C++ GrGLFragmentBuilder::ensureFSCoords2D方法代码示例

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 GrGLMagnifierEffect::emitCode(GrGLFPBuilder* builder,
                                   const GrFragmentProcessor&,
                                   const char* outputColor,
                                   const char* inputColor,
                                   const TransformedCoordsArray& coords,
                                   const TextureSamplerArray& samplers) {
    fOffsetVar = builder->addUniform(
        GrGLProgramBuilder::kFragment_Visibility |
        GrGLProgramBuilder::kVertex_Visibility,
        kVec2f_GrSLType, kDefault_GrSLPrecision, "Offset");
    fInvZoomVar = builder->addUniform(
        GrGLProgramBuilder::kFragment_Visibility |
        GrGLProgramBuilder::kVertex_Visibility,
        kVec2f_GrSLType, kDefault_GrSLPrecision, "InvZoom");
    fInvInsetVar = builder->addUniform(
        GrGLProgramBuilder::kFragment_Visibility |
        GrGLProgramBuilder::kVertex_Visibility,
        kVec2f_GrSLType, kDefault_GrSLPrecision, "InvInset");
    fBoundsVar = builder->addUniform(
        GrGLProgramBuilder::kFragment_Visibility |
        GrGLProgramBuilder::kVertex_Visibility,
        kVec4f_GrSLType, kDefault_GrSLPrecision, "Bounds");

    GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
    SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 0);
    fsBuilder->codeAppendf("\t\tvec2 coord = %s;\n", coords2D.c_str());
    fsBuilder->codeAppendf("\t\tvec2 zoom_coord = %s + %s * %s;\n",
                           builder->getUniformCStr(fOffsetVar),
                           coords2D.c_str(),
                           builder->getUniformCStr(fInvZoomVar));
    const char* bounds = builder->getUniformCStr(fBoundsVar);
    fsBuilder->codeAppendf("\t\tvec2 delta = (coord - %s.xy) * %s.zw;\n", bounds, bounds);
    fsBuilder->codeAppendf("\t\tdelta = min(delta, vec2(1.0, 1.0) - delta);\n");
    fsBuilder->codeAppendf("\t\tdelta = delta * %s;\n", builder->getUniformCStr(fInvInsetVar));

    fsBuilder->codeAppend("\t\tfloat weight = 0.0;\n");
    fsBuilder->codeAppend("\t\tif (delta.s < 2.0 && delta.t < 2.0) {\n");
    fsBuilder->codeAppend("\t\t\tdelta = vec2(2.0, 2.0) - delta;\n");
    fsBuilder->codeAppend("\t\t\tfloat dist = length(delta);\n");
    fsBuilder->codeAppend("\t\t\tdist = max(2.0 - dist, 0.0);\n");
    fsBuilder->codeAppend("\t\t\tweight = min(dist * dist, 1.0);\n");
    fsBuilder->codeAppend("\t\t} else {\n");
    fsBuilder->codeAppend("\t\t\tvec2 delta_squared = delta * delta;\n");
    fsBuilder->codeAppend("\t\t\tweight = min(min(delta_squared.x, delta_squared.y), 1.0);\n");
    fsBuilder->codeAppend("\t\t}\n");

    fsBuilder->codeAppend("\t\tvec2 mix_coord = mix(coord, zoom_coord, weight);\n");
    fsBuilder->codeAppend("\t\tvec4 output_color = ");
    fsBuilder->appendTextureLookup(samplers[0], "mix_coord");
    fsBuilder->codeAppend(";\n");

    fsBuilder->codeAppendf("\t\t%s = output_color;", outputColor);
    SkString modulate;
    GrGLSLMulVarBy4f(&modulate, outputColor, inputColor);
    fsBuilder->codeAppend(modulate.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 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 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());
 }

void GrGLPerlinNoise::emitCode(GrGLFPBuilder* builder,
                               const GrFragmentProcessor&,
                               const char* outputColor,
                               const char* inputColor,
                               const TransformedCoordsArray& coords,
                               const TextureSamplerArray& samplers) {
    sk_ignore_unused_variable(inputColor);

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

    fBaseFrequencyUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                            kVec2f_GrSLType, kDefault_GrSLPrecision,
                                            "baseFrequency");
    const char* baseFrequencyUni = builder->getUniformCStr(fBaseFrequencyUni);
    fAlphaUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                    kFloat_GrSLType, kDefault_GrSLPrecision,
                                    "alpha");
    const char* alphaUni = builder->getUniformCStr(fAlphaUni);

    const char* stitchDataUni = NULL;
    if (fStitchTiles) {
        fStitchDataUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                             kVec2f_GrSLType, kDefault_GrSLPrecision,
                                             "stitchData");
        stitchDataUni = builder->getUniformCStr(fStitchDataUni);
    }

    // There are 4 lines, so the center of each line is 1/8, 3/8, 5/8 and 7/8
    const char* chanCoordR  = "0.125";
    const char* chanCoordG  = "0.375";
    const char* chanCoordB  = "0.625";
    const char* chanCoordA  = "0.875";
    const char* chanCoord   = "chanCoord";
    const char* stitchData  = "stitchData";
    const char* ratio       = "ratio";
    const char* noiseVec    = "noiseVec";
    const char* noiseSmooth = "noiseSmooth";
    const char* floorVal    = "floorVal";
    const char* fractVal    = "fractVal";
    const char* uv          = "uv";
    const char* ab          = "ab";
    const char* latticeIdx  = "latticeIdx";
    const char* bcoords     = "bcoords";
    const char* lattice     = "lattice";
    const char* inc8bit     = "0.00390625";  // 1.0 / 256.0
    // This is the math to convert the two 16bit integer packed into rgba 8 bit input into a
    // [-1,1] vector and perform a dot product between that vector and the provided vector.
    const char* dotLattice  = "dot(((%s.ga + %s.rb * vec2(%s)) * vec2(2.0) - vec2(1.0)), %s);";

    // Add noise function
    static const GrGLShaderVar gPerlinNoiseArgs[] =  {
        GrGLShaderVar(chanCoord, kFloat_GrSLType),
        GrGLShaderVar(noiseVec, kVec2f_GrSLType)
    };

    static const GrGLShaderVar gPerlinNoiseStitchArgs[] =  {
        GrGLShaderVar(chanCoord, kFloat_GrSLType),
        GrGLShaderVar(noiseVec, kVec2f_GrSLType),
        GrGLShaderVar(stitchData, kVec2f_GrSLType)
    };

    SkString noiseCode;

    noiseCode.appendf("\tvec4 %s;\n", floorVal);
    noiseCode.appendf("\t%s.xy = floor(%s);\n", floorVal, noiseVec);
    noiseCode.appendf("\t%s.zw = %s.xy + vec2(1.0);\n", floorVal, floorVal);
    noiseCode.appendf("\tvec2 %s = fract(%s);\n", fractVal, noiseVec);

    // smooth curve : t * t * (3 - 2 * t)
    noiseCode.appendf("\n\tvec2 %s = %s * %s * (vec2(3.0) - vec2(2.0) * %s);",
        noiseSmooth, fractVal, fractVal, fractVal);

    // Adjust frequencies if we're stitching tiles
    if (fStitchTiles) {
        noiseCode.appendf("\n\tif(%s.x >= %s.x) { %s.x -= %s.x; }",
            floorVal, stitchData, floorVal, stitchData);
        noiseCode.appendf("\n\tif(%s.y >= %s.y) { %s.y -= %s.y; }",
            floorVal, stitchData, floorVal, stitchData);
        noiseCode.appendf("\n\tif(%s.z >= %s.x) { %s.z -= %s.x; }",
            floorVal, stitchData, floorVal, stitchData);
        noiseCode.appendf("\n\tif(%s.w >= %s.y) { %s.w -= %s.y; }",
            floorVal, stitchData, floorVal, stitchData);
    }

    // Get texture coordinates and normalize
    noiseCode.appendf("\n\t%s = fract(floor(mod(%s, 256.0)) / vec4(256.0));\n",
        floorVal, floorVal);

    // Get permutation for x
    {
        SkString xCoords("");
        xCoords.appendf("vec2(%s.x, 0.5)", floorVal);

        noiseCode.appendf("\n\tvec2 %s;\n\t%s.x = ", latticeIdx, latticeIdx);
        fsBuilder->appendTextureLookup(&noiseCode, samplers[0], xCoords.c_str(), kVec2f_GrSLType);
        noiseCode.append(".r;");
    }

    // Get permutation for x + 1
//.........这里部分代码省略.........

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 GrGLMorphologyEffect::emitCode(EmitArgs& args) {
    fPixelSizeUni = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                            kFloat_GrSLType, kDefault_GrSLPrecision,
                                            "PixelSize");
    const char* pixelSizeInc = args.fBuilder->getUniformCStr(fPixelSizeUni);
    fRangeUni = args.fBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                            kVec2f_GrSLType, kDefault_GrSLPrecision,
                                            "Range");
    const char* range = args.fBuilder->getUniformCStr(fRangeUni);

    GrGLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
    SkString coords2D = fsBuilder->ensureFSCoords2D(args.fCoords, 0);
    const char* func;
    switch (fType) {
        case GrMorphologyEffect::kErode_MorphologyType:
            fsBuilder->codeAppendf("\t\t%s = vec4(1, 1, 1, 1);\n", args.fOutputColor);
            func = "min";
            break;
        case GrMorphologyEffect::kDilate_MorphologyType:
            fsBuilder->codeAppendf("\t\t%s = vec4(0, 0, 0, 0);\n", args.fOutputColor);
            func = "max";
            break;
        default:
            SkFAIL("Unexpected type");
            func = ""; // suppress warning
            break;
    }

    const char* dir;
    switch (fDirection) {
        case Gr1DKernelEffect::kX_Direction:
            dir = "x";
            break;
        case Gr1DKernelEffect::kY_Direction:
            dir = "y";
            break;
        default:
            SkFAIL("Unknown filter direction.");
            dir = ""; // suppress warning
    }

    // vec2 coord = coord2D;
    fsBuilder->codeAppendf("\t\tvec2 coord = %s;\n", coords2D.c_str());
    // coord.x -= radius * pixelSize;
    fsBuilder->codeAppendf("\t\tcoord.%s -= %d.0 * %s; \n", dir, fRadius, pixelSizeInc);
    if (fUseRange) {
        // highBound = min(highBound, coord.x + (width-1) * pixelSize);
        fsBuilder->codeAppendf("\t\tfloat highBound = min(%s.y, coord.%s + %f * %s);",
                               range, dir, float(width() - 1), pixelSizeInc);
        // coord.x = max(lowBound, coord.x);
        fsBuilder->codeAppendf("\t\tcoord.%s = max(%s.x, coord.%s);", dir, range, dir);
    }
    fsBuilder->codeAppendf("\t\tfor (int i = 0; i < %d; i++) {\n", width());
    fsBuilder->codeAppendf("\t\t\t%s = %s(%s, ", args.fOutputColor, func, args.fOutputColor);
    fsBuilder->appendTextureLookup(args.fSamplers[0], "coord");
    fsBuilder->codeAppend(");\n");
    // coord.x += pixelSize;
    fsBuilder->codeAppendf("\t\t\tcoord.%s += %s;\n", dir, pixelSizeInc);
    if (fUseRange) {
        // coord.x = min(highBound, coord.x);
        fsBuilder->codeAppendf("\t\t\tcoord.%s = min(highBound, coord.%s);", dir, dir);
    }
    fsBuilder->codeAppend("\t\t}\n");
    SkString modulate;
    GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
    fsBuilder->codeAppend(modulate.c_str());
}