SkBmpStandardCodec.h revision 571b30f6117eede6d64cd2b924dc1f6aaa59e70e
1/* 2 * Copyright 2015 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7#ifndef SkBmpStandardCodec_DEFINED 8#define SkBmpStandardCodec_DEFINED 9 10#include "SkBmpBaseCodec.h" 11#include "SkColorTable.h" 12#include "SkImageInfo.h" 13#include "SkSwizzler.h" 14#include "SkTypes.h" 15 16/* 17 * This class implements the decoding for bmp images that use "standard" modes, 18 * which essentially means they do not contain bit masks or RLE codes. 19 */ 20class SkBmpStandardCodec : public SkBmpBaseCodec { 21public: 22 23 /* 24 * Creates an instance of the decoder 25 * 26 * Called only by SkBmpCodec::NewFromStream 27 * There should be no other callers despite this being public 28 * 29 * @param info contains properties of the encoded data 30 * @param stream the stream of encoded image data 31 * @param bitsPerPixel the number of bits used to store each pixel 32 * @param numColors the number of colors in the color table 33 * @param bytesPerColor the number of bytes in the stream used to represent 34 each color in the color table 35 * @param offset the offset of the image pixel data from the end of the 36 * headers 37 * @param rowOrder indicates whether rows are ordered top-down or bottom-up 38 * @param isOpaque indicates if the bmp itself is opaque (before applying 39 * the icp mask, if there is one) 40 * @param inIco indicates if the bmp is embedded in an ico file 41 */ 42 SkBmpStandardCodec(int width, int height, const SkEncodedInfo& info, SkStream* stream, 43 uint16_t bitsPerPixel, uint32_t numColors, uint32_t bytesPerColor, 44 uint32_t offset, SkCodec::SkScanlineOrder rowOrder, bool isOpaque, 45 bool inIco); 46 47protected: 48 49 Result onGetPixels(const SkImageInfo& dstInfo, void* dst, 50 size_t dstRowBytes, const Options&, 51 int*) override; 52 53 bool onInIco() const override { 54 return fInIco; 55 } 56 57 SkCodec::Result onPrepareToDecode(const SkImageInfo& dstInfo, 58 const SkCodec::Options& options) override; 59 60 61 uint64_t onGetFillValue(const SkImageInfo&) const override; 62 63 SkSampler* getSampler(bool createIfNecessary) override { 64 SkASSERT(fSwizzler); 65 return fSwizzler.get(); 66 } 67 68private: 69 70 /* 71 * Creates the color table 72 */ 73 bool createColorTable(SkColorType colorType, SkAlphaType alphaType); 74 75 void initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts); 76 77 int decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes, 78 const Options& opts) override; 79 80 /* 81 * @param stream This may be a pointer to the stream owned by the parent SkCodec 82 * or a sub-stream of the stream owned by the parent SkCodec. 83 * Either way, this stream is unowned. 84 */ 85 void decodeIcoMask(SkStream* stream, const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes); 86 87 sk_sp<SkColorTable> fColorTable; 88 // fNumColors is the number specified in the header, or 0 if not present in the header. 89 const uint32_t fNumColors; 90 const uint32_t fBytesPerColor; 91 const uint32_t fOffset; 92 std::unique_ptr<SkSwizzler> fSwizzler; 93 const bool fIsOpaque; 94 const bool fInIco; 95 const size_t fAndMaskRowBytes; // only used for fInIco decodes 96 97 typedef SkBmpBaseCodec INHERITED; 98}; 99#endif // SkBmpStandardCodec_DEFINED 100