void GrGLBicubicEffect::emitCode(EmitArgs& args) { const GrBicubicEffect& bicubicEffect = args.fFp.cast<GrBicubicEffect>(); 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 GrGLSLShaderVar gCubicBlendArgs[] = { GrGLSLShaderVar("coefficients", kMat44f_GrSLType), GrGLSLShaderVar("t", kFloat_GrSLType), GrGLSLShaderVar("c0", kVec4f_GrSLType), GrGLSLShaderVar("c1", kVec4f_GrSLType), GrGLSLShaderVar("c2", kVec4f_GrSLType), GrGLSLShaderVar("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); // 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"); for (int y = 0; y < 4; ++y) { for (int x = 0; x < 4; ++x) { SkString coord; coord.printf("coord + %s * vec2(%d, %d)", imgInc, x - 1, y - 1); SkString sampleVar; sampleVar.printf("rowColors[%d]", x); fDomain.sampleTexture(fragBuilder, args.fUniformHandler, args.fGLSLCaps, bicubicEffect.domain(), sampleVar.c_str(), coord, 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); } SkString bicubicColor; bicubicColor.printf("%s(%s, f.y, s0, s1, s2, s3)", cubicBlendName.c_str(), coeff); if (colorSpaceHelper.getXformMatrix()) { SkString xformedColor; fragBuilder->appendColorGamutXform(&xformedColor, bicubicColor.c_str(), &colorSpaceHelper); bicubicColor.swap(xformedColor); } fragBuilder->codeAppendf("\t%s = %s;\n", args.fOutputColor, (GrGLSLExpr4(bicubicColor.c_str()) * GrGLSLExpr4(args.fInputColor)).c_str()); }