OLD | NEW |
(Empty) | |
| 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 #include "SkImageDecoder.h" |
| 14 |
| 15 class SkBitmap; |
| 16 |
| 17 class SkScaledBitmapSampler { |
| 18 public: |
| 19 SkScaledBitmapSampler(int origWidth, int origHeight, int cellSize); |
| 20 |
| 21 int scaledWidth() const { return fScaledWidth; } |
| 22 int scaledHeight() const { return fScaledHeight; } |
| 23 |
| 24 int srcY0() const { return fY0; } |
| 25 int srcDX() const { return fDX; } |
| 26 int srcDY() const { return fDY; } |
| 27 |
| 28 enum SrcConfig { |
| 29 kGray, // 1 byte per pixel |
| 30 kIndex, // 1 byte per pixel |
| 31 kRGB, // 3 bytes per pixel |
| 32 kRGBX, // 4 byes per pixel (ignore 4th) |
| 33 kRGBA, // 4 bytes per pixel |
| 34 kRGB_565 // 2 bytes per pixel |
| 35 }; |
| 36 |
| 37 struct Options { |
| 38 bool fDither; |
| 39 bool fPremultiplyAlpha; |
| 40 bool fSkipZeros; |
| 41 explicit Options(const SkImageDecoder &dec) |
| 42 : fDither(dec.getDitherImage()) |
| 43 , fPremultiplyAlpha(!dec.getRequireUnpremultipliedColors()) |
| 44 , fSkipZeros(dec.getSkipWritingZeroes()) |
| 45 { } |
| 46 }; |
| 47 |
| 48 // Given a dst bitmap (with pixels already allocated) and a src-config, |
| 49 // prepares iterator to process the src colors and write them into dst. |
| 50 // Returns false if the request cannot be fulfulled. |
| 51 bool begin(SkBitmap* dst, SrcConfig sc, const SkImageDecoder& decoder, |
| 52 const SkPMColor* = nullptr); |
| 53 bool begin(SkBitmap* dst, SrcConfig sc, const Options& opts, |
| 54 const SkPMColor* = nullptr); |
| 55 // call with row of src pixels, for y = 0...scaledHeight-1. |
| 56 // returns true if the row had non-opaque alpha in it |
| 57 bool next(const uint8_t* SK_RESTRICT src); |
| 58 |
| 59 // Like next(), but specifies the y value of the source row, so the |
| 60 // rows can come in any order. If the row is not part of the output |
| 61 // sample, it will be skipped. Only sampleInterlaced OR next should |
| 62 // be called for one SkScaledBitmapSampler. |
| 63 bool sampleInterlaced(const uint8_t* SK_RESTRICT src, int srcY); |
| 64 |
| 65 typedef bool (*RowProc)(void* SK_RESTRICT dstRow, |
| 66 const uint8_t* SK_RESTRICT src, |
| 67 int width, int deltaSrc, int y, |
| 68 const SkPMColor[]); |
| 69 |
| 70 private: |
| 71 int fScaledWidth; |
| 72 int fScaledHeight; |
| 73 |
| 74 int fX0; // first X coord to sample |
| 75 int fY0; // first Y coord (scanline) to sample |
| 76 int fDX; // step between X samples |
| 77 int fDY; // step between Y samples |
| 78 |
| 79 #ifdef SK_DEBUG |
| 80 // Keep track of whether the caller is using next or sampleInterlaced. |
| 81 // Only one can be used per sampler. |
| 82 enum SampleMode { |
| 83 kUninitialized_SampleMode, |
| 84 kConsecutive_SampleMode, |
| 85 kInterlaced_SampleMode, |
| 86 }; |
| 87 |
| 88 SampleMode fSampleMode; |
| 89 #endif |
| 90 |
| 91 // setup state |
| 92 char* fDstRow; // points into bitmap's pixels |
| 93 size_t fDstRowBytes; |
| 94 int fCurrY; // used for dithering |
| 95 int fSrcPixelSize; // 1, 3, 4 |
| 96 RowProc fRowProc; |
| 97 |
| 98 // optional reference to the src colors if the src is a palette model |
| 99 const SkPMColor* fCTable; |
| 100 |
| 101 #ifdef SK_DEBUG |
| 102 // Helper class allowing a test to have access to fRowProc. |
| 103 friend class RowProcTester; |
| 104 #endif |
| 105 }; |
| 106 |
| 107 #endif |
OLD | NEW |