1 #include "GrBicubicEffect.h" 2 3 #define DS(x) SkDoubleToScalar(x) 4 5 const SkScalar GrBicubicEffect::gMitchellCoefficients[16] = { 6 DS( 1.0 / 18.0), DS(-9.0 / 18.0), DS( 15.0 / 18.0), DS( -7.0 / 18.0), 7 DS(16.0 / 18.0), DS( 0.0 / 18.0), DS(-36.0 / 18.0), DS( 21.0 / 18.0), 8 DS( 1.0 / 18.0), DS( 9.0 / 18.0), DS( 27.0 / 18.0), DS(-21.0 / 18.0), 9 DS( 0.0 / 18.0), DS( 0.0 / 18.0), DS( -6.0 / 18.0), DS( 7.0 / 18.0), 10 }; 11 12 13 class GrGLBicubicEffect : public GrGLEffect { 14 public: 15 GrGLBicubicEffect(const GrBackendEffectFactory& factory, 16 const GrDrawEffect&); 17 virtual void emitCode(GrGLShaderBuilder*, 18 const GrDrawEffect&, 19 EffectKey, 20 const char* outputColor, 21 const char* inputColor, 22 const TransformedCoordsArray&, 23 const TextureSamplerArray&) SK_OVERRIDE; 24 25 virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE; 26 27 private: 28 typedef GrGLUniformManager::UniformHandle UniformHandle; 29 30 UniformHandle fCoefficientsUni; 31 UniformHandle fImageIncrementUni; 32 33 typedef GrGLEffect INHERITED; 34 }; 35 36 GrGLBicubicEffect::GrGLBicubicEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&) 37 : INHERITED(factory) { 38 } 39 40 void GrGLBicubicEffect::emitCode(GrGLShaderBuilder* builder, 41 const GrDrawEffect&, 42 EffectKey key, 43 const char* outputColor, 44 const char* inputColor, 45 const TransformedCoordsArray& coords, 46 const TextureSamplerArray& samplers) { 47 sk_ignore_unused_variable(inputColor); 48 49 SkString coords2D = builder->ensureFSCoords2D(coords, 0); 50 fCoefficientsUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility, 51 kMat44f_GrSLType, "Coefficients"); 52 fImageIncrementUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility, 53 kVec2f_GrSLType, "ImageIncrement"); 54 55 const char* imgInc = builder->getUniformCStr(fImageIncrementUni); 56 const char* coeff = builder->getUniformCStr(fCoefficientsUni); 57 58 SkString cubicBlendName; 59 60 static const GrGLShaderVar gCubicBlendArgs[] = { 61 GrGLShaderVar("coefficients", kMat44f_GrSLType), 62 GrGLShaderVar("t", kFloat_GrSLType), 63 GrGLShaderVar("c0", kVec4f_GrSLType), 64 GrGLShaderVar("c1", kVec4f_GrSLType), 65 GrGLShaderVar("c2", kVec4f_GrSLType), 66 GrGLShaderVar("c3", kVec4f_GrSLType), 67 }; 68 builder->fsEmitFunction(kVec4f_GrSLType, 69 "cubicBlend", 70 SK_ARRAY_COUNT(gCubicBlendArgs), 71 gCubicBlendArgs, 72 "\tvec4 ts = vec4(1.0, t, t * t, t * t * t);\n" 73 "\tvec4 c = coefficients * ts;\n" 74 "\treturn c.x * c0 + c.y * c1 + c.z * c2 + c.w * c3;\n", 75 &cubicBlendName); 76 builder->fsCodeAppendf("\tvec2 coord = %s - %s * vec2(0.5);\n", coords2D.c_str(), imgInc); 77 // We unnormalize the coord in order to determine our fractional offset (f) within the texel 78 // We then snap coord to a texel center and renormalize. The snap prevents cases where the 79 // starting coords are near a texel boundary and accumulations of imgInc would cause us to skip/ 80 // double hit a texel. 81 builder->fsCodeAppendf("\tcoord /= %s;\n", imgInc); 82 builder->fsCodeAppend("\tvec2 f = fract(coord);\n"); 83 builder->fsCodeAppendf("\tcoord = (coord - f + vec2(0.5)) * %s;\n", imgInc); 84 for (int y = 0; y < 4; ++y) { 85 for (int x = 0; x < 4; ++x) { 86 SkString coord; 87 coord.printf("coord + %s * vec2(%d, %d)", imgInc, x - 1, y - 1); 88 builder->fsCodeAppendf("\tvec4 s%d%d = ", x, y); 89 builder->fsAppendTextureLookup(samplers[0], coord.c_str()); 90 builder->fsCodeAppend(";\n"); 91 } 92 builder->fsCodeAppendf("\tvec4 s%d = %s(%s, f.x, s0%d, s1%d, s2%d, s3%d);\n", y, cubicBlendName.c_str(), coeff, y, y, y, y); 93 } 94 builder->fsCodeAppendf("\t%s = %s(%s, f.y, s0, s1, s2, s3);\n", outputColor, cubicBlendName.c_str(), coeff); 95 } 96 97 void GrGLBicubicEffect::setData(const GrGLUniformManager& uman, 98 const GrDrawEffect& drawEffect) { 99 const GrBicubicEffect& effect = drawEffect.castEffect<GrBicubicEffect>(); 100 GrTexture& texture = *effect.texture(0); 101 float imageIncrement[2]; 102 imageIncrement[0] = 1.0f / texture.width(); 103 imageIncrement[1] = 1.0f / texture.height(); 104 uman.set2fv(fImageIncrementUni, 1, imageIncrement); 105 uman.setMatrix4f(fCoefficientsUni, effect.coefficients()); 106 } 107 108 GrBicubicEffect::GrBicubicEffect(GrTexture* texture, 109 const SkScalar coefficients[16], 110 const SkMatrix &matrix, 111 const SkShader::TileMode tileModes[2]) 112 : INHERITED(texture, matrix, GrTextureParams(tileModes, GrTextureParams::kNone_FilterMode)) { 113 for (int y = 0; y < 4; y++) { 114 for (int x = 0; x < 4; x++) { 115 // Convert from row-major scalars to column-major floats. 116 fCoefficients[x * 4 + y] = SkScalarToFloat(coefficients[y * 4 + x]); 117 } 118 } 119 this->setWillNotUseInputColor(); 120 } 121 122 GrBicubicEffect::~GrBicubicEffect() { 123 } 124 125 const GrBackendEffectFactory& GrBicubicEffect::getFactory() const { 126 return GrTBackendEffectFactory<GrBicubicEffect>::getInstance(); 127 } 128 129 bool GrBicubicEffect::onIsEqual(const GrEffect& sBase) const { 130 const GrBicubicEffect& s = CastEffect<GrBicubicEffect>(sBase); 131 return this->textureAccess(0) == s.textureAccess(0) && 132 !memcmp(fCoefficients, s.coefficients(), 16); 133 } 134 135 void GrBicubicEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const { 136 // FIXME: Perhaps we can do better. 137 *validFlags = 0; 138 return; 139 } 140 141 GR_DEFINE_EFFECT_TEST(GrBicubicEffect); 142 143 GrEffectRef* GrBicubicEffect::TestCreate(SkRandom* random, 144 GrContext* context, 145 const GrDrawTargetCaps&, 146 GrTexture* textures[]) { 147 int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx : 148 GrEffectUnitTest::kAlphaTextureIdx; 149 SkScalar coefficients[16]; 150 for (int i = 0; i < 16; i++) { 151 coefficients[i] = random->nextSScalar1(); 152 } 153 return GrBicubicEffect::Create(textures[texIdx], coefficients); 154 } 155
