - -#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ -defined(PNG_READ_USER_TRANSFORM_SUPPORTED) - if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) - { - if (png_ptr->user_transform_depth != 0) - info_ptr->bit_depth = png_ptr->user_transform_depth; - - if (png_ptr->user_transform_channels != 0) - info_ptr->channels = png_ptr->user_transform_channels; - } -#endif - - info_ptr->pixel_depth = (png_byte)(info_ptr->channels * - info_ptr->bit_depth); - - info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); - - /* Adding in 1.5.4: cache the above value in png_struct so that we can later - * check in png_rowbytes that the user buffer won't get overwritten. Note - * that the field is not always set - if png_read_update_info isn't called - * the application has to either not do any transforms or get the calculation - * right itself. - */ - png_ptr->info_rowbytes = info_ptr->rowbytes; - -#ifndef PNG_READ_EXPAND_SUPPORTED - if (png_ptr != NULL) - return; -#endif -} - -#ifdef PNG_READ_PACK_SUPPORTED -/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, - * without changing the actual values. Thus, if you had a row with - * a bit depth of 1, you would end up with bytes that only contained - * the numbers 0 or 1. If you would rather they contain 0 and 255, use - * png_do_shift() after this. - */ -static void -png_do_unpack(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_unpack"); - - if (row_info->bit_depth < 8) - { - png_uint_32 i; - png_uint_32 row_width=row_info->width; - - switch (row_info->bit_depth) - { - case 1: - { - png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); - png_bytep dp = row + (png_size_t)row_width - 1; - png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); - for (i = 0; i < row_width; i++) - { - *dp = (png_byte)((*sp >> shift) & 0x01); - - if (shift == 7) - { - shift = 0; - sp--; - } - - else - shift++; - - dp--; - } - break; - } - - case 2: - { - - png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); - png_bytep dp = row + (png_size_t)row_width - 1; - png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); - for (i = 0; i < row_width; i++) - { - *dp = (png_byte)((*sp >> shift) & 0x03); - - if (shift == 6) - { - shift = 0; - sp--; - } - - else - shift += 2; - - dp--; - } - break; - } - - case 4: - { - png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); - png_bytep dp = row + (png_size_t)row_width - 1; - png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); - for (i = 0; i < row_width; i++) - { - *dp = (png_byte)((*sp >> shift) & 0x0f); - - if (shift == 4) - { - shift = 0; - sp--; - } - - else - shift = 4; - - dp--; - } - break; - } - - default: - break; - } - row_info->bit_depth = 8; - row_info->pixel_depth = (png_byte)(8 * row_info->channels); - row_info->rowbytes = row_width * row_info->channels; - } -} -#endif - -#ifdef PNG_READ_SHIFT_SUPPORTED -/* Reverse the effects of png_do_shift. This routine merely shifts the - * pixels back to their significant bits values. Thus, if you have - * a row of bit depth 8, but only 5 are significant, this will shift - * the values back to 0 through 31. - */ -static void -png_do_unshift(png_row_infop row_info, png_bytep row, - png_const_color_8p sig_bits) -{ - int color_type; - - png_debug(1, "in png_do_unshift"); - - /* The palette case has already been handled in the _init routine. */ - color_type = row_info->color_type; - - if (color_type != PNG_COLOR_TYPE_PALETTE) - { - int shift[4]; - int channels = 0; - int bit_depth = row_info->bit_depth; - - if ((color_type & PNG_COLOR_MASK_COLOR) != 0) - { - shift[channels++] = bit_depth - sig_bits->red; - shift[channels++] = bit_depth - sig_bits->green; - shift[channels++] = bit_depth - sig_bits->blue; - } - - else - { - shift[channels++] = bit_depth - sig_bits->gray; - } - - if ((color_type & PNG_COLOR_MASK_ALPHA) != 0) - { - shift[channels++] = bit_depth - sig_bits->alpha; - } - - { - int c, have_shift; - - for (c = have_shift = 0; c < channels; ++c) - { - /* A shift of more than the bit depth is an error condition but it - * gets ignored here. - */ - if (shift[c] <= 0 || shift[c] >= bit_depth) - shift[c] = 0; - - else - have_shift = 1; - } - - if (have_shift == 0) - return; - } - - switch (bit_depth) - { - default: - /* Must be 1bpp gray: should not be here! */ - /* NOTREACHED */ - break; - - case 2: - /* Must be 2bpp gray */ - /* assert(channels == 1 && shift[0] == 1) */ - { - png_bytep bp = row; - png_bytep bp_end = bp + row_info->rowbytes; - - while (bp < bp_end) - { - int b = (*bp >> 1) & 0x55; - *bp++ = (png_byte)b; - } - break; - } - - case 4: - /* Must be 4bpp gray */ - /* assert(channels == 1) */ - { - png_bytep bp = row; - png_bytep bp_end = bp + row_info->rowbytes; - int gray_shift = shift[0]; - int mask = 0xf >> gray_shift; - - mask |= mask << 4; - - while (bp < bp_end) - { - int b = (*bp >> gray_shift) & mask; - *bp++ = (png_byte)b; - } - break; - } - - case 8: - /* Single byte components, G, GA, RGB, RGBA */ - { - png_bytep bp = row; - png_bytep bp_end = bp + row_info->rowbytes; - int channel = 0; - - while (bp < bp_end) - { - int b = *bp >> shift[channel]; - if (++channel >= channels) - channel = 0; - *bp++ = (png_byte)b; - } - break; - } - -#ifdef PNG_READ_16BIT_SUPPORTED - case 16: - /* Double byte components, G, GA, RGB, RGBA */ - { - png_bytep bp = row; - png_bytep bp_end = bp + row_info->rowbytes; - int channel = 0; - - while (bp < bp_end) - { - int value = (bp[0] << 8) + bp[1]; - - value >>= shift[channel]; - if (++channel >= channels) - channel = 0; - *bp++ = (png_byte)(value >> 8); - *bp++ = (png_byte)value; - } - break; - } -#endif - } - } -} -#endif - -#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED -/* Scale rows of bit depth 16 down to 8 accurately */ -static void -png_do_scale_16_to_8(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_scale_16_to_8"); - - if (row_info->bit_depth == 16) - { - png_bytep sp = row; /* source */ - png_bytep dp = row; /* destination */ - png_bytep ep = sp + row_info->rowbytes; /* end+1 */ - - while (sp < ep) - { - /* The input is an array of 16-bit components, these must be scaled to - * 8 bits each. For a 16-bit value V the required value (from the PNG - * specification) is: - * - * (V * 255) / 65535 - * - * This reduces to round(V / 257), or floor((V + 128.5)/257) - * - * Represent V as the two byte value vhi.vlo. Make a guess that the - * result is the top byte of V, vhi, then the correction to this value - * is: - * - * error = floor(((V-vhi.vhi) + 128.5) / 257) - * = floor(((vlo-vhi) + 128.5) / 257) - * - * This can be approximated using integer arithmetic (and a signed - * shift): - * - * error = (vlo-vhi+128) >> 8; - * - * The approximate differs from the exact answer only when (vlo-vhi) is - * 128; it then gives a correction of +1 when the exact correction is - * 0. This gives 128 errors. The exact answer (correct for all 16-bit - * input values) is: - * - * error = (vlo-vhi+128)*65535 >> 24; - * - * An alternative arithmetic calculation which also gives no errors is: - * - * (V * 255 + 32895) >> 16 - */ - - png_int_32 tmp = *sp++; /* must be signed! */ - tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24; - *dp++ = (png_byte)tmp; - } - - row_info->bit_depth = 8; - row_info->pixel_depth = (png_byte)(8 * row_info->channels); - row_info->rowbytes = row_info->width * row_info->channels; - } -} -#endif - -#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED -static void -/* Simply discard the low byte. This was the default behavior prior - * to libpng-1.5.4. - */ -png_do_chop(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_chop"); - - if (row_info->bit_depth == 16) - { - png_bytep sp = row; /* source */ - png_bytep dp = row; /* destination */ - png_bytep ep = sp + row_info->rowbytes; /* end+1 */ - - while (sp < ep) - { - *dp++ = *sp; - sp += 2; /* skip low byte */ - } - - row_info->bit_depth = 8; - row_info->pixel_depth = (png_byte)(8 * row_info->channels); - row_info->rowbytes = row_info->width * row_info->channels; - } -} -#endif - -#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED -static void -png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_read_swap_alpha"); - - { - png_uint_32 row_width = row_info->width; - if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - { - /* This converts from RGBA to ARGB */ - if (row_info->bit_depth == 8) - { - png_bytep sp = row + row_info->rowbytes; - png_bytep dp = sp; - png_byte save; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - save = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = save; - } - } - -#ifdef PNG_READ_16BIT_SUPPORTED - /* This converts from RRGGBBAA to AARRGGBB */ - else - { - png_bytep sp = row + row_info->rowbytes; - png_bytep dp = sp; - png_byte save[2]; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - save[0] = *(--sp); - save[1] = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = save[0]; - *(--dp) = save[1]; - } - } -#endif - } - - else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - { - /* This converts from GA to AG */ - if (row_info->bit_depth == 8) - { - png_bytep sp = row + row_info->rowbytes; - png_bytep dp = sp; - png_byte save; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - save = *(--sp); - *(--dp) = *(--sp); - *(--dp) = save; - } - } - -#ifdef PNG_READ_16BIT_SUPPORTED - /* This converts from GGAA to AAGG */ - else - { - png_bytep sp = row + row_info->rowbytes; - png_bytep dp = sp; - png_byte save[2]; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - save[0] = *(--sp); - save[1] = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = save[0]; - *(--dp) = save[1]; - } - } -#endif - } - } -} -#endif - -#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED -static void -png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) -{ - png_uint_32 row_width; - png_debug(1, "in png_do_read_invert_alpha"); - - row_width = row_info->width; - if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - { - if (row_info->bit_depth == 8) - { - /* This inverts the alpha channel in RGBA */ - png_bytep sp = row + row_info->rowbytes; - png_bytep dp = sp; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - *(--dp) = (png_byte)(255 - *(--sp)); - -/* This does nothing: - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - We can replace it with: -*/ - sp-=3; - dp=sp; - } - } - -#ifdef PNG_READ_16BIT_SUPPORTED - /* This inverts the alpha channel in RRGGBBAA */ - else - { - png_bytep sp = row + row_info->rowbytes; - png_bytep dp = sp; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - *(--dp) = (png_byte)(255 - *(--sp)); - *(--dp) = (png_byte)(255 - *(--sp)); - -/* This does nothing: - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - We can replace it with: -*/ - sp-=6; - dp=sp; - } - } -#endif - } - else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - { - if (row_info->bit_depth == 8) - { - /* This inverts the alpha channel in GA */ - png_bytep sp = row + row_info->rowbytes; - png_bytep dp = sp; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - *(--dp) = (png_byte)(255 - *(--sp)); - *(--dp) = *(--sp); - } - } - -#ifdef PNG_READ_16BIT_SUPPORTED - else - { - /* This inverts the alpha channel in GGAA */ - png_bytep sp = row + row_info->rowbytes; - png_bytep dp = sp; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - *(--dp) = (png_byte)(255 - *(--sp)); - *(--dp) = (png_byte)(255 - *(--sp)); -/* - *(--dp) = *(--sp); - *(--dp) = *(--sp); -*/ - sp-=2; - dp=sp; - } - } -#endif - } -} -#endif - -#ifdef PNG_READ_FILLER_SUPPORTED -/* Add filler channel if we have RGB color */ -static void -png_do_read_filler(png_row_infop row_info, png_bytep row, - png_uint_32 filler, png_uint_32 flags) -{ - png_uint_32 i; - png_uint_32 row_width = row_info->width; - -#ifdef PNG_READ_16BIT_SUPPORTED - png_byte hi_filler = (png_byte)(filler>>8); -#endif - png_byte lo_filler = (png_byte)filler; - - png_debug(1, "in png_do_read_filler"); - - if ( - row_info->color_type == PNG_COLOR_TYPE_GRAY) - { - if (row_info->bit_depth == 8) - { - if ((flags & PNG_FLAG_FILLER_AFTER) != 0) - { - /* This changes the data from G to GX */ - png_bytep sp = row + (png_size_t)row_width; - png_bytep dp = sp + (png_size_t)row_width; - for (i = 1; i < row_width; i++) - { - *(--dp) = lo_filler; - *(--dp) = *(--sp); - } - *(--dp) = lo_filler; - row_info->channels = 2; - row_info->pixel_depth = 16; - row_info->rowbytes = row_width * 2; - } - - else - { - /* This changes the data from G to XG */ - png_bytep sp = row + (png_size_t)row_width; - png_bytep dp = sp + (png_size_t)row_width; - for (i = 0; i < row_width; i++) - { - *(--dp) = *(--sp); - *(--dp) = lo_filler; - } - row_info->channels = 2; - row_info->pixel_depth = 16; - row_info->rowbytes = row_width * 2; - } - } - -#ifdef PNG_READ_16BIT_SUPPORTED - else if (row_info->bit_depth == 16) - { - if ((flags & PNG_FLAG_FILLER_AFTER) != 0) - { - /* This changes the data from GG to GGXX */ - png_bytep sp = row + (png_size_t)row_width * 2; - png_bytep dp = sp + (png_size_t)row_width * 2; - for (i = 1; i < row_width; i++) - { - *(--dp) = lo_filler; - *(--dp) = hi_filler; - *(--dp) = *(--sp); - *(--dp) = *(--sp); - } - *(--dp) = lo_filler; - *(--dp) = hi_filler; - row_info->channels = 2; - row_info->pixel_depth = 32; - row_info->rowbytes = row_width * 4; - } - - else - { - /* This changes the data from GG to XXGG */ - png_bytep sp = row + (png_size_t)row_width * 2; - png_bytep dp = sp + (png_size_t)row_width * 2; - for (i = 0; i < row_width; i++) - { - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = lo_filler; - *(--dp) = hi_filler; - } - row_info->channels = 2; - row_info->pixel_depth = 32; - row_info->rowbytes = row_width * 4; - } - } -#endif - } /* COLOR_TYPE == GRAY */ - else if (row_info->color_type == PNG_COLOR_TYPE_RGB) - { - if (row_info->bit_depth == 8) - { - if ((flags & PNG_FLAG_FILLER_AFTER) != 0) - { - /* This changes the data from RGB to RGBX */ - png_bytep sp = row + (png_size_t)row_width * 3; - png_bytep dp = sp + (png_size_t)row_width; - for (i = 1; i < row_width; i++) - { - *(--dp) = lo_filler; - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - } - *(--dp) = lo_filler; - row_info->channels = 4; - row_info->pixel_depth = 32; - row_info->rowbytes = row_width * 4; - } - - else - { - /* This changes the data from RGB to XRGB */ - png_bytep sp = row + (png_size_t)row_width * 3; - png_bytep dp = sp + (png_size_t)row_width; - for (i = 0; i < row_width; i++) - { - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = lo_filler; - } - row_info->channels = 4; - row_info->pixel_depth = 32; - row_info->rowbytes = row_width * 4; - } - } - -#ifdef PNG_READ_16BIT_SUPPORTED - else if (row_info->bit_depth == 16) - { - if ((flags & PNG_FLAG_FILLER_AFTER) != 0) - { - /* This changes the data from RRGGBB to RRGGBBXX */ - png_bytep sp = row + (png_size_t)row_width * 6; - png_bytep dp = sp + (png_size_t)row_width * 2; - for (i = 1; i < row_width; i++) - { - *(--dp) = lo_filler; - *(--dp) = hi_filler; - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - } - *(--dp) = lo_filler; - *(--dp) = hi_filler; - row_info->channels = 4; - row_info->pixel_depth = 64; - row_info->rowbytes = row_width * 8; - } - - else - { - /* This changes the data from RRGGBB to XXRRGGBB */ - png_bytep sp = row + (png_size_t)row_width * 6; - png_bytep dp = sp + (png_size_t)row_width * 2; - for (i = 0; i < row_width; i++) - { - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = *(--sp); - *(--dp) = lo_filler; - *(--dp) = hi_filler; - } - - row_info->channels = 4; - row_info->pixel_depth = 64; - row_info->rowbytes = row_width * 8; - } - } -#endif - } /* COLOR_TYPE == RGB */ -} -#endif - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED -/* Expand grayscale files to RGB, with or without alpha */ -static void -png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) -{ - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - png_debug(1, "in png_do_gray_to_rgb"); - - if (row_info->bit_depth >= 8 && - (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0) - { - if (row_info->color_type == PNG_COLOR_TYPE_GRAY) - { - if (row_info->bit_depth == 8) - { - /* This changes G to RGB */ - png_bytep sp = row + (png_size_t)row_width - 1; - png_bytep dp = sp + (png_size_t)row_width * 2; - for (i = 0; i < row_width; i++) - { - *(dp--) = *sp; - *(dp--) = *sp; - *(dp--) = *(sp--); - } - } - - else - { - /* This changes GG to RRGGBB */ - png_bytep sp = row + (png_size_t)row_width * 2 - 1; - png_bytep dp = sp + (png_size_t)row_width * 4; - for (i = 0; i < row_width; i++) - { - *(dp--) = *sp; - *(dp--) = *(sp - 1); - *(dp--) = *sp; - *(dp--) = *(sp - 1); - *(dp--) = *(sp--); - *(dp--) = *(sp--); - } - } - } - - else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - { - if (row_info->bit_depth == 8) - { - /* This changes GA to RGBA */ - png_bytep sp = row + (png_size_t)row_width * 2 - 1; - png_bytep dp = sp + (png_size_t)row_width * 2; - for (i = 0; i < row_width; i++) - { - *(dp--) = *(sp--); - *(dp--) = *sp; - *(dp--) = *sp; - *(dp--) = *(sp--); - } - } - - else - { - /* This changes GGAA to RRGGBBAA */ - png_bytep sp = row + (png_size_t)row_width * 4 - 1; - png_bytep dp = sp + (png_size_t)row_width * 4; - for (i = 0; i < row_width; i++) - { - *(dp--) = *(sp--); - *(dp--) = *(sp--); - *(dp--) = *sp; - *(dp--) = *(sp - 1); - *(dp--) = *sp; - *(dp--) = *(sp - 1); - *(dp--) = *(sp--); - *(dp--) = *(sp--); - } - } - } - row_info->channels = (png_byte)(row_info->channels + 2); - row_info->color_type |= PNG_COLOR_MASK_COLOR; - row_info->pixel_depth = (png_byte)(row_info->channels * - row_info->bit_depth); - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); - } -} -#endif - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -/* Reduce RGB files to grayscale, with or without alpha - * using the equation given in Poynton's ColorFAQ of 1998-01-04 at - * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but - * versions dated 1998 through November 2002 have been archived at - * http://web.archive.org/web/20000816232553/http://www.inforamp.net/ - * ~poynton/notes/colour_and_gamma/ColorFAQ.txt ) - * Charles Poynton poynton at poynton.com - * - * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B - * - * which can be expressed with integers as - * - * Y = (6969 * R + 23434 * G + 2365 * B)/32768 - * - * Poynton's current link (as of January 2003 through July 2011): - * <http://www.poynton.com/notes/colour_and_gamma/> - * has changed the numbers slightly: - * - * Y = 0.2126*R + 0.7152*G + 0.0722*B - * - * which can be expressed with integers as - * - * Y = (6966 * R + 23436 * G + 2366 * B)/32768 - * - * Historically, however, libpng uses numbers derived from the ITU-R Rec 709 - * end point chromaticities and the D65 white point. Depending on the - * precision used for the D65 white point this produces a variety of different - * numbers, however if the four decimal place value used in ITU-R Rec 709 is - * used (0.3127,0.3290) the Y calculation would be: - * - * Y = (6968 * R + 23435 * G + 2366 * B)/32768 - * - * While this is correct the rounding results in an overflow for white, because - * the sum of the rounded coefficients is 32769, not 32768. Consequently - * libpng uses, instead, the closest non-overflowing approximation: - * - * Y = (6968 * R + 23434 * G + 2366 * B)/32768 - * - * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk - * (including an sRGB chunk) then the chromaticities are used to calculate the - * coefficients. See the chunk handling in pngrutil.c for more information. - * - * In all cases the calculation is to be done in a linear colorspace. If no - * gamma information is available to correct the encoding of the original RGB - * values this results in an implicit assumption that the original PNG RGB - * values were linear. - * - * Other integer coefficents can be used via png_set_rgb_to_gray(). Because - * the API takes just red and green coefficients the blue coefficient is - * calculated to make the sum 32768. This will result in different rounding - * to that used above. - */ -static int -png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row) - -{ - int rgb_error = 0; - - png_debug(1, "in png_do_rgb_to_gray"); - - if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 && - (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) - { - PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; - PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; - PNG_CONST png_uint_32 bc = 32768 - rc - gc; - PNG_CONST png_uint_32 row_width = row_info->width; - PNG_CONST int have_alpha = - (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0; - - if (row_info->bit_depth == 8) - { -#ifdef PNG_READ_GAMMA_SUPPORTED - /* Notice that gamma to/from 1 are not necessarily inverses (if - * there is an overall gamma correction). Prior to 1.5.5 this code - * checked the linearized values for equality; this doesn't match - * the documentation, the original values must be checked. - */ - if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) - { - png_bytep sp = row; - png_bytep dp = row; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - png_byte red = *(sp++); - png_byte green = *(sp++); - png_byte blue = *(sp++); - - if (red != green || red != blue) - { - red = png_ptr->gamma_to_1[red]; - green = png_ptr->gamma_to_1[green]; - blue = png_ptr->gamma_to_1[blue]; - - rgb_error |= 1; - *(dp++) = png_ptr->gamma_from_1[ - (rc*red + gc*green + bc*blue + 16384)>>15]; - } - - else - { - /* If there is no overall correction the table will not be - * set. - */ - if (png_ptr->gamma_table != NULL) - red = png_ptr->gamma_table[red]; - - *(dp++) = red; - } - - if (have_alpha != 0) - *(dp++) = *(sp++); - } - } - else -#endif - { - png_bytep sp = row; - png_bytep dp = row; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - png_byte red = *(sp++); - png_byte green = *(sp++); - png_byte blue = *(sp++); - - if (red != green || red != blue) - { - rgb_error |= 1; - /* NOTE: this is the historical approach which simply - * truncates the results. - */ - *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); - } - - else - *(dp++) = red; - - if (have_alpha != 0) - *(dp++) = *(sp++); - } - } - } - - else /* RGB bit_depth == 16 */ - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL) - { - png_bytep sp = row; - png_bytep dp = row; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - png_uint_16 red, green, blue, w; - png_byte hi,lo; - - hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo)); - hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo)); - hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo)); - - if (red == green && red == blue) - { - if (png_ptr->gamma_16_table != NULL) - w = png_ptr->gamma_16_table[(red & 0xff) - >> png_ptr->gamma_shift][red >> 8]; - - else - w = red; - } - - else - { - png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red & 0xff) - >> png_ptr->gamma_shift][red>>8]; - png_uint_16 green_1 = - png_ptr->gamma_16_to_1[(green & 0xff) >> - png_ptr->gamma_shift][green>>8]; - png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue & 0xff) - >> png_ptr->gamma_shift][blue>>8]; - png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 - + bc*blue_1 + 16384)>>15); - w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >> - png_ptr->gamma_shift][gray16 >> 8]; - rgb_error |= 1; - } - - *(dp++) = (png_byte)((w>>8) & 0xff); - *(dp++) = (png_byte)(w & 0xff); - - if (have_alpha != 0) - { - *(dp++) = *(sp++); - *(dp++) = *(sp++); - } - } - } - else -#endif - { - png_bytep sp = row; - png_bytep dp = row; - png_uint_32 i; - - for (i = 0; i < row_width; i++) - { - png_uint_16 red, green, blue, gray16; - png_byte hi,lo; - - hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo)); - hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo)); - hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo)); - - if (red != green || red != blue) - rgb_error |= 1; - - /* From 1.5.5 in the 16-bit case do the accurate conversion even - * in the 'fast' case - this is because this is where the code - * ends up when handling linear 16-bit data. - */ - gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >> - 15); - *(dp++) = (png_byte)((gray16 >> 8) & 0xff); - *(dp++) = (png_byte)(gray16 & 0xff); - - if (have_alpha != 0) - { - *(dp++) = *(sp++); - *(dp++) = *(sp++); - } - } - } - } - - row_info->channels = (png_byte)(row_info->channels - 2); - row_info->color_type = (png_byte)(row_info->color_type & - ~PNG_COLOR_MASK_COLOR); - row_info->pixel_depth = (png_byte)(row_info->channels * - row_info->bit_depth); - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); - } - return rgb_error; -} -#endif - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) -/* Replace any alpha or transparency with the supplied background color. - * "background" is already in the screen gamma, while "background_1" is - * at a gamma of 1.0. Paletted files have already been taken care of. - */ -static void -png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr) -{ -#ifdef PNG_READ_GAMMA_SUPPORTED - png_const_bytep gamma_table = png_ptr->gamma_table; - png_const_bytep gamma_from_1 = png_ptr->gamma_from_1; - png_const_bytep gamma_to_1 = png_ptr->gamma_to_1; - png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table; - png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1; - png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1; - int gamma_shift = png_ptr->gamma_shift; - int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; -#endif - - png_bytep sp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - int shift; - - png_debug(1, "in png_do_compose"); - - { - switch (row_info->color_type) - { - case PNG_COLOR_TYPE_GRAY: - { - switch (row_info->bit_depth) - { - case 1: - { - sp = row; - shift = 7; - for (i = 0; i < row_width; i++) - { - if ((png_uint_16)((*sp >> shift) & 0x01) - == png_ptr->trans_color.gray) - { - unsigned int tmp = *sp & (0x7f7f >> (7 - shift)); - tmp |= png_ptr->background.gray << shift; - *sp = (png_byte)(tmp & 0xff); - } - - if (shift == 0) - { - shift = 7; - sp++; - } - - else - shift--; - } - break; - } - - case 2: - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_table != NULL) - { - sp = row; - shift = 6; - for (i = 0; i < row_width; i++) - { - if ((png_uint_16)((*sp >> shift) & 0x03) - == png_ptr->trans_color.gray) - { - unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); - tmp |= png_ptr->background.gray << shift; - *sp = (png_byte)(tmp & 0xff); - } - - else - { - unsigned int p = (*sp >> shift) & 0x03; - unsigned int g = (gamma_table [p | (p << 2) | - (p << 4) | (p << 6)] >> 6) & 0x03; - unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); - tmp |= g << shift; - *sp = (png_byte)(tmp & 0xff); - } - - if (shift == 0) - { - shift = 6; - sp++; - } - - else - shift -= 2; - } - } - - else -#endif - { - sp = row; - shift = 6; - for (i = 0; i < row_width; i++) - { - if ((png_uint_16)((*sp >> shift) & 0x03) - == png_ptr->trans_color.gray) - { - unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); - tmp |= png_ptr->background.gray << shift; - *sp = (png_byte)(tmp & 0xff); - } - - if (shift == 0) - { - shift = 6; - sp++; - } - - else - shift -= 2; - } - } - break; - } - - case 4: - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_table != NULL) - { - sp = row; - shift = 4; - for (i = 0; i < row_width; i++) - { - if ((png_uint_16)((*sp >> shift) & 0x0f) - == png_ptr->trans_color.gray) - { - unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); - tmp |= png_ptr->background.gray << shift; - *sp = (png_byte)(tmp & 0xff); - } - - else - { - unsigned int p = (*sp >> shift) & 0x0f; - unsigned int g = (gamma_table[p | (p << 4)] >> 4) & - 0x0f; - unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); - tmp |= g << shift; - *sp = (png_byte)(tmp & 0xff); - } - - if (shift == 0) - { - shift = 4; - sp++; - } - - else - shift -= 4; - } - } - - else -#endif - { - sp = row; - shift = 4; - for (i = 0; i < row_width; i++) - { - if ((png_uint_16)((*sp >> shift) & 0x0f) - == png_ptr->trans_color.gray) - { - unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); - tmp |= png_ptr->background.gray << shift; - *sp = (png_byte)(tmp & 0xff); - } - - if (shift == 0) - { - shift = 4; - sp++; - } - - else - shift -= 4; - } - } - break; - } - - case 8: - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_table != NULL) - { - sp = row; - for (i = 0; i < row_width; i++, sp++) - { - if (*sp == png_ptr->trans_color.gray) - *sp = (png_byte)png_ptr->background.gray; - - else - *sp = gamma_table[*sp]; - } - } - else -#endif - { - sp = row; - for (i = 0; i < row_width; i++, sp++) - { - if (*sp == png_ptr->trans_color.gray) - *sp = (png_byte)png_ptr->background.gray; - } - } - break; - } - - case 16: - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_16 != NULL) - { - sp = row; - for (i = 0; i < row_width; i++, sp += 2) - { - png_uint_16 v; - - v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - - if (v == png_ptr->trans_color.gray) - { - /* Background is already in screen gamma */ - *sp = (png_byte)((png_ptr->background.gray >> 8) - & 0xff); - *(sp + 1) = (png_byte)(png_ptr->background.gray - & 0xff); - } - - else - { - v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - } - } - } - else -#endif - { - sp = row; - for (i = 0; i < row_width; i++, sp += 2) - { - png_uint_16 v; - - v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - - if (v == png_ptr->trans_color.gray) - { - *sp = (png_byte)((png_ptr->background.gray >> 8) - & 0xff); - *(sp + 1) = (png_byte)(png_ptr->background.gray - & 0xff); - } - } - } - break; - } - - default: - break; - } - break; - } - - case PNG_COLOR_TYPE_RGB: - { - if (row_info->bit_depth == 8) - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_table != NULL) - { - sp = row; - for (i = 0; i < row_width; i++, sp += 3) - { - if (*sp == png_ptr->trans_color.red && - *(sp + 1) == png_ptr->trans_color.green && - *(sp + 2) == png_ptr->trans_color.blue) - { - *sp = (png_byte)png_ptr->background.red; - *(sp + 1) = (png_byte)png_ptr->background.green; - *(sp + 2) = (png_byte)png_ptr->background.blue; - } - - else - { - *sp = gamma_table[*sp]; - *(sp + 1) = gamma_table[*(sp + 1)]; - *(sp + 2) = gamma_table[*(sp + 2)]; - } - } - } - else -#endif - { - sp = row; - for (i = 0; i < row_width; i++, sp += 3) - { - if (*sp == png_ptr->trans_color.red && - *(sp + 1) == png_ptr->trans_color.green && - *(sp + 2) == png_ptr->trans_color.blue) - { - *sp = (png_byte)png_ptr->background.red; - *(sp + 1) = (png_byte)png_ptr->background.green; - *(sp + 2) = (png_byte)png_ptr->background.blue; - } - } - } - } - else /* if (row_info->bit_depth == 16) */ - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_16 != NULL) - { - sp = row; - for (i = 0; i < row_width; i++, sp += 6) - { - png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - - png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) - + *(sp + 3)); - - png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) - + *(sp + 5)); - - if (r == png_ptr->trans_color.red && - g == png_ptr->trans_color.green && - b == png_ptr->trans_color.blue) - { - /* Background is already in screen gamma */ - *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); - *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); - *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) - & 0xff); - *(sp + 3) = (png_byte)(png_ptr->background.green - & 0xff); - *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) - & 0xff); - *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); - } - - else - { - png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - - v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; - *(sp + 2) = (png_byte)((v >> 8) & 0xff); - *(sp + 3) = (png_byte)(v & 0xff); - - v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; - *(sp + 4) = (png_byte)((v >> 8) & 0xff); - *(sp + 5) = (png_byte)(v & 0xff); - } - } - } - - else -#endif - { - sp = row; - for (i = 0; i < row_width; i++, sp += 6) - { - png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - - png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) - + *(sp + 3)); - - png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) - + *(sp + 5)); - - if (r == png_ptr->trans_color.red && - g == png_ptr->trans_color.green && - b == png_ptr->trans_color.blue) - { - *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); - *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); - *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) - & 0xff); - *(sp + 3) = (png_byte)(png_ptr->background.green - & 0xff); - *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) - & 0xff); - *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); - } - } - } - } - break; - } - - case PNG_COLOR_TYPE_GRAY_ALPHA: - { - if (row_info->bit_depth == 8) - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_to_1 != NULL && gamma_from_1 != NULL && - gamma_table != NULL) - { - sp = row; - for (i = 0; i < row_width; i++, sp += 2) - { - png_uint_16 a = *(sp + 1); - - if (a == 0xff) - *sp = gamma_table[*sp]; - - else if (a == 0) - { - /* Background is already in screen gamma */ - *sp = (png_byte)png_ptr->background.gray; - } - - else - { - png_byte v, w; - - v = gamma_to_1[*sp]; - png_composite(w, v, a, png_ptr->background_1.gray); - if (optimize == 0) - w = gamma_from_1[w]; - *sp = w; - } - } - } - else -#endif - { - sp = row; - for (i = 0; i < row_width; i++, sp += 2) - { - png_byte a = *(sp + 1); - - if (a == 0) - *sp = (png_byte)png_ptr->background.gray; - - else if (a < 0xff) - png_composite(*sp, *sp, a, png_ptr->background.gray); - } - } - } - else /* if (png_ptr->bit_depth == 16) */ - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_16 != NULL && gamma_16_from_1 != NULL && - gamma_16_to_1 != NULL) - { - sp = row; - for (i = 0; i < row_width; i++, sp += 4) - { - png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) - + *(sp + 3)); - - if (a == (png_uint_16)0xffff) - { - png_uint_16 v; - - v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - } - - else if (a == 0) - { - /* Background is already in screen gamma */ - *sp = (png_byte)((png_ptr->background.gray >> 8) - & 0xff); - *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); - } - - else - { - png_uint_16 g, v, w; - - g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; - png_composite_16(v, g, a, png_ptr->background_1.gray); - if (optimize != 0) - w = v; - else - w = gamma_16_from_1[(v & 0xff) >> - gamma_shift][v >> 8]; - *sp = (png_byte)((w >> 8) & 0xff); - *(sp + 1) = (png_byte)(w & 0xff); - } - } - } - else -#endif - { - sp = row; - for (i = 0; i < row_width; i++, sp += 4) - { - png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) - + *(sp + 3)); - - if (a == 0) - { - *sp = (png_byte)((png_ptr->background.gray >> 8) - & 0xff); - *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); - } - - else if (a < 0xffff) - { - png_uint_16 g, v; - - g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - png_composite_16(v, g, a, png_ptr->background.gray); - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - } - } - } - } - break; - } - - case PNG_COLOR_TYPE_RGB_ALPHA: - { - if (row_info->bit_depth == 8) - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_to_1 != NULL && gamma_from_1 != NULL && - gamma_table != NULL) - { - sp = row; - for (i = 0; i < row_width; i++, sp += 4) - { - png_byte a = *(sp + 3); - - if (a == 0xff) - { - *sp = gamma_table[*sp]; - *(sp + 1) = gamma_table[*(sp + 1)]; - *(sp + 2) = gamma_table[*(sp + 2)]; - } - - else if (a == 0) - { - /* Background is already in screen gamma */ - *sp = (png_byte)png_ptr->background.red; - *(sp + 1) = (png_byte)png_ptr->background.green; - *(sp + 2) = (png_byte)png_ptr->background.blue; - } - - else - { - png_byte v, w; - - v = gamma_to_1[*sp]; - png_composite(w, v, a, png_ptr->background_1.red); - if (optimize == 0) w = gamma_from_1[w]; - *sp = w; - - v = gamma_to_1[*(sp + 1)]; - png_composite(w, v, a, png_ptr->background_1.green); - if (optimize == 0) w = gamma_from_1[w]; - *(sp + 1) = w; - - v = gamma_to_1[*(sp + 2)]; - png_composite(w, v, a, png_ptr->background_1.blue); - if (optimize == 0) w = gamma_from_1[w]; - *(sp + 2) = w; - } - } - } - else -#endif - { - sp = row; - for (i = 0; i < row_width; i++, sp += 4) - { - png_byte a = *(sp + 3); - - if (a == 0) - { - *sp = (png_byte)png_ptr->background.red; - *(sp + 1) = (png_byte)png_ptr->background.green; - *(sp + 2) = (png_byte)png_ptr->background.blue; - } - - else if (a < 0xff) - { - png_composite(*sp, *sp, a, png_ptr->background.red); - - png_composite(*(sp + 1), *(sp + 1), a, - png_ptr->background.green); - - png_composite(*(sp + 2), *(sp + 2), a, - png_ptr->background.blue); - } - } - } - } - else /* if (row_info->bit_depth == 16) */ - { -#ifdef PNG_READ_GAMMA_SUPPORTED - if (gamma_16 != NULL && gamma_16_from_1 != NULL && - gamma_16_to_1 != NULL) - { - sp = row; - for (i = 0; i < row_width; i++, sp += 8) - { - png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) - << 8) + (png_uint_16)(*(sp + 7))); - - if (a == (png_uint_16)0xffff) - { - png_uint_16 v; - - v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - - v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; - *(sp + 2) = (png_byte)((v >> 8) & 0xff); - *(sp + 3) = (png_byte)(v & 0xff); - - v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; - *(sp + 4) = (png_byte)((v >> 8) & 0xff); - *(sp + 5) = (png_byte)(v & 0xff); - } - - else if (a == 0) - { - /* Background is already in screen gamma */ - *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); - *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); - *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) - & 0xff); - *(sp + 3) = (png_byte)(png_ptr->background.green - & 0xff); - *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) - & 0xff); - *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); - } - - else - { - png_uint_16 v, w; - - v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; - png_composite_16(w, v, a, png_ptr->background_1.red); - if (optimize == 0) - w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> - 8]; - *sp = (png_byte)((w >> 8) & 0xff); - *(sp + 1) = (png_byte)(w & 0xff); - - v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; - png_composite_16(w, v, a, png_ptr->background_1.green); - if (optimize == 0) - w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> - 8]; - - *(sp + 2) = (png_byte)((w >> 8) & 0xff); - *(sp + 3) = (png_byte)(w & 0xff); - - v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; - png_composite_16(w, v, a, png_ptr->background_1.blue); - if (optimize == 0) - w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> - 8]; - - *(sp + 4) = (png_byte)((w >> 8) & 0xff); - *(sp + 5) = (png_byte)(w & 0xff); - } - } - } - - else -#endif - { - sp = row; - for (i = 0; i < row_width; i++, sp += 8) - { - png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) - << 8) + (png_uint_16)(*(sp + 7))); - - if (a == 0) - { - *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); - *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); - *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) - & 0xff); - *(sp + 3) = (png_byte)(png_ptr->background.green - & 0xff); - *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) - & 0xff); - *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); - } - - else if (a < 0xffff) - { - png_uint_16 v; - - png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); - png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) - + *(sp + 3)); - png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) - + *(sp + 5)); - - png_composite_16(v, r, a, png_ptr->background.red); - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - - png_composite_16(v, g, a, png_ptr->background.green); - *(sp + 2) = (png_byte)((v >> 8) & 0xff); - *(sp + 3) = (png_byte)(v & 0xff); - - png_composite_16(v, b, a, png_ptr->background.blue); - *(sp + 4) = (png_byte)((v >> 8) & 0xff); - *(sp + 5) = (png_byte)(v & 0xff); - } - } - } - } - break; - } - - default: - break; - } - } -} -#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ - -#ifdef PNG_READ_GAMMA_SUPPORTED -/* Gamma correct the image, avoiding the alpha channel. Make sure - * you do this after you deal with the transparency issue on grayscale - * or RGB images. If your bit depth is 8, use gamma_table, if it - * is 16, use gamma_16_table and gamma_shift. Build these with - * build_gamma_table(). - */ -static void -png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr) -{ - png_const_bytep gamma_table = png_ptr->gamma_table; - png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table; - int gamma_shift = png_ptr->gamma_shift; - - png_bytep sp; - png_uint_32 i; - png_uint_32 row_width=row_info->width; - - png_debug(1, "in png_do_gamma"); - - if (((row_info->bit_depth <= 8 && gamma_table != NULL) || - (row_info->bit_depth == 16 && gamma_16_table != NULL))) - { - switch (row_info->color_type) - { - case PNG_COLOR_TYPE_RGB: - { - if (row_info->bit_depth == 8) - { - sp = row; - for (i = 0; i < row_width; i++) - { - *sp = gamma_table[*sp]; - sp++; - *sp = gamma_table[*sp]; - sp++; - *sp = gamma_table[*sp]; - sp++; - } - } - - else /* if (row_info->bit_depth == 16) */ - { - sp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 v; - - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - sp += 2; - - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - sp += 2; - - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - sp += 2; - } - } - break; - } - - case PNG_COLOR_TYPE_RGB_ALPHA: - { - if (row_info->bit_depth == 8) - { - sp = row; - for (i = 0; i < row_width; i++) - { - *sp = gamma_table[*sp]; - sp++; - - *sp = gamma_table[*sp]; - sp++; - - *sp = gamma_table[*sp]; - sp++; - - sp++; - } - } - - else /* if (row_info->bit_depth == 16) */ - { - sp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - sp += 2; - - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - sp += 2; - - v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - sp += 4; - } - } - break; - } - - case PNG_COLOR_TYPE_GRAY_ALPHA: - { - if (row_info->bit_depth == 8) - { - sp = row; - for (i = 0; i < row_width; i++) - { - *sp = gamma_table[*sp]; - sp += 2; - } - } - - else /* if (row_info->bit_depth == 16) */ - { - sp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - sp += 4; - } - } - break; - } - - case PNG_COLOR_TYPE_GRAY: - { - if (row_info->bit_depth == 2) - { - sp = row; - for (i = 0; i < row_width; i += 4) - { - int a = *sp & 0xc0; - int b = *sp & 0x30; - int c = *sp & 0x0c; - int d = *sp & 0x03; - - *sp = (png_byte)( - ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| - ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| - ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| - ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); - sp++; - } - } - - if (row_info->bit_depth == 4) - { - sp = row; - for (i = 0; i < row_width; i += 2) - { - int msb = *sp & 0xf0; - int lsb = *sp & 0x0f; - - *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) - | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); - sp++; - } - } - - else if (row_info->bit_depth == 8) - { - sp = row; - for (i = 0; i < row_width; i++) - { - *sp = gamma_table[*sp]; - sp++; - } - } - - else if (row_info->bit_depth == 16) - { - sp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; - *sp = (png_byte)((v >> 8) & 0xff); - *(sp + 1) = (png_byte)(v & 0xff); - sp += 2; - } - } - break; - } - - default: - break; - } - } -} -#endif - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED -/* Encode the alpha channel to the output gamma (the input channel is always - * linear.) Called only with color types that have an alpha channel. Needs the - * from_1 tables. - */ -static void -png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr) -{ - png_uint_32 row_width = row_info->width; - - png_debug(1, "in png_do_encode_alpha"); - - if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) - { - if (row_info->bit_depth == 8) - { - PNG_CONST png_bytep table = png_ptr->gamma_from_1; - - if (table != NULL) - { - PNG_CONST int step = - (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2; - - /* The alpha channel is the last component: */ - row += step - 1; - - for (; row_width > 0; --row_width, row += step) - *row = table[*row]; - - return; - } - } - - else if (row_info->bit_depth == 16) - { - PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1; - PNG_CONST int gamma_shift = png_ptr->gamma_shift; - - if (table != NULL) - { - PNG_CONST int step = - (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4; - - /* The alpha channel is the last component: */ - row += step - 2; - - for (; row_width > 0; --row_width, row += step) - { - png_uint_16 v; - - v = table[*(row + 1) >> gamma_shift][*row]; - *row = (png_byte)((v >> 8) & 0xff); - *(row + 1) = (png_byte)(v & 0xff); - } - - return; - } - } - } - - /* Only get to here if called with a weird row_info; no harm has been done, - * so just issue a warning. - */ - png_warning(png_ptr, "png_do_encode_alpha: unexpected call"); -} -#endif - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* Expands a palette row to an RGB or RGBA row depending - * upon whether you supply trans and num_trans. - */ -static void -png_do_expand_palette(png_row_infop row_info, png_bytep row, - png_const_colorp palette, png_const_bytep trans_alpha, int num_trans) -{ - int shift, value; - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width=row_info->width; - - png_debug(1, "in png_do_expand_palette"); - - if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) - { - if (row_info->bit_depth < 8) - { - switch (row_info->bit_depth) - { - case 1: - { - sp = row + (png_size_t)((row_width - 1) >> 3); - dp = row + (png_size_t)row_width - 1; - shift = 7 - (int)((row_width + 7) & 0x07); - for (i = 0; i < row_width; i++) - { - if ((*sp >> shift) & 0x01) - *dp = 1; - - else - *dp = 0; - - if (shift == 7) - { - shift = 0; - sp--; - } - - else - shift++; - - dp--; - } - break; - } - - case 2: - { - sp = row + (png_size_t)((row_width - 1) >> 2); - dp = row + (png_size_t)row_width - 1; - shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); - for (i = 0; i < row_width; i++) - { - value = (*sp >> shift) & 0x03; - *dp = (png_byte)value; - if (shift == 6) - { - shift = 0; - sp--; - } - - else - shift += 2; - - dp--; - } - break; - } - - case 4: - { - sp = row + (png_size_t)((row_width - 1) >> 1); - dp = row + (png_size_t)row_width - 1; - shift = (int)((row_width & 0x01) << 2); - for (i = 0; i < row_width; i++) - { - value = (*sp >> shift) & 0x0f; - *dp = (png_byte)value; - if (shift == 4) - { - shift = 0; - sp--; - } - - else - shift += 4; - - dp--; - } - break; - } - - default: - break; - } - row_info->bit_depth = 8; - row_info->pixel_depth = 8; - row_info->rowbytes = row_width; - } - - if (row_info->bit_depth == 8) - { - { - if (num_trans > 0) - { - sp = row + (png_size_t)row_width - 1; - dp = row + (png_size_t)(row_width << 2) - 1; - - for (i = 0; i < row_width; i++) - { - if ((int)(*sp) >= num_trans) - *dp-- = 0xff; - - else - *dp-- = trans_alpha[*sp]; - - *dp-- = palette[*sp].blue; - *dp-- = palette[*sp].green; - *dp-- = palette[*sp].red; - sp--; - } - row_info->bit_depth = 8; - row_info->pixel_depth = 32; - row_info->rowbytes = row_width * 4; - row_info->color_type = 6; - row_info->channels = 4; - } - - else - { - sp = row + (png_size_t)row_width - 1; - dp = row + (png_size_t)(row_width * 3) - 1; - - for (i = 0; i < row_width; i++) - { - *dp-- = palette[*sp].blue; - *dp-- = palette[*sp].green; - *dp-- = palette[*sp].red; - sp--; - } - - row_info->bit_depth = 8; - row_info->pixel_depth = 24; - row_info->rowbytes = row_width * 3; - row_info->color_type = 2; - row_info->channels = 3; - } - } - } - } -} - -/* If the bit depth < 8, it is expanded to 8. Also, if the already - * expanded transparency value is supplied, an alpha channel is built. - */ -static void -png_do_expand(png_row_infop row_info, png_bytep row, - png_const_color_16p trans_color) -{ - int shift, value; - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width=row_info->width; - - png_debug(1, "in png_do_expand"); - - { - if (row_info->color_type == PNG_COLOR_TYPE_GRAY) - { - unsigned int gray = trans_color != NULL ? trans_color->gray : 0; - - if (row_info->bit_depth < 8) - { - switch (row_info->bit_depth) - { - case 1: - { - gray = (gray & 0x01) * 0xff; - sp = row + (png_size_t)((row_width - 1) >> 3); - dp = row + (png_size_t)row_width - 1; - shift = 7 - (int)((row_width + 7) & 0x07); - for (i = 0; i < row_width; i++) - { - if ((*sp >> shift) & 0x01) - *dp = 0xff; - - else - *dp = 0; - - if (shift == 7) - { - shift = 0; - sp--; - } - - else - shift++; - - dp--; - } - break; - } - - case 2: - { - gray = (gray & 0x03) * 0x55; - sp = row + (png_size_t)((row_width - 1) >> 2); - dp = row + (png_size_t)row_width - 1; - shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); - for (i = 0; i < row_width; i++) - { - value = (*sp >> shift) & 0x03; - *dp = (png_byte)(value | (value << 2) | (value << 4) | - (value << 6)); - if (shift == 6) - { - shift = 0; - sp--; - } - - else - shift += 2; - - dp--; - } - break; - } - - case 4: - { - gray = (gray & 0x0f) * 0x11; - sp = row + (png_size_t)((row_width - 1) >> 1); - dp = row + (png_size_t)row_width - 1; - shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); - for (i = 0; i < row_width; i++) - { - value = (*sp >> shift) & 0x0f; - *dp = (png_byte)(value | (value << 4)); - if (shift == 4) - { - shift = 0; - sp--; - } - - else - shift = 4; - - dp--; - } - break; - } - - default: - break; - } - - row_info->bit_depth = 8; - row_info->pixel_depth = 8; - row_info->rowbytes = row_width; - } - - if (trans_color != NULL) - { - if (row_info->bit_depth == 8) - { - gray = gray & 0xff; - sp = row + (png_size_t)row_width - 1; - dp = row + (png_size_t)(row_width << 1) - 1; - - for (i = 0; i < row_width; i++) - { - if ((*sp & 0xffU) == gray) - *dp-- = 0; - - else - *dp-- = 0xff; - - *dp-- = *sp--; - } - } - - else if (row_info->bit_depth == 16) - { - unsigned int gray_high = (gray >> 8) & 0xff; - unsigned int gray_low = gray & 0xff; - sp = row + row_info->rowbytes - 1; - dp = row + (row_info->rowbytes << 1) - 1; - for (i = 0; i < row_width; i++) - { - if ((*(sp - 1) & 0xffU) == gray_high && - (*(sp) & 0xffU) == gray_low) - { - *dp-- = 0; - *dp-- = 0; - } - - else - { - *dp-- = 0xff; - *dp-- = 0xff; - } - - *dp-- = *sp--; - *dp-- = *sp--; - } - } - - row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; - row_info->channels = 2; - row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, - row_width); - } - } - else if (row_info->color_type == PNG_COLOR_TYPE_RGB && - trans_color != NULL) - { - if (row_info->bit_depth == 8) - { - png_byte red = (png_byte)(trans_color->red & 0xff); - png_byte green = (png_byte)(trans_color->green & 0xff); - png_byte blue = (png_byte)(trans_color->blue & 0xff); - sp = row + (png_size_t)row_info->rowbytes - 1; - dp = row + (png_size_t)(row_width << 2) - 1; - for (i = 0; i < row_width; i++) - { - if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) - *dp-- = 0; - - else - *dp-- = 0xff; - - *dp-- = *sp--; - *dp-- = *sp--; - *dp-- = *sp--; - } - } - else if (row_info->bit_depth == 16) - { - png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff); - png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff); - png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff); - png_byte red_low = (png_byte)(trans_color->red & 0xff); - png_byte green_low = (png_byte)(trans_color->green & 0xff); - png_byte blue_low = (png_byte)(trans_color->blue & 0xff); - sp = row + row_info->rowbytes - 1; - dp = row + (png_size_t)(row_width << 3) - 1; - for (i = 0; i < row_width; i++) - { - if (*(sp - 5) == red_high && - *(sp - 4) == red_low && - *(sp - 3) == green_high && - *(sp - 2) == green_low && - *(sp - 1) == blue_high && - *(sp ) == blue_low) - { - *dp-- = 0; - *dp-- = 0; - } - - else - { - *dp-- = 0xff; - *dp-- = 0xff; - } - - *dp-- = *sp--; - *dp-- = *sp--; - *dp-- = *sp--; - *dp-- = *sp--; - *dp-- = *sp--; - *dp-- = *sp--; - } - } - row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; - row_info->channels = 4; - row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); - } - } -} -#endif - -#ifdef PNG_READ_EXPAND_16_SUPPORTED -/* If the bit depth is 8 and the color type is not a palette type expand the - * whole row to 16 bits. Has no effect otherwise. - */ -static void -png_do_expand_16(png_row_infop row_info, png_bytep row) -{ - if (row_info->bit_depth == 8 && - row_info->color_type != PNG_COLOR_TYPE_PALETTE) - { - /* The row have a sequence of bytes containing [0..255] and we need - * to turn it into another row containing [0..65535], to do this we - * calculate: - * - * (input / 255) * 65535 - * - * Which happens to be exactly input * 257 and this can be achieved - * simply by byte replication in place (copying backwards). - */ - png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */ - png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */ - while (dp > sp) - dp[-2] = dp[-1] = *--sp, dp -= 2; - - row_info->rowbytes *= 2; - row_info->bit_depth = 16; - row_info->pixel_depth = (png_byte)(row_info->channels * 16); - } -} -#endif - -#ifdef PNG_READ_QUANTIZE_SUPPORTED -static void -png_do_quantize(png_row_infop row_info, png_bytep row, - png_const_bytep palette_lookup, png_const_bytep quantize_lookup) -{ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width=row_info->width; - - png_debug(1, "in png_do_quantize"); - - if (row_info->bit_depth == 8) - { - if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup) - { - int r, g, b, p; - sp = row; - dp = row; - for (i = 0; i < row_width; i++) - { - r = *sp++; - g = *sp++; - b = *sp++; - - /* This looks real messy, but the compiler will reduce - * it down to a reasonable formula. For example, with - * 5 bits per color, we get: - * p = (((r >> 3) & 0x1f) << 10) | - * (((g >> 3) & 0x1f) << 5) | - * ((b >> 3) & 0x1f); - */ - p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & - ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << - (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | - (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & - ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << - (PNG_QUANTIZE_BLUE_BITS)) | - ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & - ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); - - *dp++ = palette_lookup[p]; - } - - row_info->color_type = PNG_COLOR_TYPE_PALETTE; - row_info->channels = 1; - row_info->pixel_depth = row_info->bit_depth; - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); - } - - else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && - palette_lookup != NULL) - { - int r, g, b, p; - sp = row; - dp = row; - for (i = 0; i < row_width; i++) - { - r = *sp++; - g = *sp++; - b = *sp++; - sp++; - - p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & - ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << - (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | - (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & - ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << - (PNG_QUANTIZE_BLUE_BITS)) | - ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & - ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); - - *dp++ = palette_lookup[p]; - } - - row_info->color_type = PNG_COLOR_TYPE_PALETTE; - row_info->channels = 1; - row_info->pixel_depth = row_info->bit_depth; - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); - } - - else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && - quantize_lookup) - { - sp = row; - - for (i = 0; i < row_width; i++, sp++) - { - *sp = quantize_lookup[*sp]; - } - } - } -} -#endif /* READ_QUANTIZE */ - -/* Transform the row. The order of transformations is significant, - * and is very touchy. If you add a transformation, take care to - * decide how it fits in with the other transformations here. - */ -void /* PRIVATE */ -png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info) -{ - png_debug(1, "in png_do_read_transformations"); - - if (png_ptr->row_buf == NULL) - { - /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this - * error is incredibly rare and incredibly easy to debug without this - * information. - */ - png_error(png_ptr, "NULL row buffer"); - } - - /* The following is debugging; prior to 1.5.4 the code was never compiled in; - * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro - * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for - * all transformations, however in practice the ROW_INIT always gets done on - * demand, if necessary. - */ - if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 && - (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) - { - /* Application has failed to call either png_read_start_image() or - * png_read_update_info() after setting transforms that expand pixels. - * This check added to libpng-1.2.19 (but not enabled until 1.5.4). - */ - png_error(png_ptr, "Uninitialized row"); - } - -#ifdef PNG_READ_EXPAND_SUPPORTED - if ((png_ptr->transformations & PNG_EXPAND) != 0) - { - if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) - { - png_do_expand_palette(row_info, png_ptr->row_buf + 1, - png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); - } - - else - { - if (png_ptr->num_trans != 0 && - (png_ptr->transformations & PNG_EXPAND_tRNS) != 0) - png_do_expand(row_info, png_ptr->row_buf + 1, - &(png_ptr->trans_color)); - - else - png_do_expand(row_info, png_ptr->row_buf + 1, - NULL); - } - } -#endif - -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && - (png_ptr->transformations & PNG_COMPOSE) == 0 && - (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) - png_do_strip_channel(row_info, png_ptr->row_buf + 1, - 0 /* at_start == false, because SWAP_ALPHA happens later */); -#endif - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED - if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) - { - int rgb_error = - png_do_rgb_to_gray(png_ptr, row_info, - png_ptr->row_buf + 1); - - if (rgb_error != 0) - { - png_ptr->rgb_to_gray_status=1; - if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == - PNG_RGB_TO_GRAY_WARN) - png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); - - if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == - PNG_RGB_TO_GRAY_ERR) - png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); - } - } -#endif - -/* From Andreas Dilger e-mail to png-implement, 26 March 1998: - * - * In most cases, the "simple transparency" should be done prior to doing - * gray-to-RGB, or you will have to test 3x as many bytes to check if a - * pixel is transparent. You would also need to make sure that the - * transparency information is upgraded to RGB. - * - * To summarize, the current flow is: - * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite - * with background "in place" if transparent, - * convert to RGB if necessary - * - Gray + alpha -> composite with gray background and remove alpha bytes, - * convert to RGB if necessary - * - * To support RGB backgrounds for gray images we need: - * - Gray + simple transparency -> convert to RGB + simple transparency, - * compare 3 or 6 bytes and composite with - * background "in place" if transparent - * (3x compare/pixel compared to doing - * composite with gray bkgrnd) - * - Gray + alpha -> convert to RGB + alpha, composite with background and - * remove alpha bytes (3x float - * operations/pixel compared with composite - * on gray background) - * - * Greg's change will do this. The reason it wasn't done before is for - * performance, as this increases the per-pixel operations. If we would check - * in advance if the background was gray or RGB, and position the gray-to-RGB - * transform appropriately, then it would save a lot of work/time. - */ - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED - /* If gray -> RGB, do so now only if background is non-gray; else do later - * for performance reasons - */ - if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 && - (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0) - png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); -#endif - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) - if ((png_ptr->transformations & PNG_COMPOSE) != 0) - png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr); -#endif - -#ifdef PNG_READ_GAMMA_SUPPORTED - if ((png_ptr->transformations & PNG_GAMMA) != 0 && -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED - /* Because RGB_TO_GRAY does the gamma transform. */ - (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 && -#endif -#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) - /* Because PNG_COMPOSE does the gamma transform if there is something to - * do (if there is an alpha channel or transparency.) - */ - !((png_ptr->transformations & PNG_COMPOSE) != 0 && - ((png_ptr->num_trans != 0) || - (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) && -#endif - /* Because png_init_read_transformations transforms the palette, unless - * RGB_TO_GRAY will do the transform. - */ - (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) - png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr); -#endif - -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && - (png_ptr->transformations & PNG_COMPOSE) != 0 && - (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) - png_do_strip_channel(row_info, png_ptr->row_buf + 1, - 0 /* at_start == false, because SWAP_ALPHA happens later */); -#endif - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 && - (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) - png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr); -#endif - -#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED - if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0) - png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED - /* There is no harm in doing both of these because only one has any effect, - * by putting the 'scale' option first if the app asks for scale (either by - * calling the API or in a TRANSFORM flag) this is what happens. - */ - if ((png_ptr->transformations & PNG_16_TO_8) != 0) - png_do_chop(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_QUANTIZE_SUPPORTED - if ((png_ptr->transformations & PNG_QUANTIZE) != 0) - { - png_do_quantize(row_info, png_ptr->row_buf + 1, - png_ptr->palette_lookup, png_ptr->quantize_index); - - if (row_info->rowbytes == 0) - png_error(png_ptr, "png_do_quantize returned rowbytes=0"); - } -#endif /* READ_QUANTIZE */ - -#ifdef PNG_READ_EXPAND_16_SUPPORTED - /* Do the expansion now, after all the arithmetic has been done. Notice - * that previous transformations can handle the PNG_EXPAND_16 flag if this - * is efficient (particularly true in the case of gamma correction, where - * better accuracy results faster!) - */ - if ((png_ptr->transformations & PNG_EXPAND_16) != 0) - png_do_expand_16(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED - /* NOTE: moved here in 1.5.4 (from much later in this list.) */ - if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 && - (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0) - png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_INVERT_SUPPORTED - if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) - png_do_invert(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) - png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_SHIFT_SUPPORTED - if ((png_ptr->transformations & PNG_SHIFT) != 0) - png_do_unshift(row_info, png_ptr->row_buf + 1, - &(png_ptr->shift)); -#endif - -#ifdef PNG_READ_PACK_SUPPORTED - if ((png_ptr->transformations & PNG_PACK) != 0) - png_do_unpack(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED - /* Added at libpng-1.5.10 */ - if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && - png_ptr->num_palette_max >= 0) - png_do_check_palette_indexes(png_ptr, row_info); -#endif - -#ifdef PNG_READ_BGR_SUPPORTED - if ((png_ptr->transformations & PNG_BGR) != 0) - png_do_bgr(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_PACKSWAP_SUPPORTED - if ((png_ptr->transformations & PNG_PACKSWAP) != 0) - png_do_packswap(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_FILLER_SUPPORTED - if ((png_ptr->transformations & PNG_FILLER) != 0) - png_do_read_filler(row_info, png_ptr->row_buf + 1, - (png_uint_32)png_ptr->filler, png_ptr->flags); -#endif - -#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0) - png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_READ_16BIT_SUPPORTED -#ifdef PNG_READ_SWAP_SUPPORTED - if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) - png_do_swap(row_info, png_ptr->row_buf + 1); -#endif -#endif - -#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED - if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) - { - if (png_ptr->read_user_transform_fn != NULL) - (*(png_ptr->read_user_transform_fn)) /* User read transform function */ - (png_ptr, /* png_ptr */ - row_info, /* row_info: */ - /* png_uint_32 width; width of row */ - /* png_size_t rowbytes; number of bytes in row */ - /* png_byte color_type; color type of pixels */ - /* png_byte bit_depth; bit depth of samples */ - /* png_byte channels; number of channels (1-4) */ - /* png_byte pixel_depth; bits per pixel (depth*channels) */ - png_ptr->row_buf + 1); /* start of pixel data for row */ -#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED - if (png_ptr->user_transform_depth != 0) - row_info->bit_depth = png_ptr->user_transform_depth; - - if (png_ptr->user_transform_channels != 0) - row_info->channels = png_ptr->user_transform_channels; -#endif - row_info->pixel_depth = (png_byte)(row_info->bit_depth * - row_info->channels); - - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width); - } -#endif -} - -#endif /* READ_TRANSFORMS */ -#endif /* READ */ diff --git a/third_party/libpng/pngrutil.c b/third_party/libpng/pngrutil.c deleted file mode 100644 index c9747fc27d..0000000000 --- a/third_party/libpng/pngrutil.c +++ /dev/null @@ -1,4529 +0,0 @@ - -/* pngrutil.c - utilities to read a PNG file - * - * Last changed in libpng 1.6.20 [December 3, 2014] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This file contains routines that are only called from within - * libpng itself during the course of reading an image. - */ - -#include "pngpriv.h" - -#ifdef PNG_READ_SUPPORTED - -png_uint_32 PNGAPI -png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf) -{ - png_uint_32 uval = png_get_uint_32(buf); - - if (uval > PNG_UINT_31_MAX) - png_error(png_ptr, "PNG unsigned integer out of range"); - - return (uval); -} - -#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED) -/* The following is a variation on the above for use with the fixed - * point values used for gAMA and cHRM. Instead of png_error it - * issues a warning and returns (-1) - an invalid value because both - * gAMA and cHRM use *unsigned* integers for fixed point values. - */ -#define PNG_FIXED_ERROR (-1) - -static png_fixed_point /* PRIVATE */ -png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf) -{ - png_uint_32 uval = png_get_uint_32(buf); - - if (uval <= PNG_UINT_31_MAX) - return (png_fixed_point)uval; /* known to be in range */ - - /* The caller can turn off the warning by passing NULL. */ - if (png_ptr != NULL) - png_warning(png_ptr, "PNG fixed point integer out of range"); - - return PNG_FIXED_ERROR; -} -#endif - -#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED -/* NOTE: the read macros will obscure these definitions, so that if - * PNG_USE_READ_MACROS is set the library will not use them internally, - * but the APIs will still be available externally. - * - * The parentheses around "PNGAPI function_name" in the following three - * functions are necessary because they allow the macros to co-exist with - * these (unused but exported) functions. - */ - -/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ -png_uint_32 (PNGAPI -png_get_uint_32)(png_const_bytep buf) -{ - png_uint_32 uval = - ((png_uint_32)(*(buf )) << 24) + - ((png_uint_32)(*(buf + 1)) << 16) + - ((png_uint_32)(*(buf + 2)) << 8) + - ((png_uint_32)(*(buf + 3)) ) ; - - return uval; -} - -/* Grab a signed 32-bit integer from a buffer in big-endian format. The - * data is stored in the PNG file in two's complement format and there - * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore - * the following code does a two's complement to native conversion. - */ -png_int_32 (PNGAPI -png_get_int_32)(png_const_bytep buf) -{ - png_uint_32 uval = png_get_uint_32(buf); - if ((uval & 0x80000000) == 0) /* non-negative */ - return uval; - - uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ - if ((uval & 0x80000000) == 0) /* no overflow */ - return -(png_int_32)uval; - /* The following has to be safe; this function only gets called on PNG data - * and if we get here that data is invalid. 0 is the most safe value and - * if not then an attacker would surely just generate a PNG with 0 instead. - */ - return 0; -} - -/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ -png_uint_16 (PNGAPI -png_get_uint_16)(png_const_bytep buf) -{ - /* ANSI-C requires an int value to accomodate at least 16 bits so this - * works and allows the compiler not to worry about possible narrowing - * on 32-bit systems. (Pre-ANSI systems did not make integers smaller - * than 16 bits either.) - */ - unsigned int val = - ((unsigned int)(*buf) << 8) + - ((unsigned int)(*(buf + 1))); - - return (png_uint_16)val; -} - -#endif /* READ_INT_FUNCTIONS */ - -/* Read and check the PNG file signature */ -void /* PRIVATE */ -png_read_sig(png_structrp png_ptr, png_inforp info_ptr) -{ - png_size_t num_checked, num_to_check; - - /* Exit if the user application does not expect a signature. */ - if (png_ptr->sig_bytes >= 8) - return; - - num_checked = png_ptr->sig_bytes; - num_to_check = 8 - num_checked; - -#ifdef PNG_IO_STATE_SUPPORTED - png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE; -#endif - - /* The signature must be serialized in a single I/O call. */ - png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); - png_ptr->sig_bytes = 8; - - if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0) - { - if (num_checked < 4 && - png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) - png_error(png_ptr, "Not a PNG file"); - else - png_error(png_ptr, "PNG file corrupted by ASCII conversion"); - } - if (num_checked < 3) - png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; -} - -/* Read the chunk header (length + type name). - * Put the type name into png_ptr->chunk_name, and return the length. - */ -png_uint_32 /* PRIVATE */ -png_read_chunk_header(png_structrp png_ptr) -{ - png_byte buf[8]; - png_uint_32 length; - -#ifdef PNG_IO_STATE_SUPPORTED - png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR; -#endif - - /* Read the length and the chunk name. - * This must be performed in a single I/O call. - */ - png_read_data(png_ptr, buf, 8); - length = png_get_uint_31(png_ptr, buf); - - /* Put the chunk name into png_ptr->chunk_name. */ - png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); - - png_debug2(0, "Reading %lx chunk, length = %lu", - (unsigned long)png_ptr->chunk_name, (unsigned long)length); - - /* Reset the crc and run it over the chunk name. */ - png_reset_crc(png_ptr); - png_calculate_crc(png_ptr, buf + 4, 4); - - /* Check to see if chunk name is valid. */ - png_check_chunk_name(png_ptr, png_ptr->chunk_name); - -#ifdef PNG_IO_STATE_SUPPORTED - png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA; -#endif - - return length; -} - -/* Read data, and (optionally) run it through the CRC. */ -void /* PRIVATE */ -png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length) -{ - if (png_ptr == NULL) - return; - - png_read_data(png_ptr, buf, length); - png_calculate_crc(png_ptr, buf, length); -} - -/* Optionally skip data and then check the CRC. Depending on whether we - * are reading an ancillary or critical chunk, and how the program has set - * things up, we may calculate the CRC on the data and print a message. - * Returns '1' if there was a CRC error, '0' otherwise. - */ -int /* PRIVATE */ -png_crc_finish(png_structrp png_ptr, png_uint_32 skip) -{ - /* The size of the local buffer for inflate is a good guess as to a - * reasonable size to use for buffering reads from the application. - */ - while (skip > 0) - { - png_uint_32 len; - png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; - - len = (sizeof tmpbuf); - if (len > skip) - len = skip; - skip -= len; - - png_crc_read(png_ptr, tmpbuf, len); - } - - if (png_crc_error(png_ptr) != 0) - { - if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0 ? - (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0 : - (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE) != 0) - { - png_chunk_warning(png_ptr, "CRC error"); - } - - else - png_chunk_error(png_ptr, "CRC error"); - - return (1); - } - - return (0); -} - -/* Compare the CRC stored in the PNG file with that calculated by libpng from - * the data it has read thus far. - */ -int /* PRIVATE */ -png_crc_error(png_structrp png_ptr) -{ - png_byte crc_bytes[4]; - png_uint_32 crc; - int need_crc = 1; - - if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0) - { - if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == - (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) - need_crc = 0; - } - - else /* critical */ - { - if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0) - need_crc = 0; - } - -#ifdef PNG_IO_STATE_SUPPORTED - png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC; -#endif - - /* The chunk CRC must be serialized in a single I/O call. */ - png_read_data(png_ptr, crc_bytes, 4); - - if (need_crc != 0) - { - crc = png_get_uint_32(crc_bytes); - return ((int)(crc != png_ptr->crc)); - } - - else - return (0); -} - -#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\ - defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\ - defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\ - defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED) -/* Manage the read buffer; this simply reallocates the buffer if it is not small - * enough (or if it is not allocated). The routine returns a pointer to the - * buffer; if an error occurs and 'warn' is set the routine returns NULL, else - * it will call png_error (via png_malloc) on failure. (warn == 2 means - * 'silent'). - */ -static png_bytep -png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn) -{ - png_bytep buffer = png_ptr->read_buffer; - - if (buffer != NULL && new_size > png_ptr->read_buffer_size) - { - png_ptr->read_buffer = NULL; - png_ptr->read_buffer = NULL; - png_ptr->read_buffer_size = 0; - png_free(png_ptr, buffer); - buffer = NULL; - } - - if (buffer == NULL) - { - buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size)); - - if (buffer != NULL) - { - png_ptr->read_buffer = buffer; - png_ptr->read_buffer_size = new_size; - } - - else if (warn < 2) /* else silent */ - { - if (warn != 0) - png_chunk_warning(png_ptr, "insufficient memory to read chunk"); - - else - png_chunk_error(png_ptr, "insufficient memory to read chunk"); - } - } - - return buffer; -} -#endif /* READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */ - -/* png_inflate_claim: claim the zstream for some nefarious purpose that involves - * decompression. Returns Z_OK on success, else a zlib error code. It checks - * the owner but, in final release builds, just issues a warning if some other - * chunk apparently owns the stream. Prior to release it does a png_error. - */ -static int -png_inflate_claim(png_structrp png_ptr, png_uint_32 owner) -{ - if (png_ptr->zowner != 0) - { - char msg[64]; - - PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner); - /* So the message that results is "<chunk> using zstream"; this is an - * internal error, but is very useful for debugging. i18n requirements - * are minimal. - */ - (void)png_safecat(msg, (sizeof msg), 4, " using zstream"); -#if PNG_RELEASE_BUILD - png_chunk_warning(png_ptr, msg); - png_ptr->zowner = 0; -#else - png_chunk_error(png_ptr, msg); -#endif - } - - /* Implementation note: unlike 'png_deflate_claim' this internal function - * does not take the size of the data as an argument. Some efficiency could - * be gained by using this when it is known *if* the zlib stream itself does - * not record the number; however, this is an illusion: the original writer - * of the PNG may have selected a lower window size, and we really must - * follow that because, for systems with with limited capabilities, we - * would otherwise reject the application's attempts to use a smaller window - * size (zlib doesn't have an interface to say "this or lower"!). - * - * inflateReset2 was added to zlib 1.2.4; before this the window could not be - * reset, therefore it is necessary to always allocate the maximum window - * size with earlier zlibs just in case later compressed chunks need it. - */ - { - int ret; /* zlib return code */ -#if PNG_ZLIB_VERNUM >= 0x1240 - -# if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW) - int window_bits; - - if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) == - PNG_OPTION_ON) - { - window_bits = 15; - png_ptr->zstream_start = 0; /* fixed window size */ - } - - else - { - window_bits = 0; - png_ptr->zstream_start = 1; - } -# else -# define window_bits 0 -# endif -#endif - - /* Set this for safety, just in case the previous owner left pointers to - * memory allocations. - */ - png_ptr->zstream.next_in = NULL; - png_ptr->zstream.avail_in = 0; - png_ptr->zstream.next_out = NULL; - png_ptr->zstream.avail_out = 0; - - if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) - { -#if PNG_ZLIB_VERNUM < 0x1240 - ret = inflateReset(&png_ptr->zstream); -#else - ret = inflateReset2(&png_ptr->zstream, window_bits); -#endif - } - - else - { -#if PNG_ZLIB_VERNUM < 0x1240 - ret = inflateInit(&png_ptr->zstream); -#else - ret = inflateInit2(&png_ptr->zstream, window_bits); -#endif - - if (ret == Z_OK) - png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; - } - - if (ret == Z_OK) - png_ptr->zowner = owner; - - else - png_zstream_error(png_ptr, ret); - - return ret; - } - -#ifdef window_bits -# undef window_bits -#endif -} - -#if PNG_ZLIB_VERNUM >= 0x1240 -/* Handle the start of the inflate stream if we called inflateInit2(strm,0); - * in this case some zlib versions skip validation of the CINFO field and, in - * certain circumstances, libpng may end up displaying an invalid image, in - * contrast to implementations that call zlib in the normal way (e.g. libpng - * 1.5). - */ -int /* PRIVATE */ -png_zlib_inflate(png_structrp png_ptr, int flush) -{ - if (png_ptr->zstream_start && png_ptr->zstream.avail_in > 0) - { - if ((*png_ptr->zstream.next_in >> 4) > 7) - { - png_ptr->zstream.msg = "invalid window size (libpng)"; - return Z_DATA_ERROR; - } - - png_ptr->zstream_start = 0; - } - - return inflate(&png_ptr->zstream, flush); -} -#endif /* Zlib >= 1.2.4 */ - -#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED -/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to - * allow the caller to do multiple calls if required. If the 'finish' flag is - * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must - * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and - * Z_OK or Z_STREAM_END will be returned on success. - * - * The input and output sizes are updated to the actual amounts of data consumed - * or written, not the amount available (as in a z_stream). The data pointers - * are not changed, so the next input is (data+input_size) and the next - * available output is (output+output_size). - */ -static int -png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish, - /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr, - /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr) -{ - if (png_ptr->zowner == owner) /* Else not claimed */ - { - int ret; - png_alloc_size_t avail_out = *output_size_ptr; - png_uint_32 avail_in = *input_size_ptr; - - /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it - * can't even necessarily handle 65536 bytes) because the type uInt is - * "16 bits or more". Consequently it is necessary to chunk the input to - * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the - * maximum value that can be stored in a uInt.) It is possible to set - * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have - * a performance advantage, because it reduces the amount of data accessed - * at each step and that may give the OS more time to page it in. - */ - png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); - /* avail_in and avail_out are set below from 'size' */ - png_ptr->zstream.avail_in = 0; - png_ptr->zstream.avail_out = 0; - - /* Read directly into the output if it is available (this is set to - * a local buffer below if output is NULL). - */ - if (output != NULL) - png_ptr->zstream.next_out = output; - - do - { - uInt avail; - Byte local_buffer[PNG_INFLATE_BUF_SIZE]; - - /* zlib INPUT BUFFER */ - /* The setting of 'avail_in' used to be outside the loop; by setting it - * inside it is possible to chunk the input to zlib and simply rely on - * zlib to advance the 'next_in' pointer. This allows arbitrary - * amounts of data to be passed through zlib at the unavoidable cost of - * requiring a window save (memcpy of up to 32768 output bytes) - * every ZLIB_IO_MAX input bytes. - */ - avail_in += png_ptr->zstream.avail_in; /* not consumed last time */ - - avail = ZLIB_IO_MAX; - - if (avail_in < avail) - avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */ - - avail_in -= avail; - png_ptr->zstream.avail_in = avail; - - /* zlib OUTPUT BUFFER */ - avail_out += png_ptr->zstream.avail_out; /* not written last time */ - - avail = ZLIB_IO_MAX; /* maximum zlib can process */ - - if (output == NULL) - { - /* Reset the output buffer each time round if output is NULL and - * make available the full buffer, up to 'remaining_space' - */ - png_ptr->zstream.next_out = local_buffer; - if ((sizeof local_buffer) < avail) - avail = (sizeof local_buffer); - } - - if (avail_out < avail) - avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */ - - png_ptr->zstream.avail_out = avail; - avail_out -= avail; - - /* zlib inflate call */ - /* In fact 'avail_out' may be 0 at this point, that happens at the end - * of the read when the final LZ end code was not passed at the end of - * the previous chunk of input data. Tell zlib if we have reached the - * end of the output buffer. - */ - ret = PNG_INFLATE(png_ptr, avail_out > 0 ? Z_NO_FLUSH : - (finish ? Z_FINISH : Z_SYNC_FLUSH)); - } while (ret == Z_OK); - - /* For safety kill the local buffer pointer now */ - if (output == NULL) - png_ptr->zstream.next_out = NULL; - - /* Claw back the 'size' and 'remaining_space' byte counts. */ - avail_in += png_ptr->zstream.avail_in; - avail_out += png_ptr->zstream.avail_out; - - /* Update the input and output sizes; the updated values are the amount - * consumed or written, effectively the inverse of what zlib uses. - */ - if (avail_out > 0) - *output_size_ptr -= avail_out; - - if (avail_in > 0) - *input_size_ptr -= avail_in; - - /* Ensure png_ptr->zstream.msg is set (even in the success case!) */ - png_zstream_error(png_ptr, ret); - return ret; - } - - else - { - /* This is a bad internal error. The recovery assigns to the zstream msg - * pointer, which is not owned by the caller, but this is safe; it's only - * used on errors! - */ - png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed"); - return Z_STREAM_ERROR; - } -} - -/* - * Decompress trailing data in a chunk. The assumption is that read_buffer - * points at an allocated area holding the contents of a chunk with a - * trailing compressed part. What we get back is an allocated area - * holding the original prefix part and an uncompressed version of the - * trailing part (the malloc area passed in is freed). - */ -static int -png_decompress_chunk(png_structrp png_ptr, - png_uint_32 chunklength, png_uint_32 prefix_size, - png_alloc_size_t *newlength /* must be initialized to the maximum! */, - int terminate /*add a '\0' to the end of the uncompressed data*/) -{ - /* TODO: implement different limits for different types of chunk. - * - * The caller supplies *newlength set to the maximum length of the - * uncompressed data, but this routine allocates space for the prefix and - * maybe a '\0' terminator too. We have to assume that 'prefix_size' is - * limited only by the maximum chunk size. - */ - png_alloc_size_t limit = PNG_SIZE_MAX; - -# ifdef PNG_SET_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_malloc_max > 0 && - png_ptr->user_chunk_malloc_max < limit) - limit = png_ptr->user_chunk_malloc_max; -# elif PNG_USER_CHUNK_MALLOC_MAX > 0 - if (PNG_USER_CHUNK_MALLOC_MAX < limit) - limit = PNG_USER_CHUNK_MALLOC_MAX; -# endif - - if (limit >= prefix_size + (terminate != 0)) - { - int ret; - - limit -= prefix_size + (terminate != 0); - - if (limit < *newlength) - *newlength = limit; - - /* Now try to claim the stream. */ - ret = png_inflate_claim(png_ptr, png_ptr->chunk_name); - - if (ret == Z_OK) - { - png_uint_32 lzsize = chunklength - prefix_size; - - ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/, - /* input: */ png_ptr->read_buffer + prefix_size, &lzsize, - /* output: */ NULL, newlength); - - if (ret == Z_STREAM_END) - { - /* Use 'inflateReset' here, not 'inflateReset2' because this - * preserves the previously decided window size (otherwise it would - * be necessary to store the previous window size.) In practice - * this doesn't matter anyway, because png_inflate will call inflate - * with Z_FINISH in almost all cases, so the window will not be - * maintained. - */ - if (inflateReset(&png_ptr->zstream) == Z_OK) - { - /* Because of the limit checks above we know that the new, - * expanded, size will fit in a size_t (let alone an - * png_alloc_size_t). Use png_malloc_base here to avoid an - * extra OOM message. - */ - png_alloc_size_t new_size = *newlength; - png_alloc_size_t buffer_size = prefix_size + new_size + - (terminate != 0); - png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr, - buffer_size)); - - if (text != NULL) - { - ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/, - png_ptr->read_buffer + prefix_size, &lzsize, - text + prefix_size, newlength); - - if (ret == Z_STREAM_END) - { - if (new_size == *newlength) - { - if (terminate != 0) - text[prefix_size + *newlength] = 0; - - if (prefix_size > 0) - memcpy(text, png_ptr->read_buffer, prefix_size); - - { - png_bytep old_ptr = png_ptr->read_buffer; - - png_ptr->read_buffer = text; - png_ptr->read_buffer_size = buffer_size; - text = old_ptr; /* freed below */ - } - } - - else - { - /* The size changed on the second read, there can be no - * guarantee that anything is correct at this point. - * The 'msg' pointer has been set to "unexpected end of - * LZ stream", which is fine, but return an error code - * that the caller won't accept. - */ - ret = PNG_UNEXPECTED_ZLIB_RETURN; - } - } - - else if (ret == Z_OK) - ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */ - - /* Free the text pointer (this is the old read_buffer on - * success) - */ - png_free(png_ptr, text); - - /* This really is very benign, but it's still an error because - * the extra space may otherwise be used as a Trojan Horse. - */ - if (ret == Z_STREAM_END && - chunklength - prefix_size != lzsize) - png_chunk_benign_error(png_ptr, "extra compressed data"); - } - - else - { - /* Out of memory allocating the buffer */ - ret = Z_MEM_ERROR; - png_zstream_error(png_ptr, Z_MEM_ERROR); - } - } - - else - { - /* inflateReset failed, store the error message */ - png_zstream_error(png_ptr, ret); - - if (ret == Z_STREAM_END) - ret = PNG_UNEXPECTED_ZLIB_RETURN; - } - } - - else if (ret == Z_OK) - ret = PNG_UNEXPECTED_ZLIB_RETURN; - - /* Release the claimed stream */ - png_ptr->zowner = 0; - } - - else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */ - ret = PNG_UNEXPECTED_ZLIB_RETURN; - - return ret; - } - - else - { - /* Application/configuration limits exceeded */ - png_zstream_error(png_ptr, Z_MEM_ERROR); - return Z_MEM_ERROR; - } -} -#endif /* READ_COMPRESSED_TEXT */ - -#ifdef PNG_READ_iCCP_SUPPORTED -/* Perform a partial read and decompress, producing 'avail_out' bytes and - * reading from the current chunk as required. - */ -static int -png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size, - png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size, - int finish) -{ - if (png_ptr->zowner == png_ptr->chunk_name) - { - int ret; - - /* next_in and avail_in must have been initialized by the caller. */ - png_ptr->zstream.next_out = next_out; - png_ptr->zstream.avail_out = 0; /* set in the loop */ - - do - { - if (png_ptr->zstream.avail_in == 0) - { - if (read_size > *chunk_bytes) - read_size = (uInt)*chunk_bytes; - *chunk_bytes -= read_size; - - if (read_size > 0) - png_crc_read(png_ptr, read_buffer, read_size); - - png_ptr->zstream.next_in = read_buffer; - png_ptr->zstream.avail_in = read_size; - } - - if (png_ptr->zstream.avail_out == 0) - { - uInt avail = ZLIB_IO_MAX; - if (avail > *out_size) - avail = (uInt)*out_size; - *out_size -= avail; - - png_ptr->zstream.avail_out = avail; - } - - /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all - * the available output is produced; this allows reading of truncated - * streams. - */ - ret = PNG_INFLATE(png_ptr, - *chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH)); - } - while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0)); - - *out_size += png_ptr->zstream.avail_out; - png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */ - - /* Ensure the error message pointer is always set: */ - png_zstream_error(png_ptr, ret); - return ret; - } - - else - { - png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed"); - return Z_STREAM_ERROR; - } -} -#endif - -/* Read and check the IDHR chunk */ - -void /* PRIVATE */ -png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_byte buf[13]; - png_uint_32 width, height; - int bit_depth, color_type, compression_type, filter_type; - int interlace_type; - - png_debug(1, "in png_handle_IHDR"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) != 0) - png_chunk_error(png_ptr, "out of place"); - - /* Check the length */ - if (length != 13) - png_chunk_error(png_ptr, "invalid"); - - png_ptr->mode |= PNG_HAVE_IHDR; - - png_crc_read(png_ptr, buf, 13); - png_crc_finish(png_ptr, 0); - - width = png_get_uint_31(png_ptr, buf); - height = png_get_uint_31(png_ptr, buf + 4); - bit_depth = buf[8]; - color_type = buf[9]; - compression_type = buf[10]; - filter_type = buf[11]; - interlace_type = buf[12]; - - /* Set internal variables */ - png_ptr->width = width; - png_ptr->height = height; - png_ptr->bit_depth = (png_byte)bit_depth; - png_ptr->interlaced = (png_byte)interlace_type; - png_ptr->color_type = (png_byte)color_type; -#ifdef PNG_MNG_FEATURES_SUPPORTED - png_ptr->filter_type = (png_byte)filter_type; -#endif - png_ptr->compression_type = (png_byte)compression_type; - - /* Find number of channels */ - switch (png_ptr->color_type) - { - default: /* invalid, png_set_IHDR calls png_error */ - case PNG_COLOR_TYPE_GRAY: - case PNG_COLOR_TYPE_PALETTE: - png_ptr->channels = 1; - break; - - case PNG_COLOR_TYPE_RGB: - png_ptr->channels = 3; - break; - - case PNG_COLOR_TYPE_GRAY_ALPHA: - png_ptr->channels = 2; - break; - - case PNG_COLOR_TYPE_RGB_ALPHA: - png_ptr->channels = 4; - break; - } - - /* Set up other useful info */ - png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels); - png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width); - png_debug1(3, "bit_depth = %d", png_ptr->bit_depth); - png_debug1(3, "channels = %d", png_ptr->channels); - png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes); - png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, - color_type, interlace_type, compression_type, filter_type); -} - -/* Read and check the palette */ -void /* PRIVATE */ -png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_color palette[PNG_MAX_PALETTE_LENGTH]; - int max_palette_length, num, i; -#ifdef PNG_POINTER_INDEXING_SUPPORTED - png_colorp pal_ptr; -#endif - - png_debug(1, "in png_handle_PLTE"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - /* Moved to before the 'after IDAT' check below because otherwise duplicate - * PLTE chunks are potentially ignored (the spec says there shall not be more - * than one PLTE, the error is not treated as benign, so this check trumps - * the requirement that PLTE appears before IDAT.) - */ - else if ((png_ptr->mode & PNG_HAVE_PLTE) != 0) - png_chunk_error(png_ptr, "duplicate"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - { - /* This is benign because the non-benign error happened before, when an - * IDAT was encountered in a color-mapped image with no PLTE. - */ - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - png_ptr->mode |= PNG_HAVE_PLTE; - - if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "ignored in grayscale PNG"); - return; - } - -#ifndef PNG_READ_OPT_PLTE_SUPPORTED - if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) - { - png_crc_finish(png_ptr, length); - return; - } -#endif - - if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3) - { - png_crc_finish(png_ptr, length); - - if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) - png_chunk_benign_error(png_ptr, "invalid"); - - else - png_chunk_error(png_ptr, "invalid"); - - return; - } - - /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */ - num = (int)length / 3; - - /* If the palette has 256 or fewer entries but is too large for the bit - * depth, we don't issue an error, to preserve the behavior of previous - * libpng versions. We silently truncate the unused extra palette entries - * here. - */ - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - max_palette_length = (1 << png_ptr->bit_depth); - else - max_palette_length = PNG_MAX_PALETTE_LENGTH; - - if (num > max_palette_length) - num = max_palette_length; - -#ifdef PNG_POINTER_INDEXING_SUPPORTED - for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) - { - png_byte buf[3]; - - png_crc_read(png_ptr, buf, 3); - pal_ptr->red = buf[0]; - pal_ptr->green = buf[1]; - pal_ptr->blue = buf[2]; - } -#else - for (i = 0; i < num; i++) - { - png_byte buf[3]; - - png_crc_read(png_ptr, buf, 3); - /* Don't depend upon png_color being any order */ - palette[i].red = buf[0]; - palette[i].green = buf[1]; - palette[i].blue = buf[2]; - } -#endif - - /* If we actually need the PLTE chunk (ie for a paletted image), we do - * whatever the normal CRC configuration tells us. However, if we - * have an RGB image, the PLTE can be considered ancillary, so - * we will act as though it is. - */ -#ifndef PNG_READ_OPT_PLTE_SUPPORTED - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) -#endif - { - png_crc_finish(png_ptr, (int) length - num * 3); - } - -#ifndef PNG_READ_OPT_PLTE_SUPPORTED - else if (png_crc_error(png_ptr) != 0) /* Only if we have a CRC error */ - { - /* If we don't want to use the data from an ancillary chunk, - * we have two options: an error abort, or a warning and we - * ignore the data in this chunk (which should be OK, since - * it's considered ancillary for a RGB or RGBA image). - * - * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the - * chunk type to determine whether to check the ancillary or the critical - * flags. - */ - if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE) == 0) - { - if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) != 0) - return; - - else - png_chunk_error(png_ptr, "CRC error"); - } - - /* Otherwise, we (optionally) emit a warning and use the chunk. */ - else if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0) - png_chunk_warning(png_ptr, "CRC error"); - } -#endif - - /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its - * own copy of the palette. This has the side effect that when png_start_row - * is called (this happens after any call to png_read_update_info) the - * info_ptr palette gets changed. This is extremely unexpected and - * confusing. - * - * Fix this by not sharing the palette in this way. - */ - png_set_PLTE(png_ptr, info_ptr, palette, num); - - /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before - * IDAT. Prior to 1.6.0 this was not checked; instead the code merely - * checked the apparent validity of a tRNS chunk inserted before PLTE on a - * palette PNG. 1.6.0 attempts to rigorously follow the standard and - * therefore does a benign error if the erroneous condition is detected *and* - * cancels the tRNS if the benign error returns. The alternative is to - * amend the standard since it would be rather hypocritical of the standards - * maintainers to ignore it. - */ -#ifdef PNG_READ_tRNS_SUPPORTED - if (png_ptr->num_trans > 0 || - (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0)) - { - /* Cancel this because otherwise it would be used if the transforms - * require it. Don't cancel the 'valid' flag because this would prevent - * detection of duplicate chunks. - */ - png_ptr->num_trans = 0; - - if (info_ptr != NULL) - info_ptr->num_trans = 0; - - png_chunk_benign_error(png_ptr, "tRNS must be after"); - } -#endif - -#ifdef PNG_READ_hIST_SUPPORTED - if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0) - png_chunk_benign_error(png_ptr, "hIST must be after"); -#endif - -#ifdef PNG_READ_bKGD_SUPPORTED - if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0) - png_chunk_benign_error(png_ptr, "bKGD must be after"); -#endif -} - -void /* PRIVATE */ -png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_debug(1, "in png_handle_IEND"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0 || - (png_ptr->mode & PNG_HAVE_IDAT) == 0) - png_chunk_error(png_ptr, "out of place"); - - png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); - - png_crc_finish(png_ptr, length); - - if (length != 0) - png_chunk_benign_error(png_ptr, "invalid"); - - PNG_UNUSED(info_ptr) -} - -#ifdef PNG_READ_gAMA_SUPPORTED -void /* PRIVATE */ -png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_fixed_point igamma; - png_byte buf[4]; - - png_debug(1, "in png_handle_gAMA"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - if (length != 4) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, buf, 4); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - igamma = png_get_fixed_point(NULL, buf); - - png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma); - png_colorspace_sync(png_ptr, info_ptr); -} -#endif - -#ifdef PNG_READ_sBIT_SUPPORTED -void /* PRIVATE */ -png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - unsigned int truelen, i; - png_byte sample_depth; - png_byte buf[4]; - - png_debug(1, "in png_handle_sBIT"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - truelen = 3; - sample_depth = 8; - } - - else - { - truelen = png_ptr->channels; - sample_depth = png_ptr->bit_depth; - } - - if (length != truelen || length > 4) - { - png_chunk_benign_error(png_ptr, "invalid"); - png_crc_finish(png_ptr, length); - return; - } - - buf[0] = buf[1] = buf[2] = buf[3] = sample_depth; - png_crc_read(png_ptr, buf, truelen); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - for (i=0; i<truelen; ++i) - { - if (buf[i] == 0 || buf[i] > sample_depth) - { - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - } - - if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) - { - png_ptr->sig_bit.red = buf[0]; - png_ptr->sig_bit.green = buf[1]; - png_ptr->sig_bit.blue = buf[2]; - png_ptr->sig_bit.alpha = buf[3]; - } - - else - { - png_ptr->sig_bit.gray = buf[0]; - png_ptr->sig_bit.red = buf[0]; - png_ptr->sig_bit.green = buf[0]; - png_ptr->sig_bit.blue = buf[0]; - png_ptr->sig_bit.alpha = buf[1]; - } - - png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); -} -#endif - -#ifdef PNG_READ_cHRM_SUPPORTED -void /* PRIVATE */ -png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_byte buf[32]; - png_xy xy; - - png_debug(1, "in png_handle_cHRM"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - if (length != 32) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, buf, 32); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - xy.whitex = png_get_fixed_point(NULL, buf); - xy.whitey = png_get_fixed_point(NULL, buf + 4); - xy.redx = png_get_fixed_point(NULL, buf + 8); - xy.redy = png_get_fixed_point(NULL, buf + 12); - xy.greenx = png_get_fixed_point(NULL, buf + 16); - xy.greeny = png_get_fixed_point(NULL, buf + 20); - xy.bluex = png_get_fixed_point(NULL, buf + 24); - xy.bluey = png_get_fixed_point(NULL, buf + 28); - - if (xy.whitex == PNG_FIXED_ERROR || - xy.whitey == PNG_FIXED_ERROR || - xy.redx == PNG_FIXED_ERROR || - xy.redy == PNG_FIXED_ERROR || - xy.greenx == PNG_FIXED_ERROR || - xy.greeny == PNG_FIXED_ERROR || - xy.bluex == PNG_FIXED_ERROR || - xy.bluey == PNG_FIXED_ERROR) - { - png_chunk_benign_error(png_ptr, "invalid values"); - return; - } - - /* If a colorspace error has already been output skip this chunk */ - if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) - return; - - if ((png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0) - { - png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; - png_colorspace_sync(png_ptr, info_ptr); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; - (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy, - 1/*prefer cHRM values*/); - png_colorspace_sync(png_ptr, info_ptr); -} -#endif - -#ifdef PNG_READ_sRGB_SUPPORTED -void /* PRIVATE */ -png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_byte intent; - - png_debug(1, "in png_handle_sRGB"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - if (length != 1) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, &intent, 1); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - /* If a colorspace error has already been output skip this chunk */ - if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) - return; - - /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect - * this. - */ - if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) != 0) - { - png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; - png_colorspace_sync(png_ptr, info_ptr); - png_chunk_benign_error(png_ptr, "too many profiles"); - return; - } - - (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent); - png_colorspace_sync(png_ptr, info_ptr); -} -#endif /* READ_sRGB */ - -#ifdef PNG_READ_iCCP_SUPPORTED -void /* PRIVATE */ -png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -/* Note: this does not properly handle profiles that are > 64K under DOS */ -{ - png_const_charp errmsg = NULL; /* error message output, or no error */ - int finished = 0; /* crc checked */ - - png_debug(1, "in png_handle_iCCP"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - /* Consistent with all the above colorspace handling an obviously *invalid* - * chunk is just ignored, so does not invalidate the color space. An - * alternative is to set the 'invalid' flags at the start of this routine - * and only clear them in they were not set before and all the tests pass. - * The minimum 'deflate' stream is assumed to be just the 2 byte header and - * 4 byte checksum. The keyword must be at least one character and there is - * a terminator (0) byte and the compression method. - */ - if (length < 9) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "too short"); - return; - } - - /* If a colorspace error has already been output skip this chunk */ - if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) - { - png_crc_finish(png_ptr, length); - return; - } - - /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect - * this. - */ - if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0) - { - uInt read_length, keyword_length; - char keyword[81]; - - /* Find the keyword; the keyword plus separator and compression method - * bytes can be at most 81 characters long. - */ - read_length = 81; /* maximum */ - if (read_length > length) - read_length = (uInt)length; - - png_crc_read(png_ptr, (png_bytep)keyword, read_length); - length -= read_length; - - keyword_length = 0; - while (keyword_length < 80 && keyword_length < read_length && - keyword[keyword_length] != 0) - ++keyword_length; - - /* TODO: make the keyword checking common */ - if (keyword_length >= 1 && keyword_length <= 79) - { - /* We only understand '0' compression - deflate - so if we get a - * different value we can't safely decode the chunk. - */ - if (keyword_length+1 < read_length && - keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE) - { - read_length -= keyword_length+2; - - if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK) - { - Byte profile_header[132]; - Byte local_buffer[PNG_INFLATE_BUF_SIZE]; - png_alloc_size_t size = (sizeof profile_header); - - png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2); - png_ptr->zstream.avail_in = read_length; - (void)png_inflate_read(png_ptr, local_buffer, - (sizeof local_buffer), &length, profile_header, &size, - 0/*finish: don't, because the output is too small*/); - - if (size == 0) - { - /* We have the ICC profile header; do the basic header checks. - */ - const png_uint_32 profile_length = - png_get_uint_32(profile_header); - - if (png_icc_check_length(png_ptr, &png_ptr->colorspace, - keyword, profile_length) != 0) - { - /* The length is apparently ok, so we can check the 132 - * byte header. - */ - if (png_icc_check_header(png_ptr, &png_ptr->colorspace, - keyword, profile_length, profile_header, - png_ptr->color_type) != 0) - { - /* Now read the tag table; a variable size buffer is - * needed at this point, allocate one for the whole - * profile. The header check has already validated - * that none of these stuff will overflow. - */ - const png_uint_32 tag_count = png_get_uint_32( - profile_header+128); - png_bytep profile = png_read_buffer(png_ptr, - profile_length, 2/*silent*/); - - if (profile != NULL) - { - memcpy(profile, profile_header, - (sizeof profile_header)); - - size = 12 * tag_count; - - (void)png_inflate_read(png_ptr, local_buffer, - (sizeof local_buffer), &length, - profile + (sizeof profile_header), &size, 0); - - /* Still expect a buffer error because we expect - * there to be some tag data! - */ - if (size == 0) - { - if (png_icc_check_tag_table(png_ptr, - &png_ptr->colorspace, keyword, profile_length, - profile) != 0) - { - /* The profile has been validated for basic - * security issues, so read the whole thing in. - */ - size = profile_length - (sizeof profile_header) - - 12 * tag_count; - - (void)png_inflate_read(png_ptr, local_buffer, - (sizeof local_buffer), &length, - profile + (sizeof profile_header) + - 12 * tag_count, &size, 1/*finish*/); - - if (length > 0 && !(png_ptr->flags & - PNG_FLAG_BENIGN_ERRORS_WARN)) - errmsg = "extra compressed data"; - - /* But otherwise allow extra data: */ - else if (size == 0) - { - if (length > 0) - { - /* This can be handled completely, so - * keep going. - */ - png_chunk_warning(png_ptr, - "extra compressed data"); - } - - png_crc_finish(png_ptr, length); - finished = 1; - -# ifdef PNG_sRGB_SUPPORTED - /* Check for a match against sRGB */ - png_icc_set_sRGB(png_ptr, - &png_ptr->colorspace, profile, - png_ptr->zstream.adler); -# endif - - /* Steal the profile for info_ptr. */ - if (info_ptr != NULL) - { - png_free_data(png_ptr, info_ptr, - PNG_FREE_ICCP, 0); - - info_ptr->iccp_name = png_voidcast(char*, - png_malloc_base(png_ptr, - keyword_length+1)); - if (info_ptr->iccp_name != NULL) - { - memcpy(info_ptr->iccp_name, keyword, - keyword_length+1); - info_ptr->iccp_proflen = - profile_length; - info_ptr->iccp_profile = profile; - png_ptr->read_buffer = NULL; /*steal*/ - info_ptr->free_me |= PNG_FREE_ICCP; - info_ptr->valid |= PNG_INFO_iCCP; - } - - else - { - png_ptr->colorspace.flags |= - PNG_COLORSPACE_INVALID; - errmsg = "out of memory"; - } - } - - /* else the profile remains in the read - * buffer which gets reused for subsequent - * chunks. - */ - - if (info_ptr != NULL) - png_colorspace_sync(png_ptr, info_ptr); - - if (errmsg == NULL) - { - png_ptr->zowner = 0; - return; - } - } - - else if (size > 0) - errmsg = "truncated"; - -#ifndef __COVERITY__ - else - errmsg = png_ptr->zstream.msg; -#endif - } - - /* else png_icc_check_tag_table output an error */ - } - - else /* profile truncated */ - errmsg = png_ptr->zstream.msg; - } - - else - errmsg = "out of memory"; - } - - /* else png_icc_check_header output an error */ - } - - /* else png_icc_check_length output an error */ - } - - else /* profile truncated */ - errmsg = png_ptr->zstream.msg; - - /* Release the stream */ - png_ptr->zowner = 0; - } - - else /* png_inflate_claim failed */ - errmsg = png_ptr->zstream.msg; - } - - else - errmsg = "bad compression method"; /* or missing */ - } - - else - errmsg = "bad keyword"; - } - - else - errmsg = "too many profiles"; - - /* Failure: the reason is in 'errmsg' */ - if (finished == 0) - png_crc_finish(png_ptr, length); - - png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; - png_colorspace_sync(png_ptr, info_ptr); - if (errmsg != NULL) /* else already output */ - png_chunk_benign_error(png_ptr, errmsg); -} -#endif /* READ_iCCP */ - -#ifdef PNG_READ_sPLT_SUPPORTED -void /* PRIVATE */ -png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -/* Note: this does not properly handle chunks that are > 64K under DOS */ -{ - png_bytep entry_start, buffer; - png_sPLT_t new_palette; - png_sPLT_entryp pp; - png_uint_32 data_length; - int entry_size, i; - png_uint_32 skip = 0; - png_uint_32 dl; - png_size_t max_dl; - - png_debug(1, "in png_handle_sPLT"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_warning(png_ptr, "No space in chunk cache for sPLT"); - png_crc_finish(png_ptr, length); - return; - } - } -#endif - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - -#ifdef PNG_MAX_MALLOC_64K - if (length > 65535U) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "too large to fit in memory"); - return; - } -#endif - - buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); - if (buffer == NULL) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of memory"); - return; - } - - - /* WARNING: this may break if size_t is less than 32 bits; it is assumed - * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a - * potential breakage point if the types in pngconf.h aren't exactly right. - */ - png_crc_read(png_ptr, buffer, length); - - if (png_crc_finish(png_ptr, skip) != 0) - return; - - buffer[length] = 0; - - for (entry_start = buffer; *entry_start; entry_start++) - /* Empty loop to find end of name */ ; - - ++entry_start; - - /* A sample depth should follow the separator, and we should be on it */ - if (length < 2U || entry_start > buffer + (length - 2U)) - { - png_warning(png_ptr, "malformed sPLT chunk"); - return; - } - - new_palette.depth = *entry_start++; - entry_size = (new_palette.depth == 8 ? 6 : 10); - /* This must fit in a png_uint_32 because it is derived from the original - * chunk data length. - */ - data_length = length - (png_uint_32)(entry_start - buffer); - - /* Integrity-check the data length */ - if ((data_length % entry_size) != 0) - { - png_warning(png_ptr, "sPLT chunk has bad length"); - return; - } - - dl = (png_int_32)(data_length / entry_size); - max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry)); - - if (dl > max_dl) - { - png_warning(png_ptr, "sPLT chunk too long"); - return; - } - - new_palette.nentries = (png_int_32)(data_length / entry_size); - - new_palette.entries = (png_sPLT_entryp)png_malloc_warn( - png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry))); - - if (new_palette.entries == NULL) - { - png_warning(png_ptr, "sPLT chunk requires too much memory"); - return; - } - -#ifdef PNG_POINTER_INDEXING_SUPPORTED - for (i = 0; i < new_palette.nentries; i++) - { - pp = new_palette.entries + i; - - if (new_palette.depth == 8) - { - pp->red = *entry_start++; - pp->green = *entry_start++; - pp->blue = *entry_start++; - pp->alpha = *entry_start++; - } - - else - { - pp->red = png_get_uint_16(entry_start); entry_start += 2; - pp->green = png_get_uint_16(entry_start); entry_start += 2; - pp->blue = png_get_uint_16(entry_start); entry_start += 2; - pp->alpha = png_get_uint_16(entry_start); entry_start += 2; - } - - pp->frequency = png_get_uint_16(entry_start); entry_start += 2; - } -#else - pp = new_palette.entries; - - for (i = 0; i < new_palette.nentries; i++) - { - - if (new_palette.depth == 8) - { - pp[i].red = *entry_start++; - pp[i].green = *entry_start++; - pp[i].blue = *entry_start++; - pp[i].alpha = *entry_start++; - } - - else - { - pp[i].red = png_get_uint_16(entry_start); entry_start += 2; - pp[i].green = png_get_uint_16(entry_start); entry_start += 2; - pp[i].blue = png_get_uint_16(entry_start); entry_start += 2; - pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; - } - - pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2; - } -#endif - - /* Discard all chunk data except the name and stash that */ - new_palette.name = (png_charp)buffer; - - png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); - - png_free(png_ptr, new_palette.entries); -} -#endif /* READ_sPLT */ - -#ifdef PNG_READ_tRNS_SUPPORTED -void /* PRIVATE */ -png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_byte readbuf[PNG_MAX_PALETTE_LENGTH]; - - png_debug(1, "in png_handle_tRNS"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) - { - png_byte buf[2]; - - if (length != 2) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, buf, 2); - png_ptr->num_trans = 1; - png_ptr->trans_color.gray = png_get_uint_16(buf); - } - - else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) - { - png_byte buf[6]; - - if (length != 6) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, buf, length); - png_ptr->num_trans = 1; - png_ptr->trans_color.red = png_get_uint_16(buf); - png_ptr->trans_color.green = png_get_uint_16(buf + 2); - png_ptr->trans_color.blue = png_get_uint_16(buf + 4); - } - - else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - if ((png_ptr->mode & PNG_HAVE_PLTE) == 0) - { - /* TODO: is this actually an error in the ISO spec? */ - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - if (length > (unsigned int) png_ptr->num_palette || - length > (unsigned int) PNG_MAX_PALETTE_LENGTH || - length == 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, readbuf, length); - png_ptr->num_trans = (png_uint_16)length; - } - - else - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid with alpha channel"); - return; - } - - if (png_crc_finish(png_ptr, 0) != 0) - { - png_ptr->num_trans = 0; - return; - } - - /* TODO: this is a horrible side effect in the palette case because the - * png_struct ends up with a pointer to the tRNS buffer owned by the - * png_info. Fix this. - */ - png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, - &(png_ptr->trans_color)); -} -#endif - -#ifdef PNG_READ_bKGD_SUPPORTED -void /* PRIVATE */ -png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - unsigned int truelen; - png_byte buf[6]; - png_color_16 background; - - png_debug(1, "in png_handle_bKGD"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 || - (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && - (png_ptr->mode & PNG_HAVE_PLTE) == 0)) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - truelen = 1; - - else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) - truelen = 6; - - else - truelen = 2; - - if (length != truelen) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, buf, truelen); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - /* We convert the index value into RGB components so that we can allow - * arbitrary RGB values for background when we have transparency, and - * so it is easy to determine the RGB values of the background color - * from the info_ptr struct. - */ - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - background.index = buf[0]; - - if (info_ptr != NULL && info_ptr->num_palette != 0) - { - if (buf[0] >= info_ptr->num_palette) - { - png_chunk_benign_error(png_ptr, "invalid index"); - return; - } - - background.red = (png_uint_16)png_ptr->palette[buf[0]].red; - background.green = (png_uint_16)png_ptr->palette[buf[0]].green; - background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; - } - - else - background.red = background.green = background.blue = 0; - - background.gray = 0; - } - - else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) /* GRAY */ - { - background.index = 0; - background.red = - background.green = - background.blue = - background.gray = png_get_uint_16(buf); - } - - else - { - background.index = 0; - background.red = png_get_uint_16(buf); - background.green = png_get_uint_16(buf + 2); - background.blue = png_get_uint_16(buf + 4); - background.gray = 0; - } - - png_set_bKGD(png_ptr, info_ptr, &background); -} -#endif - -#ifdef PNG_READ_hIST_SUPPORTED -void /* PRIVATE */ -png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - unsigned int num, i; - png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; - - png_debug(1, "in png_handle_hIST"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 || - (png_ptr->mode & PNG_HAVE_PLTE) == 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - num = length / 2 ; - - if (num != (unsigned int) png_ptr->num_palette || - num > (unsigned int) PNG_MAX_PALETTE_LENGTH) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - for (i = 0; i < num; i++) - { - png_byte buf[2]; - - png_crc_read(png_ptr, buf, 2); - readbuf[i] = png_get_uint_16(buf); - } - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - png_set_hIST(png_ptr, info_ptr, readbuf); -} -#endif - -#ifdef PNG_READ_pHYs_SUPPORTED -void /* PRIVATE */ -png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_byte buf[9]; - png_uint_32 res_x, res_y; - int unit_type; - - png_debug(1, "in png_handle_pHYs"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - if (length != 9) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, buf, 9); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - res_x = png_get_uint_32(buf); - res_y = png_get_uint_32(buf + 4); - unit_type = buf[8]; - png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); -} -#endif - -#ifdef PNG_READ_oFFs_SUPPORTED -void /* PRIVATE */ -png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_byte buf[9]; - png_int_32 offset_x, offset_y; - int unit_type; - - png_debug(1, "in png_handle_oFFs"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - if (length != 9) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, buf, 9); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - offset_x = png_get_int_32(buf); - offset_y = png_get_int_32(buf + 4); - unit_type = buf[8]; - png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); -} -#endif - -#ifdef PNG_READ_pCAL_SUPPORTED -/* Read the pCAL chunk (described in the PNG Extensions document) */ -void /* PRIVATE */ -png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_int_32 X0, X1; - png_byte type, nparams; - png_bytep buffer, buf, units, endptr; - png_charpp params; - int i; - - png_debug(1, "in png_handle_pCAL"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)", - length + 1); - - buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); - - if (buffer == NULL) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of memory"); - return; - } - - png_crc_read(png_ptr, buffer, length); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - buffer[length] = 0; /* Null terminate the last string */ - - png_debug(3, "Finding end of pCAL purpose string"); - for (buf = buffer; *buf; buf++) - /* Empty loop */ ; - - endptr = buffer + length; - - /* We need to have at least 12 bytes after the purpose string - * in order to get the parameter information. - */ - if (endptr - buf <= 12) - { - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_debug(3, "Reading pCAL X0, X1, type, nparams, and units"); - X0 = png_get_int_32((png_bytep)buf+1); - X1 = png_get_int_32((png_bytep)buf+5); - type = buf[9]; - nparams = buf[10]; - units = buf + 11; - - png_debug(3, "Checking pCAL equation type and number of parameters"); - /* Check that we have the right number of parameters for known - * equation types. - */ - if ((type == PNG_EQUATION_LINEAR && nparams != 2) || - (type == PNG_EQUATION_BASE_E && nparams != 3) || - (type == PNG_EQUATION_ARBITRARY && nparams != 3) || - (type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) - { - png_chunk_benign_error(png_ptr, "invalid parameter count"); - return; - } - - else if (type >= PNG_EQUATION_LAST) - { - png_chunk_benign_error(png_ptr, "unrecognized equation type"); - } - - for (buf = units; *buf; buf++) - /* Empty loop to move past the units string. */ ; - - png_debug(3, "Allocating pCAL parameters array"); - - params = png_voidcast(png_charpp, png_malloc_warn(png_ptr, - nparams * (sizeof (png_charp)))); - - if (params == NULL) - { - png_chunk_benign_error(png_ptr, "out of memory"); - return; - } - - /* Get pointers to the start of each parameter string. */ - for (i = 0; i < nparams; i++) - { - buf++; /* Skip the null string terminator from previous parameter. */ - - png_debug1(3, "Reading pCAL parameter %d", i); - - for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++) - /* Empty loop to move past each parameter string */ ; - - /* Make sure we haven't run out of data yet */ - if (buf > endptr) - { - png_free(png_ptr, params); - png_chunk_benign_error(png_ptr, "invalid data"); - return; - } - } - - png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams, - (png_charp)units, params); - - png_free(png_ptr, params); -} -#endif - -#ifdef PNG_READ_sCAL_SUPPORTED -/* Read the sCAL chunk */ -void /* PRIVATE */ -png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_bytep buffer; - png_size_t i; - int state; - - png_debug(1, "in png_handle_sCAL"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of place"); - return; - } - - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - /* Need unit type, width, \0, height: minimum 4 bytes */ - else if (length < 4) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)", - length + 1); - - buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); - - if (buffer == NULL) - { - png_chunk_benign_error(png_ptr, "out of memory"); - png_crc_finish(png_ptr, length); - return; - } - - png_crc_read(png_ptr, buffer, length); - buffer[length] = 0; /* Null terminate the last string */ - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - /* Validate the unit. */ - if (buffer[0] != 1 && buffer[0] != 2) - { - png_chunk_benign_error(png_ptr, "invalid unit"); - return; - } - - /* Validate the ASCII numbers, need two ASCII numbers separated by - * a '\0' and they need to fit exactly in the chunk data. - */ - i = 1; - state = 0; - - if (png_check_fp_number((png_const_charp)buffer, length, &state, &i) == 0 || - i >= length || buffer[i++] != 0) - png_chunk_benign_error(png_ptr, "bad width format"); - - else if (PNG_FP_IS_POSITIVE(state) == 0) - png_chunk_benign_error(png_ptr, "non-positive width"); - - else - { - png_size_t heighti = i; - - state = 0; - if (png_check_fp_number((png_const_charp)buffer, length, - &state, &i) == 0 || i != length) - png_chunk_benign_error(png_ptr, "bad height format"); - - else if (PNG_FP_IS_POSITIVE(state) == 0) - png_chunk_benign_error(png_ptr, "non-positive height"); - - else - /* This is the (only) success case. */ - png_set_sCAL_s(png_ptr, info_ptr, buffer[0], - (png_charp)buffer+1, (png_charp)buffer+heighti); - } -} -#endif - -#ifdef PNG_READ_tIME_SUPPORTED -void /* PRIVATE */ -png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_byte buf[7]; - png_time mod_time; - - png_debug(1, "in png_handle_tIME"); - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME) != 0) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "duplicate"); - return; - } - - if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - png_ptr->mode |= PNG_AFTER_IDAT; - - if (length != 7) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "invalid"); - return; - } - - png_crc_read(png_ptr, buf, 7); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - mod_time.second = buf[6]; - mod_time.minute = buf[5]; - mod_time.hour = buf[4]; - mod_time.day = buf[3]; - mod_time.month = buf[2]; - mod_time.year = png_get_uint_16(buf); - - png_set_tIME(png_ptr, info_ptr, &mod_time); -} -#endif - -#ifdef PNG_READ_tEXt_SUPPORTED -/* Note: this does not properly handle chunks that are > 64K under DOS */ -void /* PRIVATE */ -png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_text text_info; - png_bytep buffer; - png_charp key; - png_charp text; - png_uint_32 skip = 0; - - png_debug(1, "in png_handle_tEXt"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "no space in chunk cache"); - return; - } - } -#endif - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - png_ptr->mode |= PNG_AFTER_IDAT; - -#ifdef PNG_MAX_MALLOC_64K - if (length > 65535U) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "too large to fit in memory"); - return; - } -#endif - - buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/); - - if (buffer == NULL) - { - png_chunk_benign_error(png_ptr, "out of memory"); - return; - } - - png_crc_read(png_ptr, buffer, length); - - if (png_crc_finish(png_ptr, skip) != 0) - return; - - key = (png_charp)buffer; - key[length] = 0; - - for (text = key; *text; text++) - /* Empty loop to find end of key */ ; - - if (text != key + length) - text++; - - text_info.compression = PNG_TEXT_COMPRESSION_NONE; - text_info.key = key; - text_info.lang = NULL; - text_info.lang_key = NULL; - text_info.itxt_length = 0; - text_info.text = text; - text_info.text_length = strlen(text); - - if (png_set_text_2(png_ptr, info_ptr, &text_info, 1) != 0) - png_warning(png_ptr, "Insufficient memory to process text chunk"); -} -#endif - -#ifdef PNG_READ_zTXt_SUPPORTED -/* Note: this does not correctly handle chunks that are > 64K under DOS */ -void /* PRIVATE */ -png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_const_charp errmsg = NULL; - png_bytep buffer; - png_uint_32 keyword_length; - - png_debug(1, "in png_handle_zTXt"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "no space in chunk cache"); - return; - } - } -#endif - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - png_ptr->mode |= PNG_AFTER_IDAT; - - buffer = png_read_buffer(png_ptr, length, 2/*silent*/); - - if (buffer == NULL) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of memory"); - return; - } - - png_crc_read(png_ptr, buffer, length); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - /* TODO: also check that the keyword contents match the spec! */ - for (keyword_length = 0; - keyword_length < length && buffer[keyword_length] != 0; - ++keyword_length) - /* Empty loop to find end of name */ ; - - if (keyword_length > 79 || keyword_length < 1) - errmsg = "bad keyword"; - - /* zTXt must have some LZ data after the keyword, although it may expand to - * zero bytes; we need a '\0' at the end of the keyword, the compression type - * then the LZ data: - */ - else if (keyword_length + 3 > length) - errmsg = "truncated"; - - else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE) - errmsg = "unknown compression type"; - - else - { - png_alloc_size_t uncompressed_length = PNG_SIZE_MAX; - - /* TODO: at present png_decompress_chunk imposes a single application - * level memory limit, this should be split to different values for iCCP - * and text chunks. - */ - if (png_decompress_chunk(png_ptr, length, keyword_length+2, - &uncompressed_length, 1/*terminate*/) == Z_STREAM_END) - { - png_text text; - - /* It worked; png_ptr->read_buffer now looks like a tEXt chunk except - * for the extra compression type byte and the fact that it isn't - * necessarily '\0' terminated. - */ - buffer = png_ptr->read_buffer; - buffer[uncompressed_length+(keyword_length+2)] = 0; - - text.compression = PNG_TEXT_COMPRESSION_zTXt; - text.key = (png_charp)buffer; - text.text = (png_charp)(buffer + keyword_length+2); - text.text_length = uncompressed_length; - text.itxt_length = 0; - text.lang = NULL; - text.lang_key = NULL; - - if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0) - errmsg = "insufficient memory"; - } - - else - errmsg = png_ptr->zstream.msg; - } - - if (errmsg != NULL) - png_chunk_benign_error(png_ptr, errmsg); -} -#endif - -#ifdef PNG_READ_iTXt_SUPPORTED -/* Note: this does not correctly handle chunks that are > 64K under DOS */ -void /* PRIVATE */ -png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) -{ - png_const_charp errmsg = NULL; - png_bytep buffer; - png_uint_32 prefix_length; - - png_debug(1, "in png_handle_iTXt"); - -#ifdef PNG_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_cache_max != 0) - { - if (png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - return; - } - - if (--png_ptr->user_chunk_cache_max == 1) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "no space in chunk cache"); - return; - } - } -#endif - - if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) - png_chunk_error(png_ptr, "missing IHDR"); - - if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) - png_ptr->mode |= PNG_AFTER_IDAT; - - buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/); - - if (buffer == NULL) - { - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "out of memory"); - return; - } - - png_crc_read(png_ptr, buffer, length); - - if (png_crc_finish(png_ptr, 0) != 0) - return; - - /* First the keyword. */ - for (prefix_length=0; - prefix_length < length && buffer[prefix_length] != 0; - ++prefix_length) - /* Empty loop */ ; - - /* Perform a basic check on the keyword length here. */ - if (prefix_length > 79 || prefix_length < 1) - errmsg = "bad keyword"; - - /* Expect keyword, compression flag, compression type, language, translated - * keyword (both may be empty but are 0 terminated) then the text, which may - * be empty. - */ - else if (prefix_length + 5 > length) - errmsg = "truncated"; - - else if (buffer[prefix_length+1] == 0 || - (buffer[prefix_length+1] == 1 && - buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE)) - { - int compressed = buffer[prefix_length+1] != 0; - png_uint_32 language_offset, translated_keyword_offset; - png_alloc_size_t uncompressed_length = 0; - - /* Now the language tag */ - prefix_length += 3; - language_offset = prefix_length; - - for (; prefix_length < length && buffer[prefix_length] != 0; - ++prefix_length) - /* Empty loop */ ; - - /* WARNING: the length may be invalid here, this is checked below. */ - translated_keyword_offset = ++prefix_length; - - for (; prefix_length < length && buffer[prefix_length] != 0; - ++prefix_length) - /* Empty loop */ ; - - /* prefix_length should now be at the trailing '\0' of the translated - * keyword, but it may already be over the end. None of this arithmetic - * can overflow because chunks are at most 2^31 bytes long, but on 16-bit - * systems the available allocation may overflow. - */ - ++prefix_length; - - if (compressed == 0 && prefix_length <= length) - uncompressed_length = length - prefix_length; - - else if (compressed != 0 && prefix_length < length) - { - uncompressed_length = PNG_SIZE_MAX; - - /* TODO: at present png_decompress_chunk imposes a single application - * level memory limit, this should be split to different values for - * iCCP and text chunks. - */ - if (png_decompress_chunk(png_ptr, length, prefix_length, - &uncompressed_length, 1/*terminate*/) == Z_STREAM_END) - buffer = png_ptr->read_buffer; - - else - errmsg = png_ptr->zstream.msg; - } - - else - errmsg = "truncated"; - - if (errmsg == NULL) - { - png_text text; - - buffer[uncompressed_length+prefix_length] = 0; - - if (compressed == 0) - text.compression = PNG_ITXT_COMPRESSION_NONE; - - else - text.compression = PNG_ITXT_COMPRESSION_zTXt; - - text.key = (png_charp)buffer; - text.lang = (png_charp)buffer + language_offset; - text.lang_key = (png_charp)buffer + translated_keyword_offset; - text.text = (png_charp)buffer + prefix_length; - text.text_length = 0; - text.itxt_length = uncompressed_length; - - if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0) - errmsg = "insufficient memory"; - } - } - - else - errmsg = "bad compression info"; - - if (errmsg != NULL) - png_chunk_benign_error(png_ptr, errmsg); -} -#endif - -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED -/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */ -static int -png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length) -{ - png_alloc_size_t limit = PNG_SIZE_MAX; - - if (png_ptr->unknown_chunk.data != NULL) - { - png_free(png_ptr, png_ptr->unknown_chunk.data); - png_ptr->unknown_chunk.data = NULL; - } - -# ifdef PNG_SET_USER_LIMITS_SUPPORTED - if (png_ptr->user_chunk_malloc_max > 0 && - png_ptr->user_chunk_malloc_max < limit) - limit = png_ptr->user_chunk_malloc_max; - -# elif PNG_USER_CHUNK_MALLOC_MAX > 0 - if (PNG_USER_CHUNK_MALLOC_MAX < limit) - limit = PNG_USER_CHUNK_MALLOC_MAX; -# endif - - if (length <= limit) - { - PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name); - /* The following is safe because of the PNG_SIZE_MAX init above */ - png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/; - /* 'mode' is a flag array, only the bottom four bits matter here */ - png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/; - - if (length == 0) - png_ptr->unknown_chunk.data = NULL; - - else - { - /* Do a 'warn' here - it is handled below. */ - png_ptr->unknown_chunk.data = png_voidcast(png_bytep, - png_malloc_warn(png_ptr, length)); - } - } - - if (png_ptr->unknown_chunk.data == NULL && length > 0) - { - /* This is benign because we clean up correctly */ - png_crc_finish(png_ptr, length); - png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits"); - return 0; - } - - else - { - if (length > 0) - png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length); - png_crc_finish(png_ptr, 0); - return 1; - } -} -#endif /* READ_UNKNOWN_CHUNKS */ - -/* Handle an unknown, or known but disabled, chunk */ -void /* PRIVATE */ -png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr, - png_uint_32 length, int keep) -{ - int handled = 0; /* the chunk was handled */ - - png_debug(1, "in png_handle_unknown"); - -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing - * the bug which meant that setting a non-default behavior for a specific - * chunk would be ignored (the default was always used unless a user - * callback was installed). - * - * 'keep' is the value from the png_chunk_unknown_handling, the setting for - * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it - * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here. - * This is just an optimization to avoid multiple calls to the lookup - * function. - */ -# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED -# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED - keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name); -# endif -# endif - - /* One of the following methods will read the chunk or skip it (at least one - * of these is always defined because this is the only way to switch on - * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) - */ -# ifdef PNG_READ_USER_CHUNKS_SUPPORTED - /* The user callback takes precedence over the chunk keep value, but the - * keep value is still required to validate a save of a critical chunk. - */ - if (png_ptr->read_user_chunk_fn != NULL) - { - if (png_cache_unknown_chunk(png_ptr, length) != 0) - { - /* Callback to user unknown chunk handler */ - int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr, - &png_ptr->unknown_chunk); - - /* ret is: - * negative: An error occurred; png_chunk_error will be called. - * zero: The chunk was not handled, the chunk will be discarded - * unless png_set_keep_unknown_chunks has been used to set - * a 'keep' behavior for this particular chunk, in which - * case that will be used. A critical chunk will cause an - * error at this point unless it is to be saved. - * positive: The chunk was handled, libpng will ignore/discard it. - */ - if (ret < 0) - png_chunk_error(png_ptr, "error in user chunk"); - - else if (ret == 0) - { - /* If the keep value is 'default' or 'never' override it, but - * still error out on critical chunks unless the keep value is - * 'always' While this is weird it is the behavior in 1.4.12. - * A possible improvement would be to obey the value set for the - * chunk, but this would be an API change that would probably - * damage some applications. - * - * The png_app_warning below catches the case that matters, where - * the application has not set specific save or ignore for this - * chunk or global save or ignore. - */ - if (keep < PNG_HANDLE_CHUNK_IF_SAFE) - { -# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED - if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE) - { - png_chunk_warning(png_ptr, "Saving unknown chunk:"); - png_app_warning(png_ptr, - "forcing save of an unhandled chunk;" - " please call png_set_keep_unknown_chunks"); - /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */ - } -# endif - keep = PNG_HANDLE_CHUNK_IF_SAFE; - } - } - - else /* chunk was handled */ - { - handled = 1; - /* Critical chunks can be safely discarded at this point. */ - keep = PNG_HANDLE_CHUNK_NEVER; - } - } - - else - keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */ - } - - else - /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */ -# endif /* READ_USER_CHUNKS */ - -# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED - { - /* keep is currently just the per-chunk setting, if there was no - * setting change it to the global default now (not that this may - * still be AS_DEFAULT) then obtain the cache of the chunk if required, - * if not simply skip the chunk. - */ - if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT) - keep = png_ptr->unknown_default; - - if (keep == PNG_HANDLE_CHUNK_ALWAYS || - (keep == PNG_HANDLE_CHUNK_IF_SAFE && - PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))) - { - if (png_cache_unknown_chunk(png_ptr, length) == 0) - keep = PNG_HANDLE_CHUNK_NEVER; - } - - else - png_crc_finish(png_ptr, length); - } -# else -# ifndef PNG_READ_USER_CHUNKS_SUPPORTED -# error no method to support READ_UNKNOWN_CHUNKS -# endif - - { - /* If here there is no read callback pointer set and no support is - * compiled in to just save the unknown chunks, so simply skip this - * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then - * the app has erroneously asked for unknown chunk saving when there - * is no support. - */ - if (keep > PNG_HANDLE_CHUNK_NEVER) - png_app_error(png_ptr, "no unknown chunk support available"); - - png_crc_finish(png_ptr, length); - } -# endif - -# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED - /* Now store the chunk in the chunk list if appropriate, and if the limits - * permit it. - */ - if (keep == PNG_HANDLE_CHUNK_ALWAYS || - (keep == PNG_HANDLE_CHUNK_IF_SAFE && - PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))) - { -# ifdef PNG_USER_LIMITS_SUPPORTED - switch (png_ptr->user_chunk_cache_max) - { - case 2: - png_ptr->user_chunk_cache_max = 1; - png_chunk_benign_error(png_ptr, "no space in chunk cache"); - /* FALL THROUGH */ - case 1: - /* NOTE: prior to 1.6.0 this case resulted in an unknown critical - * chunk being skipped, now there will be a hard error below. - */ - break; - - default: /* not at limit */ - --(png_ptr->user_chunk_cache_max); - /* FALL THROUGH */ - case 0: /* no limit */ -# endif /* USER_LIMITS */ - /* Here when the limit isn't reached or when limits are compiled - * out; store the chunk. - */ - png_set_unknown_chunks(png_ptr, info_ptr, - &png_ptr->unknown_chunk, 1); - handled = 1; -# ifdef PNG_USER_LIMITS_SUPPORTED - break; - } -# endif - } -# else /* no store support: the chunk must be handled by the user callback */ - PNG_UNUSED(info_ptr) -# endif - - /* Regardless of the error handling below the cached data (if any) can be - * freed now. Notice that the data is not freed if there is a png_error, but - * it will be freed by destroy_read_struct. - */ - if (png_ptr->unknown_chunk.data != NULL) - png_free(png_ptr, png_ptr->unknown_chunk.data); - png_ptr->unknown_chunk.data = NULL; - -#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */ - /* There is no support to read an unknown chunk, so just skip it. */ - png_crc_finish(png_ptr, length); - PNG_UNUSED(info_ptr) - PNG_UNUSED(keep) -#endif /* !READ_UNKNOWN_CHUNKS */ - - /* Check for unhandled critical chunks */ - if (handled == 0 && PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) - png_chunk_error(png_ptr, "unhandled critical chunk"); -} - -/* This function is called to verify that a chunk name is valid. - * This function can't have the "critical chunk check" incorporated - * into it, since in the future we will need to be able to call user - * functions to handle unknown critical chunks after we check that - * the chunk name itself is valid. - */ - -/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is: - * - * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) - */ - -void /* PRIVATE */ -png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name) -{ - int i; - - png_debug(1, "in png_check_chunk_name"); - - for (i=1; i<=4; ++i) - { - int c = chunk_name & 0xff; - - if (c < 65 || c > 122 || (c > 90 && c < 97)) - png_chunk_error(png_ptr, "invalid chunk type"); - - chunk_name >>= 8; - } -} - -/* Combines the row recently read in with the existing pixels in the row. This - * routine takes care of alpha and transparency if requested. This routine also - * handles the two methods of progressive display of interlaced images, - * depending on the 'display' value; if 'display' is true then the whole row - * (dp) is filled from the start by replicating the available pixels. If - * 'display' is false only those pixels present in the pass are filled in. - */ -void /* PRIVATE */ -png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display) -{ - unsigned int pixel_depth = png_ptr->transformed_pixel_depth; - png_const_bytep sp = png_ptr->row_buf + 1; - png_alloc_size_t row_width = png_ptr->width; - unsigned int pass = png_ptr->pass; - png_bytep end_ptr = 0; - png_byte end_byte = 0; - unsigned int end_mask; - - png_debug(1, "in png_combine_row"); - - /* Added in 1.5.6: it should not be possible to enter this routine until at - * least one row has been read from the PNG data and transformed. - */ - if (pixel_depth == 0) - png_error(png_ptr, "internal row logic error"); - - /* Added in 1.5.4: the pixel depth should match the information returned by - * any call to png_read_update_info at this point. Do not continue if we got - * this wrong. - */ - if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes != - PNG_ROWBYTES(pixel_depth, row_width)) - png_error(png_ptr, "internal row size calculation error"); - - /* Don't expect this to ever happen: */ - if (row_width == 0) - png_error(png_ptr, "internal row width error"); - - /* Preserve the last byte in cases where only part of it will be overwritten, - * the multiply below may overflow, we don't care because ANSI-C guarantees - * we get the low bits. - */ - end_mask = (pixel_depth * row_width) & 7; - if (end_mask != 0) - { - /* end_ptr == NULL is a flag to say do nothing */ - end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1; - end_byte = *end_ptr; -# ifdef PNG_READ_PACKSWAP_SUPPORTED - if ((png_ptr->transformations & PNG_PACKSWAP) != 0) - /* little-endian byte */ - end_mask = 0xff << end_mask; - - else /* big-endian byte */ -# endif - end_mask = 0xff >> end_mask; - /* end_mask is now the bits to *keep* from the destination row */ - } - - /* For non-interlaced images this reduces to a memcpy(). A memcpy() - * will also happen if interlacing isn't supported or if the application - * does not call png_set_interlace_handling(). In the latter cases the - * caller just gets a sequence of the unexpanded rows from each interlace - * pass. - */ -#ifdef PNG_READ_INTERLACING_SUPPORTED - if (png_ptr->interlaced != 0 && - (png_ptr->transformations & PNG_INTERLACE) != 0 && - pass < 6 && (display == 0 || - /* The following copies everything for 'display' on passes 0, 2 and 4. */ - (display == 1 && (pass & 1) != 0))) - { - /* Narrow images may have no bits in a pass; the caller should handle - * this, but this test is cheap: - */ - if (row_width <= PNG_PASS_START_COL(pass)) - return; - - if (pixel_depth < 8) - { - /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit - * into 32 bits, then a single loop over the bytes using the four byte - * values in the 32-bit mask can be used. For the 'display' option the - * expanded mask may also not require any masking within a byte. To - * make this work the PACKSWAP option must be taken into account - it - * simply requires the pixels to be reversed in each byte. - * - * The 'regular' case requires a mask for each of the first 6 passes, - * the 'display' case does a copy for the even passes in the range - * 0..6. This has already been handled in the test above. - * - * The masks are arranged as four bytes with the first byte to use in - * the lowest bits (little-endian) regardless of the order (PACKSWAP or - * not) of the pixels in each byte. - * - * NOTE: the whole of this logic depends on the caller of this function - * only calling it on rows appropriate to the pass. This function only - * understands the 'x' logic; the 'y' logic is handled by the caller. - * - * The following defines allow generation of compile time constant bit - * masks for each pixel depth and each possibility of swapped or not - * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index, - * is in the range 0..7; and the result is 1 if the pixel is to be - * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B' - * for the block method. - * - * With some compilers a compile time expression of the general form: - * - * (shift >= 32) ? (a >> (shift-32)) : (b >> shift) - * - * Produces warnings with values of 'shift' in the range 33 to 63 - * because the right hand side of the ?: expression is evaluated by - * the compiler even though it isn't used. Microsoft Visual C (various - * versions) and the Intel C compiler are known to do this. To avoid - * this the following macros are used in 1.5.6. This is a temporary - * solution to avoid destabilizing the code during the release process. - */ -# if PNG_USE_COMPILE_TIME_MASKS -# define PNG_LSR(x,s) ((x)>>((s) & 0x1f)) -# define PNG_LSL(x,s) ((x)<<((s) & 0x1f)) -# else -# define PNG_LSR(x,s) ((x)>>(s)) -# define PNG_LSL(x,s) ((x)<<(s)) -# endif -# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\ - PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1) -# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\ - PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1) - - /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is - * little endian - the first pixel is at bit 0 - however the extra - * parameter 's' can be set to cause the mask position to be swapped - * within each byte, to match the PNG format. This is done by XOR of - * the shift with 7, 6 or 4 for bit depths 1, 2 and 4. - */ -# define PIXEL_MASK(p,x,d,s) \ - (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0)))) - - /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask. - */ -# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) -# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) - - /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp - * cases the result needs replicating, for the 4-bpp case the above - * generates a full 32 bits. - */ -# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1))) - -# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\ - S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\ - S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d) - -# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\ - B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\ - B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d) - -#if PNG_USE_COMPILE_TIME_MASKS - /* Utility macros to construct all the masks for a depth/swap - * combination. The 's' parameter says whether the format is PNG - * (big endian bytes) or not. Only the three odd-numbered passes are - * required for the display/block algorithm. - */ -# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\ - S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) } - -# define B_MASKS(d,s) { B_MASK(1,d,s), B_MASK(3,d,s), B_MASK(5,d,s) } - -# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2)) - - /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and - * then pass: - */ - static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = - { - /* Little-endian byte masks for PACKSWAP */ - { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) }, - /* Normal (big-endian byte) masks - PNG format */ - { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) } - }; - - /* display_mask has only three entries for the odd passes, so index by - * pass>>1. - */ - static PNG_CONST png_uint_32 display_mask[2][3][3] = - { - /* Little-endian byte masks for PACKSWAP */ - { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) }, - /* Normal (big-endian byte) masks - PNG format */ - { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) } - }; - -# define MASK(pass,depth,display,png)\ - ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\ - row_mask[png][DEPTH_INDEX(depth)][pass]) - -#else /* !PNG_USE_COMPILE_TIME_MASKS */ - /* This is the runtime alternative: it seems unlikely that this will - * ever be either smaller or faster than the compile time approach. - */ -# define MASK(pass,depth,display,png)\ - ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png)) -#endif /* !USE_COMPILE_TIME_MASKS */ - - /* Use the appropriate mask to copy the required bits. In some cases - * the byte mask will be 0 or 0xff; optimize these cases. row_width is - * the number of pixels, but the code copies bytes, so it is necessary - * to special case the end. - */ - png_uint_32 pixels_per_byte = 8 / pixel_depth; - png_uint_32 mask; - -# ifdef PNG_READ_PACKSWAP_SUPPORTED - if ((png_ptr->transformations & PNG_PACKSWAP) != 0) - mask = MASK(pass, pixel_depth, display, 0); - - else -# endif - mask = MASK(pass, pixel_depth, display, 1); - - for (;;) - { - png_uint_32 m; - - /* It doesn't matter in the following if png_uint_32 has more than - * 32 bits because the high bits always match those in m<<24; it is, - * however, essential to use OR here, not +, because of this. - */ - m = mask; - mask = (m >> 8) | (m << 24); /* rotate right to good compilers */ - m &= 0xff; - - if (m != 0) /* something to copy */ - { - if (m != 0xff) - *dp = (png_byte)((*dp & ~m) | (*sp & m)); - else - *dp = *sp; - } - - /* NOTE: this may overwrite the last byte with garbage if the image - * is not an exact number of bytes wide; libpng has always done - * this. - */ - if (row_width <= pixels_per_byte) - break; /* May need to restore part of the last byte */ - - row_width -= pixels_per_byte; - ++dp; - ++sp; - } - } - - else /* pixel_depth >= 8 */ - { - unsigned int bytes_to_copy, bytes_to_jump; - - /* Validate the depth - it must be a multiple of 8 */ - if (pixel_depth & 7) - png_error(png_ptr, "invalid user transform pixel depth"); - - pixel_depth >>= 3; /* now in bytes */ - row_width *= pixel_depth; - - /* Regardless of pass number the Adam 7 interlace always results in a - * fixed number of pixels to copy then to skip. There may be a - * different number of pixels to skip at the start though. - */ - { - unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth; - - row_width -= offset; - dp += offset; - sp += offset; - } - - /* Work out the bytes to copy. */ - if (display != 0) - { - /* When doing the 'block' algorithm the pixel in the pass gets - * replicated to adjacent pixels. This is why the even (0,2,4,6) - * passes are skipped above - the entire expanded row is copied. - */ - bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth; - - /* But don't allow this number to exceed the actual row width. */ - if (bytes_to_copy > row_width) - bytes_to_copy = (unsigned int)/*SAFE*/row_width; - } - - else /* normal row; Adam7 only ever gives us one pixel to copy. */ - bytes_to_copy = pixel_depth; - - /* In Adam7 there is a constant offset between where the pixels go. */ - bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth; - - /* And simply copy these bytes. Some optimization is possible here, - * depending on the value of 'bytes_to_copy'. Special case the low - * byte counts, which we know to be frequent. - * - * Notice that these cases all 'return' rather than 'break' - this - * avoids an unnecessary test on whether to restore the last byte - * below. - */ - switch (bytes_to_copy) - { - case 1: - for (;;) - { - *dp = *sp; - - if (row_width <= bytes_to_jump) - return; - - dp += bytes_to_jump; - sp += bytes_to_jump; - row_width -= bytes_to_jump; - } - - case 2: - /* There is a possibility of a partial copy at the end here; this - * slows the code down somewhat. - */ - do - { - dp[0] = sp[0], dp[1] = sp[1]; - - if (row_width <= bytes_to_jump) - return; - - sp += bytes_to_jump; - dp += bytes_to_jump; - row_width -= bytes_to_jump; - } - while (row_width > 1); - - /* And there can only be one byte left at this point: */ - *dp = *sp; - return; - - case 3: - /* This can only be the RGB case, so each copy is exactly one - * pixel and it is not necessary to check for a partial copy. - */ - for (;;) - { - dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2]; - - if (row_width <= bytes_to_jump) - return; - - sp += bytes_to_jump; - dp += bytes_to_jump; - row_width -= bytes_to_jump; - } - - default: -#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE - /* Check for double byte alignment and, if possible, use a - * 16-bit copy. Don't attempt this for narrow images - ones that - * are less than an interlace panel wide. Don't attempt it for - * wide bytes_to_copy either - use the memcpy there. - */ - if (bytes_to_copy < 16 /*else use memcpy*/ && - png_isaligned(dp, png_uint_16) && - png_isaligned(sp, png_uint_16) && - bytes_to_copy % (sizeof (png_uint_16)) == 0 && - bytes_to_jump % (sizeof (png_uint_16)) == 0) - { - /* Everything is aligned for png_uint_16 copies, but try for - * png_uint_32 first. - */ - if (png_isaligned(dp, png_uint_32) != 0 && - png_isaligned(sp, png_uint_32) != 0 && - bytes_to_copy % (sizeof (png_uint_32)) == 0 && - bytes_to_jump % (sizeof (png_uint_32)) == 0) - { - png_uint_32p dp32 = png_aligncast(png_uint_32p,dp); - png_const_uint_32p sp32 = png_aligncastconst( - png_const_uint_32p, sp); - size_t skip = (bytes_to_jump-bytes_to_copy) / - (sizeof (png_uint_32)); - - do - { - size_t c = bytes_to_copy; - do - { - *dp32++ = *sp32++; - c -= (sizeof (png_uint_32)); - } - while (c > 0); - - if (row_width <= bytes_to_jump) - return; - - dp32 += skip; - sp32 += skip; - row_width -= bytes_to_jump; - } - while (bytes_to_copy <= row_width); - - /* Get to here when the row_width truncates the final copy. - * There will be 1-3 bytes left to copy, so don't try the - * 16-bit loop below. - */ - dp = (png_bytep)dp32; - sp = (png_const_bytep)sp32; - do - *dp++ = *sp++; - while (--row_width > 0); - return; - } - - /* Else do it in 16-bit quantities, but only if the size is - * not too large. - */ - else - { - png_uint_16p dp16 = png_aligncast(png_uint_16p, dp); - png_const_uint_16p sp16 = png_aligncastconst( - png_const_uint_16p, sp); - size_t skip = (bytes_to_jump-bytes_to_copy) / - (sizeof (png_uint_16)); - - do - { - size_t c = bytes_to_copy; - do - { - *dp16++ = *sp16++; - c -= (sizeof (png_uint_16)); - } - while (c > 0); - - if (row_width <= bytes_to_jump) - return; - - dp16 += skip; - sp16 += skip; - row_width -= bytes_to_jump; - } - while (bytes_to_copy <= row_width); - - /* End of row - 1 byte left, bytes_to_copy > row_width: */ - dp = (png_bytep)dp16; - sp = (png_const_bytep)sp16; - do - *dp++ = *sp++; - while (--row_width > 0); - return; - } - } -#endif /* ALIGN_TYPE code */ - - /* The true default - use a memcpy: */ - for (;;) - { - memcpy(dp, sp, bytes_to_copy); - - if (row_width <= bytes_to_jump) - return; - - sp += bytes_to_jump; - dp += bytes_to_jump; - row_width -= bytes_to_jump; - if (bytes_to_copy > row_width) - bytes_to_copy = (unsigned int)/*SAFE*/row_width; - } - } - - /* NOT REACHED*/ - } /* pixel_depth >= 8 */ - - /* Here if pixel_depth < 8 to check 'end_ptr' below. */ - } - else -#endif /* READ_INTERLACING */ - - /* If here then the switch above wasn't used so just memcpy the whole row - * from the temporary row buffer (notice that this overwrites the end of the - * destination row if it is a partial byte.) - */ - memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width)); - - /* Restore the overwritten bits from the last byte if necessary. */ - if (end_ptr != NULL) - *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask)); -} - -#ifdef PNG_READ_INTERLACING_SUPPORTED -void /* PRIVATE */ -png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, - png_uint_32 transformations /* Because these may affect the byte layout */) -{ - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - /* Offset to next interlace block */ - static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - png_debug(1, "in png_do_read_interlace"); - if (row != NULL && row_info != NULL) - { - png_uint_32 final_width; - - final_width = row_info->width * png_pass_inc[pass]; - - switch (row_info->pixel_depth) - { - case 1: - { - png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3); - png_bytep dp = row + (png_size_t)((final_width - 1) >> 3); - int sshift, dshift; - int s_start, s_end, s_inc; - int jstop = png_pass_inc[pass]; - png_byte v; - png_uint_32 i; - int j; - -#ifdef PNG_READ_PACKSWAP_SUPPORTED - if ((transformations & PNG_PACKSWAP) != 0) - { - sshift = (int)((row_info->width + 7) & 0x07); - dshift = (int)((final_width + 7) & 0x07); - s_start = 7; - s_end = 0; - s_inc = -1; - } - - else -#endif - { - sshift = 7 - (int)((row_info->width + 7) & 0x07); - dshift = 7 - (int)((final_width + 7) & 0x07); - s_start = 0; - s_end = 7; - s_inc = 1; - } - - for (i = 0; i < row_info->width; i++) - { - v = (png_byte)((*sp >> sshift) & 0x01); - for (j = 0; j < jstop; j++) - { - unsigned int tmp = *dp & (0x7f7f >> (7 - dshift)); - tmp |= v << dshift; - *dp = (png_byte)(tmp & 0xff); - - if (dshift == s_end) - { - dshift = s_start; - dp--; - } - - else - dshift += s_inc; - } - - if (sshift == s_end) - { - sshift = s_start; - sp--; - } - - else - sshift += s_inc; - } - break; - } - - case 2: - { - png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); - png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); - int sshift, dshift; - int s_start, s_end, s_inc; - int jstop = png_pass_inc[pass]; - png_uint_32 i; - -#ifdef PNG_READ_PACKSWAP_SUPPORTED - if ((transformations & PNG_PACKSWAP) != 0) - { - sshift = (int)(((row_info->width + 3) & 0x03) << 1); - dshift = (int)(((final_width + 3) & 0x03) << 1); - s_start = 6; - s_end = 0; - s_inc = -2; - } - - else -#endif - { - sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1); - dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1); - s_start = 0; - s_end = 6; - s_inc = 2; - } - - for (i = 0; i < row_info->width; i++) - { - png_byte v; - int j; - - v = (png_byte)((*sp >> sshift) & 0x03); - for (j = 0; j < jstop; j++) - { - unsigned int tmp = *dp & (0x3f3f >> (6 - dshift)); - tmp |= v << dshift; - *dp = (png_byte)(tmp & 0xff); - - if (dshift == s_end) - { - dshift = s_start; - dp--; - } - - else - dshift += s_inc; - } - - if (sshift == s_end) - { - sshift = s_start; - sp--; - } - - else - sshift += s_inc; - } - break; - } - - case 4: - { - png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1); - png_bytep dp = row + (png_size_t)((final_width - 1) >> 1); - int sshift, dshift; - int s_start, s_end, s_inc; - png_uint_32 i; - int jstop = png_pass_inc[pass]; - -#ifdef PNG_READ_PACKSWAP_SUPPORTED - if ((transformations & PNG_PACKSWAP) != 0) - { - sshift = (int)(((row_info->width + 1) & 0x01) << 2); - dshift = (int)(((final_width + 1) & 0x01) << 2); - s_start = 4; - s_end = 0; - s_inc = -4; - } - - else -#endif - { - sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2); - dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2); - s_start = 0; - s_end = 4; - s_inc = 4; - } - - for (i = 0; i < row_info->width; i++) - { - png_byte v = (png_byte)((*sp >> sshift) & 0x0f); - int j; - - for (j = 0; j < jstop; j++) - { - unsigned int tmp = *dp & (0xf0f >> (4 - dshift)); - tmp |= v << dshift; - *dp = (png_byte)(tmp & 0xff); - - if (dshift == s_end) - { - dshift = s_start; - dp--; - } - - else - dshift += s_inc; - } - - if (sshift == s_end) - { - sshift = s_start; - sp--; - } - - else - sshift += s_inc; - } - break; - } - - default: - { - png_size_t pixel_bytes = (row_info->pixel_depth >> 3); - - png_bytep sp = row + (png_size_t)(row_info->width - 1) - * pixel_bytes; - - png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes; - - int jstop = png_pass_inc[pass]; - png_uint_32 i; - - for (i = 0; i < row_info->width; i++) - { - png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */ - int j; - - memcpy(v, sp, pixel_bytes); - - for (j = 0; j < jstop; j++) - { - memcpy(dp, v, pixel_bytes); - dp -= pixel_bytes; - } - - sp -= pixel_bytes; - } - break; - } - } - - row_info->width = final_width; - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); - } -#ifndef PNG_READ_PACKSWAP_SUPPORTED - PNG_UNUSED(transformations) /* Silence compiler warning */ -#endif -} -#endif /* READ_INTERLACING */ - -static void -png_read_filter_row_sub(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_size_t i; - png_size_t istop = row_info->rowbytes; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_bytep rp = row + bpp; - - PNG_UNUSED(prev_row) - - for (i = bpp; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); - rp++; - } -} - -static void -png_read_filter_row_up(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_size_t i; - png_size_t istop = row_info->rowbytes; - png_bytep rp = row; - png_const_bytep pp = prev_row; - - for (i = 0; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); - rp++; - } -} - -static void -png_read_filter_row_avg(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_size_t i; - png_bytep rp = row; - png_const_bytep pp = prev_row; - unsigned int bpp = (row_info->pixel_depth + 7) >> 3; - png_size_t istop = row_info->rowbytes - bpp; - - for (i = 0; i < bpp; i++) - { - *rp = (png_byte)(((int)(*rp) + - ((int)(*pp++) / 2 )) & 0xff); - - rp++; - } - - for (i = 0; i < istop; i++) - { - *rp = (png_byte)(((int)(*rp) + - (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); - - rp++; - } -} - -static void -png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - png_bytep rp_end = row + row_info->rowbytes; - int a, c; - - /* First pixel/byte */ - c = *prev_row++; - a = *row + c; - *row++ = (png_byte)a; - - /* Remainder */ - while (row < rp_end) - { - int b, pa, pb, pc, p; - - a &= 0xff; /* From previous iteration or start */ - b = *prev_row++; - - p = b - c; - pc = a - c; - -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif - - /* Find the best predictor, the least of pa, pb, pc favoring the earlier - * ones in the case of a tie. - */ - if (pb < pa) pa = pb, a = b; - if (pc < pa) a = c; - - /* Calculate the current pixel in a, and move the previous row pixel to c - * for the next time round the loop - */ - c = b; - a += *row; - *row++ = (png_byte)a; - } -} - -static void -png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, - png_const_bytep prev_row) -{ - int bpp = (row_info->pixel_depth + 7) >> 3; - png_bytep rp_end = row + bpp; - - /* Process the first pixel in the row completely (this is the same as 'up' - * because there is only one candidate predictor for the first row). - */ - while (row < rp_end) - { - int a = *row + *prev_row++; - *row++ = (png_byte)a; - } - - /* Remainder */ - rp_end += row_info->rowbytes - bpp; - - while (row < rp_end) - { - int a, b, c, pa, pb, pc, p; - - c = *(prev_row - bpp); - a = *(row - bpp); - b = *prev_row++; - - p = b - c; - pc = a - c; - -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif - - if (pb < pa) pa = pb, a = b; - if (pc < pa) a = c; - - a += *row; - *row++ = (png_byte)a; - } -} - -static void -png_init_filter_functions(png_structrp pp) - /* This function is called once for every PNG image (except for PNG images - * that only use PNG_FILTER_VALUE_NONE for all rows) to set the - * implementations required to reverse the filtering of PNG rows. Reversing - * the filter is the first transformation performed on the row data. It is - * performed in place, therefore an implementation can be selected based on - * the image pixel format. If the implementation depends on image width then - * take care to ensure that it works correctly if the image is interlaced - - * interlacing causes the actual row width to vary. - */ -{ - unsigned int bpp = (pp->pixel_depth + 7) >> 3; - - pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; - pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; - pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; - if (bpp == 1) - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth_1byte_pixel; - else - pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = - png_read_filter_row_paeth_multibyte_pixel; - -#ifdef PNG_FILTER_OPTIMIZATIONS - /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to - * call to install hardware optimizations for the above functions; simply - * replace whatever elements of the pp->read_filter[] array with a hardware - * specific (or, for that matter, generic) optimization. - * - * To see an example of this examine what configure.ac does when - * --enable-arm-neon is specified on the command line. - */ - PNG_FILTER_OPTIMIZATIONS(pp, bpp); -#endif -} - -void /* PRIVATE */ -png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row, - png_const_bytep prev_row, int filter) -{ - /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define - * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic - * implementations. See png_init_filter_functions above. - */ - if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) - { - if (pp->read_filter[0] == NULL) - png_init_filter_functions(pp); - - pp->read_filter[filter-1](row_info, row, prev_row); - } -} - -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED -void /* PRIVATE */ -png_read_IDAT_data(png_structrp png_ptr, png_bytep output, - png_alloc_size_t avail_out) -{ - /* Loop reading IDATs and decompressing the result into output[avail_out] */ - png_ptr->zstream.next_out = output; - png_ptr->zstream.avail_out = 0; /* safety: set below */ - - if (output == NULL) - avail_out = 0; - - do - { - int ret; - png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; - - if (png_ptr->zstream.avail_in == 0) - { - uInt avail_in; - png_bytep buffer; - - while (png_ptr->idat_size == 0) - { - png_crc_finish(png_ptr, 0); - - png_ptr->idat_size = png_read_chunk_header(png_ptr); - /* This is an error even in the 'check' case because the code just - * consumed a non-IDAT header. - */ - if (png_ptr->chunk_name != png_IDAT) - png_error(png_ptr, "Not enough image data"); - } - - avail_in = png_ptr->IDAT_read_size; - - if (avail_in > png_ptr->idat_size) - avail_in = (uInt)png_ptr->idat_size; - - /* A PNG with a gradually increasing IDAT size will defeat this attempt - * to minimize memory usage by causing lots of re-allocs, but - * realistically doing IDAT_read_size re-allocs is not likely to be a - * big problem. - */ - buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/); - - png_crc_read(png_ptr, buffer, avail_in); - png_ptr->idat_size -= avail_in; - - png_ptr->zstream.next_in = buffer; - png_ptr->zstream.avail_in = avail_in; - } - - /* And set up the output side. */ - if (output != NULL) /* standard read */ - { - uInt out = ZLIB_IO_MAX; - - if (out > avail_out) - out = (uInt)avail_out; - - avail_out -= out; - png_ptr->zstream.avail_out = out; - } - - else /* after last row, checking for end */ - { - png_ptr->zstream.next_out = tmpbuf; - png_ptr->zstream.avail_out = (sizeof tmpbuf); - } - - /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the - * process. If the LZ stream is truncated the sequential reader will - * terminally damage the stream, above, by reading the chunk header of the - * following chunk (it then exits with png_error). - * - * TODO: deal more elegantly with truncated IDAT lists. - */ - ret = PNG_INFLATE(png_ptr, Z_NO_FLUSH); - - /* Take the unconsumed output back. */ - if (output != NULL) - avail_out += png_ptr->zstream.avail_out; - - else /* avail_out counts the extra bytes */ - avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out; - - png_ptr->zstream.avail_out = 0; - - if (ret == Z_STREAM_END) - { - /* Do this for safety; we won't read any more into this row. */ - png_ptr->zstream.next_out = NULL; - - png_ptr->mode |= PNG_AFTER_IDAT; - png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; - - if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0) - png_chunk_benign_error(png_ptr, "Extra compressed data"); - break; - } - - if (ret != Z_OK) - { - png_zstream_error(png_ptr, ret); - - if (output != NULL) - png_chunk_error(png_ptr, png_ptr->zstream.msg); - - else /* checking */ - { - png_chunk_benign_error(png_ptr, png_ptr->zstream.msg); - return; - } - } - } while (avail_out > 0); - - if (avail_out > 0) - { - /* The stream ended before the image; this is the same as too few IDATs so - * should be handled the same way. - */ - if (output != NULL) - png_error(png_ptr, "Not enough image data"); - - else /* the deflate stream contained extra data */ - png_chunk_benign_error(png_ptr, "Too much image data"); - } -} - -void /* PRIVATE */ -png_read_finish_IDAT(png_structrp png_ptr) -{ - /* We don't need any more data and the stream should have ended, however the - * LZ end code may actually not have been processed. In this case we must - * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk - * may still remain to be consumed. - */ - if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) - { - /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in - * the compressed stream, but the stream may be damaged too, so even after - * this call we may need to terminate the zstream ownership. - */ - png_read_IDAT_data(png_ptr, NULL, 0); - png_ptr->zstream.next_out = NULL; /* safety */ - - /* Now clear everything out for safety; the following may not have been - * done. - */ - if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) - { - png_ptr->mode |= PNG_AFTER_IDAT; - png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; - } - } - - /* If the zstream has not been released do it now *and* terminate the reading - * of the final IDAT chunk. - */ - if (png_ptr->zowner == png_IDAT) - { - /* Always do this; the pointers otherwise point into the read buffer. */ - png_ptr->zstream.next_in = NULL; - png_ptr->zstream.avail_in = 0; - - /* Now we no longer own the zstream. */ - png_ptr->zowner = 0; - - /* The slightly weird semantics of the sequential IDAT reading is that we - * are always in or at the end of an IDAT chunk, so we always need to do a - * crc_finish here. If idat_size is non-zero we also need to read the - * spurious bytes at the end of the chunk now. - */ - (void)png_crc_finish(png_ptr, png_ptr->idat_size); - } -} - -void /* PRIVATE */ -png_read_finish_row(png_structrp png_ptr) -{ - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; - - png_debug(1, "in png_read_finish_row"); - png_ptr->row_number++; - if (png_ptr->row_number < png_ptr->num_rows) - return; - - if (png_ptr->interlaced != 0) - { - png_ptr->row_number = 0; - - /* TO DO: don't do this if prev_row isn't needed (requires - * read-ahead of the next row's filter byte. - */ - memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); - - do - { - png_ptr->pass++; - - if (png_ptr->pass >= 7) - break; - - png_ptr->iwidth = (png_ptr->width + - png_pass_inc[png_ptr->pass] - 1 - - png_pass_start[png_ptr->pass]) / - png_pass_inc[png_ptr->pass]; - - if ((png_ptr->transformations & PNG_INTERLACE) == 0) - { - png_ptr->num_rows = (png_ptr->height + - png_pass_yinc[png_ptr->pass] - 1 - - png_pass_ystart[png_ptr->pass]) / - png_pass_yinc[png_ptr->pass]; - } - - else /* if (png_ptr->transformations & PNG_INTERLACE) */ - break; /* libpng deinterlacing sees every row */ - - } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0); - - if (png_ptr->pass < 7) - return; - } - - /* Here after at the end of the last row of the last pass. */ - png_read_finish_IDAT(png_ptr); -} -#endif /* SEQUENTIAL_READ */ - -void /* PRIVATE */ -png_read_start_row(png_structrp png_ptr) -{ - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; - - int max_pixel_depth; - png_size_t row_bytes; - - png_debug(1, "in png_read_start_row"); - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - png_init_read_transformations(png_ptr); -#endif - if (png_ptr->interlaced != 0) - { - if ((png_ptr->transformations & PNG_INTERLACE) == 0) - png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - - png_pass_ystart[0]) / png_pass_yinc[0]; - - else - png_ptr->num_rows = png_ptr->height; - - png_ptr->iwidth = (png_ptr->width + - png_pass_inc[png_ptr->pass] - 1 - - png_pass_start[png_ptr->pass]) / - png_pass_inc[png_ptr->pass]; - } - - else - { - png_ptr->num_rows = png_ptr->height; - png_ptr->iwidth = png_ptr->width; - } - - max_pixel_depth = png_ptr->pixel_depth; - - /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpler set of - * calculations to calculate the final pixel depth, then - * png_do_read_transforms actually does the transforms. This means that the - * code which effectively calculates this value is actually repeated in three - * separate places. They must all match. Innocent changes to the order of - * transformations can and will break libpng in a way that causes memory - * overwrites. - * - * TODO: fix this. - */ -#ifdef PNG_READ_PACK_SUPPORTED - if ((png_ptr->transformations & PNG_PACK) != 0 && png_ptr->bit_depth < 8) - max_pixel_depth = 8; -#endif - -#ifdef PNG_READ_EXPAND_SUPPORTED - if ((png_ptr->transformations & PNG_EXPAND) != 0) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - if (png_ptr->num_trans != 0) - max_pixel_depth = 32; - - else - max_pixel_depth = 24; - } - - else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) - { - if (max_pixel_depth < 8) - max_pixel_depth = 8; - - if (png_ptr->num_trans != 0) - max_pixel_depth *= 2; - } - - else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) - { - if (png_ptr->num_trans != 0) - { - max_pixel_depth *= 4; - max_pixel_depth /= 3; - } - } - } -#endif - -#ifdef PNG_READ_EXPAND_16_SUPPORTED - if ((png_ptr->transformations & PNG_EXPAND_16) != 0) - { -# ifdef PNG_READ_EXPAND_SUPPORTED - /* In fact it is an error if it isn't supported, but checking is - * the safe way. - */ - if ((png_ptr->transformations & PNG_EXPAND) != 0) - { - if (png_ptr->bit_depth < 16) - max_pixel_depth *= 2; - } - else -# endif - png_ptr->transformations &= ~PNG_EXPAND_16; - } -#endif - -#ifdef PNG_READ_FILLER_SUPPORTED - if ((png_ptr->transformations & (PNG_FILLER)) != 0) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) - { - if (max_pixel_depth <= 8) - max_pixel_depth = 16; - - else - max_pixel_depth = 32; - } - - else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB || - png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - if (max_pixel_depth <= 32) - max_pixel_depth = 32; - - else - max_pixel_depth = 64; - } - } -#endif - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED - if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) - { - if ( -#ifdef PNG_READ_EXPAND_SUPPORTED - (png_ptr->num_trans != 0 && - (png_ptr->transformations & PNG_EXPAND) != 0) || -#endif -#ifdef PNG_READ_FILLER_SUPPORTED - (png_ptr->transformations & (PNG_FILLER)) != 0 || -#endif - png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - { - if (max_pixel_depth <= 16) - max_pixel_depth = 32; - - else - max_pixel_depth = 64; - } - - else - { - if (max_pixel_depth <= 8) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - max_pixel_depth = 32; - - else - max_pixel_depth = 24; - } - - else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - max_pixel_depth = 64; - - else - max_pixel_depth = 48; - } - } -#endif - -#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \ -defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) - if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) - { - int user_pixel_depth = png_ptr->user_transform_depth * - png_ptr->user_transform_channels; - - if (user_pixel_depth > max_pixel_depth) - max_pixel_depth = user_pixel_depth; - } -#endif - - /* This value is stored in png_struct and double checked in the row read - * code. - */ - png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth; - png_ptr->transformed_pixel_depth = 0; /* calculated on demand */ - - /* Align the width on the next larger 8 pixels. Mainly used - * for interlacing - */ - row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); - /* Calculate the maximum bytes needed, adding a byte and a pixel - * for safety's sake - */ - row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) + - 1 + ((max_pixel_depth + 7) >> 3); - -#ifdef PNG_MAX_MALLOC_64K - if (row_bytes > (png_uint_32)65536L) - png_error(png_ptr, "This image requires a row greater than 64KB"); -#endif - - if (row_bytes + 48 > png_ptr->old_big_row_buf_size) - { - png_free(png_ptr, png_ptr->big_row_buf); - png_free(png_ptr, png_ptr->big_prev_row); - - if (png_ptr->interlaced != 0) - png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, - row_bytes + 48); - - else - png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48); - - png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48); - -#ifdef PNG_ALIGNED_MEMORY_SUPPORTED - /* Use 16-byte aligned memory for row_buf with at least 16 bytes - * of padding before and after row_buf; treat prev_row similarly. - * NOTE: the alignment is to the start of the pixels, one beyond the start - * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this - * was incorrect; the filter byte was aligned, which had the exact - * opposite effect of that intended. - */ - { - png_bytep temp = png_ptr->big_row_buf + 32; - int extra = (int)((temp - (png_bytep)0) & 0x0f); - png_ptr->row_buf = temp - extra - 1/*filter byte*/; - - temp = png_ptr->big_prev_row + 32; - extra = (int)((temp - (png_bytep)0) & 0x0f); - png_ptr->prev_row = temp - extra - 1/*filter byte*/; - } - -#else - /* Use 31 bytes of padding before and 17 bytes after row_buf. */ - png_ptr->row_buf = png_ptr->big_row_buf + 31; - png_ptr->prev_row = png_ptr->big_prev_row + 31; -#endif - png_ptr->old_big_row_buf_size = row_bytes + 48; - } - -#ifdef PNG_MAX_MALLOC_64K - if (png_ptr->rowbytes > 65535) - png_error(png_ptr, "This image requires a row greater than 64KB"); - -#endif - if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) - png_error(png_ptr, "Row has too many bytes to allocate in memory"); - - memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); - - png_debug1(3, "width = %u,", png_ptr->width); - png_debug1(3, "height = %u,", png_ptr->height); - png_debug1(3, "iwidth = %u,", png_ptr->iwidth); - png_debug1(3, "num_rows = %u,", png_ptr->num_rows); - png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes); - png_debug1(3, "irowbytes = %lu", - (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1); - - /* The sequential reader needs a buffer for IDAT, but the progressive reader - * does not, so free the read buffer now regardless; the sequential reader - * reallocates it on demand. - */ - if (png_ptr->read_buffer != 0) - { - png_bytep buffer = png_ptr->read_buffer; - - png_ptr->read_buffer_size = 0; - png_ptr->read_buffer = NULL; - png_free(png_ptr, buffer); - } - - /* Finally claim the zstream for the inflate of the IDAT data, use the bits - * value from the stream (note that this will result in a fatal error if the - * IDAT stream has a bogus deflate header window_bits value, but this should - * not be happening any longer!) - */ - if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - - png_ptr->flags |= PNG_FLAG_ROW_INIT; -} -#endif /* READ */ diff --git a/third_party/libpng/pngset.c b/third_party/libpng/pngset.c deleted file mode 100644 index 4bd5ab3cba..0000000000 --- a/third_party/libpng/pngset.c +++ /dev/null @@ -1,1731 +0,0 @@ - -/* pngset.c - storage of image information into info struct - * - * Last changed in libpng 1.6.21 [January 15, 2016] - * Copyright (c) 1998-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * The functions here are used during reads to store data from the file - * into the info struct, and during writes to store application data - * into the info struct for writing into the file. This abstracts the - * info struct and allows us to change the structure in the future. - */ - -#include "pngpriv.h" - -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) - -#ifdef PNG_bKGD_SUPPORTED -void PNGAPI -png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr, - png_const_color_16p background) -{ - png_debug1(1, "in %s storage function", "bKGD"); - - if (png_ptr == NULL || info_ptr == NULL || background == NULL) - return; - - info_ptr->background = *background; - info_ptr->valid |= PNG_INFO_bKGD; -} -#endif - -#ifdef PNG_cHRM_SUPPORTED -void PNGFAPI -png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr, - png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x, - png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y, - png_fixed_point blue_x, png_fixed_point blue_y) -{ - png_xy xy; - - png_debug1(1, "in %s storage function", "cHRM fixed"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - xy.redx = red_x; - xy.redy = red_y; - xy.greenx = green_x; - xy.greeny = green_y; - xy.bluex = blue_x; - xy.bluey = blue_y; - xy.whitex = white_x; - xy.whitey = white_y; - - if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy, - 2/* override with app values*/) != 0) - info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; - - png_colorspace_sync_info(png_ptr, info_ptr); -} - -void PNGFAPI -png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr, - png_fixed_point int_red_X, png_fixed_point int_red_Y, - png_fixed_point int_red_Z, png_fixed_point int_green_X, - png_fixed_point int_green_Y, png_fixed_point int_green_Z, - png_fixed_point int_blue_X, png_fixed_point int_blue_Y, - png_fixed_point int_blue_Z) -{ - png_XYZ XYZ; - - png_debug1(1, "in %s storage function", "cHRM XYZ fixed"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - XYZ.red_X = int_red_X; - XYZ.red_Y = int_red_Y; - XYZ.red_Z = int_red_Z; - XYZ.green_X = int_green_X; - XYZ.green_Y = int_green_Y; - XYZ.green_Z = int_green_Z; - XYZ.blue_X = int_blue_X; - XYZ.blue_Y = int_blue_Y; - XYZ.blue_Z = int_blue_Z; - - if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace, - &XYZ, 2) != 0) - info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; - - png_colorspace_sync_info(png_ptr, info_ptr); -} - -# ifdef PNG_FLOATING_POINT_SUPPORTED -void PNGAPI -png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr, - double white_x, double white_y, double red_x, double red_y, - double green_x, double green_y, double blue_x, double blue_y) -{ - png_set_cHRM_fixed(png_ptr, info_ptr, - png_fixed(png_ptr, white_x, "cHRM White X"), - png_fixed(png_ptr, white_y, "cHRM White Y"), - png_fixed(png_ptr, red_x, "cHRM Red X"), - png_fixed(png_ptr, red_y, "cHRM Red Y"), - png_fixed(png_ptr, green_x, "cHRM Green X"), - png_fixed(png_ptr, green_y, "cHRM Green Y"), - png_fixed(png_ptr, blue_x, "cHRM Blue X"), - png_fixed(png_ptr, blue_y, "cHRM Blue Y")); -} - -void PNGAPI -png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X, - double red_Y, double red_Z, double green_X, double green_Y, double green_Z, - double blue_X, double blue_Y, double blue_Z) -{ - png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, - png_fixed(png_ptr, red_X, "cHRM Red X"), - png_fixed(png_ptr, red_Y, "cHRM Red Y"), - png_fixed(png_ptr, red_Z, "cHRM Red Z"), - png_fixed(png_ptr, green_X, "cHRM Green X"), - png_fixed(png_ptr, green_Y, "cHRM Green Y"), - png_fixed(png_ptr, green_Z, "cHRM Green Z"), - png_fixed(png_ptr, blue_X, "cHRM Blue X"), - png_fixed(png_ptr, blue_Y, "cHRM Blue Y"), - png_fixed(png_ptr, blue_Z, "cHRM Blue Z")); -} -# endif /* FLOATING_POINT */ - -#endif /* cHRM */ - -#ifdef PNG_gAMA_SUPPORTED -void PNGFAPI -png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr, - png_fixed_point file_gamma) -{ - png_debug1(1, "in %s storage function", "gAMA"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma); - png_colorspace_sync_info(png_ptr, info_ptr); -} - -# ifdef PNG_FLOATING_POINT_SUPPORTED -void PNGAPI -png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma) -{ - png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma, - "png_set_gAMA")); -} -# endif -#endif - -#ifdef PNG_hIST_SUPPORTED -void PNGAPI -png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr, - png_const_uint_16p hist) -{ - int i; - - png_debug1(1, "in %s storage function", "hIST"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - if (info_ptr->num_palette == 0 || info_ptr->num_palette - > PNG_MAX_PALETTE_LENGTH) - { - png_warning(png_ptr, - "Invalid palette size, hIST allocation skipped"); - - return; - } - - png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0); - - /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in - * version 1.2.1 - */ - info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr, - PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16)))); - - if (info_ptr->hist == NULL) - { - png_warning(png_ptr, "Insufficient memory for hIST chunk data"); - - return; - } - - info_ptr->free_me |= PNG_FREE_HIST; - - for (i = 0; i < info_ptr->num_palette; i++) - info_ptr->hist[i] = hist[i]; - - info_ptr->valid |= PNG_INFO_hIST; -} -#endif - -void PNGAPI -png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr, - png_uint_32 width, png_uint_32 height, int bit_depth, - int color_type, int interlace_type, int compression_type, - int filter_type) -{ - png_debug1(1, "in %s storage function", "IHDR"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - info_ptr->width = width; - info_ptr->height = height; - info_ptr->bit_depth = (png_byte)bit_depth; - info_ptr->color_type = (png_byte)color_type; - info_ptr->compression_type = (png_byte)compression_type; - info_ptr->filter_type = (png_byte)filter_type; - info_ptr->interlace_type = (png_byte)interlace_type; - - png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height, - info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type, - info_ptr->compression_type, info_ptr->filter_type); - - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - info_ptr->channels = 1; - - else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) - info_ptr->channels = 3; - - else - info_ptr->channels = 1; - - if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) - info_ptr->channels++; - - info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth); - - info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width); -} - -#ifdef PNG_oFFs_SUPPORTED -void PNGAPI -png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr, - png_int_32 offset_x, png_int_32 offset_y, int unit_type) -{ - png_debug1(1, "in %s storage function", "oFFs"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - info_ptr->x_offset = offset_x; - info_ptr->y_offset = offset_y; - info_ptr->offset_unit_type = (png_byte)unit_type; - info_ptr->valid |= PNG_INFO_oFFs; -} -#endif - -#ifdef PNG_pCAL_SUPPORTED -void PNGAPI -png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr, - png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, - int nparams, png_const_charp units, png_charpp params) -{ - png_size_t length; - int i; - - png_debug1(1, "in %s storage function", "pCAL"); - - if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL - || (nparams > 0 && params == NULL)) - return; - - length = strlen(purpose) + 1; - png_debug1(3, "allocating purpose for info (%lu bytes)", - (unsigned long)length); - - /* TODO: validate format of calibration name and unit name */ - - /* Check that the type matches the specification. */ - if (type < 0 || type > 3) - png_error(png_ptr, "Invalid pCAL equation type"); - - if (nparams < 0 || nparams > 255) - png_error(png_ptr, "Invalid pCAL parameter count"); - - /* Validate params[nparams] */ - for (i=0; i<nparams; ++i) - { - if (params[i] == NULL || - !png_check_fp_string(params[i], strlen(params[i]))) - png_error(png_ptr, "Invalid format for pCAL parameter"); - } - - info_ptr->pcal_purpose = png_voidcast(png_charp, - png_malloc_warn(png_ptr, length)); - - if (info_ptr->pcal_purpose == NULL) - { - png_warning(png_ptr, "Insufficient memory for pCAL purpose"); - - return; - } - - memcpy(info_ptr->pcal_purpose, purpose, length); - - png_debug(3, "storing X0, X1, type, and nparams in info"); - info_ptr->pcal_X0 = X0; - info_ptr->pcal_X1 = X1; - info_ptr->pcal_type = (png_byte)type; - info_ptr->pcal_nparams = (png_byte)nparams; - - length = strlen(units) + 1; - png_debug1(3, "allocating units for info (%lu bytes)", - (unsigned long)length); - - info_ptr->pcal_units = png_voidcast(png_charp, - png_malloc_warn(png_ptr, length)); - - if (info_ptr->pcal_units == NULL) - { - png_warning(png_ptr, "Insufficient memory for pCAL units"); - - return; - } - - memcpy(info_ptr->pcal_units, units, length); - - info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr, - (png_size_t)((nparams + 1) * (sizeof (png_charp))))); - - if (info_ptr->pcal_params == NULL) - { - png_warning(png_ptr, "Insufficient memory for pCAL params"); - - return; - } - - memset(info_ptr->pcal_params, 0, (nparams + 1) * (sizeof (png_charp))); - - for (i = 0; i < nparams; i++) - { - length = strlen(params[i]) + 1; - png_debug2(3, "allocating parameter %d for info (%lu bytes)", i, - (unsigned long)length); - - info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length); - - if (info_ptr->pcal_params[i] == NULL) - { - png_warning(png_ptr, "Insufficient memory for pCAL parameter"); - - return; - } - - memcpy(info_ptr->pcal_params[i], params[i], length); - } - - info_ptr->valid |= PNG_INFO_pCAL; - info_ptr->free_me |= PNG_FREE_PCAL; -} -#endif - -#ifdef PNG_sCAL_SUPPORTED -void PNGAPI -png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr, - int unit, png_const_charp swidth, png_const_charp sheight) -{ - png_size_t lengthw = 0, lengthh = 0; - - png_debug1(1, "in %s storage function", "sCAL"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - /* Double check the unit (should never get here with an invalid - * unit unless this is an API call.) - */ - if (unit != 1 && unit != 2) - png_error(png_ptr, "Invalid sCAL unit"); - - if (swidth == NULL || (lengthw = strlen(swidth)) == 0 || - swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw)) - png_error(png_ptr, "Invalid sCAL width"); - - if (sheight == NULL || (lengthh = strlen(sheight)) == 0 || - sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh)) - png_error(png_ptr, "Invalid sCAL height"); - - info_ptr->scal_unit = (png_byte)unit; - - ++lengthw; - - png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw); - - info_ptr->scal_s_width = png_voidcast(png_charp, - png_malloc_warn(png_ptr, lengthw)); - - if (info_ptr->scal_s_width == NULL) - { - png_warning(png_ptr, "Memory allocation failed while processing sCAL"); - - return; - } - - memcpy(info_ptr->scal_s_width, swidth, lengthw); - - ++lengthh; - - png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh); - - info_ptr->scal_s_height = png_voidcast(png_charp, - png_malloc_warn(png_ptr, lengthh)); - - if (info_ptr->scal_s_height == NULL) - { - png_free (png_ptr, info_ptr->scal_s_width); - info_ptr->scal_s_width = NULL; - - png_warning(png_ptr, "Memory allocation failed while processing sCAL"); - - return; - } - - memcpy(info_ptr->scal_s_height, sheight, lengthh); - - info_ptr->valid |= PNG_INFO_sCAL; - info_ptr->free_me |= PNG_FREE_SCAL; -} - -# ifdef PNG_FLOATING_POINT_SUPPORTED -void PNGAPI -png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit, - double width, double height) -{ - png_debug1(1, "in %s storage function", "sCAL"); - - /* Check the arguments. */ - if (width <= 0) - png_warning(png_ptr, "Invalid sCAL width ignored"); - - else if (height <= 0) - png_warning(png_ptr, "Invalid sCAL height ignored"); - - else - { - /* Convert 'width' and 'height' to ASCII. */ - char swidth[PNG_sCAL_MAX_DIGITS+1]; - char sheight[PNG_sCAL_MAX_DIGITS+1]; - - png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width, - PNG_sCAL_PRECISION); - png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height, - PNG_sCAL_PRECISION); - - png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight); - } -} -# endif - -# ifdef PNG_FIXED_POINT_SUPPORTED -void PNGAPI -png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit, - png_fixed_point width, png_fixed_point height) -{ - png_debug1(1, "in %s storage function", "sCAL"); - - /* Check the arguments. */ - if (width <= 0) - png_warning(png_ptr, "Invalid sCAL width ignored"); - - else if (height <= 0) - png_warning(png_ptr, "Invalid sCAL height ignored"); - - else - { - /* Convert 'width' and 'height' to ASCII. */ - char swidth[PNG_sCAL_MAX_DIGITS+1]; - char sheight[PNG_sCAL_MAX_DIGITS+1]; - - png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width); - png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height); - - png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight); - } -} -# endif -#endif - -#ifdef PNG_pHYs_SUPPORTED -void PNGAPI -png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr, - png_uint_32 res_x, png_uint_32 res_y, int unit_type) -{ - png_debug1(1, "in %s storage function", "pHYs"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - info_ptr->x_pixels_per_unit = res_x; - info_ptr->y_pixels_per_unit = res_y; - info_ptr->phys_unit_type = (png_byte)unit_type; - info_ptr->valid |= PNG_INFO_pHYs; -} -#endif - -void PNGAPI -png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr, - png_const_colorp palette, int num_palette) -{ - - png_uint_32 max_palette_length; - - png_debug1(1, "in %s storage function", "PLTE"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ? - (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH; - - if (num_palette < 0 || num_palette > (int) max_palette_length) - { - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - png_error(png_ptr, "Invalid palette length"); - - else - { - png_warning(png_ptr, "Invalid palette length"); - - return; - } - } - - if ((num_palette > 0 && palette == NULL) || - (num_palette == 0 -# ifdef PNG_MNG_FEATURES_SUPPORTED - && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 -# endif - )) - { - png_error(png_ptr, "Invalid palette"); - } - - /* It may not actually be necessary to set png_ptr->palette here; - * we do it for backward compatibility with the way the png_handle_tRNS - * function used to do the allocation. - * - * 1.6.0: the above statement appears to be incorrect; something has to set - * the palette inside png_struct on read. - */ - png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0); - - /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead - * of num_palette entries, in case of an invalid PNG file or incorrect - * call to png_set_PLTE() with too-large sample values. - */ - png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr, - PNG_MAX_PALETTE_LENGTH * (sizeof (png_color)))); - - if (num_palette > 0) - memcpy(png_ptr->palette, palette, num_palette * (sizeof (png_color))); - info_ptr->palette = png_ptr->palette; - info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette; - - info_ptr->free_me |= PNG_FREE_PLTE; - - info_ptr->valid |= PNG_INFO_PLTE; -} - -#ifdef PNG_sBIT_SUPPORTED -void PNGAPI -png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr, - png_const_color_8p sig_bit) -{ - png_debug1(1, "in %s storage function", "sBIT"); - - if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL) - return; - - info_ptr->sig_bit = *sig_bit; - info_ptr->valid |= PNG_INFO_sBIT; -} -#endif - -#ifdef PNG_sRGB_SUPPORTED -void PNGAPI -png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent) -{ - png_debug1(1, "in %s storage function", "sRGB"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent); - png_colorspace_sync_info(png_ptr, info_ptr); -} - -void PNGAPI -png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr, - int srgb_intent) -{ - png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, - srgb_intent) != 0) - { - /* This causes the gAMA and cHRM to be written too */ - info_ptr->colorspace.flags |= - PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM; - } - - png_colorspace_sync_info(png_ptr, info_ptr); -} -#endif /* sRGB */ - - -#ifdef PNG_iCCP_SUPPORTED -void PNGAPI -png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, - png_const_charp name, int compression_type, - png_const_bytep profile, png_uint_32 proflen) -{ - png_charp new_iccp_name; - png_bytep new_iccp_profile; - png_size_t length; - - png_debug1(1, "in %s storage function", "iCCP"); - - if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL) - return; - - if (compression_type != PNG_COMPRESSION_TYPE_BASE) - png_app_error(png_ptr, "Invalid iCCP compression method"); - - /* Set the colorspace first because this validates the profile; do not - * override previously set app cHRM or gAMA here (because likely as not the - * application knows better than libpng what the correct values are.) Pass - * the info_ptr color_type field to png_colorspace_set_ICC because in the - * write case it has not yet been stored in png_ptr. - */ - { - int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name, - proflen, profile, info_ptr->color_type); - - png_colorspace_sync_info(png_ptr, info_ptr); - - /* Don't do any of the copying if the profile was bad, or inconsistent. */ - if (result == 0) - return; - - /* But do write the gAMA and cHRM chunks from the profile. */ - info_ptr->colorspace.flags |= - PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM; - } - - length = strlen(name)+1; - new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length)); - - if (new_iccp_name == NULL) - { - png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk"); - - return; - } - - memcpy(new_iccp_name, name, length); - new_iccp_profile = png_voidcast(png_bytep, - png_malloc_warn(png_ptr, proflen)); - - if (new_iccp_profile == NULL) - { - png_free(png_ptr, new_iccp_name); - png_benign_error(png_ptr, - "Insufficient memory to process iCCP profile"); - - return; - } - - memcpy(new_iccp_profile, profile, proflen); - - png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0); - - info_ptr->iccp_proflen = proflen; - info_ptr->iccp_name = new_iccp_name; - info_ptr->iccp_profile = new_iccp_profile; - info_ptr->free_me |= PNG_FREE_ICCP; - info_ptr->valid |= PNG_INFO_iCCP; -} -#endif - -#ifdef PNG_TEXT_SUPPORTED -void PNGAPI -png_set_text(png_const_structrp png_ptr, png_inforp info_ptr, - png_const_textp text_ptr, int num_text) -{ - int ret; - ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text); - - if (ret != 0) - png_error(png_ptr, "Insufficient memory to store text"); -} - -int /* PRIVATE */ -png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr, - png_const_textp text_ptr, int num_text) -{ - int i; - - png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11U : - (unsigned long)png_ptr->chunk_name); - - if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL) - return(0); - - /* Make sure we have enough space in the "text" array in info_struct - * to hold all of the incoming text_ptr objects. This compare can't overflow - * because max_text >= num_text (anyway, subtract of two positive integers - * can't overflow in any case.) - */ - if (num_text > info_ptr->max_text - info_ptr->num_text) - { - int old_num_text = info_ptr->num_text; - int max_text; - png_textp new_text = NULL; - - /* Calculate an appropriate max_text, checking for overflow. */ - max_text = old_num_text; - if (num_text <= INT_MAX - max_text) - { - max_text += num_text; - - /* Round up to a multiple of 8 */ - if (max_text < INT_MAX-8) - max_text = (max_text + 8) & ~0x7; - - else - max_text = INT_MAX; - - /* Now allocate a new array and copy the old members in; this does all - * the overflow checks. - */ - new_text = png_voidcast(png_textp,png_realloc_array(png_ptr, - info_ptr->text, old_num_text, max_text-old_num_text, - sizeof *new_text)); - } - - if (new_text == NULL) - { - png_chunk_report(png_ptr, "too many text chunks", - PNG_CHUNK_WRITE_ERROR); - - return 1; - } - - png_free(png_ptr, info_ptr->text); - - info_ptr->text = new_text; - info_ptr->free_me |= PNG_FREE_TEXT; - info_ptr->max_text = max_text; - /* num_text is adjusted below as the entries are copied in */ - - png_debug1(3, "allocated %d entries for info_ptr->text", max_text); - } - - for (i = 0; i < num_text; i++) - { - size_t text_length, key_len; - size_t lang_len, lang_key_len; - png_textp textp = &(info_ptr->text[info_ptr->num_text]); - - if (text_ptr[i].key == NULL) - continue; - - if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE || - text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST) - { - png_chunk_report(png_ptr, "text compression mode is out of range", - PNG_CHUNK_WRITE_ERROR); - continue; - } - - key_len = strlen(text_ptr[i].key); - - if (text_ptr[i].compression <= 0) - { - lang_len = 0; - lang_key_len = 0; - } - - else -# ifdef PNG_iTXt_SUPPORTED - { - /* Set iTXt data */ - - if (text_ptr[i].lang != NULL) - lang_len = strlen(text_ptr[i].lang); - - else - lang_len = 0; - - if (text_ptr[i].lang_key != NULL) - lang_key_len = strlen(text_ptr[i].lang_key); - - else - lang_key_len = 0; - } -# else /* iTXt */ - { - png_chunk_report(png_ptr, "iTXt chunk not supported", - PNG_CHUNK_WRITE_ERROR); - continue; - } -# endif - - if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0') - { - text_length = 0; -# ifdef PNG_iTXt_SUPPORTED - if (text_ptr[i].compression > 0) - textp->compression = PNG_ITXT_COMPRESSION_NONE; - - else -# endif - textp->compression = PNG_TEXT_COMPRESSION_NONE; - } - - else - { - text_length = strlen(text_ptr[i].text); - textp->compression = text_ptr[i].compression; - } - - textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr, - key_len + text_length + lang_len + lang_key_len + 4)); - - if (textp->key == NULL) - { - png_chunk_report(png_ptr, "text chunk: out of memory", - PNG_CHUNK_WRITE_ERROR); - - return 1; - } - - png_debug2(2, "Allocated %lu bytes at %p in png_set_text", - (unsigned long)(png_uint_32) - (key_len + lang_len + lang_key_len + text_length + 4), - textp->key); - - memcpy(textp->key, text_ptr[i].key, key_len); - *(textp->key + key_len) = '\0'; - - if (text_ptr[i].compression > 0) - { - textp->lang = textp->key + key_len + 1; - memcpy(textp->lang, text_ptr[i].lang, lang_len); - *(textp->lang + lang_len) = '\0'; - textp->lang_key = textp->lang + lang_len + 1; - memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len); - *(textp->lang_key + lang_key_len) = '\0'; - textp->text = textp->lang_key + lang_key_len + 1; - } - - else - { - textp->lang=NULL; - textp->lang_key=NULL; - textp->text = textp->key + key_len + 1; - } - - if (text_length != 0) - memcpy(textp->text, text_ptr[i].text, text_length); - - *(textp->text + text_length) = '\0'; - -# ifdef PNG_iTXt_SUPPORTED - if (textp->compression > 0) - { - textp->text_length = 0; - textp->itxt_length = text_length; - } - - else -# endif - { - textp->text_length = text_length; - textp->itxt_length = 0; - } - - info_ptr->num_text++; - png_debug1(3, "transferred text chunk %d", info_ptr->num_text); - } - - return(0); -} -#endif - -#ifdef PNG_tIME_SUPPORTED -void PNGAPI -png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr, - png_const_timep mod_time) -{ - png_debug1(1, "in %s storage function", "tIME"); - - if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL || - (png_ptr->mode & PNG_WROTE_tIME) != 0) - return; - - if (mod_time->month == 0 || mod_time->month > 12 || - mod_time->day == 0 || mod_time->day > 31 || - mod_time->hour > 23 || mod_time->minute > 59 || - mod_time->second > 60) - { - png_warning(png_ptr, "Ignoring invalid time value"); - - return; - } - - info_ptr->mod_time = *mod_time; - info_ptr->valid |= PNG_INFO_tIME; -} -#endif - -#ifdef PNG_tRNS_SUPPORTED -void PNGAPI -png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr, - png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color) -{ - png_debug1(1, "in %s storage function", "tRNS"); - - if (png_ptr == NULL || info_ptr == NULL) - - return; - - if (trans_alpha != NULL) - { - /* It may not actually be necessary to set png_ptr->trans_alpha here; - * we do it for backward compatibility with the way the png_handle_tRNS - * function used to do the allocation. - * - * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively - * relies on png_set_tRNS storing the information in png_struct - * (otherwise it won't be there for the code in pngrtran.c). - */ - - png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0); - - /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */ - png_ptr->trans_alpha = info_ptr->trans_alpha = png_voidcast(png_bytep, - png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH)); - - if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH) - memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans); - } - - if (trans_color != NULL) - { -#ifdef PNG_WARNINGS_SUPPORTED - if (info_ptr->bit_depth < 16) - { - int sample_max = (1 << info_ptr->bit_depth) - 1; - - if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY && - trans_color->gray > sample_max) || - (info_ptr->color_type == PNG_COLOR_TYPE_RGB && - (trans_color->red > sample_max || - trans_color->green > sample_max || - trans_color->blue > sample_max))) - png_warning(png_ptr, - "tRNS chunk has out-of-range samples for bit_depth"); - } -#endif - - info_ptr->trans_color = *trans_color; - - if (num_trans == 0) - num_trans = 1; - } - - info_ptr->num_trans = (png_uint_16)num_trans; - - if (num_trans != 0) - { - info_ptr->valid |= PNG_INFO_tRNS; - info_ptr->free_me |= PNG_FREE_TRNS; - } -} -#endif - -#ifdef PNG_sPLT_SUPPORTED -void PNGAPI -png_set_sPLT(png_const_structrp png_ptr, - png_inforp info_ptr, png_const_sPLT_tp entries, int nentries) -/* - * entries - array of png_sPLT_t structures - * to be added to the list of palettes - * in the info structure. - * - * nentries - number of palette structures to be - * added. - */ -{ - png_sPLT_tp np; - - if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL) - return; - - /* Use the internal realloc function, which checks for all the possible - * overflows. Notice that the parameters are (int) and (size_t) - */ - np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr, - info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries, - sizeof *np)); - - if (np == NULL) - { - /* Out of memory or too many chunks */ - png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR); - - return; - } - - png_free(png_ptr, info_ptr->splt_palettes); - info_ptr->splt_palettes = np; - info_ptr->free_me |= PNG_FREE_SPLT; - - np += info_ptr->splt_palettes_num; - - do - { - png_size_t length; - - /* Skip invalid input entries */ - if (entries->name == NULL || entries->entries == NULL) - { - /* png_handle_sPLT doesn't do this, so this is an app error */ - png_app_error(png_ptr, "png_set_sPLT: invalid sPLT"); - /* Just skip the invalid entry */ - continue; - } - - np->depth = entries->depth; - - /* In the event of out-of-memory just return - there's no point keeping - * on trying to add sPLT chunks. - */ - length = strlen(entries->name) + 1; - np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length)); - - if (np->name == NULL) - break; - - memcpy(np->name, entries->name, length); - - /* IMPORTANT: we have memory now that won't get freed if something else - * goes wrong; this code must free it. png_malloc_array produces no - * warnings; use a png_chunk_report (below) if there is an error. - */ - np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr, - entries->nentries, sizeof (png_sPLT_entry))); - - if (np->entries == NULL) - { - png_free(png_ptr, np->name); - np->name = NULL; - break; - } - - np->nentries = entries->nentries; - /* This multiply can't overflow because png_malloc_array has already - * checked it when doing the allocation. - */ - memcpy(np->entries, entries->entries, - entries->nentries * sizeof (png_sPLT_entry)); - - /* Note that 'continue' skips the advance of the out pointer and out - * count, so an invalid entry is not added. - */ - info_ptr->valid |= PNG_INFO_sPLT; - ++(info_ptr->splt_palettes_num); - ++np; - } - while (++entries, --nentries); - - if (nentries > 0) - png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR); -} -#endif /* sPLT */ - -#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED -static png_byte -check_location(png_const_structrp png_ptr, int location) -{ - location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT); - - /* New in 1.6.0; copy the location and check it. This is an API - * change; previously the app had to use the - * png_set_unknown_chunk_location API below for each chunk. - */ - if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0) - { - /* Write struct, so unknown chunks come from the app */ - png_app_warning(png_ptr, - "png_set_unknown_chunks now expects a valid location"); - /* Use the old behavior */ - location = (png_byte)(png_ptr->mode & - (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)); - } - - /* This need not be an internal error - if the app calls - * png_set_unknown_chunks on a read pointer it must get the location right. - */ - if (location == 0) - png_error(png_ptr, "invalid location in png_set_unknown_chunks"); - - /* Now reduce the location to the top-most set bit by removing each least - * significant bit in turn. - */ - while (location != (location & -location)) - location &= ~(location & -location); - - /* The cast is safe because 'location' is a bit mask and only the low four - * bits are significant. - */ - return (png_byte)location; -} - -void PNGAPI -png_set_unknown_chunks(png_const_structrp png_ptr, - png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns) -{ - png_unknown_chunkp np; - - if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 || - unknowns == NULL) - return; - - /* Check for the failure cases where support has been disabled at compile - * time. This code is hardly ever compiled - it's here because - * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this - * code) but may be meaningless if the read or write handling of unknown - * chunks is not compiled in. - */ -# if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \ - defined(PNG_READ_SUPPORTED) - if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) - { - png_app_error(png_ptr, "no unknown chunk support on read"); - - return; - } -# endif -# if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \ - defined(PNG_WRITE_SUPPORTED) - if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) - { - png_app_error(png_ptr, "no unknown chunk support on write"); - - return; - } -# endif - - /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that - * unknown critical chunks could be lost with just a warning resulting in - * undefined behavior. Now png_chunk_report is used to provide behavior - * appropriate to read or write. - */ - np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr, - info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns, - sizeof *np)); - - if (np == NULL) - { - png_chunk_report(png_ptr, "too many unknown chunks", - PNG_CHUNK_WRITE_ERROR); - - return; - } - - png_free(png_ptr, info_ptr->unknown_chunks); - info_ptr->unknown_chunks = np; /* safe because it is initialized */ - info_ptr->free_me |= PNG_FREE_UNKN; - - np += info_ptr->unknown_chunks_num; - - /* Increment unknown_chunks_num each time round the loop to protect the - * just-allocated chunk data. - */ - for (; num_unknowns > 0; --num_unknowns, ++unknowns) - { - memcpy(np->name, unknowns->name, (sizeof np->name)); - np->name[(sizeof np->name)-1] = '\0'; - np->location = check_location(png_ptr, unknowns->location); - - if (unknowns->size == 0) - { - np->data = NULL; - np->size = 0; - } - - else - { - np->data = png_voidcast(png_bytep, - png_malloc_base(png_ptr, unknowns->size)); - - if (np->data == NULL) - { - png_chunk_report(png_ptr, "unknown chunk: out of memory", - PNG_CHUNK_WRITE_ERROR); - /* But just skip storing the unknown chunk */ - continue; - } - - memcpy(np->data, unknowns->data, unknowns->size); - np->size = unknowns->size; - } - - /* These increments are skipped on out-of-memory for the data - the - * unknown chunk entry gets overwritten if the png_chunk_report returns. - * This is correct in the read case (the chunk is just dropped.) - */ - ++np; - ++(info_ptr->unknown_chunks_num); - } -} - -void PNGAPI -png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr, - int chunk, int location) -{ - /* This API is pretty pointless in 1.6.0 because the location can be set - * before the call to png_set_unknown_chunks. - * - * TODO: add a png_app_warning in 1.7 - */ - if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 && - chunk < info_ptr->unknown_chunks_num) - { - if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0) - { - png_app_error(png_ptr, "invalid unknown chunk location"); - /* Fake out the pre 1.6.0 behavior: */ - if ((location & PNG_HAVE_IDAT) != 0) /* undocumented! */ - location = PNG_AFTER_IDAT; - - else - location = PNG_HAVE_IHDR; /* also undocumented */ - } - - info_ptr->unknown_chunks[chunk].location = - check_location(png_ptr, location); - } -} -#endif /* STORE_UNKNOWN_CHUNKS */ - -#ifdef PNG_MNG_FEATURES_SUPPORTED -png_uint_32 PNGAPI -png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features) -{ - png_debug(1, "in png_permit_mng_features"); - - if (png_ptr == NULL) - return 0; - - png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES; - - return png_ptr->mng_features_permitted; -} -#endif - -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED -static unsigned int -add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep) -{ - unsigned int i; - - /* Utility function: update the 'keep' state of a chunk if it is already in - * the list, otherwise add it to the list. - */ - for (i=0; i<count; ++i, list += 5) - { - if (memcmp(list, add, 4) == 0) - { - list[4] = (png_byte)keep; - - return count; - } - } - - if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT) - { - ++count; - memcpy(list, add, 4); - list[4] = (png_byte)keep; - } - - return count; -} - -void PNGAPI -png_set_keep_unknown_chunks(png_structrp png_ptr, int keep, - png_const_bytep chunk_list, int num_chunks_in) -{ - png_bytep new_list; - unsigned int num_chunks, old_num_chunks; - - if (png_ptr == NULL) - return; - - if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST) - { - png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep"); - - return; - } - - if (num_chunks_in <= 0) - { - png_ptr->unknown_default = keep; - - /* '0' means just set the flags, so stop here */ - if (num_chunks_in == 0) - return; - } - - if (num_chunks_in < 0) - { - /* Ignore all unknown chunks and all chunks recognized by - * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND - */ - static PNG_CONST png_byte chunks_to_ignore[] = { - 98, 75, 71, 68, '\0', /* bKGD */ - 99, 72, 82, 77, '\0', /* cHRM */ - 103, 65, 77, 65, '\0', /* gAMA */ - 104, 73, 83, 84, '\0', /* hIST */ - 105, 67, 67, 80, '\0', /* iCCP */ - 105, 84, 88, 116, '\0', /* iTXt */ - 111, 70, 70, 115, '\0', /* oFFs */ - 112, 67, 65, 76, '\0', /* pCAL */ - 112, 72, 89, 115, '\0', /* pHYs */ - 115, 66, 73, 84, '\0', /* sBIT */ - 115, 67, 65, 76, '\0', /* sCAL */ - 115, 80, 76, 84, '\0', /* sPLT */ - 115, 84, 69, 82, '\0', /* sTER */ - 115, 82, 71, 66, '\0', /* sRGB */ - 116, 69, 88, 116, '\0', /* tEXt */ - 116, 73, 77, 69, '\0', /* tIME */ - 122, 84, 88, 116, '\0' /* zTXt */ - }; - - chunk_list = chunks_to_ignore; - num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U; - } - - else /* num_chunks_in > 0 */ - { - if (chunk_list == NULL) - { - /* Prior to 1.6.0 this was silently ignored, now it is an app_error - * which can be switched off. - */ - png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list"); - - return; - } - - num_chunks = num_chunks_in; - } - - old_num_chunks = png_ptr->num_chunk_list; - if (png_ptr->chunk_list == NULL) - old_num_chunks = 0; - - /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow. - */ - if (num_chunks + old_num_chunks > UINT_MAX/5) - { - png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks"); - - return; - } - - /* If these chunks are being reset to the default then no more memory is - * required because add_one_chunk above doesn't extend the list if the 'keep' - * parameter is the default. - */ - if (keep != 0) - { - new_list = png_voidcast(png_bytep, png_malloc(png_ptr, - 5 * (num_chunks + old_num_chunks))); - - if (old_num_chunks > 0) - memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks); - } - - else if (old_num_chunks > 0) - new_list = png_ptr->chunk_list; - - else - new_list = NULL; - - /* Add the new chunks together with each one's handling code. If the chunk - * already exists the code is updated, otherwise the chunk is added to the - * end. (In libpng 1.6.0 order no longer matters because this code enforces - * the earlier convention that the last setting is the one that is used.) - */ - if (new_list != NULL) - { - png_const_bytep inlist; - png_bytep outlist; - unsigned int i; - - for (i=0; i<num_chunks; ++i) - { - old_num_chunks = add_one_chunk(new_list, old_num_chunks, - chunk_list+5*i, keep); - } - - /* Now remove any spurious 'default' entries. */ - num_chunks = 0; - for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5) - { - if (inlist[4]) - { - if (outlist != inlist) - memcpy(outlist, inlist, 5); - outlist += 5; - ++num_chunks; - } - } - - /* This means the application has removed all the specialized handling. */ - if (num_chunks == 0) - { - if (png_ptr->chunk_list != new_list) - png_free(png_ptr, new_list); - - new_list = NULL; - } - } - - else - num_chunks = 0; - - png_ptr->num_chunk_list = num_chunks; - - if (png_ptr->chunk_list != new_list) - { - if (png_ptr->chunk_list != NULL) - png_free(png_ptr, png_ptr->chunk_list); - - png_ptr->chunk_list = new_list; - } -} -#endif - -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED -void PNGAPI -png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr, - png_user_chunk_ptr read_user_chunk_fn) -{ - png_debug(1, "in png_set_read_user_chunk_fn"); - - if (png_ptr == NULL) - return; - - png_ptr->read_user_chunk_fn = read_user_chunk_fn; - png_ptr->user_chunk_ptr = user_chunk_ptr; -} -#endif - -#ifdef PNG_INFO_IMAGE_SUPPORTED -void PNGAPI -png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr, - png_bytepp row_pointers) -{ - png_debug1(1, "in %s storage function", "rows"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - if (info_ptr->row_pointers != NULL && - (info_ptr->row_pointers != row_pointers)) - png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); - - info_ptr->row_pointers = row_pointers; - - if (row_pointers != NULL) - info_ptr->valid |= PNG_INFO_IDAT; -} -#endif - -void PNGAPI -png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size) -{ - if (png_ptr == NULL) - return; - - if (size == 0 || size > PNG_UINT_31_MAX) - png_error(png_ptr, "invalid compression buffer size"); - -# ifdef PNG_SEQUENTIAL_READ_SUPPORTED - if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) - { - png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */ - return; - } -# endif - -# ifdef PNG_WRITE_SUPPORTED - if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) - { - if (png_ptr->zowner != 0) - { - png_warning(png_ptr, - "Compression buffer size cannot be changed because it is in use"); - - return; - } - -#ifndef __COVERITY__ - /* Some compilers complain that this is always false. However, it - * can be true when integer overflow happens. - */ - if (size > ZLIB_IO_MAX) - { - png_warning(png_ptr, - "Compression buffer size limited to system maximum"); - size = ZLIB_IO_MAX; /* must fit */ - } -#endif - - if (size < 6) - { - /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH - * if this is permitted. - */ - png_warning(png_ptr, - "Compression buffer size cannot be reduced below 6"); - - return; - } - - if (png_ptr->zbuffer_size != size) - { - png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); - png_ptr->zbuffer_size = (uInt)size; - } - } -# endif -} - -void PNGAPI -png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask) -{ - if (png_ptr != NULL && info_ptr != NULL) - info_ptr->valid &= ~mask; -} - - -#ifdef PNG_SET_USER_LIMITS_SUPPORTED -/* This function was added to libpng 1.2.6 */ -void PNGAPI -png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max, - png_uint_32 user_height_max) -{ - /* Images with dimensions larger than these limits will be - * rejected by png_set_IHDR(). To accept any PNG datastream - * regardless of dimensions, set both limits to 0x7fffffff. - */ - if (png_ptr == NULL) - return; - - png_ptr->user_width_max = user_width_max; - png_ptr->user_height_max = user_height_max; -} - -/* This function was added to libpng 1.4.0 */ -void PNGAPI -png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max) -{ - if (png_ptr != NULL) - png_ptr->user_chunk_cache_max = user_chunk_cache_max; -} - -/* This function was added to libpng 1.4.1 */ -void PNGAPI -png_set_chunk_malloc_max (png_structrp png_ptr, - png_alloc_size_t user_chunk_malloc_max) -{ - if (png_ptr != NULL) - png_ptr->user_chunk_malloc_max = user_chunk_malloc_max; -} -#endif /* ?SET_USER_LIMITS */ - - -#ifdef PNG_BENIGN_ERRORS_SUPPORTED -void PNGAPI -png_set_benign_errors(png_structrp png_ptr, int allowed) -{ - png_debug(1, "in png_set_benign_errors"); - - /* If allowed is 1, png_benign_error() is treated as a warning. - * - * If allowed is 0, png_benign_error() is treated as an error (which - * is the default behavior if png_set_benign_errors() is not called). - */ - - if (allowed != 0) - png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN | - PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN; - - else - png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN | - PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN); -} -#endif /* BENIGN_ERRORS */ - -#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED - /* Whether to report invalid palette index; added at libng-1.5.10. - * It is possible for an indexed (color-type==3) PNG file to contain - * pixels with invalid (out-of-range) indexes if the PLTE chunk has - * fewer entries than the image's bit-depth would allow. We recover - * from this gracefully by filling any incomplete palette with zeros - * (opaque black). By default, when this occurs libpng will issue - * a benign error. This API can be used to override that behavior. - */ -void PNGAPI -png_set_check_for_invalid_index(png_structrp png_ptr, int allowed) -{ - png_debug(1, "in png_set_check_for_invalid_index"); - - if (allowed > 0) - png_ptr->num_palette_max = 0; - - else - png_ptr->num_palette_max = -1; -} -#endif - -#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) || \ - defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) -/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, - * and if invalid, correct the keyword rather than discarding the entire - * chunk. The PNG 1.0 specification requires keywords 1-79 characters in - * length, forbids leading or trailing whitespace, multiple internal spaces, - * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. - * - * The 'new_key' buffer must be 80 characters in size (for the keyword plus a - * trailing '\0'). If this routine returns 0 then there was no keyword, or a - * valid one could not be generated, and the caller must png_error. - */ -png_uint_32 /* PRIVATE */ -png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key) -{ - png_const_charp orig_key = key; - png_uint_32 key_len = 0; - int bad_character = 0; - int space = 1; - - png_debug(1, "in png_check_keyword"); - - if (key == NULL) - { - *new_key = 0; - return 0; - } - - while (*key && key_len < 79) - { - png_byte ch = (png_byte)*key++; - - if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/)) - *new_key++ = ch, ++key_len, space = 0; - - else if (space == 0) - { - /* A space or an invalid character when one wasn't seen immediately - * before; output just a space. - */ - *new_key++ = 32, ++key_len, space = 1; - - /* If the character was not a space then it is invalid. */ - if (ch != 32) - bad_character = ch; - } - - else if (bad_character == 0) - bad_character = ch; /* just skip it, record the first error */ - } - - if (key_len > 0 && space != 0) /* trailing space */ - { - --key_len, --new_key; - if (bad_character == 0) - bad_character = 32; - } - - /* Terminate the keyword */ - *new_key = 0; - - if (key_len == 0) - return 0; - -#ifdef PNG_WARNINGS_SUPPORTED - /* Try to only output one warning per keyword: */ - if (*key != 0) /* keyword too long */ - png_warning(png_ptr, "keyword truncated"); - - else if (bad_character != 0) - { - PNG_WARNING_PARAMETERS(p) - - png_warning_parameter(p, 1, orig_key); - png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character); - - png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'"); - } -#endif /* WARNINGS */ - - return key_len; -} -#endif /* TEXT || pCAL || iCCP || sPLT */ -#endif /* READ || WRITE */ diff --git a/third_party/libpng/pngstruct.h b/third_party/libpng/pngstruct.h deleted file mode 100644 index c1f35edef5..0000000000 --- a/third_party/libpng/pngstruct.h +++ /dev/null @@ -1,483 +0,0 @@ - -/* pngstruct.h - header file for PNG reference library - * - * Last changed in libpng 1.6.18 [July 23, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -/* The structure that holds the information to read and write PNG files. - * The only people who need to care about what is inside of this are the - * people who will be modifying the library for their own special needs. - * It should NOT be accessed directly by an application. - */ - -#ifndef PNGSTRUCT_H -#define PNGSTRUCT_H -/* zlib.h defines the structure z_stream, an instance of which is included - * in this structure and is required for decompressing the LZ compressed - * data in PNG files. - */ -#ifndef ZLIB_CONST - /* We must ensure that zlib uses 'const' in declarations. */ -# define ZLIB_CONST -#endif -#include "zlib.h" -#ifdef const - /* zlib.h sometimes #defines const to nothing, undo this. */ -# undef const -#endif - -/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility - * with older builds. - */ -#if ZLIB_VERNUM < 0x1260 -# define PNGZ_MSG_CAST(s) png_constcast(char*,s) -# define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b) -#else -# define PNGZ_MSG_CAST(s) (s) -# define PNGZ_INPUT_CAST(b) (b) -#endif - -/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib - * can handle at once. This type need be no larger than 16 bits (so maximum of - * 65535), this define allows us to discover how big it is, but limited by the - * maximuum for png_size_t. The value can be overriden in a library build - * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably - * lower value (e.g. 255 works). A lower value may help memory usage (slightly) - * and may even improve performance on some systems (and degrade it on others.) - */ -#ifndef ZLIB_IO_MAX -# define ZLIB_IO_MAX ((uInt)-1) -#endif - -#ifdef PNG_WRITE_SUPPORTED -/* The type of a compression buffer list used by the write code. */ -typedef struct png_compression_buffer -{ - struct png_compression_buffer *next; - png_byte output[1]; /* actually zbuf_size */ -} png_compression_buffer, *png_compression_bufferp; - -#define PNG_COMPRESSION_BUFFER_SIZE(pp)\ - (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size) -#endif - -/* Colorspace support; structures used in png_struct, png_info and in internal - * functions to hold and communicate information about the color space. - * - * PNG_COLORSPACE_SUPPORTED is only required if the application will perform - * colorspace corrections, otherwise all the colorspace information can be - * skipped and the size of libpng can be reduced (significantly) by compiling - * out the colorspace support. - */ -#ifdef PNG_COLORSPACE_SUPPORTED -/* The chromaticities of the red, green and blue colorants and the chromaticity - * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)). - */ -typedef struct png_xy -{ - png_fixed_point redx, redy; - png_fixed_point greenx, greeny; - png_fixed_point bluex, bluey; - png_fixed_point whitex, whitey; -} png_xy; - -/* The same data as above but encoded as CIE XYZ values. When this data comes - * from chromaticities the sum of the Y values is assumed to be 1.0 - */ -typedef struct png_XYZ -{ - png_fixed_point red_X, red_Y, red_Z; - png_fixed_point green_X, green_Y, green_Z; - png_fixed_point blue_X, blue_Y, blue_Z; -} png_XYZ; -#endif /* COLORSPACE */ - -#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) -/* A colorspace is all the above plus, potentially, profile information; - * however at present libpng does not use the profile internally so it is only - * stored in the png_info struct (if iCCP is supported.) The rendering intent - * is retained here and is checked. - * - * The file gamma encoding information is also stored here and gamma correction - * is done by libpng, whereas color correction must currently be done by the - * application. - */ -typedef struct png_colorspace -{ -#ifdef PNG_GAMMA_SUPPORTED - png_fixed_point gamma; /* File gamma */ -#endif - -#ifdef PNG_COLORSPACE_SUPPORTED - png_xy end_points_xy; /* End points as chromaticities */ - png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */ - png_uint_16 rendering_intent; /* Rendering intent of a profile */ -#endif - - /* Flags are always defined to simplify the code. */ - png_uint_16 flags; /* As defined below */ -} png_colorspace, * PNG_RESTRICT png_colorspacerp; - -typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp; - -/* General flags for the 'flags' field */ -#define PNG_COLORSPACE_HAVE_GAMMA 0x0001 -#define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002 -#define PNG_COLORSPACE_HAVE_INTENT 0x0004 -#define PNG_COLORSPACE_FROM_gAMA 0x0008 -#define PNG_COLORSPACE_FROM_cHRM 0x0010 -#define PNG_COLORSPACE_FROM_sRGB 0x0020 -#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040 -#define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */ -#define PNG_COLORSPACE_INVALID 0x8000 -#define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags)) -#endif /* COLORSPACE || GAMMA */ - -struct png_struct_def -{ -#ifdef PNG_SETJMP_SUPPORTED - jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */ - png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ - jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */ - size_t jmp_buf_size; /* size of the above, if allocated */ -#endif - png_error_ptr error_fn; /* function for printing errors and aborting */ -#ifdef PNG_WARNINGS_SUPPORTED - png_error_ptr warning_fn; /* function for printing warnings */ -#endif - png_voidp error_ptr; /* user supplied struct for error functions */ - png_rw_ptr write_data_fn; /* function for writing output data */ - png_rw_ptr read_data_fn; /* function for reading input data */ - png_voidp io_ptr; /* ptr to application struct for I/O functions */ - -#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED - png_user_transform_ptr read_user_transform_fn; /* user read transform */ -#endif - -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED - png_user_transform_ptr write_user_transform_fn; /* user write transform */ -#endif - -/* These were added in libpng-1.0.2 */ -#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED -#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ - defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) - png_voidp user_transform_ptr; /* user supplied struct for user transform */ - png_byte user_transform_depth; /* bit depth of user transformed pixels */ - png_byte user_transform_channels; /* channels in user transformed pixels */ -#endif -#endif - - png_uint_32 mode; /* tells us where we are in the PNG file */ - png_uint_32 flags; /* flags indicating various things to libpng */ - png_uint_32 transformations; /* which transformations to perform */ - - png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */ - z_stream zstream; /* decompression structure */ - -#ifdef PNG_WRITE_SUPPORTED - png_compression_bufferp zbuffer_list; /* Created on demand during write */ - uInt zbuffer_size; /* size of the actual buffer */ - - int zlib_level; /* holds zlib compression level */ - int zlib_method; /* holds zlib compression method */ - int zlib_window_bits; /* holds zlib compression window bits */ - int zlib_mem_level; /* holds zlib compression memory level */ - int zlib_strategy; /* holds zlib compression strategy */ -#endif -/* Added at libpng 1.5.4 */ -#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED - int zlib_text_level; /* holds zlib compression level */ - int zlib_text_method; /* holds zlib compression method */ - int zlib_text_window_bits; /* holds zlib compression window bits */ - int zlib_text_mem_level; /* holds zlib compression memory level */ - int zlib_text_strategy; /* holds zlib compression strategy */ -#endif -/* End of material added at libpng 1.5.4 */ -/* Added at libpng 1.6.0 */ -#ifdef PNG_WRITE_SUPPORTED - int zlib_set_level; /* Actual values set into the zstream on write */ - int zlib_set_method; - int zlib_set_window_bits; - int zlib_set_mem_level; - int zlib_set_strategy; -#endif - - png_uint_32 width; /* width of image in pixels */ - png_uint_32 height; /* height of image in pixels */ - png_uint_32 num_rows; /* number of rows in current pass */ - png_uint_32 usr_width; /* width of row at start of write */ - png_size_t rowbytes; /* size of row in bytes */ - png_uint_32 iwidth; /* width of current interlaced row in pixels */ - png_uint_32 row_number; /* current row in interlace pass */ - png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ - png_bytep prev_row; /* buffer to save previous (unfiltered) row. - * While reading this is a pointer into - * big_prev_row; while writing it is separately - * allocated if needed. - */ - png_bytep row_buf; /* buffer to save current (unfiltered) row. - * While reading, this is a pointer into - * big_row_buf; while writing it is separately - * allocated. - */ -#ifdef PNG_WRITE_FILTER_SUPPORTED - png_bytep try_row; /* buffer to save trial row when filtering */ - png_bytep tst_row; /* buffer to save best trial row when filtering */ -#endif - png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ - - png_uint_32 idat_size; /* current IDAT size for read */ - png_uint_32 crc; /* current chunk CRC value */ - png_colorp palette; /* palette from the input file */ - png_uint_16 num_palette; /* number of color entries in palette */ - -/* Added at libpng-1.5.10 */ -#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED - int num_palette_max; /* maximum palette index found in IDAT */ -#endif - - png_uint_16 num_trans; /* number of transparency values */ - png_byte compression; /* file compression type (always 0) */ - png_byte filter; /* file filter type (always 0) */ - png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ - png_byte pass; /* current interlace pass (0 - 6) */ - png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */ - png_byte color_type; /* color type of file */ - png_byte bit_depth; /* bit depth of file */ - png_byte usr_bit_depth; /* bit depth of users row: write only */ - png_byte pixel_depth; /* number of bits per pixel */ - png_byte channels; /* number of channels in file */ -#ifdef PNG_WRITE_SUPPORTED - png_byte usr_channels; /* channels at start of write: write only */ -#endif - png_byte sig_bytes; /* magic bytes read/written from start of file */ - png_byte maximum_pixel_depth; - /* pixel depth used for the row buffers */ - png_byte transformed_pixel_depth; - /* pixel depth after read/write transforms */ -#if PNG_ZLIB_VERNUM >= 0x1240 - png_byte zstream_start; /* at start of an input zlib stream */ -#endif /* Zlib >= 1.2.4 */ -#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) - png_uint_16 filler; /* filler bytes for pixel expansion */ -#endif - -#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) - png_byte background_gamma_type; - png_fixed_point background_gamma; - png_color_16 background; /* background color in screen gamma space */ -#ifdef PNG_READ_GAMMA_SUPPORTED - png_color_16 background_1; /* background normalized to gamma 1.0 */ -#endif -#endif /* bKGD */ - -#ifdef PNG_WRITE_FLUSH_SUPPORTED - png_flush_ptr output_flush_fn; /* Function for flushing output */ - png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ - png_uint_32 flush_rows; /* number of rows written since last flush */ -#endif - -#ifdef PNG_READ_GAMMA_SUPPORTED - int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ - png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ - - png_bytep gamma_table; /* gamma table for 8-bit depth files */ - png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ -#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ - defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) - png_bytep gamma_from_1; /* converts from 1.0 to screen */ - png_bytep gamma_to_1; /* converts from file to 1.0 */ - png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ - png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ -#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ -#endif - -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) - png_color_8 sig_bit; /* significant bits in each available channel */ -#endif - -#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) - png_color_8 shift; /* shift for significant bit tranformation */ -#endif - -#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ - || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - png_bytep trans_alpha; /* alpha values for paletted files */ - png_color_16 trans_color; /* transparent color for non-paletted files */ -#endif - - png_read_status_ptr read_row_fn; /* called after each row is decoded */ - png_write_status_ptr write_row_fn; /* called after each row is encoded */ -#ifdef PNG_PROGRESSIVE_READ_SUPPORTED - png_progressive_info_ptr info_fn; /* called after header data fully read */ - png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ - png_progressive_end_ptr end_fn; /* called after image is complete */ - png_bytep save_buffer_ptr; /* current location in save_buffer */ - png_bytep save_buffer; /* buffer for previously read data */ - png_bytep current_buffer_ptr; /* current location in current_buffer */ - png_bytep current_buffer; /* buffer for recently used data */ - png_uint_32 push_length; /* size of current input chunk */ - png_uint_32 skip_length; /* bytes to skip in input data */ - png_size_t save_buffer_size; /* amount of data now in save_buffer */ - png_size_t save_buffer_max; /* total size of save_buffer */ - png_size_t buffer_size; /* total amount of available input data */ - png_size_t current_buffer_size; /* amount of data now in current_buffer */ - int process_mode; /* what push library is currently doing */ - int cur_palette; /* current push library palette index */ - -#endif /* PROGRESSIVE_READ */ - -#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) -/* For the Borland special 64K segment handler */ - png_bytepp offset_table_ptr; - png_bytep offset_table; - png_uint_16 offset_table_number; - png_uint_16 offset_table_count; - png_uint_16 offset_table_count_free; -#endif - -#ifdef PNG_READ_QUANTIZE_SUPPORTED - png_bytep palette_lookup; /* lookup table for quantizing */ - png_bytep quantize_index; /* index translation for palette files */ -#endif - -/* Options */ -#ifdef PNG_SET_OPTION_SUPPORTED - png_byte options; /* On/off state (up to 4 options) */ -#endif - -#if PNG_LIBPNG_VER < 10700 -/* To do: remove this from libpng-1.7 */ -#ifdef PNG_TIME_RFC1123_SUPPORTED - char time_buffer[29]; /* String to hold RFC 1123 time text */ -#endif -#endif - -/* New members added in libpng-1.0.6 */ - - png_uint_32 free_me; /* flags items libpng is responsible for freeing */ - -#ifdef PNG_USER_CHUNKS_SUPPORTED - png_voidp user_chunk_ptr; -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED - png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ -#endif -#endif - -#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED - int unknown_default; /* As PNG_HANDLE_* */ - unsigned int num_chunk_list; /* Number of entries in the list */ - png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name - * followed by a PNG_HANDLE_* byte */ -#endif - -/* New members added in libpng-1.0.3 */ -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED - png_byte rgb_to_gray_status; - /* Added in libpng 1.5.5 to record setting of coefficients: */ - png_byte rgb_to_gray_coefficients_set; - /* These were changed from png_byte in libpng-1.0.6 */ - png_uint_16 rgb_to_gray_red_coeff; - png_uint_16 rgb_to_gray_green_coeff; - /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ -#endif - -/* New member added in libpng-1.0.4 (renamed in 1.0.9) */ -#if defined(PNG_MNG_FEATURES_SUPPORTED) -/* Changed from png_byte to png_uint_32 at version 1.2.0 */ - png_uint_32 mng_features_permitted; -#endif - -/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ -#ifdef PNG_MNG_FEATURES_SUPPORTED - png_byte filter_type; -#endif - -/* New members added in libpng-1.2.0 */ - -/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ -#ifdef PNG_USER_MEM_SUPPORTED - png_voidp mem_ptr; /* user supplied struct for mem functions */ - png_malloc_ptr malloc_fn; /* function for allocating memory */ - png_free_ptr free_fn; /* function for freeing memory */ -#endif - -/* New member added in libpng-1.0.13 and 1.2.0 */ - png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ - -#ifdef PNG_READ_QUANTIZE_SUPPORTED -/* The following three members were added at version 1.0.14 and 1.2.4 */ - png_bytep quantize_sort; /* working sort array */ - png_bytep index_to_palette; /* where the original index currently is - in the palette */ - png_bytep palette_to_index; /* which original index points to this - palette color */ -#endif - -/* New members added in libpng-1.0.16 and 1.2.6 */ - png_byte compression_type; - -#ifdef PNG_USER_LIMITS_SUPPORTED - png_uint_32 user_width_max; - png_uint_32 user_height_max; - - /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown - * chunks that can be stored (0 means unlimited). - */ - png_uint_32 user_chunk_cache_max; - - /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk - * can occupy when decompressed. 0 means unlimited. - */ - png_alloc_size_t user_chunk_malloc_max; -#endif - -/* New member added in libpng-1.0.25 and 1.2.17 */ -#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - /* Temporary storage for unknown chunk that the library doesn't recognize, - * used while reading the chunk. - */ - png_unknown_chunk unknown_chunk; -#endif - -/* New member added in libpng-1.2.26 */ - png_size_t old_big_row_buf_size; - -#ifdef PNG_READ_SUPPORTED -/* New member added in libpng-1.2.30 */ - png_bytep read_buffer; /* buffer for reading chunk data */ - png_alloc_size_t read_buffer_size; /* current size of the buffer */ -#endif -#ifdef PNG_SEQUENTIAL_READ_SUPPORTED - uInt IDAT_read_size; /* limit on read buffer size for IDAT */ -#endif - -#ifdef PNG_IO_STATE_SUPPORTED -/* New member added in libpng-1.4.0 */ - png_uint_32 io_state; -#endif - -/* New member added in libpng-1.5.6 */ - png_bytep big_prev_row; - -/* New member added in libpng-1.5.7 */ - void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, - png_bytep row, png_const_bytep prev_row); - -#ifdef PNG_READ_SUPPORTED -#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) - png_colorspace colorspace; -#endif -#endif -}; -#endif /* PNGSTRUCT_H */ diff --git a/third_party/libpng/pngtest.c b/third_party/libpng/pngtest.c deleted file mode 100644 index 5d9f02f584..0000000000 --- a/third_party/libpng/pngtest.c +++ /dev/null @@ -1,2082 +0,0 @@ - -/* pngtest.c - a simple test program to test libpng - * - * Last changed in libpng 1.5.25 [December 3, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This program reads in a PNG image, writes it out again, and then - * compares the two files. If the files are identical, this shows that - * the basic chunk handling, filtering, and (de)compression code is working - * properly. It does not currently test all of the transforms, although - * it probably should. - * - * The program will report "FAIL" in certain legitimate cases: - * 1) when the compression level or filter selection method is changed. - * 2) when the maximum IDAT size (PNG_ZBUF_SIZE in pngconf.h) is not 8192. - * 3) unknown unsafe-to-copy ancillary chunks or unknown critical chunks - * exist in the input file. - * 4) others not listed here... - * In these cases, it is best to check with another tool such as "pngcheck" - * to see what the differences between the two files are. - * - * If a filename is given on the command-line, then this file is used - * for the input, rather than the default "pngtest.png". This allows - * testing a wide variety of files easily. You can also test a number - * of files at once by typing "pngtest -m file1.png file2.png ..." - */ - -#define _POSIX_SOURCE 1 - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> - -/* Defined so I can write to a file on gui/windowing platforms */ -/* #define STDERR stderr */ -#define STDERR stdout /* For DOS */ - -#include "png.h" - -/* 1.6.1 added support for the configure test harness, which uses 77 to indicate - * a skipped test, in earlier versions we need to succeed on a skipped test, so: - */ -#if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H) -# define SKIP 77 -#else -# define SKIP 0 -#endif - -/* Known chunks that exist in pngtest.png must be supported or pngtest will fail - * simply as a result of re-ordering them. This may be fixed in 1.7 - * - * pngtest allocates a single row buffer for each row and overwrites it, - * therefore if the write side doesn't support the writing of interlaced images - * nothing can be done for an interlaced image (and the code below will fail - * horribly trying to write extra data after writing garbage). - */ -#if defined PNG_READ_SUPPORTED && /* else nothing can be done */\ - defined PNG_READ_bKGD_SUPPORTED &&\ - defined PNG_READ_cHRM_SUPPORTED &&\ - defined PNG_READ_gAMA_SUPPORTED &&\ - defined PNG_READ_oFFs_SUPPORTED &&\ - defined PNG_READ_pCAL_SUPPORTED &&\ - defined PNG_READ_pHYs_SUPPORTED &&\ - defined PNG_READ_sBIT_SUPPORTED &&\ - defined PNG_READ_sCAL_SUPPORTED &&\ - defined PNG_READ_sRGB_SUPPORTED &&\ - defined PNG_READ_sPLT_SUPPORTED &&\ - defined PNG_READ_tEXt_SUPPORTED &&\ - defined PNG_READ_tIME_SUPPORTED &&\ - defined PNG_READ_zTXt_SUPPORTED &&\ - (defined PNG_WRITE_INTERLACING_SUPPORTED || PNG_LIBPNG_VER >= 10700) - -#ifdef PNG_ZLIB_HEADER -# include PNG_ZLIB_HEADER /* defined by pnglibconf.h from 1.7 */ -#else -# include "zlib.h" -#endif - -/* Copied from pngpriv.h but only used in error messages below. */ -#ifndef PNG_ZBUF_SIZE -# define PNG_ZBUF_SIZE 8192 -#endif -#define FCLOSE(file) fclose(file) - -#ifndef PNG_STDIO_SUPPORTED -typedef FILE * png_FILE_p; -#endif - -/* Makes pngtest verbose so we can find problems. */ -#ifndef PNG_DEBUG -# define PNG_DEBUG 0 -#endif - -#if PNG_DEBUG > 1 -# define pngtest_debug(m) ((void)fprintf(stderr, m "\n")) -# define pngtest_debug1(m,p1) ((void)fprintf(stderr, m "\n", p1)) -# define pngtest_debug2(m,p1,p2) ((void)fprintf(stderr, m "\n", p1, p2)) -#else -# define pngtest_debug(m) ((void)0) -# define pngtest_debug1(m,p1) ((void)0) -# define pngtest_debug2(m,p1,p2) ((void)0) -#endif - -#if !PNG_DEBUG -# define SINGLE_ROWBUF_ALLOC /* Makes buffer overruns easier to nail */ -#endif - -#ifndef PNG_UNUSED -# define PNG_UNUSED(param) (void)param; -#endif - -/* Turn on CPU timing -#define PNGTEST_TIMING -*/ - -#ifndef PNG_FLOATING_POINT_SUPPORTED -#undef PNGTEST_TIMING -#endif - -#ifdef PNGTEST_TIMING -static float t_start, t_stop, t_decode, t_encode, t_misc; -#include <time.h> -#endif - -#ifdef PNG_TIME_RFC1123_SUPPORTED -#define PNG_tIME_STRING_LENGTH 29 -static int tIME_chunk_present = 0; -static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present"; - -#if PNG_LIBPNG_VER < 10619 -#define png_convert_to_rfc1123_buffer(ts, t) tIME_to_str(read_ptr, ts, t) - -static int -tIME_to_str(png_structp png_ptr, png_charp ts, png_const_timep t) -{ - png_const_charp str = png_convert_to_rfc1123(png_ptr, t); - - if (str == NULL) - return 0; - - strcpy(ts, str); - return 1; -} -#endif /* older libpng */ -#endif - -static int verbose = 0; -static int strict = 0; -static int relaxed = 0; -static int unsupported_chunks = 0; /* chunk unsupported by libpng in input */ -static int error_count = 0; /* count calls to png_error */ -static int warning_count = 0; /* count calls to png_warning */ - -/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */ -#ifndef png_jmpbuf -# define png_jmpbuf(png_ptr) png_ptr->jmpbuf -#endif - -/* Defines for unknown chunk handling if required. */ -#ifndef PNG_HANDLE_CHUNK_ALWAYS -# define PNG_HANDLE_CHUNK_ALWAYS 3 -#endif -#ifndef PNG_HANDLE_CHUNK_IF_SAFE -# define PNG_HANDLE_CHUNK_IF_SAFE 2 -#endif - -/* Utility to save typing/errors, the argument must be a name */ -#define MEMZERO(var) ((void)memset(&var, 0, sizeof var)) - -/* Example of using row callbacks to make a simple progress meter */ -static int status_pass = 1; -static int status_dots_requested = 0; -static int status_dots = 1; - -static void PNGCBAPI -read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass) -{ - if (png_ptr == NULL || row_number > PNG_UINT_31_MAX) - return; - - if (status_pass != pass) - { - fprintf(stdout, "\n Pass %d: ", pass); - status_pass = pass; - status_dots = 31; - } - - status_dots--; - - if (status_dots == 0) - { - fprintf(stdout, "\n "); - status_dots=30; - } - - fprintf(stdout, "r"); -} - -#ifdef PNG_WRITE_SUPPORTED -static void PNGCBAPI -write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass) -{ - if (png_ptr == NULL || row_number > PNG_UINT_31_MAX || pass > 7) - return; - - fprintf(stdout, "w"); -} -#endif - - -#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED -/* Example of using a user transform callback (doesn't do anything at present). - */ -static void PNGCBAPI -read_user_callback(png_structp png_ptr, png_row_infop row_info, png_bytep data) -{ - PNG_UNUSED(png_ptr) - PNG_UNUSED(row_info) - PNG_UNUSED(data) -} -#endif - -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED -/* Example of using user transform callback (we don't transform anything, - * but merely count the zero samples) - */ - -static png_uint_32 zero_samples; - -static void PNGCBAPI -count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data) -{ - png_bytep dp = data; - if (png_ptr == NULL) - return; - - /* Contents of row_info: - * png_uint_32 width width of row - * png_uint_32 rowbytes number of bytes in row - * png_byte color_type color type of pixels - * png_byte bit_depth bit depth of samples - * png_byte channels number of channels (1-4) - * png_byte pixel_depth bits per pixel (depth*channels) - */ - - /* Counts the number of zero samples (or zero pixels if color_type is 3 */ - - if (row_info->color_type == 0 || row_info->color_type == 3) - { - int pos = 0; - png_uint_32 n, nstop; - - for (n = 0, nstop=row_info->width; n<nstop; n++) - { - if (row_info->bit_depth == 1) - { - if (((*dp << pos++ ) & 0x80) == 0) - zero_samples++; - - if (pos == 8) - { - pos = 0; - dp++; - } - } - - if (row_info->bit_depth == 2) - { - if (((*dp << (pos+=2)) & 0xc0) == 0) - zero_samples++; - - if (pos == 8) - { - pos = 0; - dp++; - } - } - - if (row_info->bit_depth == 4) - { - if (((*dp << (pos+=4)) & 0xf0) == 0) - zero_samples++; - - if (pos == 8) - { - pos = 0; - dp++; - } - } - - if (row_info->bit_depth == 8) - if (*dp++ == 0) - zero_samples++; - - if (row_info->bit_depth == 16) - { - if ((*dp | *(dp+1)) == 0) - zero_samples++; - dp+=2; - } - } - } - else /* Other color types */ - { - png_uint_32 n, nstop; - int channel; - int color_channels = row_info->channels; - if (row_info->color_type > 3) - color_channels--; - - for (n = 0, nstop=row_info->width; n<nstop; n++) - { - for (channel = 0; channel < color_channels; channel++) - { - if (row_info->bit_depth == 8) - if (*dp++ == 0) - zero_samples++; - - if (row_info->bit_depth == 16) - { - if ((*dp | *(dp+1)) == 0) - zero_samples++; - - dp+=2; - } - } - if (row_info->color_type > 3) - { - dp++; - if (row_info->bit_depth == 16) - dp++; - } - } - } -} -#endif /* WRITE_USER_TRANSFORM */ - -#ifndef PNG_STDIO_SUPPORTED -/* START of code to validate stdio-free compilation */ -/* These copies of the default read/write functions come from pngrio.c and - * pngwio.c. They allow "don't include stdio" testing of the library. - * This is the function that does the actual reading of data. If you are - * not reading from a standard C stream, you should create a replacement - * read_data function and use it at run time with png_set_read_fn(), rather - * than changing the library. - */ - -#ifdef PNG_IO_STATE_SUPPORTED -void -pngtest_check_io_state(png_structp png_ptr, png_size_t data_length, - png_uint_32 io_op); -void -pngtest_check_io_state(png_structp png_ptr, png_size_t data_length, - png_uint_32 io_op) -{ - png_uint_32 io_state = png_get_io_state(png_ptr); - int err = 0; - - /* Check if the current operation (reading / writing) is as expected. */ - if ((io_state & PNG_IO_MASK_OP) != io_op) - png_error(png_ptr, "Incorrect operation in I/O state"); - - /* Check if the buffer size specific to the current location - * (file signature / header / data / crc) is as expected. - */ - switch (io_state & PNG_IO_MASK_LOC) - { - case PNG_IO_SIGNATURE: - if (data_length > 8) - err = 1; - break; - case PNG_IO_CHUNK_HDR: - if (data_length != 8) - err = 1; - break; - case PNG_IO_CHUNK_DATA: - break; /* no restrictions here */ - case PNG_IO_CHUNK_CRC: - if (data_length != 4) - err = 1; - break; - default: - err = 1; /* uninitialized */ - } - if (err != 0) - png_error(png_ptr, "Bad I/O state or buffer size"); -} -#endif - -static void PNGCBAPI -pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length) -{ - png_size_t check = 0; - png_voidp io_ptr; - - /* fread() returns 0 on error, so it is OK to store this in a png_size_t - * instead of an int, which is what fread() actually returns. - */ - io_ptr = png_get_io_ptr(png_ptr); - if (io_ptr != NULL) - { - check = fread(data, 1, length, (png_FILE_p)io_ptr); - } - - if (check != length) - { - png_error(png_ptr, "Read Error"); - } - -#ifdef PNG_IO_STATE_SUPPORTED - pngtest_check_io_state(png_ptr, length, PNG_IO_READING); -#endif -} - -#ifdef PNG_WRITE_FLUSH_SUPPORTED -static void PNGCBAPI -pngtest_flush(png_structp png_ptr) -{ - /* Do nothing; fflush() is said to be just a waste of energy. */ - PNG_UNUSED(png_ptr) /* Stifle compiler warning */ -} -#endif - -/* This is the function that does the actual writing of data. If you are - * not writing to a standard C stream, you should create a replacement - * write_data function and use it at run time with png_set_write_fn(), rather - * than changing the library. - */ -static void PNGCBAPI -pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length) -{ - png_size_t check; - - check = fwrite(data, 1, length, (png_FILE_p)png_get_io_ptr(png_ptr)); - - if (check != length) - { - png_error(png_ptr, "Write Error"); - } - -#ifdef PNG_IO_STATE_SUPPORTED - pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING); -#endif -} -#endif /* !STDIO */ - -/* This function is called when there is a warning, but the library thinks - * it can continue anyway. Replacement functions don't have to do anything - * here if you don't want to. In the default configuration, png_ptr is - * not used, but it is passed in case it may be useful. - */ -typedef struct -{ - PNG_CONST char *file_name; -} pngtest_error_parameters; - -static void PNGCBAPI -pngtest_warning(png_structp png_ptr, png_const_charp message) -{ - PNG_CONST char *name = "UNKNOWN (ERROR!)"; - pngtest_error_parameters *test = - (pngtest_error_parameters*)png_get_error_ptr(png_ptr); - - ++warning_count; - - if (test != NULL && test->file_name != NULL) - name = test->file_name; - - fprintf(STDERR, "%s: libpng warning: %s\n", name, message); -} - -/* This is the default error handling function. Note that replacements for - * this function MUST NOT RETURN, or the program will likely crash. This - * function is used by default, or if the program supplies NULL for the - * error function pointer in png_set_error_fn(). - */ -static void PNGCBAPI -pngtest_error(png_structp png_ptr, png_const_charp message) -{ - ++error_count; - - pngtest_warning(png_ptr, message); - /* We can return because png_error calls the default handler, which is - * actually OK in this case. - */ -} - -/* END of code to validate stdio-free compilation */ - -/* START of code to validate memory allocation and deallocation */ -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - -/* Allocate memory. For reasonable files, size should never exceed - * 64K. However, zlib may allocate more than 64K if you don't tell - * it not to. See zconf.h and png.h for more information. zlib does - * need to allocate exactly 64K, so whatever you call here must - * have the ability to do that. - * - * This piece of code can be compiled to validate max 64K allocations - * by setting MAXSEG_64K in zlib zconf.h *or* PNG_MAX_MALLOC_64K. - */ -typedef struct memory_information -{ - png_alloc_size_t size; - png_voidp pointer; - struct memory_information *next; -} memory_information; -typedef memory_information *memory_infop; - -static memory_infop pinformation = NULL; -static int current_allocation = 0; -static int maximum_allocation = 0; -static int total_allocation = 0; -static int num_allocations = 0; - -png_voidp PNGCBAPI png_debug_malloc PNGARG((png_structp png_ptr, - png_alloc_size_t size)); -void PNGCBAPI png_debug_free PNGARG((png_structp png_ptr, png_voidp ptr)); - -png_voidp -PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size) -{ - - /* png_malloc has already tested for NULL; png_create_struct calls - * png_debug_malloc directly, with png_ptr == NULL which is OK - */ - - if (size == 0) - return (NULL); - - /* This calls the library allocator twice, once to get the requested - buffer and once to get a new free list entry. */ - { - /* Disable malloc_fn and free_fn */ - memory_infop pinfo; - png_set_mem_fn(png_ptr, NULL, NULL, NULL); - pinfo = (memory_infop)png_malloc(png_ptr, - (sizeof *pinfo)); - pinfo->size = size; - current_allocation += size; - total_allocation += size; - num_allocations ++; - - if (current_allocation > maximum_allocation) - maximum_allocation = current_allocation; - - pinfo->pointer = png_malloc(png_ptr, size); - /* Restore malloc_fn and free_fn */ - - png_set_mem_fn(png_ptr, - NULL, png_debug_malloc, png_debug_free); - - if (size != 0 && pinfo->pointer == NULL) - { - current_allocation -= size; - total_allocation -= size; - png_error(png_ptr, - "out of memory in pngtest->png_debug_malloc"); - } - - pinfo->next = pinformation; - pinformation = pinfo; - /* Make sure the caller isn't assuming zeroed memory. */ - memset(pinfo->pointer, 0xdd, pinfo->size); - - if (verbose != 0) - printf("png_malloc %lu bytes at %p\n", (unsigned long)size, - pinfo->pointer); - - return (png_voidp)(pinfo->pointer); - } -} - -/* Free a pointer. It is removed from the list at the same time. */ -void PNGCBAPI -png_debug_free(png_structp png_ptr, png_voidp ptr) -{ - if (png_ptr == NULL) - fprintf(STDERR, "NULL pointer to png_debug_free.\n"); - - if (ptr == 0) - { -#if 0 /* This happens all the time. */ - fprintf(STDERR, "WARNING: freeing NULL pointer\n"); -#endif - return; - } - - /* Unlink the element from the list. */ - if (pinformation != NULL) - { - memory_infop *ppinfo = &pinformation; - - for (;;) - { - memory_infop pinfo = *ppinfo; - - if (pinfo->pointer == ptr) - { - *ppinfo = pinfo->next; - current_allocation -= pinfo->size; - if (current_allocation < 0) - fprintf(STDERR, "Duplicate free of memory\n"); - /* We must free the list element too, but first kill - the memory that is to be freed. */ - memset(ptr, 0x55, pinfo->size); - free(pinfo); - pinfo = NULL; - break; - } - - if (pinfo->next == NULL) - { - fprintf(STDERR, "Pointer %p not found\n", ptr); - break; - } - - ppinfo = &pinfo->next; - } - } - - /* Finally free the data. */ - if (verbose != 0) - printf("Freeing %p\n", ptr); - - if (ptr != NULL) - free(ptr); - ptr = NULL; -} -#endif /* USER_MEM && DEBUG */ -/* END of code to test memory allocation/deallocation */ - - -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED -/* Demonstration of user chunk support of the sTER and vpAg chunks */ - -/* (sTER is a public chunk not yet known by libpng. vpAg is a private -chunk used in ImageMagick to store "virtual page" size). */ - -static struct user_chunk_data -{ - png_const_infop info_ptr; - png_uint_32 vpAg_width, vpAg_height; - png_byte vpAg_units; - png_byte sTER_mode; - int location[2]; -} -user_chunk_data; - -/* Used for location and order; zero means nothing. */ -#define have_sTER 0x01 -#define have_vpAg 0x02 -#define before_PLTE 0x10 -#define before_IDAT 0x20 -#define after_IDAT 0x40 - -static void -init_callback_info(png_const_infop info_ptr) -{ - MEMZERO(user_chunk_data); - user_chunk_data.info_ptr = info_ptr; -} - -static int -set_location(png_structp png_ptr, struct user_chunk_data *data, int what) -{ - int location; - - if ((data->location[0] & what) != 0 || (data->location[1] & what) != 0) - return 0; /* already have one of these */ - - /* Find where we are (the code below zeroes info_ptr to indicate that the - * chunks before the first IDAT have been read.) - */ - if (data->info_ptr == NULL) /* after IDAT */ - location = what | after_IDAT; - - else if (png_get_valid(png_ptr, data->info_ptr, PNG_INFO_PLTE) != 0) - location = what | before_IDAT; - - else - location = what | before_PLTE; - - if (data->location[0] == 0) - data->location[0] = location; - - else - data->location[1] = location; - - return 1; /* handled */ -} - -static int PNGCBAPI -read_user_chunk_callback(png_struct *png_ptr, png_unknown_chunkp chunk) -{ - struct user_chunk_data *my_user_chunk_data = - (struct user_chunk_data*)png_get_user_chunk_ptr(png_ptr); - - if (my_user_chunk_data == NULL) - png_error(png_ptr, "lost user chunk pointer"); - - /* Return one of the following: - * return (-n); chunk had an error - * return (0); did not recognize - * return (n); success - * - * The unknown chunk structure contains the chunk data: - * png_byte name[5]; - * png_byte *data; - * png_size_t size; - * - * Note that libpng has already taken care of the CRC handling. - */ - - if (chunk->name[0] == 115 && chunk->name[1] == 84 && /* s T */ - chunk->name[2] == 69 && chunk->name[3] == 82) /* E R */ - { - /* Found sTER chunk */ - if (chunk->size != 1) - return (-1); /* Error return */ - - if (chunk->data[0] != 0 && chunk->data[0] != 1) - return (-1); /* Invalid mode */ - - if (set_location(png_ptr, my_user_chunk_data, have_sTER) != 0) - { - my_user_chunk_data->sTER_mode=chunk->data[0]; - return (1); - } - - else - return (0); /* duplicate sTER - give it to libpng */ - } - - if (chunk->name[0] != 118 || chunk->name[1] != 112 || /* v p */ - chunk->name[2] != 65 || chunk->name[3] != 103) /* A g */ - return (0); /* Did not recognize */ - - /* Found ImageMagick vpAg chunk */ - - if (chunk->size != 9) - return (-1); /* Error return */ - - if (set_location(png_ptr, my_user_chunk_data, have_vpAg) == 0) - return (0); /* duplicate vpAg */ - - my_user_chunk_data->vpAg_width = png_get_uint_31(png_ptr, chunk->data); - my_user_chunk_data->vpAg_height = png_get_uint_31(png_ptr, chunk->data + 4); - my_user_chunk_data->vpAg_units = chunk->data[8]; - - return (1); -} - -#ifdef PNG_WRITE_SUPPORTED -static void -write_sTER_chunk(png_structp write_ptr) -{ - png_byte sTER[5] = {115, 84, 69, 82, '\0'}; - - if (verbose != 0) - fprintf(STDERR, "\n stereo mode = %d\n", user_chunk_data.sTER_mode); - - png_write_chunk(write_ptr, sTER, &user_chunk_data.sTER_mode, 1); -} - -static void -write_vpAg_chunk(png_structp write_ptr) -{ - png_byte vpAg[5] = {118, 112, 65, 103, '\0'}; - - png_byte vpag_chunk_data[9]; - - if (verbose != 0) - fprintf(STDERR, " vpAg = %lu x %lu, units = %d\n", - (unsigned long)user_chunk_data.vpAg_width, - (unsigned long)user_chunk_data.vpAg_height, - user_chunk_data.vpAg_units); - - png_save_uint_32(vpag_chunk_data, user_chunk_data.vpAg_width); - png_save_uint_32(vpag_chunk_data + 4, user_chunk_data.vpAg_height); - vpag_chunk_data[8] = user_chunk_data.vpAg_units; - png_write_chunk(write_ptr, vpAg, vpag_chunk_data, 9); -} - -static void -write_chunks(png_structp write_ptr, int location) -{ - int i; - - /* Notice that this preserves the original chunk order, however chunks - * intercepted by the callback will be written *after* chunks passed to - * libpng. This will actually reverse a pair of sTER chunks or a pair of - * vpAg chunks, resulting in an error later. This is not worth worrying - * about - the chunks should not be duplicated! - */ - for (i=0; i<2; ++i) - { - if (user_chunk_data.location[i] == (location | have_sTER)) - write_sTER_chunk(write_ptr); - - else if (user_chunk_data.location[i] == (location | have_vpAg)) - write_vpAg_chunk(write_ptr); - } -} -#endif /* WRITE */ -#else /* !READ_USER_CHUNKS */ -# define write_chunks(pp,loc) ((void)0) -#endif -/* END of code to demonstrate user chunk support */ - -/* START of code to check that libpng has the required text support; this only - * checks for the write support because if read support is missing the chunk - * will simply not be reported back to pngtest. - */ -#ifdef PNG_TEXT_SUPPORTED -static void -pngtest_check_text_support(png_structp png_ptr, png_textp text_ptr, - int num_text) -{ - while (num_text > 0) - { - switch (text_ptr[--num_text].compression) - { - case PNG_TEXT_COMPRESSION_NONE: - break; - - case PNG_TEXT_COMPRESSION_zTXt: -# ifndef PNG_WRITE_zTXt_SUPPORTED - ++unsupported_chunks; - /* In libpng 1.7 this now does an app-error, so stop it: */ - text_ptr[num_text].compression = PNG_TEXT_COMPRESSION_NONE; -# endif - break; - - case PNG_ITXT_COMPRESSION_NONE: - case PNG_ITXT_COMPRESSION_zTXt: -# ifndef PNG_WRITE_iTXt_SUPPORTED - ++unsupported_chunks; - text_ptr[num_text].compression = PNG_TEXT_COMPRESSION_NONE; -# endif - break; - - default: - /* This is an error */ - png_error(png_ptr, "invalid text chunk compression field"); - break; - } - } -} -#endif -/* END of code to check that libpng has the required text support */ - -/* Test one file */ -static int -test_one_file(PNG_CONST char *inname, PNG_CONST char *outname) -{ - static png_FILE_p fpin; - static png_FILE_p fpout; /* "static" prevents setjmp corruption */ - pngtest_error_parameters error_parameters; - png_structp read_ptr; - png_infop read_info_ptr, end_info_ptr; -#ifdef PNG_WRITE_SUPPORTED - png_structp write_ptr; - png_infop write_info_ptr; - png_infop write_end_info_ptr; -#ifdef PNG_WRITE_FILTER_SUPPORTED - int interlace_preserved = 1; -#endif /* WRITE_FILTER */ -#else /* !WRITE */ - png_structp write_ptr = NULL; - png_infop write_info_ptr = NULL; - png_infop write_end_info_ptr = NULL; -#endif /* !WRITE */ - png_bytep row_buf; - png_uint_32 y; - png_uint_32 width, height; - volatile int num_passes; - int pass; - int bit_depth, color_type; - - row_buf = NULL; - error_parameters.file_name = inname; - - if ((fpin = fopen(inname, "rb")) == NULL) - { - fprintf(STDERR, "Could not find input file %s\n", inname); - return (1); - } - - if ((fpout = fopen(outname, "wb")) == NULL) - { - fprintf(STDERR, "Could not open output file %s\n", outname); - FCLOSE(fpin); - return (1); - } - - pngtest_debug("Allocating read and write structures"); -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - read_ptr = - png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL, - NULL, NULL, NULL, png_debug_malloc, png_debug_free); -#else - read_ptr = - png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); -#endif - png_set_error_fn(read_ptr, &error_parameters, pngtest_error, - pngtest_warning); - -#ifdef PNG_WRITE_SUPPORTED -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - write_ptr = - png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL, - NULL, NULL, NULL, png_debug_malloc, png_debug_free); -#else - write_ptr = - png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); -#endif - png_set_error_fn(write_ptr, &error_parameters, pngtest_error, - pngtest_warning); -#endif - pngtest_debug("Allocating read_info, write_info and end_info structures"); - read_info_ptr = png_create_info_struct(read_ptr); - end_info_ptr = png_create_info_struct(read_ptr); -#ifdef PNG_WRITE_SUPPORTED - write_info_ptr = png_create_info_struct(write_ptr); - write_end_info_ptr = png_create_info_struct(write_ptr); -#endif - -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED - init_callback_info(read_info_ptr); - png_set_read_user_chunk_fn(read_ptr, &user_chunk_data, - read_user_chunk_callback); -#endif - -#ifdef PNG_SETJMP_SUPPORTED - pngtest_debug("Setting jmpbuf for read struct"); - if (setjmp(png_jmpbuf(read_ptr))) - { - fprintf(STDERR, "%s -> %s: libpng read error\n", inname, outname); - png_free(read_ptr, row_buf); - row_buf = NULL; - png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); -#ifdef PNG_WRITE_SUPPORTED - png_destroy_info_struct(write_ptr, &write_end_info_ptr); - png_destroy_write_struct(&write_ptr, &write_info_ptr); -#endif - FCLOSE(fpin); - FCLOSE(fpout); - return (1); - } - -#ifdef PNG_WRITE_SUPPORTED - pngtest_debug("Setting jmpbuf for write struct"); - - if (setjmp(png_jmpbuf(write_ptr))) - { - fprintf(STDERR, "%s -> %s: libpng write error\n", inname, outname); - png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); - png_destroy_info_struct(write_ptr, &write_end_info_ptr); -#ifdef PNG_WRITE_SUPPORTED - png_destroy_write_struct(&write_ptr, &write_info_ptr); -#endif - FCLOSE(fpin); - FCLOSE(fpout); - return (1); - } -#endif -#endif - - if (strict != 0) - { - /* Treat png_benign_error() as errors on read */ - png_set_benign_errors(read_ptr, 0); - -#ifdef PNG_WRITE_SUPPORTED - /* Treat them as errors on write */ - png_set_benign_errors(write_ptr, 0); -#endif - - /* if strict is not set, then app warnings and errors are treated as - * warnings in release builds, but not in unstable builds; this can be - * changed with '--relaxed'. - */ - } - - else if (relaxed != 0) - { - /* Allow application (pngtest) errors and warnings to pass */ - png_set_benign_errors(read_ptr, 1); - -#ifdef PNG_WRITE_SUPPORTED - png_set_benign_errors(write_ptr, 1); -#endif - } - - pngtest_debug("Initializing input and output streams"); -#ifdef PNG_STDIO_SUPPORTED - png_init_io(read_ptr, fpin); -# ifdef PNG_WRITE_SUPPORTED - png_init_io(write_ptr, fpout); -# endif -#else - png_set_read_fn(read_ptr, (png_voidp)fpin, pngtest_read_data); -# ifdef PNG_WRITE_SUPPORTED - png_set_write_fn(write_ptr, (png_voidp)fpout, pngtest_write_data, -# ifdef PNG_WRITE_FLUSH_SUPPORTED - pngtest_flush); -# else - NULL); -# endif -# endif -#endif - - if (status_dots_requested == 1) - { -#ifdef PNG_WRITE_SUPPORTED - png_set_write_status_fn(write_ptr, write_row_callback); -#endif - png_set_read_status_fn(read_ptr, read_row_callback); - } - - else - { -#ifdef PNG_WRITE_SUPPORTED - png_set_write_status_fn(write_ptr, NULL); -#endif - png_set_read_status_fn(read_ptr, NULL); - } - -#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED - png_set_read_user_transform_fn(read_ptr, read_user_callback); -#endif -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED - zero_samples = 0; - png_set_write_user_transform_fn(write_ptr, count_zero_samples); -#endif - -#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED - /* Preserve all the unknown chunks, if possible. If this is disabled then, - * even if the png_{get,set}_unknown_chunks stuff is enabled, we can't use - * libpng to *save* the unknown chunks on read (because we can't switch the - * save option on!) - * - * Notice that if SET_UNKNOWN_CHUNKS is *not* supported read will discard all - * unknown chunks and write will write them all. - */ -#ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED - png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS, - NULL, 0); -#endif -#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS, - NULL, 0); -#endif -#endif - - pngtest_debug("Reading info struct"); - png_read_info(read_ptr, read_info_ptr); - -#ifdef PNG_READ_USER_CHUNKS_SUPPORTED - /* This is a bit of a hack; there is no obvious way in the callback function - * to determine that the chunks before the first IDAT have been read, so - * remove the info_ptr (which is only used to determine position relative to - * PLTE) here to indicate that we are after the IDAT. - */ - user_chunk_data.info_ptr = NULL; -#endif - - pngtest_debug("Transferring info struct"); - { - int interlace_type, compression_type, filter_type; - - if (png_get_IHDR(read_ptr, read_info_ptr, &width, &height, &bit_depth, - &color_type, &interlace_type, &compression_type, &filter_type) != 0) - { - png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth, - color_type, interlace_type, compression_type, filter_type); - /* num_passes may not be available below if interlace support is not - * provided by libpng for both read and write. - */ - switch (interlace_type) - { - case PNG_INTERLACE_NONE: - num_passes = 1; - break; - - case PNG_INTERLACE_ADAM7: - num_passes = 7; - break; - - default: - png_error(read_ptr, "invalid interlace type"); - /*NOT REACHED*/ - } - } - - else - png_error(read_ptr, "png_get_IHDR failed"); - } -#ifdef PNG_FIXED_POINT_SUPPORTED -#ifdef PNG_cHRM_SUPPORTED - { - png_fixed_point white_x, white_y, red_x, red_y, green_x, green_y, blue_x, - blue_y; - - if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y, - &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0) - { - png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x, - red_y, green_x, green_y, blue_x, blue_y); - } - } -#endif -#ifdef PNG_gAMA_SUPPORTED - { - png_fixed_point gamma; - - if (png_get_gAMA_fixed(read_ptr, read_info_ptr, &gamma) != 0) - png_set_gAMA_fixed(write_ptr, write_info_ptr, gamma); - } -#endif -#else /* Use floating point versions */ -#ifdef PNG_FLOATING_POINT_SUPPORTED -#ifdef PNG_cHRM_SUPPORTED - { - double white_x, white_y, red_x, red_y, green_x, green_y, blue_x, - blue_y; - - if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x, - &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0) - { - png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x, - red_y, green_x, green_y, blue_x, blue_y); - } - } -#endif -#ifdef PNG_gAMA_SUPPORTED - { - double gamma; - - if (png_get_gAMA(read_ptr, read_info_ptr, &gamma) != 0) - png_set_gAMA(write_ptr, write_info_ptr, gamma); - } -#endif -#endif /* Floating point */ -#endif /* Fixed point */ -#ifdef PNG_iCCP_SUPPORTED - { - png_charp name; - png_bytep profile; - png_uint_32 proflen; - int compression_type; - - if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type, - &profile, &proflen) != 0) - { - png_set_iCCP(write_ptr, write_info_ptr, name, compression_type, - profile, proflen); - } - } -#endif -#ifdef PNG_sRGB_SUPPORTED - { - int intent; - - if (png_get_sRGB(read_ptr, read_info_ptr, &intent) != 0) - png_set_sRGB(write_ptr, write_info_ptr, intent); - } -#endif - { - png_colorp palette; - int num_palette; - - if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette) != 0) - png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette); - } -#ifdef PNG_bKGD_SUPPORTED - { - png_color_16p background; - - if (png_get_bKGD(read_ptr, read_info_ptr, &background) != 0) - { - png_set_bKGD(write_ptr, write_info_ptr, background); - } - } -#endif -#ifdef PNG_hIST_SUPPORTED - { - png_uint_16p hist; - - if (png_get_hIST(read_ptr, read_info_ptr, &hist) != 0) - png_set_hIST(write_ptr, write_info_ptr, hist); - } -#endif -#ifdef PNG_oFFs_SUPPORTED - { - png_int_32 offset_x, offset_y; - int unit_type; - - if (png_get_oFFs(read_ptr, read_info_ptr, &offset_x, &offset_y, - &unit_type) != 0) - { - png_set_oFFs(write_ptr, write_info_ptr, offset_x, offset_y, unit_type); - } - } -#endif -#ifdef PNG_pCAL_SUPPORTED - { - png_charp purpose, units; - png_charpp params; - png_int_32 X0, X1; - int type, nparams; - - if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type, - &nparams, &units, ¶ms) != 0) - { - png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type, - nparams, units, params); - } - } -#endif -#ifdef PNG_pHYs_SUPPORTED - { - png_uint_32 res_x, res_y; - int unit_type; - - if (png_get_pHYs(read_ptr, read_info_ptr, &res_x, &res_y, - &unit_type) != 0) - png_set_pHYs(write_ptr, write_info_ptr, res_x, res_y, unit_type); - } -#endif -#ifdef PNG_sBIT_SUPPORTED - { - png_color_8p sig_bit; - - if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit) != 0) - png_set_sBIT(write_ptr, write_info_ptr, sig_bit); - } -#endif -#ifdef PNG_sCAL_SUPPORTED -#if defined(PNG_FLOATING_POINT_SUPPORTED) && \ - defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) - { - int unit; - double scal_width, scal_height; - - if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &scal_width, - &scal_height) != 0) - { - png_set_sCAL(write_ptr, write_info_ptr, unit, scal_width, scal_height); - } - } -#else -#ifdef PNG_FIXED_POINT_SUPPORTED - { - int unit; - png_charp scal_width, scal_height; - - if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &scal_width, - &scal_height) != 0) - { - png_set_sCAL_s(write_ptr, write_info_ptr, unit, scal_width, - scal_height); - } - } -#endif -#endif -#endif - -#ifdef PNG_sPLT_SUPPORTED - { - png_sPLT_tp entries; - - int num_entries = (int) png_get_sPLT(read_ptr, read_info_ptr, &entries); - if (num_entries) - { - png_set_sPLT(write_ptr, write_info_ptr, entries, num_entries); - } - } -#endif - -#ifdef PNG_TEXT_SUPPORTED - { - png_textp text_ptr; - int num_text; - - if (png_get_text(read_ptr, read_info_ptr, &text_ptr, &num_text) > 0) - { - pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text); - - pngtest_check_text_support(read_ptr, text_ptr, num_text); - - if (verbose != 0) - { - int i; - - printf("\n"); - for (i=0; i<num_text; i++) - { - printf(" Text compression[%d]=%d\n", - i, text_ptr[i].compression); - } - } - - png_set_text(write_ptr, write_info_ptr, text_ptr, num_text); - } - } -#endif -#ifdef PNG_tIME_SUPPORTED - { - png_timep mod_time; - - if (png_get_tIME(read_ptr, read_info_ptr, &mod_time) != 0) - { - png_set_tIME(write_ptr, write_info_ptr, mod_time); -#ifdef PNG_TIME_RFC1123_SUPPORTED - if (png_convert_to_rfc1123_buffer(tIME_string, mod_time) != 0) - tIME_string[(sizeof tIME_string) - 1] = '\0'; - - else - { - strncpy(tIME_string, "*** invalid time ***", (sizeof tIME_string)); - tIME_string[(sizeof tIME_string) - 1] = '\0'; - } - - tIME_chunk_present++; -#endif /* TIME_RFC1123 */ - } - } -#endif -#ifdef PNG_tRNS_SUPPORTED - { - png_bytep trans_alpha; - int num_trans; - png_color_16p trans_color; - - if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans, - &trans_color) != 0) - { - int sample_max = (1 << bit_depth); - /* libpng doesn't reject a tRNS chunk with out-of-range samples */ - if (!((color_type == PNG_COLOR_TYPE_GRAY && - (int)trans_color->gray > sample_max) || - (color_type == PNG_COLOR_TYPE_RGB && - ((int)trans_color->red > sample_max || - (int)trans_color->green > sample_max || - (int)trans_color->blue > sample_max)))) - png_set_tRNS(write_ptr, write_info_ptr, trans_alpha, num_trans, - trans_color); - } - } -#endif -#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - { - png_unknown_chunkp unknowns; - int num_unknowns = png_get_unknown_chunks(read_ptr, read_info_ptr, - &unknowns); - - if (num_unknowns != 0) - { - png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns, - num_unknowns); -#if PNG_LIBPNG_VER < 10600 - /* Copy the locations from the read_info_ptr. The automatically - * generated locations in write_end_info_ptr are wrong prior to 1.6.0 - * because they are reset from the write pointer (removed in 1.6.0). - */ - { - int i; - for (i = 0; i < num_unknowns; i++) - png_set_unknown_chunk_location(write_ptr, write_info_ptr, i, - unknowns[i].location); - } -#endif - } - } -#endif - -#ifdef PNG_WRITE_SUPPORTED - pngtest_debug("Writing info struct"); - - /* Write the info in two steps so that if we write the 'unknown' chunks here - * they go to the correct place. - */ - png_write_info_before_PLTE(write_ptr, write_info_ptr); - - write_chunks(write_ptr, before_PLTE); /* before PLTE */ - - png_write_info(write_ptr, write_info_ptr); - - write_chunks(write_ptr, before_IDAT); /* after PLTE */ -#endif - -#ifdef SINGLE_ROWBUF_ALLOC - pngtest_debug("Allocating row buffer..."); - row_buf = (png_bytep)png_malloc(read_ptr, - png_get_rowbytes(read_ptr, read_info_ptr)); - - pngtest_debug1("\t0x%08lx", (unsigned long)row_buf); -#endif /* SINGLE_ROWBUF_ALLOC */ - pngtest_debug("Writing row data"); - -#if defined(PNG_READ_INTERLACING_SUPPORTED) &&\ - defined(PNG_WRITE_INTERLACING_SUPPORTED) - /* Both must be defined for libpng to be able to handle the interlace, - * otherwise it gets handled below by simply reading and writing the passes - * directly. - */ - if (png_set_interlace_handling(read_ptr) != num_passes) - png_error(write_ptr, - "png_set_interlace_handling(read): wrong pass count "); - if (png_set_interlace_handling(write_ptr) != num_passes) - png_error(write_ptr, - "png_set_interlace_handling(write): wrong pass count "); -#else /* png_set_interlace_handling not called on either read or write */ -# define calc_pass_height -#endif /* not using libpng interlace handling */ - -#ifdef PNGTEST_TIMING - t_stop = (float)clock(); - t_misc += (t_stop - t_start); - t_start = t_stop; -#endif - for (pass = 0; pass < num_passes; pass++) - { -# ifdef calc_pass_height - png_uint_32 pass_height; - - if (num_passes == 7) /* interlaced */ - { - if (PNG_PASS_COLS(width, pass) > 0) - pass_height = PNG_PASS_ROWS(height, pass); - - else - pass_height = 0; - } - - else /* not interlaced */ - pass_height = height; -# else -# define pass_height height -# endif - - pngtest_debug1("Writing row data for pass %d", pass); - for (y = 0; y < pass_height; y++) - { -#ifndef SINGLE_ROWBUF_ALLOC - pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y); - - row_buf = (png_bytep)png_malloc(read_ptr, - png_get_rowbytes(read_ptr, read_info_ptr)); - - pngtest_debug2("\t0x%08lx (%lu bytes)", (unsigned long)row_buf, - (unsigned long)png_get_rowbytes(read_ptr, read_info_ptr)); - -#endif /* !SINGLE_ROWBUF_ALLOC */ - png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1); - -#ifdef PNG_WRITE_SUPPORTED -#ifdef PNGTEST_TIMING - t_stop = (float)clock(); - t_decode += (t_stop - t_start); - t_start = t_stop; -#endif - png_write_rows(write_ptr, (png_bytepp)&row_buf, 1); -#ifdef PNGTEST_TIMING - t_stop = (float)clock(); - t_encode += (t_stop - t_start); - t_start = t_stop; -#endif -#endif /* WRITE */ - -#ifndef SINGLE_ROWBUF_ALLOC - pngtest_debug2("Freeing row buffer (pass %d, y = %u)", pass, y); - png_free(read_ptr, row_buf); - row_buf = NULL; -#endif /* !SINGLE_ROWBUF_ALLOC */ - } - } - -#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED -# ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED - png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1); -# endif -# ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1); -# endif -#endif - - pngtest_debug("Reading and writing end_info data"); - - png_read_end(read_ptr, end_info_ptr); -#ifdef PNG_TEXT_SUPPORTED - { - png_textp text_ptr; - int num_text; - - if (png_get_text(read_ptr, end_info_ptr, &text_ptr, &num_text) > 0) - { - pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text); - - pngtest_check_text_support(read_ptr, text_ptr, num_text); - - if (verbose != 0) - { - int i; - - printf("\n"); - for (i=0; i<num_text; i++) - { - printf(" Text compression[%d]=%d\n", - i, text_ptr[i].compression); - } - } - - png_set_text(write_ptr, write_end_info_ptr, text_ptr, num_text); - } - } -#endif -#ifdef PNG_tIME_SUPPORTED - { - png_timep mod_time; - - if (png_get_tIME(read_ptr, end_info_ptr, &mod_time) != 0) - { - png_set_tIME(write_ptr, write_end_info_ptr, mod_time); -#ifdef PNG_TIME_RFC1123_SUPPORTED - if (png_convert_to_rfc1123_buffer(tIME_string, mod_time) != 0) - tIME_string[(sizeof tIME_string) - 1] = '\0'; - - else - { - strncpy(tIME_string, "*** invalid time ***", sizeof tIME_string); - tIME_string[(sizeof tIME_string)-1] = '\0'; - } - - tIME_chunk_present++; -#endif /* TIME_RFC1123 */ - } - } -#endif -#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - { - png_unknown_chunkp unknowns; - int num_unknowns = png_get_unknown_chunks(read_ptr, end_info_ptr, - &unknowns); - - if (num_unknowns != 0) - { - png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns, - num_unknowns); -#if PNG_LIBPNG_VER < 10600 - /* Copy the locations from the read_info_ptr. The automatically - * generated locations in write_end_info_ptr are wrong prior to 1.6.0 - * because they are reset from the write pointer (removed in 1.6.0). - */ - { - int i; - for (i = 0; i < num_unknowns; i++) - png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i, - unknowns[i].location); - } -#endif - } - } -#endif - -#ifdef PNG_WRITE_SUPPORTED -#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED - /* Normally one would use Z_DEFAULT_STRATEGY for text compression. - * This is here just to make pngtest replicate the results from libpng - * versions prior to 1.5.4, and to test this new API. - */ - png_set_text_compression_strategy(write_ptr, Z_FILTERED); -#endif - - /* When the unknown vpAg/sTER chunks are written by pngtest the only way to - * do it is to write them *before* calling png_write_end. When unknown - * chunks are written by libpng, however, they are written just before IEND. - * There seems to be no way round this, however vpAg/sTER are not expected - * after IDAT. - */ - write_chunks(write_ptr, after_IDAT); - - png_write_end(write_ptr, write_end_info_ptr); -#endif - -#ifdef PNG_EASY_ACCESS_SUPPORTED - if (verbose != 0) - { - png_uint_32 iwidth, iheight; - iwidth = png_get_image_width(write_ptr, write_info_ptr); - iheight = png_get_image_height(write_ptr, write_info_ptr); - fprintf(STDERR, "\n Image width = %lu, height = %lu\n", - (unsigned long)iwidth, (unsigned long)iheight); - } -#endif - - pngtest_debug("Destroying data structs"); -#ifdef SINGLE_ROWBUF_ALLOC - pngtest_debug("destroying row_buf for read_ptr"); - png_free(read_ptr, row_buf); - row_buf = NULL; -#endif /* SINGLE_ROWBUF_ALLOC */ - pngtest_debug("destroying read_ptr, read_info_ptr, end_info_ptr"); - png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); -#ifdef PNG_WRITE_SUPPORTED - pngtest_debug("destroying write_end_info_ptr"); - png_destroy_info_struct(write_ptr, &write_end_info_ptr); - pngtest_debug("destroying write_ptr, write_info_ptr"); - png_destroy_write_struct(&write_ptr, &write_info_ptr); -#endif - pngtest_debug("Destruction complete."); - - FCLOSE(fpin); - FCLOSE(fpout); - - /* Summarize any warnings or errors and in 'strict' mode fail the test. - * Unsupported chunks can result in warnings, in that case ignore the strict - * setting, otherwise fail the test on warnings as well as errors. - */ - if (error_count > 0) - { - /* We don't really expect to get here because of the setjmp handling - * above, but this is safe. - */ - fprintf(STDERR, "\n %s: %d libpng errors found (%d warnings)", - inname, error_count, warning_count); - - if (strict != 0) - return (1); - } - -# ifdef PNG_WRITE_SUPPORTED - /* If there is no write support nothing was written! */ - else if (unsupported_chunks > 0) - { - fprintf(STDERR, "\n %s: unsupported chunks (%d)%s", - inname, unsupported_chunks, strict ? ": IGNORED --strict!" : ""); - } -# endif - - else if (warning_count > 0) - { - fprintf(STDERR, "\n %s: %d libpng warnings found", - inname, warning_count); - - if (strict != 0) - return (1); - } - - pngtest_debug("Opening files for comparison"); - if ((fpin = fopen(inname, "rb")) == NULL) - { - fprintf(STDERR, "Could not find file %s\n", inname); - return (1); - } - - if ((fpout = fopen(outname, "rb")) == NULL) - { - fprintf(STDERR, "Could not find file %s\n", outname); - FCLOSE(fpin); - return (1); - } - -#if defined (PNG_WRITE_SUPPORTED) /* else nothing was written */ &&\ - defined (PNG_WRITE_FILTER_SUPPORTED) - if (interlace_preserved != 0) /* else the files will be changed */ - { - for (;;) - { - static int wrote_question = 0; - png_size_t num_in, num_out; - char inbuf[256], outbuf[256]; - - num_in = fread(inbuf, 1, sizeof inbuf, fpin); - num_out = fread(outbuf, 1, sizeof outbuf, fpout); - - if (num_in != num_out) - { - fprintf(STDERR, "\nFiles %s and %s are of a different size\n", - inname, outname); - - if (wrote_question == 0 && unsupported_chunks == 0) - { - fprintf(STDERR, - " Was %s written with the same maximum IDAT chunk size (%d bytes),", - inname, PNG_ZBUF_SIZE); - fprintf(STDERR, - "\n filtering heuristic (libpng default), compression"); - fprintf(STDERR, - " level (zlib default),\n and zlib version (%s)?\n\n", - ZLIB_VERSION); - wrote_question = 1; - } - - FCLOSE(fpin); - FCLOSE(fpout); - - if (strict != 0 && unsupported_chunks == 0) - return (1); - - else - return (0); - } - - if (num_in == 0) - break; - - if (memcmp(inbuf, outbuf, num_in)) - { - fprintf(STDERR, "\nFiles %s and %s are different\n", inname, - outname); - - if (wrote_question == 0 && unsupported_chunks == 0) - { - fprintf(STDERR, - " Was %s written with the same maximum IDAT chunk size (%d bytes),", - inname, PNG_ZBUF_SIZE); - fprintf(STDERR, - "\n filtering heuristic (libpng default), compression"); - fprintf(STDERR, - " level (zlib default),\n and zlib version (%s)?\n\n", - ZLIB_VERSION); - wrote_question = 1; - } - - FCLOSE(fpin); - FCLOSE(fpout); - - /* NOTE: the unsupported_chunks escape is permitted here because - * unsupported text chunk compression will result in the compression - * mode being changed (to NONE) yet, in the test case, the result - * can be exactly the same size! - */ - if (strict != 0 && unsupported_chunks == 0) - return (1); - - else - return (0); - } - } - } -#endif /* WRITE && WRITE_FILTER */ - - FCLOSE(fpin); - FCLOSE(fpout); - - return (0); -} - -/* Input and output filenames */ -#ifdef RISCOS -static PNG_CONST char *inname = "pngtest/png"; -static PNG_CONST char *outname = "pngout/png"; -#else -static PNG_CONST char *inname = "pngtest.png"; -static PNG_CONST char *outname = "pngout.png"; -#endif - -int -main(int argc, char *argv[]) -{ - int multiple = 0; - int ierror = 0; - - png_structp dummy_ptr; - - fprintf(STDERR, "\n Testing libpng version %s\n", PNG_LIBPNG_VER_STRING); - fprintf(STDERR, " with zlib version %s\n", ZLIB_VERSION); - fprintf(STDERR, "%s", png_get_copyright(NULL)); - /* Show the version of libpng used in building the library */ - fprintf(STDERR, " library (%lu):%s", - (unsigned long)png_access_version_number(), - png_get_header_version(NULL)); - - /* Show the version of libpng used in building the application */ - fprintf(STDERR, " pngtest (%lu):%s", (unsigned long)PNG_LIBPNG_VER, - PNG_HEADER_VERSION_STRING); - - /* Do some consistency checking on the memory allocation settings, I'm - * not sure this matters, but it is nice to know, the first of these - * tests should be impossible because of the way the macros are set - * in pngconf.h - */ -#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) - fprintf(STDERR, " NOTE: Zlib compiled for max 64k, libpng not\n"); -#endif - /* I think the following can happen. */ -#if !defined(MAXSEG_64K) && defined(PNG_MAX_MALLOC_64K) - fprintf(STDERR, " NOTE: libpng compiled for max 64k, zlib not\n"); -#endif - - if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING)) - { - fprintf(STDERR, - "Warning: versions are different between png.h and png.c\n"); - fprintf(STDERR, " png.h version: %s\n", PNG_LIBPNG_VER_STRING); - fprintf(STDERR, " png.c version: %s\n\n", png_libpng_ver); - ++ierror; - } - - if (argc > 1) - { - if (strcmp(argv[1], "-m") == 0) - { - multiple = 1; - status_dots_requested = 0; - } - - else if (strcmp(argv[1], "-mv") == 0 || - strcmp(argv[1], "-vm") == 0 ) - { - multiple = 1; - verbose = 1; - status_dots_requested = 1; - } - - else if (strcmp(argv[1], "-v") == 0) - { - verbose = 1; - status_dots_requested = 1; - inname = argv[2]; - } - - else if (strcmp(argv[1], "--strict") == 0) - { - status_dots_requested = 0; - verbose = 1; - inname = argv[2]; - strict++; - relaxed = 0; - } - - else if (strcmp(argv[1], "--relaxed") == 0) - { - status_dots_requested = 0; - verbose = 1; - inname = argv[2]; - strict = 0; - relaxed++; - } - - else - { - inname = argv[1]; - status_dots_requested = 0; - } - } - - if (multiple == 0 && argc == 3 + verbose) - outname = argv[2 + verbose]; - - if ((multiple == 0 && argc > 3 + verbose) || - (multiple != 0 && argc < 2)) - { - fprintf(STDERR, - "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n", - argv[0], argv[0]); - fprintf(STDERR, - " reads/writes one PNG file (without -m) or multiple files (-m)\n"); - fprintf(STDERR, - " with -m %s is used as a temporary file\n", outname); - exit(1); - } - - if (multiple != 0) - { - int i; -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - int allocation_now = current_allocation; -#endif - for (i=2; i<argc; ++i) - { - int kerror; - fprintf(STDERR, "\n Testing %s:", argv[i]); -#if PNG_DEBUG > 0 - fprintf(STDERR, "\n"); -#endif - kerror = test_one_file(argv[i], outname); - if (kerror == 0) - { -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED - fprintf(STDERR, "\n PASS (%lu zero samples)\n", - (unsigned long)zero_samples); -#else - fprintf(STDERR, " PASS\n"); -#endif -#ifdef PNG_TIME_RFC1123_SUPPORTED - if (tIME_chunk_present != 0) - fprintf(STDERR, " tIME = %s\n", tIME_string); - - tIME_chunk_present = 0; -#endif /* TIME_RFC1123 */ - } - - else - { - fprintf(STDERR, " FAIL\n"); - ierror += kerror; - } -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - if (allocation_now != current_allocation) - fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n", - current_allocation - allocation_now); - - if (current_allocation != 0) - { - memory_infop pinfo = pinformation; - - fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n", - current_allocation); - - while (pinfo != NULL) - { - fprintf(STDERR, " %lu bytes at %p\n", - (unsigned long)pinfo->size, - pinfo->pointer); - pinfo = pinfo->next; - } - } -#endif - } -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - fprintf(STDERR, " Current memory allocation: %10d bytes\n", - current_allocation); - fprintf(STDERR, " Maximum memory allocation: %10d bytes\n", - maximum_allocation); - fprintf(STDERR, " Total memory allocation: %10d bytes\n", - total_allocation); - fprintf(STDERR, " Number of allocations: %10d\n", - num_allocations); -#endif - } - - else - { - int i; - for (i = 0; i<3; ++i) - { - int kerror; -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - int allocation_now = current_allocation; -#endif - if (i == 1) - status_dots_requested = 1; - - else if (verbose == 0) - status_dots_requested = 0; - - if (i == 0 || verbose == 1 || ierror != 0) - { - fprintf(STDERR, "\n Testing %s:", inname); -#if PNG_DEBUG > 0 - fprintf(STDERR, "\n"); -#endif - } - - kerror = test_one_file(inname, outname); - - if (kerror == 0) - { - if (verbose == 1 || i == 2) - { -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED - fprintf(STDERR, "\n PASS (%lu zero samples)\n", - (unsigned long)zero_samples); -#else - fprintf(STDERR, " PASS\n"); -#endif -#ifdef PNG_TIME_RFC1123_SUPPORTED - if (tIME_chunk_present != 0) - fprintf(STDERR, " tIME = %s\n", tIME_string); -#endif /* TIME_RFC1123 */ - } - } - - else - { - if (verbose == 0 && i != 2) - { - fprintf(STDERR, "\n Testing %s:", inname); -#if PNG_DEBUG > 0 - fprintf(STDERR, "\n"); -#endif - } - - fprintf(STDERR, " FAIL\n"); - ierror += kerror; - } -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - if (allocation_now != current_allocation) - fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n", - current_allocation - allocation_now); - - if (current_allocation != 0) - { - memory_infop pinfo = pinformation; - - fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n", - current_allocation); - - while (pinfo != NULL) - { - fprintf(STDERR, " %lu bytes at %p\n", - (unsigned long)pinfo->size, pinfo->pointer); - pinfo = pinfo->next; - } - } -#endif - } -#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG - fprintf(STDERR, " Current memory allocation: %10d bytes\n", - current_allocation); - fprintf(STDERR, " Maximum memory allocation: %10d bytes\n", - maximum_allocation); - fprintf(STDERR, " Total memory allocation: %10d bytes\n", - total_allocation); - fprintf(STDERR, " Number of allocations: %10d\n", - num_allocations); -#endif - } - -#ifdef PNGTEST_TIMING - t_stop = (float)clock(); - t_misc += (t_stop - t_start); - t_start = t_stop; - fprintf(STDERR, " CPU time used = %.3f seconds", - (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC); - fprintf(STDERR, " (decoding %.3f,\n", - t_decode/(float)CLOCKS_PER_SEC); - fprintf(STDERR, " encoding %.3f ,", - t_encode/(float)CLOCKS_PER_SEC); - fprintf(STDERR, " other %.3f seconds)\n\n", - t_misc/(float)CLOCKS_PER_SEC); -#endif - - if (ierror == 0) - fprintf(STDERR, " libpng passes test\n"); - - else - fprintf(STDERR, " libpng FAILS test\n"); - - dummy_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); - fprintf(STDERR, " Default limits:\n"); - fprintf(STDERR, " width_max = %lu\n", - (unsigned long) png_get_user_width_max(dummy_ptr)); - fprintf(STDERR, " height_max = %lu\n", - (unsigned long) png_get_user_height_max(dummy_ptr)); - if (png_get_chunk_cache_max(dummy_ptr) == 0) - fprintf(STDERR, " cache_max = unlimited\n"); - else - fprintf(STDERR, " cache_max = %lu\n", - (unsigned long) png_get_chunk_cache_max(dummy_ptr)); - if (png_get_chunk_malloc_max(dummy_ptr) == 0) - fprintf(STDERR, " malloc_max = unlimited\n"); - else - fprintf(STDERR, " malloc_max = %lu\n", - (unsigned long) png_get_chunk_malloc_max(dummy_ptr)); - png_destroy_read_struct(&dummy_ptr, NULL, NULL); - - return (int)(ierror != 0); -} -#else -int -main(void) -{ - fprintf(STDERR, - " test ignored because libpng was not built with read support\n"); - /* And skip this test */ - return SKIP; -} -#endif - -/* Generate a compiler error if there is an old png.h in the search path. */ -typedef png_libpng_version_1_6_22rc01 Your_png_h_is_not_version_1_6_22rc01; diff --git a/third_party/libpng/pngtrans.c b/third_party/libpng/pngtrans.c deleted file mode 100644 index 7f8cc455d3..0000000000 --- a/third_party/libpng/pngtrans.c +++ /dev/null @@ -1,849 +0,0 @@ - -/* pngtrans.c - transforms the data in a row (used by both readers and writers) - * - * Last changed in libpng 1.6.18 [July 23, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "pngpriv.h" - -#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) - -#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) -/* Turn on BGR-to-RGB mapping */ -void PNGAPI -png_set_bgr(png_structrp png_ptr) -{ - png_debug(1, "in png_set_bgr"); - - if (png_ptr == NULL) - return; - - png_ptr->transformations |= PNG_BGR; -} -#endif - -#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) -/* Turn on 16-bit byte swapping */ -void PNGAPI -png_set_swap(png_structrp png_ptr) -{ - png_debug(1, "in png_set_swap"); - - if (png_ptr == NULL) - return; - - if (png_ptr->bit_depth == 16) - png_ptr->transformations |= PNG_SWAP_BYTES; -} -#endif - -#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) -/* Turn on pixel packing */ -void PNGAPI -png_set_packing(png_structrp png_ptr) -{ - png_debug(1, "in png_set_packing"); - - if (png_ptr == NULL) - return; - - if (png_ptr->bit_depth < 8) - { - png_ptr->transformations |= PNG_PACK; -# ifdef PNG_WRITE_SUPPORTED - png_ptr->usr_bit_depth = 8; -# endif - } -} -#endif - -#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) -/* Turn on packed pixel swapping */ -void PNGAPI -png_set_packswap(png_structrp png_ptr) -{ - png_debug(1, "in png_set_packswap"); - - if (png_ptr == NULL) - return; - - if (png_ptr->bit_depth < 8) - png_ptr->transformations |= PNG_PACKSWAP; -} -#endif - -#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) -void PNGAPI -png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits) -{ - png_debug(1, "in png_set_shift"); - - if (png_ptr == NULL) - return; - - png_ptr->transformations |= PNG_SHIFT; - png_ptr->shift = *true_bits; -} -#endif - -#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ - defined(PNG_WRITE_INTERLACING_SUPPORTED) -int PNGAPI -png_set_interlace_handling(png_structrp png_ptr) -{ - png_debug(1, "in png_set_interlace handling"); - - if (png_ptr != 0 && png_ptr->interlaced != 0) - { - png_ptr->transformations |= PNG_INTERLACE; - return (7); - } - - return (1); -} -#endif - -#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) -/* Add a filler byte on read, or remove a filler or alpha byte on write. - * The filler type has changed in v0.95 to allow future 2-byte fillers - * for 48-bit input data, as well as to avoid problems with some compilers - * that don't like bytes as parameters. - */ -void PNGAPI -png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc) -{ - png_debug(1, "in png_set_filler"); - - if (png_ptr == NULL) - return; - - /* In libpng 1.6 it is possible to determine whether this is a read or write - * operation and therefore to do more checking here for a valid call. - */ - if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) - { -# ifdef PNG_READ_FILLER_SUPPORTED - /* On read png_set_filler is always valid, regardless of the base PNG - * format, because other transformations can give a format where the - * filler code can execute (basically an 8 or 16-bit component RGB or G - * format.) - * - * NOTE: usr_channels is not used by the read code! (This has led to - * confusion in the past.) The filler is only used in the read code. - */ - png_ptr->filler = (png_uint_16)filler; -# else - png_app_error(png_ptr, "png_set_filler not supported on read"); - PNG_UNUSED(filler) /* not used in the write case */ - return; -# endif - } - - else /* write */ - { -# ifdef PNG_WRITE_FILLER_SUPPORTED - /* On write the usr_channels parameter must be set correctly at the - * start to record the number of channels in the app-supplied data. - */ - switch (png_ptr->color_type) - { - case PNG_COLOR_TYPE_RGB: - png_ptr->usr_channels = 4; - break; - - case PNG_COLOR_TYPE_GRAY: - if (png_ptr->bit_depth >= 8) - { - png_ptr->usr_channels = 2; - break; - } - - else - { - /* There simply isn't any code in libpng to strip out bits - * from bytes when the components are less than a byte in - * size! - */ - png_app_error(png_ptr, - "png_set_filler is invalid for low bit depth gray output"); - return; - } - - default: - png_app_error(png_ptr, - "png_set_filler: inappropriate color type"); - return; - } -# else - png_app_error(png_ptr, "png_set_filler not supported on write"); - return; -# endif - } - - /* Here on success - libpng supports the operation, set the transformation - * and the flag to say where the filler channel is. - */ - png_ptr->transformations |= PNG_FILLER; - - if (filler_loc == PNG_FILLER_AFTER) - png_ptr->flags |= PNG_FLAG_FILLER_AFTER; - - else - png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER; -} - -/* Added to libpng-1.2.7 */ -void PNGAPI -png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc) -{ - png_debug(1, "in png_set_add_alpha"); - - if (png_ptr == NULL) - return; - - png_set_filler(png_ptr, filler, filler_loc); - /* The above may fail to do anything. */ - if ((png_ptr->transformations & PNG_FILLER) != 0) - png_ptr->transformations |= PNG_ADD_ALPHA; -} - -#endif - -#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ - defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) -void PNGAPI -png_set_swap_alpha(png_structrp png_ptr) -{ - png_debug(1, "in png_set_swap_alpha"); - - if (png_ptr == NULL) - return; - - png_ptr->transformations |= PNG_SWAP_ALPHA; -} -#endif - -#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ - defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) -void PNGAPI -png_set_invert_alpha(png_structrp png_ptr) -{ - png_debug(1, "in png_set_invert_alpha"); - - if (png_ptr == NULL) - return; - - png_ptr->transformations |= PNG_INVERT_ALPHA; -} -#endif - -#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) -void PNGAPI -png_set_invert_mono(png_structrp png_ptr) -{ - png_debug(1, "in png_set_invert_mono"); - - if (png_ptr == NULL) - return; - - png_ptr->transformations |= PNG_INVERT_MONO; -} - -/* Invert monochrome grayscale data */ -void /* PRIVATE */ -png_do_invert(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_invert"); - - /* This test removed from libpng version 1.0.13 and 1.2.0: - * if (row_info->bit_depth == 1 && - */ - if (row_info->color_type == PNG_COLOR_TYPE_GRAY) - { - png_bytep rp = row; - png_size_t i; - png_size_t istop = row_info->rowbytes; - - for (i = 0; i < istop; i++) - { - *rp = (png_byte)(~(*rp)); - rp++; - } - } - - else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && - row_info->bit_depth == 8) - { - png_bytep rp = row; - png_size_t i; - png_size_t istop = row_info->rowbytes; - - for (i = 0; i < istop; i += 2) - { - *rp = (png_byte)(~(*rp)); - rp += 2; - } - } - -#ifdef PNG_16BIT_SUPPORTED - else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && - row_info->bit_depth == 16) - { - png_bytep rp = row; - png_size_t i; - png_size_t istop = row_info->rowbytes; - - for (i = 0; i < istop; i += 4) - { - *rp = (png_byte)(~(*rp)); - *(rp + 1) = (png_byte)(~(*(rp + 1))); - rp += 4; - } - } -#endif -} -#endif - -#ifdef PNG_16BIT_SUPPORTED -#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) -/* Swaps byte order on 16-bit depth images */ -void /* PRIVATE */ -png_do_swap(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_swap"); - - if (row_info->bit_depth == 16) - { - png_bytep rp = row; - png_uint_32 i; - png_uint_32 istop= row_info->width * row_info->channels; - - for (i = 0; i < istop; i++, rp += 2) - { -#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED - /* Feature added to libpng-1.6.11 for testing purposes, not - * enabled by default. - */ - *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp); -#else - png_byte t = *rp; - *rp = *(rp + 1); - *(rp + 1) = t; -#endif - } - } -} -#endif -#endif - -#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) -static PNG_CONST png_byte onebppswaptable[256] = { - 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, - 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, - 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, - 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, - 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, - 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, - 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, - 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, - 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, - 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, - 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, - 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, - 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, - 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, - 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, - 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, - 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, - 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, - 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, - 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, - 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, - 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, - 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, - 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, - 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, - 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, - 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, - 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, - 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, - 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, - 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, - 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF -}; - -static PNG_CONST png_byte twobppswaptable[256] = { - 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0, - 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0, - 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4, - 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4, - 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8, - 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8, - 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC, - 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC, - 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1, - 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1, - 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5, - 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5, - 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9, - 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9, - 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD, - 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD, - 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2, - 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2, - 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6, - 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6, - 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA, - 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA, - 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE, - 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE, - 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3, - 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3, - 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7, - 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7, - 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB, - 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB, - 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF, - 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF -}; - -static PNG_CONST png_byte fourbppswaptable[256] = { - 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, - 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, - 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71, - 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1, - 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72, - 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2, - 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, - 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3, - 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, - 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4, - 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, - 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5, - 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76, - 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6, - 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77, - 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7, - 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78, - 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8, - 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79, - 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9, - 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, - 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA, - 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, - 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB, - 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C, - 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC, - 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D, - 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD, - 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E, - 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE, - 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F, - 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF -}; - -/* Swaps pixel packing order within bytes */ -void /* PRIVATE */ -png_do_packswap(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_packswap"); - - if (row_info->bit_depth < 8) - { - png_bytep rp; - png_const_bytep end, table; - - end = row + row_info->rowbytes; - - if (row_info->bit_depth == 1) - table = onebppswaptable; - - else if (row_info->bit_depth == 2) - table = twobppswaptable; - - else if (row_info->bit_depth == 4) - table = fourbppswaptable; - - else - return; - - for (rp = row; rp < end; rp++) - *rp = table[*rp]; - } -} -#endif /* PACKSWAP || WRITE_PACKSWAP */ - -#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ - defined(PNG_READ_STRIP_ALPHA_SUPPORTED) -/* Remove a channel - this used to be 'png_do_strip_filler' but it used a - * somewhat weird combination of flags to determine what to do. All the calls - * to png_do_strip_filler are changed in 1.5.2 to call this instead with the - * correct arguments. - * - * The routine isn't general - the channel must be the channel at the start or - * end (not in the middle) of each pixel. - */ -void /* PRIVATE */ -png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start) -{ - png_bytep sp = row; /* source pointer */ - png_bytep dp = row; /* destination pointer */ - png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */ - - /* At the start sp will point to the first byte to copy and dp to where - * it is copied to. ep always points just beyond the end of the row, so - * the loop simply copies (channels-1) channels until sp reaches ep. - * - * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc. - * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc. - */ - - /* GA, GX, XG cases */ - if (row_info->channels == 2) - { - if (row_info->bit_depth == 8) - { - if (at_start != 0) /* Skip initial filler */ - ++sp; - else /* Skip initial channel and, for sp, the filler */ - sp += 2, ++dp; - - /* For a 1 pixel wide image there is nothing to do */ - while (sp < ep) - *dp++ = *sp, sp += 2; - - row_info->pixel_depth = 8; - } - - else if (row_info->bit_depth == 16) - { - if (at_start != 0) /* Skip initial filler */ - sp += 2; - else /* Skip initial channel and, for sp, the filler */ - sp += 4, dp += 2; - - while (sp < ep) - *dp++ = *sp++, *dp++ = *sp, sp += 3; - - row_info->pixel_depth = 16; - } - - else - return; /* bad bit depth */ - - row_info->channels = 1; - - /* Finally fix the color type if it records an alpha channel */ - if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - row_info->color_type = PNG_COLOR_TYPE_GRAY; - } - - /* RGBA, RGBX, XRGB cases */ - else if (row_info->channels == 4) - { - if (row_info->bit_depth == 8) - { - if (at_start != 0) /* Skip initial filler */ - ++sp; - else /* Skip initial channels and, for sp, the filler */ - sp += 4, dp += 3; - - /* Note that the loop adds 3 to dp and 4 to sp each time. */ - while (sp < ep) - *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2; - - row_info->pixel_depth = 24; - } - - else if (row_info->bit_depth == 16) - { - if (at_start != 0) /* Skip initial filler */ - sp += 2; - else /* Skip initial channels and, for sp, the filler */ - sp += 8, dp += 6; - - while (sp < ep) - { - /* Copy 6 bytes, skip 2 */ - *dp++ = *sp++, *dp++ = *sp++; - *dp++ = *sp++, *dp++ = *sp++; - *dp++ = *sp++, *dp++ = *sp, sp += 3; - } - - row_info->pixel_depth = 48; - } - - else - return; /* bad bit depth */ - - row_info->channels = 3; - - /* Finally fix the color type if it records an alpha channel */ - if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - row_info->color_type = PNG_COLOR_TYPE_RGB; - } - - else - return; /* The filler channel has gone already */ - - /* Fix the rowbytes value. */ - row_info->rowbytes = dp-row; -} -#endif - -#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) -/* Swaps red and blue bytes within a pixel */ -void /* PRIVATE */ -png_do_bgr(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_bgr"); - - if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) - { - png_uint_32 row_width = row_info->width; - if (row_info->bit_depth == 8) - { - if (row_info->color_type == PNG_COLOR_TYPE_RGB) - { - png_bytep rp; - png_uint_32 i; - - for (i = 0, rp = row; i < row_width; i++, rp += 3) - { - png_byte save = *rp; - *rp = *(rp + 2); - *(rp + 2) = save; - } - } - - else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - { - png_bytep rp; - png_uint_32 i; - - for (i = 0, rp = row; i < row_width; i++, rp += 4) - { - png_byte save = *rp; - *rp = *(rp + 2); - *(rp + 2) = save; - } - } - } - -#ifdef PNG_16BIT_SUPPORTED - else if (row_info->bit_depth == 16) - { - if (row_info->color_type == PNG_COLOR_TYPE_RGB) - { - png_bytep rp; - png_uint_32 i; - - for (i = 0, rp = row; i < row_width; i++, rp += 6) - { - png_byte save = *rp; - *rp = *(rp + 4); - *(rp + 4) = save; - save = *(rp + 1); - *(rp + 1) = *(rp + 5); - *(rp + 5) = save; - } - } - - else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - { - png_bytep rp; - png_uint_32 i; - - for (i = 0, rp = row; i < row_width; i++, rp += 8) - { - png_byte save = *rp; - *rp = *(rp + 4); - *(rp + 4) = save; - save = *(rp + 1); - *(rp + 1) = *(rp + 5); - *(rp + 5) = save; - } - } - } -#endif - } -} -#endif /* READ_BGR || WRITE_BGR */ - -#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ - defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) -/* Added at libpng-1.5.10 */ -void /* PRIVATE */ -png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info) -{ - if (png_ptr->num_palette < (1 << row_info->bit_depth) && - png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */ - { - /* Calculations moved outside switch in an attempt to stop different - * compiler warnings. 'padding' is in *bits* within the last byte, it is - * an 'int' because pixel_depth becomes an 'int' in the expression below, - * and this calculation is used because it avoids warnings that other - * forms produced on either GCC or MSVC. - */ - int padding = (-row_info->pixel_depth * row_info->width) & 7; - png_bytep rp = png_ptr->row_buf + row_info->rowbytes; - - switch (row_info->bit_depth) - { - case 1: - { - /* in this case, all bytes must be 0 so we don't need - * to unpack the pixels except for the rightmost one. - */ - for (; rp > png_ptr->row_buf; rp--) - { - if ((*rp >> padding) != 0) - png_ptr->num_palette_max = 1; - padding = 0; - } - - break; - } - - case 2: - { - for (; rp > png_ptr->row_buf; rp--) - { - int i = ((*rp >> padding) & 0x03); - - if (i > png_ptr->num_palette_max) - png_ptr->num_palette_max = i; - - i = (((*rp >> padding) >> 2) & 0x03); - - if (i > png_ptr->num_palette_max) - png_ptr->num_palette_max = i; - - i = (((*rp >> padding) >> 4) & 0x03); - - if (i > png_ptr->num_palette_max) - png_ptr->num_palette_max = i; - - i = (((*rp >> padding) >> 6) & 0x03); - - if (i > png_ptr->num_palette_max) - png_ptr->num_palette_max = i; - - padding = 0; - } - - break; - } - - case 4: - { - for (; rp > png_ptr->row_buf; rp--) - { - int i = ((*rp >> padding) & 0x0f); - - if (i > png_ptr->num_palette_max) - png_ptr->num_palette_max = i; - - i = (((*rp >> padding) >> 4) & 0x0f); - - if (i > png_ptr->num_palette_max) - png_ptr->num_palette_max = i; - - padding = 0; - } - - break; - } - - case 8: - { - for (; rp > png_ptr->row_buf; rp--) - { - if (*rp > png_ptr->num_palette_max) - png_ptr->num_palette_max = (int) *rp; - } - - break; - } - - default: - break; - } - } -} -#endif /* CHECK_FOR_INVALID_INDEX */ - -#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ - defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) -#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED -void PNGAPI -png_set_user_transform_info(png_structrp png_ptr, png_voidp - user_transform_ptr, int user_transform_depth, int user_transform_channels) -{ - png_debug(1, "in png_set_user_transform_info"); - - if (png_ptr == NULL) - return; - -#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED - if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && - (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0) - { - png_app_error(png_ptr, - "info change after png_start_read_image or png_read_update_info"); - return; - } -#endif - - png_ptr->user_transform_ptr = user_transform_ptr; - png_ptr->user_transform_depth = (png_byte)user_transform_depth; - png_ptr->user_transform_channels = (png_byte)user_transform_channels; -} -#endif - -/* This function returns a pointer to the user_transform_ptr associated with - * the user transform functions. The application should free any memory - * associated with this pointer before png_write_destroy and png_read_destroy - * are called. - */ -#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED -png_voidp PNGAPI -png_get_user_transform_ptr(png_const_structrp png_ptr) -{ - if (png_ptr == NULL) - return (NULL); - - return png_ptr->user_transform_ptr; -} -#endif - -#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED -png_uint_32 PNGAPI -png_get_current_row_number(png_const_structrp png_ptr) -{ - /* See the comments in png.h - this is the sub-image row when reading an - * interlaced image. - */ - if (png_ptr != NULL) - return png_ptr->row_number; - - return PNG_UINT_32_MAX; /* help the app not to fail silently */ -} - -png_byte PNGAPI -png_get_current_pass_number(png_const_structrp png_ptr) -{ - if (png_ptr != NULL) - return png_ptr->pass; - return 8; /* invalid */ -} -#endif /* USER_TRANSFORM_INFO */ -#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */ -#endif /* READ || WRITE */ diff --git a/third_party/libpng/pngwio.c b/third_party/libpng/pngwio.c deleted file mode 100644 index 586c03b721..0000000000 --- a/third_party/libpng/pngwio.c +++ /dev/null @@ -1,168 +0,0 @@ - -/* pngwio.c - functions for data output - * - * Last changed in libpng 1.6.15 [November 20, 2014] - * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * This file provides a location for all output. Users who need - * special handling are expected to write functions that have the same - * arguments as these and perform similar functions, but that possibly - * use different output methods. Note that you shouldn't change these - * functions, but rather write replacement functions and then change - * them at run time with png_set_write_fn(...). - */ - -#include "pngpriv.h" - -#ifdef PNG_WRITE_SUPPORTED - -/* Write the data to whatever output you are using. The default routine - * writes to a file pointer. Note that this routine sometimes gets called - * with very small lengths, so you should implement some kind of simple - * buffering if you are using unbuffered writes. This should never be asked - * to write more than 64K on a 16-bit machine. - */ - -void /* PRIVATE */ -png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length) -{ - /* NOTE: write_data_fn must not change the buffer! */ - if (png_ptr->write_data_fn != NULL ) - (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data), - length); - - else - png_error(png_ptr, "Call to NULL write function"); -} - -#ifdef PNG_STDIO_SUPPORTED -/* This is the function that does the actual writing of data. If you are - * not writing to a standard C stream, you should create a replacement - * write_data function and use it at run time with png_set_write_fn(), rather - * than changing the library. - */ -void PNGCBAPI -png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) -{ - png_size_t check; - - if (png_ptr == NULL) - return; - - check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr)); - - if (check != length) - png_error(png_ptr, "Write Error"); -} -#endif - -/* This function is called to output any data pending writing (normally - * to disk). After png_flush is called, there should be no data pending - * writing in any buffers. - */ -#ifdef PNG_WRITE_FLUSH_SUPPORTED -void /* PRIVATE */ -png_flush(png_structrp png_ptr) -{ - if (png_ptr->output_flush_fn != NULL) - (*(png_ptr->output_flush_fn))(png_ptr); -} - -# ifdef PNG_STDIO_SUPPORTED -void PNGCBAPI -png_default_flush(png_structp png_ptr) -{ - png_FILE_p io_ptr; - - if (png_ptr == NULL) - return; - - io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr)); - fflush(io_ptr); -} -# endif -#endif - -/* This function allows the application to supply new output functions for - * libpng if standard C streams aren't being used. - * - * This function takes as its arguments: - * png_ptr - pointer to a png output data structure - * io_ptr - pointer to user supplied structure containing info about - * the output functions. May be NULL. - * write_data_fn - pointer to a new output function that takes as its - * arguments a pointer to a png_struct, a pointer to - * data to be written, and a 32-bit unsigned int that is - * the number of bytes to be written. The new write - * function should call png_error(png_ptr, "Error msg") - * to exit and output any fatal error messages. May be - * NULL, in which case libpng's default function will - * be used. - * flush_data_fn - pointer to a new flush function that takes as its - * arguments a pointer to a png_struct. After a call to - * the flush function, there should be no data in any buffers - * or pending transmission. If the output method doesn't do - * any buffering of output, a function prototype must still be - * supplied although it doesn't have to do anything. If - * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile - * time, output_flush_fn will be ignored, although it must be - * supplied for compatibility. May be NULL, in which case - * libpng's default function will be used, if - * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not - * a good idea if io_ptr does not point to a standard - * *FILE structure. - */ -void PNGAPI -png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr, - png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) -{ - if (png_ptr == NULL) - return; - - png_ptr->io_ptr = io_ptr; - -#ifdef PNG_STDIO_SUPPORTED - if (write_data_fn != NULL) - png_ptr->write_data_fn = write_data_fn; - - else - png_ptr->write_data_fn = png_default_write_data; -#else - png_ptr->write_data_fn = write_data_fn; -#endif - -#ifdef PNG_WRITE_FLUSH_SUPPORTED -# ifdef PNG_STDIO_SUPPORTED - - if (output_flush_fn != NULL) - png_ptr->output_flush_fn = output_flush_fn; - - else - png_ptr->output_flush_fn = png_default_flush; - -# else - png_ptr->output_flush_fn = output_flush_fn; -# endif -#else - PNG_UNUSED(output_flush_fn) -#endif /* WRITE_FLUSH */ - -#ifdef PNG_READ_SUPPORTED - /* It is an error to read while writing a png file */ - if (png_ptr->read_data_fn != NULL) - { - png_ptr->read_data_fn = NULL; - - png_warning(png_ptr, - "Can't set both read_data_fn and write_data_fn in the" - " same structure"); - } -#endif -} -#endif /* WRITE */ diff --git a/third_party/libpng/pngwrite.c b/third_party/libpng/pngwrite.c deleted file mode 100644 index 181a899438..0000000000 --- a/third_party/libpng/pngwrite.c +++ /dev/null @@ -1,2383 +0,0 @@ - -/* pngwrite.c - general routines to write a PNG file - * - * Last changed in libpng 1.6.19 [November 12, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "pngpriv.h" -#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED -# include <errno.h> -#endif /* SIMPLIFIED_WRITE_STDIO */ - -#ifdef PNG_WRITE_SUPPORTED - -#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED -/* Write out all the unknown chunks for the current given location */ -static void -write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr, - unsigned int where) -{ - if (info_ptr->unknown_chunks_num != 0) - { - png_const_unknown_chunkp up; - - png_debug(5, "writing extra chunks"); - - for (up = info_ptr->unknown_chunks; - up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num; - ++up) - if ((up->location & where) != 0) - { - /* If per-chunk unknown chunk handling is enabled use it, otherwise - * just write the chunks the application has set. - */ -#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED - int keep = png_handle_as_unknown(png_ptr, up->name); - - /* NOTE: this code is radically different from the read side in the - * matter of handling an ancillary unknown chunk. In the read side - * the default behavior is to discard it, in the code below the default - * behavior is to write it. Critical chunks are, however, only - * written if explicitly listed or if the default is set to write all - * unknown chunks. - * - * The default handling is also slightly weird - it is not possible to - * stop the writing of all unsafe-to-copy chunks! - * - * TODO: REVIEW: this would seem to be a bug. - */ - if (keep != PNG_HANDLE_CHUNK_NEVER && - ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ || - keep == PNG_HANDLE_CHUNK_ALWAYS || - (keep == PNG_HANDLE_CHUNK_AS_DEFAULT && - png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS))) -#endif - { - /* TODO: review, what is wrong with a zero length unknown chunk? */ - if (up->size == 0) - png_warning(png_ptr, "Writing zero-length unknown chunk"); - - png_write_chunk(png_ptr, up->name, up->data, up->size); - } - } - } -} -#endif /* WRITE_UNKNOWN_CHUNKS */ - -/* Writes all the PNG information. This is the suggested way to use the - * library. If you have a new chunk to add, make a function to write it, - * and put it in the correct location here. If you want the chunk written - * after the image data, put it in png_write_end(). I strongly encourage - * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing - * the chunk, as that will keep the code from breaking if you want to just - * write a plain PNG file. If you have long comments, I suggest writing - * them in png_write_end(), and compressing them. - */ -void PNGAPI -png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr) -{ - png_debug(1, "in png_write_info_before_PLTE"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) - { - /* Write PNG signature */ - png_write_sig(png_ptr); - -#ifdef PNG_MNG_FEATURES_SUPPORTED - if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \ - png_ptr->mng_features_permitted != 0) - { - png_warning(png_ptr, - "MNG features are not allowed in a PNG datastream"); - png_ptr->mng_features_permitted = 0; - } -#endif - - /* Write IHDR information. */ - png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height, - info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type, - info_ptr->filter_type, -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - info_ptr->interlace_type -#else - 0 -#endif - ); - - /* The rest of these check to see if the valid field has the appropriate - * flag set, and if it does, writes the chunk. - * - * 1.6.0: COLORSPACE support controls the writing of these chunks too, and - * the chunks will be written if the WRITE routine is there and - * information * is available in the COLORSPACE. (See - * png_colorspace_sync_info in png.c for where the valid flags get set.) - * - * Under certain circumstances the colorspace can be invalidated without - * syncing the info_struct 'valid' flags; this happens if libpng detects - * an error and calls png_error while the color space is being set, yet - * the application continues writing the PNG. So check the 'invalid' - * flag here too. - */ -#ifdef PNG_GAMMA_SUPPORTED -# ifdef PNG_WRITE_gAMA_SUPPORTED - if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && - (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 && - (info_ptr->valid & PNG_INFO_gAMA) != 0) - png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma); -# endif -#endif - -#ifdef PNG_COLORSPACE_SUPPORTED - /* Write only one of sRGB or an ICC profile. If a profile was supplied - * and it matches one of the known sRGB ones issue a warning. - */ -# ifdef PNG_WRITE_iCCP_SUPPORTED - if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && - (info_ptr->valid & PNG_INFO_iCCP) != 0) - { -# ifdef PNG_WRITE_sRGB_SUPPORTED - if ((info_ptr->valid & PNG_INFO_sRGB) != 0) - png_app_warning(png_ptr, - "profile matches sRGB but writing iCCP instead"); -# endif - - png_write_iCCP(png_ptr, info_ptr->iccp_name, - info_ptr->iccp_profile); - } -# ifdef PNG_WRITE_sRGB_SUPPORTED - else -# endif -# endif - -# ifdef PNG_WRITE_sRGB_SUPPORTED - if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && - (info_ptr->valid & PNG_INFO_sRGB) != 0) - png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent); -# endif /* WRITE_sRGB */ -#endif /* COLORSPACE */ - -#ifdef PNG_WRITE_sBIT_SUPPORTED - if ((info_ptr->valid & PNG_INFO_sBIT) != 0) - png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); -#endif - -#ifdef PNG_COLORSPACE_SUPPORTED -# ifdef PNG_WRITE_cHRM_SUPPORTED - if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && - (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 && - (info_ptr->valid & PNG_INFO_cHRM) != 0) - png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy); -# endif -#endif - -#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR); -#endif - - png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE; - } -} - -void PNGAPI -png_write_info(png_structrp png_ptr, png_const_inforp info_ptr) -{ -#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) - int i; -#endif - - png_debug(1, "in png_write_info"); - - if (png_ptr == NULL || info_ptr == NULL) - return; - - png_write_info_before_PLTE(png_ptr, info_ptr); - - if ((info_ptr->valid & PNG_INFO_PLTE) != 0) - png_write_PLTE(png_ptr, info_ptr->palette, - (png_uint_32)info_ptr->num_palette); - - else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - png_error(png_ptr, "Valid palette required for paletted images"); - -#ifdef PNG_WRITE_tRNS_SUPPORTED - if ((info_ptr->valid & PNG_INFO_tRNS) !=0) - { -#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED - /* Invert the alpha channel (in tRNS) */ - if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 && - info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - int j, jend; - - jend = info_ptr->num_trans; - if (jend > PNG_MAX_PALETTE_LENGTH) - jend = PNG_MAX_PALETTE_LENGTH; - - for (j = 0; j<jend; ++j) - info_ptr->trans_alpha[j] = - (png_byte)(255 - info_ptr->trans_alpha[j]); - } -#endif - png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color), - info_ptr->num_trans, info_ptr->color_type); - } -#endif -#ifdef PNG_WRITE_bKGD_SUPPORTED - if ((info_ptr->valid & PNG_INFO_bKGD) != 0) - png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type); -#endif - -#ifdef PNG_WRITE_hIST_SUPPORTED - if ((info_ptr->valid & PNG_INFO_hIST) != 0) - png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette); -#endif - -#ifdef PNG_WRITE_oFFs_SUPPORTED - if ((info_ptr->valid & PNG_INFO_oFFs) != 0) - png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset, - info_ptr->offset_unit_type); -#endif - -#ifdef PNG_WRITE_pCAL_SUPPORTED - if ((info_ptr->valid & PNG_INFO_pCAL) != 0) - png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0, - info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams, - info_ptr->pcal_units, info_ptr->pcal_params); -#endif - -#ifdef PNG_WRITE_sCAL_SUPPORTED - if ((info_ptr->valid & PNG_INFO_sCAL) != 0) - png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit, - info_ptr->scal_s_width, info_ptr->scal_s_height); -#endif /* sCAL */ - -#ifdef PNG_WRITE_pHYs_SUPPORTED - if ((info_ptr->valid & PNG_INFO_pHYs) != 0) - png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit, - info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type); -#endif /* pHYs */ - -#ifdef PNG_WRITE_tIME_SUPPORTED - if ((info_ptr->valid & PNG_INFO_tIME) != 0) - { - png_write_tIME(png_ptr, &(info_ptr->mod_time)); - png_ptr->mode |= PNG_WROTE_tIME; - } -#endif /* tIME */ - -#ifdef PNG_WRITE_sPLT_SUPPORTED - if ((info_ptr->valid & PNG_INFO_sPLT) != 0) - for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) - png_write_sPLT(png_ptr, info_ptr->splt_palettes + i); -#endif /* sPLT */ - -#ifdef PNG_WRITE_TEXT_SUPPORTED - /* Check to see if we need to write text chunks */ - for (i = 0; i < info_ptr->num_text; i++) - { - png_debug2(2, "Writing header text chunk %d, type %d", i, - info_ptr->text[i].compression); - /* An internationalized chunk? */ - if (info_ptr->text[i].compression > 0) - { -#ifdef PNG_WRITE_iTXt_SUPPORTED - /* Write international chunk */ - png_write_iTXt(png_ptr, - info_ptr->text[i].compression, - info_ptr->text[i].key, - info_ptr->text[i].lang, - info_ptr->text[i].lang_key, - info_ptr->text[i].text); - /* Mark this chunk as written */ - if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; - else - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; -#else - png_warning(png_ptr, "Unable to write international text"); -#endif - } - - /* If we want a compressed text chunk */ - else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt) - { -#ifdef PNG_WRITE_zTXt_SUPPORTED - /* Write compressed chunk */ - png_write_zTXt(png_ptr, info_ptr->text[i].key, - info_ptr->text[i].text, info_ptr->text[i].compression); - /* Mark this chunk as written */ - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; -#else - png_warning(png_ptr, "Unable to write compressed text"); -#endif - } - - else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) - { -#ifdef PNG_WRITE_tEXt_SUPPORTED - /* Write uncompressed chunk */ - png_write_tEXt(png_ptr, info_ptr->text[i].key, - info_ptr->text[i].text, - 0); - /* Mark this chunk as written */ - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; -#else - /* Can't get here */ - png_warning(png_ptr, "Unable to write uncompressed text"); -#endif - } - } -#endif /* tEXt */ - -#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE); -#endif -} - -/* Writes the end of the PNG file. If you don't want to write comments or - * time information, you can pass NULL for info. If you already wrote these - * in png_write_info(), do not write them again here. If you have long - * comments, I suggest writing them here, and compressing them. - */ -void PNGAPI -png_write_end(png_structrp png_ptr, png_inforp info_ptr) -{ - png_debug(1, "in png_write_end"); - - if (png_ptr == NULL) - return; - - if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) - png_error(png_ptr, "No IDATs written into file"); - -#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED - if (png_ptr->num_palette_max > png_ptr->num_palette) - png_benign_error(png_ptr, "Wrote palette index exceeding num_palette"); -#endif - - /* See if user wants us to write information chunks */ - if (info_ptr != NULL) - { -#ifdef PNG_WRITE_TEXT_SUPPORTED - int i; /* local index variable */ -#endif -#ifdef PNG_WRITE_tIME_SUPPORTED - /* Check to see if user has supplied a time chunk */ - if ((info_ptr->valid & PNG_INFO_tIME) != 0 && - (png_ptr->mode & PNG_WROTE_tIME) == 0) - png_write_tIME(png_ptr, &(info_ptr->mod_time)); - -#endif -#ifdef PNG_WRITE_TEXT_SUPPORTED - /* Loop through comment chunks */ - for (i = 0; i < info_ptr->num_text; i++) - { - png_debug2(2, "Writing trailer text chunk %d, type %d", i, - info_ptr->text[i].compression); - /* An internationalized chunk? */ - if (info_ptr->text[i].compression > 0) - { -#ifdef PNG_WRITE_iTXt_SUPPORTED - /* Write international chunk */ - png_write_iTXt(png_ptr, - info_ptr->text[i].compression, - info_ptr->text[i].key, - info_ptr->text[i].lang, - info_ptr->text[i].lang_key, - info_ptr->text[i].text); - /* Mark this chunk as written */ - if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; - else - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; -#else - png_warning(png_ptr, "Unable to write international text"); -#endif - } - - else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt) - { -#ifdef PNG_WRITE_zTXt_SUPPORTED - /* Write compressed chunk */ - png_write_zTXt(png_ptr, info_ptr->text[i].key, - info_ptr->text[i].text, info_ptr->text[i].compression); - /* Mark this chunk as written */ - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; -#else - png_warning(png_ptr, "Unable to write compressed text"); -#endif - } - - else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) - { -#ifdef PNG_WRITE_tEXt_SUPPORTED - /* Write uncompressed chunk */ - png_write_tEXt(png_ptr, info_ptr->text[i].key, - info_ptr->text[i].text, 0); - /* Mark this chunk as written */ - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; -#else - png_warning(png_ptr, "Unable to write uncompressed text"); -#endif - } - } -#endif -#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT); -#endif - } - - png_ptr->mode |= PNG_AFTER_IDAT; - - /* Write end of PNG file */ - png_write_IEND(png_ptr); - - /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03, - * and restored again in libpng-1.2.30, may cause some applications that - * do not set png_ptr->output_flush_fn to crash. If your application - * experiences a problem, please try building libpng with - * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to - * png-mng-implement at lists.sf.net . - */ -#ifdef PNG_WRITE_FLUSH_SUPPORTED -# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED - png_flush(png_ptr); -# endif -#endif -} - -#ifdef PNG_CONVERT_tIME_SUPPORTED -void PNGAPI -png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime) -{ - png_debug(1, "in png_convert_from_struct_tm"); - - ptime->year = (png_uint_16)(1900 + ttime->tm_year); - ptime->month = (png_byte)(ttime->tm_mon + 1); - ptime->day = (png_byte)ttime->tm_mday; - ptime->hour = (png_byte)ttime->tm_hour; - ptime->minute = (png_byte)ttime->tm_min; - ptime->second = (png_byte)ttime->tm_sec; -} - -void PNGAPI -png_convert_from_time_t(png_timep ptime, time_t ttime) -{ - struct tm *tbuf; - - png_debug(1, "in png_convert_from_time_t"); - - tbuf = gmtime(&ttime); - png_convert_from_struct_tm(ptime, tbuf); -} -#endif - -/* Initialize png_ptr structure, and allocate any memory needed */ -PNG_FUNCTION(png_structp,PNGAPI -png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr, - png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) -{ -#ifndef PNG_USER_MEM_SUPPORTED - png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, - error_fn, warn_fn, NULL, NULL, NULL); -#else - return png_create_write_struct_2(user_png_ver, error_ptr, error_fn, - warn_fn, NULL, NULL, NULL); -} - -/* Alternate initialize png_ptr structure, and allocate any memory needed */ -PNG_FUNCTION(png_structp,PNGAPI -png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, - png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, - png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) -{ - png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, - error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); -#endif /* USER_MEM */ - if (png_ptr != NULL) - { - /* Set the zlib control values to defaults; they can be overridden by the - * application after the struct has been created. - */ - png_ptr->zbuffer_size = PNG_ZBUF_SIZE; - - /* The 'zlib_strategy' setting is irrelevant because png_default_claim in - * pngwutil.c defaults it according to whether or not filters will be - * used, and ignores this setting. - */ - png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY; - png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION; - png_ptr->zlib_mem_level = 8; - png_ptr->zlib_window_bits = 15; - png_ptr->zlib_method = 8; - -#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED - png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY; - png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION; - png_ptr->zlib_text_mem_level = 8; - png_ptr->zlib_text_window_bits = 15; - png_ptr->zlib_text_method = 8; -#endif /* WRITE_COMPRESSED_TEXT */ - - /* This is a highly dubious configuration option; by default it is off, - * but it may be appropriate for private builds that are testing - * extensions not conformant to the current specification, or of - * applications that must not fail to write at all costs! - */ -#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED - /* In stable builds only warn if an application error can be completely - * handled. - */ - png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; -#endif - - /* App warnings are warnings in release (or release candidate) builds but - * are errors during development. - */ -#if PNG_RELEASE_BUILD - png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; -#endif - - /* TODO: delay this, it can be done in png_init_io() (if the app doesn't - * do it itself) avoiding setting the default function if it is not - * required. - */ - png_set_write_fn(png_ptr, NULL, NULL, NULL); - } - - return png_ptr; -} - - -/* Write a few rows of image data. If the image is interlaced, - * either you will have to write the 7 sub images, or, if you - * have called png_set_interlace_handling(), you will have to - * "write" the image seven times. - */ -void PNGAPI -png_write_rows(png_structrp png_ptr, png_bytepp row, - png_uint_32 num_rows) -{ - png_uint_32 i; /* row counter */ - png_bytepp rp; /* row pointer */ - - png_debug(1, "in png_write_rows"); - - if (png_ptr == NULL) - return; - - /* Loop through the rows */ - for (i = 0, rp = row; i < num_rows; i++, rp++) - { - png_write_row(png_ptr, *rp); - } -} - -/* Write the image. You only need to call this function once, even - * if you are writing an interlaced image. - */ -void PNGAPI -png_write_image(png_structrp png_ptr, png_bytepp image) -{ - png_uint_32 i; /* row index */ - int pass, num_pass; /* pass variables */ - png_bytepp rp; /* points to current row */ - - if (png_ptr == NULL) - return; - - png_debug(1, "in png_write_image"); - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* Initialize interlace handling. If image is not interlaced, - * this will set pass to 1 - */ - num_pass = png_set_interlace_handling(png_ptr); -#else - num_pass = 1; -#endif - /* Loop through passes */ - for (pass = 0; pass < num_pass; pass++) - { - /* Loop through image */ - for (i = 0, rp = image; i < png_ptr->height; i++, rp++) - { - png_write_row(png_ptr, *rp); - } - } -} - -#ifdef PNG_MNG_FEATURES_SUPPORTED -/* Performs intrapixel differencing */ -static void -png_do_write_intrapixel(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_write_intrapixel"); - - if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) - { - int bytes_per_pixel; - png_uint_32 row_width = row_info->width; - if (row_info->bit_depth == 8) - { - png_bytep rp; - png_uint_32 i; - - if (row_info->color_type == PNG_COLOR_TYPE_RGB) - bytes_per_pixel = 3; - - else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - bytes_per_pixel = 4; - - else - return; - - for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) - { - *(rp) = (png_byte)(*rp - *(rp + 1)); - *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1)); - } - } - -#ifdef PNG_WRITE_16BIT_SUPPORTED - else if (row_info->bit_depth == 16) - { - png_bytep rp; - png_uint_32 i; - - if (row_info->color_type == PNG_COLOR_TYPE_RGB) - bytes_per_pixel = 6; - - else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - bytes_per_pixel = 8; - - else - return; - - for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) - { - png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); - png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); - png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); - png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); - png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); - *(rp ) = (png_byte)(red >> 8); - *(rp + 1) = (png_byte)red; - *(rp + 4) = (png_byte)(blue >> 8); - *(rp + 5) = (png_byte)blue; - } - } -#endif /* WRITE_16BIT */ - } -} -#endif /* MNG_FEATURES */ - -/* Called by user to write a row of image data */ -void PNGAPI -png_write_row(png_structrp png_ptr, png_const_bytep row) -{ - /* 1.5.6: moved from png_struct to be a local structure: */ - png_row_info row_info; - - if (png_ptr == NULL) - return; - - png_debug2(1, "in png_write_row (row %u, pass %d)", - png_ptr->row_number, png_ptr->pass); - - /* Initialize transformations and other stuff if first time */ - if (png_ptr->row_number == 0 && png_ptr->pass == 0) - { - /* Make sure we wrote the header info */ - if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) - png_error(png_ptr, - "png_write_info was never called before png_write_row"); - - /* Check for transforms that have been set but were defined out */ -#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED) - if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) - png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined"); -#endif - -#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED) - if ((png_ptr->transformations & PNG_FILLER) != 0) - png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined"); -#endif -#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ - defined(PNG_READ_PACKSWAP_SUPPORTED) - if ((png_ptr->transformations & PNG_PACKSWAP) != 0) - png_warning(png_ptr, - "PNG_WRITE_PACKSWAP_SUPPORTED is not defined"); -#endif - -#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED) - if ((png_ptr->transformations & PNG_PACK) != 0) - png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined"); -#endif - -#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED) - if ((png_ptr->transformations & PNG_SHIFT) != 0) - png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined"); -#endif - -#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED) - if ((png_ptr->transformations & PNG_BGR) != 0) - png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined"); -#endif - -#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED) - if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) - png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined"); -#endif - - png_write_start_row(png_ptr); - } - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* If interlaced and not interested in row, return */ - if (png_ptr->interlaced != 0 && - (png_ptr->transformations & PNG_INTERLACE) != 0) - { - switch (png_ptr->pass) - { - case 0: - if ((png_ptr->row_number & 0x07) != 0) - { - png_write_finish_row(png_ptr); - return; - } - break; - - case 1: - if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5) - { - png_write_finish_row(png_ptr); - return; - } - break; - - case 2: - if ((png_ptr->row_number & 0x07) != 4) - { - png_write_finish_row(png_ptr); - return; - } - break; - - case 3: - if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3) - { - png_write_finish_row(png_ptr); - return; - } - break; - - case 4: - if ((png_ptr->row_number & 0x03) != 2) - { - png_write_finish_row(png_ptr); - return; - } - break; - - case 5: - if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2) - { - png_write_finish_row(png_ptr); - return; - } - break; - - case 6: - if ((png_ptr->row_number & 0x01) == 0) - { - png_write_finish_row(png_ptr); - return; - } - break; - - default: /* error: ignore it */ - break; - } - } -#endif - - /* Set up row info for transformations */ - row_info.color_type = png_ptr->color_type; - row_info.width = png_ptr->usr_width; - row_info.channels = png_ptr->usr_channels; - row_info.bit_depth = png_ptr->usr_bit_depth; - row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels); - row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); - - png_debug1(3, "row_info->color_type = %d", row_info.color_type); - png_debug1(3, "row_info->width = %u", row_info.width); - png_debug1(3, "row_info->channels = %d", row_info.channels); - png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth); - png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth); - png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes); - - /* Copy user's row into buffer, leaving room for filter byte. */ - memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes); - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* Handle interlacing */ - if (png_ptr->interlaced && png_ptr->pass < 6 && - (png_ptr->transformations & PNG_INTERLACE) != 0) - { - png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass); - /* This should always get caught above, but still ... */ - if (row_info.width == 0) - { - png_write_finish_row(png_ptr); - return; - } - } -#endif - -#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED - /* Handle other transformations */ - if (png_ptr->transformations != 0) - png_do_write_transformations(png_ptr, &row_info); -#endif - - /* At this point the row_info pixel depth must match the 'transformed' depth, - * which is also the output depth. - */ - if (row_info.pixel_depth != png_ptr->pixel_depth || - row_info.pixel_depth != png_ptr->transformed_pixel_depth) - png_error(png_ptr, "internal write transform logic error"); - -#ifdef PNG_MNG_FEATURES_SUPPORTED - /* Write filter_method 64 (intrapixel differencing) only if - * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and - * 2. Libpng did not write a PNG signature (this filter_method is only - * used in PNG datastreams that are embedded in MNG datastreams) and - * 3. The application called png_permit_mng_features with a mask that - * included PNG_FLAG_MNG_FILTER_64 and - * 4. The filter_method is 64 and - * 5. The color_type is RGB or RGBA - */ - if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && - (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) - { - /* Intrapixel differencing */ - png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1); - } -#endif - -/* Added at libpng-1.5.10 */ -#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED - /* Check for out-of-range palette index */ - if (row_info.color_type == PNG_COLOR_TYPE_PALETTE && - png_ptr->num_palette_max >= 0) - png_do_check_palette_indexes(png_ptr, &row_info); -#endif - - /* Find a filter if necessary, filter the row and write it out. */ - png_write_find_filter(png_ptr, &row_info); - - if (png_ptr->write_row_fn != NULL) - (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); -} - -#ifdef PNG_WRITE_FLUSH_SUPPORTED -/* Set the automatic flush interval or 0 to turn flushing off */ -void PNGAPI -png_set_flush(png_structrp png_ptr, int nrows) -{ - png_debug(1, "in png_set_flush"); - - if (png_ptr == NULL) - return; - - png_ptr->flush_dist = (nrows < 0 ? 0 : nrows); -} - -/* Flush the current output buffers now */ -void PNGAPI -png_write_flush(png_structrp png_ptr) -{ - png_debug(1, "in png_write_flush"); - - if (png_ptr == NULL) - return; - - /* We have already written out all of the data */ - if (png_ptr->row_number >= png_ptr->num_rows) - return; - - png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH); - png_ptr->flush_rows = 0; - png_flush(png_ptr); -} -#endif /* WRITE_FLUSH */ - -/* Free any memory used in png_ptr struct without freeing the struct itself. */ -static void -png_write_destroy(png_structrp png_ptr) -{ - png_debug(1, "in png_write_destroy"); - - /* Free any memory zlib uses */ - if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) - deflateEnd(&png_ptr->zstream); - - /* Free our memory. png_free checks NULL for us. */ - png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); - png_free(png_ptr, png_ptr->row_buf); - png_ptr->row_buf = NULL; -#ifdef PNG_WRITE_FILTER_SUPPORTED - png_free(png_ptr, png_ptr->prev_row); - png_free(png_ptr, png_ptr->try_row); - png_free(png_ptr, png_ptr->tst_row); - png_ptr->prev_row = NULL; - png_ptr->try_row = NULL; - png_ptr->tst_row = NULL; -#endif - -#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED - png_free(png_ptr, png_ptr->chunk_list); - png_ptr->chunk_list = NULL; -#endif - - /* The error handling and memory handling information is left intact at this - * point: the jmp_buf may still have to be freed. See png_destroy_png_struct - * for how this happens. - */ -} - -/* Free all memory used by the write. - * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for - * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free - * the passed in info_structs but it would quietly fail to free any of the data - * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it - * has no png_ptr.) - */ -void PNGAPI -png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) -{ - png_debug(1, "in png_destroy_write_struct"); - - if (png_ptr_ptr != NULL) - { - png_structrp png_ptr = *png_ptr_ptr; - - if (png_ptr != NULL) /* added in libpng 1.6.0 */ - { - png_destroy_info_struct(png_ptr, info_ptr_ptr); - - *png_ptr_ptr = NULL; - png_write_destroy(png_ptr); - png_destroy_png_struct(png_ptr); - } - } -} - -/* Allow the application to select one or more row filters to use. */ -void PNGAPI -png_set_filter(png_structrp png_ptr, int method, int filters) -{ - png_debug(1, "in png_set_filter"); - - if (png_ptr == NULL) - return; - -#ifdef PNG_MNG_FEATURES_SUPPORTED - if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && - (method == PNG_INTRAPIXEL_DIFFERENCING)) - method = PNG_FILTER_TYPE_BASE; - -#endif - if (method == PNG_FILTER_TYPE_BASE) - { - switch (filters & (PNG_ALL_FILTERS | 0x07)) - { -#ifdef PNG_WRITE_FILTER_SUPPORTED - case 5: - case 6: - case 7: png_app_error(png_ptr, "Unknown row filter for method 0"); - /* FALL THROUGH */ -#endif /* WRITE_FILTER */ - case PNG_FILTER_VALUE_NONE: - png_ptr->do_filter = PNG_FILTER_NONE; break; - -#ifdef PNG_WRITE_FILTER_SUPPORTED - case PNG_FILTER_VALUE_SUB: - png_ptr->do_filter = PNG_FILTER_SUB; break; - - case PNG_FILTER_VALUE_UP: - png_ptr->do_filter = PNG_FILTER_UP; break; - - case PNG_FILTER_VALUE_AVG: - png_ptr->do_filter = PNG_FILTER_AVG; break; - - case PNG_FILTER_VALUE_PAETH: - png_ptr->do_filter = PNG_FILTER_PAETH; break; - - default: - png_ptr->do_filter = (png_byte)filters; break; -#else - default: - png_app_error(png_ptr, "Unknown row filter for method 0"); -#endif /* WRITE_FILTER */ - } - -#ifdef PNG_WRITE_FILTER_SUPPORTED - /* If we have allocated the row_buf, this means we have already started - * with the image and we should have allocated all of the filter buffers - * that have been selected. If prev_row isn't already allocated, then - * it is too late to start using the filters that need it, since we - * will be missing the data in the previous row. If an application - * wants to start and stop using particular filters during compression, - * it should start out with all of the filters, and then remove them - * or add them back after the start of compression. - * - * NOTE: this is a nasty constraint on the code, because it means that the - * prev_row buffer must be maintained even if there are currently no - * 'prev_row' requiring filters active. - */ - if (png_ptr->row_buf != NULL) - { - int num_filters; - png_alloc_size_t buf_size; - - /* Repeat the checks in png_write_start_row; 1 pixel high or wide - * images cannot benefit from certain filters. If this isn't done here - * the check below will fire on 1 pixel high images. - */ - if (png_ptr->height == 1) - filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); - - if (png_ptr->width == 1) - filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); - - if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0 - && png_ptr->prev_row == NULL) - { - /* This is the error case, however it is benign - the previous row - * is not available so the filter can't be used. Just warn here. - */ - png_app_warning(png_ptr, - "png_set_filter: UP/AVG/PAETH cannot be added after start"); - filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); - } - - num_filters = 0; - - if (filters & PNG_FILTER_SUB) - num_filters++; - - if (filters & PNG_FILTER_UP) - num_filters++; - - if (filters & PNG_FILTER_AVG) - num_filters++; - - if (filters & PNG_FILTER_PAETH) - num_filters++; - - /* Allocate needed row buffers if they have not already been - * allocated. - */ - buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth, - png_ptr->width) + 1; - - if (png_ptr->try_row == NULL) - png_ptr->try_row = png_voidcast(png_bytep, - png_malloc(png_ptr, buf_size)); - - if (num_filters > 1) - { - if (png_ptr->tst_row == NULL) - png_ptr->tst_row = png_voidcast(png_bytep, - png_malloc(png_ptr, buf_size)); - } - } - png_ptr->do_filter = (png_byte)filters; -#endif - } - else - png_error(png_ptr, "Unknown custom filter method"); -} - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ -/* Provide floating and fixed point APIs */ -#ifdef PNG_FLOATING_POINT_SUPPORTED -void PNGAPI -png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method, - int num_weights, png_const_doublep filter_weights, - png_const_doublep filter_costs) -{ - PNG_UNUSED(png_ptr) - PNG_UNUSED(heuristic_method) - PNG_UNUSED(num_weights) - PNG_UNUSED(filter_weights) - PNG_UNUSED(filter_costs) -} -#endif /* FLOATING_POINT */ - -#ifdef PNG_FIXED_POINT_SUPPORTED -void PNGAPI -png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method, - int num_weights, png_const_fixed_point_p filter_weights, - png_const_fixed_point_p filter_costs) -{ - PNG_UNUSED(png_ptr) - PNG_UNUSED(heuristic_method) - PNG_UNUSED(num_weights) - PNG_UNUSED(filter_weights) - PNG_UNUSED(filter_costs) -} -#endif /* FIXED_POINT */ -#endif /* WRITE_WEIGHTED_FILTER */ - -#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED -void PNGAPI -png_set_compression_level(png_structrp png_ptr, int level) -{ - png_debug(1, "in png_set_compression_level"); - - if (png_ptr == NULL) - return; - - png_ptr->zlib_level = level; -} - -void PNGAPI -png_set_compression_mem_level(png_structrp png_ptr, int mem_level) -{ - png_debug(1, "in png_set_compression_mem_level"); - - if (png_ptr == NULL) - return; - - png_ptr->zlib_mem_level = mem_level; -} - -void PNGAPI -png_set_compression_strategy(png_structrp png_ptr, int strategy) -{ - png_debug(1, "in png_set_compression_strategy"); - - if (png_ptr == NULL) - return; - - /* The flag setting here prevents the libpng dynamic selection of strategy. - */ - png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; - png_ptr->zlib_strategy = strategy; -} - -/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a - * smaller value of window_bits if it can do so safely. - */ -void PNGAPI -png_set_compression_window_bits(png_structrp png_ptr, int window_bits) -{ - if (png_ptr == NULL) - return; - - /* Prior to 1.6.0 this would warn but then set the window_bits value. This - * meant that negative window bits values could be selected that would cause - * libpng to write a non-standard PNG file with raw deflate or gzip - * compressed IDAT or ancillary chunks. Such files can be read and there is - * no warning on read, so this seems like a very bad idea. - */ - if (window_bits > 15) - { - png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); - window_bits = 15; - } - - else if (window_bits < 8) - { - png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); - window_bits = 8; - } - - png_ptr->zlib_window_bits = window_bits; -} - -void PNGAPI -png_set_compression_method(png_structrp png_ptr, int method) -{ - png_debug(1, "in png_set_compression_method"); - - if (png_ptr == NULL) - return; - - /* This would produce an invalid PNG file if it worked, but it doesn't and - * deflate will fault it, so it is harmless to just warn here. - */ - if (method != 8) - png_warning(png_ptr, "Only compression method 8 is supported by PNG"); - - png_ptr->zlib_method = method; -} -#endif /* WRITE_CUSTOMIZE_COMPRESSION */ - -/* The following were added to libpng-1.5.4 */ -#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED -void PNGAPI -png_set_text_compression_level(png_structrp png_ptr, int level) -{ - png_debug(1, "in png_set_text_compression_level"); - - if (png_ptr == NULL) - return; - - png_ptr->zlib_text_level = level; -} - -void PNGAPI -png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level) -{ - png_debug(1, "in png_set_text_compression_mem_level"); - - if (png_ptr == NULL) - return; - - png_ptr->zlib_text_mem_level = mem_level; -} - -void PNGAPI -png_set_text_compression_strategy(png_structrp png_ptr, int strategy) -{ - png_debug(1, "in png_set_text_compression_strategy"); - - if (png_ptr == NULL) - return; - - png_ptr->zlib_text_strategy = strategy; -} - -/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a - * smaller value of window_bits if it can do so safely. - */ -void PNGAPI -png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits) -{ - if (png_ptr == NULL) - return; - - if (window_bits > 15) - { - png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); - window_bits = 15; - } - - else if (window_bits < 8) - { - png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); - window_bits = 8; - } - - png_ptr->zlib_text_window_bits = window_bits; -} - -void PNGAPI -png_set_text_compression_method(png_structrp png_ptr, int method) -{ - png_debug(1, "in png_set_text_compression_method"); - - if (png_ptr == NULL) - return; - - if (method != 8) - png_warning(png_ptr, "Only compression method 8 is supported by PNG"); - - png_ptr->zlib_text_method = method; -} -#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ -/* end of API added to libpng-1.5.4 */ - -void PNGAPI -png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn) -{ - if (png_ptr == NULL) - return; - - png_ptr->write_row_fn = write_row_fn; -} - -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED -void PNGAPI -png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr - write_user_transform_fn) -{ - png_debug(1, "in png_set_write_user_transform_fn"); - - if (png_ptr == NULL) - return; - - png_ptr->transformations |= PNG_USER_TRANSFORM; - png_ptr->write_user_transform_fn = write_user_transform_fn; -} -#endif - - -#ifdef PNG_INFO_IMAGE_SUPPORTED -void PNGAPI -png_write_png(png_structrp png_ptr, png_inforp info_ptr, - int transforms, voidp params) -{ - if (png_ptr == NULL || info_ptr == NULL) - return; - - if ((info_ptr->valid & PNG_INFO_IDAT) == 0) - { - png_app_error(png_ptr, "no rows for png_write_image to write"); - return; - } - - /* Write the file header information. */ - png_write_info(png_ptr, info_ptr); - - /* ------ these transformations don't touch the info structure ------- */ - - /* Invert monochrome pixels */ - if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) -#ifdef PNG_WRITE_INVERT_SUPPORTED - png_set_invert_mono(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); -#endif - - /* Shift the pixels up to a legal bit depth and fill in - * as appropriate to correctly scale the image. - */ - if ((transforms & PNG_TRANSFORM_SHIFT) != 0) -#ifdef PNG_WRITE_SHIFT_SUPPORTED - if ((info_ptr->valid & PNG_INFO_sBIT) != 0) - png_set_shift(png_ptr, &info_ptr->sig_bit); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); -#endif - - /* Pack pixels into bytes */ - if ((transforms & PNG_TRANSFORM_PACKING) != 0) -#ifdef PNG_WRITE_PACK_SUPPORTED - png_set_packing(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); -#endif - - /* Swap location of alpha bytes from ARGB to RGBA */ - if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) -#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED - png_set_swap_alpha(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); -#endif - - /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into - * RGB, note that the code expects the input color type to be G or RGB; no - * alpha channel. - */ - if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER| - PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0) - { -#ifdef PNG_WRITE_FILLER_SUPPORTED - if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0) - { - if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) - png_app_error(png_ptr, - "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported"); - - /* Continue if ignored - this is the pre-1.6.10 behavior */ - png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); - } - - else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) - png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported"); -#endif - } - - /* Flip BGR pixels to RGB */ - if ((transforms & PNG_TRANSFORM_BGR) != 0) -#ifdef PNG_WRITE_BGR_SUPPORTED - png_set_bgr(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); -#endif - - /* Swap bytes of 16-bit files to most significant byte first */ - if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) -#ifdef PNG_WRITE_SWAP_SUPPORTED - png_set_swap(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); -#endif - - /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */ - if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) -#ifdef PNG_WRITE_PACKSWAP_SUPPORTED - png_set_packswap(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); -#endif - - /* Invert the alpha channel from opacity to transparency */ - if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) -#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED - png_set_invert_alpha(png_ptr); -#else - png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); -#endif - - /* ----------------------- end of transformations ------------------- */ - - /* Write the bits */ - png_write_image(png_ptr, info_ptr->row_pointers); - - /* It is REQUIRED to call this to finish writing the rest of the file */ - png_write_end(png_ptr, info_ptr); - - PNG_UNUSED(params) -} -#endif - - -#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED -/* Initialize the write structure - general purpose utility. */ -static int -png_image_write_init(png_imagep image) -{ - png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image, - png_safe_error, png_safe_warning); - - if (png_ptr != NULL) - { - png_infop info_ptr = png_create_info_struct(png_ptr); - - if (info_ptr != NULL) - { - png_controlp control = png_voidcast(png_controlp, - png_malloc_warn(png_ptr, (sizeof *control))); - - if (control != NULL) - { - memset(control, 0, (sizeof *control)); - - control->png_ptr = png_ptr; - control->info_ptr = info_ptr; - control->for_write = 1; - - image->opaque = control; - return 1; - } - - /* Error clean up */ - png_destroy_info_struct(png_ptr, &info_ptr); - } - - png_destroy_write_struct(&png_ptr, NULL); - } - - return png_image_error(image, "png_image_write_: out of memory"); -} - -/* Arguments to png_image_write_main: */ -typedef struct -{ - /* Arguments: */ - png_imagep image; - png_const_voidp buffer; - png_int_32 row_stride; - png_const_voidp colormap; - int convert_to_8bit; - /* Local variables: */ - png_const_voidp first_row; - ptrdiff_t row_bytes; - png_voidp local_row; - /* Byte count for memory writing */ - png_bytep memory; - png_alloc_size_t memory_bytes; /* not used for STDIO */ - png_alloc_size_t output_bytes; /* running total */ -} png_image_write_control; - -/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to - * do any necessary byte swapping. The component order is defined by the - * png_image format value. - */ -static int -png_write_image_16bit(png_voidp argument) -{ - png_image_write_control *display = png_voidcast(png_image_write_control*, - argument); - png_imagep image = display->image; - png_structrp png_ptr = image->opaque->png_ptr; - - png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, - display->first_row); - png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row); - png_uint_16p row_end; - const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; - int aindex = 0; - png_uint_32 y = image->height; - - if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) - { -# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED - if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) - { - aindex = -1; - ++input_row; /* To point to the first component */ - ++output_row; - } - else - aindex = channels; -# else - aindex = channels; -# endif - } - - else - png_error(png_ptr, "png_write_image: internal call error"); - - /* Work out the output row end and count over this, note that the increment - * above to 'row' means that row_end can actually be beyond the end of the - * row; this is correct. - */ - row_end = output_row + image->width * (channels+1); - - while (y-- > 0) - { - png_const_uint_16p in_ptr = input_row; - png_uint_16p out_ptr = output_row; - - while (out_ptr < row_end) - { - const png_uint_16 alpha = in_ptr[aindex]; - png_uint_32 reciprocal = 0; - int c; - - out_ptr[aindex] = alpha; - - /* Calculate a reciprocal. The correct calculation is simply - * component/alpha*65535 << 15. (I.e. 15 bits of precision); this - * allows correct rounding by adding .5 before the shift. 'reciprocal' - * is only initialized when required. - */ - if (alpha > 0 && alpha < 65535) - reciprocal = ((0xffff<<15)+(alpha>>1))/alpha; - - c = channels; - do /* always at least one channel */ - { - png_uint_16 component = *in_ptr++; - - /* The following gives 65535 for an alpha of 0, which is fine, - * otherwise if 0/0 is represented as some other value there is more - * likely to be a discontinuity which will probably damage - * compression when moving from a fully transparent area to a - * nearly transparent one. (The assumption here is that opaque - * areas tend not to be 0 intensity.) - */ - if (component >= alpha) - component = 65535; - - /* component<alpha, so component/alpha is less than one and - * component*reciprocal is less than 2^31. - */ - else if (component > 0 && alpha < 65535) - { - png_uint_32 calc = component * reciprocal; - calc += 16384; /* round to nearest */ - component = (png_uint_16)(calc >> 15); - } - - *out_ptr++ = component; - } - while (--c > 0); - - /* Skip to next component (skip the intervening alpha channel) */ - ++in_ptr; - ++out_ptr; - } - - png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row)); - input_row += display->row_bytes/(sizeof (png_uint_16)); - } - - return 1; -} - -/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel - * is present it must be removed from the components, the components are then - * written in sRGB encoding. No components are added or removed. - * - * Calculate an alpha reciprocal to reverse pre-multiplication. As above the - * calculation can be done to 15 bits of accuracy; however, the output needs to - * be scaled in the range 0..255*65535, so include that scaling here. - */ -# define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha) - -static png_byte -png_unpremultiply(png_uint_32 component, png_uint_32 alpha, - png_uint_32 reciprocal/*from the above macro*/) -{ - /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0 - * is represented as some other value there is more likely to be a - * discontinuity which will probably damage compression when moving from a - * fully transparent area to a nearly transparent one. (The assumption here - * is that opaque areas tend not to be 0 intensity.) - * - * There is a rounding problem here; if alpha is less than 128 it will end up - * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the - * output change for this too. - */ - if (component >= alpha || alpha < 128) - return 255; - - /* component<alpha, so component/alpha is less than one and - * component*reciprocal is less than 2^31. - */ - else if (component > 0) - { - /* The test is that alpha/257 (rounded) is less than 255, the first value - * that becomes 255 is 65407. - * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore, - * be exact!) [Could also test reciprocal != 0] - */ - if (alpha < 65407) - { - component *= reciprocal; - component += 64; /* round to nearest */ - component >>= 7; - } - - else - component *= 255; - - /* Convert the component to sRGB. */ - return (png_byte)PNG_sRGB_FROM_LINEAR(component); - } - - else - return 0; -} - -static int -png_write_image_8bit(png_voidp argument) -{ - png_image_write_control *display = png_voidcast(png_image_write_control*, - argument); - png_imagep image = display->image; - png_structrp png_ptr = image->opaque->png_ptr; - - png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, - display->first_row); - png_bytep output_row = png_voidcast(png_bytep, display->local_row); - png_uint_32 y = image->height; - const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; - - if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) - { - png_bytep row_end; - int aindex; - -# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED - if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) - { - aindex = -1; - ++input_row; /* To point to the first component */ - ++output_row; - } - - else -# endif - aindex = channels; - - /* Use row_end in place of a loop counter: */ - row_end = output_row + image->width * (channels+1); - - while (y-- > 0) - { - png_const_uint_16p in_ptr = input_row; - png_bytep out_ptr = output_row; - - while (out_ptr < row_end) - { - png_uint_16 alpha = in_ptr[aindex]; - png_byte alphabyte = (png_byte)PNG_DIV257(alpha); - png_uint_32 reciprocal = 0; - int c; - - /* Scale and write the alpha channel. */ - out_ptr[aindex] = alphabyte; - - if (alphabyte > 0 && alphabyte < 255) - reciprocal = UNP_RECIPROCAL(alpha); - - c = channels; - do /* always at least one channel */ - *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal); - while (--c > 0); - - /* Skip to next component (skip the intervening alpha channel) */ - ++in_ptr; - ++out_ptr; - } /* while out_ptr < row_end */ - - png_write_row(png_ptr, png_voidcast(png_const_bytep, - display->local_row)); - input_row += display->row_bytes/(sizeof (png_uint_16)); - } /* while y */ - } - - else - { - /* No alpha channel, so the row_end really is the end of the row and it - * is sufficient to loop over the components one by one. - */ - png_bytep row_end = output_row + image->width * channels; - - while (y-- > 0) - { - png_const_uint_16p in_ptr = input_row; - png_bytep out_ptr = output_row; - - while (out_ptr < row_end) - { - png_uint_32 component = *in_ptr++; - - component *= 255; - *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component); - } - - png_write_row(png_ptr, output_row); - input_row += display->row_bytes/(sizeof (png_uint_16)); - } - } - - return 1; -} - -static void -png_image_set_PLTE(png_image_write_control *display) -{ - const png_imagep image = display->image; - const void *cmap = display->colormap; - const int entries = image->colormap_entries > 256 ? 256 : - (int)image->colormap_entries; - - /* NOTE: the caller must check for cmap != NULL and entries != 0 */ - const png_uint_32 format = image->format; - const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format); - -# if defined(PNG_FORMAT_BGR_SUPPORTED) &&\ - defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED) - const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 && - (format & PNG_FORMAT_FLAG_ALPHA) != 0; -# else -# define afirst 0 -# endif - -# ifdef PNG_FORMAT_BGR_SUPPORTED - const int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; -# else -# define bgr 0 -# endif - - int i, num_trans; - png_color palette[256]; - png_byte tRNS[256]; - - memset(tRNS, 255, (sizeof tRNS)); - memset(palette, 0, (sizeof palette)); - - for (i=num_trans=0; i<entries; ++i) - { - /* This gets automatically converted to sRGB with reversal of the - * pre-multiplication if the color-map has an alpha channel. - */ - if ((format & PNG_FORMAT_FLAG_LINEAR) != 0) - { - png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap); - - entry += i * channels; - - if ((channels & 1) != 0) /* no alpha */ - { - if (channels >= 3) /* RGB */ - { - palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 * - entry[(2 ^ bgr)]); - palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 * - entry[1]); - palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 * - entry[bgr]); - } - - else /* Gray */ - palette[i].blue = palette[i].red = palette[i].green = - (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry); - } - - else /* alpha */ - { - png_uint_16 alpha = entry[afirst ? 0 : channels-1]; - png_byte alphabyte = (png_byte)PNG_DIV257(alpha); - png_uint_32 reciprocal = 0; - - /* Calculate a reciprocal, as in the png_write_image_8bit code above - * this is designed to produce a value scaled to 255*65535 when - * divided by 128 (i.e. asr 7). - */ - if (alphabyte > 0 && alphabyte < 255) - reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha; - - tRNS[i] = alphabyte; - if (alphabyte < 255) - num_trans = i+1; - - if (channels >= 3) /* RGB */ - { - palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)], - alpha, reciprocal); - palette[i].green = png_unpremultiply(entry[afirst + 1], alpha, - reciprocal); - palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha, - reciprocal); - } - - else /* gray */ - palette[i].blue = palette[i].red = palette[i].green = - png_unpremultiply(entry[afirst], alpha, reciprocal); - } - } - - else /* Color-map has sRGB values */ - { - png_const_bytep entry = png_voidcast(png_const_bytep, cmap); - - entry += i * channels; - - switch (channels) - { - case 4: - tRNS[i] = entry[afirst ? 0 : 3]; - if (tRNS[i] < 255) - num_trans = i+1; - /* FALL THROUGH */ - case 3: - palette[i].blue = entry[afirst + (2 ^ bgr)]; - palette[i].green = entry[afirst + 1]; - palette[i].red = entry[afirst + bgr]; - break; - - case 2: - tRNS[i] = entry[1 ^ afirst]; - if (tRNS[i] < 255) - num_trans = i+1; - /* FALL THROUGH */ - case 1: - palette[i].blue = palette[i].red = palette[i].green = - entry[afirst]; - break; - - default: - break; - } - } - } - -# ifdef afirst -# undef afirst -# endif -# ifdef bgr -# undef bgr -# endif - - png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette, - entries); - - if (num_trans > 0) - png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS, - num_trans, NULL); - - image->colormap_entries = entries; -} - -static int -png_image_write_main(png_voidp argument) -{ - png_image_write_control *display = png_voidcast(png_image_write_control*, - argument); - png_imagep image = display->image; - png_structrp png_ptr = image->opaque->png_ptr; - png_inforp info_ptr = image->opaque->info_ptr; - png_uint_32 format = image->format; - - /* The following four ints are actually booleans */ - int colormap = (format & PNG_FORMAT_FLAG_COLORMAP); - int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */ - int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA); - int write_16bit = linear && !colormap && (display->convert_to_8bit == 0); - -# ifdef PNG_BENIGN_ERRORS_SUPPORTED - /* Make sure we error out on any bad situation */ - png_set_benign_errors(png_ptr, 0/*error*/); -# endif - - /* Default the 'row_stride' parameter if required, also check the row stride - * and total image size to ensure that they are within the system limits. - */ - { - const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); - - if (image->width <= 0x7FFFFFFFU/channels) /* no overflow */ - { - png_uint_32 check; - const png_uint_32 png_row_stride = image->width * channels; - - if (display->row_stride == 0) - display->row_stride = (png_int_32)/*SAFE*/png_row_stride; - - if (display->row_stride < 0) - check = -display->row_stride; - - else - check = display->row_stride; - - if (check >= png_row_stride) - { - /* Now check for overflow of the image buffer calculation; this - * limits the whole image size to 32 bits for API compatibility with - * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. - */ - if (image->height > 0xFFFFFFFF/png_row_stride) - png_error(image->opaque->png_ptr, "memory image too large"); - } - - else - png_error(image->opaque->png_ptr, "supplied row stride too small"); - } - - else - png_error(image->opaque->png_ptr, "image row stride too large"); - } - - /* Set the required transforms then write the rows in the correct order. */ - if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0) - { - if (display->colormap != NULL && image->colormap_entries > 0) - { - png_uint_32 entries = image->colormap_entries; - - png_set_IHDR(png_ptr, info_ptr, image->width, image->height, - entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)), - PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, - PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - - png_image_set_PLTE(display); - } - - else - png_error(image->opaque->png_ptr, - "no color-map for color-mapped image"); - } - - else - png_set_IHDR(png_ptr, info_ptr, image->width, image->height, - write_16bit ? 16 : 8, - ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) + - ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0), - PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - - /* Counter-intuitively the data transformations must be called *after* - * png_write_info, not before as in the read code, but the 'set' functions - * must still be called before. Just set the color space information, never - * write an interlaced image. - */ - - if (write_16bit != 0) - { - /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */ - png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR); - - if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) - png_set_cHRM_fixed(png_ptr, info_ptr, - /* color x y */ - /* white */ 31270, 32900, - /* red */ 64000, 33000, - /* green */ 30000, 60000, - /* blue */ 15000, 6000 - ); - } - - else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) - png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL); - - /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit - * space must still be gamma encoded. - */ - else - png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE); - - /* Write the file header. */ - png_write_info(png_ptr, info_ptr); - - /* Now set up the data transformations (*after* the header is written), - * remove the handled transformations from the 'format' flags for checking. - * - * First check for a little endian system if writing 16-bit files. - */ - if (write_16bit != 0) - { - PNG_CONST png_uint_16 le = 0x0001; - - if ((*(png_const_bytep) & le) != 0) - png_set_swap(png_ptr); - } - -# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED - if ((format & PNG_FORMAT_FLAG_BGR) != 0) - { - if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0) - png_set_bgr(png_ptr); - format &= ~PNG_FORMAT_FLAG_BGR; - } -# endif - -# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED - if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) - { - if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0) - png_set_swap_alpha(png_ptr); - format &= ~PNG_FORMAT_FLAG_AFIRST; - } -# endif - - /* If there are 16 or fewer color-map entries we wrote a lower bit depth - * above, but the application data is still byte packed. - */ - if (colormap != 0 && image->colormap_entries <= 16) - png_set_packing(png_ptr); - - /* That should have handled all (both) the transforms. */ - if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR | - PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0) - png_error(png_ptr, "png_write_image: unsupported transformation"); - - { - png_const_bytep row = png_voidcast(png_const_bytep, display->buffer); - ptrdiff_t row_bytes = display->row_stride; - - if (linear != 0) - row_bytes *= (sizeof (png_uint_16)); - - if (row_bytes < 0) - row += (image->height-1) * (-row_bytes); - - display->first_row = row; - display->row_bytes = row_bytes; - } - - /* Apply 'fast' options if the flag is set. */ - if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0) - { - png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS); - /* NOTE: determined by experiment using pngstest, this reflects some - * balance between the time to write the image once and the time to read - * it about 50 times. The speed-up in pngstest was about 10-20% of the - * total (user) time on a heavily loaded system. - */ -# ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED - png_set_compression_level(png_ptr, 3); -# endif - } - - /* Check for the cases that currently require a pre-transform on the row - * before it is written. This only applies when the input is 16-bit and - * either there is an alpha channel or it is converted to 8-bit. - */ - if ((linear != 0 && alpha != 0 ) || - (colormap == 0 && display->convert_to_8bit != 0)) - { - png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr, - png_get_rowbytes(png_ptr, info_ptr))); - int result; - - display->local_row = row; - if (write_16bit != 0) - result = png_safe_execute(image, png_write_image_16bit, display); - else - result = png_safe_execute(image, png_write_image_8bit, display); - display->local_row = NULL; - - png_free(png_ptr, row); - - /* Skip the 'write_end' on error: */ - if (result == 0) - return 0; - } - - /* Otherwise this is the case where the input is in a format currently - * supported by the rest of the libpng write code; call it directly. - */ - else - { - png_const_bytep row = png_voidcast(png_const_bytep, display->first_row); - ptrdiff_t row_bytes = display->row_bytes; - png_uint_32 y = image->height; - - while (y-- > 0) - { - png_write_row(png_ptr, row); - row += row_bytes; - } - } - - png_write_end(png_ptr, info_ptr); - return 1; -} - - -static void (PNGCBAPI -image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, - png_size_t size) -{ - png_image_write_control *display = png_voidcast(png_image_write_control*, - png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/); - const png_alloc_size_t ob = display->output_bytes; - - /* Check for overflow; this should never happen: */ - if (size <= ((png_alloc_size_t)-1) - ob) - { - /* I don't think libpng ever does this, but just in case: */ - if (size > 0) - { - if (display->memory_bytes >= ob+size) /* writing */ - memcpy(display->memory+ob, data, size); - - /* Always update the size: */ - display->output_bytes = ob+size; - } - } - - else - png_error(png_ptr, "png_image_write_to_memory: PNG too big"); -} - -static void (PNGCBAPI -image_memory_flush)(png_structp png_ptr) -{ - PNG_UNUSED(png_ptr) -} - -static int -png_image_write_memory(png_voidp argument) -{ - png_image_write_control *display = png_voidcast(png_image_write_control*, - argument); - - /* The rest of the memory-specific init and write_main in an error protected - * environment. This case needs to use callbacks for the write operations - * since libpng has no built in support for writing to memory. - */ - png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/, - image_memory_write, image_memory_flush); - - return png_image_write_main(display); -} - -int PNGAPI -png_image_write_to_memory(png_imagep image, void *memory, - png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit, - const void *buffer, png_int_32 row_stride, const void *colormap) -{ - /* Write the image to the given buffer, or count the bytes if it is NULL */ - if (image != NULL && image->version == PNG_IMAGE_VERSION) - { - if (memory_bytes != NULL && buffer != NULL) - { - /* This is to give the caller an easier error detection in the NULL - * case and guard against uninitialized variable problems: - */ - if (memory == NULL) - *memory_bytes = 0; - - if (png_image_write_init(image) != 0) - { - png_image_write_control display; - int result; - - memset(&display, 0, (sizeof display)); - display.image = image; - display.buffer = buffer; - display.row_stride = row_stride; - display.colormap = colormap; - display.convert_to_8bit = convert_to_8bit; - display.memory = png_voidcast(png_bytep, memory); - display.memory_bytes = *memory_bytes; - display.output_bytes = 0; - - result = png_safe_execute(image, png_image_write_memory, &display); - png_image_free(image); - - /* write_memory returns true even if we ran out of buffer. */ - if (result) - { - /* On out-of-buffer this function returns '0' but still updates - * memory_bytes: - */ - if (memory != NULL && display.output_bytes > *memory_bytes) - result = 0; - - *memory_bytes = display.output_bytes; - } - - return result; - } - - else - return 0; - } - - else - return png_image_error(image, - "png_image_write_to_memory: invalid argument"); - } - - else if (image != NULL) - return png_image_error(image, - "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION"); - - else - return 0; -} - -#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED -int PNGAPI -png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit, - const void *buffer, png_int_32 row_stride, const void *colormap) -{ - /* Write the image to the given (FILE*). */ - if (image != NULL && image->version == PNG_IMAGE_VERSION) - { - if (file != NULL && buffer != NULL) - { - if (png_image_write_init(image) != 0) - { - png_image_write_control display; - int result; - - /* This is slightly evil, but png_init_io doesn't do anything other - * than this and we haven't changed the standard IO functions so - * this saves a 'safe' function. - */ - image->opaque->png_ptr->io_ptr = file; - - memset(&display, 0, (sizeof display)); - display.image = image; - display.buffer = buffer; - display.row_stride = row_stride; - display.colormap = colormap; - display.convert_to_8bit = convert_to_8bit; - - result = png_safe_execute(image, png_image_write_main, &display); - png_image_free(image); - return result; - } - - else - return 0; - } - - else - return png_image_error(image, - "png_image_write_to_stdio: invalid argument"); - } - - else if (image != NULL) - return png_image_error(image, - "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION"); - - else - return 0; -} - -int PNGAPI -png_image_write_to_file(png_imagep image, const char *file_name, - int convert_to_8bit, const void *buffer, png_int_32 row_stride, - const void *colormap) -{ - /* Write the image to the named file. */ - if (image != NULL && image->version == PNG_IMAGE_VERSION) - { - if (file_name != NULL && buffer != NULL) - { - FILE *fp = fopen(file_name, "wb"); - - if (fp != NULL) - { - if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer, - row_stride, colormap) != 0) - { - int error; /* from fflush/fclose */ - - /* Make sure the file is flushed correctly. */ - if (fflush(fp) == 0 && ferror(fp) == 0) - { - if (fclose(fp) == 0) - return 1; - - error = errno; /* from fclose */ - } - - else - { - error = errno; /* from fflush or ferror */ - (void)fclose(fp); - } - - (void)remove(file_name); - /* The image has already been cleaned up; this is just used to - * set the error (because the original write succeeded). - */ - return png_image_error(image, strerror(error)); - } - - else - { - /* Clean up: just the opened file. */ - (void)fclose(fp); - (void)remove(file_name); - return 0; - } - } - - else - return png_image_error(image, strerror(errno)); - } - - else - return png_image_error(image, - "png_image_write_to_file: invalid argument"); - } - - else if (image != NULL) - return png_image_error(image, - "png_image_write_to_file: incorrect PNG_IMAGE_VERSION"); - - else - return 0; -} -#endif /* SIMPLIFIED_WRITE_STDIO */ -#endif /* SIMPLIFIED_WRITE */ -#endif /* WRITE */ diff --git a/third_party/libpng/pngwtran.c b/third_party/libpng/pngwtran.c deleted file mode 100644 index 038a2ef5dc..0000000000 --- a/third_party/libpng/pngwtran.c +++ /dev/null @@ -1,576 +0,0 @@ - -/* pngwtran.c - transforms the data in a row for PNG writers - * - * Last changed in libpng 1.6.18 [July 23, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "pngpriv.h" - -#ifdef PNG_WRITE_SUPPORTED -#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED - -#ifdef PNG_WRITE_PACK_SUPPORTED -/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The - * row_info bit depth should be 8 (one pixel per byte). The channels - * should be 1 (this only happens on grayscale and paletted images). - */ -static void -png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) -{ - png_debug(1, "in png_do_pack"); - - if (row_info->bit_depth == 8 && - row_info->channels == 1) - { - switch ((int)bit_depth) - { - case 1: - { - png_bytep sp, dp; - int mask, v; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - sp = row; - dp = row; - mask = 0x80; - v = 0; - - for (i = 0; i < row_width; i++) - { - if (*sp != 0) - v |= mask; - - sp++; - - if (mask > 1) - mask >>= 1; - - else - { - mask = 0x80; - *dp = (png_byte)v; - dp++; - v = 0; - } - } - - if (mask != 0x80) - *dp = (png_byte)v; - - break; - } - - case 2: - { - png_bytep sp, dp; - unsigned int shift; - int v; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - sp = row; - dp = row; - shift = 6; - v = 0; - - for (i = 0; i < row_width; i++) - { - png_byte value; - - value = (png_byte)(*sp & 0x03); - v |= (value << shift); - - if (shift == 0) - { - shift = 6; - *dp = (png_byte)v; - dp++; - v = 0; - } - - else - shift -= 2; - - sp++; - } - - if (shift != 6) - *dp = (png_byte)v; - - break; - } - - case 4: - { - png_bytep sp, dp; - unsigned int shift; - int v; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - sp = row; - dp = row; - shift = 4; - v = 0; - - for (i = 0; i < row_width; i++) - { - png_byte value; - - value = (png_byte)(*sp & 0x0f); - v |= (value << shift); - - if (shift == 0) - { - shift = 4; - *dp = (png_byte)v; - dp++; - v = 0; - } - - else - shift -= 4; - - sp++; - } - - if (shift != 4) - *dp = (png_byte)v; - - break; - } - - default: - break; - } - - row_info->bit_depth = (png_byte)bit_depth; - row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, - row_info->width); - } -} -#endif - -#ifdef PNG_WRITE_SHIFT_SUPPORTED -/* Shift pixel values to take advantage of whole range. Pass the - * true number of bits in bit_depth. The row should be packed - * according to row_info->bit_depth. Thus, if you had a row of - * bit depth 4, but the pixels only had values from 0 to 7, you - * would pass 3 as bit_depth, and this routine would translate the - * data to 0 to 15. - */ -static void -png_do_shift(png_row_infop row_info, png_bytep row, - png_const_color_8p bit_depth) -{ - png_debug(1, "in png_do_shift"); - - if (row_info->color_type != PNG_COLOR_TYPE_PALETTE) - { - int shift_start[4], shift_dec[4]; - int channels = 0; - - if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) - { - shift_start[channels] = row_info->bit_depth - bit_depth->red; - shift_dec[channels] = bit_depth->red; - channels++; - - shift_start[channels] = row_info->bit_depth - bit_depth->green; - shift_dec[channels] = bit_depth->green; - channels++; - - shift_start[channels] = row_info->bit_depth - bit_depth->blue; - shift_dec[channels] = bit_depth->blue; - channels++; - } - - else - { - shift_start[channels] = row_info->bit_depth - bit_depth->gray; - shift_dec[channels] = bit_depth->gray; - channels++; - } - - if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) - { - shift_start[channels] = row_info->bit_depth - bit_depth->alpha; - shift_dec[channels] = bit_depth->alpha; - channels++; - } - - /* With low row depths, could only be grayscale, so one channel */ - if (row_info->bit_depth < 8) - { - png_bytep bp = row; - png_size_t i; - unsigned int mask; - png_size_t row_bytes = row_info->rowbytes; - - if (bit_depth->gray == 1 && row_info->bit_depth == 2) - mask = 0x55; - - else if (row_info->bit_depth == 4 && bit_depth->gray == 3) - mask = 0x11; - - else - mask = 0xff; - - for (i = 0; i < row_bytes; i++, bp++) - { - int j; - unsigned int v, out; - - v = *bp; - out = 0; - - for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0]) - { - if (j > 0) - out |= v << j; - - else - out |= (v >> (-j)) & mask; - } - - *bp = (png_byte)(out & 0xff); - } - } - - else if (row_info->bit_depth == 8) - { - png_bytep bp = row; - png_uint_32 i; - png_uint_32 istop = channels * row_info->width; - - for (i = 0; i < istop; i++, bp++) - { - - const unsigned int c = i%channels; - int j; - unsigned int v, out; - - v = *bp; - out = 0; - - for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) - { - if (j > 0) - out |= v << j; - - else - out |= v >> (-j); - } - - *bp = (png_byte)(out & 0xff); - } - } - - else - { - png_bytep bp; - png_uint_32 i; - png_uint_32 istop = channels * row_info->width; - - for (bp = row, i = 0; i < istop; i++) - { - const unsigned int c = i%channels; - int j; - unsigned int value, v; - - v = png_get_uint_16(bp); - value = 0; - - for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) - { - if (j > 0) - value |= v << j; - - else - value |= v >> (-j); - } - *bp++ = (png_byte)((value >> 8) & 0xff); - *bp++ = (png_byte)(value & 0xff); - } - } - } -} -#endif - -#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED -static void -png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_write_swap_alpha"); - - { - if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - { - if (row_info->bit_depth == 8) - { - /* This converts from ARGB to RGBA */ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - for (i = 0, sp = dp = row; i < row_width; i++) - { - png_byte save = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = save; - } - } - -#ifdef PNG_WRITE_16BIT_SUPPORTED - else - { - /* This converts from AARRGGBB to RRGGBBAA */ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - for (i = 0, sp = dp = row; i < row_width; i++) - { - png_byte save[2]; - save[0] = *(sp++); - save[1] = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = save[0]; - *(dp++) = save[1]; - } - } -#endif /* WRITE_16BIT */ - } - - else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - { - if (row_info->bit_depth == 8) - { - /* This converts from AG to GA */ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - for (i = 0, sp = dp = row; i < row_width; i++) - { - png_byte save = *(sp++); - *(dp++) = *(sp++); - *(dp++) = save; - } - } - -#ifdef PNG_WRITE_16BIT_SUPPORTED - else - { - /* This converts from AAGG to GGAA */ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - for (i = 0, sp = dp = row; i < row_width; i++) - { - png_byte save[2]; - save[0] = *(sp++); - save[1] = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = save[0]; - *(dp++) = save[1]; - } - } -#endif /* WRITE_16BIT */ - } - } -} -#endif - -#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED -static void -png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) -{ - png_debug(1, "in png_do_write_invert_alpha"); - - { - if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) - { - if (row_info->bit_depth == 8) - { - /* This inverts the alpha channel in RGBA */ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - for (i = 0, sp = dp = row; i < row_width; i++) - { - /* Does nothing - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - */ - sp+=3; dp = sp; - *dp = (png_byte)(255 - *(sp++)); - } - } - -#ifdef PNG_WRITE_16BIT_SUPPORTED - else - { - /* This inverts the alpha channel in RRGGBBAA */ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - for (i = 0, sp = dp = row; i < row_width; i++) - { - /* Does nothing - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - *(dp++) = *(sp++); - */ - sp+=6; dp = sp; - *(dp++) = (png_byte)(255 - *(sp++)); - *dp = (png_byte)(255 - *(sp++)); - } - } -#endif /* WRITE_16BIT */ - } - - else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - { - if (row_info->bit_depth == 8) - { - /* This inverts the alpha channel in GA */ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - for (i = 0, sp = dp = row; i < row_width; i++) - { - *(dp++) = *(sp++); - *(dp++) = (png_byte)(255 - *(sp++)); - } - } - -#ifdef PNG_WRITE_16BIT_SUPPORTED - else - { - /* This inverts the alpha channel in GGAA */ - png_bytep sp, dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - for (i = 0, sp = dp = row; i < row_width; i++) - { - /* Does nothing - *(dp++) = *(sp++); - *(dp++) = *(sp++); - */ - sp+=2; dp = sp; - *(dp++) = (png_byte)(255 - *(sp++)); - *dp = (png_byte)(255 - *(sp++)); - } - } -#endif /* WRITE_16BIT */ - } - } -} -#endif - -/* Transform the data according to the user's wishes. The order of - * transformations is significant. - */ -void /* PRIVATE */ -png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info) -{ - png_debug(1, "in png_do_write_transformations"); - - if (png_ptr == NULL) - return; - -#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED - if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) - if (png_ptr->write_user_transform_fn != NULL) - (*(png_ptr->write_user_transform_fn)) /* User write transform - function */ - (png_ptr, /* png_ptr */ - row_info, /* row_info: */ - /* png_uint_32 width; width of row */ - /* png_size_t rowbytes; number of bytes in row */ - /* png_byte color_type; color type of pixels */ - /* png_byte bit_depth; bit depth of samples */ - /* png_byte channels; number of channels (1-4) */ - /* png_byte pixel_depth; bits per pixel (depth*channels) */ - png_ptr->row_buf + 1); /* start of pixel data for row */ -#endif - -#ifdef PNG_WRITE_FILLER_SUPPORTED - if ((png_ptr->transformations & PNG_FILLER) != 0) - png_do_strip_channel(row_info, png_ptr->row_buf + 1, - !(png_ptr->flags & PNG_FLAG_FILLER_AFTER)); -#endif - -#ifdef PNG_WRITE_PACKSWAP_SUPPORTED - if ((png_ptr->transformations & PNG_PACKSWAP) != 0) - png_do_packswap(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_WRITE_PACK_SUPPORTED - if ((png_ptr->transformations & PNG_PACK) != 0) - png_do_pack(row_info, png_ptr->row_buf + 1, - (png_uint_32)png_ptr->bit_depth); -#endif - -#ifdef PNG_WRITE_SWAP_SUPPORTED -# ifdef PNG_16BIT_SUPPORTED - if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) - png_do_swap(row_info, png_ptr->row_buf + 1); -# endif -#endif - -#ifdef PNG_WRITE_SHIFT_SUPPORTED - if ((png_ptr->transformations & PNG_SHIFT) != 0) - png_do_shift(row_info, png_ptr->row_buf + 1, - &(png_ptr->shift)); -#endif - -#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0) - png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED - if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) - png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_WRITE_BGR_SUPPORTED - if ((png_ptr->transformations & PNG_BGR) != 0) - png_do_bgr(row_info, png_ptr->row_buf + 1); -#endif - -#ifdef PNG_WRITE_INVERT_SUPPORTED - if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) - png_do_invert(row_info, png_ptr->row_buf + 1); -#endif -} -#endif /* WRITE_TRANSFORMS */ -#endif /* WRITE */ diff --git a/third_party/libpng/pngwutil.c b/third_party/libpng/pngwutil.c deleted file mode 100644 index 494169051c..0000000000 --- a/third_party/libpng/pngwutil.c +++ /dev/null @@ -1,2625 +0,0 @@ - -/* pngwutil.c - utilities to write a PNG file - * - * Last changed in libpng 1.6.22 [(PENDING RELEASE)] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "pngpriv.h" - -#ifdef PNG_WRITE_SUPPORTED - -#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED -/* Place a 32-bit number into a buffer in PNG byte order. We work - * with unsigned numbers for convenience, although one supported - * ancillary chunk uses signed (two's complement) numbers. - */ -void PNGAPI -png_save_uint_32(png_bytep buf, png_uint_32 i) -{ - buf[0] = (png_byte)((i >> 24) & 0xffU); - buf[1] = (png_byte)((i >> 16) & 0xffU); - buf[2] = (png_byte)((i >> 8) & 0xffU); - buf[3] = (png_byte)( i & 0xffU); -} - -/* Place a 16-bit number into a buffer in PNG byte order. - * The parameter is declared unsigned int, not png_uint_16, - * just to avoid potential problems on pre-ANSI C compilers. - */ -void PNGAPI -png_save_uint_16(png_bytep buf, unsigned int i) -{ - buf[0] = (png_byte)((i >> 8) & 0xffU); - buf[1] = (png_byte)( i & 0xffU); -} -#endif - -/* Simple function to write the signature. If we have already written - * the magic bytes of the signature, or more likely, the PNG stream is - * being embedded into another stream and doesn't need its own signature, - * we should call png_set_sig_bytes() to tell libpng how many of the - * bytes have already been written. - */ -void PNGAPI -png_write_sig(png_structrp png_ptr) -{ - png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the signature is being written */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; -#endif - - /* Write the rest of the 8 byte signature */ - png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], - (png_size_t)(8 - png_ptr->sig_bytes)); - - if (png_ptr->sig_bytes < 3) - png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; -} - -/* Write the start of a PNG chunk. The type is the chunk type. - * The total_length is the sum of the lengths of all the data you will be - * passing in png_write_chunk_data(). - */ -static void -png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name, - png_uint_32 length) -{ - png_byte buf[8]; - -#if defined(PNG_DEBUG) && (PNG_DEBUG > 0) - PNG_CSTRING_FROM_CHUNK(buf, chunk_name); - png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length); -#endif - - if (png_ptr == NULL) - return; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the chunk header is being written. - * PNG_IO_CHUNK_HDR requires a single I/O call. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; -#endif - - /* Write the length and the chunk name */ - png_save_uint_32(buf, length); - png_save_uint_32(buf + 4, chunk_name); - png_write_data(png_ptr, buf, 8); - - /* Put the chunk name into png_ptr->chunk_name */ - png_ptr->chunk_name = chunk_name; - - /* Reset the crc and run it over the chunk name */ - png_reset_crc(png_ptr); - - png_calculate_crc(png_ptr, buf + 4, 4); - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that chunk data will (possibly) be written. - * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; -#endif -} - -void PNGAPI -png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string, - png_uint_32 length) -{ - png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length); -} - -/* Write the data of a PNG chunk started with png_write_chunk_header(). - * Note that multiple calls to this function are allowed, and that the - * sum of the lengths from these calls *must* add up to the total_length - * given to png_write_chunk_header(). - */ -void PNGAPI -png_write_chunk_data(png_structrp png_ptr, png_const_bytep data, - png_size_t length) -{ - /* Write the data, and run the CRC over it */ - if (png_ptr == NULL) - return; - - if (data != NULL && length > 0) - { - png_write_data(png_ptr, data, length); - - /* Update the CRC after writing the data, - * in case the user I/O routine alters it. - */ - png_calculate_crc(png_ptr, data, length); - } -} - -/* Finish a chunk started with png_write_chunk_header(). */ -void PNGAPI -png_write_chunk_end(png_structrp png_ptr) -{ - png_byte buf[4]; - - if (png_ptr == NULL) return; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the chunk CRC is being written. - * PNG_IO_CHUNK_CRC requires a single I/O function call. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; -#endif - - /* Write the crc in a single operation */ - png_save_uint_32(buf, png_ptr->crc); - - png_write_data(png_ptr, buf, (png_size_t)4); -} - -/* Write a PNG chunk all at once. The type is an array of ASCII characters - * representing the chunk name. The array must be at least 4 bytes in - * length, and does not need to be null terminated. To be safe, pass the - * pre-defined chunk names here, and if you need a new one, define it - * where the others are defined. The length is the length of the data. - * All the data must be present. If that is not possible, use the - * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() - * functions instead. - */ -static void -png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name, - png_const_bytep data, png_size_t length) -{ - if (png_ptr == NULL) - return; - - /* On 64-bit architectures 'length' may not fit in a png_uint_32. */ - if (length > PNG_UINT_31_MAX) - png_error(png_ptr, "length exceeds PNG maximum"); - - png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length); - png_write_chunk_data(png_ptr, data, length); - png_write_chunk_end(png_ptr); -} - -/* This is the API that calls the internal function above. */ -void PNGAPI -png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string, - png_const_bytep data, png_size_t length) -{ - png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data, - length); -} - -/* This is used below to find the size of an image to pass to png_deflate_claim, - * so it only needs to be accurate if the size is less than 16384 bytes (the - * point at which a lower LZ window size can be used.) - */ -static png_alloc_size_t -png_image_size(png_structrp png_ptr) -{ - /* Only return sizes up to the maximum of a png_uint_32; do this by limiting - * the width and height used to 15 bits. - */ - png_uint_32 h = png_ptr->height; - - if (png_ptr->rowbytes < 32768 && h < 32768) - { - if (png_ptr->interlaced != 0) - { - /* Interlacing makes the image larger because of the replication of - * both the filter byte and the padding to a byte boundary. - */ - png_uint_32 w = png_ptr->width; - unsigned int pd = png_ptr->pixel_depth; - png_alloc_size_t cb_base; - int pass; - - for (cb_base=0, pass=0; pass<=6; ++pass) - { - png_uint_32 pw = PNG_PASS_COLS(w, pass); - - if (pw > 0) - cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass); - } - - return cb_base; - } - - else - return (png_ptr->rowbytes+1) * h; - } - - else - return 0xffffffffU; -} - -#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - /* This is the code to hack the first two bytes of the deflate stream (the - * deflate header) to correct the windowBits value to match the actual data - * size. Note that the second argument is the *uncompressed* size but the - * first argument is the *compressed* data (and it must be deflate - * compressed.) - */ -static void -optimize_cmf(png_bytep data, png_alloc_size_t data_size) -{ - /* Optimize the CMF field in the zlib stream. The resultant zlib stream is - * still compliant to the stream specification. - */ - if (data_size <= 16384) /* else windowBits must be 15 */ - { - unsigned int z_cmf = data[0]; /* zlib compression method and flags */ - - if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) - { - unsigned int z_cinfo; - unsigned int half_z_window_size; - - z_cinfo = z_cmf >> 4; - half_z_window_size = 1U << (z_cinfo + 7); - - if (data_size <= half_z_window_size) /* else no change */ - { - unsigned int tmp; - - do - { - half_z_window_size >>= 1; - --z_cinfo; - } - while (z_cinfo > 0 && data_size <= half_z_window_size); - - z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); - - data[0] = (png_byte)z_cmf; - tmp = data[1] & 0xe0; - tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; - data[1] = (png_byte)tmp; - } - } - } -} -#endif /* WRITE_OPTIMIZE_CMF */ - -/* Initialize the compressor for the appropriate type of compression. */ -static int -png_deflate_claim(png_structrp png_ptr, png_uint_32 owner, - png_alloc_size_t data_size) -{ - if (png_ptr->zowner != 0) - { -#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED) - char msg[64]; - - PNG_STRING_FROM_CHUNK(msg, owner); - msg[4] = ':'; - msg[5] = ' '; - PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner); - /* So the message that results is "<chunk> using zstream"; this is an - * internal error, but is very useful for debugging. i18n requirements - * are minimal. - */ - (void)png_safecat(msg, (sizeof msg), 10, " using zstream"); -#endif -#if PNG_RELEASE_BUILD - png_warning(png_ptr, msg); - - /* Attempt sane error recovery */ - if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */ - { - png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT"); - return Z_STREAM_ERROR; - } - - png_ptr->zowner = 0; -#else - png_error(png_ptr, msg); -#endif - } - - { - int level = png_ptr->zlib_level; - int method = png_ptr->zlib_method; - int windowBits = png_ptr->zlib_window_bits; - int memLevel = png_ptr->zlib_mem_level; - int strategy; /* set below */ - int ret; /* zlib return code */ - - if (owner == png_IDAT) - { - if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0) - strategy = png_ptr->zlib_strategy; - - else if (png_ptr->do_filter != PNG_FILTER_NONE) - strategy = PNG_Z_DEFAULT_STRATEGY; - - else - strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY; - } - - else - { -#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED - level = png_ptr->zlib_text_level; - method = png_ptr->zlib_text_method; - windowBits = png_ptr->zlib_text_window_bits; - memLevel = png_ptr->zlib_text_mem_level; - strategy = png_ptr->zlib_text_strategy; -#else - /* If customization is not supported the values all come from the - * IDAT values except for the strategy, which is fixed to the - * default. (This is the pre-1.6.0 behavior too, although it was - * implemented in a very different way.) - */ - strategy = Z_DEFAULT_STRATEGY; -#endif - } - - /* Adjust 'windowBits' down if larger than 'data_size'; to stop this - * happening just pass 32768 as the data_size parameter. Notice that zlib - * requires an extra 262 bytes in the window in addition to the data to be - * able to see the whole of the data, so if data_size+262 takes us to the - * next windowBits size we need to fix up the value later. (Because even - * though deflate needs the extra window, inflate does not!) - */ - if (data_size <= 16384) - { - /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to - * work round a Microsoft Visual C misbehavior which, contrary to C-90, - * widens the result of the following shift to 64-bits if (and, - * apparently, only if) it is used in a test. - */ - unsigned int half_window_size = 1U << (windowBits-1); - - while (data_size + 262 <= half_window_size) - { - half_window_size >>= 1; - --windowBits; - } - } - - /* Check against the previous initialized values, if any. */ - if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0 && - (png_ptr->zlib_set_level != level || - png_ptr->zlib_set_method != method || - png_ptr->zlib_set_window_bits != windowBits || - png_ptr->zlib_set_mem_level != memLevel || - png_ptr->zlib_set_strategy != strategy)) - { - if (deflateEnd(&png_ptr->zstream) != Z_OK) - png_warning(png_ptr, "deflateEnd failed (ignored)"); - - png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED; - } - - /* For safety clear out the input and output pointers (currently zlib - * doesn't use them on Init, but it might in the future). - */ - png_ptr->zstream.next_in = NULL; - png_ptr->zstream.avail_in = 0; - png_ptr->zstream.next_out = NULL; - png_ptr->zstream.avail_out = 0; - - /* Now initialize if required, setting the new parameters, otherwise just - * to a simple reset to the previous parameters. - */ - if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) - ret = deflateReset(&png_ptr->zstream); - - else - { - ret = deflateInit2(&png_ptr->zstream, level, method, windowBits, - memLevel, strategy); - - if (ret == Z_OK) - png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; - } - - /* The return code is from either deflateReset or deflateInit2; they have - * pretty much the same set of error codes. - */ - if (ret == Z_OK) - png_ptr->zowner = owner; - - else - png_zstream_error(png_ptr, ret); - - return ret; - } -} - -/* Clean up (or trim) a linked list of compression buffers. */ -void /* PRIVATE */ -png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp) -{ - png_compression_bufferp list = *listp; - - if (list != NULL) - { - *listp = NULL; - - do - { - png_compression_bufferp next = list->next; - - png_free(png_ptr, list); - list = next; - } - while (list != NULL); - } -} - -#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED -/* This pair of functions encapsulates the operation of (a) compressing a - * text string, and (b) issuing it later as a series of chunk data writes. - * The compression_state structure is shared context for these functions - * set up by the caller to allow access to the relevant local variables. - * - * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size - * temporary buffers. From 1.6.0 it is retained in png_struct so that it will - * be correctly freed in the event of a write error (previous implementations - * just leaked memory.) - */ -typedef struct -{ - png_const_bytep input; /* The uncompressed input data */ - png_alloc_size_t input_len; /* Its length */ - png_uint_32 output_len; /* Final compressed length */ - png_byte output[1024]; /* First block of output */ -} compression_state; - -static void -png_text_compress_init(compression_state *comp, png_const_bytep input, - png_alloc_size_t input_len) -{ - comp->input = input; - comp->input_len = input_len; - comp->output_len = 0; -} - -/* Compress the data in the compression state input */ -static int -png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name, - compression_state *comp, png_uint_32 prefix_len) -{ - int ret; - - /* To find the length of the output it is necessary to first compress the - * input. The result is buffered rather than using the two-pass algorithm - * that is used on the inflate side; deflate is assumed to be slower and a - * PNG writer is assumed to have more memory available than a PNG reader. - * - * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an - * upper limit on the output size, but it is always bigger than the input - * size so it is likely to be more efficient to use this linked-list - * approach. - */ - ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len); - - if (ret != Z_OK) - return ret; - - /* Set up the compression buffers, we need a loop here to avoid overflowing a - * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited - * by the output buffer size, so there is no need to check that. Since this - * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits - * in size. - */ - { - png_compression_bufferp *end = &png_ptr->zbuffer_list; - png_alloc_size_t input_len = comp->input_len; /* may be zero! */ - png_uint_32 output_len; - - /* zlib updates these for us: */ - png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input); - png_ptr->zstream.avail_in = 0; /* Set below */ - png_ptr->zstream.next_out = comp->output; - png_ptr->zstream.avail_out = (sizeof comp->output); - - output_len = png_ptr->zstream.avail_out; - - do - { - uInt avail_in = ZLIB_IO_MAX; - - if (avail_in > input_len) - avail_in = (uInt)input_len; - - input_len -= avail_in; - - png_ptr->zstream.avail_in = avail_in; - - if (png_ptr->zstream.avail_out == 0) - { - png_compression_buffer *next; - - /* Chunk data is limited to 2^31 bytes in length, so the prefix - * length must be counted here. - */ - if (output_len + prefix_len > PNG_UINT_31_MAX) - { - ret = Z_MEM_ERROR; - break; - } - - /* Need a new (malloc'ed) buffer, but there may be one present - * already. - */ - next = *end; - if (next == NULL) - { - next = png_voidcast(png_compression_bufferp, png_malloc_base - (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); - - if (next == NULL) - { - ret = Z_MEM_ERROR; - break; - } - - /* Link in this buffer (so that it will be freed later) */ - next->next = NULL; - *end = next; - } - - png_ptr->zstream.next_out = next->output; - png_ptr->zstream.avail_out = png_ptr->zbuffer_size; - output_len += png_ptr->zstream.avail_out; - - /* Move 'end' to the next buffer pointer. */ - end = &next->next; - } - - /* Compress the data */ - ret = deflate(&png_ptr->zstream, - input_len > 0 ? Z_NO_FLUSH : Z_FINISH); - - /* Claw back input data that was not consumed (because avail_in is - * reset above every time round the loop). - */ - input_len += png_ptr->zstream.avail_in; - png_ptr->zstream.avail_in = 0; /* safety */ - } - while (ret == Z_OK); - - /* There may be some space left in the last output buffer. This needs to - * be subtracted from output_len. - */ - output_len -= png_ptr->zstream.avail_out; - png_ptr->zstream.avail_out = 0; /* safety */ - comp->output_len = output_len; - - /* Now double check the output length, put in a custom message if it is - * too long. Otherwise ensure the z_stream::msg pointer is set to - * something. - */ - if (output_len + prefix_len >= PNG_UINT_31_MAX) - { - png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long"); - ret = Z_MEM_ERROR; - } - - else - png_zstream_error(png_ptr, ret); - - /* Reset zlib for another zTXt/iTXt or image data */ - png_ptr->zowner = 0; - - /* The only success case is Z_STREAM_END, input_len must be 0; if not this - * is an internal error. - */ - if (ret == Z_STREAM_END && input_len == 0) - { -#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - /* Fix up the deflate header, if required */ - optimize_cmf(comp->output, comp->input_len); -#endif - /* But Z_OK is returned, not Z_STREAM_END; this allows the claim - * function above to return Z_STREAM_END on an error (though it never - * does in the current versions of zlib.) - */ - return Z_OK; - } - - else - return ret; - } -} - -/* Ship the compressed text out via chunk writes */ -static void -png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp) -{ - png_uint_32 output_len = comp->output_len; - png_const_bytep output = comp->output; - png_uint_32 avail = (sizeof comp->output); - png_compression_buffer *next = png_ptr->zbuffer_list; - - for (;;) - { - if (avail > output_len) - avail = output_len; - - png_write_chunk_data(png_ptr, output, avail); - - output_len -= avail; - - if (output_len == 0 || next == NULL) - break; - - avail = png_ptr->zbuffer_size; - output = next->output; - next = next->next; - } - - /* This is an internal error; 'next' must have been NULL! */ - if (output_len > 0) - png_error(png_ptr, "error writing ancillary chunked compressed data"); -} -#endif /* WRITE_COMPRESSED_TEXT */ - -/* Write the IHDR chunk, and update the png_struct with the necessary - * information. Note that the rest of this code depends upon this - * information being correct. - */ -void /* PRIVATE */ -png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height, - int bit_depth, int color_type, int compression_type, int filter_type, - int interlace_type) -{ - png_byte buf[13]; /* Buffer to store the IHDR info */ - - png_debug(1, "in png_write_IHDR"); - - /* Check that we have valid input data from the application info */ - switch (color_type) - { - case PNG_COLOR_TYPE_GRAY: - switch (bit_depth) - { - case 1: - case 2: - case 4: - case 8: -#ifdef PNG_WRITE_16BIT_SUPPORTED - case 16: -#endif - png_ptr->channels = 1; break; - - default: - png_error(png_ptr, - "Invalid bit depth for grayscale image"); - } - break; - - case PNG_COLOR_TYPE_RGB: -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (bit_depth != 8 && bit_depth != 16) -#else - if (bit_depth != 8) -#endif - png_error(png_ptr, "Invalid bit depth for RGB image"); - - png_ptr->channels = 3; - break; - - case PNG_COLOR_TYPE_PALETTE: - switch (bit_depth) - { - case 1: - case 2: - case 4: - case 8: - png_ptr->channels = 1; - break; - - default: - png_error(png_ptr, "Invalid bit depth for paletted image"); - } - break; - - case PNG_COLOR_TYPE_GRAY_ALPHA: - if (bit_depth != 8 && bit_depth != 16) - png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); - - png_ptr->channels = 2; - break; - - case PNG_COLOR_TYPE_RGB_ALPHA: -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (bit_depth != 8 && bit_depth != 16) -#else - if (bit_depth != 8) -#endif - png_error(png_ptr, "Invalid bit depth for RGBA image"); - - png_ptr->channels = 4; - break; - - default: - png_error(png_ptr, "Invalid image color type specified"); - } - - if (compression_type != PNG_COMPRESSION_TYPE_BASE) - { - png_warning(png_ptr, "Invalid compression type specified"); - compression_type = PNG_COMPRESSION_TYPE_BASE; - } - - /* Write filter_method 64 (intrapixel differencing) only if - * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and - * 2. Libpng did not write a PNG signature (this filter_method is only - * used in PNG datastreams that are embedded in MNG datastreams) and - * 3. The application called png_permit_mng_features with a mask that - * included PNG_FLAG_MNG_FILTER_64 and - * 4. The filter_method is 64 and - * 5. The color_type is RGB or RGBA - */ - if ( -#ifdef PNG_MNG_FEATURES_SUPPORTED - !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && - ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) && - (color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_RGB_ALPHA) && - (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && -#endif - filter_type != PNG_FILTER_TYPE_BASE) - { - png_warning(png_ptr, "Invalid filter type specified"); - filter_type = PNG_FILTER_TYPE_BASE; - } - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - if (interlace_type != PNG_INTERLACE_NONE && - interlace_type != PNG_INTERLACE_ADAM7) - { - png_warning(png_ptr, "Invalid interlace type specified"); - interlace_type = PNG_INTERLACE_ADAM7; - } -#else - interlace_type=PNG_INTERLACE_NONE; -#endif - - /* Save the relevant information */ - png_ptr->bit_depth = (png_byte)bit_depth; - png_ptr->color_type = (png_byte)color_type; - png_ptr->interlaced = (png_byte)interlace_type; -#ifdef PNG_MNG_FEATURES_SUPPORTED - png_ptr->filter_type = (png_byte)filter_type; -#endif - png_ptr->compression_type = (png_byte)compression_type; - png_ptr->width = width; - png_ptr->height = height; - - png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); - png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); - /* Set the usr info, so any transformations can modify it */ - png_ptr->usr_width = png_ptr->width; - png_ptr->usr_bit_depth = png_ptr->bit_depth; - png_ptr->usr_channels = png_ptr->channels; - - /* Pack the header information into the buffer */ - png_save_uint_32(buf, width); - png_save_uint_32(buf + 4, height); - buf[8] = (png_byte)bit_depth; - buf[9] = (png_byte)color_type; - buf[10] = (png_byte)compression_type; - buf[11] = (png_byte)filter_type; - buf[12] = (png_byte)interlace_type; - - /* Write the chunk */ - png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); - - if ((png_ptr->do_filter) == PNG_NO_FILTERS) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || - png_ptr->bit_depth < 8) - png_ptr->do_filter = PNG_FILTER_NONE; - - else - png_ptr->do_filter = PNG_ALL_FILTERS; - } - - png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */ -} - -/* Write the palette. We are careful not to trust png_color to be in the - * correct order for PNG, so people can redefine it to any convenient - * structure. - */ -void /* PRIVATE */ -png_write_PLTE(png_structrp png_ptr, png_const_colorp palette, - png_uint_32 num_pal) -{ - png_uint_32 max_palette_length, i; - png_const_colorp pal_ptr; - png_byte buf[3]; - - png_debug(1, "in png_write_PLTE"); - - max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ? - (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH; - - if (( -#ifdef PNG_MNG_FEATURES_SUPPORTED - (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 && -#endif - num_pal == 0) || num_pal > max_palette_length) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - png_error(png_ptr, "Invalid number of colors in palette"); - } - - else - { - png_warning(png_ptr, "Invalid number of colors in palette"); - return; - } - } - - if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) - { - png_warning(png_ptr, - "Ignoring request to write a PLTE chunk in grayscale PNG"); - - return; - } - - png_ptr->num_palette = (png_uint_16)num_pal; - png_debug1(3, "num_palette = %d", png_ptr->num_palette); - - png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); -#ifdef PNG_POINTER_INDEXING_SUPPORTED - - for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) - { - buf[0] = pal_ptr->red; - buf[1] = pal_ptr->green; - buf[2] = pal_ptr->blue; - png_write_chunk_data(png_ptr, buf, (png_size_t)3); - } - -#else - /* This is a little slower but some buggy compilers need to do this - * instead - */ - pal_ptr=palette; - - for (i = 0; i < num_pal; i++) - { - buf[0] = pal_ptr[i].red; - buf[1] = pal_ptr[i].green; - buf[2] = pal_ptr[i].blue; - png_write_chunk_data(png_ptr, buf, (png_size_t)3); - } - -#endif - png_write_chunk_end(png_ptr); - png_ptr->mode |= PNG_HAVE_PLTE; -} - -/* This is similar to png_text_compress, above, except that it does not require - * all of the data at once and, instead of buffering the compressed result, - * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out - * because it calls the write interface. As a result it does its own error - * reporting and does not return an error code. In the event of error it will - * just call png_error. The input data length may exceed 32-bits. The 'flush' - * parameter is exactly the same as that to deflate, with the following - * meanings: - * - * Z_NO_FLUSH: normal incremental output of compressed data - * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush - * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up - * - * The routine manages the acquire and release of the png_ptr->zstream by - * checking and (at the end) clearing png_ptr->zowner; it does some sanity - * checks on the 'mode' flags while doing this. - */ -void /* PRIVATE */ -png_compress_IDAT(png_structrp png_ptr, png_const_bytep input, - png_alloc_size_t input_len, int flush) -{ - if (png_ptr->zowner != png_IDAT) - { - /* First time. Ensure we have a temporary buffer for compression and - * trim the buffer list if it has more than one entry to free memory. - * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been - * created at this point, but the check here is quick and safe. - */ - if (png_ptr->zbuffer_list == NULL) - { - png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp, - png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); - png_ptr->zbuffer_list->next = NULL; - } - - else - png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next); - - /* It is a terminal error if we can't claim the zstream. */ - if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - - /* The output state is maintained in png_ptr->zstream, so it must be - * initialized here after the claim. - */ - png_ptr->zstream.next_out = png_ptr->zbuffer_list->output; - png_ptr->zstream.avail_out = png_ptr->zbuffer_size; - } - - /* Now loop reading and writing until all the input is consumed or an error - * terminates the operation. The _out values are maintained across calls to - * this function, but the input must be reset each time. - */ - png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); - png_ptr->zstream.avail_in = 0; /* set below */ - for (;;) - { - int ret; - - /* INPUT: from the row data */ - uInt avail = ZLIB_IO_MAX; - - if (avail > input_len) - avail = (uInt)input_len; /* safe because of the check */ - - png_ptr->zstream.avail_in = avail; - input_len -= avail; - - ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush); - - /* Include as-yet unconsumed input */ - input_len += png_ptr->zstream.avail_in; - png_ptr->zstream.avail_in = 0; - - /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note - * that these two zstream fields are preserved across the calls, therefore - * there is no need to set these up on entry to the loop. - */ - if (png_ptr->zstream.avail_out == 0) - { - png_bytep data = png_ptr->zbuffer_list->output; - uInt size = png_ptr->zbuffer_size; - - /* Write an IDAT containing the data then reset the buffer. The - * first IDAT may need deflate header optimization. - */ -#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 && - png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) - optimize_cmf(data, png_image_size(png_ptr)); -#endif - - png_write_complete_chunk(png_ptr, png_IDAT, data, size); - png_ptr->mode |= PNG_HAVE_IDAT; - - png_ptr->zstream.next_out = data; - png_ptr->zstream.avail_out = size; - - /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with - * the same flush parameter until it has finished output, for NO_FLUSH - * it doesn't matter. - */ - if (ret == Z_OK && flush != Z_NO_FLUSH) - continue; - } - - /* The order of these checks doesn't matter much; it just affects which - * possible error might be detected if multiple things go wrong at once. - */ - if (ret == Z_OK) /* most likely return code! */ - { - /* If all the input has been consumed then just return. If Z_FINISH - * was used as the flush parameter something has gone wrong if we get - * here. - */ - if (input_len == 0) - { - if (flush == Z_FINISH) - png_error(png_ptr, "Z_OK on Z_FINISH with output space"); - - return; - } - } - - else if (ret == Z_STREAM_END && flush == Z_FINISH) - { - /* This is the end of the IDAT data; any pending output must be - * flushed. For small PNG files we may still be at the beginning. - */ - png_bytep data = png_ptr->zbuffer_list->output; - uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out; - -#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 && - png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) - optimize_cmf(data, png_image_size(png_ptr)); -#endif - - png_write_complete_chunk(png_ptr, png_IDAT, data, size); - png_ptr->zstream.avail_out = 0; - png_ptr->zstream.next_out = NULL; - png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT; - - png_ptr->zowner = 0; /* Release the stream */ - return; - } - - else - { - /* This is an error condition. */ - png_zstream_error(png_ptr, ret); - png_error(png_ptr, png_ptr->zstream.msg); - } - } -} - -/* Write an IEND chunk */ -void /* PRIVATE */ -png_write_IEND(png_structrp png_ptr) -{ - png_debug(1, "in png_write_IEND"); - - png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); - png_ptr->mode |= PNG_HAVE_IEND; -} - -#ifdef PNG_WRITE_gAMA_SUPPORTED -/* Write a gAMA chunk */ -void /* PRIVATE */ -png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma) -{ - png_byte buf[4]; - - png_debug(1, "in png_write_gAMA"); - - /* file_gamma is saved in 1/100,000ths */ - png_save_uint_32(buf, (png_uint_32)file_gamma); - png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); -} -#endif - -#ifdef PNG_WRITE_sRGB_SUPPORTED -/* Write a sRGB chunk */ -void /* PRIVATE */ -png_write_sRGB(png_structrp png_ptr, int srgb_intent) -{ - png_byte buf[1]; - - png_debug(1, "in png_write_sRGB"); - - if (srgb_intent >= PNG_sRGB_INTENT_LAST) - png_warning(png_ptr, - "Invalid sRGB rendering intent specified"); - - buf[0]=(png_byte)srgb_intent; - png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); -} -#endif - -#ifdef PNG_WRITE_iCCP_SUPPORTED -/* Write an iCCP chunk */ -void /* PRIVATE */ -png_write_iCCP(png_structrp png_ptr, png_const_charp name, - png_const_bytep profile) -{ - png_uint_32 name_len; - png_uint_32 profile_len; - png_byte new_name[81]; /* 1 byte for the compression byte */ - compression_state comp; - png_uint_32 temp; - - png_debug(1, "in png_write_iCCP"); - - /* These are all internal problems: the profile should have been checked - * before when it was stored. - */ - if (profile == NULL) - png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */ - - profile_len = png_get_uint_32(profile); - - if (profile_len < 132) - png_error(png_ptr, "ICC profile too short"); - - temp = (png_uint_32) (*(profile+8)); - if (temp > 3 && (profile_len & 0x03)) - png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)"); - - { - png_uint_32 embedded_profile_len = png_get_uint_32(profile); - - if (profile_len != embedded_profile_len) - png_error(png_ptr, "Profile length does not match profile"); - } - - name_len = png_check_keyword(png_ptr, name, new_name); - - if (name_len == 0) - png_error(png_ptr, "iCCP: invalid keyword"); - - new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE; - - /* Make sure we include the NULL after the name and the compression type */ - ++name_len; - - png_text_compress_init(&comp, profile, profile_len); - - /* Allow for keyword terminator and compression byte */ - if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - - png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len); - - png_write_chunk_data(png_ptr, new_name, name_len); - - png_write_compressed_data_out(png_ptr, &comp); - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_sPLT_SUPPORTED -/* Write a sPLT chunk */ -void /* PRIVATE */ -png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette) -{ - png_uint_32 name_len; - png_byte new_name[80]; - png_byte entrybuf[10]; - png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); - png_size_t palette_size = entry_size * spalette->nentries; - png_sPLT_entryp ep; -#ifndef PNG_POINTER_INDEXING_SUPPORTED - int i; -#endif - - png_debug(1, "in png_write_sPLT"); - - name_len = png_check_keyword(png_ptr, spalette->name, new_name); - - if (name_len == 0) - png_error(png_ptr, "sPLT: invalid keyword"); - - /* Make sure we include the NULL after the name */ - png_write_chunk_header(png_ptr, png_sPLT, - (png_uint_32)(name_len + 2 + palette_size)); - - png_write_chunk_data(png_ptr, (png_bytep)new_name, - (png_size_t)(name_len + 1)); - - png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1); - - /* Loop through each palette entry, writing appropriately */ -#ifdef PNG_POINTER_INDEXING_SUPPORTED - for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++) - { - if (spalette->depth == 8) - { - entrybuf[0] = (png_byte)ep->red; - entrybuf[1] = (png_byte)ep->green; - entrybuf[2] = (png_byte)ep->blue; - entrybuf[3] = (png_byte)ep->alpha; - png_save_uint_16(entrybuf + 4, ep->frequency); - } - - else - { - png_save_uint_16(entrybuf + 0, ep->red); - png_save_uint_16(entrybuf + 2, ep->green); - png_save_uint_16(entrybuf + 4, ep->blue); - png_save_uint_16(entrybuf + 6, ep->alpha); - png_save_uint_16(entrybuf + 8, ep->frequency); - } - - png_write_chunk_data(png_ptr, entrybuf, entry_size); - } -#else - ep=spalette->entries; - for (i = 0; i>spalette->nentries; i++) - { - if (spalette->depth == 8) - { - entrybuf[0] = (png_byte)ep[i].red; - entrybuf[1] = (png_byte)ep[i].green; - entrybuf[2] = (png_byte)ep[i].blue; - entrybuf[3] = (png_byte)ep[i].alpha; - png_save_uint_16(entrybuf + 4, ep[i].frequency); - } - - else - { - png_save_uint_16(entrybuf + 0, ep[i].red); - png_save_uint_16(entrybuf + 2, ep[i].green); - png_save_uint_16(entrybuf + 4, ep[i].blue); - png_save_uint_16(entrybuf + 6, ep[i].alpha); - png_save_uint_16(entrybuf + 8, ep[i].frequency); - } - - png_write_chunk_data(png_ptr, entrybuf, entry_size); - } -#endif - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_sBIT_SUPPORTED -/* Write the sBIT chunk */ -void /* PRIVATE */ -png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type) -{ - png_byte buf[4]; - png_size_t size; - - png_debug(1, "in png_write_sBIT"); - - /* Make sure we don't depend upon the order of PNG_COLOR_8 */ - if ((color_type & PNG_COLOR_MASK_COLOR) != 0) - { - png_byte maxbits; - - maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : - png_ptr->usr_bit_depth); - - if (sbit->red == 0 || sbit->red > maxbits || - sbit->green == 0 || sbit->green > maxbits || - sbit->blue == 0 || sbit->blue > maxbits) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[0] = sbit->red; - buf[1] = sbit->green; - buf[2] = sbit->blue; - size = 3; - } - - else - { - if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[0] = sbit->gray; - size = 1; - } - - if ((color_type & PNG_COLOR_MASK_ALPHA) != 0) - { - if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[size++] = sbit->alpha; - } - - png_write_complete_chunk(png_ptr, png_sBIT, buf, size); -} -#endif - -#ifdef PNG_WRITE_cHRM_SUPPORTED -/* Write the cHRM chunk */ -void /* PRIVATE */ -png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy) -{ - png_byte buf[32]; - - png_debug(1, "in png_write_cHRM"); - - /* Each value is saved in 1/100,000ths */ - png_save_int_32(buf, xy->whitex); - png_save_int_32(buf + 4, xy->whitey); - - png_save_int_32(buf + 8, xy->redx); - png_save_int_32(buf + 12, xy->redy); - - png_save_int_32(buf + 16, xy->greenx); - png_save_int_32(buf + 20, xy->greeny); - - png_save_int_32(buf + 24, xy->bluex); - png_save_int_32(buf + 28, xy->bluey); - - png_write_complete_chunk(png_ptr, png_cHRM, buf, 32); -} -#endif - -#ifdef PNG_WRITE_tRNS_SUPPORTED -/* Write the tRNS chunk */ -void /* PRIVATE */ -png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha, - png_const_color_16p tran, int num_trans, int color_type) -{ - png_byte buf[6]; - - png_debug(1, "in png_write_tRNS"); - - if (color_type == PNG_COLOR_TYPE_PALETTE) - { - if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) - { - png_app_warning(png_ptr, - "Invalid number of transparent colors specified"); - return; - } - - /* Write the chunk out as it is */ - png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, - (png_size_t)num_trans); - } - - else if (color_type == PNG_COLOR_TYPE_GRAY) - { - /* One 16-bit value */ - if (tran->gray >= (1 << png_ptr->bit_depth)) - { - png_app_warning(png_ptr, - "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); - - return; - } - - png_save_uint_16(buf, tran->gray); - png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); - } - - else if (color_type == PNG_COLOR_TYPE_RGB) - { - /* Three 16-bit values */ - png_save_uint_16(buf, tran->red); - png_save_uint_16(buf + 2, tran->green); - png_save_uint_16(buf + 4, tran->blue); -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0) -#else - if ((buf[0] | buf[2] | buf[4]) != 0) -#endif - { - png_app_warning(png_ptr, - "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); - return; - } - - png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); - } - - else - { - png_app_warning(png_ptr, "Can't write tRNS with an alpha channel"); - } -} -#endif - -#ifdef PNG_WRITE_bKGD_SUPPORTED -/* Write the background chunk */ -void /* PRIVATE */ -png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type) -{ - png_byte buf[6]; - - png_debug(1, "in png_write_bKGD"); - - if (color_type == PNG_COLOR_TYPE_PALETTE) - { - if ( -#ifdef PNG_MNG_FEATURES_SUPPORTED - (png_ptr->num_palette != 0 || - (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) && -#endif - back->index >= png_ptr->num_palette) - { - png_warning(png_ptr, "Invalid background palette index"); - return; - } - - buf[0] = back->index; - png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); - } - - else if ((color_type & PNG_COLOR_MASK_COLOR) != 0) - { - png_save_uint_16(buf, back->red); - png_save_uint_16(buf + 2, back->green); - png_save_uint_16(buf + 4, back->blue); -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0) -#else - if ((buf[0] | buf[2] | buf[4]) != 0) -#endif - { - png_warning(png_ptr, - "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); - - return; - } - - png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); - } - - else - { - if (back->gray >= (1 << png_ptr->bit_depth)) - { - png_warning(png_ptr, - "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); - - return; - } - - png_save_uint_16(buf, back->gray); - png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); - } -} -#endif - -#ifdef PNG_WRITE_hIST_SUPPORTED -/* Write the histogram */ -void /* PRIVATE */ -png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist) -{ - int i; - png_byte buf[3]; - - png_debug(1, "in png_write_hIST"); - - if (num_hist > (int)png_ptr->num_palette) - { - png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, - png_ptr->num_palette); - - png_warning(png_ptr, "Invalid number of histogram entries specified"); - return; - } - - png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); - - for (i = 0; i < num_hist; i++) - { - png_save_uint_16(buf, hist[i]); - png_write_chunk_data(png_ptr, buf, (png_size_t)2); - } - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_tEXt_SUPPORTED -/* Write a tEXt chunk */ -void /* PRIVATE */ -png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, - png_size_t text_len) -{ - png_uint_32 key_len; - png_byte new_key[80]; - - png_debug(1, "in png_write_tEXt"); - - key_len = png_check_keyword(png_ptr, key, new_key); - - if (key_len == 0) - png_error(png_ptr, "tEXt: invalid keyword"); - - if (text == NULL || *text == '\0') - text_len = 0; - - else - text_len = strlen(text); - - if (text_len > PNG_UINT_31_MAX - (key_len+1)) - png_error(png_ptr, "tEXt: text too long"); - - /* Make sure we include the 0 after the key */ - png_write_chunk_header(png_ptr, png_tEXt, - (png_uint_32)/*checked above*/(key_len + text_len + 1)); - /* - * We leave it to the application to meet PNG-1.0 requirements on the - * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of - * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. - * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. - */ - png_write_chunk_data(png_ptr, new_key, key_len + 1); - - if (text_len != 0) - png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len); - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_zTXt_SUPPORTED -/* Write a compressed text chunk */ -void /* PRIVATE */ -png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, - int compression) -{ - png_uint_32 key_len; - png_byte new_key[81]; - compression_state comp; - - png_debug(1, "in png_write_zTXt"); - - if (compression == PNG_TEXT_COMPRESSION_NONE) - { - png_write_tEXt(png_ptr, key, text, 0); - return; - } - - if (compression != PNG_TEXT_COMPRESSION_zTXt) - png_error(png_ptr, "zTXt: invalid compression type"); - - key_len = png_check_keyword(png_ptr, key, new_key); - - if (key_len == 0) - png_error(png_ptr, "zTXt: invalid keyword"); - - /* Add the compression method and 1 for the keyword separator. */ - new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; - ++key_len; - - /* Compute the compressed data; do it now for the length */ - png_text_compress_init(&comp, (png_const_bytep)text, - text == NULL ? 0 : strlen(text)); - - if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - - /* Write start of chunk */ - png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len); - - /* Write key */ - png_write_chunk_data(png_ptr, new_key, key_len); - - /* Write the compressed data */ - png_write_compressed_data_out(png_ptr, &comp); - - /* Close the chunk */ - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_iTXt_SUPPORTED -/* Write an iTXt chunk */ -void /* PRIVATE */ -png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key, - png_const_charp lang, png_const_charp lang_key, png_const_charp text) -{ - png_uint_32 key_len, prefix_len; - png_size_t lang_len, lang_key_len; - png_byte new_key[82]; - compression_state comp; - - png_debug(1, "in png_write_iTXt"); - - key_len = png_check_keyword(png_ptr, key, new_key); - - if (key_len == 0) - png_error(png_ptr, "iTXt: invalid keyword"); - - /* Set the compression flag */ - switch (compression) - { - case PNG_ITXT_COMPRESSION_NONE: - case PNG_TEXT_COMPRESSION_NONE: - compression = new_key[++key_len] = 0; /* no compression */ - break; - - case PNG_TEXT_COMPRESSION_zTXt: - case PNG_ITXT_COMPRESSION_zTXt: - compression = new_key[++key_len] = 1; /* compressed */ - break; - - default: - png_error(png_ptr, "iTXt: invalid compression"); - } - - new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; - ++key_len; /* for the keywod separator */ - - /* We leave it to the application to meet PNG-1.0 requirements on the - * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of - * any non-Latin-1 characters except for NEWLINE. ISO PNG, however, - * specifies that the text is UTF-8 and this really doesn't require any - * checking. - * - * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. - * - * TODO: validate the language tag correctly (see the spec.) - */ - if (lang == NULL) lang = ""; /* empty language is valid */ - lang_len = strlen(lang)+1; - if (lang_key == NULL) lang_key = ""; /* may be empty */ - lang_key_len = strlen(lang_key)+1; - if (text == NULL) text = ""; /* may be empty */ - - prefix_len = key_len; - if (lang_len > PNG_UINT_31_MAX-prefix_len) - prefix_len = PNG_UINT_31_MAX; - else - prefix_len = (png_uint_32)(prefix_len + lang_len); - - if (lang_key_len > PNG_UINT_31_MAX-prefix_len) - prefix_len = PNG_UINT_31_MAX; - else - prefix_len = (png_uint_32)(prefix_len + lang_key_len); - - png_text_compress_init(&comp, (png_const_bytep)text, strlen(text)); - - if (compression != 0) - { - if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - } - - else - { - if (comp.input_len > PNG_UINT_31_MAX-prefix_len) - png_error(png_ptr, "iTXt: uncompressed text too long"); - - /* So the string will fit in a chunk: */ - comp.output_len = (png_uint_32)/*SAFE*/comp.input_len; - } - - png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len); - - png_write_chunk_data(png_ptr, new_key, key_len); - - png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len); - - png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len); - - if (compression != 0) - png_write_compressed_data_out(png_ptr, &comp); - - else - png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len); - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_oFFs_SUPPORTED -/* Write the oFFs chunk */ -void /* PRIVATE */ -png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset, - int unit_type) -{ - png_byte buf[9]; - - png_debug(1, "in png_write_oFFs"); - - if (unit_type >= PNG_OFFSET_LAST) - png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); - - png_save_int_32(buf, x_offset); - png_save_int_32(buf + 4, y_offset); - buf[8] = (png_byte)unit_type; - - png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); -} -#endif -#ifdef PNG_WRITE_pCAL_SUPPORTED -/* Write the pCAL chunk (described in the PNG extensions document) */ -void /* PRIVATE */ -png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0, - png_int_32 X1, int type, int nparams, png_const_charp units, - png_charpp params) -{ - png_uint_32 purpose_len; - png_size_t units_len, total_len; - png_size_tp params_len; - png_byte buf[10]; - png_byte new_purpose[80]; - int i; - - png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); - - if (type >= PNG_EQUATION_LAST) - png_error(png_ptr, "Unrecognized equation type for pCAL chunk"); - - purpose_len = png_check_keyword(png_ptr, purpose, new_purpose); - - if (purpose_len == 0) - png_error(png_ptr, "pCAL: invalid keyword"); - - ++purpose_len; /* terminator */ - - png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); - units_len = strlen(units) + (nparams == 0 ? 0 : 1); - png_debug1(3, "pCAL units length = %d", (int)units_len); - total_len = purpose_len + units_len + 10; - - params_len = (png_size_tp)png_malloc(png_ptr, - (png_alloc_size_t)(nparams * (sizeof (png_size_t)))); - - /* Find the length of each parameter, making sure we don't count the - * null terminator for the last parameter. - */ - for (i = 0; i < nparams; i++) - { - params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1); - png_debug2(3, "pCAL parameter %d length = %lu", i, - (unsigned long)params_len[i]); - total_len += params_len[i]; - } - - png_debug1(3, "pCAL total length = %d", (int)total_len); - png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len); - png_write_chunk_data(png_ptr, new_purpose, purpose_len); - png_save_int_32(buf, X0); - png_save_int_32(buf + 4, X1); - buf[8] = (png_byte)type; - buf[9] = (png_byte)nparams; - png_write_chunk_data(png_ptr, buf, (png_size_t)10); - png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); - - for (i = 0; i < nparams; i++) - { - png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]); - } - - png_free(png_ptr, params_len); - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_sCAL_SUPPORTED -/* Write the sCAL chunk */ -void /* PRIVATE */ -png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width, - png_const_charp height) -{ - png_byte buf[64]; - png_size_t wlen, hlen, total_len; - - png_debug(1, "in png_write_sCAL_s"); - - wlen = strlen(width); - hlen = strlen(height); - total_len = wlen + hlen + 2; - - if (total_len > 64) - { - png_warning(png_ptr, "Can't write sCAL (buffer too small)"); - return; - } - - buf[0] = (png_byte)unit; - memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ - memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ - - png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); - png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len); -} -#endif - -#ifdef PNG_WRITE_pHYs_SUPPORTED -/* Write the pHYs chunk */ -void /* PRIVATE */ -png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit, - png_uint_32 y_pixels_per_unit, - int unit_type) -{ - png_byte buf[9]; - - png_debug(1, "in png_write_pHYs"); - - if (unit_type >= PNG_RESOLUTION_LAST) - png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); - - png_save_uint_32(buf, x_pixels_per_unit); - png_save_uint_32(buf + 4, y_pixels_per_unit); - buf[8] = (png_byte)unit_type; - - png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); -} -#endif - -#ifdef PNG_WRITE_tIME_SUPPORTED -/* Write the tIME chunk. Use either png_convert_from_struct_tm() - * or png_convert_from_time_t(), or fill in the structure yourself. - */ -void /* PRIVATE */ -png_write_tIME(png_structrp png_ptr, png_const_timep mod_time) -{ - png_byte buf[7]; - - png_debug(1, "in png_write_tIME"); - - if (mod_time->month > 12 || mod_time->month < 1 || - mod_time->day > 31 || mod_time->day < 1 || - mod_time->hour > 23 || mod_time->second > 60) - { - png_warning(png_ptr, "Invalid time specified for tIME chunk"); - return; - } - - png_save_uint_16(buf, mod_time->year); - buf[2] = mod_time->month; - buf[3] = mod_time->day; - buf[4] = mod_time->hour; - buf[5] = mod_time->minute; - buf[6] = mod_time->second; - - png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7); -} -#endif - -/* Initializes the row writing capability of libpng */ -void /* PRIVATE */ -png_write_start_row(png_structrp png_ptr) -{ -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; -#endif - - png_alloc_size_t buf_size; - int usr_pixel_depth; - -#ifdef PNG_WRITE_FILTER_SUPPORTED - png_byte filters; -#endif - - png_debug(1, "in png_write_start_row"); - - usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; - buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1; - - /* 1.5.6: added to allow checking in the row write code. */ - png_ptr->transformed_pixel_depth = png_ptr->pixel_depth; - png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth; - - /* Set up row buffer */ - png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); - - png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; - -#ifdef PNG_WRITE_FILTER_SUPPORTED - filters = png_ptr->do_filter; - - if (png_ptr->height == 1) - filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); - - if (png_ptr->width == 1) - filters &= 0xff & ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); - - if (filters == 0) - filters = PNG_FILTER_NONE; - - png_ptr->do_filter = filters; - - if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG | - PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL) - { - int num_filters = 0; - - png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); - - if (filters & PNG_FILTER_SUB) - num_filters++; - - if (filters & PNG_FILTER_UP) - num_filters++; - - if (filters & PNG_FILTER_AVG) - num_filters++; - - if (filters & PNG_FILTER_PAETH) - num_filters++; - - if (num_filters > 1) - png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr, - buf_size)); - } - - /* We only need to keep the previous row if we are using one of the following - * filters. - */ - if ((filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) != 0) - png_ptr->prev_row = png_voidcast(png_bytep, - png_calloc(png_ptr, buf_size)); -#endif /* WRITE_FILTER */ - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* If interlaced, we need to set up width and height of pass */ - if (png_ptr->interlaced != 0) - { - if ((png_ptr->transformations & PNG_INTERLACE) == 0) - { - png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - - png_pass_ystart[0]) / png_pass_yinc[0]; - - png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - - png_pass_start[0]) / png_pass_inc[0]; - } - - else - { - png_ptr->num_rows = png_ptr->height; - png_ptr->usr_width = png_ptr->width; - } - } - - else -#endif - { - png_ptr->num_rows = png_ptr->height; - png_ptr->usr_width = png_ptr->width; - } -} - -/* Internal use only. Called when finished processing a row of data. */ -void /* PRIVATE */ -png_write_finish_row(png_structrp png_ptr) -{ -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; -#endif - - png_debug(1, "in png_write_finish_row"); - - /* Next row */ - png_ptr->row_number++; - - /* See if we are done */ - if (png_ptr->row_number < png_ptr->num_rows) - return; - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* If interlaced, go to next pass */ - if (png_ptr->interlaced != 0) - { - png_ptr->row_number = 0; - if ((png_ptr->transformations & PNG_INTERLACE) != 0) - { - png_ptr->pass++; - } - - else - { - /* Loop until we find a non-zero width or height pass */ - do - { - png_ptr->pass++; - - if (png_ptr->pass >= 7) - break; - - png_ptr->usr_width = (png_ptr->width + - png_pass_inc[png_ptr->pass] - 1 - - png_pass_start[png_ptr->pass]) / - png_pass_inc[png_ptr->pass]; - - png_ptr->num_rows = (png_ptr->height + - png_pass_yinc[png_ptr->pass] - 1 - - png_pass_ystart[png_ptr->pass]) / - png_pass_yinc[png_ptr->pass]; - - if ((png_ptr->transformations & PNG_INTERLACE) != 0) - break; - - } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); - - } - - /* Reset the row above the image for the next pass */ - if (png_ptr->pass < 7) - { - if (png_ptr->prev_row != NULL) - memset(png_ptr->prev_row, 0, - (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* - png_ptr->usr_bit_depth, png_ptr->width)) + 1); - - return; - } - } -#endif - - /* If we get here, we've just written the last row, so we need - to flush the compressor */ - png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH); -} - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED -/* Pick out the correct pixels for the interlace pass. - * The basic idea here is to go through the row with a source - * pointer and a destination pointer (sp and dp), and copy the - * correct pixels for the pass. As the row gets compacted, - * sp will always be >= dp, so we should never overwrite anything. - * See the default: case for the easiest code to understand. - */ -void /* PRIVATE */ -png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) -{ - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - png_debug(1, "in png_do_write_interlace"); - - /* We don't have to do anything on the last pass (6) */ - if (pass < 6) - { - /* Each pixel depth is handled separately */ - switch (row_info->pixel_depth) - { - case 1: - { - png_bytep sp; - png_bytep dp; - unsigned int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - d = 0; - shift = 7; - - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 3); - value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; - d |= (value << shift); - - if (shift == 0) - { - shift = 7; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift--; - - } - if (shift != 7) - *dp = (png_byte)d; - - break; - } - - case 2: - { - png_bytep sp; - png_bytep dp; - unsigned int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - shift = 6; - d = 0; - - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 2); - value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; - d |= (value << shift); - - if (shift == 0) - { - shift = 6; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift -= 2; - } - if (shift != 6) - *dp = (png_byte)d; - - break; - } - - case 4: - { - png_bytep sp; - png_bytep dp; - unsigned int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - shift = 4; - d = 0; - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 1); - value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; - d |= (value << shift); - - if (shift == 0) - { - shift = 4; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift -= 4; - } - if (shift != 4) - *dp = (png_byte)d; - - break; - } - - default: - { - png_bytep sp; - png_bytep dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - png_size_t pixel_bytes; - - /* Start at the beginning */ - dp = row; - - /* Find out how many bytes each pixel takes up */ - pixel_bytes = (row_info->pixel_depth >> 3); - - /* Loop through the row, only looking at the pixels that matter */ - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - /* Find out where the original pixel is */ - sp = row + (png_size_t)i * pixel_bytes; - - /* Move the pixel */ - if (dp != sp) - memcpy(dp, sp, pixel_bytes); - - /* Next pixel */ - dp += pixel_bytes; - } - break; - } - } - /* Set new row width */ - row_info->width = (row_info->width + - png_pass_inc[pass] - 1 - - png_pass_start[pass]) / - png_pass_inc[pass]; - - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, - row_info->width); - } -} -#endif - - -/* This filters the row, chooses which filter to use, if it has not already - * been specified by the application, and then writes the row out with the - * chosen filter. - */ -static void /* PRIVATE */ -png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row, - png_size_t row_bytes); - -#ifdef PNG_WRITE_FILTER_SUPPORTED -static png_size_t /* PRIVATE */ -png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp, - const png_size_t row_bytes, const png_size_t lmins) -{ - png_bytep rp, dp, lp; - png_size_t i; - png_size_t sum = 0; - int v; - - png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB; - - for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp; - i++, rp++, dp++) - { - v = *dp = *rp; - sum += (v < 128) ? v : 256 - v; - } - - for (lp = png_ptr->row_buf + 1; i < row_bytes; - i++, rp++, lp++, dp++) - { - v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - - return (sum); -} - -static png_size_t /* PRIVATE */ -png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes, - const png_size_t lmins) -{ - png_bytep rp, dp, pp; - png_size_t i; - png_size_t sum = 0; - int v; - - png_ptr->try_row[0] = PNG_FILTER_VALUE_UP; - - for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, - pp = png_ptr->prev_row + 1; i < row_bytes; - i++, rp++, pp++, dp++) - { - v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - - return (sum); -} - -static png_size_t /* PRIVATE */ -png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp, - const png_size_t row_bytes, const png_size_t lmins) -{ - png_bytep rp, dp, pp, lp; - png_uint_32 i; - png_size_t sum = 0; - int v; - - png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG; - - for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, - pp = png_ptr->prev_row + 1; i < bpp; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); - - sum += (v < 128) ? v : 256 - v; - } - - for (lp = png_ptr->row_buf + 1; i < row_bytes; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) - & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - - return (sum); -} - -static png_size_t /* PRIVATE */ -png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp, - const png_size_t row_bytes, const png_size_t lmins) -{ - png_bytep rp, dp, pp, cp, lp; - png_size_t i; - png_size_t sum = 0; - int v; - - png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH; - - for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, - pp = png_ptr->prev_row + 1; i < bpp; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); - - sum += (v < 128) ? v : 256 - v; - } - - for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes; - i++) - { - int a, b, c, pa, pb, pc, p; - - b = *pp++; - c = *cp++; - a = *lp++; - - p = b - c; - pc = a - c; - -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif - - p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; - - v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - - return (sum); -} -#endif /* WRITE_FILTER */ - -void /* PRIVATE */ -png_write_find_filter(png_structrp png_ptr, png_row_infop row_info) -{ -#ifndef PNG_WRITE_FILTER_SUPPORTED - png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1); -#else - png_byte filter_to_do = png_ptr->do_filter; - png_bytep row_buf; - png_bytep best_row; - png_uint_32 bpp; - png_size_t mins; - png_size_t row_bytes = row_info->rowbytes; - - png_debug(1, "in png_write_find_filter"); - - /* Find out how many bytes offset each pixel is */ - bpp = (row_info->pixel_depth + 7) >> 3; - - row_buf = png_ptr->row_buf; - mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the - running sum */; - - /* The prediction method we use is to find which method provides the - * smallest value when summing the absolute values of the distances - * from zero, using anything >= 128 as negative numbers. This is known - * as the "minimum sum of absolute differences" heuristic. Other - * heuristics are the "weighted minimum sum of absolute differences" - * (experimental and can in theory improve compression), and the "zlib - * predictive" method (not implemented yet), which does test compressions - * of lines using different filter methods, and then chooses the - * (series of) filter(s) that give minimum compressed data size (VERY - * computationally expensive). - * - * GRR 980525: consider also - * - * (1) minimum sum of absolute differences from running average (i.e., - * keep running sum of non-absolute differences & count of bytes) - * [track dispersion, too? restart average if dispersion too large?] - * - * (1b) minimum sum of absolute differences from sliding average, probably - * with window size <= deflate window (usually 32K) - * - * (2) minimum sum of squared differences from zero or running average - * (i.e., ~ root-mean-square approach) - */ - - - /* We don't need to test the 'no filter' case if this is the only filter - * that has been chosen, as it doesn't actually do anything to the data. - */ - best_row = png_ptr->row_buf; - - - if ((filter_to_do & PNG_FILTER_NONE) != 0 && filter_to_do != PNG_FILTER_NONE) - { - png_bytep rp; - png_size_t sum = 0; - png_size_t i; - int v; - - if (PNG_SIZE_MAX/128 <= row_bytes) - { - for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) - { - /* Check for overflow */ - if (sum > PNG_SIZE_MAX/128 - 256) - break; - - v = *rp; - sum += (v < 128) ? v : 256 - v; - } - } - else /* Overflow is not possible */ - { - for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) - { - v = *rp; - sum += (v < 128) ? v : 256 - v; - } - } - - mins = sum; - } - - /* Sub filter */ - if (filter_to_do == PNG_FILTER_SUB) - /* It's the only filter so no testing is needed */ - { - (void) png_setup_sub_row(png_ptr, bpp, row_bytes, mins); - best_row = png_ptr->try_row; - } - - else if ((filter_to_do & PNG_FILTER_SUB) != 0) - { - png_size_t sum; - png_size_t lmins = mins; - - sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins); - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->try_row; - if (png_ptr->tst_row != NULL) - { - png_ptr->try_row = png_ptr->tst_row; - png_ptr->tst_row = best_row; - } - } - } - - /* Up filter */ - if (filter_to_do == PNG_FILTER_UP) - { - (void) png_setup_up_row(png_ptr, row_bytes, mins); - best_row = png_ptr->try_row; - } - - else if ((filter_to_do & PNG_FILTER_UP) != 0) - { - png_size_t sum; - png_size_t lmins = mins; - - sum = png_setup_up_row(png_ptr, row_bytes, lmins); - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->try_row; - if (png_ptr->tst_row != NULL) - { - png_ptr->try_row = png_ptr->tst_row; - png_ptr->tst_row = best_row; - } - } - } - - /* Avg filter */ - if (filter_to_do == PNG_FILTER_AVG) - { - (void) png_setup_avg_row(png_ptr, bpp, row_bytes, mins); - best_row = png_ptr->try_row; - } - - else if ((filter_to_do & PNG_FILTER_AVG) != 0) - { - png_size_t sum; - png_size_t lmins = mins; - - sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins); - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->try_row; - if (png_ptr->tst_row != NULL) - { - png_ptr->try_row = png_ptr->tst_row; - png_ptr->tst_row = best_row; - } - } - } - - /* Paeth filter */ - if ((filter_to_do == PNG_FILTER_PAETH) != 0) - { - (void) png_setup_paeth_row(png_ptr, bpp, row_bytes, mins); - best_row = png_ptr->try_row; - } - - else if ((filter_to_do & PNG_FILTER_PAETH) != 0) - { - png_size_t sum; - png_size_t lmins = mins; - - sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins); - - if (sum < mins) - { - best_row = png_ptr->try_row; - if (png_ptr->tst_row != NULL) - { - png_ptr->try_row = png_ptr->tst_row; - png_ptr->tst_row = best_row; - } - } - } - - /* Do the actual writing of the filtered row data from the chosen filter. */ - png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1); - -#endif /* WRITE_FILTER */ -} - - -/* Do the actual writing of a previously filtered row. */ -static void -png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row, - png_size_t full_row_length/*includes filter byte*/) -{ - png_debug(1, "in png_write_filtered_row"); - - png_debug1(2, "filter = %d", filtered_row[0]); - - png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH); - -#ifdef PNG_WRITE_FILTER_SUPPORTED - /* Swap the current and previous rows */ - if (png_ptr->prev_row != NULL) - { - png_bytep tptr; - - tptr = png_ptr->prev_row; - png_ptr->prev_row = png_ptr->row_buf; - png_ptr->row_buf = tptr; - } -#endif /* WRITE_FILTER */ - - /* Finish row - updates counters and flushes zlib if last row */ - png_write_finish_row(png_ptr); - -#ifdef PNG_WRITE_FLUSH_SUPPORTED - png_ptr->flush_rows++; - - if (png_ptr->flush_dist > 0 && - png_ptr->flush_rows >= png_ptr->flush_dist) - { - png_write_flush(png_ptr); - } -#endif /* WRITE_FLUSH */ -} -#endif /* WRITE */ |