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 scaledWidth()13 int scaledWidth() const { return fScaledWidth; } scaledHeight()14 int scaledHeight() const { return fScaledHeight; } 15 srcY0()16 int srcY0() const { return fY0; } srcDY()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 kRGB_565 // 2 bytes per pixel 26 }; 27 28 // Given a dst bitmap (with pixels already allocated) and a src-config, 29 // prepares iterator to process the src colors and write them into dst. 30 // Returns false if the request cannot be fulfulled. 31 bool begin(SkBitmap* dst, SrcConfig sc, bool doDither, 32 const SkPMColor* = NULL); 33 // call with row of src pixels, for y = 0...scaledHeight-1. 34 // returns true if the row had non-opaque alpha in it 35 bool next(const uint8_t* SK_RESTRICT src); 36 37 private: 38 int fScaledWidth; 39 int fScaledHeight; 40 41 int fX0; // first X coord to sample 42 int fY0; // first Y coord (scanline) to sample 43 int fDX; // step between X samples 44 int fDY; // step between Y samples 45 46 typedef bool (*RowProc)(void* SK_RESTRICT dstRow, 47 const uint8_t* SK_RESTRICT src, 48 int width, int deltaSrc, int y, 49 const SkPMColor[]); 50 51 // setup state 52 char* fDstRow; // points into bitmap's pixels 53 int fDstRowBytes; 54 int fCurrY; // used for dithering 55 int fSrcPixelSize; // 1, 3, 4 56 RowProc fRowProc; 57 58 // optional reference to the src colors if the src is a palette model 59 const SkPMColor* fCTable; 60 }; 61 62 #endif 63