C++ GrGLFragmentBuilder::codeAppend方法代码示例

void GLCircleEffect::emitCode(EmitArgs& args) {
    const CircleEffect& ce = args.fFp.cast<CircleEffect>();
    const char *circleName;
    // The circle uniform is (center.x, center.y, radius + 0.5, 1 / (radius + 0.5)) for regular
    // fills and (..., radius - 0.5, 1 / (radius - 0.5)) for inverse fills.
    fCircleUniform = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                         kVec4f_GrSLType, kDefault_GrSLPrecision,
                                         "circle",
                                         &circleName);

    GrGLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
    const char* fragmentPos = fsBuilder->fragmentPosition();

    SkASSERT(kHairlineAA_GrProcessorEdgeType != ce.getEdgeType());
    // TODO: Right now the distance to circle caclulation is performed in a space normalized to the
    // radius and then denormalized. This is to prevent overflow on devices that have a "real"
    // mediump. It'd be nice to only to this on mediump devices but we currently don't have the
    // caps here.
    if (GrProcessorEdgeTypeIsInverseFill(ce.getEdgeType())) {
        fsBuilder->codeAppendf("\t\tfloat d = (length((%s.xy - %s.xy) * %s.w) - 1.0) * %s.z;\n",
                                circleName, fragmentPos, circleName, circleName);
    } else {
        fsBuilder->codeAppendf("\t\tfloat d = (1.0 - length((%s.xy - %s.xy) *  %s.w)) * %s.z;\n",
                               circleName, fragmentPos, circleName, circleName);
    }
    if (GrProcessorEdgeTypeIsAA(ce.getEdgeType())) {
        fsBuilder->codeAppend("\t\td = clamp(d, 0.0, 1.0);\n");
    } else {
        fsBuilder->codeAppend("\t\td = d > 0.5 ? 1.0 : 0.0;\n");
    }

    fsBuilder->codeAppendf("\t\t%s = %s;\n", args.fOutputColor,
                           (GrGLSLExpr4(args.fInputColor) * GrGLSLExpr1("d")).c_str());
}

    virtual void emitCode(GrGLFPBuilder* builder,
                          const GrFragmentProcessor&,
                          const char* outputColor,
                          const char* inputColor,
                          const TransformedCoordsArray& coords,
                          const TextureSamplerArray& samplers) override {
        // Using highp for GLES here in order to avoid some precision issues on specific GPUs.
        GrGLShaderVar tmpVar("tmpColor", kVec4f_GrSLType, 0, kHigh_GrSLPrecision);
        SkString tmpDecl;
        tmpVar.appendDecl(builder->ctxInfo(), &tmpDecl);

        GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();

        fsBuilder->codeAppendf("%s;", tmpDecl.c_str());

        fsBuilder->codeAppendf("%s = ", tmpVar.c_str());
        fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType());
        fsBuilder->codeAppend(";");

        if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
            SkASSERT(fSwapRedAndBlue);
            fsBuilder->codeAppendf("%s = %s.bgra;", outputColor, tmpVar.c_str());
        } else {
            const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
            switch (fPMConversion) {
                case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
                    fsBuilder->codeAppendf(
                        "%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);",
                        tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
                    break;
                case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
                    // Add a compensation(0.001) here to avoid the side effect of the floor operation.
                    // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
                    // is less than the integer value converted from  %s.r by 1 when the %s.r is
                    // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
                    fsBuilder->codeAppendf(
                        "%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);",
                        tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
                    break;
                case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
                    fsBuilder->codeAppendf(
                        "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
                        tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
                    break;
                case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
                    fsBuilder->codeAppendf(
                        "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
                        tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
                    break;
                default:
                    SkFAIL("Unknown conversion op.");
                    break;
            }
            fsBuilder->codeAppendf("%s = %s;", outputColor, tmpVar.c_str());
        }
        SkString modulate;
        GrGLSLMulVarBy4f(&modulate, outputColor, inputColor);
        fsBuilder->codeAppend(modulate.c_str());
    }

void GrGLBicubicEffect::emitCode(EmitArgs& args) {
    const GrTextureDomain& domain = args.fFp.cast<GrBicubicEffect>().domain();

    fCoefficientsUni = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                           kMat44f_GrSLType, kDefault_GrSLPrecision,
                                           "Coefficients");
    fImageIncrementUni = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                             kVec2f_GrSLType, kDefault_GrSLPrecision,
                                             "ImageIncrement");

    const char* imgInc = args.fBuilder->getUniformCStr(fImageIncrementUni);
    const char* coeff = args.fBuilder->getUniformCStr(fCoefficientsUni);

    SkString cubicBlendName;

    static const GrGLShaderVar gCubicBlendArgs[] = {
        GrGLShaderVar("coefficients",  kMat44f_GrSLType),
        GrGLShaderVar("t",             kFloat_GrSLType),
        GrGLShaderVar("c0",            kVec4f_GrSLType),
        GrGLShaderVar("c1",            kVec4f_GrSLType),
        GrGLShaderVar("c2",            kVec4f_GrSLType),
        GrGLShaderVar("c3",            kVec4f_GrSLType),
    };
    GrGLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
    SkString coords2D = fsBuilder->ensureFSCoords2D(args.fCoords, 0);
    fsBuilder->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);
    fsBuilder->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.
    fsBuilder->codeAppendf("\tcoord /= %s;\n", imgInc);
    fsBuilder->codeAppend("\tvec2 f = fract(coord);\n");
    fsBuilder->codeAppendf("\tcoord = (coord - f + vec2(0.5)) * %s;\n", imgInc);
    fsBuilder->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(fsBuilder, domain, sampleVar.c_str(), coord, args.fSamplers[0]);
        }
        fsBuilder->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);
    fsBuilder->codeAppendf("\t%s = %s;\n", args.fOutputColor,(GrGLSLExpr4(bicubicColor.c_str()) *
                           GrGLSLExpr4(args.fInputColor)).c_str());
}

 void emitCode(EmitArgs& args) override {
     GrGLFragmentBuilder* fpb = args.fBuilder->getFragmentShaderBuilder();
     fpb->codeAppendf("vec2 c = %s;", fpb->ensureFSCoords2D(args.fCoords, 0).c_str());
     fpb->codeAppend("vec2 r = mod(c, vec2(20.0));");
     fpb->codeAppend("vec4 color = vec4(0.5*sin(c.x / 15.0) + 0.5,"
                                         "0.5*cos((c.x + c.y) / 15.0) + 0.5,"
                                         "(r.x + r.y) / 20.0,"
                                         "distance(r, vec2(15.0)) / 20.0 + 0.2);");
     fpb->codeAppendf("color.rgb *= color.a;"
                         "%s = color * %s;",
                         args.fOutputColor, GrGLSLExpr4(args.fInputColor).c_str());
 }

    void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
        const GrBitmapTextGeoProc& cte = args.fGP.cast<GrBitmapTextGeoProc>();

        GrGLGPBuilder* pb = args.fPB;
        GrGLVertexBuilder* vsBuilder = pb->getVertexShaderBuilder();

        // emit attributes
        vsBuilder->emitAttributes(cte);

        GrGLVertToFrag v(kVec2f_GrSLType);
        pb->addVarying("TextureCoords", &v);
        // this is only used with text, so our texture bounds always match the glyph atlas
        if (cte.maskFormat() == kA8_GrMaskFormat) {
            vsBuilder->codeAppendf("%s = vec2(" GR_FONT_ATLAS_A8_RECIP_WIDTH ", "
                                   GR_FONT_ATLAS_RECIP_HEIGHT ")*%s;", v.vsOut(),
                                   cte.inTextureCoords()->fName);
        } else {
            vsBuilder->codeAppendf("%s = vec2(" GR_FONT_ATLAS_RECIP_WIDTH ", "
                                   GR_FONT_ATLAS_RECIP_HEIGHT ")*%s;", v.vsOut(),
                                   cte.inTextureCoords()->fName);
        }

        // Setup pass through color
        if (!cte.colorIgnored()) {
            if (cte.hasVertexColor()) {
                pb->addPassThroughAttribute(cte.inColor(), args.fOutputColor);
            } else {
                this->setupUniformColor(pb, args.fOutputColor, &fColorUniform);
            }
        }

        // Setup position
        this->setupPosition(pb, gpArgs, cte.inPosition()->fName);

        // emit transforms
        this->emitTransforms(args.fPB, gpArgs->fPositionVar, cte.inPosition()->fName,
                             cte.localMatrix(), args.fTransformsIn, args.fTransformsOut);

        GrGLFragmentBuilder* fsBuilder = pb->getFragmentShaderBuilder();
        if (cte.maskFormat() == kARGB_GrMaskFormat) {
            fsBuilder->codeAppendf("%s = ", args.fOutputColor);
            fsBuilder->appendTextureLookupAndModulate(args.fOutputColor,
                                                      args.fSamplers[0],
                                                      v.fsIn(),
                                                      kVec2f_GrSLType);
            fsBuilder->codeAppend(";");
            fsBuilder->codeAppendf("%s = vec4(1);", args.fOutputCoverage);
        } else {
            fsBuilder->codeAppendf("%s = ", args.fOutputCoverage);
            fsBuilder->appendTextureLookup(args.fSamplers[0], v.fsIn(), kVec2f_GrSLType);
            fsBuilder->codeAppend(";");
        }
    }

 void emitCode(GrGLFPBuilder* builder,
                 const GrFragmentProcessor& fp,
                 const char* outputColor,
                 const char* inputColor,
                 const TransformedCoordsArray& coords,
                 const TextureSamplerArray& samplers) {
     GrGLFragmentBuilder* fpb = builder->getFragmentShaderBuilder();
     fpb->codeAppendf("vec2 c = %s;", fpb->ensureFSCoords2D(coords, 0).c_str());
     fpb->codeAppend("vec2 r = mod(c, vec2(20.0));");
     fpb->codeAppend("vec4 color = vec4(0.5*sin(c.x / 15.0) + 0.5,"
                                         "0.5*cos((c.x + c.y) / 15.0) + 0.5,"
                                         "(r.x + r.y) / 20.0,"
                                         "distance(r, vec2(15.0)) / 20.0 + 0.2);");
     fpb->codeAppendf("color.rgb *= color.a;"
                         "%s = color * %s;",
                         outputColor, GrGLSLExpr4(inputColor).c_str());
 }

 virtual void emitCode(EmitArgs& args) override {
     GrGLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
     fsBuilder->codeAppendf("\t%s = ", args.fOutputColor);
     fsBuilder->appendTextureLookupAndModulate(args.fInputColor,
                                               args.fSamplers[0],
                                               args.fCoords[0].c_str(),
                                               args.fCoords[0].getType());
     fsBuilder->codeAppend(";\n");
 }

void GrColorCubeEffect::GLProcessor::emitCode(GrGLFPBuilder* builder,
                                              const GrFragmentProcessor&,
                                              const char* outputColor,
                                              const char* inputColor,
                                              const TransformedCoordsArray& coords,
                                              const TextureSamplerArray& samplers) {
    if (NULL == inputColor) {
        inputColor = "vec4(1)";
    }

    fColorCubeSizeUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                            kFloat_GrSLType, kDefault_GrSLPrecision,
                                            "Size");
    const char* colorCubeSizeUni = builder->getUniformCStr(fColorCubeSizeUni);
    fColorCubeInvSizeUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                               kFloat_GrSLType, kDefault_GrSLPrecision,
                                               "InvSize");
    const char* colorCubeInvSizeUni = builder->getUniformCStr(fColorCubeInvSizeUni);

    const char* nonZeroAlpha = "nonZeroAlpha";
    const char* unPMColor = "unPMColor";
    const char* cubeIdx = "cubeIdx";
    const char* cCoords1 = "cCoords1";
    const char* cCoords2 = "cCoords2";

    // Note: if implemented using texture3D in OpenGL ES older than OpenGL ES 3.0,
    //       the shader might need "#extension GL_OES_texture_3D : enable".

    GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();

    // Unpremultiply color
    fsBuilder->codeAppendf("\tfloat %s = max(%s.a, 0.00001);\n", nonZeroAlpha, inputColor);
    fsBuilder->codeAppendf("\tvec4 %s = vec4(%s.rgb / %s, %s);\n",
                           unPMColor, inputColor, nonZeroAlpha, nonZeroAlpha);

    // Fit input color into the cube.
    fsBuilder->codeAppendf(
        "vec3 %s = vec3(%s.rg * vec2((%s - 1.0) * %s) + vec2(0.5 * %s), %s.b * (%s - 1.0));\n",
        cubeIdx, unPMColor, colorCubeSizeUni, colorCubeInvSizeUni, colorCubeInvSizeUni,
        unPMColor, colorCubeSizeUni);

    // Compute y coord for for texture fetches.
    fsBuilder->codeAppendf("vec2 %s = vec2(%s.r, (floor(%s.b) + %s.g) * %s);\n",
                           cCoords1, cubeIdx, cubeIdx, cubeIdx, colorCubeInvSizeUni);
    fsBuilder->codeAppendf("vec2 %s = vec2(%s.r, (ceil(%s.b) + %s.g) * %s);\n",
                           cCoords2, cubeIdx, cubeIdx, cubeIdx, colorCubeInvSizeUni);

    // Apply the cube.
    fsBuilder->codeAppendf("%s = vec4(mix(", outputColor);
    fsBuilder->appendTextureLookup(samplers[0], cCoords1);
    fsBuilder->codeAppend(".rgb, ");
    fsBuilder->appendTextureLookup(samplers[0], cCoords2);

    // Premultiply color by alpha. Note that the input alpha is not modified by this shader.
    fsBuilder->codeAppendf(".rgb, fract(%s.b)) * vec3(%s), %s.a);\n",
                           cubeIdx, nonZeroAlpha, inputColor);
}

void GrGLConvolutionEffect::emitCode(GrGLFPBuilder* builder,
                                     const GrFragmentProcessor&,
                                     const char* outputColor,
                                     const char* inputColor,
                                     const TransformedCoordsArray& coords,
                                     const TextureSamplerArray& samplers) {
    fImageIncrementUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                             kVec2f_GrSLType, kDefault_GrSLPrecision,
                                             "ImageIncrement");
    if (this->useBounds()) {
        fBoundsUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                         kVec2f_GrSLType, kDefault_GrSLPrecision,
                                         "Bounds");
    }
    fKernelUni = builder->addUniformArray(GrGLProgramBuilder::kFragment_Visibility,
                                          kFloat_GrSLType, kDefault_GrSLPrecision,
                                          "Kernel", this->width());

    GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
    SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 0);

    fsBuilder->codeAppendf("\t\t%s = vec4(0, 0, 0, 0);\n", outputColor);

    int width = this->width();
    const GrGLShaderVar& kernel = builder->getUniformVariable(fKernelUni);
    const char* imgInc = builder->getUniformCStr(fImageIncrementUni);

    fsBuilder->codeAppendf("\t\tvec2 coord = %s - %d.0 * %s;\n", coords2D.c_str(), fRadius, imgInc);

    // Manually unroll loop because some drivers don't; yields 20-30% speedup.
    for (int i = 0; i < width; i++) {
        SkString index;
        SkString kernelIndex;
        index.appendS32(i);
        kernel.appendArrayAccess(index.c_str(), &kernelIndex);
        fsBuilder->codeAppendf("\t\t%s += ", outputColor);
        fsBuilder->appendTextureLookup(samplers[0], "coord");
        if (this->useBounds()) {
            const char* bounds = builder->getUniformCStr(fBoundsUni);
            const char* component = this->direction() == Gr1DKernelEffect::kY_Direction ? "y" : "x";
            fsBuilder->codeAppendf(" * float(coord.%s >= %s.x && coord.%s <= %s.y)",
                component, bounds, component, bounds);
        }
        fsBuilder->codeAppendf(" * %s;\n", kernelIndex.c_str());
        fsBuilder->codeAppendf("\t\tcoord += %s;\n", imgInc);
    }

    SkString modulate;
    GrGLSLMulVarBy4f(&modulate, outputColor, inputColor);
    fsBuilder->codeAppend(modulate.c_str());
}

void GLAARectEffect::emitCode(EmitArgs& args) {
    const AARectEffect& aare = args.fFp.cast<AARectEffect>();
    const char *rectName;
    // The rect uniform's xyzw refer to (left + 0.5, top + 0.5, right - 0.5, bottom - 0.5),
    // respectively.
    fRectUniform = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                       kVec4f_GrSLType,
                                       kDefault_GrSLPrecision,
                                       "rect",
                                       &rectName);

    GrGLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
    const char* fragmentPos = fsBuilder->fragmentPosition();
    if (GrProcessorEdgeTypeIsAA(aare.getEdgeType())) {
        // The amount of coverage removed in x and y by the edges is computed as a pair of negative
        // numbers, xSub and ySub.
        fsBuilder->codeAppend("\t\tfloat xSub, ySub;\n");
        fsBuilder->codeAppendf("\t\txSub = min(%s.x - %s.x, 0.0);\n", fragmentPos, rectName);
        fsBuilder->codeAppendf("\t\txSub += min(%s.z - %s.x, 0.0);\n", rectName, fragmentPos);
        fsBuilder->codeAppendf("\t\tySub = min(%s.y - %s.y, 0.0);\n", fragmentPos, rectName);
        fsBuilder->codeAppendf("\t\tySub += min(%s.w - %s.y, 0.0);\n", rectName, fragmentPos);
        // Now compute coverage in x and y and multiply them to get the fraction of the pixel
        // covered.
        fsBuilder->codeAppendf("\t\tfloat alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));\n");
    } else {
        fsBuilder->codeAppendf("\t\tfloat alpha = 1.0;\n");
        fsBuilder->codeAppendf("\t\talpha *= (%s.x - %s.x) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
        fsBuilder->codeAppendf("\t\talpha *= (%s.z - %s.x) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
        fsBuilder->codeAppendf("\t\talpha *= (%s.y - %s.y) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
        fsBuilder->codeAppendf("\t\talpha *= (%s.w - %s.y) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
    }

    if (GrProcessorEdgeTypeIsInverseFill(aare.getEdgeType())) {
        fsBuilder->codeAppend("\t\talpha = 1.0 - alpha;\n");
    }
    fsBuilder->codeAppendf("\t\t%s = %s;\n", args.fOutputColor,
                           (GrGLSLExpr4(args.fInputColor) * GrGLSLExpr1("alpha")).c_str());
}

 virtual void emitCode(GrGLFPBuilder* builder,
                       const GrFragmentProcessor& fp,
                       const char* outputColor,
                       const char* inputColor,
                       const TransformedCoordsArray& coords,
                       const TextureSamplerArray& samplers) override {
     GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
     fsBuilder->codeAppendf("\t%s = ", outputColor);
     fsBuilder->appendTextureLookupAndModulate(inputColor,
                                               samplers[0],
                                               coords[0].c_str(),
                                               coords[0].getType());
     fsBuilder->codeAppend(";\n");
 }

    void emitCode(EmitArgs& args) override {
        GrGLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
        fsBuilder->codeAppend("vec4 bgColor = ");
        fsBuilder->appendTextureLookup(args.fSamplers[0], args.fCoords[0].c_str(),
                                       args.fCoords[0].getType());
        fsBuilder->codeAppendf(";");
        const char* dstColor = "bgColor";

        fKUni = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                    kVec4f_GrSLType, kDefault_GrSLPrecision,
                                    "k");
        const char* kUni = args.fBuilder->getUniformCStr(fKUni);

        add_arithmetic_code(fsBuilder, args.fInputColor, dstColor, args.fOutputColor, kUni,
                            fEnforcePMColor);
    }

        void emitCode(GrGLFPBuilder* builder,
                      const GrFragmentProcessor& fp,
                      const char* outputColor,
                      const char* inputColor,
                      const TransformedCoordsArray& coords,
                      const TextureSamplerArray& samplers) override {

            GrGLFragmentBuilder* fpb = builder->getFragmentShaderBuilder();

            // add uniforms
            const char* lightDirUniName = NULL;
            fLightDirUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                               kVec3f_GrSLType, kDefault_GrSLPrecision,
                                               "LightDir", &lightDirUniName);

            const char* lightColorUniName = NULL;
            fLightColorUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                                 kVec4f_GrSLType, kDefault_GrSLPrecision,
                                                 "LightColor", &lightColorUniName);

            const char* ambientColorUniName = NULL;
            fAmbientColorUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                                   kVec4f_GrSLType, kDefault_GrSLPrecision,
                                                   "AmbientColor", &ambientColorUniName);

            fpb->codeAppend("vec4 diffuseColor = ");
            fpb->appendTextureLookupAndModulate(inputColor, samplers[0], 
                                                coords[0].c_str(), coords[0].getType());
            fpb->codeAppend(";");

            fpb->codeAppend("vec4 normalColor = ");
            fpb->appendTextureLookup(samplers[1], coords[0].c_str(), coords[0].getType());
            fpb->codeAppend(";");

            fpb->codeAppend("vec3 normal = normalize(2.0*(normalColor.rgb - vec3(0.5)));");
            fpb->codeAppendf("vec3 lightDir = normalize(%s);", lightDirUniName);
            fpb->codeAppend("float NdotL = dot(normal, lightDir);");
            // diffuse light
            fpb->codeAppendf("vec3 result = %s.rgb*diffuseColor.rgb*NdotL;", lightColorUniName);
            // ambient light
            fpb->codeAppendf("result += %s.rgb;", ambientColorUniName);
            fpb->codeAppendf("%s = vec4(result.rgb, diffuseColor.a);", outputColor);
        }

void GrGLDisplacementMapEffect::emitCode(GrGLFPBuilder* builder,
                                         const GrFragmentProcessor& fp,
                                         const char* outputColor,
                                         const char* inputColor,
                                         const TransformedCoordsArray& coords,
                                         const TextureSamplerArray& samplers) {
    const GrTextureDomain& domain = fp.cast<GrDisplacementMapEffect>().domain();
    sk_ignore_unused_variable(inputColor);

    fScaleUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                    kVec2f_GrSLType, kDefault_GrSLPrecision, "Scale");
    const char* scaleUni = builder->getUniformCStr(fScaleUni);
    const char* dColor = "dColor";
    const char* cCoords = "cCoords";
    const char* nearZero = "1e-6"; // Since 6.10352e−5 is the smallest half float, use
                                   // a number smaller than that to approximate 0, but
                                   // leave room for 32-bit float GPU rounding errors.

    GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
    fsBuilder->codeAppendf("\t\tvec4 %s = ", dColor);
    fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType());
    fsBuilder->codeAppend(";\n");

    // Unpremultiply the displacement
    fsBuilder->codeAppendf("\t\t%s.rgb = (%s.a < %s) ? vec3(0.0) : clamp(%s.rgb / %s.a, 0.0, 1.0);",
                           dColor, dColor, nearZero, dColor, dColor);
    SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 1);
    fsBuilder->codeAppendf("\t\tvec2 %s = %s + %s*(%s.",
                           cCoords, coords2D.c_str(), scaleUni, dColor);

    switch (fXChannelSelector) {
      case SkDisplacementMapEffect::kR_ChannelSelectorType:
        fsBuilder->codeAppend("r");
        break;
      case SkDisplacementMapEffect::kG_ChannelSelectorType:
        fsBuilder->codeAppend("g");
        break;
      case SkDisplacementMapEffect::kB_ChannelSelectorType:
        fsBuilder->codeAppend("b");
        break;
      case SkDisplacementMapEffect::kA_ChannelSelectorType:
        fsBuilder->codeAppend("a");
        break;
      case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
      default:
        SkDEBUGFAIL("Unknown X channel selector");
    }

    switch (fYChannelSelector) {
      case SkDisplacementMapEffect::kR_ChannelSelectorType:
        fsBuilder->codeAppend("r");
        break;
      case SkDisplacementMapEffect::kG_ChannelSelectorType:
        fsBuilder->codeAppend("g");
        break;
      case SkDisplacementMapEffect::kB_ChannelSelectorType:
        fsBuilder->codeAppend("b");
        break;
      case SkDisplacementMapEffect::kA_ChannelSelectorType:
        fsBuilder->codeAppend("a");
        break;
      case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
      default:
        SkDEBUGFAIL("Unknown Y channel selector");
    }
    fsBuilder->codeAppend("-vec2(0.5));\t\t");

    fGLDomain.sampleTexture(fsBuilder, domain, outputColor, SkString(cCoords), samplers[1]);
    fsBuilder->codeAppend(";\n");
}

void GrGLConicEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
    GrGLGPBuilder* pb = args.fPB;
    GrGLVertexBuilder* vsBuilder = args.fPB->getVertexShaderBuilder();
    const GrConicEffect& gp = args.fGP.cast<GrConicEffect>();
    const ConicBatchTracker& local = args.fBT.cast<ConicBatchTracker>();

    // emit attributes
    vsBuilder->emitAttributes(gp);

    GrGLVertToFrag v(kVec4f_GrSLType);
    args.fPB->addVarying("ConicCoeffs", &v);
    vsBuilder->codeAppendf("%s = %s;", v.vsOut(), gp.inConicCoeffs()->fName);

    // Setup pass through color
    this->setupColorPassThrough(args.fPB, local.fInputColorType, args.fOutputColor, NULL,
                                &fColorUniform);

    // Setup position
    this->setupPosition(pb, gpArgs, gp.inPosition()->fName, gp.viewMatrix());

    // emit transforms with position
    this->emitTransforms(pb, gpArgs->fPositionVar, gp.inPosition()->fName, gp.localMatrix(),
                         args.fTransformsIn, args.fTransformsOut);

    GrGLFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
    fsBuilder->codeAppend("float edgeAlpha;");

    switch (fEdgeType) {
        case kHairlineAA_GrProcessorEdgeType: {
            SkAssertResult(fsBuilder->enableFeature(
                    GrGLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
            fsBuilder->codeAppendf("vec3 dklmdx = dFdx(%s.xyz);", v.fsIn());
            fsBuilder->codeAppendf("vec3 dklmdy = dFdy(%s.xyz);", v.fsIn());
            fsBuilder->codeAppendf("float dfdx ="
                                   "2.0 * %s.x * dklmdx.x - %s.y * dklmdx.z - %s.z * dklmdx.y;",
                                   v.fsIn(), v.fsIn(), v.fsIn());
            fsBuilder->codeAppendf("float dfdy ="
                                   "2.0 * %s.x * dklmdy.x - %s.y * dklmdy.z - %s.z * dklmdy.y;",
                                   v.fsIn(), v.fsIn(), v.fsIn());
            fsBuilder->codeAppend("vec2 gF = vec2(dfdx, dfdy);");
            fsBuilder->codeAppend("float gFM = sqrt(dot(gF, gF));");
            fsBuilder->codeAppendf("float func = %s.x*%s.x - %s.y*%s.z;", v.fsIn(), v.fsIn(),
                                   v.fsIn(), v.fsIn());
            fsBuilder->codeAppend("func = abs(func);");
            fsBuilder->codeAppend("edgeAlpha = func / gFM;");
            fsBuilder->codeAppend("edgeAlpha = max(1.0 - edgeAlpha, 0.0);");
            // Add line below for smooth cubic ramp
            // fsBuilder->codeAppend("edgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);");
            break;
        }
        case kFillAA_GrProcessorEdgeType: {
            SkAssertResult(fsBuilder->enableFeature(
                    GrGLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
            fsBuilder->codeAppendf("vec3 dklmdx = dFdx(%s.xyz);", v.fsIn());
            fsBuilder->codeAppendf("vec3 dklmdy = dFdy(%s.xyz);", v.fsIn());
            fsBuilder->codeAppendf("float dfdx ="
                                   "2.0 * %s.x * dklmdx.x - %s.y * dklmdx.z - %s.z * dklmdx.y;",
                                   v.fsIn(), v.fsIn(), v.fsIn());
            fsBuilder->codeAppendf("float dfdy ="
                                   "2.0 * %s.x * dklmdy.x - %s.y * dklmdy.z - %s.z * dklmdy.y;",
                                   v.fsIn(), v.fsIn(), v.fsIn());
            fsBuilder->codeAppend("vec2 gF = vec2(dfdx, dfdy);");
            fsBuilder->codeAppend("float gFM = sqrt(dot(gF, gF));");
            fsBuilder->codeAppendf("float func = %s.x * %s.x - %s.y * %s.z;", v.fsIn(), v.fsIn(),
                                   v.fsIn(), v.fsIn());
            fsBuilder->codeAppend("edgeAlpha = func / gFM;");
            fsBuilder->codeAppend("edgeAlpha = clamp(1.0 - edgeAlpha, 0.0, 1.0);");
            // Add line below for smooth cubic ramp
            // fsBuilder->codeAppend("edgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);");
            break;
        }
        case kFillBW_GrProcessorEdgeType: {
            fsBuilder->codeAppendf("edgeAlpha = %s.x * %s.x - %s.y * %s.z;", v.fsIn(), v.fsIn(),
                                   v.fsIn(), v.fsIn());
            fsBuilder->codeAppend("edgeAlpha = float(edgeAlpha < 0.0);");
            break;
        }
        default:
            SkFAIL("Shouldn't get here");
    }

    if (0xff != local.fCoverageScale) {
        const char* coverageScale;
        fCoverageScaleUniform = pb->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                               kFloat_GrSLType,
                                               kDefault_GrSLPrecision,
                                               "Coverage",
                                               &coverageScale);
        fsBuilder->codeAppendf("%s = vec4(%s * edgeAlpha);", args.fOutputCoverage, coverageScale);
    } else {
        fsBuilder->codeAppendf("%s = vec4(edgeAlpha);", args.fOutputCoverage);
    }
}