src/effects/SkColorMatrixFilter.cpp - skia.git - Git at Google

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkColorMatrixFilter.h"
 #include "SkColorMatrix.h"
 #include "SkColorPriv.h"
 #include "SkNx.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkUnPreMultiply.h"
 #include "SkString.h"

 #define SK_PMORDER_INDEX_A  (SK_A32_SHIFT / 8)
 #define SK_PMORDER_INDEX_R  (SK_R32_SHIFT / 8)
 #define SK_PMORDER_INDEX_G  (SK_G32_SHIFT / 8)
 #define SK_PMORDER_INDEX_B  (SK_B32_SHIFT / 8)

 static void transpose_to_pmorder(float dst[20], const float src[20]) {
     const float* srcR = src + 0;
     const float* srcG = src + 5;
     const float* srcB = src + 10;
     const float* srcA = src + 15;

     for (int i = 0; i < 20; i += 4) {
         dst[i + SK_PMORDER_INDEX_A] = *srcA++;
         dst[i + SK_PMORDER_INDEX_R] = *srcR++;
         dst[i + SK_PMORDER_INDEX_G] = *srcG++;
         dst[i + SK_PMORDER_INDEX_B] = *srcB++;
     }
 }

 // src is [20] but some compilers won't accept __restrict__ on anything
 // but an raw pointer or reference
 void SkColorMatrixFilter::initState(const SkScalar* SK_RESTRICT src) {
     transpose_to_pmorder(fTranspose, src);

     const float* array = fMatrix.fMat;

     // check if we have to munge Alpha
     bool changesAlpha = (array[15] || array[16] || array[17] || (array[18] - 1) || array[19]);
     bool usesAlpha = (array[3] || array[8] || array[13]);

     if (changesAlpha || usesAlpha) {
         fFlags = changesAlpha ? 0 : SkColorFilter::kAlphaUnchanged_Flag;
     } else {
         fFlags = SkColorFilter::kAlphaUnchanged_Flag;
     }
 }

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

 SkColorMatrixFilter::SkColorMatrixFilter(const SkColorMatrix& cm) : fMatrix(cm) {
     this->initState(cm.fMat);
 }

 SkColorMatrixFilter::SkColorMatrixFilter(const SkScalar array[20]) {
     memcpy(fMatrix.fMat, array, 20 * sizeof(SkScalar));
     this->initState(array);
 }

 uint32_t SkColorMatrixFilter::getFlags() const {
     return this->INHERITED::getFlags() | fFlags;
 }

 static Sk4f scale_rgb(float scale) {
     static_assert(SK_A32_SHIFT == 24, "Alpha is lane 3");
     return Sk4f(scale, scale, scale, 1);
 }

 static Sk4f premul(const Sk4f& x) {
     return x * scale_rgb(x.kth<SK_A32_SHIFT/8>());
 }

 static Sk4f unpremul(const Sk4f& x) {
     return x * scale_rgb(1 / x.kth<SK_A32_SHIFT/8>());  // TODO: fast/approx invert?
 }

 static Sk4f clamp_0_1(const Sk4f& x) {
     return Sk4f::Max(Sk4f::Min(x, Sk4f(1)), Sk4f(0));
 }

 static SkPMColor round(const Sk4f& x) {
     SkPMColor c;
     SkNx_cast<uint8_t>(x * Sk4f(255) + Sk4f(0.5f)).store((uint8_t*)&c);
     return c;
 }

 void SkColorMatrixFilter::filterSpan(const SkPMColor src[], int count, SkPMColor dst[]) const {
     // c0-c3 are already in [0,1].
     const Sk4f c0 = Sk4f::Load(fTranspose + 0);
     const Sk4f c1 = Sk4f::Load(fTranspose + 4);
     const Sk4f c2 = Sk4f::Load(fTranspose + 8);
     const Sk4f c3 = Sk4f::Load(fTranspose + 12);
     // c4 (the translate vector) is in [0, 255].  Bring it back to [0,1].
     const Sk4f c4 = Sk4f::Load(fTranspose + 16)*Sk4f(1.0f/255);

     // todo: we could cache this in the constructor...
     SkPMColor matrix_translate_pmcolor = round(premul(clamp_0_1(c4)));

     for (int i = 0; i < count; i++) {
         const SkPMColor src_c = src[i];
         if (0 == src_c) {
             dst[i] = matrix_translate_pmcolor;
             continue;
         }

         Sk4f srcf = SkNx_cast<float>(Sk4b::Load((const uint8_t*)&src_c)) * Sk4f(1.0f/255);

         if (0xFF != SkGetPackedA32(src_c)) {
             srcf = unpremul(srcf);
         }

         Sk4f r4 = SkNx_dup<SK_R32_SHIFT/8>(srcf);
         Sk4f g4 = SkNx_dup<SK_G32_SHIFT/8>(srcf);
         Sk4f b4 = SkNx_dup<SK_B32_SHIFT/8>(srcf);
         Sk4f a4 = SkNx_dup<SK_A32_SHIFT/8>(srcf);

         // apply matrix
         Sk4f dst4 = c0 * r4 + c1 * g4 + c2 * b4 + c3 * a4 + c4;

         // clamp, re-premul, and write
         dst[i] = round(premul(clamp_0_1(dst4)));
     }
 }

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

 void SkColorMatrixFilter::flatten(SkWriteBuffer& buffer) const {
     SkASSERT(sizeof(fMatrix.fMat)/sizeof(SkScalar) == 20);
     buffer.writeScalarArray(fMatrix.fMat, 20);
 }

 SkFlattenable* SkColorMatrixFilter::CreateProc(SkReadBuffer& buffer) {
     SkColorMatrix matrix;
     if (buffer.readScalarArray(matrix.fMat, 20)) {
         return Create(matrix);
     }
     return nullptr;
 }

 bool SkColorMatrixFilter::asColorMatrix(SkScalar matrix[20]) const {
     if (matrix) {
         memcpy(matrix, fMatrix.fMat, 20 * sizeof(SkScalar));
     }
     return true;
 }

 SkColorFilter* SkColorMatrixFilter::newComposed(const SkColorFilter* innerFilter) const {
     SkScalar innerMatrix[20];
     if (innerFilter->asColorMatrix(innerMatrix) && !SkColorMatrix::NeedsClamping(innerMatrix)) {
         SkScalar concat[20];
         SkColorMatrix::SetConcat(concat, fMatrix.fMat, innerMatrix);
         return SkColorMatrixFilter::Create(concat);
     }
     return nullptr;
 }

 #if SK_SUPPORT_GPU
 #include "GrFragmentProcessor.h"
 #include "GrInvariantOutput.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProgramDataManager.h"
 #include "glsl/GrGLSLUniformHandler.h"

 class ColorMatrixEffect : public GrFragmentProcessor {
 public:
     static const GrFragmentProcessor* Create(const SkColorMatrix& matrix) {
         return new ColorMatrixEffect(matrix);
     }

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

     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

     class GLSLProcessor : public GrGLSLFragmentProcessor {
     public:
         // this class always generates the same code.
         static void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder* b) {}

         GLSLProcessor(const GrProcessor&) {}

         virtual void emitCode(EmitArgs& args) override {
             GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
             fMatrixHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
                                                        kMat44f_GrSLType, kDefault_GrSLPrecision,
                                                        "ColorMatrix");
             fVectorHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
                                                        kVec4f_GrSLType, kDefault_GrSLPrecision,
                                                        "ColorMatrixVector");

             if (nullptr == args.fInputColor) {
                 // could optimize this case, but we aren't for now.
                 args.fInputColor = "vec4(1)";
             }
             GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
             // The max() is to guard against 0 / 0 during unpremul when the incoming color is
             // transparent black.
             fragBuilder->codeAppendf("\tfloat nonZeroAlpha = max(%s.a, 0.00001);\n",
                                      args.fInputColor);
             fragBuilder->codeAppendf("\t%s = %s * vec4(%s.rgb / nonZeroAlpha, nonZeroAlpha) + %s;\n",
                                      args.fOutputColor,
                                      uniformHandler->getUniformCStr(fMatrixHandle),
                                      args.fInputColor,
                                      uniformHandler->getUniformCStr(fVectorHandle));
             fragBuilder->codeAppendf("\t%s = clamp(%s, 0.0, 1.0);\n",
                                      args.fOutputColor, args.fOutputColor);
             fragBuilder->codeAppendf("\t%s.rgb *= %s.a;\n", args.fOutputColor, args.fOutputColor);
         }

     protected:
         virtual void onSetData(const GrGLSLProgramDataManager& uniManager,
                                const GrProcessor& proc) override {
             const ColorMatrixEffect& cme = proc.cast<ColorMatrixEffect>();
             const float* m = cme.fMatrix.fMat;
             // The GL matrix is transposed from SkColorMatrix.
             float mt[]  = {
                 m[0], m[5], m[10], m[15],
                 m[1], m[6], m[11], m[16],
                 m[2], m[7], m[12], m[17],
                 m[3], m[8], m[13], m[18],
             };
             static const float kScale = 1.0f / 255.0f;
             float vec[] = {
                 m[4] * kScale, m[9] * kScale, m[14] * kScale, m[19] * kScale,
             };
             uniManager.setMatrix4fv(fMatrixHandle, 1, mt);
             uniManager.set4fv(fVectorHandle, 1, vec);
         }

     private:
         GrGLSLProgramDataManager::UniformHandle fMatrixHandle;
         GrGLSLProgramDataManager::UniformHandle fVectorHandle;

         typedef GrGLSLFragmentProcessor INHERITED;
     };

 private:
     ColorMatrixEffect(const SkColorMatrix& matrix) : fMatrix(matrix) {
         this->initClassID<ColorMatrixEffect>();
     }

     GrGLSLFragmentProcessor* onCreateGLSLInstance() const override {
         return new GLSLProcessor(*this);
     }

     virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
                                        GrProcessorKeyBuilder* b) const override {
         GLSLProcessor::GenKey(*this, caps, b);
     }

     bool onIsEqual(const GrFragmentProcessor& s) const override {
         const ColorMatrixEffect& cme = s.cast<ColorMatrixEffect>();
         return cme.fMatrix == fMatrix;
     }

     void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
         // We only bother to check whether the alpha channel will be constant. If SkColorMatrix had
         // type flags it might be worth checking the other components.

         // The matrix is defined such the 4th row determines the output alpha. The first four
         // columns of that row multiply the input r, g, b, and a, respectively, and the last column
         // is the "translation".
         static const uint32_t kRGBAFlags[] = {
             kR_GrColorComponentFlag,
             kG_GrColorComponentFlag,
             kB_GrColorComponentFlag,
             kA_GrColorComponentFlag
         };
         static const int kShifts[] = {
             GrColor_SHIFT_R, GrColor_SHIFT_G, GrColor_SHIFT_B, GrColor_SHIFT_A,
         };
         enum {
             kAlphaRowStartIdx = 15,
             kAlphaRowTranslateIdx = 19,
         };

         SkScalar outputA = 0;
         for (int i = 0; i < 4; ++i) {
             // If any relevant component of the color to be passed through the matrix is non-const
             // then we can't know the final result.
             if (0 != fMatrix.fMat[kAlphaRowStartIdx + i]) {
                 if (!(inout->validFlags() & kRGBAFlags[i])) {
                     inout->setToUnknown(GrInvariantOutput::kWill_ReadInput);
                     return;
                 } else {
                     uint32_t component = (inout->color() >> kShifts[i]) & 0xFF;
                     outputA += fMatrix.fMat[kAlphaRowStartIdx + i] * component;
                 }
             }
         }
         outputA += fMatrix.fMat[kAlphaRowTranslateIdx];
         // We pin the color to [0,1]. This would happen to the *final* color output from the frag
         // shader but currently the effect does not pin its own output. So in the case of over/
         // underflow this may deviate from the actual result. Maybe the effect should pin its
         // result if the matrix could over/underflow for any component?
         inout->setToOther(kA_GrColorComponentFlag,
                           static_cast<uint8_t>(SkScalarPin(outputA, 0, 255)) << GrColor_SHIFT_A,
                           GrInvariantOutput::kWill_ReadInput);
     }

     SkColorMatrix fMatrix;

     typedef GrFragmentProcessor INHERITED;
 };

 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(ColorMatrixEffect);

 const GrFragmentProcessor* ColorMatrixEffect::TestCreate(GrProcessorTestData* d) {
     SkColorMatrix colorMatrix;
     for (size_t i = 0; i < SK_ARRAY_COUNT(colorMatrix.fMat); ++i) {
         colorMatrix.fMat[i] = d->fRandom->nextSScalar1();
     }
     return ColorMatrixEffect::Create(colorMatrix);
 }

 const GrFragmentProcessor* SkColorMatrixFilter::asFragmentProcessor(GrContext*) const {
     return ColorMatrixEffect::Create(fMatrix);
 }

 #endif

 #ifndef SK_IGNORE_TO_STRING
 void SkColorMatrixFilter::toString(SkString* str) const {
     str->append("SkColorMatrixFilter: ");

     str->append("matrix: (");
     for (int i = 0; i < 20; ++i) {
         str->appendScalar(fMatrix.fMat[i]);
         if (i < 19) {
             str->append(", ");
         }
     }
     str->append(")");
 }
 #endif

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

 static SkScalar byte_to_scale(U8CPU byte) {
     if (0xFF == byte) {
         // want to get this exact
         return 1;
     } else {
         return byte * 0.00392156862745f;
     }
 }

 SkColorFilter* SkColorMatrixFilter::CreateLightingFilter(SkColor mul, SkColor add) {
     SkColorMatrix matrix;
     matrix.setScale(byte_to_scale(SkColorGetR(mul)),
                     byte_to_scale(SkColorGetG(mul)),
                     byte_to_scale(SkColorGetB(mul)),
                     1);
     matrix.postTranslate(SkIntToScalar(SkColorGetR(add)),
                          SkIntToScalar(SkColorGetG(add)),
                          SkIntToScalar(SkColorGetB(add)),
                          0);
     return SkColorMatrixFilter::Create(matrix);
 }
	/*
	* Copyright 2011 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkColorMatrixFilter.h"
	#include "SkColorMatrix.h"
	#include "SkColorPriv.h"
	#include "SkNx.h"
	#include "SkReadBuffer.h"
	#include "SkWriteBuffer.h"
	#include "SkUnPreMultiply.h"
	#include "SkString.h"

	#define SK_PMORDER_INDEX_A (SK_A32_SHIFT / 8)
	#define SK_PMORDER_INDEX_R (SK_R32_SHIFT / 8)
	#define SK_PMORDER_INDEX_G (SK_G32_SHIFT / 8)
	#define SK_PMORDER_INDEX_B (SK_B32_SHIFT / 8)

	static void transpose_to_pmorder(float dst[20], const float src[20]) {
	const float* srcR = src + 0;
	const float* srcG = src + 5;
	const float* srcB = src + 10;
	const float* srcA = src + 15;

	for (int i = 0; i < 20; i += 4) {
	dst[i + SK_PMORDER_INDEX_A] = *srcA++;
	dst[i + SK_PMORDER_INDEX_R] = *srcR++;
	dst[i + SK_PMORDER_INDEX_G] = *srcG++;
	dst[i + SK_PMORDER_INDEX_B] = *srcB++;
	}
	}

	// src is [20] but some compilers won't accept __restrict__ on anything
	// but an raw pointer or reference
	void SkColorMatrixFilter::initState(const SkScalar* SK_RESTRICT src) {
	transpose_to_pmorder(fTranspose, src);

	const float* array = fMatrix.fMat;

	// check if we have to munge Alpha
	bool changesAlpha = (array[15] \|\| array[16] \|\| array[17] \|\| (array[18] - 1) \|\| array[19]);
	bool usesAlpha = (array[3] \|\| array[8] \|\| array[13]);

	if (changesAlpha \|\| usesAlpha) {
	fFlags = changesAlpha ? 0 : SkColorFilter::kAlphaUnchanged_Flag;
	} else {
	fFlags = SkColorFilter::kAlphaUnchanged_Flag;
	}
	}

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

	SkColorMatrixFilter::SkColorMatrixFilter(const SkColorMatrix& cm) : fMatrix(cm) {
	this->initState(cm.fMat);
	}

	SkColorMatrixFilter::SkColorMatrixFilter(const SkScalar array[20]) {
	memcpy(fMatrix.fMat, array, 20 * sizeof(SkScalar));
	this->initState(array);
	}

	uint32_t SkColorMatrixFilter::getFlags() const {
	return this->INHERITED::getFlags() \| fFlags;
	}

	static Sk4f scale_rgb(float scale) {
	static_assert(SK_A32_SHIFT == 24, "Alpha is lane 3");
	return Sk4f(scale, scale, scale, 1);
	}

	static Sk4f premul(const Sk4f& x) {
	return x * scale_rgb(x.kth<SK_A32_SHIFT/8>());
	}

	static Sk4f unpremul(const Sk4f& x) {
	return x * scale_rgb(1 / x.kth<SK_A32_SHIFT/8>()); // TODO: fast/approx invert?
	}

	static Sk4f clamp_0_1(const Sk4f& x) {
	return Sk4f::Max(Sk4f::Min(x, Sk4f(1)), Sk4f(0));
	}

	static SkPMColor round(const Sk4f& x) {
	SkPMColor c;
	SkNx_cast<uint8_t>(x * Sk4f(255) + Sk4f(0.5f)).store((uint8_t*)&c);
	return c;
	}

	void SkColorMatrixFilter::filterSpan(const SkPMColor src[], int count, SkPMColor dst[]) const {
	// c0-c3 are already in [0,1].
	const Sk4f c0 = Sk4f::Load(fTranspose + 0);
	const Sk4f c1 = Sk4f::Load(fTranspose + 4);
	const Sk4f c2 = Sk4f::Load(fTranspose + 8);
	const Sk4f c3 = Sk4f::Load(fTranspose + 12);
	// c4 (the translate vector) is in [0, 255]. Bring it back to [0,1].
	const Sk4f c4 = Sk4f::Load(fTranspose + 16)*Sk4f(1.0f/255);

	// todo: we could cache this in the constructor...
	SkPMColor matrix_translate_pmcolor = round(premul(clamp_0_1(c4)));

	for (int i = 0; i < count; i++) {
	const SkPMColor src_c = src[i];
	if (0 == src_c) {
	dst[i] = matrix_translate_pmcolor;
	continue;
	}

	Sk4f srcf = SkNx_cast<float>(Sk4b::Load((const uint8_t)&src_c)) Sk4f(1.0f/255);

	if (0xFF != SkGetPackedA32(src_c)) {
	srcf = unpremul(srcf);
	}

	Sk4f r4 = SkNx_dup<SK_R32_SHIFT/8>(srcf);
	Sk4f g4 = SkNx_dup<SK_G32_SHIFT/8>(srcf);
	Sk4f b4 = SkNx_dup<SK_B32_SHIFT/8>(srcf);
	Sk4f a4 = SkNx_dup<SK_A32_SHIFT/8>(srcf);

	// apply matrix
	Sk4f dst4 = c0 * r4 + c1 * g4 + c2 * b4 + c3 * a4 + c4;

	// clamp, re-premul, and write
	dst[i] = round(premul(clamp_0_1(dst4)));
	}
	}

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

	void SkColorMatrixFilter::flatten(SkWriteBuffer& buffer) const {
	SkASSERT(sizeof(fMatrix.fMat)/sizeof(SkScalar) == 20);
	buffer.writeScalarArray(fMatrix.fMat, 20);
	}

	SkFlattenable* SkColorMatrixFilter::CreateProc(SkReadBuffer& buffer) {
	SkColorMatrix matrix;
	if (buffer.readScalarArray(matrix.fMat, 20)) {
	return Create(matrix);
	}
	return nullptr;
	}

	bool SkColorMatrixFilter::asColorMatrix(SkScalar matrix[20]) const {
	if (matrix) {
	memcpy(matrix, fMatrix.fMat, 20 * sizeof(SkScalar));
	}
	return true;
	}

	SkColorFilter* SkColorMatrixFilter::newComposed(const SkColorFilter* innerFilter) const {
	SkScalar innerMatrix[20];
	if (innerFilter->asColorMatrix(innerMatrix) && !SkColorMatrix::NeedsClamping(innerMatrix)) {
	SkScalar concat[20];
	SkColorMatrix::SetConcat(concat, fMatrix.fMat, innerMatrix);
	return SkColorMatrixFilter::Create(concat);
	}
	return nullptr;
	}

	#if SK_SUPPORT_GPU
	#include "GrFragmentProcessor.h"
	#include "GrInvariantOutput.h"
	#include "glsl/GrGLSLFragmentProcessor.h"
	#include "glsl/GrGLSLFragmentShaderBuilder.h"
	#include "glsl/GrGLSLProgramDataManager.h"
	#include "glsl/GrGLSLUniformHandler.h"

	class ColorMatrixEffect : public GrFragmentProcessor {
	public:
	static const GrFragmentProcessor* Create(const SkColorMatrix& matrix) {
	return new ColorMatrixEffect(matrix);
	}

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

	GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

	class GLSLProcessor : public GrGLSLFragmentProcessor {
	public:
	// this class always generates the same code.
	static void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder* b) {}

	GLSLProcessor(const GrProcessor&) {}

	virtual void emitCode(EmitArgs& args) override {
	GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
	fMatrixHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
	kMat44f_GrSLType, kDefault_GrSLPrecision,
	"ColorMatrix");
	fVectorHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
	kVec4f_GrSLType, kDefault_GrSLPrecision,
	"ColorMatrixVector");

	if (nullptr == args.fInputColor) {
	// could optimize this case, but we aren't for now.
	args.fInputColor = "vec4(1)";
	}
	GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
	// The max() is to guard against 0 / 0 during unpremul when the incoming color is
	// transparent black.
	fragBuilder->codeAppendf("\tfloat nonZeroAlpha = max(%s.a, 0.00001);\n",
	args.fInputColor);
	fragBuilder->codeAppendf("\t%s = %s * vec4(%s.rgb / nonZeroAlpha, nonZeroAlpha) + %s;\n",
	args.fOutputColor,
	uniformHandler->getUniformCStr(fMatrixHandle),
	args.fInputColor,
	uniformHandler->getUniformCStr(fVectorHandle));
	fragBuilder->codeAppendf("\t%s = clamp(%s, 0.0, 1.0);\n",
	args.fOutputColor, args.fOutputColor);
	fragBuilder->codeAppendf("\t%s.rgb *= %s.a;\n", args.fOutputColor, args.fOutputColor);
	}

	protected:
	virtual void onSetData(const GrGLSLProgramDataManager& uniManager,
	const GrProcessor& proc) override {
	const ColorMatrixEffect& cme = proc.cast<ColorMatrixEffect>();
	const float* m = cme.fMatrix.fMat;
	// The GL matrix is transposed from SkColorMatrix.
	float mt[] = {
	m[0], m[5], m[10], m[15],
	m[1], m[6], m[11], m[16],
	m[2], m[7], m[12], m[17],
	m[3], m[8], m[13], m[18],
	};
	static const float kScale = 1.0f / 255.0f;
	float vec[] = {
	m[4] * kScale, m[9] * kScale, m[14] * kScale, m[19] * kScale,
	};
	uniManager.setMatrix4fv(fMatrixHandle, 1, mt);
	uniManager.set4fv(fVectorHandle, 1, vec);
	}

	private:
	GrGLSLProgramDataManager::UniformHandle fMatrixHandle;
	GrGLSLProgramDataManager::UniformHandle fVectorHandle;

	typedef GrGLSLFragmentProcessor INHERITED;
	};

	private:
	ColorMatrixEffect(const SkColorMatrix& matrix) : fMatrix(matrix) {
	this->initClassID<ColorMatrixEffect>();
	}

	GrGLSLFragmentProcessor* onCreateGLSLInstance() const override {
	return new GLSLProcessor(*this);
	}

	virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
	GrProcessorKeyBuilder* b) const override {
	GLSLProcessor::GenKey(*this, caps, b);
	}

	bool onIsEqual(const GrFragmentProcessor& s) const override {
	const ColorMatrixEffect& cme = s.cast<ColorMatrixEffect>();
	return cme.fMatrix == fMatrix;
	}

	void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
	// We only bother to check whether the alpha channel will be constant. If SkColorMatrix had
	// type flags it might be worth checking the other components.

	// The matrix is defined such the 4th row determines the output alpha. The first four
	// columns of that row multiply the input r, g, b, and a, respectively, and the last column
	// is the "translation".
	static const uint32_t kRGBAFlags[] = {
	kR_GrColorComponentFlag,
	kG_GrColorComponentFlag,
	kB_GrColorComponentFlag,
	kA_GrColorComponentFlag
	};
	static const int kShifts[] = {
	GrColor_SHIFT_R, GrColor_SHIFT_G, GrColor_SHIFT_B, GrColor_SHIFT_A,
	};
	enum {
	kAlphaRowStartIdx = 15,
	kAlphaRowTranslateIdx = 19,
	};

	SkScalar outputA = 0;
	for (int i = 0; i < 4; ++i) {
	// If any relevant component of the color to be passed through the matrix is non-const
	// then we can't know the final result.
	if (0 != fMatrix.fMat[kAlphaRowStartIdx + i]) {
	if (!(inout->validFlags() & kRGBAFlags[i])) {
	inout->setToUnknown(GrInvariantOutput::kWill_ReadInput);
	return;
	} else {
	uint32_t component = (inout->color() >> kShifts[i]) & 0xFF;
	outputA += fMatrix.fMat[kAlphaRowStartIdx + i] * component;
	}
	}
	}
	outputA += fMatrix.fMat[kAlphaRowTranslateIdx];
	// We pin the color to [0,1]. This would happen to the final color output from the frag
	// shader but currently the effect does not pin its own output. So in the case of over/
	// underflow this may deviate from the actual result. Maybe the effect should pin its
	// result if the matrix could over/underflow for any component?
	inout->setToOther(kA_GrColorComponentFlag,
	static_cast<uint8_t>(SkScalarPin(outputA, 0, 255)) << GrColor_SHIFT_A,
	GrInvariantOutput::kWill_ReadInput);
	}

	SkColorMatrix fMatrix;

	typedef GrFragmentProcessor INHERITED;
	};

	GR_DEFINE_FRAGMENT_PROCESSOR_TEST(ColorMatrixEffect);

	const GrFragmentProcessor* ColorMatrixEffect::TestCreate(GrProcessorTestData* d) {
	SkColorMatrix colorMatrix;
	for (size_t i = 0; i < SK_ARRAY_COUNT(colorMatrix.fMat); ++i) {
	colorMatrix.fMat[i] = d->fRandom->nextSScalar1();
	}
	return ColorMatrixEffect::Create(colorMatrix);
	}

	const GrFragmentProcessor* SkColorMatrixFilter::asFragmentProcessor(GrContext*) const {
	return ColorMatrixEffect::Create(fMatrix);
	}

	#endif

	#ifndef SK_IGNORE_TO_STRING
	void SkColorMatrixFilter::toString(SkString* str) const {
	str->append("SkColorMatrixFilter: ");

	str->append("matrix: (");
	for (int i = 0; i < 20; ++i) {
	str->appendScalar(fMatrix.fMat[i]);
	if (i < 19) {
	str->append(", ");
	}
	}
	str->append(")");
	}
	#endif

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

	static SkScalar byte_to_scale(U8CPU byte) {
	if (0xFF == byte) {
	// want to get this exact
	return 1;
	} else {
	return byte * 0.00392156862745f;
	}
	}

	SkColorFilter* SkColorMatrixFilter::CreateLightingFilter(SkColor mul, SkColor add) {
	SkColorMatrix matrix;
	matrix.setScale(byte_to_scale(SkColorGetR(mul)),
	byte_to_scale(SkColorGetG(mul)),
	byte_to_scale(SkColorGetB(mul)),
	1);
	matrix.postTranslate(SkIntToScalar(SkColorGetR(add)),
	SkIntToScalar(SkColorGetG(add)),
	SkIntToScalar(SkColorGetB(add)),
	0);
	return SkColorMatrixFilter::Create(matrix);
	}