src/effects/SkArithmeticMode_gpu.cpp - skia - Git at Google

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkArithmeticMode_gpu.h"

 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "GrFragmentProcessor.h"
 #include "GrInvariantOutput.h"
 #include "GrProcessor.h"
 #include "GrTexture.h"
 #include "gl/GrGLCaps.h"
 #include "gl/GrGLProcessor.h"
 #include "gl/GrGLProgramDataManager.h"
 #include "gl/builders/GrGLProgramBuilder.h"

 static const bool gUseUnpremul = false;

 static void add_arithmetic_code(GrGLFragmentBuilder* fsBuilder,
                                 const char* inputColor,
                                 const char* dstColor,
                                 const char* outputColor,
                                 const char* kUni,
                                 bool enforcePMColor) {
     // We don't try to optimize for this case at all
     if (NULL == inputColor) {
         fsBuilder->codeAppend("const vec4 src = vec4(1);");
     } else {
         fsBuilder->codeAppendf("vec4 src = %s;", inputColor);
         if (gUseUnpremul) {
             fsBuilder->codeAppend("src.rgb = clamp(src.rgb / src.a, 0.0, 1.0);");
         }
     }

     fsBuilder->codeAppendf("vec4 dst = %s;", dstColor);
     if (gUseUnpremul) {
         fsBuilder->codeAppend("dst.rgb = clamp(dst.rgb / dst.a, 0.0, 1.0);");
     }

     fsBuilder->codeAppendf("%s = %s.x * src * dst + %s.y * src + %s.z * dst + %s.w;",
                            outputColor, kUni, kUni, kUni, kUni);
     fsBuilder->codeAppendf("%s = clamp(%s, 0.0, 1.0);\n", outputColor, outputColor);
     if (gUseUnpremul) {
         fsBuilder->codeAppendf("%s.rgb *= %s.a;", outputColor, outputColor);
     } else if (enforcePMColor) {
         fsBuilder->codeAppendf("%s.rgb = min(%s.rgb, %s.a);",
                                outputColor, outputColor, outputColor);
     }
 }

 class GLArithmeticFP : public GrGLFragmentProcessor {
 public:
     GLArithmeticFP(const GrProcessor&)
         : fEnforcePMColor(true) {
     }

     ~GLArithmeticFP() override {}

     void emitCode(GrGLFPBuilder* builder,
                   const GrFragmentProcessor& fp,
                   const char* outputColor,
                   const char* inputColor,
                   const TransformedCoordsArray& coords,
                   const TextureSamplerArray& samplers) override {
         GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
         fsBuilder->codeAppend("vec4 bgColor = ");
         fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType());
         fsBuilder->codeAppendf(";");
         const char* dstColor = "bgColor";

         fKUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                     kVec4f_GrSLType, kDefault_GrSLPrecision,
                                     "k");
         const char* kUni = builder->getUniformCStr(fKUni);

         add_arithmetic_code(fsBuilder, inputColor, dstColor, outputColor, kUni, fEnforcePMColor);
     }

     void setData(const GrGLProgramDataManager& pdman, const GrProcessor& proc) override {
         const GrArithmeticFP& arith = proc.cast<GrArithmeticFP>();
         pdman.set4f(fKUni, arith.k1(), arith.k2(), arith.k3(), arith.k4());
         fEnforcePMColor = arith.enforcePMColor();
     }

     static void GenKey(const GrProcessor& proc, const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) {
         const GrArithmeticFP& arith = proc.cast<GrArithmeticFP>();
         uint32_t key = arith.enforcePMColor() ? 1 : 0;
         b->add32(key);
     }

 private:
     GrGLProgramDataManager::UniformHandle fKUni;
     bool fEnforcePMColor;

     typedef GrGLFragmentProcessor INHERITED;
 };

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

 GrArithmeticFP::GrArithmeticFP(float k1, float k2, float k3, float k4,
                                bool enforcePMColor, GrTexture* background)
   : fK1(k1), fK2(k2), fK3(k3), fK4(k4), fEnforcePMColor(enforcePMColor) {
     this->initClassID<GrArithmeticFP>();

     SkASSERT(background);

     fBackgroundTransform.reset(kLocal_GrCoordSet, background,
                                GrTextureParams::kNone_FilterMode);
     this->addCoordTransform(&fBackgroundTransform);
     fBackgroundAccess.reset(background);
     this->addTextureAccess(&fBackgroundAccess);
 }

 void GrArithmeticFP::getGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const {
     GLArithmeticFP::GenKey(*this, caps, b);
 }

 GrGLFragmentProcessor* GrArithmeticFP::createGLInstance() const {
     return SkNEW_ARGS(GLArithmeticFP, (*this));
 }

 bool GrArithmeticFP::onIsEqual(const GrFragmentProcessor& fpBase) const {
     const GrArithmeticFP& fp = fpBase.cast<GrArithmeticFP>();
     return fK1 == fp.fK1 &&
            fK2 == fp.fK2 &&
            fK3 == fp.fK3 &&
            fK4 == fp.fK4 &&
            fEnforcePMColor == fp.fEnforcePMColor;
 }

 void GrArithmeticFP::onComputeInvariantOutput(GrInvariantOutput* inout) const {
     // TODO: optimize this
     inout->setToUnknown(GrInvariantOutput::kWill_ReadInput);
 }

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

 GrFragmentProcessor* GrArithmeticFP::TestCreate(SkRandom* rand,
                                                 GrContext*,
                                                 const GrCaps&,
                                                 GrTexture* textures[]) {
     float k1 = rand->nextF();
     float k2 = rand->nextF();
     float k3 = rand->nextF();
     float k4 = rand->nextF();
     bool enforcePMColor = rand->nextBool();

     return SkNEW_ARGS(GrArithmeticFP, (k1, k2, k3, k4, enforcePMColor, textures[0]));
 }

 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrArithmeticFP);

 ///////////////////////////////////////////////////////////////////////////////
 // Xfer Processor
 ///////////////////////////////////////////////////////////////////////////////

 class ArithmeticXP : public GrXferProcessor {
 public:
     static GrXferProcessor* Create(float k1, float k2, float k3, float k4, bool enforcePMColor,
                                    const GrDeviceCoordTexture* dstCopy,
                                    bool willReadDstColor) {
         return SkNEW_ARGS(ArithmeticXP, (k1, k2, k3, k4, enforcePMColor, dstCopy,
                                          willReadDstColor));
     }

     ~ArithmeticXP() override {};

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

     GrGLXferProcessor* createGLInstance() const override;

     bool hasSecondaryOutput() const override { return false; }

     float k1() const { return fK1; }
     float k2() const { return fK2; }
     float k3() const { return fK3; }
     float k4() const { return fK4; }
     bool enforcePMColor() const { return fEnforcePMColor; }

 private:
     ArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor,
                    const GrDeviceCoordTexture* dstCopy, bool willReadDstColor);

     GrXferProcessor::OptFlags onGetOptimizations(const GrProcOptInfo& colorPOI,
                                                  const GrProcOptInfo& coveragePOI,
                                                  bool doesStencilWrite,
                                                  GrColor* overrideColor,
                                                  const GrCaps& caps) override;

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

     bool onIsEqual(const GrXferProcessor& xpBase) const override {
         const ArithmeticXP& xp = xpBase.cast<ArithmeticXP>();
         if (fK1 != xp.fK1 ||
             fK2 != xp.fK2 ||
             fK3 != xp.fK3 ||
             fK4 != xp.fK4 ||
             fEnforcePMColor != xp.fEnforcePMColor) {
             return false;
         }
         return true;
     }

     float                       fK1, fK2, fK3, fK4;
     bool                        fEnforcePMColor;

     typedef GrXferProcessor INHERITED;
 };

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

 class GLArithmeticXP : public GrGLXferProcessor {
 public:
     GLArithmeticXP(const GrProcessor&)
         : fEnforcePMColor(true) {
     }

     ~GLArithmeticXP() override {}

     static void GenKey(const GrProcessor& processor, const GrGLSLCaps& caps,
                        GrProcessorKeyBuilder* b) {
         const ArithmeticXP& arith = processor.cast<ArithmeticXP>();
         uint32_t key = arith.enforcePMColor() ? 1 : 0;
         b->add32(key);
     }

 private:
     void onEmitCode(const EmitArgs& args) override {
         GrGLXPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();

         const char* dstColor = fsBuilder->dstColor();

         fKUni = args.fPB->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                      kVec4f_GrSLType, kDefault_GrSLPrecision,
                                      "k");
         const char* kUni = args.fPB->getUniformCStr(fKUni);

         add_arithmetic_code(fsBuilder, args.fInputColor, dstColor, args.fOutputPrimary, kUni,
                             fEnforcePMColor);

         fsBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;",
                                args.fOutputPrimary, args.fOutputPrimary, args.fInputCoverage,
                                args.fInputCoverage, dstColor);
     }

     void onSetData(const GrGLProgramDataManager& pdman,
                    const GrXferProcessor& processor) override {
         const ArithmeticXP& arith = processor.cast<ArithmeticXP>();
         pdman.set4f(fKUni, arith.k1(), arith.k2(), arith.k3(), arith.k4());
         fEnforcePMColor = arith.enforcePMColor();
     };

     GrGLProgramDataManager::UniformHandle fKUni;
     bool fEnforcePMColor;

     typedef GrGLXferProcessor INHERITED;
 };

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

 ArithmeticXP::ArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor,
                            const GrDeviceCoordTexture* dstCopy, bool willReadDstColor)
     : INHERITED(dstCopy, willReadDstColor)
     , fK1(k1)
     , fK2(k2)
     , fK3(k3)
     , fK4(k4)
     , fEnforcePMColor(enforcePMColor) {
     this->initClassID<ArithmeticXP>();
 }

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

 GrGLXferProcessor* ArithmeticXP::createGLInstance() const {
     return SkNEW_ARGS(GLArithmeticXP, (*this));
 }

 GrXferProcessor::OptFlags ArithmeticXP::onGetOptimizations(const GrProcOptInfo& colorPOI,
                                                            const GrProcOptInfo& coveragePOI,
                                                            bool doesStencilWrite,
                                                            GrColor* overrideColor,
                                                            const GrCaps& caps) {
    return GrXferProcessor::kNone_Opt;
 }

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

 GrArithmeticXPFactory::GrArithmeticXPFactory(float k1, float k2, float k3, float k4,
                                              bool enforcePMColor)
     : fK1(k1), fK2(k2), fK3(k3), fK4(k4), fEnforcePMColor(enforcePMColor) {
     this->initClassID<GrArithmeticXPFactory>();
 }

 GrXferProcessor*
 GrArithmeticXPFactory::onCreateXferProcessor(const GrCaps& caps,
                                              const GrProcOptInfo& colorPOI,
                                              const GrProcOptInfo& coveragePOI,
                                              const GrDeviceCoordTexture* dstCopy) const {
     return ArithmeticXP::Create(fK1, fK2, fK3, fK4, fEnforcePMColor, dstCopy,
                                 this->willReadDstColor(caps, colorPOI, coveragePOI));
 }


 void GrArithmeticXPFactory::getInvariantOutput(const GrProcOptInfo& colorPOI,
                                                const GrProcOptInfo& coveragePOI,
                                                GrXPFactory::InvariantOutput* output) const {
     output->fWillBlendWithDst = true;

     // TODO: We could try to optimize this more. For example if we have solid coverage and fK1 and
     // fK3 are zero, then we won't be blending the color with dst at all so we can know what the
     // output color is (up to the valid color components passed in).
     output->fBlendedColorFlags = 0;
 }

 GR_DEFINE_XP_FACTORY_TEST(GrArithmeticXPFactory);

 GrXPFactory* GrArithmeticXPFactory::TestCreate(SkRandom* random,
                                                GrContext*,
                                                const GrCaps&,
                                                GrTexture*[]) {
     float k1 = random->nextF();
     float k2 = random->nextF();
     float k3 = random->nextF();
     float k4 = random->nextF();
     bool enforcePMColor = random->nextBool();

     return GrArithmeticXPFactory::Create(k1, k2, k3, k4, enforcePMColor);
 }

 #endif
	/*
	* Copyright 2015 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkArithmeticMode_gpu.h"

	#if SK_SUPPORT_GPU
	#include "GrContext.h"
	#include "GrFragmentProcessor.h"
	#include "GrInvariantOutput.h"
	#include "GrProcessor.h"
	#include "GrTexture.h"
	#include "gl/GrGLCaps.h"
	#include "gl/GrGLProcessor.h"
	#include "gl/GrGLProgramDataManager.h"
	#include "gl/builders/GrGLProgramBuilder.h"

	static const bool gUseUnpremul = false;

	static void add_arithmetic_code(GrGLFragmentBuilder* fsBuilder,
	const char* inputColor,
	const char* dstColor,
	const char* outputColor,
	const char* kUni,
	bool enforcePMColor) {
	// We don't try to optimize for this case at all
	if (NULL == inputColor) {
	fsBuilder->codeAppend("const vec4 src = vec4(1);");
	} else {
	fsBuilder->codeAppendf("vec4 src = %s;", inputColor);
	if (gUseUnpremul) {
	fsBuilder->codeAppend("src.rgb = clamp(src.rgb / src.a, 0.0, 1.0);");
	}
	}

	fsBuilder->codeAppendf("vec4 dst = %s;", dstColor);
	if (gUseUnpremul) {
	fsBuilder->codeAppend("dst.rgb = clamp(dst.rgb / dst.a, 0.0, 1.0);");
	}

	fsBuilder->codeAppendf("%s = %s.x * src * dst + %s.y * src + %s.z * dst + %s.w;",
	outputColor, kUni, kUni, kUni, kUni);
	fsBuilder->codeAppendf("%s = clamp(%s, 0.0, 1.0);\n", outputColor, outputColor);
	if (gUseUnpremul) {
	fsBuilder->codeAppendf("%s.rgb *= %s.a;", outputColor, outputColor);
	} else if (enforcePMColor) {
	fsBuilder->codeAppendf("%s.rgb = min(%s.rgb, %s.a);",
	outputColor, outputColor, outputColor);
	}
	}

	class GLArithmeticFP : public GrGLFragmentProcessor {
	public:
	GLArithmeticFP(const GrProcessor&)
	: fEnforcePMColor(true) {
	}

	~GLArithmeticFP() override {}

	void emitCode(GrGLFPBuilder* builder,
	const GrFragmentProcessor& fp,
	const char* outputColor,
	const char* inputColor,
	const TransformedCoordsArray& coords,
	const TextureSamplerArray& samplers) override {
	GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
	fsBuilder->codeAppend("vec4 bgColor = ");
	fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType());
	fsBuilder->codeAppendf(";");
	const char* dstColor = "bgColor";

	fKUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
	kVec4f_GrSLType, kDefault_GrSLPrecision,
	"k");
	const char* kUni = builder->getUniformCStr(fKUni);

	add_arithmetic_code(fsBuilder, inputColor, dstColor, outputColor, kUni, fEnforcePMColor);
	}

	void setData(const GrGLProgramDataManager& pdman, const GrProcessor& proc) override {
	const GrArithmeticFP& arith = proc.cast<GrArithmeticFP>();
	pdman.set4f(fKUni, arith.k1(), arith.k2(), arith.k3(), arith.k4());
	fEnforcePMColor = arith.enforcePMColor();
	}

	static void GenKey(const GrProcessor& proc, const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) {
	const GrArithmeticFP& arith = proc.cast<GrArithmeticFP>();
	uint32_t key = arith.enforcePMColor() ? 1 : 0;
	b->add32(key);
	}

	private:
	GrGLProgramDataManager::UniformHandle fKUni;
	bool fEnforcePMColor;

	typedef GrGLFragmentProcessor INHERITED;
	};

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

	GrArithmeticFP::GrArithmeticFP(float k1, float k2, float k3, float k4,
	bool enforcePMColor, GrTexture* background)
	: fK1(k1), fK2(k2), fK3(k3), fK4(k4), fEnforcePMColor(enforcePMColor) {
	this->initClassID<GrArithmeticFP>();

	SkASSERT(background);

	fBackgroundTransform.reset(kLocal_GrCoordSet, background,
	GrTextureParams::kNone_FilterMode);
	this->addCoordTransform(&fBackgroundTransform);
	fBackgroundAccess.reset(background);
	this->addTextureAccess(&fBackgroundAccess);
	}

	void GrArithmeticFP::getGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const {
	GLArithmeticFP::GenKey(*this, caps, b);
	}

	GrGLFragmentProcessor* GrArithmeticFP::createGLInstance() const {
	return SkNEW_ARGS(GLArithmeticFP, (*this));
	}

	bool GrArithmeticFP::onIsEqual(const GrFragmentProcessor& fpBase) const {
	const GrArithmeticFP& fp = fpBase.cast<GrArithmeticFP>();
	return fK1 == fp.fK1 &&
	fK2 == fp.fK2 &&
	fK3 == fp.fK3 &&
	fK4 == fp.fK4 &&
	fEnforcePMColor == fp.fEnforcePMColor;
	}

	void GrArithmeticFP::onComputeInvariantOutput(GrInvariantOutput* inout) const {
	// TODO: optimize this
	inout->setToUnknown(GrInvariantOutput::kWill_ReadInput);
	}

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

	GrFragmentProcessor* GrArithmeticFP::TestCreate(SkRandom* rand,
	GrContext*,
	const GrCaps&,
	GrTexture* textures[]) {
	float k1 = rand->nextF();
	float k2 = rand->nextF();
	float k3 = rand->nextF();
	float k4 = rand->nextF();
	bool enforcePMColor = rand->nextBool();

	return SkNEW_ARGS(GrArithmeticFP, (k1, k2, k3, k4, enforcePMColor, textures[0]));
	}

	GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrArithmeticFP);

	///////////////////////////////////////////////////////////////////////////////
	// Xfer Processor
	///////////////////////////////////////////////////////////////////////////////

	class ArithmeticXP : public GrXferProcessor {
	public:
	static GrXferProcessor* Create(float k1, float k2, float k3, float k4, bool enforcePMColor,
	const GrDeviceCoordTexture* dstCopy,
	bool willReadDstColor) {
	return SkNEW_ARGS(ArithmeticXP, (k1, k2, k3, k4, enforcePMColor, dstCopy,
	willReadDstColor));
	}

	~ArithmeticXP() override {};

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

	GrGLXferProcessor* createGLInstance() const override;

	bool hasSecondaryOutput() const override { return false; }

	float k1() const { return fK1; }
	float k2() const { return fK2; }
	float k3() const { return fK3; }
	float k4() const { return fK4; }
	bool enforcePMColor() const { return fEnforcePMColor; }

	private:
	ArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor,
	const GrDeviceCoordTexture* dstCopy, bool willReadDstColor);

	GrXferProcessor::OptFlags onGetOptimizations(const GrProcOptInfo& colorPOI,
	const GrProcOptInfo& coveragePOI,
	bool doesStencilWrite,
	GrColor* overrideColor,
	const GrCaps& caps) override;

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

	bool onIsEqual(const GrXferProcessor& xpBase) const override {
	const ArithmeticXP& xp = xpBase.cast<ArithmeticXP>();
	if (fK1 != xp.fK1 \|\|
	fK2 != xp.fK2 \|\|
	fK3 != xp.fK3 \|\|
	fK4 != xp.fK4 \|\|
	fEnforcePMColor != xp.fEnforcePMColor) {
	return false;
	}
	return true;
	}

	float fK1, fK2, fK3, fK4;
	bool fEnforcePMColor;

	typedef GrXferProcessor INHERITED;
	};

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

	class GLArithmeticXP : public GrGLXferProcessor {
	public:
	GLArithmeticXP(const GrProcessor&)
	: fEnforcePMColor(true) {
	}

	~GLArithmeticXP() override {}

	static void GenKey(const GrProcessor& processor, const GrGLSLCaps& caps,
	GrProcessorKeyBuilder* b) {
	const ArithmeticXP& arith = processor.cast<ArithmeticXP>();
	uint32_t key = arith.enforcePMColor() ? 1 : 0;
	b->add32(key);
	}

	private:
	void onEmitCode(const EmitArgs& args) override {
	GrGLXPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();

	const char* dstColor = fsBuilder->dstColor();

	fKUni = args.fPB->addUniform(GrGLProgramBuilder::kFragment_Visibility,
	kVec4f_GrSLType, kDefault_GrSLPrecision,
	"k");
	const char* kUni = args.fPB->getUniformCStr(fKUni);

	add_arithmetic_code(fsBuilder, args.fInputColor, dstColor, args.fOutputPrimary, kUni,
	fEnforcePMColor);

	fsBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;",
	args.fOutputPrimary, args.fOutputPrimary, args.fInputCoverage,
	args.fInputCoverage, dstColor);
	}

	void onSetData(const GrGLProgramDataManager& pdman,
	const GrXferProcessor& processor) override {
	const ArithmeticXP& arith = processor.cast<ArithmeticXP>();
	pdman.set4f(fKUni, arith.k1(), arith.k2(), arith.k3(), arith.k4());
	fEnforcePMColor = arith.enforcePMColor();
	};

	GrGLProgramDataManager::UniformHandle fKUni;
	bool fEnforcePMColor;

	typedef GrGLXferProcessor INHERITED;
	};

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

	ArithmeticXP::ArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor,
	const GrDeviceCoordTexture* dstCopy, bool willReadDstColor)
	: INHERITED(dstCopy, willReadDstColor)
	, fK1(k1)
	, fK2(k2)
	, fK3(k3)
	, fK4(k4)
	, fEnforcePMColor(enforcePMColor) {
	this->initClassID<ArithmeticXP>();
	}

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

	GrGLXferProcessor* ArithmeticXP::createGLInstance() const {
	return SkNEW_ARGS(GLArithmeticXP, (*this));
	}

	GrXferProcessor::OptFlags ArithmeticXP::onGetOptimizations(const GrProcOptInfo& colorPOI,
	const GrProcOptInfo& coveragePOI,
	bool doesStencilWrite,
	GrColor* overrideColor,
	const GrCaps& caps) {
	return GrXferProcessor::kNone_Opt;
	}

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

	GrArithmeticXPFactory::GrArithmeticXPFactory(float k1, float k2, float k3, float k4,
	bool enforcePMColor)
	: fK1(k1), fK2(k2), fK3(k3), fK4(k4), fEnforcePMColor(enforcePMColor) {
	this->initClassID<GrArithmeticXPFactory>();
	}

	GrXferProcessor*
	GrArithmeticXPFactory::onCreateXferProcessor(const GrCaps& caps,
	const GrProcOptInfo& colorPOI,
	const GrProcOptInfo& coveragePOI,
	const GrDeviceCoordTexture* dstCopy) const {
	return ArithmeticXP::Create(fK1, fK2, fK3, fK4, fEnforcePMColor, dstCopy,
	this->willReadDstColor(caps, colorPOI, coveragePOI));
	}


	void GrArithmeticXPFactory::getInvariantOutput(const GrProcOptInfo& colorPOI,
	const GrProcOptInfo& coveragePOI,
	GrXPFactory::InvariantOutput* output) const {
	output->fWillBlendWithDst = true;

	// TODO: We could try to optimize this more. For example if we have solid coverage and fK1 and
	// fK3 are zero, then we won't be blending the color with dst at all so we can know what the
	// output color is (up to the valid color components passed in).
	output->fBlendedColorFlags = 0;
	}

	GR_DEFINE_XP_FACTORY_TEST(GrArithmeticXPFactory);

	GrXPFactory* GrArithmeticXPFactory::TestCreate(SkRandom* random,
	GrContext*,
	const GrCaps&,
	GrTexture*[]) {
	float k1 = random->nextF();
	float k2 = random->nextF();
	float k3 = random->nextF();
	float k4 = random->nextF();
	bool enforcePMColor = random->nextBool();

	return GrArithmeticXPFactory::Create(k1, k2, k3, k4, enforcePMColor);
	}

	#endif