src/gpu/effects/GrOvalEffect.cpp - platform/external/skqp - Gitiles

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "GrOvalEffect.h"

 #include "GrFragmentProcessor.h"
 #include "GrInvariantOutput.h"
 #include "SkRect.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProgramBuilder.h"
 #include "glsl/GrGLSLProgramDataManager.h"

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

 class CircleEffect : public GrFragmentProcessor {
 public:
     static GrFragmentProcessor* Create(GrPrimitiveEdgeType, const SkPoint& center, SkScalar radius);

     virtual ~CircleEffect() {};

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

     const SkPoint& getCenter() const { return fCenter; }
     SkScalar getRadius() const { return fRadius; }

     GrPrimitiveEdgeType getEdgeType() const { return fEdgeType; }

 private:
     CircleEffect(GrPrimitiveEdgeType, const SkPoint& center, SkScalar radius);

     GrGLSLFragmentProcessor* onCreateGLInstance() const override;

     void onGetGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;

     bool onIsEqual(const GrFragmentProcessor&) const override;

     void onComputeInvariantOutput(GrInvariantOutput* inout) const override;

     SkPoint             fCenter;
     SkScalar            fRadius;
     GrPrimitiveEdgeType    fEdgeType;

     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

     typedef GrFragmentProcessor INHERITED;
 };

 GrFragmentProcessor* CircleEffect::Create(GrPrimitiveEdgeType edgeType, const SkPoint& center,
                                           SkScalar radius) {
     SkASSERT(radius >= 0);
     return new CircleEffect(edgeType, center, radius);
 }

 void CircleEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
     inout->mulByUnknownSingleComponent();
 }

 CircleEffect::CircleEffect(GrPrimitiveEdgeType edgeType, const SkPoint& c, SkScalar r)
     : fCenter(c)
     , fRadius(r)
     , fEdgeType(edgeType) {
     this->initClassID<CircleEffect>();
     this->setWillReadFragmentPosition();
 }

 bool CircleEffect::onIsEqual(const GrFragmentProcessor& other) const {
     const CircleEffect& ce = other.cast<CircleEffect>();
     return fEdgeType == ce.fEdgeType && fCenter == ce.fCenter && fRadius == ce.fRadius;
 }

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

 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(CircleEffect);

 const GrFragmentProcessor* CircleEffect::TestCreate(GrProcessorTestData* d) {
     SkPoint center;
     center.fX = d->fRandom->nextRangeScalar(0.f, 1000.f);
     center.fY = d->fRandom->nextRangeScalar(0.f, 1000.f);
     SkScalar radius = d->fRandom->nextRangeF(0.f, 1000.f);
     GrPrimitiveEdgeType et;
     do {
         et = (GrPrimitiveEdgeType)d->fRandom->nextULessThan(kGrProcessorEdgeTypeCnt);
     } while (kHairlineAA_GrProcessorEdgeType == et);
     return CircleEffect::Create(et, center, radius);
 }

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

 class GLCircleEffect : public GrGLSLFragmentProcessor {
 public:
     GLCircleEffect(const GrProcessor&);

     virtual void emitCode(EmitArgs&) override;

     static inline void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*);

 protected:
     void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;

 private:
     GrGLSLProgramDataManager::UniformHandle fCircleUniform;
     SkPoint                                 fPrevCenter;
     SkScalar                                fPrevRadius;

     typedef GrGLSLFragmentProcessor INHERITED;
 };

 GLCircleEffect::GLCircleEffect(const GrProcessor&) {
     fPrevRadius = -1.f;
 }

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

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

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

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

 void GLCircleEffect::GenKey(const GrProcessor& processor, const GrGLSLCaps&,
                             GrProcessorKeyBuilder* b) {
     const CircleEffect& ce = processor.cast<CircleEffect>();
     b->add32(ce.getEdgeType());
 }

 void GLCircleEffect::onSetData(const GrGLSLProgramDataManager& pdman,
                                const GrProcessor& processor) {
     const CircleEffect& ce = processor.cast<CircleEffect>();
     if (ce.getRadius() != fPrevRadius || ce.getCenter() != fPrevCenter) {
         SkScalar radius = ce.getRadius();
         if (GrProcessorEdgeTypeIsInverseFill(ce.getEdgeType())) {
             radius -= 0.5f;
         } else {
             radius += 0.5f;
         }
         pdman.set4f(fCircleUniform, ce.getCenter().fX, ce.getCenter().fY, radius,
                     SkScalarInvert(radius));
         fPrevCenter = ce.getCenter();
         fPrevRadius = ce.getRadius();
     }
 }

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

 void CircleEffect::onGetGLProcessorKey(const GrGLSLCaps& caps,
                                      GrProcessorKeyBuilder* b) const {
     GLCircleEffect::GenKey(*this, caps, b);
 }

 GrGLSLFragmentProcessor* CircleEffect::onCreateGLInstance() const  {
     return new GLCircleEffect(*this);
 }

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

 class EllipseEffect : public GrFragmentProcessor {
 public:
     static GrFragmentProcessor* Create(GrPrimitiveEdgeType, const SkPoint& center, SkScalar rx,
                                        SkScalar ry);

     virtual ~EllipseEffect() {};

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

     const SkPoint& getCenter() const { return fCenter; }
     SkVector getRadii() const { return fRadii; }

     GrPrimitiveEdgeType getEdgeType() const { return fEdgeType; }

 private:
     EllipseEffect(GrPrimitiveEdgeType, const SkPoint& center, SkScalar rx, SkScalar ry);

     GrGLSLFragmentProcessor* onCreateGLInstance() const override;

     void onGetGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;

     bool onIsEqual(const GrFragmentProcessor&) const override;

     void onComputeInvariantOutput(GrInvariantOutput* inout) const override;

     SkPoint             fCenter;
     SkVector            fRadii;
     GrPrimitiveEdgeType    fEdgeType;

     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

     typedef GrFragmentProcessor INHERITED;
 };

 GrFragmentProcessor* EllipseEffect::Create(GrPrimitiveEdgeType edgeType,
                                            const SkPoint& center,
                                            SkScalar rx,
                                            SkScalar ry) {
     SkASSERT(rx >= 0 && ry >= 0);
     return new EllipseEffect(edgeType, center, rx, ry);
 }

 void EllipseEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
     inout->mulByUnknownSingleComponent();
 }

 EllipseEffect::EllipseEffect(GrPrimitiveEdgeType edgeType, const SkPoint& c, SkScalar rx, SkScalar ry)
     : fCenter(c)
     , fRadii(SkVector::Make(rx, ry))
     , fEdgeType(edgeType) {
     this->initClassID<EllipseEffect>();
     this->setWillReadFragmentPosition();
 }

 bool EllipseEffect::onIsEqual(const GrFragmentProcessor& other) const {
     const EllipseEffect& ee = other.cast<EllipseEffect>();
     return fEdgeType == ee.fEdgeType && fCenter == ee.fCenter && fRadii == ee.fRadii;
 }

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

 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(EllipseEffect);

 const GrFragmentProcessor* EllipseEffect::TestCreate(GrProcessorTestData* d) {
     SkPoint center;
     center.fX = d->fRandom->nextRangeScalar(0.f, 1000.f);
     center.fY = d->fRandom->nextRangeScalar(0.f, 1000.f);
     SkScalar rx = d->fRandom->nextRangeF(0.f, 1000.f);
     SkScalar ry = d->fRandom->nextRangeF(0.f, 1000.f);
     GrPrimitiveEdgeType et;
     do {
         et = (GrPrimitiveEdgeType)d->fRandom->nextULessThan(kGrProcessorEdgeTypeCnt);
     } while (kHairlineAA_GrProcessorEdgeType == et);
     return EllipseEffect::Create(et, center, rx, ry);
 }

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

 class GLEllipseEffect : public GrGLSLFragmentProcessor {
 public:
     GLEllipseEffect(const GrProcessor&);

     virtual void emitCode(EmitArgs&) override;

     static inline void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*);

 protected:
     void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;

 private:
     GrGLSLProgramDataManager::UniformHandle fEllipseUniform;
     SkPoint                                 fPrevCenter;
     SkVector                                fPrevRadii;

     typedef GrGLSLFragmentProcessor INHERITED;
 };

 GLEllipseEffect::GLEllipseEffect(const GrProcessor& effect) {
     fPrevRadii.fX = -1.f;
 }

 void GLEllipseEffect::emitCode(EmitArgs& args) {
     const EllipseEffect& ee = args.fFp.cast<EllipseEffect>();
     const char *ellipseName;
     // The ellipse uniform is (center.x, center.y, 1 / rx^2, 1 / ry^2)
     // The last two terms can underflow on mediump, so we use highp.
     fEllipseUniform = args.fBuilder->addUniform(GrGLSLProgramBuilder::kFragment_Visibility,
                                          kVec4f_GrSLType, kHigh_GrSLPrecision,
                                          "ellipse",
                                          &ellipseName);

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

     // d is the offset to the ellipse center
     fsBuilder->codeAppendf("\t\tvec2 d = %s.xy - %s.xy;\n", fragmentPos, ellipseName);
     fsBuilder->codeAppendf("\t\tvec2 Z = d * %s.zw;\n", ellipseName);
     // implicit is the evaluation of (x/rx)^2 + (y/ry)^2 - 1.
     fsBuilder->codeAppend("\t\tfloat implicit = dot(Z, d) - 1.0;\n");
     // grad_dot is the squared length of the gradient of the implicit.
     fsBuilder->codeAppendf("\t\tfloat grad_dot = 4.0 * dot(Z, Z);\n");
     // avoid calling inversesqrt on zero.
     fsBuilder->codeAppend("\t\tgrad_dot = max(grad_dot, 1.0e-4);\n");
     fsBuilder->codeAppendf("\t\tfloat approx_dist = implicit * inversesqrt(grad_dot);\n");

     switch (ee.getEdgeType()) {
         case kFillAA_GrProcessorEdgeType:
             fsBuilder->codeAppend("\t\tfloat alpha = clamp(0.5 - approx_dist, 0.0, 1.0);\n");
             break;
         case kInverseFillAA_GrProcessorEdgeType:
             fsBuilder->codeAppend("\t\tfloat alpha = clamp(0.5 + approx_dist, 0.0, 1.0);\n");
             break;
         case kFillBW_GrProcessorEdgeType:
             fsBuilder->codeAppend("\t\tfloat alpha = approx_dist > 0.0 ? 0.0 : 1.0;\n");
             break;
         case kInverseFillBW_GrProcessorEdgeType:
             fsBuilder->codeAppend("\t\tfloat alpha = approx_dist > 0.0 ? 1.0 : 0.0;\n");
             break;
         case kHairlineAA_GrProcessorEdgeType:
             SkFAIL("Hairline not expected here.");
     }

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

 void GLEllipseEffect::GenKey(const GrProcessor& effect, const GrGLSLCaps&,
                              GrProcessorKeyBuilder* b) {
     const EllipseEffect& ee = effect.cast<EllipseEffect>();
     b->add32(ee.getEdgeType());
 }

 void GLEllipseEffect::onSetData(const GrGLSLProgramDataManager& pdman,
                                 const GrProcessor& effect) {
     const EllipseEffect& ee = effect.cast<EllipseEffect>();
     if (ee.getRadii() != fPrevRadii || ee.getCenter() != fPrevCenter) {
         SkScalar invRXSqd = 1.f / (ee.getRadii().fX * ee.getRadii().fX);
         SkScalar invRYSqd = 1.f / (ee.getRadii().fY * ee.getRadii().fY);
         pdman.set4f(fEllipseUniform, ee.getCenter().fX, ee.getCenter().fY, invRXSqd, invRYSqd);
         fPrevCenter = ee.getCenter();
         fPrevRadii = ee.getRadii();
     }
 }

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

 void EllipseEffect::onGetGLProcessorKey(const GrGLSLCaps& caps,
                                      GrProcessorKeyBuilder* b) const {
     GLEllipseEffect::GenKey(*this, caps, b);
 }

 GrGLSLFragmentProcessor* EllipseEffect::onCreateGLInstance() const  {
     return new GLEllipseEffect(*this);
 }

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

 GrFragmentProcessor* GrOvalEffect::Create(GrPrimitiveEdgeType edgeType, const SkRect& oval) {
     if (kHairlineAA_GrProcessorEdgeType == edgeType) {
         return nullptr;
     }
     SkScalar w = oval.width();
     SkScalar h = oval.height();
     if (SkScalarNearlyEqual(w, h)) {
         w /= 2;
         return CircleEffect::Create(edgeType, SkPoint::Make(oval.fLeft + w, oval.fTop + w), w);
     } else {
         w /= 2;
         h /= 2;
         return EllipseEffect::Create(edgeType, SkPoint::Make(oval.fLeft + w, oval.fTop + h), w, h);
     }

     return nullptr;
 }
	/*
	* Copyright 2014 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "GrOvalEffect.h"

	#include "GrFragmentProcessor.h"
	#include "GrInvariantOutput.h"
	#include "SkRect.h"
	#include "glsl/GrGLSLFragmentProcessor.h"
	#include "glsl/GrGLSLFragmentShaderBuilder.h"
	#include "glsl/GrGLSLProgramBuilder.h"
	#include "glsl/GrGLSLProgramDataManager.h"

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

	class CircleEffect : public GrFragmentProcessor {
	public:
	static GrFragmentProcessor* Create(GrPrimitiveEdgeType, const SkPoint& center, SkScalar radius);

	virtual ~CircleEffect() {};

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

	const SkPoint& getCenter() const { return fCenter; }
	SkScalar getRadius() const { return fRadius; }

	GrPrimitiveEdgeType getEdgeType() const { return fEdgeType; }

	private:
	CircleEffect(GrPrimitiveEdgeType, const SkPoint& center, SkScalar radius);

	GrGLSLFragmentProcessor* onCreateGLInstance() const override;

	void onGetGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;

	bool onIsEqual(const GrFragmentProcessor&) const override;

	void onComputeInvariantOutput(GrInvariantOutput* inout) const override;

	SkPoint fCenter;
	SkScalar fRadius;
	GrPrimitiveEdgeType fEdgeType;

	GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

	typedef GrFragmentProcessor INHERITED;
	};

	GrFragmentProcessor* CircleEffect::Create(GrPrimitiveEdgeType edgeType, const SkPoint& center,
	SkScalar radius) {
	SkASSERT(radius >= 0);
	return new CircleEffect(edgeType, center, radius);
	}

	void CircleEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
	inout->mulByUnknownSingleComponent();
	}

	CircleEffect::CircleEffect(GrPrimitiveEdgeType edgeType, const SkPoint& c, SkScalar r)
	: fCenter(c)
	, fRadius(r)
	, fEdgeType(edgeType) {
	this->initClassID<CircleEffect>();
	this->setWillReadFragmentPosition();
	}

	bool CircleEffect::onIsEqual(const GrFragmentProcessor& other) const {
	const CircleEffect& ce = other.cast<CircleEffect>();
	return fEdgeType == ce.fEdgeType && fCenter == ce.fCenter && fRadius == ce.fRadius;
	}

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

	GR_DEFINE_FRAGMENT_PROCESSOR_TEST(CircleEffect);

	const GrFragmentProcessor* CircleEffect::TestCreate(GrProcessorTestData* d) {
	SkPoint center;
	center.fX = d->fRandom->nextRangeScalar(0.f, 1000.f);
	center.fY = d->fRandom->nextRangeScalar(0.f, 1000.f);
	SkScalar radius = d->fRandom->nextRangeF(0.f, 1000.f);
	GrPrimitiveEdgeType et;
	do {
	et = (GrPrimitiveEdgeType)d->fRandom->nextULessThan(kGrProcessorEdgeTypeCnt);
	} while (kHairlineAA_GrProcessorEdgeType == et);
	return CircleEffect::Create(et, center, radius);
	}

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

	class GLCircleEffect : public GrGLSLFragmentProcessor {
	public:
	GLCircleEffect(const GrProcessor&);

	virtual void emitCode(EmitArgs&) override;

	static inline void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*);

	protected:
	void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;

	private:
	GrGLSLProgramDataManager::UniformHandle fCircleUniform;
	SkPoint fPrevCenter;
	SkScalar fPrevRadius;

	typedef GrGLSLFragmentProcessor INHERITED;
	};

	GLCircleEffect::GLCircleEffect(const GrProcessor&) {
	fPrevRadius = -1.f;
	}

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

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

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

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

	void GLCircleEffect::GenKey(const GrProcessor& processor, const GrGLSLCaps&,
	GrProcessorKeyBuilder* b) {
	const CircleEffect& ce = processor.cast<CircleEffect>();
	b->add32(ce.getEdgeType());
	}

	void GLCircleEffect::onSetData(const GrGLSLProgramDataManager& pdman,
	const GrProcessor& processor) {
	const CircleEffect& ce = processor.cast<CircleEffect>();
	if (ce.getRadius() != fPrevRadius \|\| ce.getCenter() != fPrevCenter) {
	SkScalar radius = ce.getRadius();
	if (GrProcessorEdgeTypeIsInverseFill(ce.getEdgeType())) {
	radius -= 0.5f;
	} else {
	radius += 0.5f;
	}
	pdman.set4f(fCircleUniform, ce.getCenter().fX, ce.getCenter().fY, radius,
	SkScalarInvert(radius));
	fPrevCenter = ce.getCenter();
	fPrevRadius = ce.getRadius();
	}
	}

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

	void CircleEffect::onGetGLProcessorKey(const GrGLSLCaps& caps,
	GrProcessorKeyBuilder* b) const {
	GLCircleEffect::GenKey(*this, caps, b);
	}

	GrGLSLFragmentProcessor* CircleEffect::onCreateGLInstance() const {
	return new GLCircleEffect(*this);
	}

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

	class EllipseEffect : public GrFragmentProcessor {
	public:
	static GrFragmentProcessor* Create(GrPrimitiveEdgeType, const SkPoint& center, SkScalar rx,
	SkScalar ry);

	virtual ~EllipseEffect() {};

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

	const SkPoint& getCenter() const { return fCenter; }
	SkVector getRadii() const { return fRadii; }

	GrPrimitiveEdgeType getEdgeType() const { return fEdgeType; }

	private:
	EllipseEffect(GrPrimitiveEdgeType, const SkPoint& center, SkScalar rx, SkScalar ry);

	GrGLSLFragmentProcessor* onCreateGLInstance() const override;

	void onGetGLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder*) const override;

	bool onIsEqual(const GrFragmentProcessor&) const override;

	void onComputeInvariantOutput(GrInvariantOutput* inout) const override;

	SkPoint fCenter;
	SkVector fRadii;
	GrPrimitiveEdgeType fEdgeType;

	GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

	typedef GrFragmentProcessor INHERITED;
	};

	GrFragmentProcessor* EllipseEffect::Create(GrPrimitiveEdgeType edgeType,
	const SkPoint& center,
	SkScalar rx,
	SkScalar ry) {
	SkASSERT(rx >= 0 && ry >= 0);
	return new EllipseEffect(edgeType, center, rx, ry);
	}

	void EllipseEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
	inout->mulByUnknownSingleComponent();
	}

	EllipseEffect::EllipseEffect(GrPrimitiveEdgeType edgeType, const SkPoint& c, SkScalar rx, SkScalar ry)
	: fCenter(c)
	, fRadii(SkVector::Make(rx, ry))
	, fEdgeType(edgeType) {
	this->initClassID<EllipseEffect>();
	this->setWillReadFragmentPosition();
	}

	bool EllipseEffect::onIsEqual(const GrFragmentProcessor& other) const {
	const EllipseEffect& ee = other.cast<EllipseEffect>();
	return fEdgeType == ee.fEdgeType && fCenter == ee.fCenter && fRadii == ee.fRadii;
	}

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

	GR_DEFINE_FRAGMENT_PROCESSOR_TEST(EllipseEffect);

	const GrFragmentProcessor* EllipseEffect::TestCreate(GrProcessorTestData* d) {
	SkPoint center;
	center.fX = d->fRandom->nextRangeScalar(0.f, 1000.f);
	center.fY = d->fRandom->nextRangeScalar(0.f, 1000.f);
	SkScalar rx = d->fRandom->nextRangeF(0.f, 1000.f);
	SkScalar ry = d->fRandom->nextRangeF(0.f, 1000.f);
	GrPrimitiveEdgeType et;
	do {
	et = (GrPrimitiveEdgeType)d->fRandom->nextULessThan(kGrProcessorEdgeTypeCnt);
	} while (kHairlineAA_GrProcessorEdgeType == et);
	return EllipseEffect::Create(et, center, rx, ry);
	}

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

	class GLEllipseEffect : public GrGLSLFragmentProcessor {
	public:
	GLEllipseEffect(const GrProcessor&);

	virtual void emitCode(EmitArgs&) override;

	static inline void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*);

	protected:
	void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;

	private:
	GrGLSLProgramDataManager::UniformHandle fEllipseUniform;
	SkPoint fPrevCenter;
	SkVector fPrevRadii;

	typedef GrGLSLFragmentProcessor INHERITED;
	};

	GLEllipseEffect::GLEllipseEffect(const GrProcessor& effect) {
	fPrevRadii.fX = -1.f;
	}

	void GLEllipseEffect::emitCode(EmitArgs& args) {
	const EllipseEffect& ee = args.fFp.cast<EllipseEffect>();
	const char *ellipseName;
	// The ellipse uniform is (center.x, center.y, 1 / rx^2, 1 / ry^2)
	// The last two terms can underflow on mediump, so we use highp.
	fEllipseUniform = args.fBuilder->addUniform(GrGLSLProgramBuilder::kFragment_Visibility,
	kVec4f_GrSLType, kHigh_GrSLPrecision,
	"ellipse",
	&ellipseName);

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

	// d is the offset to the ellipse center
	fsBuilder->codeAppendf("\t\tvec2 d = %s.xy - %s.xy;\n", fragmentPos, ellipseName);
	fsBuilder->codeAppendf("\t\tvec2 Z = d * %s.zw;\n", ellipseName);
	// implicit is the evaluation of (x/rx)^2 + (y/ry)^2 - 1.
	fsBuilder->codeAppend("\t\tfloat implicit = dot(Z, d) - 1.0;\n");
	// grad_dot is the squared length of the gradient of the implicit.
	fsBuilder->codeAppendf("\t\tfloat grad_dot = 4.0 * dot(Z, Z);\n");
	// avoid calling inversesqrt on zero.
	fsBuilder->codeAppend("\t\tgrad_dot = max(grad_dot, 1.0e-4);\n");
	fsBuilder->codeAppendf("\t\tfloat approx_dist = implicit * inversesqrt(grad_dot);\n");

	switch (ee.getEdgeType()) {
	case kFillAA_GrProcessorEdgeType:
	fsBuilder->codeAppend("\t\tfloat alpha = clamp(0.5 - approx_dist, 0.0, 1.0);\n");
	break;
	case kInverseFillAA_GrProcessorEdgeType:
	fsBuilder->codeAppend("\t\tfloat alpha = clamp(0.5 + approx_dist, 0.0, 1.0);\n");
	break;
	case kFillBW_GrProcessorEdgeType:
	fsBuilder->codeAppend("\t\tfloat alpha = approx_dist > 0.0 ? 0.0 : 1.0;\n");
	break;
	case kInverseFillBW_GrProcessorEdgeType:
	fsBuilder->codeAppend("\t\tfloat alpha = approx_dist > 0.0 ? 1.0 : 0.0;\n");
	break;
	case kHairlineAA_GrProcessorEdgeType:
	SkFAIL("Hairline not expected here.");
	}

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

	void GLEllipseEffect::GenKey(const GrProcessor& effect, const GrGLSLCaps&,
	GrProcessorKeyBuilder* b) {
	const EllipseEffect& ee = effect.cast<EllipseEffect>();
	b->add32(ee.getEdgeType());
	}

	void GLEllipseEffect::onSetData(const GrGLSLProgramDataManager& pdman,
	const GrProcessor& effect) {
	const EllipseEffect& ee = effect.cast<EllipseEffect>();
	if (ee.getRadii() != fPrevRadii \|\| ee.getCenter() != fPrevCenter) {
	SkScalar invRXSqd = 1.f / (ee.getRadii().fX * ee.getRadii().fX);
	SkScalar invRYSqd = 1.f / (ee.getRadii().fY * ee.getRadii().fY);
	pdman.set4f(fEllipseUniform, ee.getCenter().fX, ee.getCenter().fY, invRXSqd, invRYSqd);
	fPrevCenter = ee.getCenter();
	fPrevRadii = ee.getRadii();
	}
	}

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

	void EllipseEffect::onGetGLProcessorKey(const GrGLSLCaps& caps,
	GrProcessorKeyBuilder* b) const {
	GLEllipseEffect::GenKey(*this, caps, b);
	}

	GrGLSLFragmentProcessor* EllipseEffect::onCreateGLInstance() const {
	return new GLEllipseEffect(*this);
	}

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

	GrFragmentProcessor* GrOvalEffect::Create(GrPrimitiveEdgeType edgeType, const SkRect& oval) {
	if (kHairlineAA_GrProcessorEdgeType == edgeType) {
	return nullptr;
	}
	SkScalar w = oval.width();
	SkScalar h = oval.height();
	if (SkScalarNearlyEqual(w, h)) {
	w /= 2;
	return CircleEffect::Create(edgeType, SkPoint::Make(oval.fLeft + w, oval.fTop + w), w);
	} else {
	w /= 2;
	h /= 2;
	return EllipseEffect::Create(edgeType, SkPoint::Make(oval.fLeft + w, oval.fTop + h), w, h);
	}

	return nullptr;
	}