1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/images/SkScaledBitmapSampler.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,94 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2011 Google Inc.
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +#ifndef SkScaledBitmapSampler_DEFINED
1.12 +#define SkScaledBitmapSampler_DEFINED
1.13 +
1.14 +#include "SkTypes.h"
1.15 +#include "SkColor.h"
1.16 +#include "SkImageDecoder.h"
1.17 +
1.18 +class SkBitmap;
1.19 +
1.20 +class SkScaledBitmapSampler {
1.21 +public:
1.22 + SkScaledBitmapSampler(int origWidth, int origHeight, int cellSize);
1.23 +
1.24 + int scaledWidth() const { return fScaledWidth; }
1.25 + int scaledHeight() const { return fScaledHeight; }
1.26 +
1.27 + int srcY0() const { return fY0; }
1.28 + int srcDX() const { return fDX; }
1.29 + int srcDY() const { return fDY; }
1.30 +
1.31 + enum SrcConfig {
1.32 + kGray, // 1 byte per pixel
1.33 + kIndex, // 1 byte per pixel
1.34 + kRGB, // 3 bytes per pixel
1.35 + kRGBX, // 4 byes per pixel (ignore 4th)
1.36 + kRGBA, // 4 bytes per pixel
1.37 + kRGB_565 // 2 bytes per pixel
1.38 + };
1.39 +
1.40 + // Given a dst bitmap (with pixels already allocated) and a src-config,
1.41 + // prepares iterator to process the src colors and write them into dst.
1.42 + // Returns false if the request cannot be fulfulled.
1.43 + bool begin(SkBitmap* dst, SrcConfig sc, const SkImageDecoder& decoder,
1.44 + const SkPMColor* = NULL);
1.45 + // call with row of src pixels, for y = 0...scaledHeight-1.
1.46 + // returns true if the row had non-opaque alpha in it
1.47 + bool next(const uint8_t* SK_RESTRICT src);
1.48 +
1.49 + // Like next(), but specifies the y value of the source row, so the
1.50 + // rows can come in any order. If the row is not part of the output
1.51 + // sample, it will be skipped. Only sampleInterlaced OR next should
1.52 + // be called for one SkScaledBitmapSampler.
1.53 + bool sampleInterlaced(const uint8_t* SK_RESTRICT src, int srcY);
1.54 +
1.55 + typedef bool (*RowProc)(void* SK_RESTRICT dstRow,
1.56 + const uint8_t* SK_RESTRICT src,
1.57 + int width, int deltaSrc, int y,
1.58 + const SkPMColor[]);
1.59 +
1.60 +private:
1.61 + int fScaledWidth;
1.62 + int fScaledHeight;
1.63 +
1.64 + int fX0; // first X coord to sample
1.65 + int fY0; // first Y coord (scanline) to sample
1.66 + int fDX; // step between X samples
1.67 + int fDY; // step between Y samples
1.68 +
1.69 +#ifdef SK_DEBUG
1.70 + // Keep track of whether the caller is using next or sampleInterlaced.
1.71 + // Only one can be used per sampler.
1.72 + enum SampleMode {
1.73 + kUninitialized_SampleMode,
1.74 + kConsecutive_SampleMode,
1.75 + kInterlaced_SampleMode,
1.76 + };
1.77 +
1.78 + SampleMode fSampleMode;
1.79 +#endif
1.80 +
1.81 + // setup state
1.82 + char* fDstRow; // points into bitmap's pixels
1.83 + size_t fDstRowBytes;
1.84 + int fCurrY; // used for dithering
1.85 + int fSrcPixelSize; // 1, 3, 4
1.86 + RowProc fRowProc;
1.87 +
1.88 + // optional reference to the src colors if the src is a palette model
1.89 + const SkPMColor* fCTable;
1.90 +
1.91 +#ifdef SK_DEBUG
1.92 + // Helper class allowing a test to have access to fRowProc.
1.93 + friend class RowProcTester;
1.94 +#endif
1.95 +};
1.96 +
1.97 +#endif
