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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 "SkColorTable.h"
#include "SkEncodedFormat.h"
#include "SkImageInfo.h"
#include "SkRefCnt.h"
#include "SkSwizzler.h"
#ifdef SKIA_PNG_PREFIXED
// this must proceed png.h
#include "pngprefix.h"
#endif
#include "png.h"
class SkScanlineDecoder;
class SkStream;
class SkPngCodec : public SkCodec {
public:
// Assumes IsPng was called and returned true.
static SkCodec* NewFromStream(SkStream*);
static bool IsPng(SkStream*);
protected:
Result onGetPixels(const SkImageInfo&, void*, size_t, const Options&, SkPMColor*, int*)
override;
SkEncodedFormat onGetEncodedFormat() const override { return kPNG_SkEncodedFormat; }
SkScanlineDecoder* onGetScanlineDecoder(const SkImageInfo& dstInfo, const Options& options,
SkPMColor ctable[], int* ctableCount) override;
bool onReallyHasAlpha() const override { return fReallyHasAlpha; }
private:
png_structp fPng_ptr;
png_infop 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;
SkSwizzler::SrcConfig fSrcConfig;
int fNumberPasses;
bool fReallyHasAlpha;
SkPngCodec(const SkImageInfo&, SkStream*, png_structp, png_infop);
~SkPngCodec();
// Helper to set up swizzler and color table. Also calls png_read_update_info.
Result initializeSwizzler(const SkImageInfo& requestedInfo, void* dst,
size_t rowBytes, const Options&, SkPMColor*, int* ctableCount);
// Calls rewindIfNeeded, and returns true if the decoder can continue.
bool handleRewind();
bool decodePalette(bool premultiply, int bitDepth, int* ctableCount);
void finish();
void destroyReadStruct();
friend class SkPngScanlineDecoder;
typedef SkCodec INHERITED;
};
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