src/gpu/effects/GrMatrixConvolutionEffect.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 "GrMatrixConvolutionEffect.h"
 #include "gl/GrGLProcessor.h"
 #include "gl/GrGLSL.h"
 #include "gl/GrGLTexture.h"
 #include "gl/builders/GrGLProgramBuilder.h"

 class GrGLMatrixConvolutionEffect : public GrGLFragmentProcessor {
 public:
     GrGLMatrixConvolutionEffect(const GrProcessor&);
     virtual void emitCode(GrGLFPBuilder*,
                           const GrFragmentProcessor&,
                           const char* outputColor,
                           const char* inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) override;

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

     void setData(const GrGLProgramDataManager&, const GrProcessor&) override;

 private:
     typedef GrGLProgramDataManager::UniformHandle UniformHandle;
     SkISize                     fKernelSize;
     bool                        fConvolveAlpha;

     UniformHandle               fKernelUni;
     UniformHandle               fImageIncrementUni;
     UniformHandle               fKernelOffsetUni;
     UniformHandle               fGainUni;
     UniformHandle               fBiasUni;
     GrTextureDomain::GLDomain   fDomain;

     typedef GrGLFragmentProcessor INHERITED;
 };

 GrGLMatrixConvolutionEffect::GrGLMatrixConvolutionEffect(const GrProcessor& processor) {
     const GrMatrixConvolutionEffect& m = processor.cast<GrMatrixConvolutionEffect>();
     fKernelSize = m.kernelSize();
     fConvolveAlpha = m.convolveAlpha();
 }

 void GrGLMatrixConvolutionEffect::emitCode(GrGLFPBuilder* builder,
                                            const GrFragmentProcessor& fp,
                                            const char* outputColor,
                                            const char* inputColor,
                                            const TransformedCoordsArray& coords,
                                            const TextureSamplerArray& samplers) {
     const GrTextureDomain& domain = fp.cast<GrMatrixConvolutionEffect>().domain();
     fImageIncrementUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                              kVec2f_GrSLType, kDefault_GrSLPrecision,
                                              "ImageIncrement");
     fKernelUni = builder->addUniformArray(GrGLProgramBuilder::kFragment_Visibility,
                                           kFloat_GrSLType, kDefault_GrSLPrecision,
                                           "Kernel",
                                           fKernelSize.width() * fKernelSize.height());
     fKernelOffsetUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                            kVec2f_GrSLType, kDefault_GrSLPrecision, "KernelOffset");
     fGainUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                    kFloat_GrSLType, kDefault_GrSLPrecision, "Gain");
     fBiasUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                    kFloat_GrSLType, kDefault_GrSLPrecision, "Bias");

     const char* kernelOffset = builder->getUniformCStr(fKernelOffsetUni);
     const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
     const char* kernel = builder->getUniformCStr(fKernelUni);
     const char* gain = builder->getUniformCStr(fGainUni);
     const char* bias = builder->getUniformCStr(fBiasUni);
     int kWidth = fKernelSize.width();
     int kHeight = fKernelSize.height();

     GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
     SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 0);
     fsBuilder->codeAppend("vec4 sum = vec4(0, 0, 0, 0);");
     fsBuilder->codeAppendf("vec2 coord = %s - %s * %s;", coords2D.c_str(), kernelOffset,
                            imgInc);
     fsBuilder->codeAppend("vec4 c;");

     for (int y = 0; y < kHeight; y++) {
         for (int x = 0; x < kWidth; x++) {
             GrGLShaderBuilder::ShaderBlock block(fsBuilder);
             fsBuilder->codeAppendf("float k = %s[%d * %d + %d];", kernel, y, kWidth, x);
             SkString coord;
             coord.printf("coord + vec2(%d, %d) * %s", x, y, imgInc);
             fDomain.sampleTexture(fsBuilder, domain, "c", coord, samplers[0]);
             if (!fConvolveAlpha) {
                 fsBuilder->codeAppend("c.rgb /= c.a;");
                 fsBuilder->codeAppend("c.rgb = clamp(c.rgb, 0, 1);");
             }
             fsBuilder->codeAppend("sum += c * k;");
         }
     }
     if (fConvolveAlpha) {
         fsBuilder->codeAppendf("%s = sum * %s + %s;", outputColor, gain, bias);
         fsBuilder->codeAppendf("%s.rgb = clamp(%s.rgb, 0.0, %s.a);",
                                outputColor, outputColor, outputColor);
     } else {
         fDomain.sampleTexture(fsBuilder, domain, "c", coords2D, samplers[0]);
         fsBuilder->codeAppendf("%s.a = c.a;", outputColor);
         fsBuilder->codeAppendf("%s.rgb = sum.rgb * %s + %s;", outputColor, gain, bias);
         fsBuilder->codeAppendf("%s.rgb *= %s.a;", outputColor, outputColor);
     }

     SkString modulate;
     GrGLSLMulVarBy4f(&modulate, outputColor, inputColor);
     fsBuilder->codeAppend(modulate.c_str());
 }

 void GrGLMatrixConvolutionEffect::GenKey(const GrProcessor& processor,
                                          const GrGLCaps&, GrProcessorKeyBuilder* b) {
     const GrMatrixConvolutionEffect& m = processor.cast<GrMatrixConvolutionEffect>();
     SkASSERT(m.kernelSize().width() <= 0x7FFF && m.kernelSize().height() <= 0xFFFF);
     uint32_t key = m.kernelSize().width() << 16 | m.kernelSize().height();
     key |= m.convolveAlpha() ? 1 << 31 : 0;
     b->add32(key);
     b->add32(GrTextureDomain::GLDomain::DomainKey(m.domain()));
 }

 void GrGLMatrixConvolutionEffect::setData(const GrGLProgramDataManager& pdman,
                                           const GrProcessor& processor) {
     const GrMatrixConvolutionEffect& conv = processor.cast<GrMatrixConvolutionEffect>();
     GrTexture& texture = *conv.texture(0);
     // the code we generated was for a specific kernel size
     SkASSERT(conv.kernelSize() == fKernelSize);
     float imageIncrement[2];
     float ySign = texture.origin() == kTopLeft_GrSurfaceOrigin ? 1.0f : -1.0f;
     imageIncrement[0] = 1.0f / texture.width();
     imageIncrement[1] = ySign / texture.height();
     pdman.set2fv(fImageIncrementUni, 1, imageIncrement);
     pdman.set2fv(fKernelOffsetUni, 1, conv.kernelOffset());
     pdman.set1fv(fKernelUni, fKernelSize.width() * fKernelSize.height(), conv.kernel());
     pdman.set1f(fGainUni, conv.gain());
     pdman.set1f(fBiasUni, conv.bias());
     fDomain.setData(pdman, conv.domain(), texture.origin());
 }

 GrMatrixConvolutionEffect::GrMatrixConvolutionEffect(GrTexture* texture,
                                                      const SkIRect& bounds,
                                                      const SkISize& kernelSize,
                                                      const SkScalar* kernel,
                                                      SkScalar gain,
                                                      SkScalar bias,
                                                      const SkIPoint& kernelOffset,
                                                      GrTextureDomain::Mode tileMode,
                                                      bool convolveAlpha)
   : INHERITED(texture, GrCoordTransform::MakeDivByTextureWHMatrix(texture)),
     fKernelSize(kernelSize),
     fGain(SkScalarToFloat(gain)),
     fBias(SkScalarToFloat(bias) / 255.0f),
     fConvolveAlpha(convolveAlpha),
     fDomain(GrTextureDomain::MakeTexelDomainForMode(texture, bounds, tileMode), tileMode) {
     this->initClassID<GrMatrixConvolutionEffect>();
     for (int i = 0; i < kernelSize.width() * kernelSize.height(); i++) {
         fKernel[i] = SkScalarToFloat(kernel[i]);
     }
     fKernelOffset[0] = static_cast<float>(kernelOffset.x());
     fKernelOffset[1] = static_cast<float>(kernelOffset.y());
 }

 GrMatrixConvolutionEffect::~GrMatrixConvolutionEffect() {
 }

 void GrMatrixConvolutionEffect::getGLProcessorKey(const GrGLCaps& caps,
                                                   GrProcessorKeyBuilder* b) const {
     GrGLMatrixConvolutionEffect::GenKey(*this, caps, b);
 }

 GrGLFragmentProcessor* GrMatrixConvolutionEffect::createGLInstance() const  {
     return SkNEW_ARGS(GrGLMatrixConvolutionEffect, (*this));
 }

 bool GrMatrixConvolutionEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
     const GrMatrixConvolutionEffect& s = sBase.cast<GrMatrixConvolutionEffect>();
     return fKernelSize == s.kernelSize() &&
            !memcmp(fKernel, s.kernel(),
                    fKernelSize.width() * fKernelSize.height() * sizeof(float)) &&
            fGain == s.gain() &&
            fBias == s.bias() &&
            fKernelOffset == s.kernelOffset() &&
            fConvolveAlpha == s.convolveAlpha() &&
            fDomain == s.domain();
 }

 // Static function to create a 2D convolution
 GrFragmentProcessor*
 GrMatrixConvolutionEffect::CreateGaussian(GrTexture* texture,
                                           const SkIRect& bounds,
                                           const SkISize& kernelSize,
                                           SkScalar gain,
                                           SkScalar bias,
                                           const SkIPoint& kernelOffset,
                                           GrTextureDomain::Mode tileMode,
                                           bool convolveAlpha,
                                           SkScalar sigmaX,
                                           SkScalar sigmaY) {
     float kernel[MAX_KERNEL_SIZE];
     int width = kernelSize.width();
     int height = kernelSize.height();
     SkASSERT(width * height <= MAX_KERNEL_SIZE);
     float sum = 0.0f;
     float sigmaXDenom = 1.0f / (2.0f * SkScalarToFloat(SkScalarSquare(sigmaX)));
     float sigmaYDenom = 1.0f / (2.0f * SkScalarToFloat(SkScalarSquare(sigmaY)));
     int xRadius = width / 2;
     int yRadius = height / 2;
     for (int x = 0; x < width; x++) {
       float xTerm = static_cast<float>(x - xRadius);
       xTerm = xTerm * xTerm * sigmaXDenom;
       for (int y = 0; y < height; y++) {
         float yTerm = static_cast<float>(y - yRadius);
         float xyTerm = sk_float_exp(-(xTerm + yTerm * yTerm * sigmaYDenom));
         // Note that the constant term (1/(sqrt(2*pi*sigma^2)) of the Gaussian
        // is dropped here, since we renormalize the kernel below.
         kernel[y * width + x] = xyTerm;
         sum += xyTerm;
       }
     }
     // Normalize the kernel
     float scale = 1.0f / sum;
     for (int i = 0; i < width * height; ++i) {
         kernel[i] *= scale;
     }
     return SkNEW_ARGS(GrMatrixConvolutionEffect, (texture,
                                                   bounds,
                                                   kernelSize,
                                                   kernel,
                                                   gain,
                                                   bias,
                                                   kernelOffset,
                                                   tileMode,
                                                   convolveAlpha));
 }

 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrMatrixConvolutionEffect);

 GrFragmentProcessor* GrMatrixConvolutionEffect::TestCreate(SkRandom* random,
                                                            GrContext* context,
                                                            const GrDrawTargetCaps&,
                                                            GrTexture* textures[]) {
     int texIdx = random->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
                                       GrProcessorUnitTest::kAlphaTextureIdx;
     int width = random->nextRangeU(1, MAX_KERNEL_SIZE);
     int height = random->nextRangeU(1, MAX_KERNEL_SIZE / width);
     SkISize kernelSize = SkISize::Make(width, height);
     SkAutoTDeleteArray<SkScalar> kernel(new SkScalar[width * height]);
     for (int i = 0; i < width * height; i++) {
         kernel.get()[i] = random->nextSScalar1();
     }
     SkScalar gain = random->nextSScalar1();
     SkScalar bias = random->nextSScalar1();
     SkIPoint kernelOffset = SkIPoint::Make(random->nextRangeU(0, kernelSize.width()),
                                            random->nextRangeU(0, kernelSize.height()));
     SkIRect bounds = SkIRect::MakeXYWH(random->nextRangeU(0, textures[texIdx]->width()),
                                        random->nextRangeU(0, textures[texIdx]->height()),
                                        random->nextRangeU(0, textures[texIdx]->width()),
                                        random->nextRangeU(0, textures[texIdx]->height()));
     GrTextureDomain::Mode tileMode = static_cast<GrTextureDomain::Mode>(random->nextRangeU(0, 2));
     bool convolveAlpha = random->nextBool();
     return GrMatrixConvolutionEffect::Create(textures[texIdx],
                                              bounds,
                                              kernelSize,
                                              kernel.get(),
                                              gain,
                                              bias,
                                              kernelOffset,
                                              tileMode,
                                              convolveAlpha);
 }
	/*
	* 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 "GrMatrixConvolutionEffect.h"
	#include "gl/GrGLProcessor.h"
	#include "gl/GrGLSL.h"
	#include "gl/GrGLTexture.h"
	#include "gl/builders/GrGLProgramBuilder.h"

	class GrGLMatrixConvolutionEffect : public GrGLFragmentProcessor {
	public:
	GrGLMatrixConvolutionEffect(const GrProcessor&);
	virtual void emitCode(GrGLFPBuilder*,
	const GrFragmentProcessor&,
	const char* outputColor,
	const char* inputColor,
	const TransformedCoordsArray&,
	const TextureSamplerArray&) override;

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

	void setData(const GrGLProgramDataManager&, const GrProcessor&) override;

	private:
	typedef GrGLProgramDataManager::UniformHandle UniformHandle;
	SkISize fKernelSize;
	bool fConvolveAlpha;

	UniformHandle fKernelUni;
	UniformHandle fImageIncrementUni;
	UniformHandle fKernelOffsetUni;
	UniformHandle fGainUni;
	UniformHandle fBiasUni;
	GrTextureDomain::GLDomain fDomain;

	typedef GrGLFragmentProcessor INHERITED;
	};

	GrGLMatrixConvolutionEffect::GrGLMatrixConvolutionEffect(const GrProcessor& processor) {
	const GrMatrixConvolutionEffect& m = processor.cast<GrMatrixConvolutionEffect>();
	fKernelSize = m.kernelSize();
	fConvolveAlpha = m.convolveAlpha();
	}

	void GrGLMatrixConvolutionEffect::emitCode(GrGLFPBuilder* builder,
	const GrFragmentProcessor& fp,
	const char* outputColor,
	const char* inputColor,
	const TransformedCoordsArray& coords,
	const TextureSamplerArray& samplers) {
	const GrTextureDomain& domain = fp.cast<GrMatrixConvolutionEffect>().domain();
	fImageIncrementUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
	kVec2f_GrSLType, kDefault_GrSLPrecision,
	"ImageIncrement");
	fKernelUni = builder->addUniformArray(GrGLProgramBuilder::kFragment_Visibility,
	kFloat_GrSLType, kDefault_GrSLPrecision,
	"Kernel",
	fKernelSize.width() * fKernelSize.height());
	fKernelOffsetUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
	kVec2f_GrSLType, kDefault_GrSLPrecision, "KernelOffset");
	fGainUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
	kFloat_GrSLType, kDefault_GrSLPrecision, "Gain");
	fBiasUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
	kFloat_GrSLType, kDefault_GrSLPrecision, "Bias");

	const char* kernelOffset = builder->getUniformCStr(fKernelOffsetUni);
	const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
	const char* kernel = builder->getUniformCStr(fKernelUni);
	const char* gain = builder->getUniformCStr(fGainUni);
	const char* bias = builder->getUniformCStr(fBiasUni);
	int kWidth = fKernelSize.width();
	int kHeight = fKernelSize.height();

	GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
	SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 0);
	fsBuilder->codeAppend("vec4 sum = vec4(0, 0, 0, 0);");
	fsBuilder->codeAppendf("vec2 coord = %s - %s * %s;", coords2D.c_str(), kernelOffset,
	imgInc);
	fsBuilder->codeAppend("vec4 c;");

	for (int y = 0; y < kHeight; y++) {
	for (int x = 0; x < kWidth; x++) {
	GrGLShaderBuilder::ShaderBlock block(fsBuilder);
	fsBuilder->codeAppendf("float k = %s[%d * %d + %d];", kernel, y, kWidth, x);
	SkString coord;
	coord.printf("coord + vec2(%d, %d) * %s", x, y, imgInc);
	fDomain.sampleTexture(fsBuilder, domain, "c", coord, samplers[0]);
	if (!fConvolveAlpha) {
	fsBuilder->codeAppend("c.rgb /= c.a;");
	fsBuilder->codeAppend("c.rgb = clamp(c.rgb, 0, 1);");
	}
	fsBuilder->codeAppend("sum += c * k;");
	}
	}
	if (fConvolveAlpha) {
	fsBuilder->codeAppendf("%s = sum * %s + %s;", outputColor, gain, bias);
	fsBuilder->codeAppendf("%s.rgb = clamp(%s.rgb, 0.0, %s.a);",
	outputColor, outputColor, outputColor);
	} else {
	fDomain.sampleTexture(fsBuilder, domain, "c", coords2D, samplers[0]);
	fsBuilder->codeAppendf("%s.a = c.a;", outputColor);
	fsBuilder->codeAppendf("%s.rgb = sum.rgb * %s + %s;", outputColor, gain, bias);
	fsBuilder->codeAppendf("%s.rgb *= %s.a;", outputColor, outputColor);
	}

	SkString modulate;
	GrGLSLMulVarBy4f(&modulate, outputColor, inputColor);
	fsBuilder->codeAppend(modulate.c_str());
	}

	void GrGLMatrixConvolutionEffect::GenKey(const GrProcessor& processor,
	const GrGLCaps&, GrProcessorKeyBuilder* b) {
	const GrMatrixConvolutionEffect& m = processor.cast<GrMatrixConvolutionEffect>();
	SkASSERT(m.kernelSize().width() <= 0x7FFF && m.kernelSize().height() <= 0xFFFF);
	uint32_t key = m.kernelSize().width() << 16 \| m.kernelSize().height();
	key \|= m.convolveAlpha() ? 1 << 31 : 0;
	b->add32(key);
	b->add32(GrTextureDomain::GLDomain::DomainKey(m.domain()));
	}

	void GrGLMatrixConvolutionEffect::setData(const GrGLProgramDataManager& pdman,
	const GrProcessor& processor) {
	const GrMatrixConvolutionEffect& conv = processor.cast<GrMatrixConvolutionEffect>();
	GrTexture& texture = *conv.texture(0);
	// the code we generated was for a specific kernel size
	SkASSERT(conv.kernelSize() == fKernelSize);
	float imageIncrement[2];
	float ySign = texture.origin() == kTopLeft_GrSurfaceOrigin ? 1.0f : -1.0f;
	imageIncrement[0] = 1.0f / texture.width();
	imageIncrement[1] = ySign / texture.height();
	pdman.set2fv(fImageIncrementUni, 1, imageIncrement);
	pdman.set2fv(fKernelOffsetUni, 1, conv.kernelOffset());
	pdman.set1fv(fKernelUni, fKernelSize.width() * fKernelSize.height(), conv.kernel());
	pdman.set1f(fGainUni, conv.gain());
	pdman.set1f(fBiasUni, conv.bias());
	fDomain.setData(pdman, conv.domain(), texture.origin());
	}

	GrMatrixConvolutionEffect::GrMatrixConvolutionEffect(GrTexture* texture,
	const SkIRect& bounds,
	const SkISize& kernelSize,
	const SkScalar* kernel,
	SkScalar gain,
	SkScalar bias,
	const SkIPoint& kernelOffset,
	GrTextureDomain::Mode tileMode,
	bool convolveAlpha)
	: INHERITED(texture, GrCoordTransform::MakeDivByTextureWHMatrix(texture)),
	fKernelSize(kernelSize),
	fGain(SkScalarToFloat(gain)),
	fBias(SkScalarToFloat(bias) / 255.0f),
	fConvolveAlpha(convolveAlpha),
	fDomain(GrTextureDomain::MakeTexelDomainForMode(texture, bounds, tileMode), tileMode) {
	this->initClassID<GrMatrixConvolutionEffect>();
	for (int i = 0; i < kernelSize.width() * kernelSize.height(); i++) {
	fKernel[i] = SkScalarToFloat(kernel[i]);
	}
	fKernelOffset[0] = static_cast<float>(kernelOffset.x());
	fKernelOffset[1] = static_cast<float>(kernelOffset.y());
	}

	GrMatrixConvolutionEffect::~GrMatrixConvolutionEffect() {
	}

	void GrMatrixConvolutionEffect::getGLProcessorKey(const GrGLCaps& caps,
	GrProcessorKeyBuilder* b) const {
	GrGLMatrixConvolutionEffect::GenKey(*this, caps, b);
	}

	GrGLFragmentProcessor* GrMatrixConvolutionEffect::createGLInstance() const {
	return SkNEW_ARGS(GrGLMatrixConvolutionEffect, (*this));
	}

	bool GrMatrixConvolutionEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
	const GrMatrixConvolutionEffect& s = sBase.cast<GrMatrixConvolutionEffect>();
	return fKernelSize == s.kernelSize() &&
	!memcmp(fKernel, s.kernel(),
	fKernelSize.width() * fKernelSize.height() * sizeof(float)) &&
	fGain == s.gain() &&
	fBias == s.bias() &&
	fKernelOffset == s.kernelOffset() &&
	fConvolveAlpha == s.convolveAlpha() &&
	fDomain == s.domain();
	}

	// Static function to create a 2D convolution
	GrFragmentProcessor*
	GrMatrixConvolutionEffect::CreateGaussian(GrTexture* texture,
	const SkIRect& bounds,
	const SkISize& kernelSize,
	SkScalar gain,
	SkScalar bias,
	const SkIPoint& kernelOffset,
	GrTextureDomain::Mode tileMode,
	bool convolveAlpha,
	SkScalar sigmaX,
	SkScalar sigmaY) {
	float kernel[MAX_KERNEL_SIZE];
	int width = kernelSize.width();
	int height = kernelSize.height();
	SkASSERT(width * height <= MAX_KERNEL_SIZE);
	float sum = 0.0f;
	float sigmaXDenom = 1.0f / (2.0f * SkScalarToFloat(SkScalarSquare(sigmaX)));
	float sigmaYDenom = 1.0f / (2.0f * SkScalarToFloat(SkScalarSquare(sigmaY)));
	int xRadius = width / 2;
	int yRadius = height / 2;
	for (int x = 0; x < width; x++) {
	float xTerm = static_cast<float>(x - xRadius);
	xTerm = xTerm * xTerm * sigmaXDenom;
	for (int y = 0; y < height; y++) {
	float yTerm = static_cast<float>(y - yRadius);
	float xyTerm = sk_float_exp(-(xTerm + yTerm * yTerm * sigmaYDenom));
	// Note that the constant term (1/(sqrt(2pisigma^2)) of the Gaussian
	// is dropped here, since we renormalize the kernel below.
	kernel[y * width + x] = xyTerm;
	sum += xyTerm;
	}
	}
	// Normalize the kernel
	float scale = 1.0f / sum;
	for (int i = 0; i < width * height; ++i) {
	kernel[i] *= scale;
	}
	return SkNEW_ARGS(GrMatrixConvolutionEffect, (texture,
	bounds,
	kernelSize,
	kernel,
	gain,
	bias,
	kernelOffset,
	tileMode,
	convolveAlpha));
	}

	GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrMatrixConvolutionEffect);

	GrFragmentProcessor* GrMatrixConvolutionEffect::TestCreate(SkRandom* random,
	GrContext* context,
	const GrDrawTargetCaps&,
	GrTexture* textures[]) {
	int texIdx = random->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
	GrProcessorUnitTest::kAlphaTextureIdx;
	int width = random->nextRangeU(1, MAX_KERNEL_SIZE);
	int height = random->nextRangeU(1, MAX_KERNEL_SIZE / width);
	SkISize kernelSize = SkISize::Make(width, height);
	SkAutoTDeleteArray<SkScalar> kernel(new SkScalar[width * height]);
	for (int i = 0; i < width * height; i++) {
	kernel.get()[i] = random->nextSScalar1();
	}
	SkScalar gain = random->nextSScalar1();
	SkScalar bias = random->nextSScalar1();
	SkIPoint kernelOffset = SkIPoint::Make(random->nextRangeU(0, kernelSize.width()),
	random->nextRangeU(0, kernelSize.height()));
	SkIRect bounds = SkIRect::MakeXYWH(random->nextRangeU(0, textures[texIdx]->width()),
	random->nextRangeU(0, textures[texIdx]->height()),
	random->nextRangeU(0, textures[texIdx]->width()),
	random->nextRangeU(0, textures[texIdx]->height()));
	GrTextureDomain::Mode tileMode = static_cast<GrTextureDomain::Mode>(random->nextRangeU(0, 2));
	bool convolveAlpha = random->nextBool();
	return GrMatrixConvolutionEffect::Create(textures[texIdx],
	bounds,
	kernelSize,
	kernel.get(),
	gain,
	bias,
	kernelOffset,
	tileMode,
	convolveAlpha);
	}