C++ GrGLSLVertexBuilder::codeAppendf方法代码示例

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

            // emit attributes
            varyingHandler->emitAttributes(qe);

            GrGLSLVertToFrag uv(kVec2f_GrSLType);
            varyingHandler->addVarying("uv", &uv, kHigh_GrSLPrecision);
            vsBuilder->codeAppendf("%s = %s;", uv.vsOut(), qe.inUV()->fName);

            GrGLSLVertToFrag ep1(kVec2f_GrSLType);
            varyingHandler->addVarying("endpoint1", &ep1, kHigh_GrSLPrecision);
            vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);", ep1.vsOut(), 
                                  qe.inEndpoint1()->fName, qe.inEndpoint1()->fName);

            GrGLSLVertToFrag ep2(kVec2f_GrSLType);
            varyingHandler->addVarying("endpoint2", &ep2, kHigh_GrSLPrecision);
            vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);", ep2.vsOut(), 
                                  qe.inEndpoint2()->fName, qe.inEndpoint2()->fName);

            GrGLSLVertToFrag delta(kVec2f_GrSLType);
            varyingHandler->addVarying("delta", &delta, kHigh_GrSLPrecision);
            vsBuilder->codeAppendf("%s = vec2(%s.x - %s.x, %s.y - %s.y) * 0.5;", 
                                   delta.vsOut(), ep1.vsOut(), ep2.vsOut(), ep2.vsOut(), 
                                   ep1.vsOut());

            GrGLSLVertToFrag windings(kInt_GrSLType);
            varyingHandler->addFlatVarying("windings", &windings, kLow_GrSLPrecision);
            vsBuilder->codeAppendf("%s = %s;", 
                                   windings.vsOut(), qe.inWindings()->fName);

            // Setup position
            this->setupPosition(vsBuilder, gpArgs, qe.inPosition()->fName);

            // emit transforms
            this->emitTransforms(vsBuilder, varyingHandler, uniformHandler, gpArgs->fPositionVar, 
                                 qe.inPosition()->fName, qe.localMatrix(), args.fTransformsIn, 
                                 args.fTransformsOut);

            GrGLSLFragmentBuilder* fsBuilder = args.fFragBuilder;
            SkAssertResult(fsBuilder->enableFeature(
                           GrGLSLFragmentShaderBuilder::kPixelLocalStorage_GLSLFeature));
            SkAssertResult(fsBuilder->enableFeature(
                    GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
            static const int QUAD_ARGS = 2;
            GrGLSLShaderVar inQuadArgs[QUAD_ARGS] = {
                GrGLSLShaderVar("dot", kFloat_GrSLType, 0, kHigh_GrSLPrecision),
                GrGLSLShaderVar("uv", kVec2f_GrSLType, 0, kHigh_GrSLPrecision)
            };
            SkString inQuadName;

            const char* inQuadCode = "if (uv.x * uv.x <= uv.y) {"
                                     "return dot >= 0.0;"
                                     "} else {"
                                     "return false;"
                                     "}";
            fsBuilder->emitFunction(kBool_GrSLType, "in_quad", QUAD_ARGS, inQuadArgs, inQuadCode, 
                                    &inQuadName);
            fsBuilder->declAppendf(GR_GL_PLS_PATH_DATA_DECL);
            // keep the derivative instructions outside the conditional
            fsBuilder->codeAppendf("highp vec2 uvdX = dFdx(%s);", uv.fsIn());
            fsBuilder->codeAppendf("highp vec2 uvdY = dFdy(%s);", uv.fsIn());
            fsBuilder->codeAppend("highp vec2 uvIncX = uvdX * 0.45 + uvdY * -0.1;");
            fsBuilder->codeAppend("highp vec2 uvIncY = uvdX * 0.1 + uvdY * 0.55;");
            fsBuilder->codeAppendf("highp vec2 uv = %s.xy - uvdX * 0.35 - uvdY * 0.25;", 
                                   uv.fsIn());
            fsBuilder->codeAppendf("highp vec2 firstSample = %s.xy - vec2(0.25);",
                                   fsBuilder->fragmentPosition());
            fsBuilder->codeAppendf("highp float d = dot(%s, (firstSample - %s).yx) * 2.0;", 
                                   delta.fsIn(), ep1.fsIn());
            fsBuilder->codeAppendf("pls.windings[0] += %s(d, uv) ? %s : 0;", inQuadName.c_str(), 
                                   windings.fsIn());
            fsBuilder->codeAppend("uv += uvIncX;");
            fsBuilder->codeAppendf("d += %s.x;", delta.fsIn());
            fsBuilder->codeAppendf("pls.windings[1] += %s(d, uv) ? %s : 0;", inQuadName.c_str(), 
                                   windings.fsIn());
            fsBuilder->codeAppend("uv += uvIncY;");
            fsBuilder->codeAppendf("d += %s.y;", delta.fsIn());
            fsBuilder->codeAppendf("pls.windings[2] += %s(d, uv) ? %s : 0;", inQuadName.c_str(), 
                                   windings.fsIn());
            fsBuilder->codeAppend("uv -= uvIncX;");
            fsBuilder->codeAppendf("d -= %s.x;", delta.fsIn());
            fsBuilder->codeAppendf("pls.windings[3] += %s(d, uv) ? %s : 0;", inQuadName.c_str(), 
                                   windings.fsIn());
        }

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

        GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
        GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
        GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;

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

        // compute numbers to be hardcoded to convert texture coordinates from int to float
        SkASSERT(cte.numTextures() == 1);
        SkDEBUGCODE(GrTexture* atlas = cte.textureAccess(0).getTexture());
        SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));

        GrGLSLVertToFrag v(kVec2f_GrSLType);
        varyingHandler->addVarying("TextureCoords", &v, kHigh_GrSLPrecision);
        vertBuilder->codeAppendf("%s = %s;", v.vsOut(),
                                 cte.inTextureCoords()->fName);

        GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
        // Setup pass through color
        if (!cte.colorIgnored()) {
            if (cte.hasVertexColor()) {
                varyingHandler->addPassThroughAttribute(cte.inColor(), args.fOutputColor);
            } else {
                this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor,
                                        &fColorUniform);
            }
        }

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

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

        if (cte.maskFormat() == kARGB_GrMaskFormat) {
            fragBuilder->codeAppendf("%s = ", args.fOutputColor);
            fragBuilder->appendTextureLookupAndModulate(args.fOutputColor,
                                                        args.fTexSamplers[0],
                                                        v.fsIn(),
                                                        kVec2f_GrSLType);
            fragBuilder->codeAppend(";");
            fragBuilder->codeAppendf("%s = vec4(1);", args.fOutputCoverage);
        } else {
            fragBuilder->codeAppendf("%s = ", args.fOutputCoverage);
            fragBuilder->appendTextureLookup(args.fTexSamplers[0], v.fsIn(), kVec2f_GrSLType);
            fragBuilder->codeAppend(";");
            if (cte.maskFormat() == kA565_GrMaskFormat) {
                // set alpha to be max of rgb coverage
                fragBuilder->codeAppendf("%s.a = max(max(%s.r, %s.g), %s.b);",
                                         args.fOutputCoverage, args.fOutputCoverage,
                                         args.fOutputCoverage, args.fOutputCoverage);
            }
        }
    }

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

        GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
        GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
        GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;

        // emit attributes
        varyingHandler->emitAttributes(dfTexEffect);

        GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;

        // setup pass through color
        if (!dfTexEffect.colorIgnored()) {
            varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
        }

        // Setup position
        this->setupPosition(vertBuilder,
                            uniformHandler,
                            gpArgs,
                            dfTexEffect.inPosition()->fName,
                            dfTexEffect.viewMatrix(),
                            &fViewMatrixUniform);

        // emit transforms
        this->emitTransforms(vertBuilder,
                             varyingHandler,
                             uniformHandler,
                             gpArgs->fPositionVar,
                             dfTexEffect.inPosition()->fName,
                             args.fTransformsIn,
                             args.fTransformsOut);

        // set up varyings
        bool isUniformScale = SkToBool(dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask);
        GrGLSLVertToFrag recipScale(kFloat_GrSLType);
        GrGLSLVertToFrag st(kVec2f_GrSLType);
        varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
        vertBuilder->codeAppendf("%s = %s;", st.vsOut(), dfTexEffect.inTextureCoords()->fName);

        // compute numbers to be hardcoded to convert texture coordinates from int to float
        SkASSERT(dfTexEffect.numTextures() == 1);
        GrTexture* atlas = dfTexEffect.textureAccess(0).getTexture();
        SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
        SkScalar recipWidth = 1.0f / atlas->width();
        SkScalar recipHeight = 1.0f / atlas->height();

        GrGLSLVertToFrag uv(kVec2f_GrSLType);
        varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
        vertBuilder->codeAppendf("%s = vec2(%.*f, %.*f) * %s;", uv.vsOut(),
                                 GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipWidth,
                                 GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipHeight,
                                 dfTexEffect.inTextureCoords()->fName);

        // add frag shader code

        SkAssertResult(fragBuilder->enableFeature(
                GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));

        // create LCD offset adjusted by inverse of transform
        // Use highp to work around aliasing issues
        fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
                                                                 kHigh_GrSLPrecision));
        fragBuilder->codeAppendf("vec2 uv = %s;\n", uv.fsIn());
        fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
                                                                 kHigh_GrSLPrecision));

        SkScalar lcdDelta = 1.0f / (3.0f * atlas->width());
        if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
            fragBuilder->codeAppendf("float delta = -%.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
        } else {
            fragBuilder->codeAppendf("float delta = %.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
        }
        if (isUniformScale) {
            fragBuilder->codeAppendf("float dy = abs(dFdy(%s.y));", st.fsIn());
            fragBuilder->codeAppend("vec2 offset = vec2(dy*delta, 0.0);");
        } else {
            fragBuilder->codeAppendf("vec2 st = %s;\n", st.fsIn());

            fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
            fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
            fragBuilder->codeAppend("vec2 offset = delta*Jdx;");
        }

        // green is distance to uv center
        fragBuilder->codeAppend("\tvec4 texColor = ");
        fragBuilder->appendTextureLookup(args.fSamplers[0], "uv", kVec2f_GrSLType);
        fragBuilder->codeAppend(";\n");
        fragBuilder->codeAppend("\tvec3 distance;\n");
        fragBuilder->codeAppend("\tdistance.y = texColor.r;\n");
        // red is distance to left offset
        fragBuilder->codeAppend("\tvec2 uv_adjusted = uv - offset;\n");
        fragBuilder->codeAppend("\ttexColor = ");
        fragBuilder->appendTextureLookup(args.fSamplers[0], "uv_adjusted", kVec2f_GrSLType);
        fragBuilder->codeAppend(";\n");
        fragBuilder->codeAppend("\tdistance.x = texColor.r;\n");
        // blue is distance to right offset
        fragBuilder->codeAppend("\tuv_adjusted = uv + offset;\n");
//.........这里部分代码省略.........

void GLSLPathProcessor::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
    using InstanceAttribs = GrCCPRPathProcessor::InstanceAttribs;
    const GrCCPRPathProcessor& proc = args.fGP.cast<GrCCPRPathProcessor>();
    GrGLSLUniformHandler* uniHandler = args.fUniformHandler;
    GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;

    const char* atlasAdjust;
    fAtlasAdjustUniform = uniHandler->addUniform(
            kVertex_GrShaderFlag,
            kVec2f_GrSLType, kHigh_GrSLPrecision, "atlas_adjust", &atlasAdjust);

    varyingHandler->emitAttributes(proc);

    GrGLSLVertToFrag texcoord(kVec2f_GrSLType);
    GrGLSLVertToFrag color(kVec4f_GrSLType);
    varyingHandler->addVarying("texcoord", &texcoord, kHigh_GrSLPrecision);
    varyingHandler->addFlatPassThroughAttribute(&proc.getInstanceAttrib(InstanceAttribs::kColor),
                                                args.fOutputColor, kLow_GrSLPrecision);

    // Vertex shader.
    GrGLSLVertexBuilder* v = args.fVertBuilder;

    // Find the intersections of (bloated) devBounds and devBounds45 in order to come up with an
    // octagon that circumscribes the (bloated) path. A vertex is the intersection of two lines:
    // one edge from the path's bounding box and one edge from its 45-degree bounding box.
    v->codeAppendf("highp mat2 N = mat2(%s);", proc.getEdgeNormsAttrib().fName);

    // N[0] is the normal for the edge we are intersecting from the regular bounding box, pointing
    // out of the octagon.
    v->codeAppendf("highp vec2 refpt = (min(N[0].x, N[0].y) < 0) ? %s.xy : %s.zw;",
                   proc.getInstanceAttrib(InstanceAttribs::kDevBounds).fName,
                   proc.getInstanceAttrib(InstanceAttribs::kDevBounds).fName);
    v->codeAppendf("refpt += N[0] * %f;", kAABloatRadius); // bloat for AA.

    // N[1] is the normal for the edge we are intersecting from the 45-degree bounding box, pointing
    // out of the octagon.
    v->codeAppendf("highp vec2 refpt45 = (N[1].x < 0) ? %s.xy : %s.zw;",
                   proc.getInstanceAttrib(InstanceAttribs::kDevBounds45).fName,
                   proc.getInstanceAttrib(InstanceAttribs::kDevBounds45).fName);
    v->codeAppendf("refpt45 *= mat2(.5,.5,-.5,.5);"); // transform back to device space.
    v->codeAppendf("refpt45 += N[1] * %f;", kAABloatRadius); // bloat for AA.

    v->codeAppend ("highp vec2 K = vec2(dot(N[0], refpt), dot(N[1], refpt45));");
    v->codeAppendf("highp vec2 octocoord = K * inverse(N);");

    gpArgs->fPositionVar.set(kVec2f_GrSLType, "octocoord");

    // Convert to atlas coordinates in order to do our texture lookup.
    v->codeAppendf("highp vec2 atlascoord = octocoord + vec2(%s);",
                   proc.getInstanceAttrib(InstanceAttribs::kAtlasOffset).fName);
    if (kTopLeft_GrSurfaceOrigin == proc.atlas()->origin()) {
        v->codeAppendf("%s = atlascoord * %s;", texcoord.vsOut(), atlasAdjust);
    } else {
        SkASSERT(kBottomLeft_GrSurfaceOrigin == proc.atlas()->origin());
        v->codeAppendf("%s = vec2(atlascoord.x * %s.x, 1 - atlascoord.y * %s.y);",
                       texcoord.vsOut(), atlasAdjust, atlasAdjust);
    }

    // Convert to (local) path cordinates.
    v->codeAppendf("highp vec2 pathcoord = inverse(mat2(%s)) * (octocoord - %s);",
                   proc.getInstanceAttrib(InstanceAttribs::kViewMatrix).fName,
                   proc.getInstanceAttrib(InstanceAttribs::kViewTranslate).fName);

    this->emitTransforms(v, varyingHandler, uniHandler, gpArgs->fPositionVar, "pathcoord",
                         args.fFPCoordTransformHandler);

    // Fragment shader.
    GrGLSLPPFragmentBuilder* f = args.fFragBuilder;

    f->codeAppend ("mediump float coverage_count = ");
    f->appendTextureLookup(args.fTexSamplers[0], texcoord.fsIn(), kVec2f_GrSLType);
    f->codeAppend (".a;");

    if (SkPath::kWinding_FillType == proc.fillType()) {
        f->codeAppendf("%s = vec4(min(abs(coverage_count), 1));", args.fOutputCoverage);
    } else {
        SkASSERT(SkPath::kEvenOdd_FillType == proc.fillType());
        f->codeAppend ("mediump float t = mod(abs(coverage_count), 2);");
        f->codeAppendf("%s = vec4(1 - abs(t - 1));", args.fOutputCoverage);
    }
}

void GrGLCubicEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
    GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
    const GrCubicEffect& gp = args.fGP.cast<GrCubicEffect>();
    GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
    GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;

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

    GrGLSLVertToFrag v(kVec4f_GrSLType);
    varyingHandler->addVarying("CubicCoeffs", &v, kHigh_GrSLPrecision);
    vertBuilder->codeAppendf("%s = %s;", v.vsOut(), gp.inCubicCoeffs()->fName);

    GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
    // Setup pass through color
    if (!gp.colorIgnored()) {
        this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor, &fColorUniform);
    }

    // Setup position
    this->setupPosition(vertBuilder,
                        uniformHandler,
                        gpArgs,
                        gp.inPosition()->fName,
                        gp.viewMatrix(),
                        &fViewMatrixUniform);

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


    GrGLSLShaderVar edgeAlpha("edgeAlpha", kFloat_GrSLType, 0, kHigh_GrSLPrecision);
    GrGLSLShaderVar dklmdx("dklmdx", kVec3f_GrSLType, 0, kHigh_GrSLPrecision);
    GrGLSLShaderVar dklmdy("dklmdy", kVec3f_GrSLType, 0, kHigh_GrSLPrecision);
    GrGLSLShaderVar dfdx("dfdx", kFloat_GrSLType, 0, kHigh_GrSLPrecision);
    GrGLSLShaderVar dfdy("dfdy", kFloat_GrSLType, 0, kHigh_GrSLPrecision);
    GrGLSLShaderVar gF("gF", kVec2f_GrSLType, 0, kHigh_GrSLPrecision);
    GrGLSLShaderVar gFM("gFM", kFloat_GrSLType, 0, kHigh_GrSLPrecision);
    GrGLSLShaderVar func("func", kFloat_GrSLType, 0, kHigh_GrSLPrecision);

    fragBuilder->declAppend(edgeAlpha);
    fragBuilder->declAppend(dklmdx);
    fragBuilder->declAppend(dklmdy);
    fragBuilder->declAppend(dfdx);
    fragBuilder->declAppend(dfdy);
    fragBuilder->declAppend(gF);
    fragBuilder->declAppend(gFM);
    fragBuilder->declAppend(func);

    switch (fEdgeType) {
        case kHairlineAA_GrProcessorEdgeType: {
            SkAssertResult(fragBuilder->enableFeature(
                    GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
            fragBuilder->codeAppendf("%s = dFdx(%s.xyz);", dklmdx.c_str(), v.fsIn());
            fragBuilder->codeAppendf("%s = dFdy(%s.xyz);", dklmdy.c_str(), v.fsIn());
            fragBuilder->codeAppendf("%s = 3.0 * %s.x * %s.x * %s.x - %s.y * %s.z - %s.z * %s.y;",
                                     dfdx.c_str(), v.fsIn(), v.fsIn(), dklmdx.c_str(), v.fsIn(),
                                     dklmdx.c_str(), v.fsIn(), dklmdx.c_str());
            fragBuilder->codeAppendf("%s = 3.0 * %s.x * %s.x * %s.x - %s.y * %s.z - %s.z * %s.y;",
                                     dfdy.c_str(), v.fsIn(), v.fsIn(), dklmdy.c_str(), v.fsIn(),
                                     dklmdy.c_str(), v.fsIn(), dklmdy.c_str());
            fragBuilder->codeAppendf("%s = vec2(%s, %s);", gF.c_str(), dfdx.c_str(), dfdy.c_str());
            fragBuilder->codeAppendf("%s = sqrt(dot(%s, %s));",
                                     gFM.c_str(), gF.c_str(), gF.c_str());
            fragBuilder->codeAppendf("%s = %s.x * %s.x * %s.x - %s.y * %s.z;",
                                     func.c_str(), v.fsIn(), v.fsIn(),
                                     v.fsIn(), v.fsIn(), v.fsIn());
            fragBuilder->codeAppendf("%s = abs(%s);", func.c_str(), func.c_str());
            fragBuilder->codeAppendf("%s = %s / %s;",
                                     edgeAlpha.c_str(), func.c_str(), gFM.c_str());
            fragBuilder->codeAppendf("%s = max(1.0 - %s, 0.0);",
                                     edgeAlpha.c_str(), edgeAlpha.c_str());
            // Add line below for smooth cubic ramp
            // fragBuilder->codeAppendf("%s = %s * %s * (3.0 - 2.0 * %s);",
            //                        edgeAlpha.c_str(), edgeAlpha.c_str(), edgeAlpha.c_str(),
            //                        edgeAlpha.c_str());
            break;
        }
        case kFillAA_GrProcessorEdgeType: {
            SkAssertResult(fragBuilder->enableFeature(
                    GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
            fragBuilder->codeAppendf("%s = dFdx(%s.xyz);", dklmdx.c_str(), v.fsIn());
            fragBuilder->codeAppendf("%s = dFdy(%s.xyz);", dklmdy.c_str(), v.fsIn());
            fragBuilder->codeAppendf("%s ="
                                     "3.0 * %s.x * %s.x * %s.x - %s.y * %s.z - %s.z * %s.y;",
                                     dfdx.c_str(), v.fsIn(), v.fsIn(), dklmdx.c_str(), v.fsIn(),
                                     dklmdx.c_str(), v.fsIn(), dklmdx.c_str());
            fragBuilder->codeAppendf("%s = 3.0 * %s.x * %s.x * %s.x - %s.y * %s.z - %s.z * %s.y;",
                                     dfdy.c_str(), v.fsIn(), v.fsIn(), dklmdy.c_str(), v.fsIn(),
                                     dklmdy.c_str(), v.fsIn(), dklmdy.c_str());
            fragBuilder->codeAppendf("%s = vec2(%s, %s);", gF.c_str(), dfdx.c_str(), dfdy.c_str());
            fragBuilder->codeAppendf("%s = sqrt(dot(%s, %s));",
                                     gFM.c_str(), gF.c_str(), gF.c_str());
            fragBuilder->codeAppendf("%s = %s.x * %s.x * %s.x - %s.y * %s.z;",
//.........这里部分代码省略.........

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

        GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
        GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
        GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;

        // emit attributes
        varyingHandler->emitAttributes(dfTexEffect);

        GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;

        // setup pass through color
        if (!dfTexEffect.colorIgnored()) {
            varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
        }

        // Setup position
        this->setupPosition(vertBuilder,
                            uniformHandler,
                            gpArgs,
                            dfTexEffect.inPosition()->fName,
                            dfTexEffect.viewMatrix(),
                            &fViewMatrixUniform);

        // emit transforms
        this->emitTransforms(vertBuilder,
                             varyingHandler,
                             uniformHandler,
                             gpArgs->fPositionVar,
                             dfTexEffect.inPosition()->fName,
                             args.fFPCoordTransformHandler);

        // set up varyings
        bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
                              kUniformScale_DistanceFieldEffectMask;
        bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
        bool isGammaCorrect =
            SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
        GrGLSLVertToFrag recipScale(kFloat_GrSLType);
        GrGLSLVertToFrag uv(kVec2f_GrSLType);
        varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
        vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);

        // compute numbers to be hardcoded to convert texture coordinates from float to int
        SkASSERT(dfTexEffect.numTextures() == 1);
        GrTexture* atlas = dfTexEffect.textureAccess(0).getTexture();
        SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));

        GrGLSLVertToFrag st(kVec2f_GrSLType);
        varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
        vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
                                 atlas->width(), atlas->height(),
                                 dfTexEffect.inTextureCoords()->fName);

        // add frag shader code

        SkAssertResult(fragBuilder->enableFeature(
                GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));

        // create LCD offset adjusted by inverse of transform
        // Use highp to work around aliasing issues
        fragBuilder->appendPrecisionModifier(kHigh_GrSLPrecision);
        fragBuilder->codeAppendf("vec2 uv = %s;\n", uv.fsIn());
        fragBuilder->appendPrecisionModifier(kHigh_GrSLPrecision);

        SkScalar lcdDelta = 1.0f / (3.0f * atlas->width());
        if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
            fragBuilder->codeAppendf("float delta = -%.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
        } else {
            fragBuilder->codeAppendf("float delta = %.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
        }
        if (isUniformScale) {
#ifdef SK_VULKAN
            fragBuilder->codeAppendf("float st_grad_len = abs(dFdx(%s.x));", st.fsIn());
#else
            // We use the y gradient because there is a bug in the Mali 400 in the x direction.
            fragBuilder->codeAppendf("float st_grad_len = abs(dFdy(%s.y));", st.fsIn());
#endif
            fragBuilder->codeAppend("vec2 offset = vec2(st_grad_len*delta, 0.0);");
        } else if (isSimilarity) {
            // For a similarity matrix with rotation, the gradient will not be aligned
            // with the texel coordinate axes, so we need to calculate it.
#ifdef SK_VULKAN
            fragBuilder->codeAppendf("vec2 st_grad = dFdx(%s);", st.fsIn());
            fragBuilder->codeAppend("vec2 offset = delta*st_grad;");
#else
            // We use dFdy because of a Mali 400 bug, and rotate -90 degrees to
            // get the gradient in the x direction.
            fragBuilder->codeAppendf("vec2 st_grad = dFdy(%s);", st.fsIn());
            fragBuilder->codeAppend("vec2 offset = delta*vec2(st_grad.y, -st_grad.x);");
#endif
            fragBuilder->codeAppend("float st_grad_len = length(st_grad);");
        } else {
            fragBuilder->codeAppendf("vec2 st = %s;\n", st.fsIn());

            fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
            fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
            fragBuilder->codeAppend("vec2 offset = delta*Jdx;");
//.........这里部分代码省略.........

void GrGLCubicEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
    GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
    const GrCubicEffect& gp = args.fGP.cast<GrCubicEffect>();
    GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
    GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;

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

    GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
    // Setup pass through color
    if (!gp.colorIgnored()) {
        this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor, &fColorUniform);
    }

    // Setup position
    this->setupPosition(vertBuilder,
                        uniformHandler,
                        gpArgs,
                        gp.inPosition()->fName,
                        gp.viewMatrix(),
                        &fViewMatrixUniform);

    // Setup KLM
    const char* devkLMMatrixName;
    fDevKLMUniform = uniformHandler->addUniform(kVertex_GrShaderFlag, kMat33f_GrSLType,
                                                kHigh_GrSLPrecision, "KLM", &devkLMMatrixName);
    GrGLSLVertToFrag v(kVec3f_GrSLType);
    varyingHandler->addVarying("CubicCoeffs", &v, kHigh_GrSLPrecision);
    vertBuilder->codeAppendf("%s = %s * vec3(%s, 1);",
                             v.vsOut(), devkLMMatrixName, gpArgs->fPositionVar.c_str());


    GrGLSLVertToFrag gradCoeffs(kVec4f_GrSLType);
    if (kFillAA_GrProcessorEdgeType == fEdgeType || kHairlineAA_GrProcessorEdgeType == fEdgeType) {
        varyingHandler->addVarying("GradCoeffs", &gradCoeffs, kHigh_GrSLPrecision);
        vertBuilder->codeAppendf("highp float k = %s[0], l = %s[1], m = %s[2];",
                                 v.vsOut(), v.vsOut(), v.vsOut());
        vertBuilder->codeAppendf("highp vec2 gk = vec2(%s[0][0], %s[1][0]), "
                                            "gl = vec2(%s[0][1], %s[1][1]), "
                                            "gm = vec2(%s[0][2], %s[1][2]);",
                                 devkLMMatrixName, devkLMMatrixName, devkLMMatrixName,
                                 devkLMMatrixName, devkLMMatrixName, devkLMMatrixName);
        vertBuilder->codeAppendf("%s = vec4(3 * k * gk, -m * gl - l * gm);",
                                 gradCoeffs.vsOut());
    }

    // emit transforms with position
    this->emitTransforms(vertBuilder,
                         varyingHandler,
                         uniformHandler,
                         gpArgs->fPositionVar,
                         gp.inPosition()->fName,
                         args.fFPCoordTransformHandler);


    GrShaderVar edgeAlpha("edgeAlpha", kFloat_GrSLType, 0, kHigh_GrSLPrecision);
    GrShaderVar gF("gF", kVec2f_GrSLType, 0, kHigh_GrSLPrecision);
    GrShaderVar func("func", kFloat_GrSLType, 0, kHigh_GrSLPrecision);

    fragBuilder->declAppend(edgeAlpha);
    fragBuilder->declAppend(gF);
    fragBuilder->declAppend(func);

    switch (fEdgeType) {
        case kHairlineAA_GrProcessorEdgeType: {
            fragBuilder->codeAppendf("%s = %s.x * %s.xy + %s.zw;",
                                     gF.c_str(), v.fsIn(), gradCoeffs.fsIn(), gradCoeffs.fsIn());
            fragBuilder->codeAppendf("%s = %s.x * %s.x * %s.x - %s.y * %s.z;",
                                     func.c_str(), v.fsIn(), v.fsIn(),
                                     v.fsIn(), v.fsIn(), v.fsIn());
            fragBuilder->codeAppendf("%s = abs(%s);", func.c_str(), func.c_str());
            fragBuilder->codeAppendf("%s = %s * inversesqrt(dot(%s, %s));",
                                     edgeAlpha.c_str(), func.c_str(), gF.c_str(), gF.c_str());
            fragBuilder->codeAppendf("%s = max(1.0 - %s, 0.0);",
                                     edgeAlpha.c_str(), edgeAlpha.c_str());
            // Add line below for smooth cubic ramp
            // fragBuilder->codeAppendf("%s = %s * %s * (3.0 - 2.0 * %s);",
            //                        edgeAlpha.c_str(), edgeAlpha.c_str(), edgeAlpha.c_str(),
            //                        edgeAlpha.c_str());
            break;
        }
        case kFillAA_GrProcessorEdgeType: {
            fragBuilder->codeAppendf("%s = %s.x * %s.xy + %s.zw;",
                                     gF.c_str(), v.fsIn(), gradCoeffs.fsIn(), gradCoeffs.fsIn());
            fragBuilder->codeAppendf("%s = %s.x * %s.x * %s.x - %s.y * %s.z;",
                                     func.c_str(),
                                     v.fsIn(), v.fsIn(), v.fsIn(), v.fsIn(), v.fsIn());
            fragBuilder->codeAppendf("%s = %s * inversesqrt(dot(%s, %s));",
                                     edgeAlpha.c_str(), func.c_str(), gF.c_str(), gF.c_str());
            fragBuilder->codeAppendf("%s = clamp(0.5 - %s, 0.0, 1.0);",
                                     edgeAlpha.c_str(), edgeAlpha.c_str());
            // Add line below for smooth cubic ramp
            // fragBuilder->codeAppendf("%s = %s * %s * (3.0 - 2.0 * %s);",
            //                        edgeAlpha.c_str(), edgeAlpha.c_str(), edgeAlpha.c_str(),
            //                        edgeAlpha.c_str());
            break;
        }
        case kFillBW_GrProcessorEdgeType: {
            fragBuilder->codeAppendf("%s = %s.x * %s.x * %s.x - %s.y * %s.z;",
//.........这里部分代码省略.........

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

        GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
        GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
        GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;

        // emit attributes
        varyingHandler->emitAttributes(dfTexEffect);

        const char* atlasSizeInvName;
        fAtlasSizeInvUniform = uniformHandler->addUniform(kVertex_GrShaderFlag,
                                                          kFloat2_GrSLType,
                                                          kHigh_GrSLPrecision,
                                                          "AtlasSizeInv",
                                                          &atlasSizeInvName);

        GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;

        // setup pass through color
        varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);

        // Setup position
        gpArgs->fPositionVar = dfTexEffect.inPosition()->asShaderVar();

        // emit transforms
        this->emitTransforms(vertBuilder,
                             varyingHandler,
                             uniformHandler,
                             dfTexEffect.inPosition()->asShaderVar(),
                             dfTexEffect.localMatrix(),
                             args.fFPCoordTransformHandler);

        // set up varyings
        GrGLSLVarying uv(kFloat2_GrSLType);
        GrSLType texIdxType = args.fShaderCaps->integerSupport() ? kInt_GrSLType : kFloat_GrSLType;
        GrGLSLVarying texIdx(texIdxType);
        GrGLSLVarying st(kFloat2_GrSLType);
        append_index_uv_varyings(args, dfTexEffect.inTextureCoords()->fName, atlasSizeInvName,
                                 &uv, &texIdx, &st);

        GrGLSLVarying delta(kFloat_GrSLType);
        varyingHandler->addVarying("Delta", &delta);
        if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
            vertBuilder->codeAppendf("%s = -%s.x/3.0;", delta.vsOut(), atlasSizeInvName);
        } else {
            vertBuilder->codeAppendf("%s = %s.x/3.0;", delta.vsOut(), atlasSizeInvName);
        }

        // add frag shader code
        bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
                              kUniformScale_DistanceFieldEffectMask;
        bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
        bool isGammaCorrect =
            SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);

        // create LCD offset adjusted by inverse of transform
        // Use highp to work around aliasing issues
        fragBuilder->codeAppendf("float2 uv = %s;\n", uv.fsIn());

        if (isUniformScale) {
#ifdef SK_VULKAN
            fragBuilder->codeAppendf("half st_grad_len = abs(dFdx(%s.x));", st.fsIn());
#else
            // We use the y gradient because there is a bug in the Mali 400 in the x direction.
            fragBuilder->codeAppendf("half st_grad_len = abs(dFdy(%s.y));", st.fsIn());
#endif
            fragBuilder->codeAppendf("half2 offset = half2(st_grad_len*%s, 0.0);", delta.fsIn());
        } else if (isSimilarity) {
            // For a similarity matrix with rotation, the gradient will not be aligned
            // with the texel coordinate axes, so we need to calculate it.
#ifdef SK_VULKAN
            fragBuilder->codeAppendf("half2 st_grad = dFdx(%s);", st.fsIn());
            fragBuilder->codeAppendf("half2 offset = %s*st_grad;", delta.fsIn());
#else
            // We use dFdy because of a Mali 400 bug, and rotate -90 degrees to
            // get the gradient in the x direction.
            fragBuilder->codeAppendf("half2 st_grad = dFdy(%s);", st.fsIn());
            fragBuilder->codeAppendf("half2 offset = %s*half2(st_grad.y, -st_grad.x);",
                                     delta.fsIn());
#endif
            fragBuilder->codeAppend("half st_grad_len = length(st_grad);");
        } else {
            fragBuilder->codeAppendf("half2 st = %s;\n", st.fsIn());

            fragBuilder->codeAppend("half2 Jdx = dFdx(st);");
            fragBuilder->codeAppend("half2 Jdy = dFdy(st);");
            fragBuilder->codeAppendf("half2 offset = %s*Jdx;", delta.fsIn());
        }

        // sample the texture by index
        fragBuilder->codeAppend("half4 texColor;");
        append_multitexture_lookup(args, dfTexEffect.numTextureSamplers(),
                                   texIdx, "uv", "texColor");

        // green is distance to uv center
        fragBuilder->codeAppend("half3 distance;");
        fragBuilder->codeAppend("distance.y = texColor.r;");
        // red is distance to left offset
//.........这里部分代码省略.........

    void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
        const auto& proc = args.fGP.cast<Processor>();
        bool useHWDerivatives = (proc.fFlags & Flags::kUseHWDerivatives);
        bool hasPerspective = (proc.fFlags & Flags::kHasPerspective);
        bool hasLocalCoords = (proc.fFlags & Flags::kHasLocalCoords);
        SkASSERT(useHWDerivatives == hasPerspective);

        SkASSERT(proc.vertexStride() == sizeof(MSAAVertex));

        // Emit the vertex shader.
        GrGLSLVertexBuilder* v = args.fVertBuilder;

        GrGLSLVaryingHandler* varyings = args.fVaryingHandler;
        varyings->emitAttributes(proc);
        varyings->addPassThroughAttribute(*proc.fColorAttrib, args.fOutputColor,
                                          GrGLSLVaryingHandler::Interpolation::kCanBeFlat);

        // Unpack vertex attribs.
        v->codeAppendf("float2 corner = corner_and_radius_outsets.xy;");
        v->codeAppendf("float2 radius_outset = corner_and_radius_outsets.zw;");

        // Identify our radii.
        v->codeAppend("float2 radii;");
        v->codeAppend("radii.x = dot(radii_selector, radii_x);");
        v->codeAppend("radii.y = dot(radii_selector, radii_y);");
        v->codeAppendf("bool is_arc_section = (radii.x > 0);");
        v->codeAppendf("radii = abs(radii);");

        // Find our vertex position, adjusted for radii. Our rect is drawn in normalized
        // [-1,-1,+1,+1] space.
        v->codeAppend("float2 vertexpos = corner + radius_outset * radii;");

        // Emit transforms.
        GrShaderVar localCoord("", kFloat2_GrSLType);
        if (hasLocalCoords) {
            v->codeAppend("float2 localcoord = (local_rect.xy * (1 - vertexpos) + "
                                               "local_rect.zw * (1 + vertexpos)) * .5;");
            localCoord.set(kFloat2_GrSLType, "localcoord");
        }
        this->emitTransforms(v, varyings, args.fUniformHandler, localCoord,
                             args.fFPCoordTransformHandler);

        // Transform to device space.
        if (!hasPerspective) {
            v->codeAppend("float2x2 skewmatrix = float2x2(skew.xy, skew.zw);");
            v->codeAppend("float2 devcoord = vertexpos * skewmatrix + translate;");
            gpArgs->fPositionVar.set(kFloat2_GrSLType, "devcoord");
        } else {
            v->codeAppend("float3x3 persp_matrix = float3x3(persp_x, persp_y, persp_z);");
            v->codeAppend("float3 devcoord = float3(vertexpos, 1) * persp_matrix;");
            gpArgs->fPositionVar.set(kFloat3_GrSLType, "devcoord");
        }

        // Determine normalized arc coordinates for the implicit function.
        GrGLSLVarying arcCoord((useHWDerivatives) ? kFloat2_GrSLType : kFloat4_GrSLType);
        varyings->addVarying("arccoord", &arcCoord);
        v->codeAppendf("if (is_arc_section) {");
        v->codeAppendf(    "%s.xy = 1 - abs(radius_outset);", arcCoord.vsOut());
        if (!useHWDerivatives) {
            // The gradient is order-1: Interpolate it across arccoord.zw.
            // This doesn't work with perspective.
            SkASSERT(!hasPerspective);
            v->codeAppendf("float2x2 derivatives = inverse(skewmatrix);");
            v->codeAppendf("%s.zw = derivatives * (%s.xy/radii * corner * 2);",
                           arcCoord.vsOut(), arcCoord.vsOut());
        }
        v->codeAppendf("} else {");
        if (useHWDerivatives) {
            v->codeAppendf("%s = float2(0);", arcCoord.vsOut());
        } else {
            v->codeAppendf("%s = float4(0);", arcCoord.vsOut());
        }
        v->codeAppendf("}");

        // Emit the fragment shader.
        GrGLSLFPFragmentBuilder* f = args.fFragBuilder;

        f->codeAppendf("%s = half4(1);", args.fOutputCoverage);

        // If x,y == 0, then we are drawing a triangle that does not track an arc.
        f->codeAppendf("if (float2(0) != %s.xy) {", arcCoord.fsIn());
        f->codeAppendf(    "float fn = dot(%s.xy, %s.xy) - 1;", arcCoord.fsIn(), arcCoord.fsIn());
        if (GrAAType::kMSAA == proc.fAAType) {
            using ScopeFlags = GrGLSLFPFragmentBuilder::ScopeFlags;
            if (!useHWDerivatives) {
                f->codeAppendf("float2 grad = %s.zw;", arcCoord.fsIn());
                f->applyFnToMultisampleMask("fn", "grad", ScopeFlags::kInsidePerPrimitiveBranch);
            } else {
                f->applyFnToMultisampleMask("fn", nullptr, ScopeFlags::kInsidePerPrimitiveBranch);
            }
        } else {
            f->codeAppendf("if (fn > 0) {");
            f->codeAppendf(    "%s = half4(0);", args.fOutputCoverage);
            f->codeAppendf("}");
        }
        f->codeAppendf("}");
    }