1 #ifndef SkScaledBitmapSampler_DEFINED 2 #define SkScaledBitmapSampler_DEFINED 3 4 #include "SkTypes.h" 5 #include "SkColor.h" 6 7 class SkBitmap; 8 9 class SkScaledBitmapSampler { 10 public: 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 36 private: 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 62
