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,uint32_t colorOrIndex,SkCodec::ZeroInitialized zeroInit)42     void fill(const SkImageInfo& info, void* dst, size_t rowBytes, uint32_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 private:
49 
50     /*
51      * Row procedure used for swizzle
52      */
53     typedef void (*RowProc)(void* dstRow, const uint8_t* srcRow, int width,
54             SkMasks* masks, uint32_t startX, uint32_t sampleX);
55 
56     SkMaskSwizzler(SkMasks* masks, RowProc proc, int subsetWidth, int srcOffset);
57 
58     int onSetSampleX(int) override;
59 
60     SkMasks*        fMasks;           // unowned
61     const RowProc   fRowProc;
62 
63     // FIXME: Can this class share more with SkSwizzler? These variables are all the same.
64     const int       fSubsetWidth;     // Width of the subset of source before any sampling.
65     int             fDstWidth;        // Width of dst, which may differ with sampling.
66     int             fSampleX;
67     int             fSrcOffset;
68     int             fX0;
69 };
70 
71 #endif
72