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 "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProgramDataManager.h"
 #include "glsl/GrGLSLUniformHandler.h"
 #include "glsl/GrGLSLXferProcessor.h"

 static const bool gUseUnpremul = false;

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

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

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

 class GLArithmeticFP : public GrGLSLFragmentProcessor {
 public:
     GLArithmeticFP(const GrArithmeticFP& arithmeticFP)
         : fEnforcePMColor(arithmeticFP.enforcePMColor()) {}

     ~GLArithmeticFP() override {}

     void emitCode(EmitArgs& args) override {
         GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
         SkString dstColor("dstColor");
         this->emitChild(0, nullptr, &dstColor, args);

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

         add_arithmetic_code(fragBuilder,
                             args.fInputColor,
                             dstColor.c_str(),
                             args.fOutputColor,
                             kUni,
                             fEnforcePMColor);
     }

     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);
     }

 protected:
     void onSetData(const GrGLSLProgramDataManager& 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();
     }

 private:
     GrGLSLProgramDataManager::UniformHandle fKUni;
     bool fEnforcePMColor;

     typedef GrGLSLFragmentProcessor INHERITED;
 };

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

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

     SkASSERT(dst);
     SkDEBUGCODE(int dstIndex = )this->registerChildProcessor(dst);
     SkASSERT(0 == dstIndex);
 }

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

 GrGLSLFragmentProcessor* GrArithmeticFP::onCreateGLSLInstance() const {
     return new 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);
 }

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

 const GrFragmentProcessor* GrArithmeticFP::TestCreate(GrProcessorTestData* d) {
     float k1 = d->fRandom->nextF();
     float k2 = d->fRandom->nextF();
     float k3 = d->fRandom->nextF();
     float k4 = d->fRandom->nextF();
     bool enforcePMColor = d->fRandom->nextBool();

     SkAutoTUnref<const GrFragmentProcessor> dst(GrProcessorUnitTest::CreateChildFP(d));
     return new GrArithmeticFP(k1, k2, k3, k4, enforcePMColor, dst);
 }

 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrArithmeticFP);

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

 class ArithmeticXP : public GrXferProcessor {
 public:
     ArithmeticXP(const DstTexture*, bool hasMixedSamples,
                  float k1, float k2, float k3, float k4, bool enforcePMColor);

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

     GrGLSLXferProcessor* createGLSLInstance() const override;

     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:
     GrXferProcessor::OptFlags onGetOptimizations(const GrPipelineOptimizations& optimizations,
                                                  bool doesStencilWrite,
                                                  GrColor* overrideColor,
                                                  const GrCaps& caps) const override;

     void onGetGLSLProcessorKey(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 GrGLSLXferProcessor {
 public:
     GLArithmeticXP(const ArithmeticXP& arithmeticXP)
         : fEnforcePMColor(arithmeticXP.enforcePMColor()) {
     }

     ~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 emitBlendCodeForDstRead(GrGLSLXPFragmentBuilder* fragBuilder,
                                  GrGLSLUniformHandler* uniformHandler,
                                  const char* srcColor,
                                  const char* srcCoverage,
                                  const char* dstColor,
                                  const char* outColor,
                                  const char* outColorSecondary,
                                  const GrXferProcessor& proc) override {
         fKUni = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
                                            kVec4f_GrSLType, kDefault_GrSLPrecision,
                                            "k");
         const char* kUni = uniformHandler->getUniformCStr(fKUni);

         add_arithmetic_code(fragBuilder, srcColor, dstColor, outColor, kUni, fEnforcePMColor);

         // Apply coverage.
         INHERITED::DefaultCoverageModulation(fragBuilder, srcCoverage, dstColor, outColor,
                                              outColorSecondary, proc);
     }

     void onSetData(const GrGLSLProgramDataManager& 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();
     };

     GrGLSLProgramDataManager::UniformHandle fKUni;
     bool fEnforcePMColor;

     typedef GrGLSLXferProcessor INHERITED;
 };

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

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

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

 GrGLSLXferProcessor* ArithmeticXP::createGLSLInstance() const { return new GLArithmeticXP(*this); }

 GrXferProcessor::OptFlags ArithmeticXP::onGetOptimizations(
                                                        const GrPipelineOptimizations& optimizations,
                                                        bool doesStencilWrite,
                                                        GrColor* overrideColor,
                                                        const GrCaps& caps) const {
    return GrXferProcessor::kNone_OptFlags;
 }

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

 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 GrPipelineOptimizations& optimizations,
                                              bool hasMixedSamples,
                                              const DstTexture* dstTexture) const {
     return new ArithmeticXP(dstTexture, hasMixedSamples, fK1, fK2, fK3, fK4, fEnforcePMColor);
 }


 void GrArithmeticXPFactory::getInvariantBlendedColor(const GrProcOptInfo& colorPOI,
                                                      InvariantBlendedColor* blendedColor) const {
     blendedColor->fWillBlendWithDst = true;

     // TODO: We could try to optimize this more. For example if 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).
     blendedColor->fKnownColorFlags = kNone_GrColorComponentFlags;
 }

 GR_DEFINE_XP_FACTORY_TEST(GrArithmeticXPFactory);

 const GrXPFactory* GrArithmeticXPFactory::TestCreate(GrProcessorTestData* d) {
     float k1 = d->fRandom->nextF();
     float k2 = d->fRandom->nextF();
     float k3 = d->fRandom->nextF();
     float k4 = d->fRandom->nextF();
     bool enforcePMColor = d->fRandom->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 "glsl/GrGLSLFragmentProcessor.h"
	#include "glsl/GrGLSLFragmentShaderBuilder.h"
	#include "glsl/GrGLSLProgramDataManager.h"
	#include "glsl/GrGLSLUniformHandler.h"
	#include "glsl/GrGLSLXferProcessor.h"

	static const bool gUseUnpremul = false;

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

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

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

	class GLArithmeticFP : public GrGLSLFragmentProcessor {
	public:
	GLArithmeticFP(const GrArithmeticFP& arithmeticFP)
	: fEnforcePMColor(arithmeticFP.enforcePMColor()) {}

	~GLArithmeticFP() override {}

	void emitCode(EmitArgs& args) override {
	GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
	SkString dstColor("dstColor");
	this->emitChild(0, nullptr, &dstColor, args);

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

	add_arithmetic_code(fragBuilder,
	args.fInputColor,
	dstColor.c_str(),
	args.fOutputColor,
	kUni,
	fEnforcePMColor);
	}

	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);
	}

	protected:
	void onSetData(const GrGLSLProgramDataManager& 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();
	}

	private:
	GrGLSLProgramDataManager::UniformHandle fKUni;
	bool fEnforcePMColor;

	typedef GrGLSLFragmentProcessor INHERITED;
	};

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

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

	SkASSERT(dst);
	SkDEBUGCODE(int dstIndex = )this->registerChildProcessor(dst);
	SkASSERT(0 == dstIndex);
	}

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

	GrGLSLFragmentProcessor* GrArithmeticFP::onCreateGLSLInstance() const {
	return new 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);
	}

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

	const GrFragmentProcessor* GrArithmeticFP::TestCreate(GrProcessorTestData* d) {
	float k1 = d->fRandom->nextF();
	float k2 = d->fRandom->nextF();
	float k3 = d->fRandom->nextF();
	float k4 = d->fRandom->nextF();
	bool enforcePMColor = d->fRandom->nextBool();

	SkAutoTUnref<const GrFragmentProcessor> dst(GrProcessorUnitTest::CreateChildFP(d));
	return new GrArithmeticFP(k1, k2, k3, k4, enforcePMColor, dst);
	}

	GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrArithmeticFP);

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

	class ArithmeticXP : public GrXferProcessor {
	public:
	ArithmeticXP(const DstTexture*, bool hasMixedSamples,
	float k1, float k2, float k3, float k4, bool enforcePMColor);

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

	GrGLSLXferProcessor* createGLSLInstance() const override;

	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:
	GrXferProcessor::OptFlags onGetOptimizations(const GrPipelineOptimizations& optimizations,
	bool doesStencilWrite,
	GrColor* overrideColor,
	const GrCaps& caps) const override;

	void onGetGLSLProcessorKey(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 GrGLSLXferProcessor {
	public:
	GLArithmeticXP(const ArithmeticXP& arithmeticXP)
	: fEnforcePMColor(arithmeticXP.enforcePMColor()) {
	}

	~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 emitBlendCodeForDstRead(GrGLSLXPFragmentBuilder* fragBuilder,
	GrGLSLUniformHandler* uniformHandler,
	const char* srcColor,
	const char* srcCoverage,
	const char* dstColor,
	const char* outColor,
	const char* outColorSecondary,
	const GrXferProcessor& proc) override {
	fKUni = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
	kVec4f_GrSLType, kDefault_GrSLPrecision,
	"k");
	const char* kUni = uniformHandler->getUniformCStr(fKUni);

	add_arithmetic_code(fragBuilder, srcColor, dstColor, outColor, kUni, fEnforcePMColor);

	// Apply coverage.
	INHERITED::DefaultCoverageModulation(fragBuilder, srcCoverage, dstColor, outColor,
	outColorSecondary, proc);
	}

	void onSetData(const GrGLSLProgramDataManager& 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();
	};

	GrGLSLProgramDataManager::UniformHandle fKUni;
	bool fEnforcePMColor;

	typedef GrGLSLXferProcessor INHERITED;
	};

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

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

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

	GrGLSLXferProcessor* ArithmeticXP::createGLSLInstance() const { return new GLArithmeticXP(*this); }

	GrXferProcessor::OptFlags ArithmeticXP::onGetOptimizations(
	const GrPipelineOptimizations& optimizations,
	bool doesStencilWrite,
	GrColor* overrideColor,
	const GrCaps& caps) const {
	return GrXferProcessor::kNone_OptFlags;
	}

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

	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 GrPipelineOptimizations& optimizations,
	bool hasMixedSamples,
	const DstTexture* dstTexture) const {
	return new ArithmeticXP(dstTexture, hasMixedSamples, fK1, fK2, fK3, fK4, fEnforcePMColor);
	}


	void GrArithmeticXPFactory::getInvariantBlendedColor(const GrProcOptInfo& colorPOI,
	InvariantBlendedColor* blendedColor) const {
	blendedColor->fWillBlendWithDst = true;

	// TODO: We could try to optimize this more. For example if 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).
	blendedColor->fKnownColorFlags = kNone_GrColorComponentFlags;
	}

	GR_DEFINE_XP_FACTORY_TEST(GrArithmeticXPFactory);

	const GrXPFactory* GrArithmeticXPFactory::TestCreate(GrProcessorTestData* d) {
	float k1 = d->fRandom->nextF();
	float k2 = d->fRandom->nextF();
	float k3 = d->fRandom->nextF();
	float k4 = d->fRandom->nextF();
	bool enforcePMColor = d->fRandom->nextBool();

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

	#endif