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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 SkMaskSwizzler_DEFINED
8 #define SkMaskSwizzler_DEFINED
9 
10 #include "include/core/SkTypes.h"
11 #include "src/codec/SkMasks.h"
12 #include "src/codec/SkSampler.h"
13 #include "src/codec/SkSwizzler.h"
14 
15 /*
16  *
17  * Used to swizzle images whose pixel components are extracted by bit masks
18  * Currently only used by bmp
19  *
20  */
21 class SkMaskSwizzler : public SkSampler {
22 public:
23 
24     /*
25      * @param masks Unowned pointer to helper class
26      */
27     static SkMaskSwizzler* CreateMaskSwizzler(const SkImageInfo& dstInfo,
28                                               bool srcIsOpaque,
29                                               SkMasks* masks,
30                                               uint32_t bitsPerPixel,
31                                               const SkCodec::Options& options);
32 
33     /*
34      * Swizzle a row
35      */
36     void swizzle(void* dst, const uint8_t* SK_RESTRICT src);
37 
fillWidth()38     int fillWidth() const override {
39         return fDstWidth;
40     }
41 
42     /**
43      *  Returns the byte offset at which we write to destination memory, taking
44      *  scaling, subsetting, and partial frames into account.
45      *  A similar function exists on SkSwizzler.
46      */
swizzleWidth()47     int swizzleWidth() const { return fDstWidth; }
48 
49 private:
50 
51     /*
52      * Row procedure used for swizzle
53      */
54     typedef void (*RowProc)(void* dstRow, const uint8_t* srcRow, int width,
55             SkMasks* masks, uint32_t startX, uint32_t sampleX);
56 
57     SkMaskSwizzler(SkMasks* masks, RowProc proc, int subsetWidth, int srcOffset);
58 
59     int onSetSampleX(int) override;
60 
61     SkMasks*        fMasks;           // unowned
62     const RowProc   fRowProc;
63 
64     // FIXME: Can this class share more with SkSwizzler? These variables are all the same.
65     const int       fSubsetWidth;     // Width of the subset of source before any sampling.
66     int             fDstWidth;        // Width of dst, which may differ with sampling.
67     int             fSampleX;
68     int             fSrcOffset;
69     int             fX0;
70 };
71 
72 #endif
73