1 /* 2 * Copyright 2013 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef GrBicubicTextureEffect_DEFINED 9 #define GrBicubicTextureEffect_DEFINED 10 11 #include "GrSingleTextureEffect.h" 12 #include "GrTextureDomain.h" 13 #include "gl/GrGLProcessor.h" 14 15 class GrGLBicubicEffect; 16 class GrInvariantOutput; 17 18 class GrBicubicEffect : public GrSingleTextureEffect { 19 public: 20 enum { 21 kFilterTexelPad = 2, // Given a src rect in texels to be filtered, this number of 22 // surrounding texels are needed by the kernel in x and y. 23 }; 24 virtual ~GrBicubicEffect(); 25 coefficients()26 const float* coefficients() const { return fCoefficients; } 27 name()28 const char* name() const override { return "Bicubic"; } 29 30 void getGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override; 31 32 GrGLFragmentProcessor* createGLInstance() const override; 33 domain()34 const GrTextureDomain& domain() const { return fDomain; } 35 36 /** 37 * Create a simple filter effect with custom bicubic coefficients and optional domain. 38 */ 39 static GrFragmentProcessor* Create(GrTexture* tex, const SkScalar coefficients[16], 40 const SkRect* domain = NULL) { 41 if (NULL == domain) { 42 static const SkShader::TileMode kTileModes[] = { SkShader::kClamp_TileMode, 43 SkShader::kClamp_TileMode }; 44 return Create(tex, coefficients, GrCoordTransform::MakeDivByTextureWHMatrix(tex), 45 kTileModes); 46 } else { 47 return SkNEW_ARGS(GrBicubicEffect, (tex, coefficients, 48 GrCoordTransform::MakeDivByTextureWHMatrix(tex), 49 *domain)); 50 } 51 } 52 53 /** 54 * Create a Mitchell filter effect with specified texture matrix and x/y tile modes. 55 */ Create(GrTexture * tex,const SkMatrix & matrix,SkShader::TileMode tileModes[2])56 static GrFragmentProcessor* Create(GrTexture* tex, const SkMatrix& matrix, 57 SkShader::TileMode tileModes[2]) { 58 return Create(tex, gMitchellCoefficients, matrix, tileModes); 59 } 60 61 /** 62 * Create a filter effect with custom bicubic coefficients, the texture matrix, and the x/y 63 * tilemodes. 64 */ Create(GrTexture * tex,const SkScalar coefficients[16],const SkMatrix & matrix,const SkShader::TileMode tileModes[2])65 static GrFragmentProcessor* Create(GrTexture* tex, const SkScalar coefficients[16], 66 const SkMatrix& matrix, 67 const SkShader::TileMode tileModes[2]) { 68 return SkNEW_ARGS(GrBicubicEffect, (tex, coefficients, matrix, tileModes)); 69 } 70 71 /** 72 * Create a Mitchell filter effect with a texture matrix and a domain. 73 */ Create(GrTexture * tex,const SkMatrix & matrix,const SkRect & domain)74 static GrFragmentProcessor* Create(GrTexture* tex, const SkMatrix& matrix, 75 const SkRect& domain) { 76 return SkNEW_ARGS(GrBicubicEffect, (tex, gMitchellCoefficients, matrix, domain)); 77 } 78 79 /** 80 * Determines whether the bicubic effect should be used based on the transformation from the 81 * local coords to the device. Returns true if the bicubic effect should be used. filterMode 82 * is set to appropriate filtering mode to use regardless of the return result (e.g. when this 83 * returns false it may indicate that the best fallback is to use kMipMap, kBilerp, or 84 * kNearest). 85 */ 86 static bool ShouldUseBicubic(const SkMatrix& localCoordsToDevice, 87 GrTextureParams::FilterMode* filterMode); 88 89 private: 90 GrBicubicEffect(GrTexture*, const SkScalar coefficients[16], 91 const SkMatrix &matrix, const SkShader::TileMode tileModes[2]); 92 GrBicubicEffect(GrTexture*, const SkScalar coefficients[16], 93 const SkMatrix &matrix, const SkRect& domain); 94 bool onIsEqual(const GrFragmentProcessor&) const override; 95 96 void onComputeInvariantOutput(GrInvariantOutput* inout) const override; 97 98 float fCoefficients[16]; 99 GrTextureDomain fDomain; 100 101 GR_DECLARE_FRAGMENT_PROCESSOR_TEST; 102 103 static const SkScalar gMitchellCoefficients[16]; 104 105 typedef GrSingleTextureEffect INHERITED; 106 }; 107 108 #endif 109