/src/compiler/android/jni/ftk/SkScaledBitmapSampler.h

 1#ifndef SkScaledBitmapSampler_DEFINED
 2#define SkScaledBitmapSampler_DEFINED
 3
 4#include "SkTypes.h"
 5#include "SkColor.h"
 6
 7class SkBitmap;
 8
 9class SkScaledBitmapSampler {
10public:
11    SkScaledBitmapSampler(int origWidth, int origHeight, int cellSize);
12    
13    int scaledWidth() const { return fScaledWidth; }
14    int scaledHeight() const { return fScaledHeight; }
15    
16    int srcY0() const { return fY0; }
17    int srcDY() const { return fDY; }
18
19    enum SrcConfig {
20        kGray,  // 1 byte per pixel
21        kIndex, // 1 byte per pixel
22        kRGB,   // 3 bytes per pixel
23        kRGBX,  // 4 byes per pixel (ignore 4th)
24        kRGBA   // 4 bytes per pixel
25    };
26
27    // Given a dst bitmap (with pixels already allocated) and a src-config,
28    // prepares iterator to process the src colors and write them into dst.
29    // Returns false if the request cannot be fulfulled.
30    bool begin(SkBitmap* dst, SrcConfig sc, bool doDither,
31               const SkPMColor* = NULL);
32    // call with row of src pixels, for y = 0...scaledHeight-1.
33    // returns true if the row had non-opaque alpha in it
34    bool next(const uint8_t* SK_RESTRICT src);
35
36private:
37    int fScaledWidth;
38    int fScaledHeight;
39
40    int fX0;    // first X coord to sample
41    int fY0;    // first Y coord (scanline) to sample
42    int fDX;    // step between X samples
43    int fDY;    // step between Y samples
44
45    typedef bool (*RowProc)(void* SK_RESTRICT dstRow,
46                            const uint8_t* SK_RESTRICT src,
47                            int width, int deltaSrc, int y,
48                            const SkPMColor[]);
49
50    // setup state
51    char*   fDstRow; // points into bitmap's pixels
52    int     fDstRowBytes;
53    int     fCurrY; // used for dithering
54    int     fSrcPixelSize;  // 1, 3, 4    
55    RowProc fRowProc;
56
57    // optional reference to the src colors if the src is a palette model
58    const SkPMColor* fCTable;
59};
60
61#endif