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 #ifndef SkBmpMaskCodec_DEFINED
9 #define SkBmpMaskCodec_DEFINED
10 
11 #include "SkBmpBaseCodec.h"
12 #include "SkImageInfo.h"
13 #include "SkMaskSwizzler.h"
14 #include "SkTypes.h"
15 
16 /*
17  * This class implements the decoding for bmp images using bit masks
18  */
19 class SkBmpMaskCodec : public SkBmpBaseCodec {
20 public:
21 
22     /*
23      * Creates an instance of the decoder
24      *
25      * Called only by SkBmpCodec::MakeFromStream
26      * There should be no other callers despite this being public
27      *
28      * @param info contains properties of the encoded data
29      * @param stream the stream of encoded image data
30      * @param bitsPerPixel the number of bits used to store each pixel
31      * @param masks color masks for certain bmp formats
32      * @param rowOrder indicates whether rows are ordered top-down or bottom-up
33      */
34     SkBmpMaskCodec(SkEncodedInfo&& info, std::unique_ptr<SkStream>,
35             uint16_t bitsPerPixel, SkMasks* masks,
36             SkCodec::SkScanlineOrder rowOrder);
37 
38 protected:
39 
40     Result onGetPixels(const SkImageInfo& dstInfo, void* dst,
41                        size_t dstRowBytes, const Options&,
42                        int*) override;
43 
44     SkCodec::Result onPrepareToDecode(const SkImageInfo& dstInfo,
45             const SkCodec::Options& options) override;
46 
47 private:
48 
49     SkSampler* getSampler(bool createIfNecessary) override {
50         SkASSERT(fMaskSwizzler);
51         return fMaskSwizzler.get();
52     }
53 
54     int decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
55             const Options& opts) override;
56 
57     std::unique_ptr<SkMasks>        fMasks;
58     std::unique_ptr<SkMaskSwizzler> fMaskSwizzler;
59 
60     typedef SkBmpBaseCodec INHERITED;
61 };
62 #endif  // SkBmpMaskCodec_DEFINED
63