C++ GrGLSLFragmentBuilder类代码示例

 void emitCode(EmitArgs& args) override {
     GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
     const char* colorUni;
     fColorUniform = args.fUniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
                                                      kVec4f_GrSLType, kMedium_GrSLPrecision,
                                                      "constantColor",
                                                      &colorUni);
     GrConstColorProcessor::InputMode mode = args.fFp.cast<GrConstColorProcessor>().inputMode();
     if (!args.fInputColor) {
         mode = GrConstColorProcessor::kIgnore_InputMode;
     }
     switch (mode) {
         case GrConstColorProcessor::kIgnore_InputMode:
             fragBuilder->codeAppendf("%s = %s;", args.fOutputColor, colorUni);
             break;
         case GrConstColorProcessor::kModulateRGBA_InputMode:
             fragBuilder->codeAppendf("%s = %s * %s;", args.fOutputColor, args.fInputColor,
                                    colorUni);
             break;
         case GrConstColorProcessor::kModulateA_InputMode:
             fragBuilder->codeAppendf("%s = %s.a * %s;", args.fOutputColor, args.fInputColor,
                                    colorUni);
             break;
     }
 }

void GrGLConvexPolyEffect::emitCode(EmitArgs& args) {
    const GrConvexPolyEffect& cpe = args.fFp.cast<GrConvexPolyEffect>();

    const char *edgeArrayName;
    fEdgeUniform = args.fUniformHandler->addUniformArray(GrGLSLUniformHandler::kFragment_Visibility,
                                                         kVec3f_GrSLType,
                                                         kDefault_GrSLPrecision,
                                                         "edges",
                                                         cpe.getEdgeCount(),
                                                         &edgeArrayName);
    GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
    fragBuilder->codeAppend("\t\tfloat alpha = 1.0;\n");
    fragBuilder->codeAppend("\t\tfloat edge;\n");
    const char* fragmentPos = fragBuilder->fragmentPosition();
    for (int i = 0; i < cpe.getEdgeCount(); ++i) {
        fragBuilder->codeAppendf("\t\tedge = dot(%s[%d], vec3(%s.x, %s.y, 1));\n",
                                 edgeArrayName, i, fragmentPos, fragmentPos);
        if (GrProcessorEdgeTypeIsAA(cpe.getEdgeType())) {
            fragBuilder->codeAppend("\t\tedge = clamp(edge, 0.0, 1.0);\n");
        } else {
            fragBuilder->codeAppend("\t\tedge = edge >= 0.5 ? 1.0 : 0.0;\n");
        }
        fragBuilder->codeAppend("\t\talpha *= edge;\n");
    }

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

        void emitCode(EmitArgs& args) override {
            GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
            fMatrixHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
                                                       kMat44f_GrSLType, kDefault_GrSLPrecision,
                                                       "ColorMatrix");
            fVectorHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
                                                       kVec4f_GrSLType, kDefault_GrSLPrecision,
                                                       "ColorMatrixVector");

            if (nullptr == args.fInputColor) {
                // could optimize this case, but we aren't for now.
                args.fInputColor = "vec4(1)";
            }
            GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
            // The max() is to guard against 0 / 0 during unpremul when the incoming color is
            // transparent black.
            fragBuilder->codeAppendf("\tfloat nonZeroAlpha = max(%s.a, 0.00001);\n",
                                     args.fInputColor);
            fragBuilder->codeAppendf("\t%s = %s * vec4(%s.rgb / nonZeroAlpha, nonZeroAlpha) + %s;\n",
                                     args.fOutputColor,
                                     uniformHandler->getUniformCStr(fMatrixHandle),
                                     args.fInputColor,
                                     uniformHandler->getUniformCStr(fVectorHandle));
            fragBuilder->codeAppendf("\t%s = clamp(%s, 0.0, 1.0);\n",
                                     args.fOutputColor, args.fOutputColor);
            fragBuilder->codeAppendf("\t%s.rgb *= %s.a;\n", args.fOutputColor, args.fOutputColor);
        }

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

 virtual void emitCode(EmitArgs& args) override {
     // pass through
     GrGLSLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
     if (args.fInputColor) {
         fsBuilder->codeAppendf("%s = %s;\n", args.fOutputColor, args.fInputColor);
     } else {
         fsBuilder->codeAppendf("%s = vec4(1.0);\n", args.fOutputColor);
     }
 }

void GrGLSLFragmentProcessor::emitChild(int childIndex, const char* inputColor,
                                        SkString* outputColor, EmitArgs& args) {

    SkASSERT(outputColor);
    GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
    outputColor->append(fragBuilder->getMangleString());
    fragBuilder->codeAppendf("vec4 %s;", outputColor->c_str());
    this->internalEmitChild(childIndex, inputColor, outputColor->c_str(), args);
}

 void emitCode(EmitArgs& args) override {
     // pass through
     GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
     if (args.fInputColor) {
         fragBuilder->codeAppendf("%s = %s;\n", args.fOutputColor, args.fInputColor);
     } else {
         fragBuilder->codeAppendf("%s = vec4(1.0);\n", args.fOutputColor);
     }
 }

        void emitCode(EmitArgs& args) override {
            if (nullptr == args.fInputColor) {
                args.fInputColor = "vec4(1)";
            }

            GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
            fragBuilder->codeAppendf("\tfloat luma = dot(vec3(%f, %f, %f), %s.rgb);\n",
                                     SK_ITU_BT709_LUM_COEFF_R,
                                     SK_ITU_BT709_LUM_COEFF_G,
                                     SK_ITU_BT709_LUM_COEFF_B,
                                     args.fInputColor);
            fragBuilder->codeAppendf("\t%s = vec4(0, 0, 0, luma);\n",
                                     args.fOutputColor);

        }

void GLDitherEffect::emitCode(EmitArgs& args) {
    GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
    // Generate a random number based on the fragment position. For this
    // random number generator, we use the "GLSL rand" function
    // that seems to be floating around on the internet. It works under
    // the assumption that sin(<big number>) oscillates with high frequency
    // and sampling it will generate "randomness". Since we're using this
    // for rendering and not cryptography it should be OK.

    // For each channel c, add the random offset to the pixel to either bump
    // it up or let it remain constant during quantization.
    fragBuilder->codeAppendf("\t\tfloat r = "
                             "fract(sin(dot(%s.xy ,vec2(12.9898,78.233))) * 43758.5453);\n",
                             fragBuilder->fragmentPosition());
    fragBuilder->codeAppendf("\t\t%s = (1.0/255.0) * vec4(r, r, r, r) + %s;\n",
                             args.fOutputColor, GrGLSLExpr4(args.fInputColor).c_str());
}

    void emitCode(EmitArgs& args) override {
        GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
        const GrPathProcessor& pathProc = args.fGP.cast<GrPathProcessor>();

        // emit transforms
        this->emitTransforms(args.fVaryingHandler, args.fTransformsIn, args.fTransformsOut);

        // Setup uniform color
        if (pathProc.overrides().readsColor()) {
            const char* stagedLocalVarName;
            fColorUniform = args.fUniformHandler->addUniform(
                                                         GrGLSLUniformHandler::kFragment_Visibility,
                                                         kVec4f_GrSLType,
                                                         kDefault_GrSLPrecision,
                                                         "Color",
                                                         &stagedLocalVarName);
            fragBuilder->codeAppendf("%s = %s;", args.fOutputColor, stagedLocalVarName);
        }

        // setup constant solid coverage
        if (pathProc.overrides().readsCoverage()) {
            fragBuilder->codeAppendf("%s = vec4(1);", args.fOutputCoverage);
        }
    }

 void emitCode(EmitArgs& args) override {
     GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
     fragBuilder->codeAppendf("vec2 c = %s;",
                              fragBuilder->ensureFSCoords2D(args.fCoords, 0).c_str());
     fragBuilder->codeAppend("vec2 r = mod(c, vec2(20.0));");
     fragBuilder->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);");
     fragBuilder->codeAppendf("color.rgb *= color.a;"
                              "%s = color * %s;",
                              args.fOutputColor, GrGLSLExpr4(args.fInputColor).c_str());
 }

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

    fScaleUni = args.fBuilder->addUniform(GrGLSLProgramBuilder::kFragment_Visibility,
                                          kVec2f_GrSLType, kDefault_GrSLPrecision, "Scale");
    const char* scaleUni = args.fBuilder->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.

    GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
    fragBuilder->codeAppendf("\t\tvec4 %s = ", dColor);
    fragBuilder->appendTextureLookup(args.fSamplers[0], args.fCoords[0].c_str(),
                                   args.fCoords[0].getType());
    fragBuilder->codeAppend(";\n");

    // Unpremultiply the displacement
    fragBuilder->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 = fragBuilder->ensureFSCoords2D(args.fCoords, 1);
    fragBuilder->codeAppendf("\t\tvec2 %s = %s + %s*(%s.",
                             cCoords, coords2D.c_str(), scaleUni, dColor);

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

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

    fGLDomain.sampleTexture(fragBuilder,
                            args.fGLSLCaps,
                            domain,
                            args.fOutputColor,
                            SkString(cCoords),
                            args.fSamplers[1]);
    fragBuilder->codeAppend(";\n");
}

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

    GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
    SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
    const char* func;
    switch (fType) {
    case GrMorphologyEffect::kErode_MorphologyType:
        fragBuilder->codeAppendf("\t\t%s = vec4(1, 1, 1, 1);\n", args.fOutputColor);
        func = "min";
        break;
    case GrMorphologyEffect::kDilate_MorphologyType:
        fragBuilder->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;
    fragBuilder->codeAppendf("\t\tvec2 coord = %s;\n", coords2D.c_str());
    // coord.x -= radius * pixelSize;
    fragBuilder->codeAppendf("\t\tcoord.%s -= %d.0 * %s; \n", dir, fRadius, pixelSizeInc);
    if (fUseRange) {
        // highBound = min(highBound, coord.x + (width-1) * pixelSize);
        fragBuilder->codeAppendf("\t\tfloat highBound = min(%s.y, coord.%s + %f * %s);",
                                 range, dir, float(width() - 1), pixelSizeInc);
        // coord.x = max(lowBound, coord.x);
        fragBuilder->codeAppendf("\t\tcoord.%s = max(%s.x, coord.%s);", dir, range, dir);
    }
    fragBuilder->codeAppendf("\t\tfor (int i = 0; i < %d; i++) {\n", width());
    fragBuilder->codeAppendf("\t\t\t%s = %s(%s, ", args.fOutputColor, func, args.fOutputColor);
    fragBuilder->appendTextureLookup(args.fSamplers[0], "coord");
    fragBuilder->codeAppend(");\n");
    // coord.x += pixelSize;
    fragBuilder->codeAppendf("\t\t\tcoord.%s += %s;\n", dir, pixelSizeInc);
    if (fUseRange) {
        // coord.x = min(highBound, coord.x);
        fragBuilder->codeAppendf("\t\t\tcoord.%s = min(highBound, coord.%s);", dir, dir);
    }
    fragBuilder->codeAppend("\t\t}\n");
    SkString modulate;
    GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
    fragBuilder->codeAppend(modulate.c_str());
}

        void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
            const PLSFinishEffect& fe = args.fGP.cast<PLSFinishEffect>();
            GrGLSLVertexBuilder* vsBuilder = args.fVertBuilder;
            GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
            GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;

            fUseEvenOdd = uniformHandler->addUniform(kFragment_GrShaderFlag,
                                                    kFloat_GrSLType, kLow_GrSLPrecision, 
                                                    "useEvenOdd");
            const char* useEvenOdd = uniformHandler->getUniformCStr(fUseEvenOdd);

            varyingHandler->emitAttributes(fe);
            this->setupPosition(vsBuilder, gpArgs, fe.inPosition()->fName);
            this->emitTransforms(vsBuilder, varyingHandler, uniformHandler, gpArgs->fPositionVar, 
                                 fe.inPosition()->fName, fe.localMatrix(), args.fTransformsIn, 
                                 args.fTransformsOut);

            GrGLSLFragmentBuilder* fsBuilder = args.fFragBuilder;
            SkAssertResult(fsBuilder->enableFeature(
                           GrGLSLFragmentShaderBuilder::kPixelLocalStorage_GLSLFeature));
            fsBuilder->declAppendf(GR_GL_PLS_PATH_DATA_DECL);
            fsBuilder->codeAppend("float coverage;");
            fsBuilder->codeAppendf("if (%s != 0.0) {", useEvenOdd);
            fsBuilder->codeAppend("coverage = float(abs(pls.windings[0]) % 2) * 0.25;");
            fsBuilder->codeAppend("coverage += float(abs(pls.windings[1]) % 2) * 0.25;");
            fsBuilder->codeAppend("coverage += float(abs(pls.windings[2]) % 2) * 0.25;");
            fsBuilder->codeAppend("coverage += float(abs(pls.windings[3]) % 2) * 0.25;");
            fsBuilder->codeAppend("} else {");
            fsBuilder->codeAppend("coverage = pls.windings[0] != 0 ? 0.25 : 0.0;");
            fsBuilder->codeAppend("coverage += pls.windings[1] != 0 ? 0.25 : 0.0;");
            fsBuilder->codeAppend("coverage += pls.windings[2] != 0 ? 0.25 : 0.0;");
            fsBuilder->codeAppend("coverage += pls.windings[3] != 0 ? 0.25 : 0.0;");
            fsBuilder->codeAppend("}");
            if (!fe.colorIgnored()) {
                this->setupUniformColor(fsBuilder, uniformHandler, args.fOutputColor, 
                                        &fColorUniform);
            }
            fsBuilder->codeAppendf("%s = vec4(coverage);", args.fOutputCoverage);
            fsBuilder->codeAppendf("%s = vec4(1.0, 0.0, 1.0, 1.0);", args.fOutputColor);
        }

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

    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);

    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),
    };
    GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
    SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 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,
                                  domain,
                                  sampleVar.c_str(),
                                  coord,
                                  args.fSamplers[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);
    fragBuilder->codeAppendf("\t%s = %s;\n",
                             args.fOutputColor, (GrGLSLExpr4(bicubicColor.c_str()) *
                                                 GrGLSLExpr4(args.fInputColor)).c_str());
}