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 8 #include "SkBmpCodec.h" 9 #include "SkColorTable.h" 10 #include "SkImageInfo.h" 11 #include "SkSwizzler.h" 12 #include "SkTypes.h" 13 14 /* 15 * This class implements the decoding for bmp images that use "standard" modes, 16 * which essentially means they do not contain bit masks or RLE codes. 17 */ 18 class SkBmpStandardCodec : public SkBmpCodec { 19 public: 20 21 /* 22 * Creates an instance of the decoder 23 * 24 * Called only by SkBmpCodec::NewFromStream 25 * There should be no other callers despite this being public 26 * 27 * @param srcInfo contains the source width and height 28 * @param stream the stream of encoded image data 29 * @param bitsPerPixel the number of bits used to store each pixel 30 * @param numColors the number of colors in the color table 31 * @param bytesPerColor the number of bytes in the stream used to represent 32 each color in the color table 33 * @param offset the offset of the image pixel data from the end of the 34 * headers 35 * @param rowOrder indicates whether rows are ordered top-down or bottom-up 36 * @param isOpaque indicates if the bmp itself is opaque (before applying 37 * the icp mask, if there is one) 38 * @param inIco indicates if the bmp is embedded in an ico file 39 */ 40 SkBmpStandardCodec(const SkImageInfo& srcInfo, SkStream* stream, 41 uint16_t bitsPerPixel, uint32_t numColors, uint32_t bytesPerColor, 42 uint32_t offset, SkCodec::SkScanlineOrder rowOrder, bool isOpaque, 43 bool inIco); 44 45 protected: 46 47 Result onGetPixels(const SkImageInfo& dstInfo, void* dst, 48 size_t dstRowBytes, const Options&, SkPMColor*, 49 int*, int*) override; 50 51 bool onInIco() const override { 52 return fInIco; 53 } 54 55 SkCodec::Result prepareToDecode(const SkImageInfo& dstInfo, 56 const SkCodec::Options& options, SkPMColor inputColorPtr[], 57 int* inputColorCount) override; 58 59 60 uint32_t onGetFillValue(SkColorType) const override; 61 62 SkSampler* getSampler(bool createIfNecessary) override { 63 SkASSERT(fSwizzler); 64 return fSwizzler; 65 } 66 67 private: 68 69 /* 70 * Creates the color table 71 * Sets colorCount to the new color count if it is non-nullptr 72 */ 73 bool createColorTable(SkAlphaType alphaType, int* colorCount); 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 SkAutoTUnref<SkColorTable> fColorTable; // owned 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 SkAutoTDelete<SkSwizzler> fSwizzler; 93 SkAutoTDeleteArray<uint8_t> fSrcBuffer; 94 const bool fIsOpaque; 95 const bool fInIco; 96 const size_t fAndMaskRowBytes; // only used for fInIco decodes 97 98 typedef SkBmpCodec INHERITED; 99 }; 100
