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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 "SkBmpCodec.h"
#include "SkColorTable.h"
#include "SkImageInfo.h"
#include "SkSwizzler.h"
#include "SkTypes.h"
/*
* This class implements the decoding for bmp images that use "standard" modes,
* which essentially means they do not contain bit masks or RLE codes.
*/
class SkBmpStandardCodec : public SkBmpCodec {
public:
/*
* Creates an instance of the decoder
*
* Called only by SkBmpCodec::NewFromStream
* There should be no other callers despite this being public
*
* @param srcInfo contains the source width and height
* @param stream the stream of encoded image data
* @param bitsPerPixel the number of bits used to store each pixel
* @param numColors the number of colors in the color table
* @param bytesPerColor the number of bytes in the stream used to represent
each color in the color table
* @param offset the offset of the image pixel data from the end of the
* headers
* @param rowOrder indicates whether rows are ordered top-down or bottom-up
* @param isOpaque indicates if the bmp itself is opaque (before applying
* the icp mask, if there is one)
* @param inIco indicates if the bmp is embedded in an ico file
*/
SkBmpStandardCodec(const SkImageInfo& srcInfo, SkStream* stream,
uint16_t bitsPerPixel, uint32_t numColors, uint32_t bytesPerColor,
uint32_t offset, SkCodec::SkScanlineOrder rowOrder, bool isOpaque,
bool inIco);
protected:
Result onGetPixels(const SkImageInfo& dstInfo, void* dst,
size_t dstRowBytes, const Options&, SkPMColor*,
int*, int*) override;
bool onInIco() const override {
return fInIco;
}
SkCodec::Result prepareToDecode(const SkImageInfo& dstInfo,
const SkCodec::Options& options, SkPMColor inputColorPtr[],
int* inputColorCount) override;
uint32_t onGetFillValue(SkColorType) const override;
SkSampler* getSampler(bool createIfNecessary) override {
SkASSERT(fSwizzler);
return fSwizzler;
}
private:
/*
* Creates the color table
* Sets colorCount to the new color count if it is non-nullptr
*/
bool createColorTable(SkAlphaType alphaType, int* colorCount);
void initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts);
int decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
const Options& opts) override;
/*
* @param stream This may be a pointer to the stream owned by the parent SkCodec
* or a sub-stream of the stream owned by the parent SkCodec.
* Either way, this stream is unowned.
*/
void decodeIcoMask(SkStream* stream, const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes);
SkAutoTUnref<SkColorTable> fColorTable; // owned
// fNumColors is the number specified in the header, or 0 if not present in the header.
const uint32_t fNumColors;
const uint32_t fBytesPerColor;
const uint32_t fOffset;
SkAutoTDelete<SkSwizzler> fSwizzler;
SkAutoTDeleteArray<uint8_t> fSrcBuffer;
const bool fIsOpaque;
const bool fInIco;
const size_t fAndMaskRowBytes; // only used for fInIco decodes
typedef SkBmpCodec INHERITED;
};
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