| /* |
| * Copyright 2015 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| #ifndef SkPngCodec_DEFINED |
| #define SkPngCodec_DEFINED |
| |
| #include "include/codec/SkCodec.h" |
| #include "include/core/SkEncodedImageFormat.h" |
| #include "include/core/SkRefCnt.h" |
| #include "include/private/SkTemplates.h" |
| |
| #include <cstddef> |
| #include <cstdint> |
| #include <memory> |
| |
| class SkColorTable; |
| class SkPngChunkReader; |
| class SkSampler; |
| class SkStream; |
| class SkSwizzler; |
| struct SkEncodedInfo; |
| struct SkImageInfo; |
| |
| class SkPngCodec : public SkCodec { |
| public: |
| static bool IsPng(const void*, size_t); |
| |
| // Assume IsPng was called and returned true. |
| static std::unique_ptr<SkCodec> MakeFromStream(std::unique_ptr<SkStream>, Result*, |
| SkPngChunkReader* = nullptr); |
| |
| // FIXME (scroggo): Temporarily needed by AutoCleanPng. |
| void setIdatLength(size_t len) { fIdatLength = len; } |
| |
| ~SkPngCodec() override; |
| |
| 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; |
| }; |
| |
| SkPngCodec(SkEncodedInfo&&, std::unique_ptr<SkStream>, SkPngChunkReader*, |
| void* png_ptr, void* info_ptr, int bitDepth); |
| |
| Result onGetPixels(const SkImageInfo&, void*, size_t, const Options&, int*) |
| override; |
| SkEncodedImageFormat onGetEncodedFormat() const override { return SkEncodedImageFormat::kPNG; } |
| bool onRewind() override; |
| |
| SkSampler* getSampler(bool createIfNecessary) override; |
| void applyXformRow(void* dst, const void* src); |
| |
| voidp png_ptr() { return fPng_ptr; } |
| voidp info_ptr() { return fInfo_ptr; } |
| |
| SkSwizzler* swizzler() { return fSwizzler.get(); } |
| |
| // Initialize variables used by applyXformRow. |
| void initializeXformParams(); |
| |
| /** |
| * Pass available input to libpng to process it. |
| * |
| * libpng will call any relevant callbacks installed. This will continue decoding |
| * until it reaches the end of the file, or until a callback tells libpng to stop. |
| */ |
| bool processData(); |
| |
| Result onStartIncrementalDecode(const SkImageInfo& dstInfo, void* pixels, size_t rowBytes, |
| const SkCodec::Options&) override; |
| Result onIncrementalDecode(int*) override; |
| |
| sk_sp<SkPngChunkReader> fPngChunkReader; |
| voidp fPng_ptr; |
| voidp fInfo_ptr; |
| |
| // These are stored here so they can be used both by normal decoding and scanline decoding. |
| sk_sp<SkColorTable> fColorTable; // May be unpremul. |
| std::unique_ptr<SkSwizzler> fSwizzler; |
| SkAutoTMalloc<uint8_t> fStorage; |
| void* fColorXformSrcRow; |
| const 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); |
| // Helper to set up swizzler, color xforms, and color table. Also calls png_read_update_info. |
| SkCodec::Result initializeXforms(const SkImageInfo& dstInfo, const Options&); |
| void initializeSwizzler(const SkImageInfo& dstInfo, const Options&, bool skipFormatConversion); |
| void allocateStorage(const SkImageInfo& dstInfo); |
| void destroyReadStruct(); |
| |
| virtual Result decodeAllRows(void* dst, size_t rowBytes, int* rowsDecoded) = 0; |
| virtual void setRange(int firstRow, int lastRow, void* dst, size_t rowBytes) = 0; |
| virtual Result decode(int* rowsDecoded) = 0; |
| |
| XformMode fXformMode; |
| int fXformWidth; |
| |
| size_t fIdatLength; |
| bool fDecodedIdat; |
| |
| using INHERITED = SkCodec; |
| }; |
| #endif // SkPngCodec_DEFINED |