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/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkCodec.h"
#include "SkColorSpaceXform.h"
#include "SkColorTable.h"
#include "SkPngChunkReader.h"
#include "SkEncodedFormat.h"
#include "SkImageInfo.h"
#include "SkRefCnt.h"
#include "SkSwizzler.h"
class SkStream;
class SkPngCodec : public SkCodec {
public:
static bool IsPng(const char*, size_t);
// Assume IsPng was called and returned true.
static SkCodec* NewFromStream(SkStream*, SkPngChunkReader* = NULL);
virtual ~SkPngCodec();
protected:
// We hold the png_ptr and info_ptr as voidp to avoid having to include png.h
// or forward declare their types here. voidp auto-casts to the real pointer types.
struct voidp {
voidp(void* ptr) : fPtr(ptr) {}
template <typename T>
operator T*() const { return (T*)fPtr; }
explicit operator bool() const { return fPtr != nullptr; }
void* fPtr;
};
Result onGetPixels(const SkImageInfo&, void*, size_t, const Options&, SkPMColor*, int*, int*)
override;
SkEncodedFormat onGetEncodedFormat() const override { return kPNG_SkEncodedFormat; }
bool onRewind() override;
uint64_t onGetFillValue(const SkImageInfo&) const override;
// Helper to set up swizzler, color xforms, and color table. Also calls png_read_update_info.
bool initializeXforms(const SkImageInfo& dstInfo, const Options&, SkPMColor* colorPtr,
int* colorCount);
void initializeSwizzler(const SkImageInfo& dstInfo, const Options&);
SkSampler* getSampler(bool createIfNecessary) override;
void allocateStorage(const SkImageInfo& dstInfo);
void applyXformRow(void* dst, const void* src, SkColorType, SkAlphaType, int width);
virtual int readRows(const SkImageInfo& dstInfo, void* dst, size_t rowBytes, int count,
int startRow) = 0;
SkPngCodec(const SkEncodedInfo&, const SkImageInfo&, SkStream*, SkPngChunkReader*,
void* png_ptr, void* info_ptr, int, int);
SkAutoTUnref<SkPngChunkReader> fPngChunkReader;
voidp fPng_ptr;
voidp fInfo_ptr;
// These are stored here so they can be used both by normal decoding and scanline decoding.
SkAutoTUnref<SkColorTable> fColorTable; // May be unpremul.
SkAutoTDelete<SkSwizzler> fSwizzler;
std::unique_ptr<SkColorSpaceXform> fColorXform;
SkAutoTMalloc<uint8_t> fStorage;
uint8_t* fSwizzlerSrcRow;
uint32_t* fColorXformSrcRow;
size_t fSrcRowBytes;
const int fNumberPasses;
int fBitDepth;
private:
enum XformMode {
// Requires only a swizzle pass.
kSwizzleOnly_XformMode,
// Requires only a color xform pass.
kColorOnly_XformMode,
// Requires a swizzle and a color xform.
kSwizzleColor_XformMode,
};
bool createColorTable(const SkImageInfo& dstInfo, int* ctableCount);
void destroyReadStruct();
XformMode fXformMode;
typedef SkCodec INHERITED;
};
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