1 2 /* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 #ifndef SkScaledBitmapSampler_DEFINED 9 #define SkScaledBitmapSampler_DEFINED 10 11 #include "SkTypes.h" 12 #include "SkColor.h" 13 14 class SkBitmap; 15 16 class SkScaledBitmapSampler { 17 public: 18 SkScaledBitmapSampler(int origWidth, int origHeight, int cellSize); 19 scaledWidth()20 int scaledWidth() const { return fScaledWidth; } scaledHeight()21 int scaledHeight() const { return fScaledHeight; } 22 srcY0()23 int srcY0() const { return fY0; } srcDY()24 int srcDY() const { return fDY; } 25 26 enum SrcConfig { 27 kGray, // 1 byte per pixel 28 kIndex, // 1 byte per pixel 29 kRGB, // 3 bytes per pixel 30 kRGBX, // 4 byes per pixel (ignore 4th) 31 kRGBA, // 4 bytes per pixel 32 kRGB_565 // 2 bytes per pixel 33 }; 34 35 // Given a dst bitmap (with pixels already allocated) and a src-config, 36 // prepares iterator to process the src colors and write them into dst. 37 // Returns false if the request cannot be fulfulled. 38 bool begin(SkBitmap* dst, SrcConfig sc, bool doDither, 39 const SkPMColor* = NULL); 40 // call with row of src pixels, for y = 0...scaledHeight-1. 41 // returns true if the row had non-opaque alpha in it 42 bool next(const uint8_t* SK_RESTRICT src); 43 44 private: 45 int fScaledWidth; 46 int fScaledHeight; 47 48 int fX0; // first X coord to sample 49 int fY0; // first Y coord (scanline) to sample 50 int fDX; // step between X samples 51 int fDY; // step between Y samples 52 53 typedef bool (*RowProc)(void* SK_RESTRICT dstRow, 54 const uint8_t* SK_RESTRICT src, 55 int width, int deltaSrc, int y, 56 const SkPMColor[]); 57 58 // setup state 59 char* fDstRow; // points into bitmap's pixels 60 int fDstRowBytes; 61 int fCurrY; // used for dithering 62 int fSrcPixelSize; // 1, 3, 4 63 RowProc fRowProc; 64 65 // optional reference to the src colors if the src is a palette model 66 const SkPMColor* fCTable; 67 }; 68 69 #endif 70