src/gpu/GrOvalRenderer.cpp

/*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrOvalRenderer.h"

#include "GrBatchFlushState.h"
#include "GrBatchTest.h"
#include "GrGeometryProcessor.h"
#include "GrInvariantOutput.h"
#include "GrProcessor.h"
#include "GrResourceProvider.h"
#include "GrStyle.h"
#include "SkRRect.h"
#include "SkStrokeRec.h"
#include "batches/GrVertexBatch.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"
#include "glsl/GrGLSLGeometryProcessor.h"
#include "glsl/GrGLSLProgramDataManager.h"
#include "glsl/GrGLSLVarying.h"
#include "glsl/GrGLSLVertexShaderBuilder.h"
#include "glsl/GrGLSLUniformHandler.h"
#include "glsl/GrGLSLUtil.h"

// TODO(joshualitt) - Break this file up during GrBatch post implementation cleanup

namespace {

struct EllipseVertex {
    SkPoint  fPos;
    GrColor  fColor;
    SkPoint  fOffset;
    SkPoint  fOuterRadii;
    SkPoint  fInnerRadii;
};

struct DIEllipseVertex {
    SkPoint  fPos;
    GrColor  fColor;
    SkPoint  fOuterOffset;
    SkPoint  fInnerOffset;
};

inline bool circle_stays_circle(const SkMatrix& m) {
    return m.isSimilarity();
}

}

///////////////////////////////////////////////////////////////////////////////

/**
 * The output of this effect is a modulation of the input color and coverage for a circle. It
 * operates in a space normalized by the circle radius (outer radius in the case of a stroke)
 * with origin at the circle center. Three vertex attributes are used:
 *    vec2f : position in device space of the bounding geometry vertices
 *    vec4ub: color
 *    vec4f : (p.xy, outerRad, innerRad)
 *             p is the position in the normalized space.
 *             outerRad is the outerRadius in device space.
 *             innerRad is the innerRadius in normalized space (ignored if not stroking).
 * If fUsesDistanceVectorField is set in fragment processors in the same program, then 
 * an additional vertex attribute is available via args.fFragBuilder->distanceVectorName():
 *    vec4f : (v.xy, outerDistance, innerDistance)
 *             v is a normalized vector pointing to the outer edge
 *             outerDistance is the distance to the outer edge, < 0 if we are outside of the shape
 *             if stroking, innerDistance is the distance to the inner edge, < 0 if outside
 * Additional clip planes are supported for rendering circular arcs. The additional planes are
 * either intersected or unioned together. Up to three planes are supported (an initial plane,
 * a plane intersected with the initial plane, and a plane unioned with the first two). Only two
 * are useful for any given arc, but having all three in one instance allows batching different
 * types of arcs.
 */

class CircleGeometryProcessor : public GrGeometryProcessor {
public:
    CircleGeometryProcessor(bool stroke, bool clipPlane, bool isectPlane, bool unionPlane,
                            const SkMatrix& localMatrix)
            : fLocalMatrix(localMatrix) {
        this->initClassID<CircleGeometryProcessor>();
        fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
                                             kHigh_GrSLPrecision);
        fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
        fInCircleEdge = &this->addVertexAttrib("inCircleEdge", kVec4f_GrVertexAttribType);
        if (clipPlane) {
            fInClipPlane = &this->addVertexAttrib("inClipPlane", kVec3f_GrVertexAttribType);
        } else {
            fInClipPlane = nullptr;
        }
        if (isectPlane) {
            fInIsectPlane = &this->addVertexAttrib("inIsectPlane", kVec3f_GrVertexAttribType);
        } else {
            fInIsectPlane = nullptr;
        }
        if (unionPlane) {
            fInUnionPlane = &this->addVertexAttrib("inUnionPlane", kVec3f_GrVertexAttribType);
        } else {
            fInUnionPlane = nullptr;
        }
        fStroke = stroke;
    }

    bool implementsDistanceVector() const override { return !fInClipPlane; };

    virtual ~CircleGeometryProcessor() {}

    const char* name() const override { return "CircleEdge"; }

    void getGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
        GLSLProcessor::GenKey(*this, caps, b);
    }

    GrGLSLPrimitiveProcessor* createGLSLInstance(const GrGLSLCaps&) const override {
        return new GLSLProcessor();
    }

private:
    class GLSLProcessor : public GrGLSLGeometryProcessor {
    public:
        GLSLProcessor() {}

        void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
            const CircleGeometryProcessor& cgp = args.fGP.cast<CircleGeometryProcessor>();
            GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
            GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
            GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
            GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;

            // emit attributes
            varyingHandler->emitAttributes(cgp);
            fragBuilder->codeAppend("vec4 circleEdge;");
            varyingHandler->addPassThroughAttribute(cgp.fInCircleEdge, "circleEdge");
            if (cgp.fInClipPlane) {
                fragBuilder->codeAppend("vec3 clipPlane;");
                varyingHandler->addPassThroughAttribute(cgp.fInClipPlane, "clipPlane");
            }
            if (cgp.fInIsectPlane) {
                SkASSERT(cgp.fInClipPlane);
                fragBuilder->codeAppend("vec3 isectPlane;");
                varyingHandler->addPassThroughAttribute(cgp.fInIsectPlane, "isectPlane");
            }
            if (cgp.fInUnionPlane) {
                SkASSERT(cgp.fInClipPlane);
                fragBuilder->codeAppend("vec3 unionPlane;");
                varyingHandler->addPassThroughAttribute(cgp.fInUnionPlane, "unionPlane");
            }

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

            // Setup position
            this->setupPosition(vertBuilder, gpArgs, cgp.fInPosition->fName);

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

            fragBuilder->codeAppend("float d = length(circleEdge.xy);");
            fragBuilder->codeAppend("float distanceToOuterEdge = circleEdge.z * (1.0 - d);");
            fragBuilder->codeAppend("float edgeAlpha = clamp(distanceToOuterEdge, 0.0, 1.0);");
            if (cgp.fStroke) {
                fragBuilder->codeAppend("float distanceToInnerEdge = circleEdge.z * (d - circleEdge.w);");
                fragBuilder->codeAppend("float innerAlpha = clamp(distanceToInnerEdge, 0.0, 1.0);");
                fragBuilder->codeAppend("edgeAlpha *= innerAlpha;");
            }

            if (args.fDistanceVectorName) {
                const char* innerEdgeDistance = cgp.fStroke ? "distanceToInnerEdge" : "0.0";
                fragBuilder->codeAppend ("if (d == 0.0) {"); // if on the center of the circle
                fragBuilder->codeAppendf("    %s = vec4(1.0, 0.0, distanceToOuterEdge, "
                                         "%s);", // no normalize
                                         args.fDistanceVectorName, innerEdgeDistance);
                fragBuilder->codeAppend ("} else {");
                fragBuilder->codeAppendf("    %s = vec4(normalize(circleEdge.xy), distanceToOuterEdge, %s);",
                                         args.fDistanceVectorName, innerEdgeDistance);
                fragBuilder->codeAppend ("}");
            }
            if (cgp.fInClipPlane) {
                fragBuilder->codeAppend("float clip = clamp(circleEdge.z * dot(circleEdge.xy, clipPlane.xy) + clipPlane.z, 0.0, 1.0);");
                if (cgp.fInIsectPlane) {
                    fragBuilder->codeAppend("clip *= clamp(circleEdge.z * dot(circleEdge.xy, isectPlane.xy) + isectPlane.z, 0.0, 1.0);");
                }
                if (cgp.fInUnionPlane) {
                    fragBuilder->codeAppend("clip += (1.0 - clip)*clamp(circleEdge.z * dot(circleEdge.xy, unionPlane.xy) + unionPlane.z, 0.0, 1.0);");
                }
                fragBuilder->codeAppend("edgeAlpha *= clip;");
            }
            fragBuilder->codeAppendf("%s = vec4(edgeAlpha);", args.fOutputCoverage);
        }

        static void GenKey(const GrGeometryProcessor& gp,
                           const GrGLSLCaps&,
                           GrProcessorKeyBuilder* b) {
            const CircleGeometryProcessor& cgp = gp.cast<CircleGeometryProcessor>();
            uint16_t key;
            key  = cgp.fStroke                       ? 0x01 : 0x0;
            key |= cgp.fLocalMatrix.hasPerspective() ? 0x02 : 0x0;
            key |= cgp.fInClipPlane                  ? 0x04 : 0x0;
            key |= cgp.fInIsectPlane                 ? 0x08 : 0x0;
            key |= cgp.fInUnionPlane                 ? 0x10 : 0x0;
            b->add32(key);
        }

        void setData(const GrGLSLProgramDataManager&, const GrPrimitiveProcessor&) override {}

        void setTransformData(const GrPrimitiveProcessor& primProc,
                              const GrGLSLProgramDataManager& pdman,
                              int index,
                              const SkTArray<const GrCoordTransform*, true>& transforms) override {
            this->setTransformDataHelper(primProc.cast<CircleGeometryProcessor>().fLocalMatrix,
                                         pdman, index, transforms);
        }

    private:
        typedef GrGLSLGeometryProcessor INHERITED;
    };

    SkMatrix         fLocalMatrix;
    const Attribute* fInPosition;
    const Attribute* fInColor;
    const Attribute* fInCircleEdge;
    const Attribute* fInClipPlane;
    const Attribute* fInIsectPlane;
    const Attribute* fInUnionPlane;
    bool             fStroke;

    GR_DECLARE_GEOMETRY_PROCESSOR_TEST;

    typedef GrGeometryProcessor INHERITED;
};

GR_DEFINE_GEOMETRY_PROCESSOR_TEST(CircleGeometryProcessor);

sk_sp<GrGeometryProcessor> CircleGeometryProcessor::TestCreate(GrProcessorTestData* d) {
    return sk_sp<GrGeometryProcessor>(
        new CircleGeometryProcessor(d->fRandom->nextBool(), d->fRandom->nextBool(),
                                    d->fRandom->nextBool(), d->fRandom->nextBool(),
                                    GrTest::TestMatrix(d->fRandom)));
}

///////////////////////////////////////////////////////////////////////////////

/**
 * The output of this effect is a modulation of the input color and coverage for an axis-aligned
 * ellipse, specified as a 2D offset from center, and the reciprocals of the outer and inner radii,
 * in both x and y directions.
 *
 * We are using an implicit function of x^2/a^2 + y^2/b^2 - 1 = 0.
 */

class EllipseGeometryProcessor : public GrGeometryProcessor {
public:
    EllipseGeometryProcessor(bool stroke, const SkMatrix& localMatrix)
        : fLocalMatrix(localMatrix) {
        this->initClassID<EllipseGeometryProcessor>();
        fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType);
        fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
        fInEllipseOffset = &this->addVertexAttrib("inEllipseOffset", kVec2f_GrVertexAttribType);
        fInEllipseRadii = &this->addVertexAttrib("inEllipseRadii", kVec4f_GrVertexAttribType);
        fStroke = stroke;
    }

    virtual ~EllipseGeometryProcessor() {}

    const char* name() const override { return "EllipseEdge"; }

    void getGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
        GLSLProcessor::GenKey(*this, caps, b);
    }

    GrGLSLPrimitiveProcessor* createGLSLInstance(const GrGLSLCaps&) const override {
        return new GLSLProcessor();
    }

private:
    class GLSLProcessor : public GrGLSLGeometryProcessor {
    public:
        GLSLProcessor() {}

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

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

            GrGLSLVertToFrag ellipseOffsets(kVec2f_GrSLType);
            varyingHandler->addVarying("EllipseOffsets", &ellipseOffsets);
            vertBuilder->codeAppendf("%s = %s;", ellipseOffsets.vsOut(),
                                     egp.fInEllipseOffset->fName);

            GrGLSLVertToFrag ellipseRadii(kVec4f_GrSLType);
            varyingHandler->addVarying("EllipseRadii", &ellipseRadii);
            vertBuilder->codeAppendf("%s = %s;", ellipseRadii.vsOut(),
                                     egp.fInEllipseRadii->fName);

            GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
            // setup pass through color
            varyingHandler->addPassThroughAttribute(egp.fInColor, args.fOutputColor);

            // Setup position
            this->setupPosition(vertBuilder, gpArgs, egp.fInPosition->fName);

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

            // for outer curve
            fragBuilder->codeAppendf("vec2 scaledOffset = %s*%s.xy;", ellipseOffsets.fsIn(),
                                     ellipseRadii.fsIn());
            fragBuilder->codeAppend("float test = dot(scaledOffset, scaledOffset) - 1.0;");
            fragBuilder->codeAppendf("vec2 grad = 2.0*scaledOffset*%s.xy;", ellipseRadii.fsIn());
            fragBuilder->codeAppend("float grad_dot = dot(grad, grad);");

            // avoid calling inversesqrt on zero.
            fragBuilder->codeAppend("grad_dot = max(grad_dot, 1.0e-4);");
            fragBuilder->codeAppend("float invlen = inversesqrt(grad_dot);");
            fragBuilder->codeAppend("float edgeAlpha = clamp(0.5-test*invlen, 0.0, 1.0);");

            // for inner curve
            if (egp.fStroke) {
                fragBuilder->codeAppendf("scaledOffset = %s*%s.zw;",
                                         ellipseOffsets.fsIn(), ellipseRadii.fsIn());
                fragBuilder->codeAppend("test = dot(scaledOffset, scaledOffset) - 1.0;");
                fragBuilder->codeAppendf("grad = 2.0*scaledOffset*%s.zw;",
                                         ellipseRadii.fsIn());
                fragBuilder->codeAppend("invlen = inversesqrt(dot(grad, grad));");
                fragBuilder->codeAppend("edgeAlpha *= clamp(0.5+test*invlen, 0.0, 1.0);");
            }

            fragBuilder->codeAppendf("%s = vec4(edgeAlpha);", args.fOutputCoverage);
        }

        static void GenKey(const GrGeometryProcessor& gp,
                           const GrGLSLCaps&,
                           GrProcessorKeyBuilder* b) {
            const EllipseGeometryProcessor& egp = gp.cast<EllipseGeometryProcessor>();
            uint16_t key = egp.fStroke ? 0x1 : 0x0;
            key |= egp.fLocalMatrix.hasPerspective() ? 0x2 : 0x0;
            b->add32(key);
        }

        void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& gp) override {
        }

        void setTransformData(const GrPrimitiveProcessor& primProc,
                              const GrGLSLProgramDataManager& pdman,
                              int index,
                              const SkTArray<const GrCoordTransform*, true>& transforms) override {
            this->setTransformDataHelper(primProc.cast<EllipseGeometryProcessor>().fLocalMatrix,
                                         pdman, index, transforms);
        }

    private:
        typedef GrGLSLGeometryProcessor INHERITED;
    };

    const Attribute* fInPosition;
    const Attribute* fInColor;
    const Attribute* fInEllipseOffset;
    const Attribute* fInEllipseRadii;
    SkMatrix fLocalMatrix;
    bool fStroke;

    GR_DECLARE_GEOMETRY_PROCESSOR_TEST;

    typedef GrGeometryProcessor INHERITED;
};

GR_DEFINE_GEOMETRY_PROCESSOR_TEST(EllipseGeometryProcessor);

sk_sp<GrGeometryProcessor> EllipseGeometryProcessor::TestCreate(GrProcessorTestData* d) {
    return sk_sp<GrGeometryProcessor>(
        new EllipseGeometryProcessor(d->fRandom->nextBool(), GrTest::TestMatrix(d->fRandom)));
}

///////////////////////////////////////////////////////////////////////////////

/**
 * The output of this effect is a modulation of the input color and coverage for an ellipse,
 * specified as a 2D offset from center for both the outer and inner paths (if stroked). The
 * implict equation used is for a unit circle (x^2 + y^2 - 1 = 0) and the edge corrected by
 * using differentials.
 *
 * The result is device-independent and can be used with any affine matrix.
 */

enum class DIEllipseStyle { kStroke = 0, kHairline, kFill };

class DIEllipseGeometryProcessor : public GrGeometryProcessor {
public:
    DIEllipseGeometryProcessor(const SkMatrix& viewMatrix, DIEllipseStyle style)
        : fViewMatrix(viewMatrix) {
        this->initClassID<DIEllipseGeometryProcessor>();
        fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
                                             kHigh_GrSLPrecision);
        fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
        fInEllipseOffsets0 = &this->addVertexAttrib("inEllipseOffsets0", kVec2f_GrVertexAttribType);
        fInEllipseOffsets1 = &this->addVertexAttrib("inEllipseOffsets1", kVec2f_GrVertexAttribType);
        fStyle = style;
    }


    virtual ~DIEllipseGeometryProcessor() {}

    const char* name() const override { return "DIEllipseEdge"; }

    void getGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
        GLSLProcessor::GenKey(*this, caps, b);
    }

    GrGLSLPrimitiveProcessor* createGLSLInstance(const GrGLSLCaps&) const override {
        return new GLSLProcessor();
    }

private:
    class GLSLProcessor : public GrGLSLGeometryProcessor {
    public:
        GLSLProcessor()
            : fViewMatrix(SkMatrix::InvalidMatrix()) {}

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

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

            GrGLSLVertToFrag offsets0(kVec2f_GrSLType);
            varyingHandler->addVarying("EllipseOffsets0", &offsets0);
            vertBuilder->codeAppendf("%s = %s;", offsets0.vsOut(),
                                     diegp.fInEllipseOffsets0->fName);

            GrGLSLVertToFrag offsets1(kVec2f_GrSLType);
            varyingHandler->addVarying("EllipseOffsets1", &offsets1);
            vertBuilder->codeAppendf("%s = %s;", offsets1.vsOut(),
                                     diegp.fInEllipseOffsets1->fName);

            GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
            varyingHandler->addPassThroughAttribute(diegp.fInColor, args.fOutputColor);

            // Setup position
            this->setupPosition(vertBuilder,
                                uniformHandler,
                                gpArgs,
                                diegp.fInPosition->fName,
                                diegp.fViewMatrix,
                                &fViewMatrixUniform);

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

            SkAssertResult(fragBuilder->enableFeature(
                    GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
            // for outer curve
            fragBuilder->codeAppendf("vec2 scaledOffset = %s.xy;", offsets0.fsIn());
            fragBuilder->codeAppend("float test = dot(scaledOffset, scaledOffset) - 1.0;");
            fragBuilder->codeAppendf("vec2 duvdx = dFdx(%s);", offsets0.fsIn());
            fragBuilder->codeAppendf("vec2 duvdy = dFdy(%s);", offsets0.fsIn());
            fragBuilder->codeAppendf("vec2 grad = vec2(2.0*%s.x*duvdx.x + 2.0*%s.y*duvdx.y,"
                                     "                 2.0*%s.x*duvdy.x + 2.0*%s.y*duvdy.y);",
                                     offsets0.fsIn(), offsets0.fsIn(), offsets0.fsIn(),
                                     offsets0.fsIn());

            fragBuilder->codeAppend("float grad_dot = dot(grad, grad);");
            // avoid calling inversesqrt on zero.
            fragBuilder->codeAppend("grad_dot = max(grad_dot, 1.0e-4);");
            fragBuilder->codeAppend("float invlen = inversesqrt(grad_dot);");
            if (DIEllipseStyle::kHairline == diegp.fStyle) {
                // can probably do this with one step
                fragBuilder->codeAppend("float edgeAlpha = clamp(1.0-test*invlen, 0.0, 1.0);");
                fragBuilder->codeAppend("edgeAlpha *= clamp(1.0+test*invlen, 0.0, 1.0);");
            } else {
                fragBuilder->codeAppend("float edgeAlpha = clamp(0.5-test*invlen, 0.0, 1.0);");
            }

            // for inner curve
            if (DIEllipseStyle::kStroke == diegp.fStyle) {
                fragBuilder->codeAppendf("scaledOffset = %s.xy;", offsets1.fsIn());
                fragBuilder->codeAppend("test = dot(scaledOffset, scaledOffset) - 1.0;");
                fragBuilder->codeAppendf("duvdx = dFdx(%s);", offsets1.fsIn());
                fragBuilder->codeAppendf("duvdy = dFdy(%s);", offsets1.fsIn());
                fragBuilder->codeAppendf("grad = vec2(2.0*%s.x*duvdx.x + 2.0*%s.y*duvdx.y,"
                                         "            2.0*%s.x*duvdy.x + 2.0*%s.y*duvdy.y);",
                                         offsets1.fsIn(), offsets1.fsIn(), offsets1.fsIn(),
                                         offsets1.fsIn());
                fragBuilder->codeAppend("invlen = inversesqrt(dot(grad, grad));");
                fragBuilder->codeAppend("edgeAlpha *= clamp(0.5+test*invlen, 0.0, 1.0);");
            }

            fragBuilder->codeAppendf("%s = vec4(edgeAlpha);", args.fOutputCoverage);
        }

        static void GenKey(const GrGeometryProcessor& gp,
                           const GrGLSLCaps&,
                           GrProcessorKeyBuilder* b) {
            const DIEllipseGeometryProcessor& diegp = gp.cast<DIEllipseGeometryProcessor>();
            uint16_t key = static_cast<uint16_t>(diegp.fStyle);
            key |= ComputePosKey(diegp.fViewMatrix) << 10;
            b->add32(key);
        }

        void setData(const GrGLSLProgramDataManager& pdman,
                     const GrPrimitiveProcessor& gp) override {
            const DIEllipseGeometryProcessor& diegp = gp.cast<DIEllipseGeometryProcessor>();

            if (!diegp.fViewMatrix.isIdentity() && !fViewMatrix.cheapEqualTo(diegp.fViewMatrix)) {
                fViewMatrix = diegp.fViewMatrix;
                float viewMatrix[3 * 3];
                GrGLSLGetMatrix<3>(viewMatrix, fViewMatrix);
                pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
            }
        }

    private:
        SkMatrix fViewMatrix;
        UniformHandle fViewMatrixUniform;

        typedef GrGLSLGeometryProcessor INHERITED;
    };

    const Attribute* fInPosition;
    const Attribute* fInColor;
    const Attribute* fInEllipseOffsets0;
    const Attribute* fInEllipseOffsets1;
    SkMatrix         fViewMatrix;
    DIEllipseStyle   fStyle;

    GR_DECLARE_GEOMETRY_PROCESSOR_TEST;

    typedef GrGeometryProcessor INHERITED;
};

GR_DEFINE_GEOMETRY_PROCESSOR_TEST(DIEllipseGeometryProcessor);

sk_sp<GrGeometryProcessor> DIEllipseGeometryProcessor::TestCreate(GrProcessorTestData* d) {
    return sk_sp<GrGeometryProcessor>(
        new DIEllipseGeometryProcessor(GrTest::TestMatrix(d->fRandom),
                                       (DIEllipseStyle)(d->fRandom->nextRangeU(0,2))));
}

///////////////////////////////////////////////////////////////////////////////

class CircleBatch : public GrVertexBatch {
public:
    DEFINE_BATCH_CLASS_ID

    /** Optional extra params to render a partial arc rather than a full circle. */
    struct ArcParams {
        SkScalar fStartAngleRadians;
        SkScalar fSweepAngleRadians;
        bool fUseCenter;
    };
    static GrDrawBatch* Create(GrColor color, const SkMatrix& viewMatrix, SkPoint center,
                               SkScalar radius, const GrStyle& style,
                               const ArcParams* arcParams = nullptr) {
        SkASSERT(circle_stays_circle(viewMatrix));
        const SkStrokeRec& stroke = style.strokeRec();
        if (style.hasPathEffect()) {
            return nullptr;
        }
        SkStrokeRec::Style recStyle = stroke.getStyle();
        if (arcParams) {
            // Arc support depends on the style.
            switch (recStyle) {
                case SkStrokeRec::kStrokeAndFill_Style:
                    // This produces a strange result that this batch doesn't implement.
                    return nullptr;
                case SkStrokeRec::kFill_Style:
                    // This supports all fills.
                    break;
                case SkStrokeRec::kStroke_Style: // fall through
                case SkStrokeRec::kHairline_Style:
                    // Strokes that don't use the center point are supported with butt cap.
                    if (arcParams->fUseCenter || stroke.getCap() != SkPaint::kButt_Cap) {
                        return nullptr;
                    }
                    break;
            }
        }

        viewMatrix.mapPoints(&center, 1);
        radius = viewMatrix.mapRadius(radius);
        SkScalar strokeWidth = viewMatrix.mapRadius(stroke.getWidth());

        bool isStrokeOnly = SkStrokeRec::kStroke_Style == recStyle ||
                            SkStrokeRec::kHairline_Style == recStyle;
        bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == recStyle;

        SkScalar innerRadius = 0.0f;
        SkScalar outerRadius = radius;
        SkScalar halfWidth = 0;
        if (hasStroke) {
            if (SkScalarNearlyZero(strokeWidth)) {
                halfWidth = SK_ScalarHalf;
            } else {
                halfWidth = SkScalarHalf(strokeWidth);
            }

            outerRadius += halfWidth;
            if (isStrokeOnly) {
                innerRadius = radius - halfWidth;
            }
        }

        // The radii are outset for two reasons. First, it allows the shader to simply perform
        // simpler computation because the computed alpha is zero, rather than 50%, at the radius.
        // Second, the outer radius is used to compute the verts of the bounding box that is
        // rendered and the outset ensures the box will cover all partially covered by the circle.
        outerRadius += SK_ScalarHalf;
        innerRadius -= SK_ScalarHalf;
        CircleBatch* batch = new CircleBatch();
        batch->fViewMatrixIfUsingLocalCoords = viewMatrix;

        // This makes every point fully inside the intersection plane.
        static constexpr SkScalar kUnusedIsectPlane[] = {0.f, 0.f, 1.f};
        // This makes every point fully outside the union plane.
        static constexpr SkScalar kUnusedUnionPlane[] = {0.f, 0.f, 0.f};
        SkRect devBounds = SkRect::MakeLTRB(center.fX - outerRadius, center.fY - outerRadius,
                                            center.fX + outerRadius, center.fY + outerRadius);

        if (arcParams) {
            // The shader operates in a space where the circle is translated to be centered at the
            // origin. Here we compute points on the unit circle at the starting and ending angles.
            SkPoint startPoint, stopPoint;
            startPoint.fY = SkScalarSinCos(arcParams->fStartAngleRadians, &startPoint.fX);
            SkScalar endAngle = arcParams->fStartAngleRadians + arcParams->fSweepAngleRadians;
            stopPoint.fY = SkScalarSinCos(endAngle, &stopPoint.fX);
            // Like a fill without useCenter, butt-cap stroke can be implemented by clipping against
            // radial lines. However, in both cases we have to be careful about the half-circle.
            // case. In that case the two radial lines are equal and so that edge gets clipped
            // twice. Since the shared edge goes through the center we fall back on the useCenter
            // case.
            bool useCenter = (arcParams->fUseCenter || isStrokeOnly) &&
                             !SkScalarNearlyEqual(SkScalarAbs(arcParams->fSweepAngleRadians),
                                                  SK_ScalarPI);
            if (useCenter) {
                SkVector norm0 = {startPoint.fY, -startPoint.fX};
                SkVector norm1 = {stopPoint.fY, -stopPoint.fX};
                if (arcParams->fSweepAngleRadians > 0) {
                    norm0.negate();
                } else {
                    norm1.negate();
                }
                batch->fClipPlane = true;
                if (SkScalarAbs(arcParams->fSweepAngleRadians) > SK_ScalarPI) {
                    batch->fGeoData.emplace_back(Geometry {
                            color,
                            innerRadius,
                            outerRadius,
                            {norm0.fX, norm0.fY, 0.5f},
                            {kUnusedIsectPlane[0], kUnusedIsectPlane[1], kUnusedIsectPlane[2]},
                            {norm1.fX, norm1.fY, 0.5f},
                            devBounds
                    });
                    batch->fClipPlaneIsect = false;
                    batch->fClipPlaneUnion = true;
                } else {
                    batch->fGeoData.emplace_back(Geometry {
                            color,
                            innerRadius,
                            outerRadius,
                            {norm0.fX, norm0.fY, 0.5f},
                            {norm1.fX, norm1.fY, 0.5f},
                            {kUnusedUnionPlane[0], kUnusedUnionPlane[1], kUnusedUnionPlane[2]},
                            devBounds
                    });
                    batch->fClipPlaneIsect = true;
                    batch->fClipPlaneUnion = false;
                }
            } else {
                // We clip to a secant of the original circle.
                startPoint.scale(radius);
                stopPoint.scale(radius);
                SkVector norm = {startPoint.fY - stopPoint.fY, stopPoint.fX - startPoint.fX};
                norm.normalize();
                if (arcParams->fSweepAngleRadians > 0) {
                    norm.negate();
                }
                SkScalar d = -norm.dot(startPoint) + 0.5f;

                batch->fGeoData.emplace_back(Geometry {
                        color,
                        innerRadius,
                        outerRadius,
                        {norm.fX, norm.fY, d},
                        {kUnusedIsectPlane[0], kUnusedIsectPlane[1], kUnusedIsectPlane[2]},
                        {kUnusedUnionPlane[0], kUnusedUnionPlane[1], kUnusedUnionPlane[2]},
                        devBounds
                });
                batch->fClipPlane = true;
                batch->fClipPlaneIsect = false;
                batch->fClipPlaneUnion = false;
            }
        } else {
            batch->fGeoData.emplace_back(Geometry {
                color,
                innerRadius,
                outerRadius,
                {kUnusedIsectPlane[0], kUnusedIsectPlane[1], kUnusedIsectPlane[2]},
                {kUnusedIsectPlane[0], kUnusedIsectPlane[1], kUnusedIsectPlane[2]},
                {kUnusedUnionPlane[0], kUnusedUnionPlane[1], kUnusedUnionPlane[2]},
                devBounds
            });
            batch->fClipPlane = false;
            batch->fClipPlaneIsect = false;
            batch->fClipPlaneUnion = false;
        }
        // Use the original radius and stroke radius for the bounds so that it does not include the
        // AA bloat.
        radius += halfWidth;
        batch->setBounds({center.fX - radius, center.fY - radius,
                          center.fX + radius, center.fY + radius},
                          HasAABloat::kYes, IsZeroArea::kNo);
        batch->fStroked = isStrokeOnly && innerRadius > 0;
        return batch;
    }

    const char* name() const override { return "CircleBatch"; }

    SkString dumpInfo() const override {
        SkString string;
        for (int i = 0; i < fGeoData.count(); ++i) {
            string.appendf("Color: 0x%08x Rect [L: %.2f, T: %.2f, R: %.2f, B: %.2f],"
                           "InnerRad: %.2f, OuterRad: %.2f\n",
                           fGeoData[i].fColor,
                           fGeoData[i].fDevBounds.fLeft, fGeoData[i].fDevBounds.fTop,
                           fGeoData[i].fDevBounds.fRight, fGeoData[i].fDevBounds.fBottom,
                           fGeoData[i].fInnerRadius,
                           fGeoData[i].fOuterRadius);
        }
        string.append(INHERITED::dumpInfo());
        return string;
    }

    void computePipelineOptimizations(GrInitInvariantOutput* color,
                                      GrInitInvariantOutput* coverage,
                                      GrBatchToXPOverrides* overrides) const override {
        // When this is called on a batch, there is only one geometry bundle
        color->setKnownFourComponents(fGeoData[0].fColor);
        coverage->setUnknownSingleComponent();
    }

private:
    CircleBatch() : INHERITED(ClassID()) {}
    void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
        // Handle any overrides that affect our GP.
        overrides.getOverrideColorIfSet(&fGeoData[0].fColor);
        if (!overrides.readsLocalCoords()) {
            fViewMatrixIfUsingLocalCoords.reset();
        }
    }

    void onPrepareDraws(Target* target) const override {
        SkMatrix localMatrix;
        if (!fViewMatrixIfUsingLocalCoords.invert(&localMatrix)) {
            return;
        }

        // Setup geometry processor
        SkAutoTUnref<GrGeometryProcessor> gp(new CircleGeometryProcessor(fStroked, fClipPlane,
                                                                         fClipPlaneIsect,
                                                                         fClipPlaneUnion,
                                                                         localMatrix));

        struct CircleVertex {
            SkPoint  fPos;
            GrColor  fColor;
            SkPoint  fOffset;
            SkScalar fOuterRadius;
            SkScalar fInnerRadius;
            // These planes may or may not be present in the vertex buffer.
            SkScalar fHalfPlanes[3][3];
        };

        int instanceCount = fGeoData.count();
        size_t vertexStride = gp->getVertexStride();
        SkASSERT(vertexStride == sizeof(CircleVertex) - (fClipPlane ? 0 : 3 * sizeof(SkScalar))
                                                      - (fClipPlaneIsect? 0 : 3 * sizeof(SkScalar))
                                                      - (fClipPlaneUnion? 0 : 3 * sizeof(SkScalar)));
        QuadHelper helper;
        char* vertices = reinterpret_cast<char*>(helper.init(target, vertexStride, instanceCount));
        if (!vertices) {
            return;
        }

        for (int i = 0; i < instanceCount; i++) {
            const Geometry& geom = fGeoData[i];

            GrColor color = geom.fColor;
            SkScalar innerRadius = geom.fInnerRadius;
            SkScalar outerRadius = geom.fOuterRadius;

            const SkRect& bounds = geom.fDevBounds;
            CircleVertex* v0 = reinterpret_cast<CircleVertex*>(vertices + (4 * i + 0)*vertexStride);
            CircleVertex* v1 = reinterpret_cast<CircleVertex*>(vertices + (4 * i + 1)*vertexStride);
            CircleVertex* v2 = reinterpret_cast<CircleVertex*>(vertices + (4 * i + 2)*vertexStride);
            CircleVertex* v3 = reinterpret_cast<CircleVertex*>(vertices + (4 * i + 3)*vertexStride);

            // The inner radius in the vertex data must be specified in normalized space.
            innerRadius = innerRadius / outerRadius;
            v0->fPos = SkPoint::Make(bounds.fLeft,  bounds.fTop);
            v0->fColor = color;
            v0->fOffset = SkPoint::Make(-1, -1);
            v0->fOuterRadius = outerRadius;
            v0->fInnerRadius = innerRadius;

            v1->fPos = SkPoint::Make(bounds.fLeft,  bounds.fBottom);
            v1->fColor = color;
            v1->fOffset = SkPoint::Make(-1, 1);
            v1->fOuterRadius = outerRadius;
            v1->fInnerRadius = innerRadius;

            v2->fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
            v2->fColor = color;
            v2->fOffset = SkPoint::Make(1, 1);
            v2->fOuterRadius = outerRadius;
            v2->fInnerRadius = innerRadius;

            v3->fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
            v3->fColor = color;
            v3->fOffset = SkPoint::Make(1, -1);
            v3->fOuterRadius = outerRadius;
            v3->fInnerRadius = innerRadius;

            if (fClipPlane) {
                memcpy(v0->fHalfPlanes[0], geom.fClipPlane, 3 * sizeof(SkScalar));
                memcpy(v1->fHalfPlanes[0], geom.fClipPlane, 3 * sizeof(SkScalar));
                memcpy(v2->fHalfPlanes[0], geom.fClipPlane, 3 * sizeof(SkScalar));
                memcpy(v3->fHalfPlanes[0], geom.fClipPlane, 3 * sizeof(SkScalar));
            }
            int unionIdx = 1;
            if (fClipPlaneIsect) {
                memcpy(v0->fHalfPlanes[1], geom.fIsectPlane, 3 * sizeof(SkScalar));
                memcpy(v1->fHalfPlanes[1], geom.fIsectPlane, 3 * sizeof(SkScalar));
                memcpy(v2->fHalfPlanes[1], geom.fIsectPlane, 3 * sizeof(SkScalar));
                memcpy(v3->fHalfPlanes[1], geom.fIsectPlane, 3 * sizeof(SkScalar));
                unionIdx = 2;
            }
            if (fClipPlaneUnion) {
                memcpy(v0->fHalfPlanes[unionIdx], geom.fUnionPlane, 3 * sizeof(SkScalar));
                memcpy(v1->fHalfPlanes[unionIdx], geom.fUnionPlane, 3 * sizeof(SkScalar));
                memcpy(v2->fHalfPlanes[unionIdx], geom.fUnionPlane, 3 * sizeof(SkScalar));
                memcpy(v3->fHalfPlanes[unionIdx], geom.fUnionPlane, 3 * sizeof(SkScalar));
            }
        }
        helper.recordDraw(target, gp);
    }

    bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
        CircleBatch* that = t->cast<CircleBatch>();
        if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
                                    that->bounds(), caps)) {
            return false;
        }

        if (this->fStroked != that->fStroked) {
            return false;
        }

        // Because we've set up the batches that don't use the planes with noop values
        // we can just accumulate used planes by later batches.
        fClipPlane |= that->fClipPlane;
        fClipPlaneIsect |= that->fClipPlaneIsect;
        fClipPlaneUnion |= that->fClipPlaneUnion;

        if (!fViewMatrixIfUsingLocalCoords.cheapEqualTo(that->fViewMatrixIfUsingLocalCoords)) {
            return false;
        }

        fGeoData.push_back_n(that->fGeoData.count(), that->fGeoData.begin());
        this->joinBounds(*that);
        return true;
    }

    struct Geometry {
        GrColor  fColor;
        SkScalar fInnerRadius;
        SkScalar fOuterRadius;
        SkScalar fClipPlane[3];
        SkScalar fIsectPlane[3];
        SkScalar fUnionPlane[3];
        SkRect   fDevBounds;
    };

    bool                         fStroked;
    bool                         fClipPlane;
    bool                         fClipPlaneIsect;
    bool                         fClipPlaneUnion;
    SkMatrix                     fViewMatrixIfUsingLocalCoords;
    SkSTArray<1, Geometry, true> fGeoData;

    typedef GrVertexBatch INHERITED;
};

///////////////////////////////////////////////////////////////////////////////

class EllipseBatch : public GrVertexBatch {
public:
    DEFINE_BATCH_CLASS_ID
    static GrDrawBatch* Create(GrColor color, const SkMatrix& viewMatrix, const SkRect& ellipse,
                               const SkStrokeRec& stroke) {
        SkASSERT(viewMatrix.rectStaysRect());

        // do any matrix crunching before we reset the draw state for device coords
        SkPoint center = SkPoint::Make(ellipse.centerX(), ellipse.centerY());
        viewMatrix.mapPoints(&center, 1);
        SkScalar ellipseXRadius = SkScalarHalf(ellipse.width());
        SkScalar ellipseYRadius = SkScalarHalf(ellipse.height());
        SkScalar xRadius = SkScalarAbs(viewMatrix[SkMatrix::kMScaleX]*ellipseXRadius +
                                       viewMatrix[SkMatrix::kMSkewY]*ellipseYRadius);
        SkScalar yRadius = SkScalarAbs(viewMatrix[SkMatrix::kMSkewX]*ellipseXRadius +
                                       viewMatrix[SkMatrix::kMScaleY]*ellipseYRadius);

        // do (potentially) anisotropic mapping of stroke
        SkVector scaledStroke;
        SkScalar strokeWidth = stroke.getWidth();
        scaledStroke.fX = SkScalarAbs(strokeWidth*(viewMatrix[SkMatrix::kMScaleX] +
                                                   viewMatrix[SkMatrix::kMSkewY]));
        scaledStroke.fY = SkScalarAbs(strokeWidth*(viewMatrix[SkMatrix::kMSkewX] +
                                                   viewMatrix[SkMatrix::kMScaleY]));

        SkStrokeRec::Style style = stroke.getStyle();
        bool isStrokeOnly = SkStrokeRec::kStroke_Style == style ||
                            SkStrokeRec::kHairline_Style == style;
        bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == style;

        SkScalar innerXRadius = 0;
        SkScalar innerYRadius = 0;
        if (hasStroke) {
            if (SkScalarNearlyZero(scaledStroke.length())) {
                scaledStroke.set(SK_ScalarHalf, SK_ScalarHalf);
            } else {
                scaledStroke.scale(SK_ScalarHalf);
            }

            // we only handle thick strokes for near-circular ellipses
            if (scaledStroke.length() > SK_ScalarHalf &&
                (SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
                return nullptr;
            }

            // we don't handle it if curvature of the stroke is less than curvature of the ellipse
            if (scaledStroke.fX*(yRadius*yRadius) < (scaledStroke.fY*scaledStroke.fY)*xRadius ||
                scaledStroke.fY*(xRadius*xRadius) < (scaledStroke.fX*scaledStroke.fX)*yRadius) {
                return nullptr;
            }

            // this is legit only if scale & translation (which should be the case at the moment)
            if (isStrokeOnly) {
                innerXRadius = xRadius - scaledStroke.fX;
                innerYRadius = yRadius - scaledStroke.fY;
            }

            xRadius += scaledStroke.fX;
            yRadius += scaledStroke.fY;
        }

        EllipseBatch* batch = new EllipseBatch();
        batch->fGeoData.emplace_back(Geometry {
            color,
            xRadius,
            yRadius,
            innerXRadius,
            innerYRadius,
            SkRect::MakeLTRB(center.fX - xRadius, center.fY - yRadius,
                             center.fX + xRadius, center.fY + yRadius)
        });

        batch->setBounds(batch->fGeoData.back().fDevBounds, HasAABloat::kYes, IsZeroArea::kNo);

        // Outset bounds to include half-pixel width antialiasing.
        batch->fGeoData[0].fDevBounds.outset(SK_ScalarHalf, SK_ScalarHalf);

        batch->fStroked = isStrokeOnly && innerXRadius > 0 && innerYRadius > 0;
        batch->fViewMatrixIfUsingLocalCoords = viewMatrix;
        return batch;
    }

    const char* name() const override { return "EllipseBatch"; }

    void computePipelineOptimizations(GrInitInvariantOutput* color,
                                      GrInitInvariantOutput* coverage,
                                      GrBatchToXPOverrides* overrides) const override {
        // When this is called on a batch, there is only one geometry bundle
        color->setKnownFourComponents(fGeoData[0].fColor);
        coverage->setUnknownSingleComponent();
    }

private:
    EllipseBatch() : INHERITED(ClassID()) {}

    void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
        // Handle any overrides that affect our GP.
        if (!overrides.readsCoverage()) {
            fGeoData[0].fColor = GrColor_ILLEGAL;
        }
        if (!overrides.readsLocalCoords()) {
            fViewMatrixIfUsingLocalCoords.reset();
        }
    }

    void onPrepareDraws(Target* target) const override {
        SkMatrix localMatrix;
        if (!fViewMatrixIfUsingLocalCoords.invert(&localMatrix)) {
            return;
        }

        // Setup geometry processor
        SkAutoTUnref<GrGeometryProcessor> gp(new EllipseGeometryProcessor(fStroked, localMatrix));

        int instanceCount = fGeoData.count();
        QuadHelper helper;
        size_t vertexStride = gp->getVertexStride();
        SkASSERT(vertexStride == sizeof(EllipseVertex));
        EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(
            helper.init(target, vertexStride, instanceCount));
        if (!verts) {
            return;
        }

        for (int i = 0; i < instanceCount; i++) {
            const Geometry& geom = fGeoData[i];

            GrColor color = geom.fColor;
            SkScalar xRadius = geom.fXRadius;
            SkScalar yRadius = geom.fYRadius;

            // Compute the reciprocals of the radii here to save time in the shader
            SkScalar xRadRecip = SkScalarInvert(xRadius);
            SkScalar yRadRecip = SkScalarInvert(yRadius);
            SkScalar xInnerRadRecip = SkScalarInvert(geom.fInnerXRadius);
            SkScalar yInnerRadRecip = SkScalarInvert(geom.fInnerYRadius);

            const SkRect& bounds = geom.fDevBounds;

            // fOffsets are expanded from xyRadii to include the half-pixel antialiasing width.
            SkScalar xMaxOffset = xRadius + SK_ScalarHalf;
            SkScalar yMaxOffset = yRadius + SK_ScalarHalf;

            // The inner radius in the vertex data must be specified in normalized space.
            verts[0].fPos = SkPoint::Make(bounds.fLeft,  bounds.fTop);
            verts[0].fColor = color;
            verts[0].fOffset = SkPoint::Make(-xMaxOffset, -yMaxOffset);
            verts[0].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
            verts[0].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);

            verts[1].fPos = SkPoint::Make(bounds.fLeft,  bounds.fBottom);
            verts[1].fColor = color;
            verts[1].fOffset = SkPoint::Make(-xMaxOffset, yMaxOffset);
            verts[1].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
            verts[1].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);

            verts[2].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
            verts[2].fColor = color;
            verts[2].fOffset = SkPoint::Make(xMaxOffset, yMaxOffset);
            verts[2].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
            verts[2].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);

            verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
            verts[3].fColor = color;
            verts[3].fOffset = SkPoint::Make(xMaxOffset, -yMaxOffset);
            verts[3].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
            verts[3].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);

            verts += kVerticesPerQuad;
        }
        helper.recordDraw(target, gp);
    }

    bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
        EllipseBatch* that = t->cast<EllipseBatch>();

        if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
                                    that->bounds(), caps)) {
            return false;
        }

        if (fStroked != that->fStroked) {
            return false;
        }

        if (!fViewMatrixIfUsingLocalCoords.cheapEqualTo(that->fViewMatrixIfUsingLocalCoords)) {
            return false;
        }

        fGeoData.push_back_n(that->fGeoData.count(), that->fGeoData.begin());
        this->joinBounds(*that);
        return true;
    }

    struct Geometry {
        GrColor fColor;
        SkScalar fXRadius;
        SkScalar fYRadius;
        SkScalar fInnerXRadius;
        SkScalar fInnerYRadius;
        SkRect fDevBounds;
    };

    bool                         fStroked;
    SkMatrix                     fViewMatrixIfUsingLocalCoords;
    SkSTArray<1, Geometry, true> fGeoData;

    typedef GrVertexBatch INHERITED;
};

/////////////////////////////////////////////////////////////////////////////////////////////////

class DIEllipseBatch : public GrVertexBatch {
public:
    DEFINE_BATCH_CLASS_ID

    static GrDrawBatch* Create(GrColor color,
                               const SkMatrix& viewMatrix,
                               const SkRect& ellipse,
                               const SkStrokeRec& stroke) {
        SkPoint center = SkPoint::Make(ellipse.centerX(), ellipse.centerY());
        SkScalar xRadius = SkScalarHalf(ellipse.width());
        SkScalar yRadius = SkScalarHalf(ellipse.height());

        SkStrokeRec::Style style = stroke.getStyle();
        DIEllipseStyle dieStyle = (SkStrokeRec::kStroke_Style == style) ?
                                  DIEllipseStyle::kStroke :
                                  (SkStrokeRec::kHairline_Style == style) ?
                                  DIEllipseStyle::kHairline : DIEllipseStyle::kFill;

        SkScalar innerXRadius = 0;
        SkScalar innerYRadius = 0;
        if (SkStrokeRec::kFill_Style != style && SkStrokeRec::kHairline_Style != style) {
            SkScalar strokeWidth = stroke.getWidth();

            if (SkScalarNearlyZero(strokeWidth)) {
                strokeWidth = SK_ScalarHalf;
            } else {
                strokeWidth *= SK_ScalarHalf;
            }

            // we only handle thick strokes for near-circular ellipses
            if (strokeWidth > SK_ScalarHalf &&
                (SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
                return nullptr;
            }

            // we don't handle it if curvature of the stroke is less than curvature of the ellipse
            if (strokeWidth*(yRadius*yRadius) < (strokeWidth*strokeWidth)*xRadius ||
                strokeWidth*(xRadius*xRadius) < (strokeWidth*strokeWidth)*yRadius) {
                return nullptr;
            }

            // set inner radius (if needed)
            if (SkStrokeRec::kStroke_Style == style) {
                innerXRadius = xRadius - strokeWidth;
                innerYRadius = yRadius - strokeWidth;
            }

            xRadius += strokeWidth;
            yRadius += strokeWidth;
        }
        if (DIEllipseStyle::kStroke == dieStyle) {
            dieStyle = (innerXRadius > 0 && innerYRadius > 0) ? DIEllipseStyle ::kStroke :
                       DIEllipseStyle ::kFill;
        }

        // This expands the outer rect so that after CTM we end up with a half-pixel border
        SkScalar a = viewMatrix[SkMatrix::kMScaleX];
        SkScalar b = viewMatrix[SkMatrix::kMSkewX];
        SkScalar c = viewMatrix[SkMatrix::kMSkewY];
        SkScalar d = viewMatrix[SkMatrix::kMScaleY];
        SkScalar geoDx = SK_ScalarHalf / SkScalarSqrt(a*a + c*c);
        SkScalar geoDy = SK_ScalarHalf / SkScalarSqrt(b*b + d*d);

        DIEllipseBatch* batch = new DIEllipseBatch();
        batch->fGeoData.emplace_back(Geometry {
            viewMatrix,
            color,
            xRadius,
            yRadius,
            innerXRadius,
            innerYRadius,
            geoDx,
            geoDy,
            dieStyle,
            SkRect::MakeLTRB(center.fX - xRadius - geoDx, center.fY - yRadius - geoDy,
                             center.fX + xRadius + geoDx, center.fY + yRadius + geoDy)
        });
        batch->setTransformedBounds(batch->fGeoData[0].fBounds, viewMatrix, HasAABloat::kYes,
                                    IsZeroArea::kNo);
        return batch;
    }

    const char* name() const override { return "DIEllipseBatch"; }

    void computePipelineOptimizations(GrInitInvariantOutput* color,
                                      GrInitInvariantOutput* coverage,
                                      GrBatchToXPOverrides* overrides) const override {
        // When this is called on a batch, there is only one geometry bundle
        color->setKnownFourComponents(fGeoData[0].fColor);
        coverage->setUnknownSingleComponent();
    }

private:

    DIEllipseBatch() : INHERITED(ClassID()) {}

    void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
        // Handle any overrides that affect our GP.
        overrides.getOverrideColorIfSet(&fGeoData[0].fColor);
        fUsesLocalCoords = overrides.readsLocalCoords();
    }

    void onPrepareDraws(Target* target) const override {
        // Setup geometry processor
        SkAutoTUnref<GrGeometryProcessor> gp(new DIEllipseGeometryProcessor(this->viewMatrix(),
                                                                            this->style()));

        int instanceCount = fGeoData.count();
        size_t vertexStride = gp->getVertexStride();
        SkASSERT(vertexStride == sizeof(DIEllipseVertex));
        QuadHelper helper;
        DIEllipseVertex* verts = reinterpret_cast<DIEllipseVertex*>(
            helper.init(target, vertexStride, instanceCount));
        if (!verts) {
            return;
        }

        for (int i = 0; i < instanceCount; i++) {
            const Geometry& geom = fGeoData[i];

            GrColor color = geom.fColor;
            SkScalar xRadius = geom.fXRadius;
            SkScalar yRadius = geom.fYRadius;

            const SkRect& bounds = geom.fBounds;

            // This adjusts the "radius" to include the half-pixel border
            SkScalar offsetDx = geom.fGeoDx / xRadius;
            SkScalar offsetDy = geom.fGeoDy / yRadius;

            SkScalar innerRatioX = xRadius / geom.fInnerXRadius;
            SkScalar innerRatioY = yRadius / geom.fInnerYRadius;

            verts[0].fPos = SkPoint::Make(bounds.fLeft, bounds.fTop);
            verts[0].fColor = color;
            verts[0].fOuterOffset = SkPoint::Make(-1.0f - offsetDx, -1.0f - offsetDy);
            verts[0].fInnerOffset = SkPoint::Make(-innerRatioX - offsetDx, -innerRatioY - offsetDy);

            verts[1].fPos = SkPoint::Make(bounds.fLeft,  bounds.fBottom);
            verts[1].fColor = color;
            verts[1].fOuterOffset = SkPoint::Make(-1.0f - offsetDx, 1.0f + offsetDy);
            verts[1].fInnerOffset = SkPoint::Make(-innerRatioX - offsetDx, innerRatioY + offsetDy);

            verts[2].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
            verts[2].fColor = color;
            verts[2].fOuterOffset = SkPoint::Make(1.0f + offsetDx, 1.0f + offsetDy);
            verts[2].fInnerOffset = SkPoint::Make(innerRatioX + offsetDx, innerRatioY + offsetDy);

            verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
            verts[3].fColor = color;
            verts[3].fOuterOffset = SkPoint::Make(1.0f + offsetDx, -1.0f - offsetDy);
            verts[3].fInnerOffset = SkPoint::Make(innerRatioX + offsetDx, -innerRatioY - offsetDy);

            verts += kVerticesPerQuad;
        }
        helper.recordDraw(target, gp);
    }

    bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
        DIEllipseBatch* that = t->cast<DIEllipseBatch>();
        if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
                                    that->bounds(), caps)) {
            return false;
        }

        if (this->style() != that->style()) {
            return false;
        }

        // TODO rewrite to allow positioning on CPU
        if (!this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
            return false;
        }

        fGeoData.push_back_n(that->fGeoData.count(), that->fGeoData.begin());
        this->joinBounds(*that);
        return true;
    }

    const SkMatrix& viewMatrix() const { return fGeoData[0].fViewMatrix; }
    DIEllipseStyle style() const { return fGeoData[0].fStyle; }

    struct Geometry {
        SkMatrix fViewMatrix;
        GrColor fColor;
        SkScalar fXRadius;
        SkScalar fYRadius;
        SkScalar fInnerXRadius;
        SkScalar fInnerYRadius;
        SkScalar fGeoDx;
        SkScalar fGeoDy;
        DIEllipseStyle fStyle;
        SkRect fBounds;
    };

    bool                         fUsesLocalCoords;
    SkSTArray<1, Geometry, true> fGeoData;

    typedef GrVertexBatch INHERITED;
};

///////////////////////////////////////////////////////////////////////////////

static const uint16_t gRRectIndices[] = {
    // corners
    0, 1, 5, 0, 5, 4,
    2, 3, 7, 2, 7, 6,
    8, 9, 13, 8, 13, 12,
    10, 11, 15, 10, 15, 14,

    // edges
    1, 2, 6, 1, 6, 5,
    4, 5, 9, 4, 9, 8,
    6, 7, 11, 6, 11, 10,
    9, 10, 14, 9, 14, 13,

    // center
    // we place this at the end so that we can ignore these indices when rendering stroke-only
    5, 6, 10, 5, 10, 9
};

static const int kIndicesPerStrokeRRect = SK_ARRAY_COUNT(gRRectIndices) - 6;
static const int kIndicesPerRRect = SK_ARRAY_COUNT(gRRectIndices);
static const int kVertsPerRRect = 16;
static const int kNumRRectsInIndexBuffer = 256;

GR_DECLARE_STATIC_UNIQUE_KEY(gStrokeRRectOnlyIndexBufferKey);
GR_DECLARE_STATIC_UNIQUE_KEY(gRRectOnlyIndexBufferKey);
static const GrBuffer* ref_rrect_index_buffer(bool strokeOnly,
                                              GrResourceProvider* resourceProvider) {
    GR_DEFINE_STATIC_UNIQUE_KEY(gStrokeRRectOnlyIndexBufferKey);
    GR_DEFINE_STATIC_UNIQUE_KEY(gRRectOnlyIndexBufferKey);
    if (strokeOnly) {
        return resourceProvider->findOrCreateInstancedIndexBuffer(
            gRRectIndices, kIndicesPerStrokeRRect, kNumRRectsInIndexBuffer, kVertsPerRRect,
            gStrokeRRectOnlyIndexBufferKey);
    } else {
        return resourceProvider->findOrCreateInstancedIndexBuffer(
            gRRectIndices, kIndicesPerRRect, kNumRRectsInIndexBuffer, kVertsPerRRect,
            gRRectOnlyIndexBufferKey);

    }
}

///////////////////////////////////////////////////////////////////////////////////////////////////

class RRectCircleRendererBatch : public GrVertexBatch {
public:
    DEFINE_BATCH_CLASS_ID

    // A devStrokeWidth <= 0 indicates a fill only. If devStrokeWidth > 0 then strokeOnly indicates
    // whether the rrect is only stroked or stroked and filled.
    RRectCircleRendererBatch(GrColor color, const SkMatrix& viewMatrix, const SkRect& devRect,
                             float devRadius, float devStrokeWidth, bool strokeOnly)
            : INHERITED(ClassID())
            , fViewMatrixIfUsingLocalCoords(viewMatrix) {
        SkRect bounds = devRect;
        SkASSERT(!(devStrokeWidth <= 0 && strokeOnly));
        SkScalar innerRadius = 0.0f;
        SkScalar outerRadius = devRadius;
        SkScalar halfWidth = 0;
        fStroked = false;
        if (devStrokeWidth > 0) {
            if (SkScalarNearlyZero(devStrokeWidth)) {
                halfWidth = SK_ScalarHalf;
            } else {
                halfWidth = SkScalarHalf(devStrokeWidth);
            }

            if (strokeOnly) {
                innerRadius = devRadius - halfWidth;
                fStroked = innerRadius >= 0;
            }
            outerRadius += halfWidth;
            bounds.outset(halfWidth, halfWidth);
        }

        // The radii are outset for two reasons. First, it allows the shader to simply perform
        // simpler computation because the computed alpha is zero, rather than 50%, at the radius.
        // Second, the outer radius is used to compute the verts of the bounding box that is
        // rendered and the outset ensures the box will cover all partially covered by the rrect
        // corners.
        outerRadius += SK_ScalarHalf;
        innerRadius -= SK_ScalarHalf;

        this->setBounds(bounds, HasAABloat::kYes, IsZeroArea::kNo);

        // Expand the rect for aa to generate correct vertices.
        bounds.outset(SK_ScalarHalf, SK_ScalarHalf);

        fGeoData.emplace_back(Geometry { color, innerRadius, outerRadius, bounds });
    }

    const char* name() const override { return "RRectCircleBatch"; }

    void computePipelineOptimizations(GrInitInvariantOutput* color,
                                      GrInitInvariantOutput* coverage,
                                      GrBatchToXPOverrides* overrides) const override {
        // When this is called on a batch, there is only one geometry bundle
        color->setKnownFourComponents(fGeoData[0].fColor);
        coverage->setUnknownSingleComponent();
    }

private:
    void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
        // Handle any overrides that affect our GP.
        overrides.getOverrideColorIfSet(&fGeoData[0].fColor);
        if (!overrides.readsLocalCoords()) {
            fViewMatrixIfUsingLocalCoords.reset();
        }
    }

    void onPrepareDraws(Target* target) const override {
        // Invert the view matrix as a local matrix (if any other processors require coords).
        SkMatrix localMatrix;
        if (!fViewMatrixIfUsingLocalCoords.invert(&localMatrix)) {
            return;
        }

        // Setup geometry processor
        SkAutoTUnref<GrGeometryProcessor> gp(new CircleGeometryProcessor(fStroked, false, false,
                                                                         false, localMatrix));

        struct CircleVertex {
            SkPoint  fPos;
            GrColor  fColor;
            SkPoint  fOffset;
            SkScalar fOuterRadius;
            SkScalar fInnerRadius;
            // No half plane, we don't use it here.
        };

        int instanceCount = fGeoData.count();
        size_t vertexStride = gp->getVertexStride();
        SkASSERT(vertexStride == sizeof(CircleVertex));

        // drop out the middle quad if we're stroked
        int indicesPerInstance = fStroked ? kIndicesPerStrokeRRect : kIndicesPerRRect;
        SkAutoTUnref<const GrBuffer> indexBuffer(
            ref_rrect_index_buffer(fStroked, target->resourceProvider()));

        InstancedHelper helper;
        CircleVertex* verts = reinterpret_cast<CircleVertex*>(helper.init(target,
            kTriangles_GrPrimitiveType, vertexStride, indexBuffer, kVertsPerRRect,
            indicesPerInstance, instanceCount));
        if (!verts || !indexBuffer) {
            SkDebugf("Could not allocate vertices\n");
            return;
        }

        for (int i = 0; i < instanceCount; i++) {
            const Geometry& args = fGeoData[i];

            GrColor color = args.fColor;
            SkScalar outerRadius = args.fOuterRadius;

            const SkRect& bounds = args.fDevBounds;

            SkScalar yCoords[4] = {
                bounds.fTop,
                bounds.fTop + outerRadius,
                bounds.fBottom - outerRadius,
                bounds.fBottom
            };

            SkScalar yOuterRadii[4] = {-1, 0, 0, 1 };
            // The inner radius in the vertex data must be specified in normalized space.
            SkScalar innerRadius = args.fInnerRadius / args.fOuterRadius;
            for (int i = 0; i < 4; ++i) {
                verts->fPos = SkPoint::Make(bounds.fLeft, yCoords[i]);
                verts->fColor = color;
                verts->fOffset = SkPoint::Make(-1, yOuterRadii[i]);
                verts->fOuterRadius = outerRadius;
                verts->fInnerRadius = innerRadius;
                verts++;

                verts->fPos = SkPoint::Make(bounds.fLeft + outerRadius, yCoords[i]);
                verts->fColor = color;
                verts->fOffset = SkPoint::Make(0, yOuterRadii[i]);
                verts->fOuterRadius = outerRadius;
                verts->fInnerRadius = innerRadius;
                verts++;

                verts->fPos = SkPoint::Make(bounds.fRight - outerRadius, yCoords[i]);
                verts->fColor = color;
                verts->fOffset = SkPoint::Make(0, yOuterRadii[i]);
                verts->fOuterRadius = outerRadius;
                verts->fInnerRadius = innerRadius;
                verts++;

                verts->fPos = SkPoint::Make(bounds.fRight, yCoords[i]);
                verts->fColor = color;
                verts->fOffset = SkPoint::Make(1, yOuterRadii[i]);
                verts->fOuterRadius = outerRadius;
                verts->fInnerRadius = innerRadius;
                verts++;
            }
        }

        helper.recordDraw(target, gp);
    }

    bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
        RRectCircleRendererBatch* that = t->cast<RRectCircleRendererBatch>();
        if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
                                    that->bounds(), caps)) {
            return false;
        }

        if (fStroked != that->fStroked) {
            return false;
        }

        if (!fViewMatrixIfUsingLocalCoords.cheapEqualTo(that->fViewMatrixIfUsingLocalCoords)) {
            return false;
        }

        fGeoData.push_back_n(that->fGeoData.count(), that->fGeoData.begin());
        this->joinBounds(*that);
        return true;
    }

    struct Geometry {
        GrColor  fColor;
        SkScalar fInnerRadius;
        SkScalar fOuterRadius;
        SkRect fDevBounds;
    };

    bool                         fStroked;
    SkMatrix                     fViewMatrixIfUsingLocalCoords;
    SkSTArray<1, Geometry, true> fGeoData;

    typedef GrVertexBatch INHERITED;
};

class RRectEllipseRendererBatch : public GrVertexBatch {
public:
    DEFINE_BATCH_CLASS_ID

    // If devStrokeWidths values are <= 0 indicates then fill only. Otherwise, strokeOnly indicates
    // whether the rrect is only stroked or stroked and filled.
    static GrDrawBatch* Create(GrColor color, const SkMatrix& viewMatrix, const SkRect& devRect,
                               float devXRadius, float devYRadius, SkVector devStrokeWidths,
                               bool strokeOnly) {
        SkASSERT(devXRadius > 0.5);
        SkASSERT(devYRadius > 0.5);
        SkASSERT((devStrokeWidths.fX > 0) == (devStrokeWidths.fY > 0));
        SkASSERT(!(strokeOnly && devStrokeWidths.fX <= 0));
        SkScalar innerXRadius = 0.0f;
        SkScalar innerYRadius = 0.0f;
        SkRect bounds = devRect;
        bool stroked = false;
        if (devStrokeWidths.fX > 0) {
            if (SkScalarNearlyZero(devStrokeWidths.length())) {
                devStrokeWidths.set(SK_ScalarHalf, SK_ScalarHalf);
            } else {
                devStrokeWidths.scale(SK_ScalarHalf);
            }

            // we only handle thick strokes for near-circular ellipses
            if (devStrokeWidths.length() > SK_ScalarHalf &&
                (SK_ScalarHalf*devXRadius > devYRadius || SK_ScalarHalf*devYRadius > devXRadius)) {
                return nullptr;
            }

            // we don't handle it if curvature of the stroke is less than curvature of the ellipse
            if (devStrokeWidths.fX*(devYRadius*devYRadius) <
                (devStrokeWidths.fY*devStrokeWidths.fY)*devXRadius) {
                return nullptr;
            }
            if (devStrokeWidths.fY*(devXRadius*devXRadius) <
                (devStrokeWidths.fX*devStrokeWidths.fX)*devYRadius) {
                return nullptr;
            }

            // this is legit only if scale & translation (which should be the case at the moment)
            if (strokeOnly) {
                innerXRadius = devXRadius - devStrokeWidths.fX;
                innerYRadius = devYRadius - devStrokeWidths.fY;
                stroked = (innerXRadius >= 0 && innerYRadius >= 0);
            }

            devXRadius += devStrokeWidths.fX;
            devYRadius += devStrokeWidths.fY;
            bounds.outset(devStrokeWidths.fX, devStrokeWidths.fY);
        }

        RRectEllipseRendererBatch* batch = new RRectEllipseRendererBatch();
        batch->fStroked = stroked;
        batch->fViewMatrixIfUsingLocalCoords = viewMatrix;
        batch->setBounds(bounds, HasAABloat::kYes, IsZeroArea::kNo);
        // Expand the rect for aa in order to generate the correct vertices.
        bounds.outset(SK_ScalarHalf, SK_ScalarHalf);
        batch->fGeoData.emplace_back(
            Geometry {color, devXRadius, devYRadius, innerXRadius, innerYRadius, bounds});
        return batch;
    }

    const char* name() const override { return "RRectEllipseRendererBatch"; }

    void computePipelineOptimizations(GrInitInvariantOutput* color,
                                      GrInitInvariantOutput* coverage,
                                      GrBatchToXPOverrides* overrides) const override {
        // When this is called on a batch, there is only one geometry bundle
        color->setKnownFourComponents(fGeoData[0].fColor);
        coverage->setUnknownSingleComponent();
    }

private:
    RRectEllipseRendererBatch() : INHERITED(ClassID()) {}

    void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
        // Handle overrides that affect our GP.
        overrides.getOverrideColorIfSet(&fGeoData[0].fColor);
        if (!overrides.readsLocalCoords()) {
            fViewMatrixIfUsingLocalCoords.reset();
        }
    }

    void onPrepareDraws(Target* target) const override {
        SkMatrix localMatrix;
        if (!fViewMatrixIfUsingLocalCoords.invert(&localMatrix)) {
            return;
        }

        // Setup geometry processor
        SkAutoTUnref<GrGeometryProcessor> gp(new EllipseGeometryProcessor(fStroked, localMatrix));

        int instanceCount = fGeoData.count();
        size_t vertexStride = gp->getVertexStride();
        SkASSERT(vertexStride == sizeof(EllipseVertex));

        // drop out the middle quad if we're stroked
        int indicesPerInstance = fStroked ? kIndicesPerStrokeRRect : kIndicesPerRRect;
        SkAutoTUnref<const GrBuffer> indexBuffer(
            ref_rrect_index_buffer(fStroked, target->resourceProvider()));

        InstancedHelper helper;
        EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(
            helper.init(target, kTriangles_GrPrimitiveType, vertexStride, indexBuffer,
            kVertsPerRRect, indicesPerInstance, instanceCount));
        if (!verts || !indexBuffer) {
            SkDebugf("Could not allocate vertices\n");
            return;
        }

        for (int i = 0; i < instanceCount; i++) {
            const Geometry& args = fGeoData[i];

            GrColor color = args.fColor;

            // Compute the reciprocals of the radii here to save time in the shader
            SkScalar xRadRecip = SkScalarInvert(args.fXRadius);
            SkScalar yRadRecip = SkScalarInvert(args.fYRadius);
            SkScalar xInnerRadRecip = SkScalarInvert(args.fInnerXRadius);
            SkScalar yInnerRadRecip = SkScalarInvert(args.fInnerYRadius);

            // Extend the radii out half a pixel to antialias.
            SkScalar xOuterRadius = args.fXRadius + SK_ScalarHalf;
            SkScalar yOuterRadius = args.fYRadius + SK_ScalarHalf;

            const SkRect& bounds = args.fDevBounds;

            SkScalar yCoords[4] = {
                bounds.fTop,
                bounds.fTop + yOuterRadius,
                bounds.fBottom - yOuterRadius,
                bounds.fBottom
            };
            SkScalar yOuterOffsets[4] = {
                yOuterRadius,
                SK_ScalarNearlyZero, // we're using inversesqrt() in shader, so can't be exactly 0
                SK_ScalarNearlyZero,
                yOuterRadius
            };

            for (int i = 0; i < 4; ++i) {
                verts->fPos = SkPoint::Make(bounds.fLeft, yCoords[i]);
                verts->fColor = color;
                verts->fOffset = SkPoint::Make(xOuterRadius, yOuterOffsets[i]);
                verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
                verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
                verts++;

                verts->fPos = SkPoint::Make(bounds.fLeft + xOuterRadius, yCoords[i]);
                verts->fColor = color;
                verts->fOffset = SkPoint::Make(SK_ScalarNearlyZero, yOuterOffsets[i]);
                verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
                verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
                verts++;

                verts->fPos = SkPoint::Make(bounds.fRight - xOuterRadius, yCoords[i]);
                verts->fColor = color;
                verts->fOffset = SkPoint::Make(SK_ScalarNearlyZero, yOuterOffsets[i]);
                verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
                verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
                verts++;

                verts->fPos = SkPoint::Make(bounds.fRight, yCoords[i]);
                verts->fColor = color;
                verts->fOffset = SkPoint::Make(xOuterRadius, yOuterOffsets[i]);
                verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
                verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
                verts++;
            }
        }
        helper.recordDraw(target, gp);
    }

    bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
        RRectEllipseRendererBatch* that = t->cast<RRectEllipseRendererBatch>();

        if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
                                    that->bounds(), caps)) {
            return false;
        }

        if (fStroked != that->fStroked) {
            return false;
        }

        if (!fViewMatrixIfUsingLocalCoords.cheapEqualTo(that->fViewMatrixIfUsingLocalCoords)) {
            return false;
        }

        fGeoData.push_back_n(that->fGeoData.count(), that->fGeoData.begin());
        this->joinBounds(*that);
        return true;
    }

    struct Geometry {
        GrColor fColor;
        SkScalar fXRadius;
        SkScalar fYRadius;
        SkScalar fInnerXRadius;
        SkScalar fInnerYRadius;
        SkRect fDevBounds;
    };

    bool                            fStroked;
    SkMatrix                        fViewMatrixIfUsingLocalCoords;
    SkSTArray<1, Geometry, true>    fGeoData;

    typedef GrVertexBatch INHERITED;
};

static GrDrawBatch* create_rrect_batch(GrColor color,
                                       const SkMatrix& viewMatrix,
                                       const SkRRect& rrect,
                                       const SkStrokeRec& stroke) {
    SkASSERT(viewMatrix.rectStaysRect());
    SkASSERT(rrect.isSimple());
    SkASSERT(!rrect.isOval());

    // RRect batchs only handle simple, but not too simple, rrects
    // do any matrix crunching before we reset the draw state for device coords
    const SkRect& rrectBounds = rrect.getBounds();
    SkRect bounds;
    viewMatrix.mapRect(&bounds, rrectBounds);

    SkVector radii = rrect.getSimpleRadii();
    SkScalar xRadius = SkScalarAbs(viewMatrix[SkMatrix::kMScaleX]*radii.fX +
                                   viewMatrix[SkMatrix::kMSkewY]*radii.fY);
    SkScalar yRadius = SkScalarAbs(viewMatrix[SkMatrix::kMSkewX]*radii.fX +
                                   viewMatrix[SkMatrix::kMScaleY]*radii.fY);

    SkStrokeRec::Style style = stroke.getStyle();

    // Do (potentially) anisotropic mapping of stroke. Use -1s to indicate fill-only draws.
    SkVector scaledStroke = {-1, -1};
    SkScalar strokeWidth = stroke.getWidth();

    bool isStrokeOnly = SkStrokeRec::kStroke_Style == style ||
                        SkStrokeRec::kHairline_Style == style;
    bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == style;

    if (hasStroke) {
        if (SkStrokeRec::kHairline_Style == style) {
            scaledStroke.set(1, 1);
        } else {
            scaledStroke.fX = SkScalarAbs(strokeWidth*(viewMatrix[SkMatrix::kMScaleX] +
                                                       viewMatrix[SkMatrix::kMSkewY]));
            scaledStroke.fY = SkScalarAbs(strokeWidth*(viewMatrix[SkMatrix::kMSkewX] +
                                                       viewMatrix[SkMatrix::kMScaleY]));
        }

        // if half of strokewidth is greater than radius, we don't handle that right now
        if (SK_ScalarHalf*scaledStroke.fX > xRadius || SK_ScalarHalf*scaledStroke.fY > yRadius) {
            return nullptr;
        }
    }

    // The way the effect interpolates the offset-to-ellipse/circle-center attribute only works on
    // the interior of the rrect if the radii are >= 0.5. Otherwise, the inner rect of the nine-
    // patch will have fractional coverage. This only matters when the interior is actually filled.
    // We could consider falling back to rect rendering here, since a tiny radius is
    // indistinguishable from a square corner.
    if (!isStrokeOnly && (SK_ScalarHalf > xRadius || SK_ScalarHalf > yRadius)) {
        return nullptr;
    }

    // if the corners are circles, use the circle renderer
    if ((!hasStroke || scaledStroke.fX == scaledStroke.fY) && xRadius == yRadius) {
        return new RRectCircleRendererBatch(color, viewMatrix, bounds, xRadius, scaledStroke.fX,
                                            isStrokeOnly);
    // otherwise we use the ellipse renderer
    } else {
        return RRectEllipseRendererBatch::Create(color, viewMatrix, bounds, xRadius, yRadius,
                                                 scaledStroke, isStrokeOnly);

    }
}

GrDrawBatch* GrOvalRenderer::CreateRRectBatch(GrColor color,
                                              const SkMatrix& viewMatrix,
                                              const SkRRect& rrect,
                                              const SkStrokeRec& stroke,
                                              const GrShaderCaps* shaderCaps) {
    if (rrect.isOval()) {
        return CreateOvalBatch(color, viewMatrix, rrect.getBounds(), stroke, shaderCaps);
    }

    if (!viewMatrix.rectStaysRect() || !rrect.isSimple()) {
        return nullptr;
    }

    return create_rrect_batch(color, viewMatrix, rrect, stroke);
}

///////////////////////////////////////////////////////////////////////////////

GrDrawBatch* GrOvalRenderer::CreateOvalBatch(GrColor color,
                                             const SkMatrix& viewMatrix,
                                             const SkRect& oval,
                                             const SkStrokeRec& stroke,
                                             const GrShaderCaps* shaderCaps) {
    // we can draw circles
    SkScalar width = oval.width();
    if (SkScalarNearlyEqual(width, oval.height()) && circle_stays_circle(viewMatrix)) {
        SkPoint center = {oval.centerX(), oval.centerY()};
        return CircleBatch::Create(color, viewMatrix, center, width / 2.f,
                                   GrStyle(stroke, nullptr));
    }

    // if we have shader derivative support, render as device-independent
    if (shaderCaps->shaderDerivativeSupport()) {
        return DIEllipseBatch::Create(color, viewMatrix, oval, stroke);
    }

    // otherwise axis-aligned ellipses only
    if (viewMatrix.rectStaysRect()) {
        return EllipseBatch::Create(color, viewMatrix, oval, stroke);
    }

    return nullptr;
}

///////////////////////////////////////////////////////////////////////////////

GrDrawBatch* GrOvalRenderer::CreateArcBatch(GrColor color,
                                            const SkMatrix& viewMatrix,
                                            const SkRect& oval,
                                            SkScalar startAngle, SkScalar sweepAngle,
                                            bool useCenter,
                                            const GrStyle& style,
                                            const GrShaderCaps* shaderCaps) {
    SkScalar width = oval.width();
    if (!SkScalarNearlyEqual(width, oval.height()) || !circle_stays_circle(viewMatrix)) {
        return nullptr;
    }
    SkPoint center = {oval.centerX(), oval.centerY()};
    CircleBatch::ArcParams arcParams = {
        SkDegreesToRadians(startAngle),
        SkDegreesToRadians(sweepAngle),
        useCenter
    };
    return CircleBatch::Create(color, viewMatrix, center, width/2.f, style, &arcParams);
}

///////////////////////////////////////////////////////////////////////////////

#ifdef GR_TEST_UTILS

DRAW_BATCH_TEST_DEFINE(CircleBatch) {
    do {
        SkScalar rotate = random->nextSScalar1() * 360.f;
        SkScalar translateX = random->nextSScalar1() * 1000.f;
        SkScalar translateY = random->nextSScalar1() * 1000.f;
        SkScalar scale = random->nextSScalar1() * 100.f;
        SkMatrix viewMatrix;
        viewMatrix.setRotate(rotate);
        viewMatrix.postTranslate(translateX, translateY);
        viewMatrix.postScale(scale, scale);
        GrColor color = GrRandomColor(random);
        SkRect circle = GrTest::TestSquare(random);
        SkPoint center = {circle.centerX(), circle.centerY()};
        SkScalar radius = circle.width() / 2.f;
        SkStrokeRec stroke = GrTest::TestStrokeRec(random);
        CircleBatch::ArcParams arcParamsTmp;
        const CircleBatch::ArcParams* arcParams = nullptr;
        if (random->nextBool()) {
            arcParamsTmp.fStartAngleRadians = random->nextSScalar1() * SK_ScalarPI * 2;
            arcParamsTmp.fSweepAngleRadians = random->nextSScalar1() * SK_ScalarPI * 2 - .01f;
            arcParamsTmp.fUseCenter = random->nextBool();
            arcParams = &arcParamsTmp;
        }
        GrDrawBatch* batch = CircleBatch::Create(color, viewMatrix, center, radius,
                                                 GrStyle(stroke, nullptr), arcParams);
        if (batch) {
            return batch;
        }
    } while (true);
}

DRAW_BATCH_TEST_DEFINE(EllipseBatch) {
    SkMatrix viewMatrix = GrTest::TestMatrixRectStaysRect(random);
    GrColor color = GrRandomColor(random);
    SkRect ellipse = GrTest::TestSquare(random);
    return EllipseBatch::Create(color, viewMatrix, ellipse, GrTest::TestStrokeRec(random));
}

DRAW_BATCH_TEST_DEFINE(DIEllipseBatch) {
    SkMatrix viewMatrix = GrTest::TestMatrix(random);
    GrColor color = GrRandomColor(random);
    SkRect ellipse = GrTest::TestSquare(random);
    return DIEllipseBatch::Create(color, viewMatrix, ellipse, GrTest::TestStrokeRec(random));
}

DRAW_BATCH_TEST_DEFINE(RRectBatch) {
    SkMatrix viewMatrix = GrTest::TestMatrixRectStaysRect(random);
    GrColor color = GrRandomColor(random);
    const SkRRect& rrect = GrTest::TestRRectSimple(random);
    return create_rrect_batch(color, viewMatrix, rrect, GrTest::TestStrokeRec(random));
}

#endif