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 "glsl/GrGLSLFragmentProcessor.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 domain()30 const GrTextureDomain& domain() const { return fDomain; } 31 32 /** 33 * Create a simple filter effect with custom bicubic coefficients and optional domain. 34 */ 35 static const GrFragmentProcessor* Create(GrTexture* tex, const SkScalar coefficients[16], 36 const SkRect* domain = nullptr) { 37 if (nullptr == domain) { 38 static const SkShader::TileMode kTileModes[] = { SkShader::kClamp_TileMode, 39 SkShader::kClamp_TileMode }; 40 return Create(tex, coefficients, GrCoordTransform::MakeDivByTextureWHMatrix(tex), 41 kTileModes); 42 } else { 43 return new GrBicubicEffect(tex, coefficients, 44 GrCoordTransform::MakeDivByTextureWHMatrix(tex), *domain); 45 } 46 } 47 48 /** 49 * Create a Mitchell filter effect with specified texture matrix and x/y tile modes. 50 */ Create(GrTexture * tex,const SkMatrix & matrix,const SkShader::TileMode tileModes[2])51 static const GrFragmentProcessor* Create(GrTexture* tex, const SkMatrix& matrix, 52 const SkShader::TileMode tileModes[2]) { 53 return Create(tex, gMitchellCoefficients, matrix, tileModes); 54 } 55 56 /** 57 * Create a filter effect with custom bicubic coefficients, the texture matrix, and the x/y 58 * tilemodes. 59 */ Create(GrTexture * tex,const SkScalar coefficients[16],const SkMatrix & matrix,const SkShader::TileMode tileModes[2])60 static const GrFragmentProcessor* Create(GrTexture* tex, const SkScalar coefficients[16], 61 const SkMatrix& matrix, 62 const SkShader::TileMode tileModes[2]) { 63 return new GrBicubicEffect(tex, coefficients, matrix, tileModes); 64 } 65 66 /** 67 * Create a Mitchell filter effect with a texture matrix and a domain. 68 */ Create(GrTexture * tex,const SkMatrix & matrix,const SkRect & domain)69 static const GrFragmentProcessor* Create(GrTexture* tex, const SkMatrix& matrix, 70 const SkRect& domain) { 71 return new GrBicubicEffect(tex, gMitchellCoefficients, matrix, domain); 72 } 73 74 /** 75 * Determines whether the bicubic effect should be used based on the transformation from the 76 * local coords to the device. Returns true if the bicubic effect should be used. filterMode 77 * is set to appropriate filtering mode to use regardless of the return result (e.g. when this 78 * returns false it may indicate that the best fallback is to use kMipMap, kBilerp, or 79 * kNearest). 80 */ 81 static bool ShouldUseBicubic(const SkMatrix& localCoordsToDevice, 82 GrTextureParams::FilterMode* filterMode); 83 84 private: 85 GrBicubicEffect(GrTexture*, const SkScalar coefficients[16], const SkMatrix &matrix, 86 const SkShader::TileMode tileModes[2]); 87 GrBicubicEffect(GrTexture*, const SkScalar coefficients[16], const SkMatrix &matrix, 88 const SkRect& domain); 89 90 GrGLSLFragmentProcessor* onCreateGLSLInstance() const override; 91 92 void onGetGLSLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override; 93 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