src/gpu/effects/GrMatrixConvolutionEffect.cpp - skia.git - Git at Google


            
            /*

            
             * 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 "GrTexture.h"

            
            #include "GrTextureProxy.h"

            
            #include "glsl/GrGLSLFragmentProcessor.h"

            
            #include "glsl/GrGLSLFragmentShaderBuilder.h"

            
            #include "glsl/GrGLSLProgramDataManager.h"

            
            #include "glsl/GrGLSLUniformHandler.h"


            class GrGLMatrixConvolutionEffect : public GrGLSLFragmentProcessor {

            
            public:

            
                void emitCode(EmitArgs&) override;


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


            protected:

            
                void onSetData(const GrGLSLProgramDataManager&, const GrFragmentProcessor&) override;


            private:

            
                typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;


                UniformHandle               fKernelUni;

            
                UniformHandle               fImageIncrementUni;

            
                UniformHandle               fKernelOffsetUni;

            
                UniformHandle               fGainUni;

            
                UniformHandle               fBiasUni;

            
                GrTextureDomain::GLDomain   fDomain;


                typedef GrGLSLFragmentProcessor INHERITED;

            
            };


            void GrGLMatrixConvolutionEffect::emitCode(EmitArgs& args) {

            
                const GrMatrixConvolutionEffect& mce = args.fFp.cast<GrMatrixConvolutionEffect>();

            
                const GrTextureDomain& domain = mce.domain();


                int kWidth = mce.kernelSize().width();

            
                int kHeight = mce.kernelSize().height();


                int arrayCount = (kWidth * kHeight + 3) / 4;

            
                SkASSERT(4 * arrayCount >= kWidth * kHeight);


                GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;

            
                fImageIncrementUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType,

            
                                                                "ImageIncrement");

            
                fKernelUni = uniformHandler->addUniformArray(kFragment_GrShaderFlag, kHalf4_GrSLType,

            
                                                             "Kernel",

            
                                                             arrayCount);

            
                fKernelOffsetUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType,

            
                                                              "KernelOffset");

            
                fGainUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf_GrSLType, "Gain");

            
                fBiasUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf_GrSLType, "Bias");


                const char* kernelOffset = uniformHandler->getUniformCStr(fKernelOffsetUni);

            
                const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni);

            
                const char* kernel = uniformHandler->getUniformCStr(fKernelUni);

            
                const char* gain = uniformHandler->getUniformCStr(fGainUni);

            
                const char* bias = uniformHandler->getUniformCStr(fBiasUni);


                GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;

            
                SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);

            
                fragBuilder->codeAppend("half4 sum = half4(0, 0, 0, 0);");

            
                fragBuilder->codeAppendf("float2 coord = %s - %s * %s;", coords2D.c_str(), kernelOffset, imgInc);

            
                fragBuilder->codeAppend("half4 c;");


                const char* kVecSuffix[4] = { ".x", ".y", ".z", ".w" };

            
                for (int y = 0; y < kHeight; y++) {

            
                    for (int x = 0; x < kWidth; x++) {

            
                        GrGLSLShaderBuilder::ShaderBlock block(fragBuilder);

            
                        int offset = y*kWidth + x;


                        fragBuilder->codeAppendf("half k = %s[%d]%s;", kernel, offset / 4,

            
                                                 kVecSuffix[offset & 0x3]);

            
                        SkString coord;

            
                        coord.printf("coord + half2(%d, %d) * %s", x, y, imgInc);

            
                        fDomain.sampleTexture(fragBuilder,

            
                                              uniformHandler,

            
                                              args.fShaderCaps,

            
                                              domain,

            
                                              "c",

            
                                              coord,

            
                                              args.fTexSamplers[0]);

            
                        if (!mce.convolveAlpha()) {

            
                            fragBuilder->codeAppend("c.rgb /= c.a;");

            
                            fragBuilder->codeAppend("c.rgb = saturate(c.rgb);");

            
                        }

            
                        fragBuilder->codeAppend("sum += c * k;");

            
                    }

            
                }

            
                if (mce.convolveAlpha()) {

            
                    fragBuilder->codeAppendf("%s = sum * %s + %s;", args.fOutputColor, gain, bias);

            
                    fragBuilder->codeAppendf("%s.a = saturate(%s.a);", args.fOutputColor, args.fOutputColor);

            
                    fragBuilder->codeAppendf("%s.rgb = clamp(%s.rgb, 0.0, %s.a);",

            
                                             args.fOutputColor, args.fOutputColor, args.fOutputColor);

            
                } else {

            
                    fDomain.sampleTexture(fragBuilder,

            
                                          uniformHandler,

            
                                          args.fShaderCaps,

            
                                          domain,

            
                                          "c",

            
                                          coords2D,

            
                                          args.fTexSamplers[0]);

            
                    fragBuilder->codeAppendf("%s.a = c.a;", args.fOutputColor);

            
                    fragBuilder->codeAppendf("%s.rgb = saturate(sum.rgb * %s + %s);", args.fOutputColor, gain, bias);

            
                    fragBuilder->codeAppendf("%s.rgb *= %s.a;", args.fOutputColor, args.fOutputColor);

            
                }

            
                fragBuilder->codeAppendf("%s *= %s;\n", args.fOutputColor, args.fInputColor);

            
            }


            void GrGLMatrixConvolutionEffect::GenKey(const GrProcessor& processor,

            
                                                     const GrShaderCaps&, 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() ? 1U << 31 : 0;

            
                b->add32(key);

            
                b->add32(GrTextureDomain::GLDomain::DomainKey(m.domain()));

            
            }


            void GrGLMatrixConvolutionEffect::onSetData(const GrGLSLProgramDataManager& pdman,

            
                                                        const GrFragmentProcessor& processor) {

            
                const GrMatrixConvolutionEffect& conv = processor.cast<GrMatrixConvolutionEffect>();

            
                GrTextureProxy* proxy = conv.textureSampler(0).proxy();

            
                GrTexture* texture = proxy->peekTexture();


                float imageIncrement[2];

            
                float ySign = proxy->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());

            
                int kernelCount = conv.kernelSize().width() * conv.kernelSize().height();

            
                int arrayCount = (kernelCount + 3) / 4;

            
                SkASSERT(4 * arrayCount >= kernelCount);

            
                pdman.set4fv(fKernelUni, arrayCount, conv.kernel());

            
                pdman.set1f(fGainUni, conv.gain());

            
                pdman.set1f(fBiasUni, conv.bias());

            
                fDomain.setData(pdman, conv.domain(), proxy, conv.textureSampler(0).samplerState());

            
            }


            GrMatrixConvolutionEffect::GrMatrixConvolutionEffect(sk_sp<GrTextureProxy> srcProxy,

            
                                                                 const SkIRect& srcBounds,

            
                                                                 const SkISize& kernelSize,

            
                                                                 const SkScalar* kernel,

            
                                                                 SkScalar gain,

            
                                                                 SkScalar bias,

            
                                                                 const SkIPoint& kernelOffset,

            
                                                                 GrTextureDomain::Mode tileMode,

            
                                                                 bool convolveAlpha)

            
                    // To advertise either the modulation or opaqueness optimizations we'd have to examine the

            
                    // parameters.

            
                    : INHERITED(kGrMatrixConvolutionEffect_ClassID, kNone_OptimizationFlags)

            
                    , fCoordTransform(srcProxy.get())

            
                    , fDomain(srcProxy.get(), GrTextureDomain::MakeTexelDomain(srcBounds, tileMode),

            
                              tileMode, tileMode)

            
                    , fTextureSampler(std::move(srcProxy))

            
                    , fKernelSize(kernelSize)

            
                    , fGain(SkScalarToFloat(gain))

            
                    , fBias(SkScalarToFloat(bias) / 255.0f)

            
                    , fConvolveAlpha(convolveAlpha) {

            
                this->addCoordTransform(&fCoordTransform);

            
                this->setTextureSamplerCnt(1);

            
                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(const GrMatrixConvolutionEffect& that)

            
                    : INHERITED(kGrMatrixConvolutionEffect_ClassID, kNone_OptimizationFlags)

            
                    , fCoordTransform(that.fCoordTransform)

            
                    , fDomain(that.fDomain)

            
                    , fTextureSampler(that.fTextureSampler)

            
                    , fKernelSize(that.fKernelSize)

            
                    , fGain(that.fGain)

            
                    , fBias(that.fBias)

            
                    , fConvolveAlpha(that.fConvolveAlpha) {

            
                this->addCoordTransform(&fCoordTransform);

            
                this->setTextureSamplerCnt(1);

            
                memcpy(fKernel, that.fKernel, sizeof(float) * fKernelSize.width() * fKernelSize.height());

            
                memcpy(fKernelOffset, that.fKernelOffset, sizeof(fKernelOffset));

            
            }


            std::unique_ptr<GrFragmentProcessor> GrMatrixConvolutionEffect::clone() const {

            
                return std::unique_ptr<GrFragmentProcessor>(new GrMatrixConvolutionEffect(*this));

            
            }


            void GrMatrixConvolutionEffect::onGetGLSLProcessorKey(const GrShaderCaps& caps,

            
                                                                  GrProcessorKeyBuilder* b) const {

            
                GrGLMatrixConvolutionEffect::GenKey(*this, caps, b);

            
            }


            GrGLSLFragmentProcessor* GrMatrixConvolutionEffect::onCreateGLSLInstance() const  {

            
                return new GrGLMatrixConvolutionEffect;

            
            }


            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() &&

            
                       !memcmp(fKernelOffset, s.kernelOffset(), sizeof(fKernelOffset)) &&

            
                       fConvolveAlpha == s.convolveAlpha() &&

            
                       fDomain == s.domain();

            
            }


            static void fill_in_1D_gaussian_kernel_with_stride(float* kernel, int size, int stride,

            
                                                               float twoSigmaSqrd) {

            
                SkASSERT(!SkScalarNearlyZero(twoSigmaSqrd, SK_ScalarNearlyZero));


                const float sigmaDenom = 1.0f / twoSigmaSqrd;

            
                const int radius = size / 2;


                float sum = 0.0f;

            
                for (int i = 0; i < size; ++i) {

            
                    float term = static_cast<float>(i - radius);

            
                    // Note that the constant term (1/(sqrt(2*pi*sigma^2)) of the Gaussian

            
                    // is dropped here, since we renormalize the kernel below.

            
                    kernel[i * stride] = sk_float_exp(-term * term * sigmaDenom);

            
                    sum += kernel[i * stride];

            
                }

            
                // Normalize the kernel

            
                float scale = 1.0f / sum;

            
                for (int i = 0; i < size; ++i) {

            
                    kernel[i * stride] *= scale;

            
                }

            
            }


            static void fill_in_2D_gaussian_kernel(float* kernel, int width, int height,

            
                                                   SkScalar sigmaX, SkScalar sigmaY) {

            
                SkASSERT(width * height <= MAX_KERNEL_SIZE);

            
                const float twoSigmaSqrdX = 2.0f * SkScalarToFloat(SkScalarSquare(sigmaX));

            
                const float twoSigmaSqrdY = 2.0f * SkScalarToFloat(SkScalarSquare(sigmaY));


                // TODO: in all of these degenerate cases we're uploading (and using) a whole lot of zeros.

            
                if (SkScalarNearlyZero(twoSigmaSqrdX, SK_ScalarNearlyZero) ||

            
                    SkScalarNearlyZero(twoSigmaSqrdY, SK_ScalarNearlyZero)) {

            
                    // In this case the 2D Gaussian degenerates to a 1D Gaussian (in X or Y) or a point

            
                    SkASSERT(3 == width || 3 == height);

            
                    memset(kernel, 0, width*height*sizeof(float));


                    if (SkScalarNearlyZero(twoSigmaSqrdX, SK_ScalarNearlyZero) &&

            
                        SkScalarNearlyZero(twoSigmaSqrdY, SK_ScalarNearlyZero)) {

            
                        // A point

            
                        SkASSERT(3 == width && 3 == height);

            
                        kernel[4] = 1.0f;

            
                    } else if (SkScalarNearlyZero(twoSigmaSqrdX, SK_ScalarNearlyZero)) {

            
                        // A 1D Gaussian in Y

            
                        SkASSERT(3 == width);

            
                        // Down the middle column of the kernel with a stride of width

            
                        fill_in_1D_gaussian_kernel_with_stride(&kernel[1], height, width, twoSigmaSqrdY);

            
                    } else {

            
                        // A 1D Gaussian in X

            
                        SkASSERT(SkScalarNearlyZero(twoSigmaSqrdY, SK_ScalarNearlyZero));

            
                        SkASSERT(3 == height);

            
                        // Down the middle row of the kernel with a stride of 1

            
                        fill_in_1D_gaussian_kernel_with_stride(&kernel[width], width, 1, twoSigmaSqrdX);

            
                    }

            
                    return;

            
                }


                const float sigmaXDenom = 1.0f / twoSigmaSqrdX;

            
                const float sigmaYDenom = 1.0f / twoSigmaSqrdY;

            
                const int xRadius = width / 2;

            
                const int yRadius = height / 2;


                float sum = 0.0f;

            
                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;

            
                }

            
            }


            // Static function to create a 2D convolution

            
            std::unique_ptr<GrFragmentProcessor> GrMatrixConvolutionEffect::MakeGaussian(

            
                    sk_sp<GrTextureProxy> srcProxy,

            
                    const SkIRect& srcBounds,

            
                    const SkISize& kernelSize,

            
                    SkScalar gain,

            
                    SkScalar bias,

            
                    const SkIPoint& kernelOffset,

            
                    GrTextureDomain::Mode tileMode,

            
                    bool convolveAlpha,

            
                    SkScalar sigmaX,

            
                    SkScalar sigmaY) {

            
                float kernel[MAX_KERNEL_SIZE];


                fill_in_2D_gaussian_kernel(kernel, kernelSize.width(), kernelSize.height(), sigmaX, sigmaY);


                return std::unique_ptr<GrFragmentProcessor>(

            
                        new GrMatrixConvolutionEffect(std::move(srcProxy), srcBounds, kernelSize, kernel,

            
                                                      gain, bias, kernelOffset, tileMode, convolveAlpha));

            
            }


            GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrMatrixConvolutionEffect);


            #if GR_TEST_UTILS

            
            std::unique_ptr<GrFragmentProcessor> GrMatrixConvolutionEffect::TestCreate(GrProcessorTestData* d) {

            
                int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx

            
                                                    : GrProcessorUnitTest::kAlphaTextureIdx;

            
                sk_sp<GrTextureProxy> proxy = d->textureProxy(texIdx);


                int width = d->fRandom->nextRangeU(1, MAX_KERNEL_SIZE);

            
                int height = d->fRandom->nextRangeU(1, MAX_KERNEL_SIZE / width);

            
                SkISize kernelSize = SkISize::Make(width, height);

            
                std::unique_ptr<SkScalar[]> kernel(new SkScalar[width * height]);

            
                for (int i = 0; i < width * height; i++) {

            
                    kernel.get()[i] = d->fRandom->nextSScalar1();

            
                }

            
                SkScalar gain = d->fRandom->nextSScalar1();

            
                SkScalar bias = d->fRandom->nextSScalar1();

            
                SkIPoint kernelOffset = SkIPoint::Make(d->fRandom->nextRangeU(0, kernelSize.width()),

            
                                                       d->fRandom->nextRangeU(0, kernelSize.height()));

            
                SkIRect bounds = SkIRect::MakeXYWH(d->fRandom->nextRangeU(0, proxy->width()),

            
                                                   d->fRandom->nextRangeU(0, proxy->height()),

            
                                                   d->fRandom->nextRangeU(0, proxy->width()),

            
                                                   d->fRandom->nextRangeU(0, proxy->height()));

            
                GrTextureDomain::Mode tileMode =

            
                        static_cast<GrTextureDomain::Mode>(d->fRandom->nextRangeU(0, 2));

            
                bool convolveAlpha = d->fRandom->nextBool();

            
                return GrMatrixConvolutionEffect::Make(std::move(proxy),

            
                                                       bounds,

            
                                                       kernelSize,

            
                                                       kernel.get(),

            
                                                       gain,

            
                                                       bias,

            
                                                       kernelOffset,

            
                                                       tileMode,

            
                                                       convolveAlpha);

            
            }

            
            #endif
	/*
	* 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 "GrTexture.h"
	#include "GrTextureProxy.h"
	#include "glsl/GrGLSLFragmentProcessor.h"
	#include "glsl/GrGLSLFragmentShaderBuilder.h"
	#include "glsl/GrGLSLProgramDataManager.h"
	#include "glsl/GrGLSLUniformHandler.h"

	class GrGLMatrixConvolutionEffect : public GrGLSLFragmentProcessor {
	public:
	void emitCode(EmitArgs&) override;

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

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

	private:
	typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;

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

	typedef GrGLSLFragmentProcessor INHERITED;
	};

	void GrGLMatrixConvolutionEffect::emitCode(EmitArgs& args) {
	const GrMatrixConvolutionEffect& mce = args.fFp.cast<GrMatrixConvolutionEffect>();
	const GrTextureDomain& domain = mce.domain();

	int kWidth = mce.kernelSize().width();
	int kHeight = mce.kernelSize().height();

	int arrayCount = (kWidth * kHeight + 3) / 4;
	SkASSERT(4 * arrayCount >= kWidth * kHeight);

	GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
	fImageIncrementUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType,
	"ImageIncrement");
	fKernelUni = uniformHandler->addUniformArray(kFragment_GrShaderFlag, kHalf4_GrSLType,
	"Kernel",
	arrayCount);
	fKernelOffsetUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType,
	"KernelOffset");
	fGainUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf_GrSLType, "Gain");
	fBiasUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf_GrSLType, "Bias");

	const char* kernelOffset = uniformHandler->getUniformCStr(fKernelOffsetUni);
	const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni);
	const char* kernel = uniformHandler->getUniformCStr(fKernelUni);
	const char* gain = uniformHandler->getUniformCStr(fGainUni);
	const char* bias = uniformHandler->getUniformCStr(fBiasUni);

	GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
	SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
	fragBuilder->codeAppend("half4 sum = half4(0, 0, 0, 0);");
	fragBuilder->codeAppendf("float2 coord = %s - %s * %s;", coords2D.c_str(), kernelOffset, imgInc);
	fragBuilder->codeAppend("half4 c;");

	const char* kVecSuffix[4] = { ".x", ".y", ".z", ".w" };
	for (int y = 0; y < kHeight; y++) {
	for (int x = 0; x < kWidth; x++) {
	GrGLSLShaderBuilder::ShaderBlock block(fragBuilder);
	int offset = y*kWidth + x;

	fragBuilder->codeAppendf("half k = %s[%d]%s;", kernel, offset / 4,
	kVecSuffix[offset & 0x3]);
	SkString coord;
	coord.printf("coord + half2(%d, %d) * %s", x, y, imgInc);
	fDomain.sampleTexture(fragBuilder,
	uniformHandler,
	args.fShaderCaps,
	domain,
	"c",
	coord,
	args.fTexSamplers[0]);
	if (!mce.convolveAlpha()) {
	fragBuilder->codeAppend("c.rgb /= c.a;");
	fragBuilder->codeAppend("c.rgb = saturate(c.rgb);");
	}
	fragBuilder->codeAppend("sum += c * k;");
	}
	}
	if (mce.convolveAlpha()) {
	fragBuilder->codeAppendf("%s = sum * %s + %s;", args.fOutputColor, gain, bias);
	fragBuilder->codeAppendf("%s.a = saturate(%s.a);", args.fOutputColor, args.fOutputColor);
	fragBuilder->codeAppendf("%s.rgb = clamp(%s.rgb, 0.0, %s.a);",
	args.fOutputColor, args.fOutputColor, args.fOutputColor);
	} else {
	fDomain.sampleTexture(fragBuilder,
	uniformHandler,
	args.fShaderCaps,
	domain,
	"c",
	coords2D,
	args.fTexSamplers[0]);
	fragBuilder->codeAppendf("%s.a = c.a;", args.fOutputColor);
	fragBuilder->codeAppendf("%s.rgb = saturate(sum.rgb * %s + %s);", args.fOutputColor, gain, bias);
	fragBuilder->codeAppendf("%s.rgb *= %s.a;", args.fOutputColor, args.fOutputColor);
	}
	fragBuilder->codeAppendf("%s *= %s;\n", args.fOutputColor, args.fInputColor);
	}

	void GrGLMatrixConvolutionEffect::GenKey(const GrProcessor& processor,
	const GrShaderCaps&, 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() ? 1U << 31 : 0;
	b->add32(key);
	b->add32(GrTextureDomain::GLDomain::DomainKey(m.domain()));
	}

	void GrGLMatrixConvolutionEffect::onSetData(const GrGLSLProgramDataManager& pdman,
	const GrFragmentProcessor& processor) {
	const GrMatrixConvolutionEffect& conv = processor.cast<GrMatrixConvolutionEffect>();
	GrTextureProxy* proxy = conv.textureSampler(0).proxy();
	GrTexture* texture = proxy->peekTexture();

	float imageIncrement[2];
	float ySign = proxy->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());
	int kernelCount = conv.kernelSize().width() * conv.kernelSize().height();
	int arrayCount = (kernelCount + 3) / 4;
	SkASSERT(4 * arrayCount >= kernelCount);
	pdman.set4fv(fKernelUni, arrayCount, conv.kernel());
	pdman.set1f(fGainUni, conv.gain());
	pdman.set1f(fBiasUni, conv.bias());
	fDomain.setData(pdman, conv.domain(), proxy, conv.textureSampler(0).samplerState());
	}

	GrMatrixConvolutionEffect::GrMatrixConvolutionEffect(sk_sp<GrTextureProxy> srcProxy,
	const SkIRect& srcBounds,
	const SkISize& kernelSize,
	const SkScalar* kernel,
	SkScalar gain,
	SkScalar bias,
	const SkIPoint& kernelOffset,
	GrTextureDomain::Mode tileMode,
	bool convolveAlpha)
	// To advertise either the modulation or opaqueness optimizations we'd have to examine the
	// parameters.
	: INHERITED(kGrMatrixConvolutionEffect_ClassID, kNone_OptimizationFlags)
	, fCoordTransform(srcProxy.get())
	, fDomain(srcProxy.get(), GrTextureDomain::MakeTexelDomain(srcBounds, tileMode),
	tileMode, tileMode)
	, fTextureSampler(std::move(srcProxy))
	, fKernelSize(kernelSize)
	, fGain(SkScalarToFloat(gain))
	, fBias(SkScalarToFloat(bias) / 255.0f)
	, fConvolveAlpha(convolveAlpha) {
	this->addCoordTransform(&fCoordTransform);
	this->setTextureSamplerCnt(1);
	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(const GrMatrixConvolutionEffect& that)
	: INHERITED(kGrMatrixConvolutionEffect_ClassID, kNone_OptimizationFlags)
	, fCoordTransform(that.fCoordTransform)
	, fDomain(that.fDomain)
	, fTextureSampler(that.fTextureSampler)
	, fKernelSize(that.fKernelSize)
	, fGain(that.fGain)
	, fBias(that.fBias)
	, fConvolveAlpha(that.fConvolveAlpha) {
	this->addCoordTransform(&fCoordTransform);
	this->setTextureSamplerCnt(1);
	memcpy(fKernel, that.fKernel, sizeof(float) * fKernelSize.width() * fKernelSize.height());
	memcpy(fKernelOffset, that.fKernelOffset, sizeof(fKernelOffset));
	}

	std::unique_ptr<GrFragmentProcessor> GrMatrixConvolutionEffect::clone() const {
	return std::unique_ptr<GrFragmentProcessor>(new GrMatrixConvolutionEffect(*this));
	}

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

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

	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() &&
	!memcmp(fKernelOffset, s.kernelOffset(), sizeof(fKernelOffset)) &&
	fConvolveAlpha == s.convolveAlpha() &&
	fDomain == s.domain();
	}

	static void fill_in_1D_gaussian_kernel_with_stride(float* kernel, int size, int stride,
	float twoSigmaSqrd) {
	SkASSERT(!SkScalarNearlyZero(twoSigmaSqrd, SK_ScalarNearlyZero));

	const float sigmaDenom = 1.0f / twoSigmaSqrd;
	const int radius = size / 2;

	float sum = 0.0f;
	for (int i = 0; i < size; ++i) {
	float term = static_cast<float>(i - radius);
	// Note that the constant term (1/(sqrt(2pisigma^2)) of the Gaussian
	// is dropped here, since we renormalize the kernel below.
	kernel[i * stride] = sk_float_exp(-term * term * sigmaDenom);
	sum += kernel[i * stride];
	}
	// Normalize the kernel
	float scale = 1.0f / sum;
	for (int i = 0; i < size; ++i) {
	kernel[i * stride] *= scale;
	}
	}

	static void fill_in_2D_gaussian_kernel(float* kernel, int width, int height,
	SkScalar sigmaX, SkScalar sigmaY) {
	SkASSERT(width * height <= MAX_KERNEL_SIZE);
	const float twoSigmaSqrdX = 2.0f * SkScalarToFloat(SkScalarSquare(sigmaX));
	const float twoSigmaSqrdY = 2.0f * SkScalarToFloat(SkScalarSquare(sigmaY));

	// TODO: in all of these degenerate cases we're uploading (and using) a whole lot of zeros.
	if (SkScalarNearlyZero(twoSigmaSqrdX, SK_ScalarNearlyZero) \|\|
	SkScalarNearlyZero(twoSigmaSqrdY, SK_ScalarNearlyZero)) {
	// In this case the 2D Gaussian degenerates to a 1D Gaussian (in X or Y) or a point
	SkASSERT(3 == width \|\| 3 == height);
	memset(kernel, 0, widthheightsizeof(float));

	if (SkScalarNearlyZero(twoSigmaSqrdX, SK_ScalarNearlyZero) &&
	SkScalarNearlyZero(twoSigmaSqrdY, SK_ScalarNearlyZero)) {
	// A point
	SkASSERT(3 == width && 3 == height);
	kernel[4] = 1.0f;
	} else if (SkScalarNearlyZero(twoSigmaSqrdX, SK_ScalarNearlyZero)) {
	// A 1D Gaussian in Y
	SkASSERT(3 == width);
	// Down the middle column of the kernel with a stride of width
	fill_in_1D_gaussian_kernel_with_stride(&kernel[1], height, width, twoSigmaSqrdY);
	} else {
	// A 1D Gaussian in X
	SkASSERT(SkScalarNearlyZero(twoSigmaSqrdY, SK_ScalarNearlyZero));
	SkASSERT(3 == height);
	// Down the middle row of the kernel with a stride of 1
	fill_in_1D_gaussian_kernel_with_stride(&kernel[width], width, 1, twoSigmaSqrdX);
	}
	return;
	}

	const float sigmaXDenom = 1.0f / twoSigmaSqrdX;
	const float sigmaYDenom = 1.0f / twoSigmaSqrdY;
	const int xRadius = width / 2;
	const int yRadius = height / 2;

	float sum = 0.0f;
	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;
	}
	}

	// Static function to create a 2D convolution
	std::unique_ptr<GrFragmentProcessor> GrMatrixConvolutionEffect::MakeGaussian(
	sk_sp<GrTextureProxy> srcProxy,
	const SkIRect& srcBounds,
	const SkISize& kernelSize,
	SkScalar gain,
	SkScalar bias,
	const SkIPoint& kernelOffset,
	GrTextureDomain::Mode tileMode,
	bool convolveAlpha,
	SkScalar sigmaX,
	SkScalar sigmaY) {
	float kernel[MAX_KERNEL_SIZE];

	fill_in_2D_gaussian_kernel(kernel, kernelSize.width(), kernelSize.height(), sigmaX, sigmaY);

	return std::unique_ptr<GrFragmentProcessor>(
	new GrMatrixConvolutionEffect(std::move(srcProxy), srcBounds, kernelSize, kernel,
	gain, bias, kernelOffset, tileMode, convolveAlpha));
	}

	GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrMatrixConvolutionEffect);

	#if GR_TEST_UTILS
	std::unique_ptr<GrFragmentProcessor> GrMatrixConvolutionEffect::TestCreate(GrProcessorTestData* d) {
	int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx
	: GrProcessorUnitTest::kAlphaTextureIdx;
	sk_sp<GrTextureProxy> proxy = d->textureProxy(texIdx);

	int width = d->fRandom->nextRangeU(1, MAX_KERNEL_SIZE);
	int height = d->fRandom->nextRangeU(1, MAX_KERNEL_SIZE / width);
	SkISize kernelSize = SkISize::Make(width, height);
	std::unique_ptr<SkScalar[]> kernel(new SkScalar[width * height]);
	for (int i = 0; i < width * height; i++) {
	kernel.get()[i] = d->fRandom->nextSScalar1();
	}
	SkScalar gain = d->fRandom->nextSScalar1();
	SkScalar bias = d->fRandom->nextSScalar1();
	SkIPoint kernelOffset = SkIPoint::Make(d->fRandom->nextRangeU(0, kernelSize.width()),
	d->fRandom->nextRangeU(0, kernelSize.height()));
	SkIRect bounds = SkIRect::MakeXYWH(d->fRandom->nextRangeU(0, proxy->width()),
	d->fRandom->nextRangeU(0, proxy->height()),
	d->fRandom->nextRangeU(0, proxy->width()),
	d->fRandom->nextRangeU(0, proxy->height()));
	GrTextureDomain::Mode tileMode =
	static_cast<GrTextureDomain::Mode>(d->fRandom->nextRangeU(0, 2));
	bool convolveAlpha = d->fRandom->nextBool();
	return GrMatrixConvolutionEffect::Make(std::move(proxy),
	bounds,
	kernelSize,
	kernel.get(),
	gain,
	bias,
	kernelOffset,
	tileMode,
	convolveAlpha);
	}
	#endif