/*
* 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 "GrDistanceFieldGeoProc.h"
#include "GrTexture.h"
#include "SkDistanceFieldGen.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"
#include "glsl/GrGLSLGeometryProcessor.h"
#include "glsl/GrGLSLProgramDataManager.h"
#include "glsl/GrGLSLUniformHandler.h"
#include "glsl/GrGLSLUtil.h"
#include "glsl/GrGLSLVarying.h"
#include "glsl/GrGLSLVertexShaderBuilder.h"
// Assuming a radius of a little less than the diagonal of the fragment
#define SK_DistanceFieldAAFactor "0.65"
class GrGLDistanceFieldA8TextGeoProc : public GrGLSLGeometryProcessor {
public:
GrGLDistanceFieldA8TextGeoProc()
: fViewMatrix(SkMatrix::InvalidMatrix())
#ifdef SK_GAMMA_APPLY_TO_A8
, fDistanceAdjust(-1.0f)
#endif
{}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldA8TextGeoProc& dfTexEffect =
args.fGP.cast<GrDistanceFieldA8TextGeoProc>();
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(dfTexEffect);
#ifdef SK_GAMMA_APPLY_TO_A8
// adjust based on gamma
const char* distanceAdjustUniName = nullptr;
// width, height, 1/(3*width)
fDistanceAdjustUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kDefault_GrSLPrecision,
"DistanceAdjust", &distanceAdjustUniName);
#endif
// Setup pass through color
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
dfTexEffect.inPosition()->fName,
dfTexEffect.viewMatrix(),
&fViewMatrixUniform);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
dfTexEffect.inPosition()->fName,
args.fFPCoordTransformHandler);
// add varyings
GrGLSLVertToFrag recipScale(kFloat_GrSLType);
GrGLSLVertToFrag uv(kVec2f_GrSLType);
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
bool isGammaCorrect =
SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);
// compute numbers to be hardcoded to convert texture coordinates from float to int
SkASSERT(dfTexEffect.numTextureSamplers() == 1);
GrTexture* atlas = dfTexEffect.textureSampler(0).texture();
SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
GrGLSLVertToFrag st(kVec2f_GrSLType);
varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
atlas->width(), atlas->height(),
dfTexEffect.inTextureCoords()->fName);
// Use highp to work around aliasing issues
fragBuilder->codeAppendf("highp vec2 uv = %s;\n", uv.fsIn());
fragBuilder->codeAppend("\tfloat texColor = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0],
"uv",
kVec2f_GrSLType);
fragBuilder->codeAppend(".r;\n");
fragBuilder->codeAppend("\tfloat distance = "
SK_DistanceFieldMultiplier "*(texColor - " SK_DistanceFieldThreshold ");");
#ifdef SK_GAMMA_APPLY_TO_A8
// adjust width based on gamma
fragBuilder->codeAppendf("distance -= %s;", distanceAdjustUniName);
#endif
fragBuilder->codeAppend("float afwidth;");
if (isUniformScale) {
// For uniform scale, we adjust for the effect of the transformation on the distance
// by using the length of the gradient of the t coordinate in the y direction.
// We use st coordinates to ensure we're mapping 1:1 from texel space to pixel space.
// this gives us a smooth step across approximately one fragment
#ifdef SK_VULKAN
fragBuilder->codeAppendf("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdx(%s.x));",
st.fsIn());
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppendf("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(%s.y));",
st.fsIn());
#endif
} else if (isSimilarity) {
// For similarity transform, we adjust the effect of the transformation on the distance
// by using the length of the gradient of the texture coordinates. We use st coordinates
// to ensure we're mapping 1:1 from texel space to pixel space.
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
// this gives us a smooth step across approximately one fragment
#ifdef SK_VULKAN
fragBuilder->codeAppendf("float st_grad_len = length(dFdx(%s));", st.fsIn());
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppendf("float st_grad_len = length(dFdy(%s));", st.fsIn());
#endif
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*st_grad_len);");
} else {
// For general transforms, to determine the amount of correction we multiply a unit
// vector pointing along the SDF gradient direction by the Jacobian of the st coords
// (which is the inverse transform for this fragment) and take the length of the result.
fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance), dFdy(distance));");
// the length of the gradient may be 0, so we need to check for this
// this also compensates for the Adreno, which likes to drop tiles on division by 0
fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppendf("vec2 Jdx = dFdx(%s);", st.fsIn());
fragBuilder->codeAppendf("vec2 Jdy = dFdy(%s);", st.fsIn());
fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
}
// The smoothstep falloff compensates for the non-linear sRGB response curve. If we are
// doing gamma-correct rendering (to an sRGB or F16 buffer), then we actually want distance
// mapped linearly to coverage, so use a linear step:
if (isGammaCorrect) {
fragBuilder->codeAppend(
"float val = clamp(distance + afwidth / (2.0 * afwidth), 0.0, 1.0);");
} else {
fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
}
fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
}
void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& proc,
FPCoordTransformIter&& transformIter) override {
#ifdef SK_GAMMA_APPLY_TO_A8
const GrDistanceFieldA8TextGeoProc& dfTexEffect = proc.cast<GrDistanceFieldA8TextGeoProc>();
float distanceAdjust = dfTexEffect.getDistanceAdjust();
if (distanceAdjust != fDistanceAdjust) {
pdman.set1f(fDistanceAdjustUni, distanceAdjust);
fDistanceAdjust = distanceAdjust;
}
#endif
const GrDistanceFieldA8TextGeoProc& dfa8gp = proc.cast<GrDistanceFieldA8TextGeoProc>();
if (!dfa8gp.viewMatrix().isIdentity() && !fViewMatrix.cheapEqualTo(dfa8gp.viewMatrix())) {
fViewMatrix = dfa8gp.viewMatrix();
float viewMatrix[3 * 3];
GrGLSLGetMatrix<3>(viewMatrix, fViewMatrix);
pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
}
this->setTransformDataHelper(SkMatrix::I(), pdman, &transformIter);
}
static inline void GenKey(const GrGeometryProcessor& gp,
const GrShaderCaps&,
GrProcessorKeyBuilder* b) {
const GrDistanceFieldA8TextGeoProc& dfTexEffect = gp.cast<GrDistanceFieldA8TextGeoProc>();
uint32_t key = dfTexEffect.getFlags();
key |= ComputePosKey(dfTexEffect.viewMatrix()) << 16;
b->add32(key);
// Currently we hardcode numbers to convert atlas coordinates to normalized floating point
SkASSERT(gp.numTextureSamplers() == 1);
GrTexture* atlas = gp.textureSampler(0).texture();
SkASSERT(atlas);
b->add32(atlas->width());
b->add32(atlas->height());
}
private:
SkMatrix fViewMatrix;
UniformHandle fViewMatrixUniform;
#ifdef SK_GAMMA_APPLY_TO_A8
float fDistanceAdjust;
UniformHandle fDistanceAdjustUni;
#endif
typedef GrGLSLGeometryProcessor INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
GrDistanceFieldA8TextGeoProc::GrDistanceFieldA8TextGeoProc(GrResourceProvider* resourceProvider,
GrColor color,
const SkMatrix& viewMatrix,
sk_sp<GrTextureProxy> proxy,
const GrSamplerParams& params,
#ifdef SK_GAMMA_APPLY_TO_A8
float distanceAdjust,
#endif
uint32_t flags,
bool usesLocalCoords)
: fColor(color)
, fViewMatrix(viewMatrix)
, fTextureSampler(resourceProvider, std::move(proxy), params)
#ifdef SK_GAMMA_APPLY_TO_A8
, fDistanceAdjust(distanceAdjust)
#endif
, fFlags(flags & kNonLCD_DistanceFieldEffectMask)
, fInColor(nullptr)
, fUsesLocalCoords(usesLocalCoords) {
SkASSERT(!(flags & ~kNonLCD_DistanceFieldEffectMask));
this->initClassID<GrDistanceFieldA8TextGeoProc>();
fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
kHigh_GrSLPrecision);
fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
fInTextureCoords = &this->addVertexAttrib("inTextureCoords", kVec2us_GrVertexAttribType,
kHigh_GrSLPrecision);
this->addTextureSampler(&fTextureSampler);
}
void GrDistanceFieldA8TextGeoProc::getGLSLProcessorKey(const GrShaderCaps& caps,
GrProcessorKeyBuilder* b) const {
GrGLDistanceFieldA8TextGeoProc::GenKey(*this, caps, b);
}
GrGLSLPrimitiveProcessor*
GrDistanceFieldA8TextGeoProc::createGLSLInstance(const GrShaderCaps&) const {
return new GrGLDistanceFieldA8TextGeoProc();
}
///////////////////////////////////////////////////////////////////////////////
GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrDistanceFieldA8TextGeoProc);
#if GR_TEST_UTILS
sk_sp<GrGeometryProcessor> GrDistanceFieldA8TextGeoProc::TestCreate(GrProcessorTestData* d) {
int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx
: GrProcessorUnitTest::kAlphaTextureIdx;
sk_sp<GrTextureProxy> proxy = d->textureProxy(texIdx);
static const SkShader::TileMode kTileModes[] = {
SkShader::kClamp_TileMode,
SkShader::kRepeat_TileMode,
SkShader::kMirror_TileMode,
};
SkShader::TileMode tileModes[] = {
kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
};
GrSamplerParams params(tileModes, d->fRandom->nextBool() ? GrSamplerParams::kBilerp_FilterMode
: GrSamplerParams::kNone_FilterMode);
uint32_t flags = 0;
flags |= d->fRandom->nextBool() ? kSimilarity_DistanceFieldEffectFlag : 0;
if (flags & kSimilarity_DistanceFieldEffectFlag) {
flags |= d->fRandom->nextBool() ? kScaleOnly_DistanceFieldEffectFlag : 0;
}
return GrDistanceFieldA8TextGeoProc::Make(d->resourceProvider(),
GrRandomColor(d->fRandom),
GrTest::TestMatrix(d->fRandom),
std::move(proxy), params,
#ifdef SK_GAMMA_APPLY_TO_A8
d->fRandom->nextF(),
#endif
flags,
d->fRandom->nextBool());
}
#endif
///////////////////////////////////////////////////////////////////////////////
class GrGLDistanceFieldPathGeoProc : public GrGLSLGeometryProcessor {
public:
GrGLDistanceFieldPathGeoProc()
: fViewMatrix(SkMatrix::InvalidMatrix())
, fTextureSize(SkISize::Make(-1, -1)) {}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldPathGeoProc& dfTexEffect = args.fGP.cast<GrDistanceFieldPathGeoProc>();
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(dfTexEffect);
GrGLSLVertToFrag v(kVec2f_GrSLType);
varyingHandler->addVarying("TextureCoords", &v, kHigh_GrSLPrecision);
// setup pass through color
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
vertBuilder->codeAppendf("%s = %s;", v.vsOut(), dfTexEffect.inTextureCoords()->fName);
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
dfTexEffect.inPosition()->fName,
dfTexEffect.viewMatrix(),
&fViewMatrixUniform);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
dfTexEffect.inPosition()->fName,
args.fFPCoordTransformHandler);
const char* textureSizeUniName = nullptr;
fTextureSizeUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"TextureSize", &textureSizeUniName);
// Use highp to work around aliasing issues
fragBuilder->codeAppendf("highp vec2 uv = %s;", v.fsIn());
fragBuilder->codeAppend("float texColor = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0],
"uv",
kVec2f_GrSLType);
fragBuilder->codeAppend(".r;");
fragBuilder->codeAppend("float distance = "
SK_DistanceFieldMultiplier "*(texColor - " SK_DistanceFieldThreshold ");");
fragBuilder->codeAppendf("highp vec2 st = uv*%s;", textureSizeUniName);
fragBuilder->codeAppend("float afwidth;");
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
bool isGammaCorrect =
SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
if (isUniformScale) {
// For uniform scale, we adjust for the effect of the transformation on the distance
// by using the length of the gradient of the t coordinate in the y direction.
// We use st coordinates to ensure we're mapping 1:1 from texel space to pixel space.
// this gives us a smooth step across approximately one fragment
#ifdef SK_VULKAN
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdx(st.x));");
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(st.y));");
#endif
} else if (isSimilarity) {
// For similarity transform, we adjust the effect of the transformation on the distance
// by using the length of the gradient of the texture coordinates. We use st coordinates
// to ensure we're mapping 1:1 from texel space to pixel space.
// this gives us a smooth step across approximately one fragment
#ifdef SK_VULKAN
fragBuilder->codeAppend("float st_grad_len = length(dFdx(st));");
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppend("float st_grad_len = length(dFdy(st));");
#endif
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*st_grad_len);");
} else {
// For general transforms, to determine the amount of correction we multiply a unit
// vector pointing along the SDF gradient direction by the Jacobian of the st coords
// (which is the inverse transform for this fragment) and take the length of the result.
fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance), dFdy(distance));");
// the length of the gradient may be 0, so we need to check for this
// this also compensates for the Adreno, which likes to drop tiles on division by 0
fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
}
// The smoothstep falloff compensates for the non-linear sRGB response curve. If we are
// doing gamma-correct rendering (to an sRGB or F16 buffer), then we actually want distance
// mapped linearly to coverage, so use a linear step:
if (isGammaCorrect) {
fragBuilder->codeAppend(
"float val = clamp(distance + afwidth / (2.0 * afwidth), 0.0, 1.0);");
} else {
fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
}
fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
}
void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& proc,
FPCoordTransformIter&& transformIter) override {
SkASSERT(fTextureSizeUni.isValid());
GrTexture* texture = proc.textureSampler(0).texture();
if (texture->width() != fTextureSize.width() ||
texture->height() != fTextureSize.height()) {
fTextureSize = SkISize::Make(texture->width(), texture->height());
pdman.set2f(fTextureSizeUni,
SkIntToScalar(fTextureSize.width()),
SkIntToScalar(fTextureSize.height()));
}
const GrDistanceFieldPathGeoProc& dfpgp = proc.cast<GrDistanceFieldPathGeoProc>();
if (!dfpgp.viewMatrix().isIdentity() && !fViewMatrix.cheapEqualTo(dfpgp.viewMatrix())) {
fViewMatrix = dfpgp.viewMatrix();
float viewMatrix[3 * 3];
GrGLSLGetMatrix<3>(viewMatrix, fViewMatrix);
pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
}
this->setTransformDataHelper(SkMatrix::I(), pdman, &transformIter);
}
static inline void GenKey(const GrGeometryProcessor& gp,
const GrShaderCaps&,
GrProcessorKeyBuilder* b) {
const GrDistanceFieldPathGeoProc& dfTexEffect = gp.cast<GrDistanceFieldPathGeoProc>();
uint32_t key = dfTexEffect.getFlags();
key |= ComputePosKey(dfTexEffect.viewMatrix()) << 16;
b->add32(key);
}
private:
UniformHandle fTextureSizeUni;
UniformHandle fViewMatrixUniform;
SkMatrix fViewMatrix;
SkISize fTextureSize;
typedef GrGLSLGeometryProcessor INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
GrDistanceFieldPathGeoProc::GrDistanceFieldPathGeoProc(
GrResourceProvider* resourceProvider,
GrColor color,
const SkMatrix& viewMatrix,
sk_sp<GrTextureProxy> proxy,
const GrSamplerParams& params,
uint32_t flags,
bool usesLocalCoords)
: fColor(color)
, fViewMatrix(viewMatrix)
, fTextureSampler(resourceProvider, std::move(proxy), params)
, fFlags(flags & kNonLCD_DistanceFieldEffectMask)
, fInColor(nullptr)
, fUsesLocalCoords(usesLocalCoords) {
SkASSERT(!(flags & ~kNonLCD_DistanceFieldEffectMask));
this->initClassID<GrDistanceFieldPathGeoProc>();
fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
kHigh_GrSLPrecision);
fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
fInTextureCoords = &this->addVertexAttrib("inTextureCoords", kVec2us_GrVertexAttribType);
this->addTextureSampler(&fTextureSampler);
}
void GrDistanceFieldPathGeoProc::getGLSLProcessorKey(const GrShaderCaps& caps,
GrProcessorKeyBuilder* b) const {
GrGLDistanceFieldPathGeoProc::GenKey(*this, caps, b);
}
GrGLSLPrimitiveProcessor*
GrDistanceFieldPathGeoProc::createGLSLInstance(const GrShaderCaps&) const {
return new GrGLDistanceFieldPathGeoProc();
}
///////////////////////////////////////////////////////////////////////////////
GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrDistanceFieldPathGeoProc);
#if GR_TEST_UTILS
sk_sp<GrGeometryProcessor> GrDistanceFieldPathGeoProc::TestCreate(GrProcessorTestData* d) {
int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx
: GrProcessorUnitTest::kAlphaTextureIdx;
sk_sp<GrTextureProxy> proxy = d->textureProxy(texIdx);
static const SkShader::TileMode kTileModes[] = {
SkShader::kClamp_TileMode,
SkShader::kRepeat_TileMode,
SkShader::kMirror_TileMode,
};
SkShader::TileMode tileModes[] = {
kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
};
GrSamplerParams params(tileModes, d->fRandom->nextBool() ? GrSamplerParams::kBilerp_FilterMode
: GrSamplerParams::kNone_FilterMode);
uint32_t flags = 0;
flags |= d->fRandom->nextBool() ? kSimilarity_DistanceFieldEffectFlag : 0;
if (flags & kSimilarity_DistanceFieldEffectFlag) {
flags |= d->fRandom->nextBool() ? kScaleOnly_DistanceFieldEffectFlag : 0;
}
return GrDistanceFieldPathGeoProc::Make(d->resourceProvider(),
GrRandomColor(d->fRandom),
GrTest::TestMatrix(d->fRandom),
std::move(proxy),
params,
flags,
d->fRandom->nextBool());
}
#endif
///////////////////////////////////////////////////////////////////////////////
class GrGLDistanceFieldLCDTextGeoProc : public GrGLSLGeometryProcessor {
public:
GrGLDistanceFieldLCDTextGeoProc()
: fViewMatrix(SkMatrix::InvalidMatrix()) {
fDistanceAdjust = GrDistanceFieldLCDTextGeoProc::DistanceAdjust::Make(1.0f, 1.0f, 1.0f);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldLCDTextGeoProc& dfTexEffect =
args.fGP.cast<GrDistanceFieldLCDTextGeoProc>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(dfTexEffect);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// setup pass through color
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
dfTexEffect.inPosition()->fName,
dfTexEffect.viewMatrix(),
&fViewMatrixUniform);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
dfTexEffect.inPosition()->fName,
args.fFPCoordTransformHandler);
// set up varyings
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
bool isGammaCorrect =
SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
GrGLSLVertToFrag recipScale(kFloat_GrSLType);
GrGLSLVertToFrag uv(kVec2f_GrSLType);
varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);
// compute numbers to be hardcoded to convert texture coordinates from float to int
SkASSERT(dfTexEffect.numTextureSamplers() == 1);
GrTexture* atlas = dfTexEffect.textureSampler(0).texture();
SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
GrGLSLVertToFrag st(kVec2f_GrSLType);
varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
atlas->width(), atlas->height(),
dfTexEffect.inTextureCoords()->fName);
// add frag shader code
// create LCD offset adjusted by inverse of transform
// Use highp to work around aliasing issues
fragBuilder->codeAppendf("highp vec2 uv = %s;\n", uv.fsIn());
SkScalar lcdDelta = 1.0f / (3.0f * atlas->width());
if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
fragBuilder->codeAppendf("highp float delta = -%.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
} else {
fragBuilder->codeAppendf("highp float delta = %.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
}
if (isUniformScale) {
#ifdef SK_VULKAN
fragBuilder->codeAppendf("float st_grad_len = abs(dFdx(%s.x));", st.fsIn());
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppendf("float st_grad_len = abs(dFdy(%s.y));", st.fsIn());
#endif
fragBuilder->codeAppend("vec2 offset = vec2(st_grad_len*delta, 0.0);");
} else if (isSimilarity) {
// For a similarity matrix with rotation, the gradient will not be aligned
// with the texel coordinate axes, so we need to calculate it.
#ifdef SK_VULKAN
fragBuilder->codeAppendf("vec2 st_grad = dFdx(%s);", st.fsIn());
fragBuilder->codeAppend("vec2 offset = delta*st_grad;");
#else
// We use dFdy because of a Mali 400 bug, and rotate -90 degrees to
// get the gradient in the x direction.
fragBuilder->codeAppendf("vec2 st_grad = dFdy(%s);", st.fsIn());
fragBuilder->codeAppend("vec2 offset = delta*vec2(st_grad.y, -st_grad.x);");
#endif
fragBuilder->codeAppend("float st_grad_len = length(st_grad);");
} else {
fragBuilder->codeAppendf("vec2 st = %s;\n", st.fsIn());
fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
fragBuilder->codeAppend("vec2 offset = delta*Jdx;");
}
// green is distance to uv center
fragBuilder->codeAppend("\tvec4 texColor = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0], "uv", kVec2f_GrSLType);
fragBuilder->codeAppend(";\n");
fragBuilder->codeAppend("\tvec3 distance;\n");
fragBuilder->codeAppend("\tdistance.y = texColor.r;\n");
// red is distance to left offset
fragBuilder->codeAppend("\tvec2 uv_adjusted = uv - offset;\n");
fragBuilder->codeAppend("\ttexColor = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0], "uv_adjusted", kVec2f_GrSLType);
fragBuilder->codeAppend(";\n");
fragBuilder->codeAppend("\tdistance.x = texColor.r;\n");
// blue is distance to right offset
fragBuilder->codeAppend("\tuv_adjusted = uv + offset;\n");
fragBuilder->codeAppend("\ttexColor = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0], "uv_adjusted", kVec2f_GrSLType);
fragBuilder->codeAppend(";\n");
fragBuilder->codeAppend("\tdistance.z = texColor.r;\n");
fragBuilder->codeAppend("\tdistance = "
"vec3(" SK_DistanceFieldMultiplier ")*(distance - vec3(" SK_DistanceFieldThreshold"));");
// adjust width based on gamma
const char* distanceAdjustUniName = nullptr;
fDistanceAdjustUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec3f_GrSLType, kDefault_GrSLPrecision,
"DistanceAdjust", &distanceAdjustUniName);
fragBuilder->codeAppendf("distance -= %s;", distanceAdjustUniName);
// To be strictly correct, we should compute the anti-aliasing factor separately
// for each color component. However, this is only important when using perspective
// transformations, and even then using a single factor seems like a reasonable
// trade-off between quality and speed.
fragBuilder->codeAppend("float afwidth;");
if (isSimilarity) {
// For similarity transform (uniform scale-only is a subset of this), we adjust for the
// effect of the transformation on the distance by using the length of the gradient of
// the texture coordinates. We use st coordinates to ensure we're mapping 1:1 from texel
// space to pixel space.
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*st_grad_len;");
} else {
// For general transforms, to determine the amount of correction we multiply a unit
// vector pointing along the SDF gradient direction by the Jacobian of the st coords
// (which is the inverse transform for this fragment) and take the length of the result.
fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance.r), dFdy(distance.r));");
// the length of the gradient may be 0, so we need to check for this
// this also compensates for the Adreno, which likes to drop tiles on division by 0
fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
}
// The smoothstep falloff compensates for the non-linear sRGB response curve. If we are
// doing gamma-correct rendering (to an sRGB or F16 buffer), then we actually want distance
// mapped linearly to coverage, so use a linear step:
if (isGammaCorrect) {
fragBuilder->codeAppend("vec4 val = "
"vec4(clamp(distance + vec3(afwidth) / vec3(2.0 * afwidth), 0.0, 1.0), 1.0);");
} else {
fragBuilder->codeAppend(
"vec4 val = vec4(smoothstep(vec3(-afwidth), vec3(afwidth), distance), 1.0);");
}
// set alpha to be max of rgb coverage
fragBuilder->codeAppend("val.a = max(max(val.r, val.g), val.b);");
fragBuilder->codeAppendf("%s = val;", args.fOutputCoverage);
}
void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& processor,
FPCoordTransformIter&& transformIter) override {
SkASSERT(fDistanceAdjustUni.isValid());
const GrDistanceFieldLCDTextGeoProc& dflcd = processor.cast<GrDistanceFieldLCDTextGeoProc>();
GrDistanceFieldLCDTextGeoProc::DistanceAdjust wa = dflcd.getDistanceAdjust();
if (wa != fDistanceAdjust) {
pdman.set3f(fDistanceAdjustUni,
wa.fR,
wa.fG,
wa.fB);
fDistanceAdjust = wa;
}
if (!dflcd.viewMatrix().isIdentity() && !fViewMatrix.cheapEqualTo(dflcd.viewMatrix())) {
fViewMatrix = dflcd.viewMatrix();
float viewMatrix[3 * 3];
GrGLSLGetMatrix<3>(viewMatrix, fViewMatrix);
pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
}
this->setTransformDataHelper(SkMatrix::I(), pdman, &transformIter);
}
static inline void GenKey(const GrGeometryProcessor& gp,
const GrShaderCaps&,
GrProcessorKeyBuilder* b) {
const GrDistanceFieldLCDTextGeoProc& dfTexEffect = gp.cast<GrDistanceFieldLCDTextGeoProc>();
uint32_t key = dfTexEffect.getFlags();
key |= ComputePosKey(dfTexEffect.viewMatrix()) << 16;
b->add32(key);
// Currently we hardcode numbers to convert atlas coordinates to normalized floating point
SkASSERT(gp.numTextureSamplers() == 1);
GrTexture* atlas = gp.textureSampler(0).texture();
SkASSERT(atlas);
b->add32(atlas->width());
b->add32(atlas->height());
}
private:
SkMatrix fViewMatrix;
UniformHandle fViewMatrixUniform;
UniformHandle fColorUniform;
GrDistanceFieldLCDTextGeoProc::DistanceAdjust fDistanceAdjust;
UniformHandle fDistanceAdjustUni;
typedef GrGLSLGeometryProcessor INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
GrDistanceFieldLCDTextGeoProc::GrDistanceFieldLCDTextGeoProc(
GrResourceProvider* resourceProvider,
GrColor color, const SkMatrix& viewMatrix,
sk_sp<GrTextureProxy> proxy,
const GrSamplerParams& params,
DistanceAdjust distanceAdjust,
uint32_t flags, bool usesLocalCoords)
: fColor(color)
, fViewMatrix(viewMatrix)
, fTextureSampler(resourceProvider, std::move(proxy), params)
, fDistanceAdjust(distanceAdjust)
, fFlags(flags & kLCD_DistanceFieldEffectMask)
, fUsesLocalCoords(usesLocalCoords) {
SkASSERT(!(flags & ~kLCD_DistanceFieldEffectMask) && (flags & kUseLCD_DistanceFieldEffectFlag));
this->initClassID<GrDistanceFieldLCDTextGeoProc>();
fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
kHigh_GrSLPrecision);
fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
fInTextureCoords = &this->addVertexAttrib("inTextureCoords", kVec2us_GrVertexAttribType,
kHigh_GrSLPrecision);
this->addTextureSampler(&fTextureSampler);
}
void GrDistanceFieldLCDTextGeoProc::getGLSLProcessorKey(const GrShaderCaps& caps,
GrProcessorKeyBuilder* b) const {
GrGLDistanceFieldLCDTextGeoProc::GenKey(*this, caps, b);
}
GrGLSLPrimitiveProcessor* GrDistanceFieldLCDTextGeoProc::createGLSLInstance(const GrShaderCaps&) const {
return new GrGLDistanceFieldLCDTextGeoProc();
}
///////////////////////////////////////////////////////////////////////////////
GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrDistanceFieldLCDTextGeoProc);
#if GR_TEST_UTILS
sk_sp<GrGeometryProcessor> GrDistanceFieldLCDTextGeoProc::TestCreate(GrProcessorTestData* d) {
int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
GrProcessorUnitTest::kAlphaTextureIdx;
sk_sp<GrTextureProxy> proxy = d->textureProxy(texIdx);
static const SkShader::TileMode kTileModes[] = {
SkShader::kClamp_TileMode,
SkShader::kRepeat_TileMode,
SkShader::kMirror_TileMode,
};
SkShader::TileMode tileModes[] = {
kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
};
GrSamplerParams params(tileModes, d->fRandom->nextBool() ? GrSamplerParams::kBilerp_FilterMode
: GrSamplerParams::kNone_FilterMode);
DistanceAdjust wa = { 0.0f, 0.1f, -0.1f };
uint32_t flags = kUseLCD_DistanceFieldEffectFlag;
flags |= d->fRandom->nextBool() ? kSimilarity_DistanceFieldEffectFlag : 0;
if (flags & kSimilarity_DistanceFieldEffectFlag) {
flags |= d->fRandom->nextBool() ? kScaleOnly_DistanceFieldEffectFlag : 0;
}
flags |= d->fRandom->nextBool() ? kBGR_DistanceFieldEffectFlag : 0;
return GrDistanceFieldLCDTextGeoProc::Make(d->resourceProvider(),
GrRandomColor(d->fRandom),
GrTest::TestMatrix(d->fRandom),
std::move(proxy), params,
wa,
flags,
d->fRandom->nextBool());
}
#endif