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 "include/core/SkImageInfo.h" 11 #include "include/core/SkTypes.h" 12 #include "src/codec/SkBmpBaseCodec.h" 13 #include "src/codec/SkColorTable.h" 14 #include "src/codec/SkSwizzler.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 */ 20 class SkBmpStandardCodec : public SkBmpBaseCodec { 21 public: 22 23 /* 24 * Creates an instance of the decoder 25 * 26 * Called only by SkBmpCodec::MakeFromStream 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(SkEncodedInfo&& info, std::unique_ptr<SkStream> stream, 43 uint16_t bitsPerPixel, uint32_t numColors, uint32_t bytesPerColor, 44 uint32_t offset, SkCodec::SkScanlineOrder rowOrder, 45 bool isOpaque, bool inIco); 46 47 protected: 48 49 Result onGetPixels(const SkImageInfo& dstInfo, void* dst, 50 size_t dstRowBytes, const Options&, 51 int*) override; 52 onInIco()53 bool onInIco() const override { 54 return fInIco; 55 } 56 57 SkCodec::Result onPrepareToDecode(const SkImageInfo& dstInfo, 58 const SkCodec::Options& options) override; 59 getSampler(bool createIfNecessary)60 SkSampler* getSampler(bool createIfNecessary) override { 61 SkASSERT(fSwizzler); 62 return fSwizzler.get(); 63 } 64 65 private: 66 bool createColorTable(SkColorType colorType, SkAlphaType alphaType); 67 SkEncodedInfo swizzlerInfo() const; 68 void initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts); 69 70 int decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes, 71 const Options& opts) override; 72 73 /* 74 * @param stream This may be a pointer to the stream owned by the parent SkCodec 75 * or a sub-stream of the stream owned by the parent SkCodec. 76 * Either way, this stream is unowned. 77 */ 78 void decodeIcoMask(SkStream* stream, const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes); 79 80 sk_sp<SkColorTable> fColorTable; 81 // fNumColors is the number specified in the header, or 0 if not present in the header. 82 const uint32_t fNumColors; 83 const uint32_t fBytesPerColor; 84 const uint32_t fOffset; 85 std::unique_ptr<SkSwizzler> fSwizzler; 86 const bool fIsOpaque; 87 const bool fInIco; 88 const size_t fAndMaskRowBytes; // only used for fInIco decodes 89 90 using INHERITED = SkBmpBaseCodec; 91 }; 92 #endif // SkBmpStandardCodec_DEFINED 93