The Tor Browser: gfx/skia/trunk/src/effects/SkPerlinNoiseShader.cpp@6474c204b198 (annotated)

gfx/skia/trunk/src/effects/SkPerlinNoiseShader.cpp@6474c204b198 (annotated)

gfx/skia/trunk/src/effects/SkPerlinNoiseShader.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkDither.h"
 #include "SkPerlinNoiseShader.h"
 #include "SkColorFilter.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkShader.h"
 #include "SkUnPreMultiply.h"
 #include "SkString.h"
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "GrCoordTransform.h"
 #include "gl/GrGLEffect.h"
 #include "GrTBackendEffectFactory.h"
 #include "SkGr.h"
 #endif
 static const int kBlockSize = 256;
 static const int kBlockMask = kBlockSize - 1;
 static const int kPerlinNoise = 4096;
 static const int kRandMaximum = SK_MaxS32; // 2**31 - 1
 namespace {
 // noiseValue is the color component's value (or color)
 // limitValue is the maximum perlin noise array index value allowed
 // newValue is the current noise dimension (either width or height)
 inline int checkNoise(int noiseValue, int limitValue, int newValue) {
     // If the noise value would bring us out of bounds of the current noise array while we are
     // stiching noise tiles together, wrap the noise around the current dimension of the noise to
     // stay within the array bounds in a continuous fashion (so that tiling lines are not visible)
     if (noiseValue >= limitValue) {
         noiseValue -= newValue;
     }
     if (noiseValue >= limitValue - 1) {
         noiseValue -= newValue - 1;
     }
     return noiseValue;
 }
 inline SkScalar smoothCurve(SkScalar t) {
     static const SkScalar SK_Scalar3 = 3.0f;
     // returns t * t * (3 - 2 * t)
     return SkScalarMul(SkScalarSquare(t), SK_Scalar3 - 2 * t);
 }
 bool perlin_noise_type_is_valid(SkPerlinNoiseShader::Type type) {
     return (SkPerlinNoiseShader::kFractalNoise_Type == type) ||
            (SkPerlinNoiseShader::kTurbulence_Type == type);
 }
 } // end namespace
 struct SkPerlinNoiseShader::StitchData {
     StitchData()
       : fWidth(0)
       , fWrapX(0)
       , fHeight(0)
       , fWrapY(0)
     {}
     bool operator==(const StitchData& other) const {
         return fWidth == other.fWidth &&
                fWrapX == other.fWrapX &&
                fHeight == other.fHeight &&
                fWrapY == other.fWrapY;
     }
     int fWidth; // How much to subtract to wrap for stitching.
     int fWrapX; // Minimum value to wrap.
     int fHeight;
     int fWrapY;
 };
 struct SkPerlinNoiseShader::PaintingData {
     PaintingData(const SkISize& tileSize, SkScalar seed,
                  SkScalar baseFrequencyX, SkScalar baseFrequencyY)
       : fTileSize(tileSize)
       , fBaseFrequency(SkPoint::Make(baseFrequencyX, baseFrequencyY))
     {
         this->init(seed);
         if (!fTileSize.isEmpty()) {
             this->stitch();
         }
 #if SK_SUPPORT_GPU && !defined(SK_USE_SIMPLEX_NOISE)
         fPermutationsBitmap.setConfig(SkImageInfo::MakeA8(kBlockSize, 1));
         fPermutationsBitmap.setPixels(fLatticeSelector);
         fNoiseBitmap.setConfig(SkImageInfo::MakeN32Premul(kBlockSize, 4));
         fNoiseBitmap.setPixels(fNoise[0][0]);
 #endif
     }
     int         fSeed;
     uint8_t     fLatticeSelector[kBlockSize];
     uint16_t    fNoise[4][kBlockSize][2];
     SkPoint     fGradient[4][kBlockSize];
     SkISize     fTileSize;
     SkVector    fBaseFrequency;
     StitchData  fStitchDataInit;
 private:
 #if SK_SUPPORT_GPU && !defined(SK_USE_SIMPLEX_NOISE)
     SkBitmap   fPermutationsBitmap;
     SkBitmap   fNoiseBitmap;
 #endif
     inline int random()  {
         static const int gRandAmplitude = 16807; // 7**5; primitive root of m
         static const int gRandQ = 127773; // m / a
         static const int gRandR = 2836; // m % a
         int result = gRandAmplitude * (fSeed % gRandQ) - gRandR * (fSeed / gRandQ);
         if (result <= 0)
             result += kRandMaximum;
         fSeed = result;
         return result;
     }
     // Only called once. Could be part of the constructor.
     void init(SkScalar seed)
     {
         static const SkScalar gInvBlockSizef = SkScalarInvert(SkIntToScalar(kBlockSize));
         // According to the SVG spec, we must truncate (not round) the seed value.
         fSeed = SkScalarTruncToInt(seed);
         // The seed value clamp to the range [1, kRandMaximum - 1].
         if (fSeed <= 0) {
             fSeed = -(fSeed % (kRandMaximum - 1)) + 1;
         }
         if (fSeed > kRandMaximum - 1) {
             fSeed = kRandMaximum - 1;
         }
         for (int channel = 0; channel < 4; ++channel) {
             for (int i = 0; i < kBlockSize; ++i) {
                 fLatticeSelector[i] = i;
                 fNoise[channel][i][0] = (random() % (2 * kBlockSize));
                 fNoise[channel][i][1] = (random() % (2 * kBlockSize));
             }
         }
         for (int i = kBlockSize - 1; i > 0; --i) {
             int k = fLatticeSelector[i];
             int j = random() % kBlockSize;
             SkASSERT(j >= 0);
             SkASSERT(j < kBlockSize);
             fLatticeSelector[i] = fLatticeSelector[j];
             fLatticeSelector[j] = k;
         }
         // Perform the permutations now
         {
             // Copy noise data
             uint16_t noise[4][kBlockSize][2];
             for (int i = 0; i < kBlockSize; ++i) {
                 for (int channel = 0; channel < 4; ++channel) {
                     for (int j = 0; j < 2; ++j) {
                         noise[channel][i][j] = fNoise[channel][i][j];
                     }
                 }
             }
             // Do permutations on noise data
             for (int i = 0; i < kBlockSize; ++i) {
                 for (int channel = 0; channel < 4; ++channel) {
                     for (int j = 0; j < 2; ++j) {
                         fNoise[channel][i][j] = noise[channel][fLatticeSelector[i]][j];
                     }
                 }
             }
         }
         // Half of the largest possible value for 16 bit unsigned int
         static const SkScalar gHalfMax16bits = 32767.5f;
         // Compute gradients from permutated noise data
         for (int channel = 0; channel < 4; ++channel) {
             for (int i = 0; i < kBlockSize; ++i) {
                 fGradient[channel][i] = SkPoint::Make(
                     SkScalarMul(SkIntToScalar(fNoise[channel][i][0] - kBlockSize),
                                 gInvBlockSizef),
                     SkScalarMul(SkIntToScalar(fNoise[channel][i][1] - kBlockSize),
                                 gInvBlockSizef));
                 fGradient[channel][i].normalize();
                 // Put the normalized gradient back into the noise data
                 fNoise[channel][i][0] = SkScalarRoundToInt(SkScalarMul(
                     fGradient[channel][i].fX + SK_Scalar1, gHalfMax16bits));
                 fNoise[channel][i][1] = SkScalarRoundToInt(SkScalarMul(
                     fGradient[channel][i].fY + SK_Scalar1, gHalfMax16bits));
             }
         }
     }
     // Only called once. Could be part of the constructor.
     void stitch() {
         SkScalar tileWidth  = SkIntToScalar(fTileSize.width());
         SkScalar tileHeight = SkIntToScalar(fTileSize.height());
         SkASSERT(tileWidth > 0 && tileHeight > 0);
         // When stitching tiled turbulence, the frequencies must be adjusted
         // so that the tile borders will be continuous.
         if (fBaseFrequency.fX) {
             SkScalar lowFrequencx =
                 SkScalarFloorToScalar(tileWidth * fBaseFrequency.fX) / tileWidth;
             SkScalar highFrequencx =
                 SkScalarCeilToScalar(tileWidth * fBaseFrequency.fX) / tileWidth;
             // BaseFrequency should be non-negative according to the standard.
             if (SkScalarDiv(fBaseFrequency.fX, lowFrequencx) <
                 SkScalarDiv(highFrequencx, fBaseFrequency.fX)) {
                 fBaseFrequency.fX = lowFrequencx;
             } else {
                 fBaseFrequency.fX = highFrequencx;
             }
         }
         if (fBaseFrequency.fY) {
             SkScalar lowFrequency =
                 SkScalarFloorToScalar(tileHeight * fBaseFrequency.fY) / tileHeight;
             SkScalar highFrequency =
                 SkScalarCeilToScalar(tileHeight * fBaseFrequency.fY) / tileHeight;
             if (SkScalarDiv(fBaseFrequency.fY, lowFrequency) <
                 SkScalarDiv(highFrequency, fBaseFrequency.fY)) {
                 fBaseFrequency.fY = lowFrequency;
             } else {
                 fBaseFrequency.fY = highFrequency;
             }
         }
         // Set up TurbulenceInitial stitch values.
         fStitchDataInit.fWidth  =
             SkScalarRoundToInt(tileWidth * fBaseFrequency.fX);
         fStitchDataInit.fWrapX  = kPerlinNoise + fStitchDataInit.fWidth;
         fStitchDataInit.fHeight =
             SkScalarRoundToInt(tileHeight * fBaseFrequency.fY);
         fStitchDataInit.fWrapY  = kPerlinNoise + fStitchDataInit.fHeight;
     }
 public:
 #if SK_SUPPORT_GPU && !defined(SK_USE_SIMPLEX_NOISE)
     const SkBitmap& getPermutationsBitmap() const { return fPermutationsBitmap; }
     const SkBitmap& getNoiseBitmap() const { return fNoiseBitmap; }
 #endif
 };
 SkShader* SkPerlinNoiseShader::CreateFractalNoise(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                                                   int numOctaves, SkScalar seed,
                                                   const SkISize* tileSize) {
     return SkNEW_ARGS(SkPerlinNoiseShader, (kFractalNoise_Type, baseFrequencyX, baseFrequencyY,
                                             numOctaves, seed, tileSize));
 }
 SkShader* SkPerlinNoiseShader::CreateTubulence(SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                                               int numOctaves, SkScalar seed,
                                               const SkISize* tileSize) {
     return SkNEW_ARGS(SkPerlinNoiseShader, (kTurbulence_Type, baseFrequencyX, baseFrequencyY,
                                             numOctaves, seed, tileSize));
 }
 SkPerlinNoiseShader::SkPerlinNoiseShader(SkPerlinNoiseShader::Type type,
                                          SkScalar baseFrequencyX,
                                          SkScalar baseFrequencyY,
                                          int numOctaves,
                                          SkScalar seed,
                                          const SkISize* tileSize)
   : fType(type)
   , fBaseFrequencyX(baseFrequencyX)
   , fBaseFrequencyY(baseFrequencyY)
   , fNumOctaves(numOctaves > 255 ? 255 : numOctaves/*[0,255] octaves allowed*/)
   , fSeed(seed)
   , fTileSize(NULL == tileSize ? SkISize::Make(0, 0) : *tileSize)
   , fStitchTiles(!fTileSize.isEmpty())
 {
     SkASSERT(numOctaves >= 0 && numOctaves < 256);
     fMatrix.reset();
     fPaintingData = SkNEW_ARGS(PaintingData, (fTileSize, fSeed, fBaseFrequencyX, fBaseFrequencyY));
 }
 SkPerlinNoiseShader::SkPerlinNoiseShader(SkReadBuffer& buffer)
     : INHERITED(buffer)
 {
     fType           = (SkPerlinNoiseShader::Type) buffer.readInt();
     fBaseFrequencyX = buffer.readScalar();
     fBaseFrequencyY = buffer.readScalar();
     fNumOctaves     = buffer.readInt();
     fSeed           = buffer.readScalar();
     fStitchTiles    = buffer.readBool();
     fTileSize.fWidth  = buffer.readInt();
     fTileSize.fHeight = buffer.readInt();
     fMatrix.reset();
     fPaintingData = SkNEW_ARGS(PaintingData, (fTileSize, fSeed, fBaseFrequencyX, fBaseFrequencyY));
     buffer.validate(perlin_noise_type_is_valid(fType) &&
                     (fNumOctaves >= 0) && (fNumOctaves <= 255) &&
                     (fStitchTiles != fTileSize.isEmpty()));
 }
 SkPerlinNoiseShader::~SkPerlinNoiseShader() {
     // Safety, should have been done in endContext()
     SkDELETE(fPaintingData);
 }
 void SkPerlinNoiseShader::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeInt((int) fType);
     buffer.writeScalar(fBaseFrequencyX);
     buffer.writeScalar(fBaseFrequencyY);
     buffer.writeInt(fNumOctaves);
     buffer.writeScalar(fSeed);
     buffer.writeBool(fStitchTiles);
     buffer.writeInt(fTileSize.fWidth);
     buffer.writeInt(fTileSize.fHeight);
 }
 SkScalar SkPerlinNoiseShader::noise2D(int channel, const PaintingData& paintingData,
                                       const StitchData& stitchData,
                                       const SkPoint& noiseVector) const {
     struct Noise {
         int noisePositionIntegerValue;
         SkScalar noisePositionFractionValue;
         Noise(SkScalar component)
         {
             SkScalar position = component + kPerlinNoise;
             noisePositionIntegerValue = SkScalarFloorToInt(position);
             noisePositionFractionValue = position - SkIntToScalar(noisePositionIntegerValue);
         }
     };
     Noise noiseX(noiseVector.x());
     Noise noiseY(noiseVector.y());
     SkScalar u, v;
     // If stitching, adjust lattice points accordingly.
     if (fStitchTiles) {
         noiseX.noisePositionIntegerValue =
             checkNoise(noiseX.noisePositionIntegerValue, stitchData.fWrapX, stitchData.fWidth);
         noiseY.noisePositionIntegerValue =
             checkNoise(noiseY.noisePositionIntegerValue, stitchData.fWrapY, stitchData.fHeight);
     }
     noiseX.noisePositionIntegerValue &= kBlockMask;
     noiseY.noisePositionIntegerValue &= kBlockMask;
     int latticeIndex =
         paintingData.fLatticeSelector[noiseX.noisePositionIntegerValue] +
         noiseY.noisePositionIntegerValue;
     int nextLatticeIndex =
         paintingData.fLatticeSelector[(noiseX.noisePositionIntegerValue + 1) & kBlockMask] +
         noiseY.noisePositionIntegerValue;
     SkScalar sx = smoothCurve(noiseX.noisePositionFractionValue);
     SkScalar sy = smoothCurve(noiseY.noisePositionFractionValue);
     // This is taken 1:1 from SVG spec: http://www.w3.org/TR/SVG11/filters.html#feTurbulenceElement
     SkPoint fractionValue = SkPoint::Make(noiseX.noisePositionFractionValue,
                                           noiseY.noisePositionFractionValue); // Offset (0,0)
     u = paintingData.fGradient[channel][latticeIndex & kBlockMask].dot(fractionValue);
     fractionValue.fX -= SK_Scalar1; // Offset (-1,0)
     v = paintingData.fGradient[channel][nextLatticeIndex & kBlockMask].dot(fractionValue);
     SkScalar a = SkScalarInterp(u, v, sx);
     fractionValue.fY -= SK_Scalar1; // Offset (-1,-1)
     v = paintingData.fGradient[channel][(nextLatticeIndex + 1) & kBlockMask].dot(fractionValue);
     fractionValue.fX = noiseX.noisePositionFractionValue; // Offset (0,-1)
     u = paintingData.fGradient[channel][(latticeIndex + 1) & kBlockMask].dot(fractionValue);
     SkScalar b = SkScalarInterp(u, v, sx);
     return SkScalarInterp(a, b, sy);
 }
 SkScalar SkPerlinNoiseShader::calculateTurbulenceValueForPoint(int channel,
                                                                const PaintingData& paintingData,
                                                                StitchData& stitchData,
                                                                const SkPoint& point) const {
     if (fStitchTiles) {
         // Set up TurbulenceInitial stitch values.
         stitchData = paintingData.fStitchDataInit;
     }
     SkScalar turbulenceFunctionResult = 0;
     SkPoint noiseVector(SkPoint::Make(SkScalarMul(point.x(), paintingData.fBaseFrequency.fX),
                                       SkScalarMul(point.y(), paintingData.fBaseFrequency.fY)));
     SkScalar ratio = SK_Scalar1;
     for (int octave = 0; octave < fNumOctaves; ++octave) {
         SkScalar noise = noise2D(channel, paintingData, stitchData, noiseVector);
         turbulenceFunctionResult += SkScalarDiv(
             (fType == kFractalNoise_Type) ? noise : SkScalarAbs(noise), ratio);
         noiseVector.fX *= 2;
         noiseVector.fY *= 2;
         ratio *= 2;
         if (fStitchTiles) {
             // Update stitch values
             stitchData.fWidth  *= 2;
             stitchData.fWrapX   = stitchData.fWidth + kPerlinNoise;
             stitchData.fHeight *= 2;
             stitchData.fWrapY   = stitchData.fHeight + kPerlinNoise;
         }
     }
     // The value of turbulenceFunctionResult comes from ((turbulenceFunctionResult) + 1) / 2
     // by fractalNoise and (turbulenceFunctionResult) by turbulence.
     if (fType == kFractalNoise_Type) {
         turbulenceFunctionResult =
             SkScalarMul(turbulenceFunctionResult, SK_ScalarHalf) + SK_ScalarHalf;
     }
     if (channel == 3) { // Scale alpha by paint value
         turbulenceFunctionResult = SkScalarMul(turbulenceFunctionResult,
             SkScalarDiv(SkIntToScalar(getPaintAlpha()), SkIntToScalar(255)));
     }
     // Clamp result
     return SkScalarPin(turbulenceFunctionResult, 0, SK_Scalar1);
 }
 SkPMColor SkPerlinNoiseShader::shade(const SkPoint& point, StitchData& stitchData) const {
     SkMatrix matrix = fMatrix;
     matrix.postConcat(getLocalMatrix());
     SkMatrix invMatrix;
     if (!matrix.invert(&invMatrix)) {
         invMatrix.reset();
     } else {
         invMatrix.postConcat(invMatrix); // Square the matrix
     }
     // This (1,1) translation is due to WebKit's 1 based coordinates for the noise
     // (as opposed to 0 based, usually). The same adjustment is in the setData() function.
     matrix.postTranslate(SK_Scalar1, SK_Scalar1);
     SkPoint newPoint;
     matrix.mapPoints(&newPoint, &point, 1);
     invMatrix.mapPoints(&newPoint, &newPoint, 1);
     newPoint.fX = SkScalarRoundToScalar(newPoint.fX);
     newPoint.fY = SkScalarRoundToScalar(newPoint.fY);
     U8CPU rgba[4];
     for (int channel = 3; channel >= 0; --channel) {
         rgba[channel] = SkScalarFloorToInt(255 *
             calculateTurbulenceValueForPoint(channel, *fPaintingData, stitchData, newPoint));
     }
     return SkPreMultiplyARGB(rgba[3], rgba[0], rgba[1], rgba[2]);
 }
 bool SkPerlinNoiseShader::setContext(const SkBitmap& device, const SkPaint& paint,
                                      const SkMatrix& matrix) {
     fMatrix = matrix;
     return INHERITED::setContext(device, paint, matrix);
 }
 void SkPerlinNoiseShader::shadeSpan(int x, int y, SkPMColor result[], int count) {
     SkPoint point = SkPoint::Make(SkIntToScalar(x), SkIntToScalar(y));
     StitchData stitchData;
     for (int i = 0; i < count; ++i) {
         result[i] = shade(point, stitchData);
         point.fX += SK_Scalar1;
     }
 }
 void SkPerlinNoiseShader::shadeSpan16(int x, int y, uint16_t result[], int count) {
     SkPoint point = SkPoint::Make(SkIntToScalar(x), SkIntToScalar(y));
     StitchData stitchData;
     DITHER_565_SCAN(y);
     for (int i = 0; i < count; ++i) {
         unsigned dither = DITHER_VALUE(x);
         result[i] = SkDitherRGB32To565(shade(point, stitchData), dither);
         DITHER_INC_X(x);
         point.fX += SK_Scalar1;
     }
 }
 /////////////////////////////////////////////////////////////////////
 #if SK_SUPPORT_GPU
 #include "GrTBackendEffectFactory.h"
 class GrGLNoise : public GrGLEffect {
 public:
     GrGLNoise(const GrBackendEffectFactory& factory,
               const GrDrawEffect& drawEffect);
     virtual ~GrGLNoise() {}
     static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
 protected:
     SkPerlinNoiseShader::Type           fType;
     bool                                fStitchTiles;
     int                                 fNumOctaves;
     GrGLUniformManager::UniformHandle   fBaseFrequencyUni;
     GrGLUniformManager::UniformHandle   fAlphaUni;
     GrGLUniformManager::UniformHandle   fInvMatrixUni;
 private:
     typedef GrGLEffect INHERITED;
 };
 class GrGLPerlinNoise : public GrGLNoise {
 public:
     GrGLPerlinNoise(const GrBackendEffectFactory& factory,
                     const GrDrawEffect& drawEffect)
       : GrGLNoise(factory, drawEffect) {}
     virtual ~GrGLPerlinNoise() {}
     virtual void emitCode(GrGLShaderBuilder*,
                           const GrDrawEffect&,
                           EffectKey,
                           const char* outputColor,
                           const char* inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
 private:
     GrGLUniformManager::UniformHandle fStitchDataUni;
     typedef GrGLNoise INHERITED;
 };
 class GrGLSimplexNoise : public GrGLNoise {
     // Note : This is for reference only. GrGLPerlinNoise is used for processing.
 public:
     GrGLSimplexNoise(const GrBackendEffectFactory& factory,
                      const GrDrawEffect& drawEffect)
       : GrGLNoise(factory, drawEffect) {}
     virtual ~GrGLSimplexNoise() {}
     virtual void emitCode(GrGLShaderBuilder*,
                           const GrDrawEffect&,
                           EffectKey,
                           const char* outputColor,
                           const char* inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
 private:
     GrGLUniformManager::UniformHandle fSeedUni;
     typedef GrGLNoise INHERITED;
 };
 /////////////////////////////////////////////////////////////////////
 class GrNoiseEffect : public GrEffect {
 public:
     virtual ~GrNoiseEffect() { }
     SkPerlinNoiseShader::Type type() const { return fType; }
     bool stitchTiles() const { return fStitchTiles; }
     const SkVector& baseFrequency() const { return fBaseFrequency; }
     int numOctaves() const { return fNumOctaves; }
     const SkMatrix& matrix() const { return fCoordTransform.getMatrix(); }
     uint8_t alpha() const { return fAlpha; }
     void getConstantColorComponents(GrColor*, uint32_t* validFlags) const SK_OVERRIDE {
         *validFlags = 0; // This is noise. Nothing is constant.
     }
 protected:
     virtual bool onIsEqual(const GrEffect& sBase) const SK_OVERRIDE {
         const GrNoiseEffect& s = CastEffect<GrNoiseEffect>(sBase);
         return fType == s.fType &&
                fBaseFrequency == s.fBaseFrequency &&
                fNumOctaves == s.fNumOctaves &&
                fStitchTiles == s.fStitchTiles &&
                fCoordTransform.getMatrix() == s.fCoordTransform.getMatrix() &&
                fAlpha == s.fAlpha;
     }
     GrNoiseEffect(SkPerlinNoiseShader::Type type, const SkVector& baseFrequency, int numOctaves,
                   bool stitchTiles, const SkMatrix& matrix, uint8_t alpha)
       : fType(type)
       , fBaseFrequency(baseFrequency)
       , fNumOctaves(numOctaves)
       , fStitchTiles(stitchTiles)
       , fMatrix(matrix)
       , fAlpha(alpha) {
         // This (1,1) translation is due to WebKit's 1 based coordinates for the noise
         // (as opposed to 0 based, usually). The same adjustment is in the shadeSpan() functions.
         SkMatrix m = matrix;
         m.postTranslate(SK_Scalar1, SK_Scalar1);
         fCoordTransform.reset(kLocal_GrCoordSet, m);
         this->addCoordTransform(&fCoordTransform);
         this->setWillNotUseInputColor();
     }
     SkPerlinNoiseShader::Type       fType;
     GrCoordTransform                fCoordTransform;
     SkVector                        fBaseFrequency;
     int                             fNumOctaves;
     bool                            fStitchTiles;
     SkMatrix                        fMatrix;
     uint8_t                         fAlpha;
 private:
     typedef GrEffect INHERITED;
 };
 class GrPerlinNoiseEffect : public GrNoiseEffect {
 public:
     static GrEffectRef* Create(SkPerlinNoiseShader::Type type, const SkVector& baseFrequency,
                                int numOctaves, bool stitchTiles,
                                const SkPerlinNoiseShader::StitchData& stitchData,
                                GrTexture* permutationsTexture, GrTexture* noiseTexture,
                                const SkMatrix& matrix, uint8_t alpha) {
         AutoEffectUnref effect(SkNEW_ARGS(GrPerlinNoiseEffect, (type, baseFrequency, numOctaves,
             stitchTiles, stitchData, permutationsTexture, noiseTexture, matrix, alpha)));
         return CreateEffectRef(effect);
     }
     virtual ~GrPerlinNoiseEffect() { }
     static const char* Name() { return "PerlinNoise"; }
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
         return GrTBackendEffectFactory<GrPerlinNoiseEffect>::getInstance();
     }
     const SkPerlinNoiseShader::StitchData& stitchData() const { return fStitchData; }
     typedef GrGLPerlinNoise GLEffect;
 private:
     virtual bool onIsEqual(const GrEffect& sBase) const SK_OVERRIDE {
         const GrPerlinNoiseEffect& s = CastEffect<GrPerlinNoiseEffect>(sBase);
         return INHERITED::onIsEqual(sBase) &&
                fPermutationsAccess.getTexture() == s.fPermutationsAccess.getTexture() &&
                fNoiseAccess.getTexture() == s.fNoiseAccess.getTexture() &&
                fStitchData == s.fStitchData;
     }
     GrPerlinNoiseEffect(SkPerlinNoiseShader::Type type, const SkVector& baseFrequency,
                         int numOctaves, bool stitchTiles,
                         const SkPerlinNoiseShader::StitchData& stitchData,
                         GrTexture* permutationsTexture, GrTexture* noiseTexture,
                         const SkMatrix& matrix, uint8_t alpha)
       : GrNoiseEffect(type, baseFrequency, numOctaves, stitchTiles, matrix, alpha)
       , fPermutationsAccess(permutationsTexture)
       , fNoiseAccess(noiseTexture)
       , fStitchData(stitchData) {
         this->addTextureAccess(&fPermutationsAccess);
         this->addTextureAccess(&fNoiseAccess);
     }
     GR_DECLARE_EFFECT_TEST;
     GrTextureAccess                 fPermutationsAccess;
     GrTextureAccess                 fNoiseAccess;
     SkPerlinNoiseShader::StitchData fStitchData;
     typedef GrNoiseEffect INHERITED;
 };
 class GrSimplexNoiseEffect : public GrNoiseEffect {
     // Note : This is for reference only. GrPerlinNoiseEffect is used for processing.
 public:
     static GrEffectRef* Create(SkPerlinNoiseShader::Type type, const SkVector& baseFrequency,
                                int numOctaves, bool stitchTiles, const SkScalar seed,
                                const SkMatrix& matrix, uint8_t alpha) {
         AutoEffectUnref effect(SkNEW_ARGS(GrSimplexNoiseEffect, (type, baseFrequency, numOctaves,
             stitchTiles, seed, matrix, alpha)));
         return CreateEffectRef(effect);
     }
     virtual ~GrSimplexNoiseEffect() { }
     static const char* Name() { return "SimplexNoise"; }
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
         return GrTBackendEffectFactory<GrSimplexNoiseEffect>::getInstance();
     }
     const SkScalar& seed() const { return fSeed; }
     typedef GrGLSimplexNoise GLEffect;
 private:
     virtual bool onIsEqual(const GrEffect& sBase) const SK_OVERRIDE {
         const GrSimplexNoiseEffect& s = CastEffect<GrSimplexNoiseEffect>(sBase);
         return INHERITED::onIsEqual(sBase) && fSeed == s.fSeed;
     }
     GrSimplexNoiseEffect(SkPerlinNoiseShader::Type type, const SkVector& baseFrequency,
                          int numOctaves, bool stitchTiles, const SkScalar seed,
                          const SkMatrix& matrix, uint8_t alpha)
       : GrNoiseEffect(type, baseFrequency, numOctaves, stitchTiles, matrix, alpha)
       , fSeed(seed) {
     }
     SkScalar fSeed;
     typedef GrNoiseEffect INHERITED;
 };
 /////////////////////////////////////////////////////////////////////
 GR_DEFINE_EFFECT_TEST(GrPerlinNoiseEffect);
 GrEffectRef* GrPerlinNoiseEffect::TestCreate(SkRandom* random,
                                              GrContext* context,
                                              const GrDrawTargetCaps&,
                                              GrTexture**) {
     int      numOctaves = random->nextRangeU(2, 10);
     bool     stitchTiles = random->nextBool();
     SkScalar seed = SkIntToScalar(random->nextU());
     SkISize  tileSize = SkISize::Make(random->nextRangeU(4, 4096), random->nextRangeU(4, 4096));
     SkScalar baseFrequencyX = random->nextRangeScalar(0.01f,
 .99f);
     SkScalar baseFrequencyY = random->nextRangeScalar(0.01f,
 .99f);
     SkShader* shader = random->nextBool() ?
         SkPerlinNoiseShader::CreateFractalNoise(baseFrequencyX, baseFrequencyY, numOctaves, seed,
                                                 stitchTiles ? &tileSize : NULL) :
         SkPerlinNoiseShader::CreateTubulence(baseFrequencyX, baseFrequencyY, numOctaves, seed,
                                              stitchTiles ? &tileSize : NULL);
     SkPaint paint;
     GrEffectRef* effect = shader->asNewEffect(context, paint);
     SkDELETE(shader);
     return effect;
 }
 /////////////////////////////////////////////////////////////////////
 void GrGLSimplexNoise::emitCode(GrGLShaderBuilder* builder,
                                 const GrDrawEffect&,
                                 EffectKey key,
                                 const char* outputColor,
                                 const char* inputColor,
                                 const TransformedCoordsArray& coords,
                                 const TextureSamplerArray&) {
     sk_ignore_unused_variable(inputColor);
     SkString vCoords = builder->ensureFSCoords2D(coords, 0);
     fSeedUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                    kFloat_GrSLType, "seed");
     const char* seedUni = builder->getUniformCStr(fSeedUni);
     fInvMatrixUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                         kMat33f_GrSLType, "invMatrix");
     const char* invMatrixUni = builder->getUniformCStr(fInvMatrixUni);
     fBaseFrequencyUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                             kVec2f_GrSLType, "baseFrequency");
     const char* baseFrequencyUni = builder->getUniformCStr(fBaseFrequencyUni);
     fAlphaUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                     kFloat_GrSLType, "alpha");
     const char* alphaUni = builder->getUniformCStr(fAlphaUni);
     // Add vec3 modulo 289 function
     static const GrGLShaderVar gVec3Args[] =  {
         GrGLShaderVar("x", kVec3f_GrSLType)
     };
     SkString mod289_3_funcName;
     builder->fsEmitFunction(kVec3f_GrSLType,
                             "mod289", SK_ARRAY_COUNT(gVec3Args), gVec3Args,
                             "const vec2 C = vec2(1.0 / 289.0, 289.0);\n"
                             "return x - floor(x * C.xxx) * C.yyy;", &mod289_3_funcName);
     // Add vec4 modulo 289 function
     static const GrGLShaderVar gVec4Args[] =  {
         GrGLShaderVar("x", kVec4f_GrSLType)
     };
     SkString mod289_4_funcName;
     builder->fsEmitFunction(kVec4f_GrSLType,
                             "mod289", SK_ARRAY_COUNT(gVec4Args), gVec4Args,
                             "const vec2 C = vec2(1.0 / 289.0, 289.0);\n"
                             "return x - floor(x * C.xxxx) * C.yyyy;", &mod289_4_funcName);
     // Add vec4 permute function
     SkString permuteCode;
     permuteCode.appendf("const vec2 C = vec2(34.0, 1.0);\n"
                         "return %s(((x * C.xxxx) + C.yyyy) * x);", mod289_4_funcName.c_str());
     SkString permuteFuncName;
     builder->fsEmitFunction(kVec4f_GrSLType,
                             "permute", SK_ARRAY_COUNT(gVec4Args), gVec4Args,
                             permuteCode.c_str(), &permuteFuncName);
     // Add vec4 taylorInvSqrt function
     SkString taylorInvSqrtFuncName;
     builder->fsEmitFunction(kVec4f_GrSLType,
                             "taylorInvSqrt", SK_ARRAY_COUNT(gVec4Args), gVec4Args,
                             "const vec2 C = vec2(-0.85373472095314, 1.79284291400159);\n"
                             "return x * C.xxxx + C.yyyy;", &taylorInvSqrtFuncName);
     // Add vec3 noise function
     static const GrGLShaderVar gNoiseVec3Args[] =  {
         GrGLShaderVar("v", kVec3f_GrSLType)
     };
     SkString noiseCode;
     noiseCode.append(
         "const vec2 C = vec2(1.0/6.0, 1.0/3.0);\n"
         "const vec4 D = vec4(0.0, 0.5, 1.0, 2.0);\n"
         // First corner
         "vec3 i = floor(v + dot(v, C.yyy));\n"
         "vec3 x0 = v - i + dot(i, C.xxx);\n"
         // Other corners
         "vec3 g = step(x0.yzx, x0.xyz);\n"
         "vec3 l = 1.0 - g;\n"
         "vec3 i1 = min(g.xyz, l.zxy);\n"
         "vec3 i2 = max(g.xyz, l.zxy);\n"
         "vec3 x1 = x0 - i1 + C.xxx;\n"
         "vec3 x2 = x0 - i2 + C.yyy;\n" // 2.0*C.x = 1/3 = C.y
         "vec3 x3 = x0 - D.yyy;\n" // -1.0+3.0*C.x = -0.5 = -D.y
     );
     noiseCode.appendf(
         // Permutations
         "i = %s(i);\n"
         "vec4 p = %s(%s(%s(\n"
         "         i.z + vec4(0.0, i1.z, i2.z, 1.0)) +\n"
         "         i.y + vec4(0.0, i1.y, i2.y, 1.0)) +\n"
         "         i.x + vec4(0.0, i1.x, i2.x, 1.0));\n",
         mod289_3_funcName.c_str(), permuteFuncName.c_str(), permuteFuncName.c_str(),
         permuteFuncName.c_str());
     noiseCode.append(
         // Gradients: 7x7 points over a square, mapped onto an octahedron.
         // The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
         "float n_ = 0.142857142857;\n" // 1.0/7.0
         "vec3  ns = n_ * D.wyz - D.xzx;\n"
         "vec4 j = p - 49.0 * floor(p * ns.z * ns.z);\n" // mod(p,7*7)
         "vec4 x_ = floor(j * ns.z);\n"
         "vec4 y_ = floor(j - 7.0 * x_);" // mod(j,N)
         "vec4 x = x_ *ns.x + ns.yyyy;\n"
         "vec4 y = y_ *ns.x + ns.yyyy;\n"
         "vec4 h = 1.0 - abs(x) - abs(y);\n"
         "vec4 b0 = vec4(x.xy, y.xy);\n"
         "vec4 b1 = vec4(x.zw, y.zw);\n"
     );
     noiseCode.append(
         "vec4 s0 = floor(b0) * 2.0 + 1.0;\n"
         "vec4 s1 = floor(b1) * 2.0 + 1.0;\n"
         "vec4 sh = -step(h, vec4(0.0));\n"
         "vec4 a0 = b0.xzyw + s0.xzyw * sh.xxyy;\n"
         "vec4 a1 = b1.xzyw + s1.xzyw * sh.zzww;\n"
         "vec3 p0 = vec3(a0.xy, h.x);\n"
         "vec3 p1 = vec3(a0.zw, h.y);\n"
         "vec3 p2 = vec3(a1.xy, h.z);\n"
         "vec3 p3 = vec3(a1.zw, h.w);\n"
     );
     noiseCode.appendf(
         // Normalise gradients
         "vec4 norm = %s(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));\n"
         "p0 *= norm.x;\n"
         "p1 *= norm.y;\n"
         "p2 *= norm.z;\n"
         "p3 *= norm.w;\n"
         // Mix final noise value
         "vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);\n"
         "m = m * m;\n"
         "return 42.0 * dot(m*m, vec4(dot(p0,x0), dot(p1,x1), dot(p2,x2), dot(p3,x3)));",
         taylorInvSqrtFuncName.c_str());
     SkString noiseFuncName;
     builder->fsEmitFunction(kFloat_GrSLType,
                             "snoise", SK_ARRAY_COUNT(gNoiseVec3Args), gNoiseVec3Args,
                             noiseCode.c_str(), &noiseFuncName);
     const char* noiseVecIni = "noiseVecIni";
     const char* factors     = "factors";
     const char* sum         = "sum";
     const char* xOffsets    = "xOffsets";
     const char* yOffsets    = "yOffsets";
     const char* channel     = "channel";
     // Fill with some prime numbers
     builder->fsCodeAppendf("\t\tconst vec4 %s = vec4(13.0, 53.0, 101.0, 151.0);\n", xOffsets);
     builder->fsCodeAppendf("\t\tconst vec4 %s = vec4(109.0, 167.0, 23.0, 67.0);\n", yOffsets);
     // There are rounding errors if the floor operation is not performed here
     builder->fsCodeAppendf(
         "\t\tvec3 %s = vec3(floor((%s*vec3(%s, 1.0)).xy) * vec2(0.66) * %s, 0.0);\n",
         noiseVecIni, invMatrixUni, vCoords.c_str(), baseFrequencyUni);
     // Perturb the texcoords with three components of noise
     builder->fsCodeAppendf("\t\t%s += 0.1 * vec3(%s(%s + vec3(  0.0,   0.0, %s)),"
                                                 "%s(%s + vec3( 43.0,  17.0, %s)),"
                                                 "%s(%s + vec3(-17.0, -43.0, %s)));\n",
                            noiseVecIni, noiseFuncName.c_str(), noiseVecIni, seedUni,
                                         noiseFuncName.c_str(), noiseVecIni, seedUni,
                                         noiseFuncName.c_str(), noiseVecIni, seedUni);
     builder->fsCodeAppendf("\t\t%s = vec4(0.0);\n", outputColor);
     builder->fsCodeAppendf("\t\tvec3 %s = vec3(1.0);\n", factors);
     builder->fsCodeAppendf("\t\tfloat %s = 0.0;\n", sum);
     // Loop over all octaves
     builder->fsCodeAppendf("\t\tfor (int octave = 0; octave < %d; ++octave) {\n", fNumOctaves);
     // Loop over the 4 channels
     builder->fsCodeAppendf("\t\t\tfor (int %s = 3; %s >= 0; --%s) {\n", channel, channel, channel);
     builder->fsCodeAppendf(
         "\t\t\t\t%s[channel] += %s.x * %s(%s * %s.yyy - vec3(%s[%s], %s[%s], %s * %s.z));\n",
         outputColor, factors, noiseFuncName.c_str(), noiseVecIni, factors, xOffsets, channel,
         yOffsets, channel, seedUni, factors);
     builder->fsCodeAppend("\t\t\t}\n"); // end of the for loop on channels
     builder->fsCodeAppendf("\t\t\t%s += %s.x;\n", sum, factors);
     builder->fsCodeAppendf("\t\t\t%s *= vec3(0.5, 2.0, 0.75);\n", factors);
     builder->fsCodeAppend("\t\t}\n"); // end of the for loop on octaves
     if (fType == SkPerlinNoiseShader::kFractalNoise_Type) {
         // The value of turbulenceFunctionResult comes from ((turbulenceFunctionResult) + 1) / 2
         // by fractalNoise and (turbulenceFunctionResult) by turbulence.
         builder->fsCodeAppendf("\t\t%s = %s * vec4(0.5 / %s) + vec4(0.5);\n",
                                outputColor, outputColor, sum);
     } else {
         builder->fsCodeAppendf("\t\t%s = abs(%s / vec4(%s));\n",
                                outputColor, outputColor, sum);
     }
     builder->fsCodeAppendf("\t\t%s.a *= %s;\n", outputColor, alphaUni);
     // Clamp values
     builder->fsCodeAppendf("\t\t%s = clamp(%s, 0.0, 1.0);\n", outputColor, outputColor);
     // Pre-multiply the result
     builder->fsCodeAppendf("\t\t%s = vec4(%s.rgb * %s.aaa, %s.a);\n",
                            outputColor, outputColor, outputColor, outputColor);
 }
 void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder,
                                const GrDrawEffect&,
                                EffectKey key,
                                const char* outputColor,
                                const char* inputColor,
                                const TransformedCoordsArray& coords,
                                const TextureSamplerArray& samplers) {
     sk_ignore_unused_variable(inputColor);
     SkString vCoords = builder->ensureFSCoords2D(coords, 0);
     fInvMatrixUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                         kMat33f_GrSLType, "invMatrix");
     const char* invMatrixUni = builder->getUniformCStr(fInvMatrixUni);
     fBaseFrequencyUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                             kVec2f_GrSLType, "baseFrequency");
     const char* baseFrequencyUni = builder->getUniformCStr(fBaseFrequencyUni);
     fAlphaUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                     kFloat_GrSLType, "alpha");
     const char* alphaUni = builder->getUniformCStr(fAlphaUni);
     const char* stitchDataUni = NULL;
     if (fStitchTiles) {
         fStitchDataUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                              kVec2f_GrSLType, "stitchData");
         stitchDataUni = builder->getUniformCStr(fStitchDataUni);
     }
     // There are 4 lines, so the center of each line is 1/8, 3/8, 5/8 and 7/8
     const char* chanCoordR  = "0.125";
     const char* chanCoordG  = "0.375";
     const char* chanCoordB  = "0.625";
     const char* chanCoordA  = "0.875";
     const char* chanCoord   = "chanCoord";
     const char* stitchData  = "stitchData";
     const char* ratio       = "ratio";
     const char* noiseXY     = "noiseXY";
     const char* noiseVec    = "noiseVec";
     const char* noiseSmooth = "noiseSmooth";
     const char* fractVal    = "fractVal";
     const char* uv          = "uv";
     const char* ab          = "ab";
     const char* latticeIdx  = "latticeIdx";
     const char* lattice     = "lattice";
     const char* inc8bit     = "0.00390625";  // 1.0 / 256.0
     // This is the math to convert the two 16bit integer packed into rgba 8 bit input into a
     // [-1,1] vector and perform a dot product between that vector and the provided vector.
     const char* dotLattice  = "dot(((%s.ga + %s.rb * vec2(%s)) * vec2(2.0) - vec2(1.0)), %s);";
     // Add noise function
     static const GrGLShaderVar gPerlinNoiseArgs[] =  {
         GrGLShaderVar(chanCoord, kFloat_GrSLType),
         GrGLShaderVar(noiseVec, kVec2f_GrSLType)
     };
     static const GrGLShaderVar gPerlinNoiseStitchArgs[] =  {
         GrGLShaderVar(chanCoord, kFloat_GrSLType),
         GrGLShaderVar(noiseVec, kVec2f_GrSLType),
         GrGLShaderVar(stitchData, kVec2f_GrSLType)
     };
     SkString noiseCode;
     noiseCode.appendf("\tvec4 %s = vec4(floor(%s), fract(%s));", noiseXY, noiseVec, noiseVec);
     // smooth curve : t * t * (3 - 2 * t)
     noiseCode.appendf("\n\tvec2 %s = %s.zw * %s.zw * (vec2(3.0) - vec2(2.0) * %s.zw);",
         noiseSmooth, noiseXY, noiseXY, noiseXY);
     // Adjust frequencies if we're stitching tiles
     if (fStitchTiles) {
         noiseCode.appendf("\n\tif(%s.x >= %s.x) { %s.x -= %s.x; }",
             noiseXY, stitchData, noiseXY, stitchData);
         noiseCode.appendf("\n\tif(%s.x >= (%s.x - 1.0)) { %s.x -= (%s.x - 1.0); }",
             noiseXY, stitchData, noiseXY, stitchData);
         noiseCode.appendf("\n\tif(%s.y >= %s.y) { %s.y -= %s.y; }",
             noiseXY, stitchData, noiseXY, stitchData);
         noiseCode.appendf("\n\tif(%s.y >= (%s.y - 1.0)) { %s.y -= (%s.y - 1.0); }",
             noiseXY, stitchData, noiseXY, stitchData);
     }
     // Get texture coordinates and normalize
     noiseCode.appendf("\n\t%s.xy = fract(floor(mod(%s.xy, 256.0)) / vec2(256.0));\n",
         noiseXY, noiseXY);
     // Get permutation for x
     {
         SkString xCoords("");
         xCoords.appendf("vec2(%s.x, 0.5)", noiseXY);
         noiseCode.appendf("\n\tvec2 %s;\n\t%s.x = ", latticeIdx, latticeIdx);
         builder->appendTextureLookup(&noiseCode, samplers[0], xCoords.c_str(), kVec2f_GrSLType);
         noiseCode.append(".r;");
     }
     // Get permutation for x + 1
     {
         SkString xCoords("");
         xCoords.appendf("vec2(fract(%s.x + %s), 0.5)", noiseXY, inc8bit);
         noiseCode.appendf("\n\t%s.y = ", latticeIdx);
         builder->appendTextureLookup(&noiseCode, samplers[0], xCoords.c_str(), kVec2f_GrSLType);
         noiseCode.append(".r;");
     }
 #if defined(SK_BUILD_FOR_ANDROID)
     // Android rounding for Tegra devices, like, for example: Xoom (Tegra 2), Nexus 7 (Tegra 3).
     // The issue is that colors aren't accurate enough on Tegra devices. For example, if an 8 bit
     // value of 124 (or 0.486275 here) is entered, we can get a texture value of 123.513725
     // (or 0.484368 here). The following rounding operation prevents these precision issues from
     // affecting the result of the noise by making sure that we only have multiples of 1/255.
     // (Note that 1/255 is about 0.003921569, which is the value used here).
     noiseCode.appendf("\n\t%s = floor(%s * vec2(255.0) + vec2(0.5)) * vec2(0.003921569);",
                       latticeIdx, latticeIdx);
 #endif
     // Get (x,y) coordinates with the permutated x
     noiseCode.appendf("\n\t%s = fract(%s + %s.yy);", latticeIdx, latticeIdx, noiseXY);
     noiseCode.appendf("\n\tvec2 %s = %s.zw;", fractVal, noiseXY);
     noiseCode.appendf("\n\n\tvec2 %s;", uv);
     // Compute u, at offset (0,0)
     {
         SkString latticeCoords("");
         latticeCoords.appendf("vec2(%s.x, %s)", latticeIdx, chanCoord);
         noiseCode.appendf("\n\tvec4 %s = ", lattice);
         builder->appendTextureLookup(&noiseCode, samplers[1], latticeCoords.c_str(),
             kVec2f_GrSLType);
         noiseCode.appendf(".bgra;\n\t%s.x = ", uv);
         noiseCode.appendf(dotLattice, lattice, lattice, inc8bit, fractVal);
     }
     noiseCode.appendf("\n\t%s.x -= 1.0;", fractVal);
     // Compute v, at offset (-1,0)
     {
         SkString latticeCoords("");
         latticeCoords.appendf("vec2(%s.y, %s)", latticeIdx, chanCoord);
         noiseCode.append("\n\tlattice = ");
         builder->appendTextureLookup(&noiseCode, samplers[1], latticeCoords.c_str(),
             kVec2f_GrSLType);
         noiseCode.appendf(".bgra;\n\t%s.y = ", uv);
         noiseCode.appendf(dotLattice, lattice, lattice, inc8bit, fractVal);
     }
     // Compute 'a' as a linear interpolation of 'u' and 'v'
     noiseCode.appendf("\n\tvec2 %s;", ab);
     noiseCode.appendf("\n\t%s.x = mix(%s.x, %s.y, %s.x);", ab, uv, uv, noiseSmooth);
     noiseCode.appendf("\n\t%s.y -= 1.0;", fractVal);
     // Compute v, at offset (-1,-1)
     {
         SkString latticeCoords("");
         latticeCoords.appendf("vec2(fract(%s.y + %s), %s)", latticeIdx, inc8bit, chanCoord);
         noiseCode.append("\n\tlattice = ");
         builder->appendTextureLookup(&noiseCode, samplers[1], latticeCoords.c_str(),
             kVec2f_GrSLType);
         noiseCode.appendf(".bgra;\n\t%s.y = ", uv);
         noiseCode.appendf(dotLattice, lattice, lattice, inc8bit, fractVal);
     }
     noiseCode.appendf("\n\t%s.x += 1.0;", fractVal);
     // Compute u, at offset (0,-1)
     {
         SkString latticeCoords("");
         latticeCoords.appendf("vec2(fract(%s.x + %s), %s)", latticeIdx, inc8bit, chanCoord);
         noiseCode.append("\n\tlattice = ");
         builder->appendTextureLookup(&noiseCode, samplers[1], latticeCoords.c_str(),
             kVec2f_GrSLType);
         noiseCode.appendf(".bgra;\n\t%s.x = ", uv);
         noiseCode.appendf(dotLattice, lattice, lattice, inc8bit, fractVal);
     }
     // Compute 'b' as a linear interpolation of 'u' and 'v'
     noiseCode.appendf("\n\t%s.y = mix(%s.x, %s.y, %s.x);", ab, uv, uv, noiseSmooth);
     // Compute the noise as a linear interpolation of 'a' and 'b'
     noiseCode.appendf("\n\treturn mix(%s.x, %s.y, %s.y);\n", ab, ab, noiseSmooth);
     SkString noiseFuncName;
     if (fStitchTiles) {
         builder->fsEmitFunction(kFloat_GrSLType,
                                 "perlinnoise", SK_ARRAY_COUNT(gPerlinNoiseStitchArgs),
                                 gPerlinNoiseStitchArgs, noiseCode.c_str(), &noiseFuncName);
     } else {
         builder->fsEmitFunction(kFloat_GrSLType,
                                 "perlinnoise", SK_ARRAY_COUNT(gPerlinNoiseArgs),
                                 gPerlinNoiseArgs, noiseCode.c_str(), &noiseFuncName);
     }
     // There are rounding errors if the floor operation is not performed here
     builder->fsCodeAppendf("\n\t\tvec2 %s = floor((%s * vec3(%s, 1.0)).xy) * %s;",
                            noiseVec, invMatrixUni, vCoords.c_str(), baseFrequencyUni);
     // Clear the color accumulator
     builder->fsCodeAppendf("\n\t\t%s = vec4(0.0);", outputColor);
     if (fStitchTiles) {
         // Set up TurbulenceInitial stitch values.
         builder->fsCodeAppendf("\n\t\tvec2 %s = %s;", stitchData, stitchDataUni);
     }
     builder->fsCodeAppendf("\n\t\tfloat %s = 1.0;", ratio);
     // Loop over all octaves
     builder->fsCodeAppendf("\n\t\tfor (int octave = 0; octave < %d; ++octave) {", fNumOctaves);
     builder->fsCodeAppendf("\n\t\t\t%s += ", outputColor);
     if (fType != SkPerlinNoiseShader::kFractalNoise_Type) {
         builder->fsCodeAppend("abs(");
     }
     if (fStitchTiles) {
         builder->fsCodeAppendf(
             "vec4(\n\t\t\t\t%s(%s, %s, %s),\n\t\t\t\t%s(%s, %s, %s),"
                  "\n\t\t\t\t%s(%s, %s, %s),\n\t\t\t\t%s(%s, %s, %s))",
             noiseFuncName.c_str(), chanCoordR, noiseVec, stitchData,
             noiseFuncName.c_str(), chanCoordG, noiseVec, stitchData,
             noiseFuncName.c_str(), chanCoordB, noiseVec, stitchData,
             noiseFuncName.c_str(), chanCoordA, noiseVec, stitchData);
     } else {
         builder->fsCodeAppendf(
             "vec4(\n\t\t\t\t%s(%s, %s),\n\t\t\t\t%s(%s, %s),"
                  "\n\t\t\t\t%s(%s, %s),\n\t\t\t\t%s(%s, %s))",
             noiseFuncName.c_str(), chanCoordR, noiseVec,
             noiseFuncName.c_str(), chanCoordG, noiseVec,
             noiseFuncName.c_str(), chanCoordB, noiseVec,
             noiseFuncName.c_str(), chanCoordA, noiseVec);
     }
     if (fType != SkPerlinNoiseShader::kFractalNoise_Type) {
         builder->fsCodeAppendf(")"); // end of "abs("
     }
     builder->fsCodeAppendf(" * %s;", ratio);
     builder->fsCodeAppendf("\n\t\t\t%s *= vec2(2.0);", noiseVec);
     builder->fsCodeAppendf("\n\t\t\t%s *= 0.5;", ratio);
     if (fStitchTiles) {
         builder->fsCodeAppendf("\n\t\t\t%s *= vec2(2.0);", stitchData);
     }
     builder->fsCodeAppend("\n\t\t}"); // end of the for loop on octaves
     if (fType == SkPerlinNoiseShader::kFractalNoise_Type) {
         // The value of turbulenceFunctionResult comes from ((turbulenceFunctionResult) + 1) / 2
         // by fractalNoise and (turbulenceFunctionResult) by turbulence.
         builder->fsCodeAppendf("\n\t\t%s = %s * vec4(0.5) + vec4(0.5);", outputColor, outputColor);
     }
     builder->fsCodeAppendf("\n\t\t%s.a *= %s;", outputColor, alphaUni);
     // Clamp values
     builder->fsCodeAppendf("\n\t\t%s = clamp(%s, 0.0, 1.0);", outputColor, outputColor);
     // Pre-multiply the result
     builder->fsCodeAppendf("\n\t\t%s = vec4(%s.rgb * %s.aaa, %s.a);\n",
                   outputColor, outputColor, outputColor, outputColor);
 }
 GrGLNoise::GrGLNoise(const GrBackendEffectFactory& factory, const GrDrawEffect& drawEffect)
   : INHERITED (factory)
   , fType(drawEffect.castEffect<GrPerlinNoiseEffect>().type())
   , fStitchTiles(drawEffect.castEffect<GrPerlinNoiseEffect>().stitchTiles())
   , fNumOctaves(drawEffect.castEffect<GrPerlinNoiseEffect>().numOctaves()) {
 }
 GrGLEffect::EffectKey GrGLNoise::GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
     const GrPerlinNoiseEffect& turbulence = drawEffect.castEffect<GrPerlinNoiseEffect>();
     EffectKey key = turbulence.numOctaves();
     key = key << 3; // Make room for next 3 bits
     switch (turbulence.type()) {
         case SkPerlinNoiseShader::kFractalNoise_Type:
             key |= 0x1;
             break;
         case SkPerlinNoiseShader::kTurbulence_Type:
             key |= 0x2;
             break;
         default:
             // leave key at 0
             break;
     }
     if (turbulence.stitchTiles()) {
         key |= 0x4; // Flip the 3rd bit if tile stitching is on
     }
     return key;
 }
 void GrGLNoise::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) {
     const GrPerlinNoiseEffect& turbulence = drawEffect.castEffect<GrPerlinNoiseEffect>();
     const SkVector& baseFrequency = turbulence.baseFrequency();
     uman.set2f(fBaseFrequencyUni, baseFrequency.fX, baseFrequency.fY);
     uman.set1f(fAlphaUni, SkScalarDiv(SkIntToScalar(turbulence.alpha()), SkIntToScalar(255)));
     SkMatrix m = turbulence.matrix();
     m.postTranslate(-SK_Scalar1, -SK_Scalar1);
     SkMatrix invM;
     if (!m.invert(&invM)) {
         invM.reset();
     } else {
         invM.postConcat(invM); // Square the matrix
     }
     uman.setSkMatrix(fInvMatrixUni, invM);
 }
 void GrGLPerlinNoise::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) {
     INHERITED::setData(uman, drawEffect);
     const GrPerlinNoiseEffect& turbulence = drawEffect.castEffect<GrPerlinNoiseEffect>();
     if (turbulence.stitchTiles()) {
         const SkPerlinNoiseShader::StitchData& stitchData = turbulence.stitchData();
         uman.set2f(fStitchDataUni, SkIntToScalar(stitchData.fWidth),
                                    SkIntToScalar(stitchData.fHeight));
     }
 }
 void GrGLSimplexNoise::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) {
     INHERITED::setData(uman, drawEffect);
     const GrSimplexNoiseEffect& turbulence = drawEffect.castEffect<GrSimplexNoiseEffect>();
     uman.set1f(fSeedUni, turbulence.seed());
 }
 /////////////////////////////////////////////////////////////////////
 GrEffectRef* SkPerlinNoiseShader::asNewEffect(GrContext* context, const SkPaint& paint) const {
     SkASSERT(NULL != context);
     if (0 == fNumOctaves) {
         SkColor clearColor = 0;
         if (kFractalNoise_Type == fType) {
             clearColor = SkColorSetARGB(paint.getAlpha() / 2, 127, 127, 127);
         }
         SkAutoTUnref<SkColorFilter> cf(SkColorFilter::CreateModeFilter(
                                                 clearColor, SkXfermode::kSrc_Mode));
         return cf->asNewEffect(context);
     }
     // Either we don't stitch tiles, either we have a valid tile size
     SkASSERT(!fStitchTiles || !fTileSize.isEmpty());
 #ifdef SK_USE_SIMPLEX_NOISE
     // Simplex noise is currently disabled but can be enabled by defining SK_USE_SIMPLEX_NOISE
     sk_ignore_unused_variable(context);
     GrEffectRef* effect =
         GrSimplexNoiseEffect::Create(fType, fPaintingData->fBaseFrequency,
                                      fNumOctaves, fStitchTiles, fSeed,
                                      this->getLocalMatrix(), paint.getAlpha());
 #else
     GrTexture* permutationsTexture = GrLockAndRefCachedBitmapTexture(
         context, fPaintingData->getPermutationsBitmap(), NULL);
     GrTexture* noiseTexture = GrLockAndRefCachedBitmapTexture(
         context, fPaintingData->getNoiseBitmap(), NULL);
     GrEffectRef* effect = (NULL != permutationsTexture) && (NULL != noiseTexture) ?
         GrPerlinNoiseEffect::Create(fType, fPaintingData->fBaseFrequency,
                                     fNumOctaves, fStitchTiles,
                                     fPaintingData->fStitchDataInit,
                                     permutationsTexture, noiseTexture,
                                     this->getLocalMatrix(), paint.getAlpha()) :
         NULL;
     // Unlock immediately, this is not great, but we don't have a way of
     // knowing when else to unlock it currently. TODO: Remove this when
     // unref becomes the unlock replacement for all types of textures.
     if (NULL != permutationsTexture) {
         GrUnlockAndUnrefCachedBitmapTexture(permutationsTexture);
     }
     if (NULL != noiseTexture) {
         GrUnlockAndUnrefCachedBitmapTexture(noiseTexture);
     }
 #endif
     return effect;
 }
 #else
 GrEffectRef* SkPerlinNoiseShader::asNewEffect(GrContext*, const SkPaint&) const {
     SkDEBUGFAIL("Should not call in GPU-less build");
     return NULL;
 }
 #endif
 #ifndef SK_IGNORE_TO_STRING
 void SkPerlinNoiseShader::toString(SkString* str) const {
     str->append("SkPerlinNoiseShader: (");
     str->append("type: ");
     switch (fType) {
         case kFractalNoise_Type:
             str->append("\"fractal noise\"");
             break;
         case kTurbulence_Type:
             str->append("\"turbulence\"");
             break;
         default:
             str->append("\"unknown\"");
             break;
     }
     str->append(" base frequency: (");
     str->appendScalar(fBaseFrequencyX);
     str->append(", ");
     str->appendScalar(fBaseFrequencyY);
     str->append(") number of octaves: ");
     str->appendS32(fNumOctaves);
     str->append(" seed: ");
     str->appendScalar(fSeed);
     str->append(" stitch tiles: ");
     str->append(fStitchTiles ? "true " : "false ");
     this->INHERITED::toString(str);
     str->append(")");
 }
 #endif

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gfx/skia/trunk/src/effects/SkPerlinNoiseShader.cpp@6474c204b198 (annotated)

gfx/skia/trunk/src/effects/SkPerlinNoiseShader.cpp