diff --git a/src/gpu/effects/GrBicubicEffect.cpp b/src/gpu/effects/GrBicubicEffect.cpp index de93aaacc6..9d8e728efc 100644 --- a/src/gpu/effects/GrBicubicEffect.cpp +++ b/src/gpu/effects/GrBicubicEffect.cpp @@ -13,32 +13,6 @@ #include "glsl/GrGLSLUniformHandler.h" #include "../private/GrGLSL.h" -/* - * Filter weights come from Don Mitchell & Arun Netravali's 'Reconstruction Filters in Computer - * Graphics', ACM SIGGRAPH Computer Graphics 22, 4 (Aug. 1988). - * ACM DL: http://dl.acm.org/citation.cfm?id=378514 - * Free : http://www.cs.utexas.edu/users/fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf - * - * The authors define a family of cubic filters with two free parameters (B and C): - * - * { (12 - 9B - 6C)|x|^3 + (-18 + 12B + 6C)|x|^2 + (6 - 2B) if |x| < 1 - * k(x) = 1/6 { (-B - 6C)|x|^3 + (6B + 30C)|x|^2 + (-12B - 48C)|x| + (8B + 24C) if 1 <= |x| < 2 - * { 0 otherwise - * - * Various well-known cubic splines can be generated, and the authors select (1/3, 1/3) as their - * favorite overall spline - this is now commonly known as the Mitchell filter, and is the source - * of the specific weights below. - * - * These weights are in column-major order (ie this matrix is transposed from what you'd expect), - * so we can upload them directly via setMatrix4f. - */ -static constexpr float kMitchellCoefficients[16] = { - 1.0f / 18.0f, 16.0f / 18.0f, 1.0f / 18.0f, 0.0f / 18.0f, - -9.0f / 18.0f, 0.0f / 18.0f, 9.0f / 18.0f, 0.0f / 18.0f, - 15.0f / 18.0f, -36.0f / 18.0f, 27.0f / 18.0f, -6.0f / 18.0f, - -7.0f / 18.0f, 21.0f / 18.0f, -21.0f / 18.0f, 7.0f / 18.0f, -}; - class GrGLBicubicEffect : public GrGLSLFragmentProcessor { public: void emitCode(EmitArgs&) override; @@ -56,7 +30,6 @@ protected: private: typedef GrGLSLProgramDataManager::UniformHandle UniformHandle; - UniformHandle fCoefficientsUni; UniformHandle fImageIncrementUni; UniformHandle fColorSpaceXformUni; GrTextureDomain::GLDomain fDomain; @@ -68,48 +41,52 @@ void GrGLBicubicEffect::emitCode(EmitArgs& args) { const GrBicubicEffect& bicubicEffect = args.fFp.cast(); GrGLSLUniformHandler* uniformHandler = args.fUniformHandler; - fCoefficientsUni = uniformHandler->addUniform(kFragment_GrShaderFlag, - kMat44f_GrSLType, kDefault_GrSLPrecision, - "Coefficients"); fImageIncrementUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kVec2f_GrSLType, kDefault_GrSLPrecision, "ImageIncrement"); const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni); - const char* coeff = uniformHandler->getUniformCStr(fCoefficientsUni); GrGLSLColorSpaceXformHelper colorSpaceHelper(uniformHandler, bicubicEffect.colorSpaceXform(), &fColorSpaceXformUni); - SkString cubicBlendName; - - static const GrShaderVar gCubicBlendArgs[] = { - GrShaderVar("coefficients", kMat44f_GrSLType), - GrShaderVar("t", kFloat_GrSLType), - GrShaderVar("c0", kVec4f_GrSLType), - GrShaderVar("c1", kVec4f_GrSLType), - GrShaderVar("c2", kVec4f_GrSLType), - GrShaderVar("c3", kVec4f_GrSLType), - }; GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder; SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]); - fragBuilder->emitFunction(kVec4f_GrSLType, - "cubicBlend", - SK_ARRAY_COUNT(gCubicBlendArgs), - gCubicBlendArgs, - "\tvec4 ts = vec4(1.0, t, t * t, t * t * t);\n" - "\tvec4 c = coefficients * ts;\n" - "\treturn c.x * c0 + c.y * c1 + c.z * c2 + c.w * c3;\n", - &cubicBlendName); - fragBuilder->codeAppendf("\tvec2 coord = %s - %s * vec2(0.5);\n", coords2D.c_str(), imgInc); + + /* + * Filter weights come from Don Mitchell & Arun Netravali's 'Reconstruction Filters in Computer + * Graphics', ACM SIGGRAPH Computer Graphics 22, 4 (Aug. 1988). + * ACM DL: http://dl.acm.org/citation.cfm?id=378514 + * Free : http://www.cs.utexas.edu/users/fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf + * + * The authors define a family of cubic filters with two free parameters (B and C): + * + * { (12 - 9B - 6C)|x|^3 + (-18 + 12B + 6C)|x|^2 + (6 - 2B) if |x| < 1 + * k(x) = 1/6 { (-B - 6C)|x|^3 + (6B + 30C)|x|^2 + (-12B - 48C)|x| + (8B + 24C) if 1 <= |x| < 2 + * { 0 otherwise + * + * Various well-known cubic splines can be generated, and the authors select (1/3, 1/3) as their + * favorite overall spline - this is now commonly known as the Mitchell filter, and is the + * source of the specific weights below. + * + * This is GLSL, so the matrix is column-major (transposed from standard matrix notation). + */ + fragBuilder->codeAppend("mat4 kMitchellCoefficients = mat4(" + " 1.0 / 18.0, 16.0 / 18.0, 1.0 / 18.0, 0.0 / 18.0," + "-9.0 / 18.0, 0.0 / 18.0, 9.0 / 18.0, 0.0 / 18.0," + "15.0 / 18.0, -36.0 / 18.0, 27.0 / 18.0, -6.0 / 18.0," + "-7.0 / 18.0, 21.0 / 18.0, -21.0 / 18.0, 7.0 / 18.0);"); + fragBuilder->codeAppendf("vec2 coord = %s - %s * vec2(0.5);", coords2D.c_str(), imgInc); // We unnormalize the coord in order to determine our fractional offset (f) within the texel // We then snap coord to a texel center and renormalize. The snap prevents cases where the // starting coords are near a texel boundary and accumulations of imgInc would cause us to skip/ // double hit a texel. - fragBuilder->codeAppendf("\tcoord /= %s;\n", imgInc); - fragBuilder->codeAppend("\tvec2 f = fract(coord);\n"); - fragBuilder->codeAppendf("\tcoord = (coord - f + vec2(0.5)) * %s;\n", imgInc); - fragBuilder->codeAppend("\tvec4 rowColors[4];\n"); + fragBuilder->codeAppendf("coord /= %s;", imgInc); + fragBuilder->codeAppend("vec2 f = fract(coord);"); + fragBuilder->codeAppendf("coord = (coord - f + vec2(0.5)) * %s;", imgInc); + fragBuilder->codeAppend("vec4 wx = kMitchellCoefficients * vec4(1.0, f.x, f.x * f.x, f.x * f.x * f.x);"); + fragBuilder->codeAppend("vec4 wy = kMitchellCoefficients * vec4(1.0, f.y, f.y * f.y, f.y * f.y * f.y);"); + fragBuilder->codeAppend("vec4 rowColors[4];"); for (int y = 0; y < 4; ++y) { for (int x = 0; x < 4; ++x) { SkString coord; @@ -125,17 +102,16 @@ void GrGLBicubicEffect::emitCode(EmitArgs& args) { args.fTexSamplers[0]); } fragBuilder->codeAppendf( - "\tvec4 s%d = %s(%s, f.x, rowColors[0], rowColors[1], rowColors[2], rowColors[3]);\n", - y, cubicBlendName.c_str(), coeff); + "vec4 s%d = wx.x * rowColors[0] + wx.y * rowColors[1] + wx.z * rowColors[2] + wx.w * rowColors[3];", + y); } - SkString bicubicColor; - bicubicColor.printf("%s(%s, f.y, s0, s1, s2, s3)", cubicBlendName.c_str(), coeff); + SkString bicubicColor("(wy.x * s0 + wy.y * s1 + wy.z * s2 + wy.w * s3)"); if (colorSpaceHelper.getXformMatrix()) { SkString xformedColor; fragBuilder->appendColorGamutXform(&xformedColor, bicubicColor.c_str(), &colorSpaceHelper); bicubicColor.swap(xformedColor); } - fragBuilder->codeAppendf("\t%s = %s;\n", + fragBuilder->codeAppendf("%s = %s;", args.fOutputColor, (GrGLSLExpr4(bicubicColor.c_str()) * GrGLSLExpr4(args.fInputColor)).c_str()); } @@ -148,7 +124,6 @@ void GrGLBicubicEffect::onSetData(const GrGLSLProgramDataManager& pdman, imageIncrement[0] = 1.0f / texture->width(); imageIncrement[1] = 1.0f / texture->height(); pdman.set2fv(fImageIncrementUni, 1, imageIncrement); - pdman.setMatrix4f(fCoefficientsUni, kMitchellCoefficients); fDomain.setData(pdman, bicubicEffect.domain(), texture->origin()); if (SkToBool(bicubicEffect.colorSpaceXform())) { pdman.setSkMatrix44(fColorSpaceXformUni, bicubicEffect.colorSpaceXform()->srcToDst());