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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 "SkMasks.h"
11 #include "SkSampler.h"
12 #include "SkSwizzler.h"
13 #include "SkTypes.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      * Create a new swizzler
26      * @param masks Unowned pointer to helper class
27      */
28     static SkMaskSwizzler* CreateMaskSwizzler(const SkImageInfo& dstInfo,
29                                               const SkImageInfo& srcInfo,
30                                               SkMasks* masks,
31                                               uint32_t bitsPerPixel,
32                                               const SkCodec::Options& options);
33 
34     /*
35      * Swizzle a row
36      */
37     void swizzle(void* dst, const uint8_t* SK_RESTRICT src);
38 
39     /**
40      * Implement fill using a custom width.
41      */
fill(const SkImageInfo & info,void * dst,size_t rowBytes,uint64_t colorOrIndex,SkCodec::ZeroInitialized zeroInit)42     void fill(const SkImageInfo& info, void* dst, size_t rowBytes, uint64_t colorOrIndex,
43             SkCodec::ZeroInitialized zeroInit) override {
44         const SkImageInfo fillInfo = info.makeWH(fDstWidth, info.height());
45         SkSampler::Fill(fillInfo, dst, rowBytes, colorOrIndex, zeroInit);
46     }
47 
48     /**
49      *  Returns the byte offset at which we write to destination memory, taking
50      *  scaling, subsetting, and partial frames into account.
51      *  A similar function exists on SkSwizzler.
52      */
swizzleWidth()53     int swizzleWidth() const { return fDstWidth; }
54 
55 private:
56 
57     /*
58      * Row procedure used for swizzle
59      */
60     typedef void (*RowProc)(void* dstRow, const uint8_t* srcRow, int width,
61             SkMasks* masks, uint32_t startX, uint32_t sampleX);
62 
63     SkMaskSwizzler(SkMasks* masks, RowProc proc, int subsetWidth, int srcOffset);
64 
65     int onSetSampleX(int) override;
66 
67     SkMasks*        fMasks;           // unowned
68     const RowProc   fRowProc;
69 
70     // FIXME: Can this class share more with SkSwizzler? These variables are all the same.
71     const int       fSubsetWidth;     // Width of the subset of source before any sampling.
72     int             fDstWidth;        // Width of dst, which may differ with sampling.
73     int             fSampleX;
74     int             fSrcOffset;
75     int             fX0;
76 };
77 
78 #endif
79