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skia2/src/effects/SkPerlinNoiseShader.cpp

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/*
* 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 "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 "GrInvariantOutput.h"
#include "SkGr.h"
#include "effects/GrConstColorProcessor.h"
#include "glsl/GrGLSLFragmentProcessor.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"
#include "glsl/GrGLSLProgramDataManager.h"
#include "glsl/GrGLSLUniformHandler.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;
}
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);
}
} // 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,
const SkMatrix& matrix)
{
SkVector vec[2] = {
{ SkScalarInvert(baseFrequencyX), SkScalarInvert(baseFrequencyY) },
{ SkIntToScalar(tileSize.fWidth), SkIntToScalar(tileSize.fHeight) },
};
matrix.mapVectors(vec, 2);
fBaseFrequency.set(SkScalarInvert(vec[0].fX), SkScalarInvert(vec[0].fY));
fTileSize.set(SkScalarRoundToInt(vec[1].fX), SkScalarRoundToInt(vec[1].fY));
this->init(seed);
if (!fTileSize.isEmpty()) {
this->stitch();
}
#if SK_SUPPORT_GPU
fPermutationsBitmap.setInfo(SkImageInfo::MakeA8(kBlockSize, 1));
fPermutationsBitmap.setPixels(fLatticeSelector);
fNoiseBitmap.setInfo(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
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 (fBaseFrequency.fX / lowFrequencx < 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 (fBaseFrequency.fY / lowFrequency < 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
const SkBitmap& getPermutationsBitmap() const { return fPermutationsBitmap; }
const SkBitmap& getNoiseBitmap() const { return fNoiseBitmap; }
#endif
};
sk_sp<SkShader> SkPerlinNoiseShader::MakeFractalNoise(SkScalar baseFrequencyX,
SkScalar baseFrequencyY,
int numOctaves, SkScalar seed,
const SkISize* tileSize) {
return sk_sp<SkShader>(new SkPerlinNoiseShader(kFractalNoise_Type, baseFrequencyX,
baseFrequencyY, numOctaves,
seed, tileSize));
}
sk_sp<SkShader> SkPerlinNoiseShader::MakeTurbulence(SkScalar baseFrequencyX,
SkScalar baseFrequencyY,
int numOctaves, SkScalar seed,
const SkISize* tileSize) {
return sk_sp<SkShader>(new 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(nullptr == tileSize ? SkISize::Make(0, 0) : *tileSize)
, fStitchTiles(!fTileSize.isEmpty())
{
SkASSERT(numOctaves >= 0 && numOctaves < 256);
}
SkPerlinNoiseShader::~SkPerlinNoiseShader() {
}
sk_sp<SkFlattenable> SkPerlinNoiseShader::CreateProc(SkReadBuffer& buffer) {
Type type = (Type)buffer.readInt();
SkScalar freqX = buffer.readScalar();
SkScalar freqY = buffer.readScalar();
int octaves = buffer.readInt();
SkScalar seed = buffer.readScalar();
SkISize tileSize;
tileSize.fWidth = buffer.readInt();
tileSize.fHeight = buffer.readInt();
switch (type) {
case kFractalNoise_Type:
return SkPerlinNoiseShader::MakeFractalNoise(freqX, freqY, octaves, seed,
&tileSize);
case kTurbulence_Type:
return SkPerlinNoiseShader::MakeTurbulence(freqX, freqY, octaves, seed,
&tileSize);
default:
return nullptr;
}
}
void SkPerlinNoiseShader::flatten(SkWriteBuffer& buffer) const {
buffer.writeInt((int) fType);
buffer.writeScalar(fBaseFrequencyX);
buffer.writeScalar(fBaseFrequencyY);
buffer.writeInt(fNumOctaves);
buffer.writeScalar(fSeed);
buffer.writeInt(fTileSize.fWidth);
buffer.writeInt(fTileSize.fHeight);
}
SkScalar SkPerlinNoiseShader::PerlinNoiseShaderContext::noise2D(
int channel, const StitchData& stitchData, const SkPoint& noiseVector) const {
struct Noise {
int noisePositionIntegerValue;
int nextNoisePositionIntegerValue;
SkScalar noisePositionFractionValue;
Noise(SkScalar component)
{
SkScalar position = component + kPerlinNoise;
noisePositionIntegerValue = SkScalarFloorToInt(position);
noisePositionFractionValue = position - SkIntToScalar(noisePositionIntegerValue);
nextNoisePositionIntegerValue = noisePositionIntegerValue + 1;
}
};
Noise noiseX(noiseVector.x());
Noise noiseY(noiseVector.y());
SkScalar u, v;
const SkPerlinNoiseShader& perlinNoiseShader = static_cast<const SkPerlinNoiseShader&>(fShader);
// If stitching, adjust lattice points accordingly.
if (perlinNoiseShader.fStitchTiles) {
noiseX.noisePositionIntegerValue =
checkNoise(noiseX.noisePositionIntegerValue, stitchData.fWrapX, stitchData.fWidth);
noiseY.noisePositionIntegerValue =
checkNoise(noiseY.noisePositionIntegerValue, stitchData.fWrapY, stitchData.fHeight);
noiseX.nextNoisePositionIntegerValue =
checkNoise(noiseX.nextNoisePositionIntegerValue, stitchData.fWrapX, stitchData.fWidth);
noiseY.nextNoisePositionIntegerValue =
checkNoise(noiseY.nextNoisePositionIntegerValue, stitchData.fWrapY, stitchData.fHeight);
}
noiseX.noisePositionIntegerValue &= kBlockMask;
noiseY.noisePositionIntegerValue &= kBlockMask;
noiseX.nextNoisePositionIntegerValue &= kBlockMask;
noiseY.nextNoisePositionIntegerValue &= kBlockMask;
int i =
fPaintingData->fLatticeSelector[noiseX.noisePositionIntegerValue];
int j =
fPaintingData->fLatticeSelector[noiseX.nextNoisePositionIntegerValue];
int b00 = (i + noiseY.noisePositionIntegerValue) & kBlockMask;
int b10 = (j + noiseY.noisePositionIntegerValue) & kBlockMask;
int b01 = (i + noiseY.nextNoisePositionIntegerValue) & kBlockMask;
int b11 = (j + noiseY.nextNoisePositionIntegerValue) & kBlockMask;
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 = fPaintingData->fGradient[channel][b00].dot(fractionValue);
fractionValue.fX -= SK_Scalar1; // Offset (-1,0)
v = fPaintingData->fGradient[channel][b10].dot(fractionValue);
SkScalar a = SkScalarInterp(u, v, sx);
fractionValue.fY -= SK_Scalar1; // Offset (-1,-1)
v = fPaintingData->fGradient[channel][b11].dot(fractionValue);
fractionValue.fX = noiseX.noisePositionFractionValue; // Offset (0,-1)
u = fPaintingData->fGradient[channel][b01].dot(fractionValue);
SkScalar b = SkScalarInterp(u, v, sx);
return SkScalarInterp(a, b, sy);
}
SkScalar SkPerlinNoiseShader::PerlinNoiseShaderContext::calculateTurbulenceValueForPoint(
int channel, StitchData& stitchData, const SkPoint& point) const {
const SkPerlinNoiseShader& perlinNoiseShader = static_cast<const SkPerlinNoiseShader&>(fShader);
if (perlinNoiseShader.fStitchTiles) {
// Set up TurbulenceInitial stitch values.
stitchData = fPaintingData->fStitchDataInit;
}
SkScalar turbulenceFunctionResult = 0;
SkPoint noiseVector(SkPoint::Make(SkScalarMul(point.x(), fPaintingData->fBaseFrequency.fX),
SkScalarMul(point.y(), fPaintingData->fBaseFrequency.fY)));
SkScalar ratio = SK_Scalar1;
for (int octave = 0; octave < perlinNoiseShader.fNumOctaves; ++octave) {
SkScalar noise = noise2D(channel, stitchData, noiseVector);
SkScalar numer = (perlinNoiseShader.fType == kFractalNoise_Type) ?
noise : SkScalarAbs(noise);
turbulenceFunctionResult += numer / ratio;
noiseVector.fX *= 2;
noiseVector.fY *= 2;
ratio *= 2;
if (perlinNoiseShader.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 (perlinNoiseShader.fType == kFractalNoise_Type) {
turbulenceFunctionResult =
SkScalarMul(turbulenceFunctionResult, SK_ScalarHalf) + SK_ScalarHalf;
}
if (channel == 3) { // Scale alpha by paint value
turbulenceFunctionResult *= SkIntToScalar(getPaintAlpha()) / 255;
}
// Clamp result
return SkScalarPin(turbulenceFunctionResult, 0, SK_Scalar1);
}
SkPMColor SkPerlinNoiseShader::PerlinNoiseShaderContext::shade(
const SkPoint& point, StitchData& stitchData) const {
SkPoint newPoint;
fMatrix.mapPoints(&newPoint, &point, 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, stitchData, newPoint));
}
return SkPreMultiplyARGB(rgba[3], rgba[0], rgba[1], rgba[2]);
}
SkShader::Context* SkPerlinNoiseShader::onCreateContext(const ContextRec& rec,
void* storage) const {
return new (storage) PerlinNoiseShaderContext(*this, rec);
}
size_t SkPerlinNoiseShader::onContextSize(const ContextRec&) const {
return sizeof(PerlinNoiseShaderContext);
}
SkPerlinNoiseShader::PerlinNoiseShaderContext::PerlinNoiseShaderContext(
const SkPerlinNoiseShader& shader, const ContextRec& rec)
: INHERITED(shader, rec)
{
SkMatrix newMatrix = *rec.fMatrix;
newMatrix.preConcat(shader.getLocalMatrix());
if (rec.fLocalMatrix) {
newMatrix.preConcat(*rec.fLocalMatrix);
}
// 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.
fMatrix.setTranslate(-newMatrix.getTranslateX() + SK_Scalar1, -newMatrix.getTranslateY() + SK_Scalar1);
fPaintingData = new PaintingData(shader.fTileSize, shader.fSeed, shader.fBaseFrequencyX,
shader.fBaseFrequencyY, newMatrix);
}
SkPerlinNoiseShader::PerlinNoiseShaderContext::~PerlinNoiseShaderContext() { delete fPaintingData; }
void SkPerlinNoiseShader::PerlinNoiseShaderContext::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;
}
}
/////////////////////////////////////////////////////////////////////
#if SK_SUPPORT_GPU
class GrGLPerlinNoise : public GrGLSLFragmentProcessor {
public:
void emitCode(EmitArgs&) override;
static inline void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*);
protected:
void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;
private:
GrGLSLProgramDataManager::UniformHandle fStitchDataUni;
GrGLSLProgramDataManager::UniformHandle fBaseFrequencyUni;
typedef GrGLSLFragmentProcessor INHERITED;
};
/////////////////////////////////////////////////////////////////////
class GrPerlinNoiseEffect : public GrFragmentProcessor {
public:
static GrFragmentProcessor* Create(SkPerlinNoiseShader::Type type,
int numOctaves, bool stitchTiles,
SkPerlinNoiseShader::PaintingData* paintingData,
GrTexture* permutationsTexture, GrTexture* noiseTexture,
const SkMatrix& matrix) {
return new GrPerlinNoiseEffect(type, numOctaves, stitchTiles, paintingData,
permutationsTexture, noiseTexture, matrix);
}
virtual ~GrPerlinNoiseEffect() { delete fPaintingData; }
const char* name() const override { return "PerlinNoise"; }
const SkPerlinNoiseShader::StitchData& stitchData() const { return fPaintingData->fStitchDataInit; }
SkPerlinNoiseShader::Type type() const { return fType; }
bool stitchTiles() const { return fStitchTiles; }
const SkVector& baseFrequency() const { return fPaintingData->fBaseFrequency; }
int numOctaves() const { return fNumOctaves; }
const SkMatrix& matrix() const { return fCoordTransform.getMatrix(); }
private:
GrGLSLFragmentProcessor* onCreateGLSLInstance() const override {
return new GrGLPerlinNoise;
}
virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
GrProcessorKeyBuilder* b) const override {
GrGLPerlinNoise::GenKey(*this, caps, b);
}
bool onIsEqual(const GrFragmentProcessor& sBase) const override {
const GrPerlinNoiseEffect& s = sBase.cast<GrPerlinNoiseEffect>();
return fType == s.fType &&
fPaintingData->fBaseFrequency == s.fPaintingData->fBaseFrequency &&
fNumOctaves == s.fNumOctaves &&
fStitchTiles == s.fStitchTiles &&
fPaintingData->fStitchDataInit == s.fPaintingData->fStitchDataInit;
}
void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
inout->setToUnknown(GrInvariantOutput::kWillNot_ReadInput);
}
GrPerlinNoiseEffect(SkPerlinNoiseShader::Type type,
int numOctaves, bool stitchTiles,
SkPerlinNoiseShader::PaintingData* paintingData,
GrTexture* permutationsTexture, GrTexture* noiseTexture,
const SkMatrix& matrix)
: fType(type)
, fNumOctaves(numOctaves)
, fStitchTiles(stitchTiles)
, fPermutationsAccess(permutationsTexture)
, fNoiseAccess(noiseTexture)
, fPaintingData(paintingData) {
this->initClassID<GrPerlinNoiseEffect>();
this->addTextureAccess(&fPermutationsAccess);
this->addTextureAccess(&fNoiseAccess);
fCoordTransform.reset(kLocal_GrCoordSet, matrix);
this->addCoordTransform(&fCoordTransform);
}
GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
SkPerlinNoiseShader::Type fType;
GrCoordTransform fCoordTransform;
int fNumOctaves;
bool fStitchTiles;
GrTextureAccess fPermutationsAccess;
GrTextureAccess fNoiseAccess;
SkPerlinNoiseShader::PaintingData *fPaintingData;
private:
typedef GrFragmentProcessor INHERITED;
};
/////////////////////////////////////////////////////////////////////
GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrPerlinNoiseEffect);
const GrFragmentProcessor* GrPerlinNoiseEffect::TestCreate(GrProcessorTestData* d) {
int numOctaves = d->fRandom->nextRangeU(2, 10);
bool stitchTiles = d->fRandom->nextBool();
SkScalar seed = SkIntToScalar(d->fRandom->nextU());
SkISize tileSize = SkISize::Make(d->fRandom->nextRangeU(4, 4096),
d->fRandom->nextRangeU(4, 4096));
SkScalar baseFrequencyX = d->fRandom->nextRangeScalar(0.01f,
0.99f);
SkScalar baseFrequencyY = d->fRandom->nextRangeScalar(0.01f,
0.99f);
sk_sp<SkShader> shader(d->fRandom->nextBool() ?
SkPerlinNoiseShader::MakeFractalNoise(baseFrequencyX, baseFrequencyY, numOctaves, seed,
stitchTiles ? &tileSize : nullptr) :
SkPerlinNoiseShader::MakeTurbulence(baseFrequencyX, baseFrequencyY, numOctaves, seed,
stitchTiles ? &tileSize : nullptr));
return shader->asFragmentProcessor(d->fContext,
GrTest::TestMatrix(d->fRandom), nullptr,
kNone_SkFilterQuality);
}
void GrGLPerlinNoise::emitCode(EmitArgs& args) {
const GrPerlinNoiseEffect& pne = args.fFp.cast<GrPerlinNoiseEffect>();
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
SkString vCoords = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
fBaseFrequencyUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"baseFrequency");
const char* baseFrequencyUni = uniformHandler->getUniformCStr(fBaseFrequencyUni);
const char* stitchDataUni = nullptr;
if (pne.stitchTiles()) {
fStitchDataUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"stitchData");
stitchDataUni = uniformHandler->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* noiseVec = "noiseVec";
const char* noiseSmooth = "noiseSmooth";
const char* floorVal = "floorVal";
const char* fractVal = "fractVal";
const char* uv = "uv";
const char* ab = "ab";
const char* latticeIdx = "latticeIdx";
const char* bcoords = "bcoords";
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 GrGLSLShaderVar gPerlinNoiseArgs[] = {
GrGLSLShaderVar(chanCoord, kFloat_GrSLType),
GrGLSLShaderVar(noiseVec, kVec2f_GrSLType)
};
static const GrGLSLShaderVar gPerlinNoiseStitchArgs[] = {
GrGLSLShaderVar(chanCoord, kFloat_GrSLType),
GrGLSLShaderVar(noiseVec, kVec2f_GrSLType),
GrGLSLShaderVar(stitchData, kVec2f_GrSLType)
};
SkString noiseCode;
noiseCode.appendf("\tvec4 %s;\n", floorVal);
noiseCode.appendf("\t%s.xy = floor(%s);\n", floorVal, noiseVec);
noiseCode.appendf("\t%s.zw = %s.xy + vec2(1.0);\n", floorVal, floorVal);
noiseCode.appendf("\tvec2 %s = fract(%s);\n", fractVal, noiseVec);
// smooth curve : t * t * (3 - 2 * t)
noiseCode.appendf("\n\tvec2 %s = %s * %s * (vec2(3.0) - vec2(2.0) * %s);",
noiseSmooth, fractVal, fractVal, fractVal);
// Adjust frequencies if we're stitching tiles
if (pne.stitchTiles()) {
noiseCode.appendf("\n\tif(%s.x >= %s.x) { %s.x -= %s.x; }",
floorVal, stitchData, floorVal, stitchData);
noiseCode.appendf("\n\tif(%s.y >= %s.y) { %s.y -= %s.y; }",
floorVal, stitchData, floorVal, stitchData);
noiseCode.appendf("\n\tif(%s.z >= %s.x) { %s.z -= %s.x; }",
floorVal, stitchData, floorVal, stitchData);
noiseCode.appendf("\n\tif(%s.w >= %s.y) { %s.w -= %s.y; }",
floorVal, stitchData, floorVal, stitchData);
}
// Get texture coordinates and normalize
noiseCode.appendf("\n\t%s = fract(floor(mod(%s, 256.0)) / vec4(256.0));\n",
floorVal, floorVal);
// Get permutation for x
{
SkString xCoords("");
xCoords.appendf("vec2(%s.x, 0.5)", floorVal);
noiseCode.appendf("\n\tvec2 %s;\n\t%s.x = ", latticeIdx, latticeIdx);
fragBuilder->appendTextureLookup(&noiseCode, args.fSamplers[0], xCoords.c_str(),
kVec2f_GrSLType);
noiseCode.append(".r;");
}
// Get permutation for x + 1
{
SkString xCoords("");
xCoords.appendf("vec2(%s.z, 0.5)", floorVal);
noiseCode.appendf("\n\t%s.y = ", latticeIdx);
fragBuilder->appendTextureLookup(&noiseCode, args.fSamplers[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\tvec4 %s = fract(%s.xyxy + %s.yyww);", bcoords, latticeIdx, floorVal);
noiseCode.appendf("\n\n\tvec2 %s;", uv);
// Compute u, at offset (0,0)
{
SkString latticeCoords("");
latticeCoords.appendf("vec2(%s.x, %s)", bcoords, chanCoord);
noiseCode.appendf("\n\tvec4 %s = ", lattice);
fragBuilder->appendTextureLookup(&noiseCode, args.fSamplers[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)", bcoords, chanCoord);
noiseCode.append("\n\tlattice = ");
fragBuilder->appendTextureLookup(&noiseCode, args.fSamplers[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(%s.w, %s)", bcoords, chanCoord);
noiseCode.append("\n\tlattice = ");
fragBuilder->appendTextureLookup(&noiseCode, args.fSamplers[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(%s.z, %s)", bcoords, chanCoord);
noiseCode.append("\n\tlattice = ");
fragBuilder->appendTextureLookup(&noiseCode, args.fSamplers[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 (pne.stitchTiles()) {
fragBuilder->emitFunction(kFloat_GrSLType,
"perlinnoise", SK_ARRAY_COUNT(gPerlinNoiseStitchArgs),
gPerlinNoiseStitchArgs, noiseCode.c_str(), &noiseFuncName);
} else {
fragBuilder->emitFunction(kFloat_GrSLType,
"perlinnoise", SK_ARRAY_COUNT(gPerlinNoiseArgs),
gPerlinNoiseArgs, noiseCode.c_str(), &noiseFuncName);
}
// There are rounding errors if the floor operation is not performed here
fragBuilder->codeAppendf("\n\t\tvec2 %s = floor(%s.xy) * %s;",
noiseVec, vCoords.c_str(), baseFrequencyUni);
// Clear the color accumulator
fragBuilder->codeAppendf("\n\t\t%s = vec4(0.0);", args.fOutputColor);
if (pne.stitchTiles()) {
// Set up TurbulenceInitial stitch values.
fragBuilder->codeAppendf("vec2 %s = %s;", stitchData, stitchDataUni);
}
fragBuilder->codeAppendf("float %s = 1.0;", ratio);
// Loop over all octaves
fragBuilder->codeAppendf("for (int octave = 0; octave < %d; ++octave) {", pne.numOctaves());
fragBuilder->codeAppendf("%s += ", args.fOutputColor);
if (pne.type() != SkPerlinNoiseShader::kFractalNoise_Type) {
fragBuilder->codeAppend("abs(");
}
if (pne.stitchTiles()) {
fragBuilder->codeAppendf(
"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 {
fragBuilder->codeAppendf(
"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 (pne.type() != SkPerlinNoiseShader::kFractalNoise_Type) {
fragBuilder->codeAppendf(")"); // end of "abs("
}
fragBuilder->codeAppendf(" * %s;", ratio);
fragBuilder->codeAppendf("\n\t\t\t%s *= vec2(2.0);", noiseVec);
fragBuilder->codeAppendf("\n\t\t\t%s *= 0.5;", ratio);
if (pne.stitchTiles()) {
fragBuilder->codeAppendf("\n\t\t\t%s *= vec2(2.0);", stitchData);
}
fragBuilder->codeAppend("\n\t\t}"); // end of the for loop on octaves
if (pne.type() == SkPerlinNoiseShader::kFractalNoise_Type) {
// The value of turbulenceFunctionResult comes from ((turbulenceFunctionResult) + 1) / 2
// by fractalNoise and (turbulenceFunctionResult) by turbulence.
fragBuilder->codeAppendf("\n\t\t%s = %s * vec4(0.5) + vec4(0.5);",
args.fOutputColor,args.fOutputColor);
}
// Clamp values
fragBuilder->codeAppendf("\n\t\t%s = clamp(%s, 0.0, 1.0);", args.fOutputColor, args.fOutputColor);
// Pre-multiply the result
fragBuilder->codeAppendf("\n\t\t%s = vec4(%s.rgb * %s.aaa, %s.a);\n",
args.fOutputColor, args.fOutputColor,
args.fOutputColor, args.fOutputColor);
}
void GrGLPerlinNoise::GenKey(const GrProcessor& processor, const GrGLSLCaps&,
GrProcessorKeyBuilder* b) {
const GrPerlinNoiseEffect& turbulence = processor.cast<GrPerlinNoiseEffect>();
uint32_t 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
}
b->add32(key);
}
void GrGLPerlinNoise::onSetData(const GrGLSLProgramDataManager& pdman,
const GrProcessor& processor) {
INHERITED::onSetData(pdman, processor);
const GrPerlinNoiseEffect& turbulence = processor.cast<GrPerlinNoiseEffect>();
const SkVector& baseFrequency = turbulence.baseFrequency();
pdman.set2f(fBaseFrequencyUni, baseFrequency.fX, baseFrequency.fY);
if (turbulence.stitchTiles()) {
const SkPerlinNoiseShader::StitchData& stitchData = turbulence.stitchData();
pdman.set2f(fStitchDataUni, SkIntToScalar(stitchData.fWidth),
SkIntToScalar(stitchData.fHeight));
}
}
/////////////////////////////////////////////////////////////////////
const GrFragmentProcessor* SkPerlinNoiseShader::asFragmentProcessor(
GrContext* context,
const SkMatrix& viewM,
const SkMatrix* externalLocalMatrix,
SkFilterQuality) const {
SkASSERT(context);
SkMatrix localMatrix = this->getLocalMatrix();
if (externalLocalMatrix) {
localMatrix.preConcat(*externalLocalMatrix);
}
SkMatrix matrix = viewM;
matrix.preConcat(localMatrix);
if (0 == fNumOctaves) {
if (kFractalNoise_Type == fType) {
// Extract the incoming alpha and emit rgba = (a/4, a/4, a/4, a/2)
SkAutoTUnref<const GrFragmentProcessor> inner(
GrConstColorProcessor::Create(0x80404040,
GrConstColorProcessor::kModulateRGBA_InputMode));
return GrFragmentProcessor::MulOutputByInputAlpha(inner);
}
// Emit zero.
return GrConstColorProcessor::Create(0x0, GrConstColorProcessor::kIgnore_InputMode);
}
// Either we don't stitch tiles, either we have a valid tile size
SkASSERT(!fStitchTiles || !fTileSize.isEmpty());
SkPerlinNoiseShader::PaintingData* paintingData =
new PaintingData(fTileSize, fSeed, fBaseFrequencyX, fBaseFrequencyY, matrix);
SkAutoTUnref<GrTexture> permutationsTexture(
GrRefCachedBitmapTexture(context, paintingData->getPermutationsBitmap(),
GrTextureParams::ClampNoFilter()));
SkAutoTUnref<GrTexture> noiseTexture(
GrRefCachedBitmapTexture(context, paintingData->getNoiseBitmap(),
GrTextureParams::ClampNoFilter()));
SkMatrix m = viewM;
m.setTranslateX(-localMatrix.getTranslateX() + SK_Scalar1);
m.setTranslateY(-localMatrix.getTranslateY() + SK_Scalar1);
if ((permutationsTexture) && (noiseTexture)) {
SkAutoTUnref<GrFragmentProcessor> inner(
GrPerlinNoiseEffect::Create(fType,
fNumOctaves,
fStitchTiles,
paintingData,
permutationsTexture, noiseTexture,
m));
return GrFragmentProcessor::MulOutputByInputAlpha(inner);
}
delete paintingData;
return nullptr;
}
#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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