/* * Copyright 2012 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #ifndef SkGradientShaderPriv_DEFINED #define SkGradientShaderPriv_DEFINED #include "SkGradientShader.h" #include "SkClampRange.h" #include "SkColorPriv.h" #include "SkFlattenableBuffers.h" #include "SkMallocPixelRef.h" #include "SkUnitMapper.h" #include "SkUtils.h" #include "SkTemplates.h" #include "SkBitmapCache.h" #include "SkShader.h" #ifndef SK_DISABLE_DITHER_32BIT_GRADIENT #define USE_DITHER_32BIT_GRADIENT #endif static void sk_memset32_dither(uint32_t dst[], uint32_t v0, uint32_t v1, int count) { if (count > 0) { if (v0 == v1) { sk_memset32(dst, v0, count); } else { int pairs = count >> 1; for (int i = 0; i < pairs; i++) { *dst++ = v0; *dst++ = v1; } if (count & 1) { *dst = v0; } } } } // Clamp static SkFixed clamp_tileproc(SkFixed x) { return SkClampMax(x, 0xFFFF); } // Repeat static SkFixed repeat_tileproc(SkFixed x) { return x & 0xFFFF; } // Mirror // Visual Studio 2010 (MSC_VER=1600) optimizes bit-shift code incorrectly. // See http://code.google.com/p/skia/issues/detail?id=472 #if defined(_MSC_VER) && (_MSC_VER >= 1600) #pragma optimize("", off) #endif static inline SkFixed mirror_tileproc(SkFixed x) { int s = x << 15 >> 31; return (x ^ s) & 0xFFFF; } #if defined(_MSC_VER) && (_MSC_VER >= 1600) #pragma optimize("", on) #endif /////////////////////////////////////////////////////////////////////////////// typedef SkFixed (*TileProc)(SkFixed); /////////////////////////////////////////////////////////////////////////////// static const TileProc gTileProcs[] = { clamp_tileproc, repeat_tileproc, mirror_tileproc }; /////////////////////////////////////////////////////////////////////////////// class SkGradientShaderBase : public SkShader { public: SkGradientShaderBase(const SkColor colors[], const SkScalar pos[], int colorCount, SkShader::TileMode mode, SkUnitMapper* mapper); virtual ~SkGradientShaderBase(); // overrides virtual bool setContext(const SkBitmap&, const SkPaint&, const SkMatrix&) SK_OVERRIDE; virtual uint32_t getFlags() SK_OVERRIDE { return fFlags; } virtual bool isOpaque() const SK_OVERRIDE; void getGradientTableBitmap(SkBitmap*) const; enum { /// Seems like enough for visual accuracy. TODO: if pos[] deserves /// it, use a larger cache. kCache16Bits = 8, kGradient16Length = (1 << kCache16Bits), /// Each cache gets 1 extra entry at the end so we don't have to /// test for end-of-cache in lerps. This is also the value used /// to stride *writes* into the dither cache; it must not be zero. /// Total space for a cache is 2x kCache16Count entries: one /// regular cache, one for dithering. kCache16Count = kGradient16Length + 1, kCache16Shift = 16 - kCache16Bits, kSqrt16Shift = 8 - kCache16Bits, /// Seems like enough for visual accuracy. TODO: if pos[] deserves /// it, use a larger cache. kCache32Bits = 8, kGradient32Length = (1 << kCache32Bits), /// Each cache gets 1 extra entry at the end so we don't have to /// test for end-of-cache in lerps. This is also the value used /// to stride *writes* into the dither cache; it must not be zero. /// Total space for a cache is 2x kCache32Count entries: one /// regular cache, one for dithering. kCache32Count = kGradient32Length + 1, kCache32Shift = 16 - kCache32Bits, kSqrt32Shift = 8 - kCache32Bits, /// This value is used to *read* the dither cache; it may be 0 /// if dithering is disabled. #ifdef USE_DITHER_32BIT_GRADIENT kDitherStride32 = kCache32Count, #else kDitherStride32 = 0, #endif kDitherStride16 = kCache16Count, kLerpRemainderMask32 = (1 << (16 - kCache32Bits)) - 1 }; protected: SkGradientShaderBase(SkFlattenableReadBuffer& ); virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE; SkUnitMapper* fMapper; SkMatrix fPtsToUnit; // set by subclass SkMatrix fDstToIndex; SkMatrix::MapXYProc fDstToIndexProc; TileMode fTileMode; TileProc fTileProc; int fColorCount; uint8_t fDstToIndexClass; uint8_t fFlags; struct Rec { SkFixed fPos; // 0...1 uint32_t fScale; // (1 << 24) / range }; Rec* fRecs; const uint16_t* getCache16() const; const SkPMColor* getCache32() const; void commonAsAGradient(GradientInfo*) const; private: enum { kColorStorageCount = 4, // more than this many colors, and we'll use sk_malloc for the space kStorageSize = kColorStorageCount * (sizeof(SkColor) + sizeof(Rec)) }; SkColor fStorage[(kStorageSize + 3) >> 2]; SkColor* fOrigColors; // original colors, before modulation by paint in setContext bool fColorsAreOpaque; mutable uint16_t* fCache16; // working ptr. If this is NULL, we need to recompute the cache values mutable SkPMColor* fCache32; // working ptr. If this is NULL, we need to recompute the cache values mutable uint16_t* fCache16Storage; // storage for fCache16, allocated on demand mutable SkMallocPixelRef* fCache32PixelRef; mutable unsigned fCacheAlpha; // the alpha value we used when we computed the cache. larger than 8bits so we can store uninitialized value static void Build16bitCache(uint16_t[], SkColor c0, SkColor c1, int count); static void Build32bitCache(SkPMColor[], SkColor c0, SkColor c1, int count, U8CPU alpha); void setCacheAlpha(U8CPU alpha) const; void initCommon(); typedef SkShader INHERITED; }; /////////////////////////////////////////////////////////////////////////////// #if SK_SUPPORT_GPU #include "gl/GrGLEffect.h" class GrSamplerState; class GrProgramStageFactory; /* * The intepretation of the texture matrix depends on the sample mode. The * texture matrix is applied both when the texture coordinates are explicit * and when vertex positions are used as texture coordinates. In the latter * case the texture matrix is applied to the pre-view-matrix position * values. * * Normal SampleMode * The post-matrix texture coordinates are in normalize space with (0,0) at * the top-left and (1,1) at the bottom right. * RadialGradient * The matrix specifies the radial gradient parameters. * (0,0) in the post-matrix space is center of the radial gradient. * Radial2Gradient * Matrix transforms to space where first circle is centered at the * origin. The second circle will be centered (x, 0) where x may be * 0 and is provided by setRadial2Params. The post-matrix space is * normalized such that 1 is the second radius - first radius. * SweepGradient * The angle from the origin of texture coordinates in post-matrix space * determines the gradient value. */ class GrTextureStripAtlas; // Base class for Gr gradient effects class GrGradientEffect : public GrEffect { public: GrGradientEffect(GrContext* ctx, const SkGradientShaderBase& shader, SkShader::TileMode tileMode); virtual ~GrGradientEffect(); virtual const GrTextureAccess& textureAccess(int index) const SK_OVERRIDE; bool useAtlas() const { return SkToBool(-1 != fRow); } GrScalar getYCoord() const { return fYCoord; }; virtual bool isEqual(const GrEffect& effect) const SK_OVERRIDE { const GrGradientEffect& s = static_cast(effect); return INHERITED::isEqual(effect) && this->useAtlas() == s.useAtlas() && fYCoord == s.getYCoord(); } protected: /** Populates a pair of arrays with colors and stop info to construct a random gradient. The function decides whether stop values should be used or not. The return value indicates the number of colors, which will be capped by kMaxRandomGradientColors. colors should be sized to be at least kMaxRandomGradientColors. stops is a pointer to an array of at least size kMaxRandomGradientColors. It may be updated to NULL, indicating that NULL should be passed to the gradient factory rather than the array. */ static const int kMaxRandomGradientColors = 4; static int RandomGradientParams(SkRandom* r, SkColor colors[kMaxRandomGradientColors], SkScalar** stops, SkShader::TileMode* tm); private: GrTextureAccess fTextureAccess; GrScalar fYCoord; GrTextureStripAtlas* fAtlas; int fRow; typedef GrEffect INHERITED; }; /////////////////////////////////////////////////////////////////////////////// // Base class for GL gradient effects class GrGLGradientStage : public GrGLLegacyProgramStage { public: GrGLGradientStage(const GrProgramStageFactory& factory); virtual ~GrGLGradientStage(); virtual void setupVariables(GrGLShaderBuilder* builder) SK_OVERRIDE; virtual void setData(const GrGLUniformManager&, const GrEffect&) SK_OVERRIDE; // emit code that gets a fragment's color from an expression for t; for now // this always uses the texture, but for simpler cases we'll be able to lerp void emitColorLookup(GrGLShaderBuilder* builder, const char* gradientTValue, const char* outputColor, const char* inputColor, const GrGLShaderBuilder::TextureSampler&); private: GrScalar fCachedYCoord; GrGLUniformManager::UniformHandle fFSYUni; typedef GrGLLegacyProgramStage INHERITED; }; #endif #endif