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 */
20class SkBmpStandardCodec : public SkBmpBaseCodec {
21public:
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
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 SkSampler* getSampler(bool createIfNecessary) override {
61 SkASSERT(fSwizzler);
62 return fSwizzler.get();
63 }
64
65private:
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 typedef SkBmpBaseCodec INHERITED;
91};
92#endif // SkBmpStandardCodec_DEFINED
93