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diff --git a/dumb/dumb-kode54/docs/dumb.txt b/dumb/dumb-kode54/docs/dumb.txt deleted file mode 100644 index 4f6cc69b..00000000 --- a/dumb/dumb-kode54/docs/dumb.txt +++ /dev/null @@ -1,1699 +0,0 @@ -/* _______ ____ __ ___ ___
- * \ _ \ \ / \ / \ \ / / ' ' '
- * | | \ \ | | || | \/ | . .
- * | | | | | | || ||\ /| |
- * | | | | | | || || \/ | | ' ' '
- * | | | | | | || || | | . .
- * | |_/ / \ \__// || | |
- * /_______/ynamic \____/niversal /__\ /____\usic /| . . ibliotheque
- * / \
- * / . \
- * dumb.txt - DUMB library reference. / / \ \
- * | < / \_
- * See readme.txt for general information on | \/ /\ /
- * DUMB and how to set it up. \_ / > /
- * | \ / /
- * If you are new to DUMB, see howto.txt. | ' /
- * \__/
- */
-
-
-***********************************
-*** Include Files and Libraries ***
-***********************************
-
-
-dumb.h
-
- Include this if you only want the core DUMB library functions. You will
- be able to load music files and render them into memory buffers at your
- own pace. The core library is completely portable, and as such does not
- access hardware; you must relay the sound data to the sound card yourself.
- A stdio file input module is available, but you must actively register it
- if you wish to use it (see dumb_register_stdfiles()); if you do not
- register it, it will not be linked into your executable. You must register
- it, or a DUMBFILE module of your own, in order to load stand-alone music
- files.
-
- Optimised: -ldumb or /link dumb.lib
- Debugging: -ldumbd or /link dumbd.lib
-
-
-aldumb.h
-
- Include this if you wish to use DUMB with Allegro. This will provide you
- with functions to play DUHs back through Allegro's audio streams and embed
- music files in Allegro datafiles. A file input module using Allegro's
- packfiles is provided; you have a choice between this and the stdio
- module (or provide one of your own). You will be able to load datafiles
- containing music files no matter which file input module you register, or
- even if you register no file input module. However, you must register a
- file input module in order to load stand-alone files.
-
- Optimised: -laldmb -ldumb -lalleg or /link aldmb.lib alleg.lib dumb.lib
- Debugging: -laldmd -ldumbd -lalld or /link aldmd.lib alld.lib dumbd.lib
-
- aldmb or aldmd must be linked in first, so the symbols can be resolved
- when linking in the other two libraries.
-
-
-***************************
-*** Version Information ***
-***************************
-
-
-#define DUMB_MAJOR_VERSION
-#define DUMB_MINOR_VERSION
-#define DUMB_REVISION_VERSION
-
- Numeric constants representing this version of DUMB. If this were version
- 1.0, DUMB_MAJOR_VERSION would be 1 and DUMB_MINOR_VERSION would be 0.
- DUMB_REVISION_VERSION will be 0 on any significant releases, and will be
- incremented as releases with bugfixes and minor features are made.
-
- Typical usage:
-
- #if DUMB_MAJOR_VERSION < 1
- #error This add-on requires DUMB v1.0 or higher. Please upgrade.
- #endif
-
-
-#define DUMB_VERSION
-
- A numeric constant which appears in the format MMmmrr when displayed in
- decimal (M for major, m for minor, r for revision). This is most useful
- for comparing version numbers; it has little other practical use.
-
- Typical usage:
-
- #if DUMB_VERSION < 801
- #error This game requires DUMB v0.8.1 or higher. Please upgrade.
- #endif
-
- #if DUMB_VERSION < 10002
- #error This game requires DUMB v1.0.2 or higher. Please upgrade.
- #endif
-
-
-#define DUMB_VERSION_STR
-
- String constant representing this version of DUMB. If this were Version
- 1.0, DUMB_VERSION_STR would be "1.0". DUMB_REVISION_VERSION will only
- appear on the end if it is nonzero; then DUMB_VERSION_STR might be
- "1.0.1".
-
-
-#define DUMB_NAME
-
- A string identifying DUMB and its version. If this were Version 1.0,
- DUMB_NAME might be "DUMB v1.0". This constant is suitable for use in your
- Credits screen if you wish to acknowledge the use of DUMB there.
-
-
-#define DUMB_YEAR
-#define DUMB_MONTH
-#define DUMB_DAY
-
- Numeric constants representing the year, month and day of this release of
- DUMB. All four digits are included in the year. Please note that
- DUMB_MONTH and DUMB_DAY were inadvertently swapped in the v0.8 release.
-
-
-#define DUMB_YEAR_STR4
-#define DUMB_YEAR_STR2
-#define DUMB_MONTH_STR2
-#define DUMB_MONTH_STR1
-#define DUMB_DAY_STR2
-#define DUMB_DAY_STR1
-
- String constants representing the year, month and day of this release of
- DUMB. DUMB_MONTH_STR2 and DUMB_DAY_STR2 include a leading zero if the
- month or day respectively are less than ten; the STR1 variations do not.
- DUMB_YEAR_STR2 contains only the two rightmost digits of the year, while
- DUMB_YEAR_STR4 contains all four. I recommend using DUMB_YEAR_STR4,
- especially so soon after the turn of the century (indeed the millennium).
- However, it is a matter of personal preference which you use.
-
- Please note that the month and day were inadvertently swapped in the v0.8
- release.
-
-
-#define DUMB_DATE
-
- A numeric constant that appears in the form yyyymmdd when displayed in
- decimal. This is most useful for comparing release dates; it has little
- other practical use.
-
- WARNING: The month and day were inadvertently swapped in the v0.8 release.
- Please do not compare this constant against any date in 2002. In
- any case, DUMB_VERSION is probably more useful for this purpose.
-
-
-#define DUMB_DATE_STR
-
- The date as a string. The format is "d.m.yyyy", with dots used as
- separators, the day written first, four digits for the year, and no
- leading zeros on the day or month. This is my preferred format. If you
- don't like it, you can construct your own format using the other
- constants. For example, "mm/dd/yy" could be constructed as follows:
-
- DUMB_MONTH_STR2 "/" DUMB_DAY_STR2 "/" DUMB_YEAR_STR2
-
- Please note that the month and day were inadvertently swapped in the v0.8
- release.
-
-
-*************************
-*** Basic Sample Type ***
-*************************
-
-
-typedef int sample_t;
-
- DUMB works internally with 32-bit integer samples, with a 'normal range'
- from -0x800000 to 0x7FFFFF (as of DUMB v0.9.2; previously they ranged from
- -0x8000 to 0x7FFF). Any samples that exceed this range will eventually be
- clipped, and could cause integer overflow in extreme cases.
-
-
-***********************************
-*** Library Clean-up Management ***
-***********************************
-
-
-int dumb_atexit(void (*proc)(void));
-
- Registers a function to be called at the end of your program. You can
- register multiple functions to be called, and the one you register last
- will be called first. If you try to register the same function twice, the
- second attempt will have no effect.
-
- See fnptr.txt for help with function pointers.
-
- You must call dumb_exit() before exiting your program for this to work
- properly. The library itself registers functions with dumb_atexit(), so it
- is important to call dumb_exit() even if you do not use dumb_atexit()
- yourself.
-
- This function will return zero on success. It will return zero when
- trying to install the same function twice. If it fails through lack of
- memory, it will return nonzero. Generally you can ignore the return code;
- in the worst case some memory will not be freed at the end. If it is
- crucial that your function be called (e.g. to shut down some hardware or
- save critical data), then you should call your function manually at the
- end of the program instead of registering it here - or use the stdlib
- function atexit(), guaranteed under ANSI C to succeed for at least 32
- functions.
-
-
-void dumb_exit(void);
-
- You should call this before exiting your program if you have used any part
- of DUMB in the program. Some parts of DUMB will allocate memory, and this
- function will free it all up.
-
- More specifically, this function will call any functions that have been
- registered with dumb_atexit(). If a part of DUMB needs shutting down, the
- shutdown procedure will have been registered in this way.
-
- dumb_exit() will, of course, also call any functions you registered with
- dumb_atexit() yourself.
-
- After a call to dumb_exit(), the list of functions is erased. If you are
- not ready to exit your program, you can start using DUMB anew as if your
- program had just started. (Note that not everything will be reset in
- practice - dumb_resampling_quality will retain whatever you set it to, for
- example, though you should not assume it will.)
-
- If you only need to call dumb_exit() once at the end of the program, you
- can use the following to register dumb_exit() with stdlib.h atexit():
-
- #include <stdlib.h>
-
- atexit(&dumb_exit);
-
- Then dumb_exit() will be called for you when your program exits. This is
- the recommended method, since it will ensure clean-up even if your program
- aborts. You should only call dumb_exit() manually if you need to shut DUMB
- down prematurely, or if atexit() is unavailable for one reason or another.
-
-
-*****************************
-*** Sequential File Input ***
-*****************************
-
-
- DUMB provides a strictly sequential file input system which uses the
- DUMBFILE struct. "Strictly sequential" means you cannot seek backwards.
- However, the system will keep track of how many bytes you have read,
- enabling you to seek forwards. DUMBFILEs provide a convenient error
- detection system, so you do not have to check the return value from every
- function call in the way you do with the ANSI C functions.
-
- Note that DUMBFILEs cannot be used for output, nor can they be used
- portably for text files.
-
- If an error occurs when reading data from a DUMBFILE, the DUMBFILE will
- become inoperative. All subsequent activities on the DUMBFILE will return
- error codes without attempting to read from the file. The position in the
- file will also be forgotten. You can find out if this has happened at any
- stage with the dumbfile_error() function. You are still required to close
- the DUMBFILE, and the return value from dumbfile_close() will tell you if
- an error has occurred.
-
- This system allows you to input large chunks of your file, neither
- checking every return value nor wasting time accessing a file that has
- already experienced an error. However, before you allocate an amount of
- memory or read in a quantity of data depending on previous input from the
- file, you should always check that such input was valid. In particular you
- should avoid passing zero or negative numbers to malloc(), and avoid
- passing negative numbers to dumbfile_skip() and dumbfile_getnc().
-
- DUMBFILEs can be hooked. In other words, you can specify your own
- functions to do the work of reading from a file. While DUMB contains two
- modules for this purpose, it does not set them up for you automatically.
- In most cases you must register one of these modules yourself, or provide
- your own module. See register_dumbfile_system(), dumb_register_stdfiles()
- and dumb_register_packfiles().
-
-
-void register_dumbfile_system(DUMBFILE_SYSTEM *dfs);
-
- Use this function to register a set of functions for use by the DUMBFILEs
- (a DUMBFILE system). The DUMBFILE_SYSTEM struct contains the following
- fields:
-
- void *(*open)(const char *filename);
- int (*skip)(void *f, long n);
- int (*getc)(void *f);
- long (*getnc)(char *ptr, long n, void *f);
- void (*close)(void *f);
-
- See fnptr.txt for help with function pointers such as these.
-
- Your 'open' function should open the file specified and return a pointer
- to a struct representing the open file. This pointer will be passed to
- your other functions as 'f'. Your 'close' function should close the file
- and free all memory pointed to by 'f'. Note that the 'close' operation
- should never be able to fail; if you are calling a function with a return
- value, you can generally ignore it.
-
- Your 'getc' function should read one byte from the file and return its
- value in the range 0 to 255. If an error occurs, you should return -1. Do
- not worry about remembering that an error has occurred; DUMB will do that
- for you.
-
- 'skip' is for skipping parts of the file, and should skip n bytes,
- returning 0 on success or any other number on failure. 'getnc' should read
- n bytes from the file, store them at 'ptr', and return the number of bytes
- read (n on success, fewer on failure). However, these two functions are
- optional, and you should only provide them if the operations can be done
- more efficiently than with repeated calls to your 'getc' function. If this
- is not the case, specify NULL for 'skip', 'getnc' or both, and DUMB will
- use your 'getc' function to do the work.
-
- Once you have written all your functions, you need to create a
- DUMBFILE_SYSTEM struct to hold them, and pass its pointer to
- register_dumbfile_system().
-
- The DUMBFILE_SYSTEM struct must be permanent. In other words, it must be
- either global or static, and you should not modify it later. DUMB will not
- make its own copy.
-
- You will most likely create your own struct to represent the open file,
- but do not be tempted to specify that struct in the function prototypes
- and pacify the compiler warnings by casting your function pointers. There
- exist computer systems where a (void *) pointer and a (MY_STRUCT *)
- pointer are represented differently in memory, and a cast of such a
- pointer causes a tangible conversion to take place. If you cast the
- function pointers, the computer cannot know when such a conversion is
- necessary. Instead, use the following structure:
-
- int myskip(void *f, long n)
- {
- FILE *file = f;
- /* Do some stuff with 'file' */
- return something;
- }
-
- If you need examples, have a look at the two existing DUMBFILE systems in
- dumb/src/core/stdfile.c and dumb/src/allegro/packfile.c.
-
-
-DUMBFILE *dumbfile_open(const char *filename);
-
- Open the specified file for input. You must pass the DUMBFILE pointer
- whenever you wish to operate on this file. When you have finished with the
- file, you must pass it to dumbfile_close().
-
- Before you use this function, make sure you have registered a DUMBFILE
- system. See register_dumbfile_system(), dumb_register_stdfiles() and
- dumb_register_packfiles().
-
- You must check the return value from this function. If it is NULL, the
- file could not be opened, and you must not pass the DUMBFILE to any other
- function. The debugging library will abort if you get this wrong; the
- optimised library will act weird.
-
-
-DUMBFILE *dumbfile_open_ex(void *file, DUMBFILE_SYSTEM *dfs);
-
- This function is provided for more specialised use. You should create a
- DUMBFILE_SYSTEM specially for the purpose. Its 'open' field is irrelevant;
- for neatness, set it to NULL, unless you are using this DUMBFILE_SYSTEM
- with register_dumbfile_system() as well.
-
- When you have called this function, the DUMBFILE struct it returned can be
- used as normal. The specified DUMBFILE_SYSTEM will be used for all input,
- with 'file' passed to your 'skip', 'getc' and 'getnc' functions as 'f'.
- This can be used, for example, to read from an already open file.
-
- Note that the position will always be initialised to 0 for this DUMBFILE.
- This means for example that offsets in the file do not need adjusting when
- embedding data in a larger file.
-
- There are two ways to use this function. If you want 'file' to persist
- after using a DUMBFILE returned by this function, you should make sure the
- 'close' field in the DUMBFILE is set to NULL. When the DUMBFILE is closed,
- 'file' will be left alone, and you can and should deal with it yourself
- when the DUMBFILE has been closed.
-
- Alternatively, you can provide a 'close' function to get rid of 'file' for
- you when the DUMBFILE is closed. If you do this, you should not otherwise
- use 'file' after a call to this function.
-
- If dumbfile_open_ex() has to return NULL, owing to lack of memory, then
- your 'close' function will be called if provided. In other words, if you
- have provided a 'close' function, then you no longer need to worry about
- 'file' whether this function succeeds or not.
-
- See dumb/src/helpers/stdfile.c and dumb/src/allegro/packfile.c for
- examples of how to use this function. Neither provides a 'close' function,
- so I hope my explanation here will suffice. If not, please feel free to
- contact me so I can make the explanation clearer and help you do what you
- want to do. Contact details are at the end of this file.
-
-
-long dumbfile_pos(DUMBFILE *f);
-
- Returns the number of bytes read from the DUMBFILE (or skipped) since it
- was opened, or -1 if an error has occurred while reading.
-
-
-int dumbfile_skip(DUMBFILE *f, long n);
-
- Skips n bytes of the specified DUMBFILE. Returns zero on success.
-
-
-int dumbfile_getc(DUMBFILE *f);
-
- Reads one byte from the DUMBFILE and returns it in unsigned format (from 0
- to 255). If an error occurs, or occurred before, this function returns -1.
-
-
-int dumbfile_igetw(DUMBFILE *f);
-
- Reads two bytes from the DUMBFILE and combines them into a word ranging
- from 0 to 65535. The first byte read is the least significant byte, as
- with Intel processors. This function returns -1 on error.
-
-
-int dumbfile_mgetw(DUMBFILE *f);
-
- Reads two bytes from the DUMBFILE and combines them into a word ranging
- from 0 to 65535. The first byte read is the most significant byte, as
- with the Apple Macintosh. This function returns -1 on error.
-
-
-long dumbfile_igetl(DUMBFILE *f);
-
- Reads four bytes from the DUMBFILE and combines them into a long integer
- ranging from -2147483648 to 2147483647. The first byte read is the least
- significant byte, as with Intel processors. This function returns -1 on
- error, but -1 is also a valid return value. After a call to this function,
- you can use dumbfile_error() to find out if an error occurred.
-
-
-long dumbfile_mgetl(DUMBFILE *f);
-
- Reads four bytes from the DUMBFILE and combines them into a long integer
- ranging from -2147483648 to 2147483647. The first byte read is the most
- significant byte, as with the Apple Macintosh. This function returns -1 on
- error, but -1 is also a valid return value. After a call to this function,
- you can use dumbfile_error() to find out if an error occurred.
-
-
-unsigned long dumbfile_cgetul(DUMBFILE *f);
-
- Reads an unsigned (nonnegative) integer from the DUMBFILE. The integer is
- stored in a condensed format where smaller numbers use less space:
-
- 0 to 127 1 byte
- 128 to 16383 2 bytes
- 16384 to 2097151 3 bytes
- 2097152 to 268435455 4 bytes
- 268435456 to 4294967295 5 bytes
-
- This format is the same as that used for the times between notes in MIDI
- files.
-
- If an error occurs, this function returns (unsigned long)(-1), but that
- may be a valid return value. After a call to this function, you can use
- dumbfile_error() to find out if an error occurred.
-
-
-signed long dumbfile_cgetsl(DUMBFILE *f);
-
- Reads a signed integer from the DUMBFILE. The integer is stored in a
- condensed format where numbers closer to zero use less space:
-
- -64 to 63 1 byte
- -8192 to 8191 2 bytes
- -1048576 to 1048575 3 bytes
- -134217728 to 134217727 4 bytes
- -2147483648 to 2147483647 5 bytes
-
- If an error occurs, this function returns -1, but -1 is also a valid
- return value. After a call to this function, you can use dumbfile_error()
- to find out if an error occurred.
-
-
-long dumbfile_getnc(char *ptr, long n, DUMBFILE *f);
-
- Reads n bytes from the DUMBFILE and stores them at 'ptr'. Note that the
- pointer is to a series of chars. You may also use this function to read in
- a series of signed chars or unsigned chars (which are both officially
- distinct types from char), but do not use this to read ints, structs or
- any other data type from the file. Integers must be read one at a time
- using dumbfile_igetl(), dumbfile_cgetul(), etc. To load a struct in, you
- must read each field separately using an appropriate function for each
- one. For complicated data types, you can simplify this process by writing
- a function for each struct.
-
- dumbfile_getnc() returns the number of bytes successfully read, which will
- be less than n if an error occurs, and may be as low as zero. If
- dumbfile_getnc() returns -1, that means an error occurred on this DUMBFILE
- earlier, before this function was called.
-
-
-int dumbfile_error(DUMBFILE *f);
-
- This function returns -1 if an error has occurred with the specified
- DUMBFILE, or 0 if all is well.
-
-
-int dumbfile_close(DUMBFILE *f);
-
- This function closes the DUMBFILE, after which the pointer will be
- invalid. dumbfile_close() returns the value that dumbfile_error() would
- have returned, which is -1 if an error occurred while reading or 0
- otherwise. Regardless of the return value, the file will always be closed
- properly.
-
-
-*******************************
-*** stdio File Input Module ***
-*******************************
-
-
-void dumb_register_stdfiles(void);
-
- This function registers the stdio file input module for use by DUMBFILEs.
- FILE structs and their corresponding functions, as defined by the ANSI C
- header stdio.h, will be used internally for all DUMBFILE input (unless
- opened with dumbfile_open_ex()).
-
- This must be called before dumbfile_open() is used, or else an alternative
- system must be registered (see register_dumbfile_system() and
- dumb_register_packfiles()).
-
-
-DUMBFILE *dumbfile_open_stdfile(FILE *p);
-
- If you have a stdio FILE struct representing an open file, you can call
- this if you wish to read from it using a DUMBFILE. This is useful when you
- need to pass a DUMBFILE struct to a library function, to read an embedded
- music file for example. When you close the DUMBFILE, you can continue
- using the FILE struct to read what follows the embedded data.
-
-
-********************************
-*** Memory File Input Module ***
-********************************
-
-
-DUMBFILE *dumbfile_open_memory(const char *data, long size);
-
- This function is useful if you have an image of a music file in memory.
- You might have such an image if you use dat2s to encode a datafile
- directly into the executable. Pass a pointer to the start of the memory,
- and the size of the image to make sure DUMB doesn't overrun the buffer.
- The resulting DUMBFILE will feed the contents of the image to you.
-
- Note that the pointer is of type 'char *'. Files are series of chars, and
- interpreting them directly as anything else isn't portable.
-
-
-**********************
-*** DUH Management ***
-**********************
-
-
-void unload_duh(DUH *duh);
-
- Removes a DUH from memory. You must call this for all DUHs you load,
- making sure they're not playing at the time.
-
-
-long duh_get_length(DUH *duh);
-
- Returns the length of a DUH; 65536 represents one second. This value is
- calculated when the DUH is created, and this function simply lifts it from
- the struct. It may not truly correspond to the time for which the DUH will
- generate sound. For module files, it will represent the point at which the
- module first loops (or, in the case of some XM and MOD files, freezes).
- Any add-ons to DUMB will provide their own code for calculating this.
-
- The algorithm for calculating the length of a module file can be fooled,
- but only by very deliberate methods. In the early days, when modules could
- only be played by their editors and had to be exported to .wav or similar
- in order to be used elsewhere, musicians would sometimes make the player
- think it was looping when it wasn't in order to prevent their music from
- being exported properly. If the length of a module seems a lot less than
- it should be, the module is probably protected in this way.
-
- Getting around this protection reliably would be extremely difficult, but
- after considering it for a while I decided it would be better not to. The
- musician has a right to protect his or her music in this way, and I have
- no interest in actively breaking that protection.
-
- (On the other hand, some musicians were just showing off!)
-
-
-***********************************
-*** IT, XM, S3M and MOD Support ***
-***********************************
-
-
-int dumb_it_max_to_mix;
-
- Specifies the maximum number of samples DUMB will mix at any one time. The
- default number is 64. Regardless of this value, all samples will continue
- to be processed up to an internal maximum of 256 (roughly speaking; in
- fact it will process one sample for each channel plus up to 192 extra
- samples that are continuing to play owing to Impulse Tracker's New Note
- Actions), and samples that have been cut will sound again as soon as the
- congestion clears. Samples are given priority according to their final
- volume after all factors affecting the volume of a sample have been
- considered.
-
- If you play two or more modules at once, this value represents the
- maximum number of samples for each one. You will have to reduce it further
- if your computer cannot keep up.
-
- Despite the name, this variable controls XM, S3M and MOD files as well as
- IT files.
-
-
-DUMB_IT_SIGDATA *duh_get_it_sigdata(DUH *duh);
-
- This function attempts to retrieve the DUMB_IT_SIGDATA struct from a DUH.
- This struct will exist for any IT, XM, S3M or MOD file, and you can use it
- to obtain or override module-specific information. If 'duh' is NULL, or if
- the DUH you pass contains something other than a music module, then this
- function will return NULL (which can safely be passed to any other
- function).
-
-
-DUMB_IT_SIGRENDERER *duh_get_it_sigrenderer(DUH_SIGRENDERER *sigrenderer);
-
- This function attempts to retrieve the DUMB_IT_SIGRENDERER struct from a
- DUH_SIGRENDERER. This struct will exist for any currently playing IT, XM,
- S3M or MOD file, and you can use it to obtain or override information
- specific to module playback. If 'sigrenderer' is NULL, or if the
- DUH_SIGRENDERER you pass is rendering something other than a music module,
- then this function will return NULL (which can safely be passed to any
- other function).
-
-
-DUH_SIGRENDERER *dumb_it_start_at_order
- (DUH *duh, int n_channels, int startorder);
-
- This function, given a DUH containing an IT, XM, S3M or MOD file, will
- start playing it at the specified order. If the DUH does not contain a
- module, this function will fail and return NULL.
-
- Note that starting at an arbitrary order may result in missing notes or
- other playback oddities. It should be used primarily for modules that
- contain multiple songs that start on different orders. If you wish just to
- start some music in the middle, consider using duh_start_sigrenderer() or
- al_start_duh() with the pos parameter set appropriately.
-
-
-void dumb_it_set_loop_callback(DUMB_IT_SIGRENDERER *sigrenderer,
- int (*callback)(void *data), void *data);
-
- Installs a callback which will be called every time the module loops. You
- can pass any data pointer you like, and it will be passed to the callback
- for you. DUMB considers a file to loop when it reaches the end, or when a
- 'Jump to order' effect (Bxx in both IT/S3M and XM/MOD) jumps to the same
- order or a preceding order. This can result in the loop callback being
- called when the module isn't really looping, but this only happens if the
- module has a very deliberate design. See duh_get_length() for further
- musings on this subject.
-
- If your callback returns nonzero, the music will stop abruptly. Samples
- will be cut, and the main program will be notified that the
- DUH_SIGRENDERER has ended.
-
- Alternatively, if you pass the DUMB_IT_SIGRENDERER for 'data', or
- otherwise arrange for it to be available to the callback, then you can
- call:
-
- dumb_it_sr_set_speed(sigrenderer, 0);
-
- from inside the callback, and this will cause the music to freeze but
- samples will be able to continue playing. The xm_speed_zero callback will
- NOT be called in this case (see below for information on this callback).
- Note also that setting the speed in this way will work equally for IT and
- S3M files, even though a 'speed zero' effect can only exist in XM and MOD
- files. Beware when using this method; samples might not fade at all!
-
- A helper callback, dumb_it_callback_terminate(), is provided; installing
- this will cause the music to terminate when it tries to loop for the first
- time.
-
- Pass NULL to remove the callback function; the module will then loop as
- normal.
-
-
-void dumb_it_set_xm_speed_zero_callback(DUMB_IT_SIGRENDERER *sigrenderer,
- int (*callback)(void *data), void *data);
-
- Installs a callback which is in many ways similar to the loop callback
- (see dumb_it_set_loop_callback()). This callback will be called whenever
- an F00 effect is encountered in a MOD or XM file, setting the speed to
- zero. If the callback returns nonzero, the music will terminate. If not,
- any currently playing samples will continue to play. You can pass any data
- pointer you like to this function, and it will be passed to your callback
- for you.
-
- The helper callback, dumb_it_callback_terminate(), will also work here;
- installing it will cause the music to terminate as soon as an F00 effect
- is encountered.
-
- Pass NULL to remove the callback function.
-
-
-void dumb_it_set_midi_callback(DUMB_IT_SIGRENDERER *sigrenderer,
- int (*callback)(void *data, int channel, unsigned char byte),
- void *data);
-
- Installs a callback function which will be called whenever MIDI data are
- generated by an IT file. (No other module formats are capable of
- generating MIDI data, so your callback will never be called.)
-
- Zxx macros will generate MIDI data. These are most often used to set the
- parameters for IT's low-pass resonant filters, and DUMB will handle these
- messages by itself by default. See Impulse Tracker's documentation for
- the MIDI messages that control filters. However, Zxx macros can be used
- to send any kind of MIDI data.
-
- If you wish to interpret MIDI messages yourself, you can use this
- callback. Note that the only MIDI messages generated by DUMB at present
- are from Zxx macros; there are no messages for note start, stop, or
- anything else.
-
- If you return 1 from this callback, DUMB will subsequently ignore the byte
- of MIDI data. You can use this to prevent Zxx macros from controlling the
- filters, useful if they were intended to do something else. Note that this
- is NOT an effective way to disable filters, since instruments can have
- filter envelopes and initial filter parameters. DUMB provides no means to
- disable filters, as any IT file that uses them will sound wrong without
- them. If you want lower processor consumption, use a different piece of
- music.
-
- A helper callback, dumb_it_callback_midi_block(), is provided for blocking
- all MIDI messages and making Zxx macros do nothing.
-
- Pass NULL to remove the callback.
-
-
-int dumb_it_callback_terminate(void *data);
-
- This is a helper callback that can be installed with both
- dumb_it_set_loop_callback() and dumb_it_set_xm_speed_zero_callback(). In
- each case it will cause the music to terminate abruptly.
-
-
-int dumb_it_callback_midi_block(void *data, int channel, unsigned char byte);
-
- This helper callback, for use with dumb_it_set_midi_callback(), will
- absorb all MIDI messages, returning 1 to prevent DUMB from interpreting
- them itself.
-
-
-DUH *dumb_load_it(const char *filename);
-
- Loads the specified Impulse Tracker file, encapsulating it in a DUH
- struct. Once the file is loaded, it can be treated exactly the same as any
- other DUH in memory. If this fails it will return NULL, but you can safely
- pass this NULL value to DUMB's other functions, so you do not need to
- check the return value explicitly.
-
-
-DUH *dumb_read_it(DUMBFILE *f);
-
- Reads an Impulse Tracker file from an already open DUMBFILE. This leaves
- the DUMBFILE open, but the DUMBFILE may not be positioned at the end of
- the IT data. If you are embedding an IT in another file, you are advised
- to store the size of the IT file and make up for it at the end using
- dumbfile_pos().
-
- Otherwise, this function is identical to dumb_load_it().
-
- WARNING: The behaviour of this function is undefined if you pass a
- DUMBFILE from which data have already been read; it is likely not
- to work. This oversight will be fixed in future releases.
-
-
-DUH *dumb_load_xm(const char *filename);
-
- Loads the specified Fast Tracker II file, encapsulating it in a DUH
- struct. Once the file is loaded, it can be treated exactly the same as any
- other DUH in memory. If this fails it will return NULL, but you can safely
- pass this NULL value to DUMB's other functions, so you do not need to
- check the return value explicitly.
-
-
-DUH *dumb_read_xm(DUMBFILE *f);
-
- Reads a Fast Tracker II file from an already open DUMBFILE. This leaves
- the DUMBFILE open, but the DUMBFILE may not be positioned at the end of
- the XM data. If you are embedding an XM in another file, you are advised
- to store the size of the XM file and make up for it at the end using
- dumbfile_pos().
-
- Otherwise, this function is identical to dumb_load_xm().
-
- WARNING: The behaviour of this function is undefined if you pass a
- DUMBFILE from which data have already been read; it is likely not
- to work. This oversight will be fixed in future releases.
-
-
-DUH *dumb_load_s3m(const char *filename);
-
- Loads the specified Scream Tracker 3 file, encapsulating it in a DUH
- struct. Once the file is loaded, it can be treated exactly the same as any
- other DUH in memory. If this fails it will return NULL, but you can safely
- pass this NULL value to DUMB's other functions, so you do not need to
- check the return value explicitly.
-
-
-DUH *dumb_read_s3m(DUMBFILE *f);
-
- Reads a Scream Tracker 3 file from an already open DUMBFILE. This leaves
- the DUMBFILE open, but the DUMBFILE may not be positioned at the end of
- the S3M data. If you are embedding an S3M in another file, you are advised
- to store the size of the S3M file and make up for it at the end using
- dumbfile_pos().
-
- Otherwise, this function is identical to dumb_load_s3m().
-
- WARNING: The behaviour of this function is undefined if you pass a
- DUMBFILE from which data have already been read; it is likely not
- to work. This oversight will be fixed in future releases.
-
-
-DUH *dumb_load_mod(const char *filename);
-
- Loads the specified Amiga module file, encapsulating it in a DUH struct.
- Once the file is loaded, it can be treated exactly the same as any other
- DUH in memory. If this fails it will return NULL, but you can safely pass
- this NULL value to DUMB's other functions, so you do not need to check the
- return value explicitly.
-
-
-DUH *dumb_read_mod(DUMBFILE *f);
-
- Reads an Amiga module file from an already open DUMBFILE. This leaves the
- DUMBFILE open, but the DUMBFILE may not be positioned at the end of the
- MOD data. If you are embedding a MOD in another file, you are advised to
- store the size of the MOD file and make up for it at the end using
- dumbfile_pos().
-
- Otherwise, this function is identical to dumb_load_mod().
-
- WARNING: The behaviour of this function is undefined if you pass a
- DUMBFILE from which data have already been read; it is likely not
- to work. This oversight will be fixed in future releases.
-
-
-int dumb_it_sd_get_n_orders(DUMB_IT_SIGDATA *sd);
-
- This function returns the number of orders in the module.
-
-
-int dumb_it_sd_get_initial_global_volume(DUMB_IT_SIGDATA *sd);
-void dumb_it_sd_set_initial_global_volume(DUMB_IT_SIGDATA *sd, int gv);
-
- These functions obtain and set the initial global volume for the module.
- This value ranges from 0 to 128 inclusive. The module can set the global
- volume itself during playback, so your change may not last throughout the
- playback.
-
-
-int dumb_it_sd_get_mixing_volume(DUMB_IT_SIGDATA *sd);
-void dumb_it_sd_set_mixing_volume(DUMB_IT_SIGDATA *sd, int mv);
-
- These functions obtain and set the mixing volume for the module. This
- value ranges from 0 to 128 inclusive, and does not change during playback.
- IT files have the mixing volume stored in them; for other formats it is
- set to 48 on loading.
-
-
-int dumb_it_sd_get_initial_speed(DUMB_IT_SIGDATA *sd);
-void dumb_it_sd_set_initial_speed(DUMB_IT_SIGDATA *sd, int speed);
-int dumb_it_sd_get_initial_tempo(DUMB_IT_SIGDATA *sd);
-void dumb_it_sd_set_initial_tempo(DUMB_IT_SIGDATA *sd, int tempo);
-
- These functions obtain and set the initial speed and tempo for the module.
- During module playback, everything happens on a tick. If a beat is 24
- ticks, then the tempo is measured in beats per second. The speed is then
- the number of ticks per row. With a speed of 6, a beat is then four rows.
-
- Modules can set these values during playback, so your change may not last
- throughout the playback. MOD files have to set the speed and tempo on the
- first row if they want anything other than the default 6/125, so your
- change may not be noticed at all!
-
-
-int dumb_it_sd_get_initial_channel_volume(DUMB_IT_SIGDATA *sd, int channel);
-void dumb_it_sd_set_initial_channel_volume(DUMB_IT_SIGDATA *sd, int channel,
- int volume);
-
- These functions obtain and set the initial volume for the specified
- channel. The channel parameter is 0-based (contrary to the display in most
- trackers so be careful), and can range from 0 to DUMB_IT_N_CHANNELS - 1,
- i.e. from 0 to 63.
-
- Modules can set their channel volumes during playback, so your changes may
- not last throughout the playback.
-
-
-int dumb_it_sr_get_current_order(DUMB_IT_SIGRENDERER *sr);
-int dumb_it_sr_get_current_row(DUMB_IT_SIGRENDERER *sr);
-
- These functions return the current order and row of playback. Both are
- 0-based. If the DUMB_IT_SIGRENDERER is invalid, or has been terminated
- by a callback (see dumb_it_set_loop_callback() and
- dumb_it_set_xm_speed_zero_callback()), these functions will both return
- -1.
-
-
-int dumb_it_sr_get_global_volume(DUMB_IT_SIGRENDERER *sr);
-void dumb_it_sr_set_global_volume(DUMB_IT_SIGRENDERER *sr, int gv);
-
- These functions obtain and set the current global volume for the module.
- This value ranges from 0 to 128 inclusive. The module can set the global
- volume itself during playback, so your change may not last.
-
-
-int dumb_it_sr_get_tempo(DUMB_IT_SIGRENDERER *sr);
-void dumb_it_sr_set_tempo(DUMB_IT_SIGRENDERER *sr, int tempo);
-int dumb_it_sr_get_speed(DUMB_IT_SIGRENDERER *sr);
-void dumb_it_sr_set_speed(DUMB_IT_SIGRENDERER *sr, int speed);
-
- These functions obtain and set the current speed and tempo of the module.
- See the dumb_it_sd_*() equivalents of these functions for details on what
- the speed and tempo mean.
-
- Modules can set these values during playback, so your change may not last.
-
-
-int dumb_it_sr_get_channel_volume(DUMB_IT_SIGRENDERER *sr, int channel);
-void dumb_it_sr_set_channel_volume(DUMB_IT_SIGRENDERER *sr, int channel,
- int volume);
-
- These functions obtain and set the current volume for the specified
- channel. The channel parameter is 0-based (contrary to the display in most
- trackers so be careful), and can range from 0 to DUMB_IT_N_CHANNELS - 1,
- i.e. from 0 to 63.
-
- Modules can set their channel volumes during playback, so your changes may
- not last.
-
-
-void dumb_it_sr_get_channel_state(DUMB_IT_SIGRENDERER *sr, int channel,
- DUMB_IT_CHANNEL_STATE *state);
-
- Returns the current playback state of the given channel. If you pass a
- channel in the range 0 to DUMB_IT_N_CHANNELS-1 (0 to 63), you will get the
- state of the most recently played note on that physical channel, if it is
- still playing. For MOD, S3M and XM files, that's all there is to it.
-
- IT files can have more than one note playing on a single channel, courtesy
- of New Note Actions. This function also lets you query all the notes that
- have been forced into the background and are still playing. For this, set
- 'channel' to a value from DUMB_IT_N_CHANNELS to DUMB_IT_TOTAL_CHANNELS-1.
- DUMB_IT_TOTAL_CHANNELS is defined as follows:
-
- #define DUMB_IT_TOTAL_CHANNELS \
- (DUMB_IT_N_CHANNELS + DUMB_IT_N_NNA_CHANNELS)
-
- Querying these background channels for MOD, S3M and XM files will not do
- any harm; the function will report that these channels are inactive. For
- all files, be sure not to query any channel numbers greater than or equal
- to DUMB_IT_TOTAL_CHANNELS.
-
- You must provide a pointer to a preallocated DUMB_IT_CHANNEL_STATE struct.
- The easiest way to do this is as follows:
-
- DUMB_IT_CHANNEL_STATE state;
- dumb_it_sr_get_channel_state(sr, channel, &state);
-
- or:
-
- DUMB_IT_CHANNEL_STATE state[IT_TOTAL_CHANNELS];
- dumb_it_sr_get_channel_state(sr, channel, &state[channel]);
-
- This struct contains the following fields:
-
- int channel;
- int sample;
- int freq;
- float volume;
- unsigned char pan;
- signed char subpan;
- unsigned char filter_cutoff;
- unsigned char filter_subcutoff;
- unsigned char filter_resonance;
-
- The first field to check is 'sample'; if this is 0, then the channel is
- inactive and the other fields are undefined. Otherwise, it is the index of
- the currently playing sample, and is 1-based.
-
- The channel number is returned, 0-based. This will be the same as the
- channel number you passed, unless you are querying a background channel in
- which case it will represent the channel the note originated on.
-
- The freq field is the current playback frequency, taking into account all
- phenomena such as slides, vibrato and arpeggio.
-
- The volume field ranges from 0.0f to 1.0f. In practical terms, it will
- rarely reach 1.0f; if it does, the module is probably clipping a lot. This
- takes mixing volume into account, along with all the other volume
- phenomena in the IT file. The only one it doesn't take into account is the
- one you pass to duh_render() or duh_sigrenderer_get_samples(), or the one
- you passed to al_start_duh() (these are in fact the same thing).
-
- The pan field ranges from 0 to 64 for a normally panned sample, but will
- be 100 if the sample is playing using IT's surround mode where the right-
- hand channel is inverted. If you want a more accurate pan reading, use one
- of the following to get one:
-
- int scaled_pan = ((int)state.pan << 8) + state.subpan;
- float float_pan = state.pan + state.subpan / 256.0f;
-
- The first will give a scaled value ranging (strictly) from 0 to 64*256.
- The second will give a floating-point value whose scale corresponds to
- that of the pan field. These results will only be valid if surround mode
- is off, so you should check that pan <= 64 before using the above
- expressions. At the time of writing, pitch-pan separation and panning
- envelopes take advantage of the extra accuracy offered by subpan.
-
- Note that subpan is signed. This means applications that only look at the
- pan field will get an unbiased reading.
-
- The filter cut-off and resonance both range from 0 to 127. If the cut-off
- is 127 and the resonance is 0, then no filters are applied. These
- parameters only ever change from the default values for IT files.
-
- While IT allows you to set 127 different filter cut-off levels in the
- patterns and as a default value per instrument, it also allows you to
- create a filter envelope, which will result in an actual cut-off somewhere
- between 0 and the first-mentioned value. By the time this has been
- calculated, the actual cut-off may lie in between two levels on the
- original scale. If this is the case, filter_subcutoff will be nonzero and
- you can combine it with filter_cutoff. Typically you will want to use one
- of the following:
-
- int scaled_cutoff = ((int)state.filter_cutoff << 8) +
- state.filter_subcutoff;
-
- float float_cutoff = state.filter_cutoff +
- state.filter_subcutoff / 256.0f;
-
- The first will give you a scaled value whose maximum is 127*256. The
- second will give you a floating-point value whose scale corresponds to the
- scale used by filter_cutoff. These match the expressions given further up
- for pan and subpan, but in this case, filter_subcutoff is unsigned.
-
- Note that filter_subcutoff will always be zero if filter_cutoff is 127, so
- you need not check it if you simply wish to determine whether filters are
- being applied.
-
-
-*******************************
-*** DUH Rendering Functions ***
-*******************************
-
-
- Use these functions to generate samples from a DUH. First you call
- duh_start_sigrenderer() with the DUH, the number of channels you want and
- the position at which you want to start. Then you use duh_render() or
- duh_sigrenderer_get_samples() to generate the samples. You can call these
- functions as many times as you like, and they will generate as many or as
- few samples as you require. When you have finished, call
- duh_end_sigrenderer().
-
-
-DUH_SIGRENDERER *duh_start_sigrenderer
- (DUH *duh, int sig, int n_channels, long pos);
-
- Starts a DUH_SIGRENDERER off. This is the struct you can use to get
- samples from a DUH. This function does not generate any samples; you must
- pass the struct to duh_render() or duh_sigrenderer_get_samples() for that.
- When you have finished with it, you must pass it to duh_end_sigrenderer().
- You can use as many DUH_SIGRENDERER structs as you like at the same time.
-
- Set sig to 0 for now. Currently, n_channels can only be 1 or 2, for
- monaural and stereo sound respectively. The debugging library will cause
- your program to abort if you pass anything else. Future versions will be
- enhanced to support more channels as soon as someone needs them.
-
- When specifying the position, 0 represents the start of the DUH, and 65536
- represents one second. Unlike most other music systems, DUMB will always
- make sure every note is there right from the start (assuming you aren't
- using any broken add-ons). In other words, you can start a DUH at a point
- halfway through a long note, and you will still hear the long note.
-
-
-void duh_sigrenderer_set_analyser_callback(DUH_SIGRENDERER *sigrenderer,
- DUH_SIGRENDERER_ANALYSER_CALLBACK callback, void *data);
-
- Installs a callback function which will be called every time the given
- sigrenderer is used to generate some samples. This can be used to create
- an oscilloscope or spectrum analyser. DUH_SIGRENDERER_ANALYSER_CALLBACK is
- defined as follows:
-
- typedef void (*DUH_SIGRENDERER_ANALYSER_CALLBACK)(void *data,
- const sample_t *const *samples, int n_channels, long length);
-
- If the above confuses you, see fnptr.txt. As for the 'samples' parameter,
- the first 'const' says that the samples are read-only; the second says
- that each channel's sample pointer is also read-only. If you don't
- understand this, don't worry about it.
-
- Beware: your callback function may occasionally be called with
- samples == NULL. This means the main program has decided to skip through
- the music without generating any data (see duh_sigrenderer_get_samples()).
- You should handle this case elegantly, typically by returning immediately,
- but you may wish to make a note of the fact that the music is being
- skipped, for whatever reason.
-
- Beware again: if the main program ever calls duh_sigrenderer_get_samples()
- on a buffer that isn't all silence, this callback function will be passed
- the existing buffer after mixing, and thus it will include the original
- data. This will not be an issue if you stick to duh_render(), which always
- starts with a buffer filled with silence.
-
- The samples array is two-dimensional. Refer to it as follows:
-
- samples[channel_number][sample_position]
-
- where 0 <= channel_number < n_channels,
- and 0 <= sample_position < length.
-
- In addition you can pass any 'data' pointer you like to
- duh_sigrenderer_set_analyser_callback(), and this pointer will be relayed
- to your callback function each time.
-
- To remove the callback function, pass NULL to
- duh_sigrenderer_set_analyser_callback().
-
-
-int duh_sigrenderer_get_n_channels(DUH_SIGRENDERER *sigrenderer);
-
- Tells you how many channels a DUH_SIGRENDERER is set up to generate, or 0
- if it is invalid (perhaps owing to lack of memory). This will be 1 for
- monaural sound or 2 for stereo, in this release.
-
-
-long duh_sigrenderer_get_position(DUH_SIGRENDERER *sigrenderer);
-
- Tells you what position a DUH_SIGRENDERER is up to, or -1 if it is invalid
- (perhaps owing to lack of memory). As usual, 65536 is one second.
-
-
-long duh_sigrenderer_get_samples(DUH_SIGRENDERER *sigrenderer,
- float volume, float delta,
- long size, sample_t **samples);
-
- Generates some samples in DUMB's internal 32-bit format (see sample_t; see
- also duh_render()). The samples buffer is a two-dimensional array, and can
- be allocated with create_sample_buffer(); see
- duh_sigrenderer_set_analyser_callback() for details.
- duh_sigrenderer_get_samples() mixes sample data with what's already in the
- buffer, so you have to call dumb_silence() first.
-
- The volume is a float. 1.0f is the pseudo-maximum. If you pass 1.0f, any
- properly designed DUH will play nice and loud, but will not clip. You can
- pass a greater volume if you like, but be prepared for the possibility of
- distortion due to integer overflow. Of course you can pass smaller values
- to play the DUH more quietly, and this will also resolve clipping issues
- in badly designed DUHs.
-
- Use delta to control the speed of the output signal. If you pass 1.0f, the
- resultant signal will be suitable for a 65536-Hz sampling rate (which
- isn't a commonly used rate). The most common sampling rates are 11025 Hz,
- 22050 Hz, 44100 Hz and 48000 Hz. You can work out the required delta value
- as follows:
-
- delta = 65536.0f / sampling_rate;
-
- If you then increase this value, the DUH will speed up and increase in
- pitch. If you decrease it, the DUH will slow down and decrease in pitch.
-
- This function will attempt to render 'size' samples. In most cases it will
- succeed. However, if the end of the DUH is reached, it may render fewer.
- The number of samples rendered will be returned. Therefore, if the return
- value is less than the value of 'size' passed, you know the DUH has
- finished. It is safe to continue calling duh_sigrenderer_get_samples() if
- you wish, and it will continually return 0.
-
- If the DUH_SIGRENDERER is a null pointer, this function will generate
- precisely 0 samples. If you pass NULL for 'samples', the function will
- behave exactly the same as if you provided a sample buffer, except the
- samples won't be stored anywhere and the function will execute very
- quickly. This can be used to skip ahead in the audio.
-
-
-long duh_render(DUH_SIGRENDERER *sigrenderer,
- int bits, int unsign,
- float volume, float delta,
- long size, void *sptr);
-
- Generates some samples and converts them to an 8-bit or 16-bit format (see
- also duh_sigrenderer_get_samples()). Pass the DUH_SIGRENDERER as returned
- by duh_start_sigrenderer(). Pass the number of bits, which should be 8 or
- 16. If unsign is nonzero, the samples will be unsigned (centred on 0x80 or
- 0x8000 for 8 bits and 16 bits respectively). If unsign is zero, the
- samples will be signed.
-
- Allegro's audio streams always take unsigned samples. 8-bit .wav files
- always take unsigned samples. 16-bit .wav files always take signed
- samples.
-
- The volume and delta parameters work the same as for
- duh_sigrenderer_get_samples().
-
- This function will attempt to render 'size' samples. In most cases it will
- succeed. However, if the end of the DUH is reached, it may render fewer.
- The number of samples rendered will be returned. Therefore, if the return
- value is less than the value of 'size' passed, you know the DUH has
- finished. It is safe to continue calling duh_render() if you wish, and it
- will continually return 0. However, if you wish to do this, you will
- probably have to fill the rest of the buffer with silence, which is 0 for
- signed, 0x80 for 8-bit unsigned or 0x8000 for 16-bit unsigned.
-
- The samples will be placed at sptr. Use an array of chars for 8 bits or an
- array of shorts for 16 bits. Stereo samples will be interleaved, left
- first. Your array should contain at least (size * n_channels) elements of
- the appropriate bit resolution.
-
- From an aesthetic standpoint if nothing else, it is wise to use the C
- qualifiers 'signed' or 'unsigned' depending on whether the samples are
- signed or unsigned. This is also convenient if you wish to process the
- samples further yourself.
-
- If the DUH_SIGRENDERER is a null pointer, this function will generate
- precisely 0 samples. Unlike with duh_sigrenderer_get_samples(), you must
- specify a sample buffer.
-
-
-void duh_end_sigrenderer(DUH_SIGRENDERER *dr);
-
- Terminates a DUH_SIGRENDERER. Be sure to call this when you've finished
- with one. You can safely pass a null pointer.
-
-
-********************************
-*** Allegro Packfile Support ***
-********************************
-
-
-void dumb_register_packfiles(void);
-
- This function registers the Allegro PACKFILE input module for use by
- DUMBFILEs. PACKFILE structs and their corresponding functions, as defined
- by Allegro's header file allegro.h, will be used internally for all
- DUMBFILE input (unless opened with dumbfile_open_ex()).
-
- This must be called before dumbfile_open() is used, or else an alternative
- system must be registered (see register_dumbfile_system() and
- dumb_register_stdfiles()). Note that you don't have to call this function
- in order to load datafiles that contain music.
-
-
-DUMBFILE *dumbfile_open_packfile(PACKFILE *p);
-
- If you have an Allegro PACKFILE struct representing an open file, you can
- call this if you wish to read from it using a DUMBFILE. This is useful
- when you need to pass a DUMBFILE struct to a library function, to read an
- embedded music file for example. When you close the DUMBFILE, you can
- continue using the PACKFILE struct to read what follows the embedded data.
-
-
-DUMBFILE *dumbfile_from_packfile(PACKFILE *p);
-
- This function is the same as dumbfile_open_packfile(), except it will
- check if p is NULL, and arrange for pack_fclose() to be called on the
- PACKFILE when you close the DUMBFILE. It can be seen as a function for
- converting a PACKFILE to a DUMBFILE, but it will only work for a PACKFILE
- you obtained with pack_fopen(), not pack_fopen_chunk(). If this function
- fails, which may happen if memory is short, then the PACKFILE will be
- closed immediately, so you need not worry about potential memory leaks or
- files being left open when this happens.
-
- The following is typical usage, and will open the compressed file foo.bin:
-
- DUMBFILE *f = dumbfile_from_packfile(pack_fopen("foo.bin",
- F_READ_PACKED));
-
- This differs from calling dumb_register_packfiles() and dumbfile_open() in
- that the latter will only read uncompressed files (and is thus a method
- suitable for reading music modules).
-
-
-***********************************************
-*** Allegro Datafile Registration Functions ***
-***********************************************
-
-
-void dumb_register_dat_it(long type);
-
- If you wish to embed an IT file in an Allegro datafile, it is recommended
- that you use "IT " for the type. The grabber will have a box for the type
- when you insert a new object. The grabber will treat the IT file as binary
- data, which means the datafile will contain an exact copy of the IT file
- on disk.
-
- You must then call dumb_register_dat_it(DUMB_DAT_IT) in your program
- before you load the datafile. Once you've done this, you'll be able to
- access the DUH using the usual datafile[n].dat notation. You do not need
- to call unload_duh() on this DUH; unload_datafile() will do that for you.
-
- If you are using a different type for whatever reason, you can use
- Allegro's DAT_ID() macro for encoding it and passing it to this function.
- For example:
-
- dumb_register_dat_it(DAT_ID('B','L','A','H'));
-
- Assuming you used the recommended type, the following example iterates
- through all the ITs in disan.dat:
-
- DATAFILE *dat;
- int n;
-
- dumb_register_dat_it();
- dat = load_datafile("disan.dat");
-
- for (n = 0; dat[n].type != DAT_END; n++) {
- if (dat[n].type == DUMB_DAT_IT) {
- DUH *duh = dat[n].dat;
- /* Insert code here to play 'duh' or whatever you want to do. */
- }
- }
-
- unload_datafile(dat);
-
-
-void dumb_register_dat_xm(long type);
-
- Inserting an XM file in an Allegro datafile is the same as inserting an IT
- file, except that the recommended type is "XM ", the registration
- function is dumb_register_dat_xm(), and the macro DUMB_DAT_XM is provided
- for the type. The intuitive process of substituting XM for IT in the above
- method will work.
-
-
-void dumb_register_dat_s3m(long type);
-
- Inserting an S3M file in an Allegro datafile is the same as inserting an
- IT file, except that the recommended type is "S3M ", the registration
- function is dumb_register_dat_s3m(), and the macro DUMB_DAT_S3M is
- provided for the type. The intuitive process of substituting S3M for IT in
- the above method will work.
-
-
-void dumb_register_dat_mod(long type);
-
- Inserting a MOD file in an Allegro datafile is the same as inserting an IT
- file, except that the recommended type is "MOD ", the registration
- function is dumb_register_dat_mod(), and the macro DUMB_DAT_MOD is
- provided for the type. The intuitive process of substituting MOD for IT in
- the above method will work.
-
-
-****************************************
-*** Sample Buffer Allocation Helpers ***
-****************************************
-
-
- Many parts of DUMB require sample buffers allocated in a special way. A
- pointer to one looks like this:
-
- sample_t **samples;
-
- and it can be indexed as follows:
-
- samples[channel_number][sample_position]
-
- where 0 <= channel_number < n_channels
- and 0 <= sample_position < length.
-
- The following helpers will allocate and deallocate such buffers for you.
- They will not initialise them, and DUMB always writes into these buffers
- by adding to what's already there, so you will generally have to call
- dumb_silence() too.
-
-
-sample_t **create_sample_buffer(int n_channels, long length);
-
- This will allocate a sample buffer to hold the specified number of samples
- for the specified number of channels. Don't forget to check the return
- value!
-
- You will generally have to initialise the buffer by calling
- dumb_silence(); the channels will be stored consecutively in memory, so
- the following technique is officially supported:
-
- dumb_silence(samples[0], n_channels * length);
-
- See dumb_silence() for general information on what this function does.
-
-
-void destroy_sample_buffer(sample_t **samples);
-
- This function does the obvious: it frees up a sample buffer when you've
- finished with it. It is safe to pass a null pointer to this function.
-
-
-************************
-*** Silencing Helper ***
-************************
-
-
-void dumb_silence(sample_t *samples, long length);
-
- This function simply stores 'length' samples' worth of silence in the
- array. It is typically used straight after allocating a sample buffer with
- create_sample_buffer().
-
-
-**************************
-*** Resampling Helpers ***
-**************************
-
-
- Please forgive the odd section name; it has to do with DUMB's internal
- structure and the fact that the resampling algorithm is there not just for
- use in rendering module files but for use anywhere that a waveform needs
- resampling. Unfortunately DUMB's resampling algorithm is not ready to be
- documented and used yet. However, one thing can be documented, and that's
- the global variable controlling the resampling quality.
-
- (Ironically, even this variable has changed! See deprec.txt for
- information on what it used to do.)
-
-
-int dumb_resampling_quality;
-
- Allows you to control the quality of all resampling that takes place. This
- may be set to any DUMB_RQ_* constant (except DUMB_RQ_N_LEVELS). Higher
- values will sound better, but lower values will use up less processor
- time. You may compare any two DUMB_RQ_* constants or values using the
- integer inequalities <, <=, > and >=; higher numbers represent higher-
- quality algorithms.
-
- #define DUMB_RQ_ALIASING
-
- | --___ 'Aliasing' has very noticeable and usually unwanted
- |__--- __ overtones. It will occasionally produce acceptable
- | ___-- results for noisy (impure) samples (or for cheap
- speakers!), but usually you will want to pay for
- the extra processor time, which isn't much, and go for linear
- interpolation.
-
- #define DUMB_RQ_LINEAR
-
- | __ Linear interpolation is a pretty good algorithm in most
- | / \ /\ cases. When resampling down a few octaves, however, you
- |/ \/ \__ may begin to notice unwanted high frequencies. You can
- reduce these by switching to cubic interpolation, but it
- will cost you some processor time.
-
- #define DUMB_RQ_CUBIC
-
- Cubic interpolation looks like a smooth curve to the eye, and will
- produce good results in most cases. At present this is the highest
- quality offered by DUMB, and also the default. While this may seem
- extravagant, GCC 3.x and an AthlonXP handle it quite well - and the
- general trend is for processors to get better!
-
- #define DUMB_RQ_N_LEVELS
-
- This represents the number of resampling quality levels DUMB provides.
- Values of dumb_resampling_quality from 0 to DUMB_RQ_N_LEVELS - 1 are
- valid. You can use this constant if you wish to offer the resampling
- quality as an option for the user.
-
-
-*************************************
-*** Allegro DUH Playing Functions ***
-*************************************
-
-
- The functions in this section allow you to play back a DUH through
- Allegro's sound system. You must call Allegro's install_sound() function
- before you use them.
-
-
-AL_DUH_PLAYER *al_start_duh(DUH *duh, int n_channels, long pos,
- float volume, long bufsize, int freq);
-
- Starts playing the specified DUH.
-
- An AL_DUH_PLAYER represents one instance of the DUH playing. If you wish,
- you can have two or more AL_DUH_PLAYERs going at the same time, for the
- same DUH or for different ones. Each uses one of Allegro's audio streams
- and hence one voice. The voice will be given priority 255 initially, so a
- build-up of sound effects will not cause your music streams to cut off (as
- long as you don't give all your sound effects priority 255!). You can
- change the priority of a stream with al_duh_set_priority(). See Allegro's
- documentation for more information on how voice priorities work.
-
- At present, n_channels can either be 1 or 2 for monaural or stereo
- respectively. If you use the debugging library, your program will abort if
- other values are passed; otherwise weird things will happen.
-
- The DUH will start playing from position 'pos'. 0 represents the start of
- the DUH, and 65536 represents one second. Unlike other music systems, DUMB
- will always make sure every note is there right from the start. In other
- words, you can start a DUH at a point halfway through a long note, and you
- will still hear the long note.
-
- The volume is a float. 1.0f is the pseudo-maximum. If you pass 1.0f, any
- properly designed DUH file will play nice and loud, but will not clip. You
- can pass a greater volume if you like, but be prepared for clipping to
- occur. Of course you can pass smaller values to play the DUH more quietly,
- and this will also resolve clipping issues in badly designed DUH files.
-
- You will need to pass the AL_DUH_PLAYER to other functions when you need
- to stop or pause the DUH, change its volume, or otherwise modify the way
- it is playing. You will also need to pass it to al_poll_duh() at regular
- intervals; if the sound is choppy, try calling al_poll_duh() more often.
-
- 'bufsize' is the number of samples that will be rendered at once. 1024 is
- a suitable value for most purposes. The greater this is, the less often
- you will have to call al_poll_duh() - but when al_poll_duh() decides to
- fill the buffer, it will take longer doing so. If your game exhibits
- regular brief freezes, try reducing the buffer size. If the sound is
- choppy, however, you may have to increase it.
-
- 'freq' specifies the sampling frequency at which the DUH should be
- rendered. At present there is no (official and portable) way of knowing
- the frequency at which Allegro is mixing - but if you do know that
- frequency, passing it here will give the highest quality sound. If you
- reduce it, the DUH will sound less crisp but use less processor time.
-
- When you have finished, you must pass the AL_DUH_PLAYER to al_stop_duh()
- to free up memory. Do not destroy the DUH beforehand.
-
- There is no real need to check the return value from this function. The
- other functions can be called safely with null pointers, so if there is a
- problem, your music will simply not play.
-
-
-void al_stop_duh(AL_DUH_PLAYER *dp);
-
- This will stop an AL_DUH_PLAYER. You must call this when you have finished
- with it, before destroying the DUH. The pointer will no longer be valid on
- return from this function.
-
-
-void al_pause_duh(AL_DUH_PLAYER *dp);
-
- This will pause an AL_DUH_PLAYER. Use al_resume_duh() when you want it to
- continue. You can safely call al_poll_duh() while the music is paused, and
- it will do nothing.
-
-
-void al_resume_duh(AL_DUH_PLAYER *dp);
-
- Causes a paused AL_DUH_PLAYER to resume playing (see al_pause_duh()).
-
-
-void al_duh_set_priority(AL_DUH_PLAYER *dp, int priority);
-
- This will set the priority of the audio stream underlying an
- AL_DUH_PLAYER. The priority is an integer ranging from 0 to 255. When
- too many samples play at the same time, those with lower priorities will
- be cut. 128 is the usual default with Allegro, but DUMB overrides the
- default for all AL_DUH_PLAYER structs: they will be set up initially with
- priority 255, so your music won't be cut (unless you play too many other
- streams or samples with priority 255). See Allegro's documentation for
- more information on priorities.
-
-
-void al_duh_set_volume(AL_DUH_PLAYER *dp, float volume);
-
- This will set the volume of an AL_DUH_PLAYER. See al_start_duh() for
- details on the volume parameter.
-
-
-int al_poll_duh(AL_DUH_PLAYER *dp);
-
- An AL_DUH_PLAYER is not interrupt-driven. That means it will not play by
- itself. You must keep it alive from your main program. Call this function
- at regular intervals. If the sound crackles, try calling it more often.
- (There is nothing you can do if Windows decides to play with the hard
- disk; that will make your sound crackle no matter what you do.)
-
- Normally this function will return zero. However, if it returns nonzero,
- that means the AL_DUH_PLAYER will not generate any more sound. Indeed the
- underlying audio stream and DUH_SIGRENDERER have been destroyed. When this
- happens, you can call al_stop_duh() whenever you wish - but you do not
- have to. Note that this function will wait two buffers' worth of samples
- before taking this action, allowing Allegro to mix the trailing sound
- before the audio stream is destroyed. This is an attempt to make sure your
- music does not get cut off prematurely, and it should work when using
- Allegro's mixer (the only option on DOS, the default on Linux as far as I
- know, but not the default on Windows). That said, if you immediately call
- Allegro's remove_sound() or exit your program, the music may get cut off.
- If you are using another mixer and experience problems, let me know (but I
- don't guarantee to be able to come up with an elegant solution, i.e. it
- might not get fixed).
-
- In case you were wondering, it is not safe on all platforms to call
- al_poll_duh() from an interrupt context (that means an Allegro timer
- handler). Not only is no part of DUMB locked in memory, but many parts of
- DUMB allocate and free their memory on a call-by-call basis! Remember that
- any disk access that occurs in interrupt context is likely to crash the
- machine; this is explained more fully in howto.txt. This limitation only
- applies to DOS at present, and is due to the fact that the DOS file access
- functions are not re-entrant.
-
- Multitasking systems are generally safe. If you are sure you don't want to
- target DOS, you can call al_poll_duh() from inside a timer handler, but I
- recommend including a construction like the following!
-
- #ifdef ALLEGRO_DOS
- #error calling al_poll_duh() from a timer handler will not work in DOS!
- #endif
-
- Furthermore, if you call al_poll_duh() from inside a timer handler, you
- must use a semaphore or other threading mechanism to make sure it is not
- executing when you call al_stop_duh(). If you don't know what a semaphore
- is, for Heaven's sake follow my advice and call al_poll_duh() from your
- main loop!
-
-
-long al_duh_get_position(AL_DUH_PLAYER *dp);
-
- Tells you what position an AL_DUH_PLAYER is up to, or -1 if it is invalid
- (perhaps owing to lack of memory). As usual, 65536 is one second. Note
- that this is a whole number, whereas a fractional part is stored
- internally; the sample will not be continuous if you terminate the
- AL_DUH_PLAYER and then reinitiate it with the same position. Furthermore,
- note that Allegro will not have mixed in all the sound up to this point;
- if you wait for this to reach a certain position and then terminate the
- AL_DUH_PLAYER, the sound will cut off too early. Please contact me if you
- need to get around this.
-
-
-AL_DUH_PLAYER *al_duh_encapsulate_sigrenderer
- (DUH_SIGRENDERER *sigrenderer, float volume, long bufsize, int freq);
-
- If you have a DUH_SIGRENDERER, and would like to start playing music from
- it through an Allegro audio stream, use this function. Beware that it may
- return NULL, in which case you will have to call duh_end_sigrenderer()
- yourself instead of relying on the encapsulating AL_DUH_PLAYER to do it
- for you.
-
-
-DUH_SIGRENDERER *al_duh_get_sigrenderer(AL_DUH_PLAYER *dp);
-
- This returns the DUH_SIGRENDERER contained in an AL_DUH_PLAYER, useful for
- controlling playback, installing callbacks, etc.
-
-
-DUH_SIGRENDERER *al_duh_decompose_to_sigrenderer(AL_DUH_PLAYER *dp);
-
- This destroys an AL_DUH_PLAYER, but preserves the DUH_SIGRENDERER it
- contains, and returns it to you. You can then continue rendering samples
- from the DUH_SIGRENDERER and do whatever you like with them.
-
-
-*********************
-*** Thread Safety ***
-*********************
-
-
-The following points should pretty much sum up the essence of DUMB's thread
-safety. If I haven't covered the one thing you'd like to do, please don't
-hesitate to ask about it.
-
-DOs:
-
-- You may load and use multiple DUHs in separate threads.
-
-- You may change dumb_resampling_quality and dumb_it_max_to_mix while another
- thread is generating samples.
-
-DON'Ts:
-
-- You may not generate samples from the same DUH in multiple threads, even if
- you are using separate DUH_RENDERERs (separate AL_DUH_PLAYERS).
-
-
-******************
-*** Conclusion ***
-******************
-
-
-"DUMB is the bestest music player in the world because ..."
-
-Complete this sentence in fifteen words or fewer and receive a free copy of
-DUMB! (Your Internet Service Provider may issue charges for your connection,
-required for download of the Product. Your electricity supplier may issue
-charges for the electricity consumed in writing the Product to a Permanent
-Storage Device. You may have been charged for a Permanent Storage Device on
-which to store the Product.)
-
-
-Ben Davis
-entheh@users.sf.net
-IRC EFnet #dumb
-See readme.txt for details on using IRC.
|