void onEmitCode(EmitArgs& args) override {
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// add uniform
const char* xformUniName = nullptr;
fXformUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kMat22f_GrSLType,
kDefault_GrSLPrecision, "Xform", &xformUniName);
SkString dstNormalColorName("dstNormalColor");
this->emitChild(0, nullptr, &dstNormalColorName, args);
fragBuilder->codeAppendf("vec3 normal = normalize(%s.rgb - vec3(0.5));",
dstNormalColorName.c_str());
// If there's no x & y components, return (0, 0, +/- 1) instead to avoid division by 0
fragBuilder->codeAppend( "if (abs(normal.z) > 0.999) {");
fragBuilder->codeAppendf(" %s = normalize(vec4(0.0, 0.0, normal.z, 0.0));",
args.fOutputColor);
// Else, Normalizing the transformed X and Y, while keeping constant both Z and the
// vector's angle in the XY plane. This maintains the "slope" for the surface while
// appropriately rotating the normal regardless of any anisotropic scaling that occurs.
// Here, we call 'scaling factor' the number that must divide the transformed X and Y so
// that the normal's length remains equal to 1.
fragBuilder->codeAppend( "} else {");
fragBuilder->codeAppendf(" vec2 transformed = %s * normal.xy;",
xformUniName);
fragBuilder->codeAppend( " float scalingFactorSquared = "
"( (transformed.x * transformed.x) "
"+ (transformed.y * transformed.y) )"
"/(1.0 - (normal.z * normal.z));");
fragBuilder->codeAppendf(" %s = vec4(transformed*inversesqrt(scalingFactorSquared),"
"normal.z, 0.0);",
args.fOutputColor);
fragBuilder->codeAppend( "}");
}
void emitCode(EmitArgs& args) override {
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fMatrixHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
kMat44f_GrSLType, kDefault_GrSLPrecision,
"ColorMatrix");
fVectorHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
kVec4f_GrSLType, kDefault_GrSLPrecision,
"ColorMatrixVector");
if (nullptr == args.fInputColor) {
// could optimize this case, but we aren't for now.
args.fInputColor = "vec4(1)";
}
GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
// The max() is to guard against 0 / 0 during unpremul when the incoming color is
// transparent black.
fragBuilder->codeAppendf("\tfloat nonZeroAlpha = max(%s.a, 0.00001);\n",
args.fInputColor);
fragBuilder->codeAppendf("\t%s = %s * vec4(%s.rgb / nonZeroAlpha, nonZeroAlpha) + %s;\n",
args.fOutputColor,
uniformHandler->getUniformCStr(fMatrixHandle),
args.fInputColor,
uniformHandler->getUniformCStr(fVectorHandle));
fragBuilder->codeAppendf("\t%s = clamp(%s, 0.0, 1.0);\n",
args.fOutputColor, args.fOutputColor);
fragBuilder->codeAppendf("\t%s.rgb *= %s.a;\n", args.fOutputColor, args.fOutputColor);
}
void GrGLSLXferProcessor::emitCode(const EmitArgs& args) {
if (!args.fXP.willReadDstColor()) {
this->emitOutputsForBlendState(args);
return;
}
GrGLSLXPFragmentBuilder* fragBuilder = args.fXPFragBuilder;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
const char* dstColor = fragBuilder->dstColor();
if (args.fXP.getDstTexture()) {
bool topDown = kTopLeft_GrSurfaceOrigin == args.fXP.getDstTexture()->origin();
if (args.fInputCoverage) {
// We don't think any shaders actually output negative coverage, but just as a safety
// check for floating point precision errors we compare with <= here
fragBuilder->codeAppendf("if (all(lessThanEqual(%s, vec4(0)))) {"
" discard;"
"}", args.fInputCoverage);
}
const char* dstTopLeftName;
const char* dstCoordScaleName;
fDstTopLeftUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType,
kDefault_GrSLPrecision,
"DstTextureUpperLeft",
&dstTopLeftName);
fDstScaleUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType,
kDefault_GrSLPrecision,
"DstTextureCoordScale",
&dstCoordScaleName);
const char* fragPos = fragBuilder->fragmentPosition();
fragBuilder->codeAppend("// Read color from copy of the destination.\n");
fragBuilder->codeAppendf("vec2 _dstTexCoord = (%s.xy - %s) * %s;",
fragPos, dstTopLeftName, dstCoordScaleName);
if (!topDown) {
fragBuilder->codeAppend("_dstTexCoord.y = 1.0 - _dstTexCoord.y;");
}
fragBuilder->codeAppendf("vec4 %s = ", dstColor);
fragBuilder->appendTextureLookup(args.fTexSamplers[0], "_dstTexCoord", kVec2f_GrSLType);
fragBuilder->codeAppend(";");
}
this->emitBlendCodeForDstRead(fragBuilder,
uniformHandler,
args.fInputColor,
args.fInputCoverage,
dstColor,
args.fOutputPrimary,
args.fOutputSecondary,
args.fXP);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const GrBitmapTextGeoProc& btgp = args.fGP.cast<GrBitmapTextGeoProc>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(btgp);
const char* atlasSizeInvName;
fAtlasSizeInvUniform = uniformHandler->addUniform(kVertex_GrShaderFlag,
kFloat2_GrSLType,
kHigh_GrSLPrecision,
"AtlasSizeInv",
&atlasSizeInvName);
GrGLSLVarying uv(kFloat2_GrSLType);
GrSLType texIdxType = args.fShaderCaps->integerSupport() ? kInt_GrSLType : kFloat_GrSLType;
GrGLSLVarying texIdx(texIdxType);
append_index_uv_varyings(args, btgp.inTextureCoords().name(), atlasSizeInvName, &uv,
&texIdx, nullptr);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup pass through color
if (btgp.hasVertexColor()) {
varyingHandler->addPassThroughAttribute(btgp.inColor(), args.fOutputColor);
} else {
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor,
&fColorUniform);
}
// Setup position
gpArgs->fPositionVar = btgp.inPosition().asShaderVar();
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
btgp.inPosition().asShaderVar(),
btgp.localMatrix(),
args.fFPCoordTransformHandler);
fragBuilder->codeAppend("half4 texColor;");
append_multitexture_lookup(args, btgp.numTextureSamplers(),
texIdx, uv.fsIn(), "texColor");
if (btgp.maskFormat() == kARGB_GrMaskFormat) {
// modulate by color
fragBuilder->codeAppendf("%s = %s * texColor;", args.fOutputColor, args.fOutputColor);
fragBuilder->codeAppendf("%s = half4(1);", args.fOutputCoverage);
} else {
fragBuilder->codeAppendf("%s = texColor;", args.fOutputCoverage);
}
}
void GrColorCubeEffect::GLSLProcessor::emitCode(EmitArgs& args) {
if (nullptr == args.fInputColor) {
args.fInputColor = "vec4(1)";
}
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fColorCubeSizeUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kDefault_GrSLPrecision,
"Size");
const char* colorCubeSizeUni = uniformHandler->getUniformCStr(fColorCubeSizeUni);
fColorCubeInvSizeUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kDefault_GrSLPrecision,
"InvSize");
const char* colorCubeInvSizeUni = uniformHandler->getUniformCStr(fColorCubeInvSizeUni);
const char* nonZeroAlpha = "nonZeroAlpha";
const char* unPMColor = "unPMColor";
const char* cubeIdx = "cubeIdx";
const char* cCoords1 = "cCoords1";
const char* cCoords2 = "cCoords2";
// Note: if implemented using texture3D in OpenGL ES older than OpenGL ES 3.0,
// the shader might need "#extension GL_OES_texture_3D : enable".
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Unpremultiply color
fragBuilder->codeAppendf("\tfloat %s = max(%s.a, 0.00001);\n", nonZeroAlpha, args.fInputColor);
fragBuilder->codeAppendf("\tvec4 %s = vec4(%s.rgb / %s, %s);\n",
unPMColor, args.fInputColor, nonZeroAlpha, nonZeroAlpha);
// Fit input color into the cube.
fragBuilder->codeAppendf(
"vec3 %s = vec3(%s.rg * vec2((%s - 1.0) * %s) + vec2(0.5 * %s), %s.b * (%s - 1.0));\n",
cubeIdx, unPMColor, colorCubeSizeUni, colorCubeInvSizeUni, colorCubeInvSizeUni,
unPMColor, colorCubeSizeUni);
// Compute y coord for for texture fetches.
fragBuilder->codeAppendf("vec2 %s = vec2(%s.r, (floor(%s.b) + %s.g) * %s);\n",
cCoords1, cubeIdx, cubeIdx, cubeIdx, colorCubeInvSizeUni);
fragBuilder->codeAppendf("vec2 %s = vec2(%s.r, (ceil(%s.b) + %s.g) * %s);\n",
cCoords2, cubeIdx, cubeIdx, cubeIdx, colorCubeInvSizeUni);
// Apply the cube.
fragBuilder->codeAppendf("%s = vec4(mix(", args.fOutputColor);
fragBuilder->appendTextureLookup(args.fSamplers[0], cCoords1);
fragBuilder->codeAppend(".bgr, ");
fragBuilder->appendTextureLookup(args.fSamplers[0], cCoords2);
// Premultiply color by alpha. Note that the input alpha is not modified by this shader.
fragBuilder->codeAppendf(".bgr, fract(%s.b)) * vec3(%s), %s.a);\n",
cubeIdx, nonZeroAlpha, args.fInputColor);
}
void GrGLMagnifierEffect::emitCode(EmitArgs& args) {
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fOffsetVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"Offset");
fInvZoomVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"InvZoom");
fInvInsetVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"InvInset");
fBoundsVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec4f_GrSLType, kDefault_GrSLPrecision,
"Bounds");
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
fragBuilder->codeAppendf("\t\tvec2 coord = %s;\n", coords2D.c_str());
fragBuilder->codeAppendf("\t\tvec2 zoom_coord = %s + %s * %s;\n",
uniformHandler->getUniformCStr(fOffsetVar),
coords2D.c_str(),
uniformHandler->getUniformCStr(fInvZoomVar));
const char* bounds = uniformHandler->getUniformCStr(fBoundsVar);
fragBuilder->codeAppendf("\t\tvec2 delta = (coord - %s.xy) * %s.zw;\n", bounds, bounds);
fragBuilder->codeAppendf("\t\tdelta = min(delta, vec2(1.0, 1.0) - delta);\n");
fragBuilder->codeAppendf("\t\tdelta = delta * %s;\n",
uniformHandler->getUniformCStr(fInvInsetVar));
fragBuilder->codeAppend("\t\tfloat weight = 0.0;\n");
fragBuilder->codeAppend("\t\tif (delta.s < 2.0 && delta.t < 2.0) {\n");
fragBuilder->codeAppend("\t\t\tdelta = vec2(2.0, 2.0) - delta;\n");
fragBuilder->codeAppend("\t\t\tfloat dist = length(delta);\n");
fragBuilder->codeAppend("\t\t\tdist = max(2.0 - dist, 0.0);\n");
fragBuilder->codeAppend("\t\t\tweight = min(dist * dist, 1.0);\n");
fragBuilder->codeAppend("\t\t} else {\n");
fragBuilder->codeAppend("\t\t\tvec2 delta_squared = delta * delta;\n");
fragBuilder->codeAppend("\t\t\tweight = min(min(delta_squared.x, delta_squared.y), 1.0);\n");
fragBuilder->codeAppend("\t\t}\n");
fragBuilder->codeAppend("\t\tvec2 mix_coord = mix(coord, zoom_coord, weight);\n");
fragBuilder->codeAppend("\t\tvec4 output_color = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0], "mix_coord");
fragBuilder->codeAppend(";\n");
fragBuilder->codeAppendf("\t\t%s = output_color;", args.fOutputColor);
SkString modulate;
GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
fragBuilder->codeAppend(modulate.c_str());
}
void GrGLAlphaThresholdFragmentProcessor::emitCode(EmitArgs& args) {
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fInnerThresholdVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kDefault_GrSLPrecision,
"inner_threshold");
fOuterThresholdVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kDefault_GrSLPrecision,
"outer_threshold");
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
SkString maskCoords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 1);
fragBuilder->codeAppendf("vec2 coord = %s;", coords2D.c_str());
fragBuilder->codeAppendf("vec2 mask_coord = %s;", maskCoords2D.c_str());
fragBuilder->codeAppend("vec4 input_color = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0], "coord");
fragBuilder->codeAppend(";");
fragBuilder->codeAppend("vec4 mask_color = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[1], "mask_coord");
fragBuilder->codeAppend(";");
fragBuilder->codeAppendf("float inner_thresh = %s;",
uniformHandler->getUniformCStr(fInnerThresholdVar));
fragBuilder->codeAppendf("float outer_thresh = %s;",
uniformHandler->getUniformCStr(fOuterThresholdVar));
fragBuilder->codeAppend("float mask = mask_color.a;");
fragBuilder->codeAppend("vec4 color = input_color;");
fragBuilder->codeAppend("if (mask < 0.5) {"
"if (color.a > outer_thresh) {"
"float scale = outer_thresh / color.a;"
"color.rgb *= scale;"
"color.a = outer_thresh;"
"}"
"} else if (color.a < inner_thresh) {"
"float scale = inner_thresh / max(0.001, color.a);"
"color.rgb *= scale;"
"color.a = inner_thresh;"
"}");
fragBuilder->codeAppendf("%s = %s;", args.fOutputColor,
(GrGLSLExpr4(args.fInputColor) * GrGLSLExpr4("color")).c_str());
}
void GrGLConvolutionEffect::emitCode(EmitArgs& args) {
const GrConvolutionEffect& ce = args.fFp.cast<GrConvolutionEffect>();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fImageIncrementUni = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"ImageIncrement");
if (ce.useBounds()) {
fBoundsUni = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"Bounds");
}
int width = Gr1DKernelEffect::WidthFromRadius(ce.radius());
fKernelUni = uniformHandler->addUniformArray(GrGLSLUniformHandler::kFragment_Visibility,
kFloat_GrSLType, kDefault_GrSLPrecision,
"Kernel", width);
GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
fragBuilder->codeAppendf("%s = vec4(0, 0, 0, 0);", args.fOutputColor);
const GrGLSLShaderVar& kernel = uniformHandler->getUniformVariable(fKernelUni);
const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni);
fragBuilder->codeAppendf("vec2 coord = %s - %d.0 * %s;", coords2D.c_str(), ce.radius(), imgInc);
// Manually unroll loop because some drivers don't; yields 20-30% speedup.
for (int i = 0; i < width; i++) {
SkString index;
SkString kernelIndex;
index.appendS32(i);
kernel.appendArrayAccess(index.c_str(), &kernelIndex);
if (ce.useBounds()) {
// We used to compute a bool indicating whether we're in bounds or not, cast it to a
// float, and then mul weight*texture_sample by the float. However, the Adreno 430 seems
// to have a bug that caused corruption.
const char* bounds = uniformHandler->getUniformCStr(fBoundsUni);
const char* component = ce.direction() == Gr1DKernelEffect::kY_Direction ? "y" : "x";
fragBuilder->codeAppendf("if (coord.%s >= %s.x && coord.%s <= %s.y) {",
component, bounds, component, bounds);
}
fragBuilder->codeAppendf("\t\t%s += ", args.fOutputColor);
fragBuilder->appendTextureLookup(args.fSamplers[0], "coord");
fragBuilder->codeAppendf(" * %s;\n", kernelIndex.c_str());
if (ce.useBounds()) {
fragBuilder->codeAppend("}");
}
fragBuilder->codeAppendf("\t\tcoord += %s;\n", imgInc);
}
SkString modulate;
GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
fragBuilder->codeAppend(modulate.c_str());
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const PLSFinishEffect& fe = args.fGP.cast<PLSFinishEffect>();
GrGLSLVertexBuilder* vsBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fUseEvenOdd = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kLow_GrSLPrecision,
"useEvenOdd");
const char* useEvenOdd = uniformHandler->getUniformCStr(fUseEvenOdd);
varyingHandler->emitAttributes(fe);
this->setupPosition(vsBuilder, gpArgs, fe.inPosition()->fName);
this->emitTransforms(vsBuilder, varyingHandler, uniformHandler, gpArgs->fPositionVar,
fe.inPosition()->fName, fe.localMatrix(), args.fTransformsIn,
args.fTransformsOut);
GrGLSLFragmentBuilder* fsBuilder = args.fFragBuilder;
SkAssertResult(fsBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kPixelLocalStorage_GLSLFeature));
fsBuilder->declAppendf(GR_GL_PLS_PATH_DATA_DECL);
fsBuilder->codeAppend("float coverage;");
fsBuilder->codeAppendf("if (%s != 0.0) {", useEvenOdd);
fsBuilder->codeAppend("coverage = float(abs(pls.windings[0]) % 2) * 0.25;");
fsBuilder->codeAppend("coverage += float(abs(pls.windings[1]) % 2) * 0.25;");
fsBuilder->codeAppend("coverage += float(abs(pls.windings[2]) % 2) * 0.25;");
fsBuilder->codeAppend("coverage += float(abs(pls.windings[3]) % 2) * 0.25;");
fsBuilder->codeAppend("} else {");
fsBuilder->codeAppend("coverage = pls.windings[0] != 0 ? 0.25 : 0.0;");
fsBuilder->codeAppend("coverage += pls.windings[1] != 0 ? 0.25 : 0.0;");
fsBuilder->codeAppend("coverage += pls.windings[2] != 0 ? 0.25 : 0.0;");
fsBuilder->codeAppend("coverage += pls.windings[3] != 0 ? 0.25 : 0.0;");
fsBuilder->codeAppend("}");
if (!fe.colorIgnored()) {
this->setupUniformColor(fsBuilder, uniformHandler, args.fOutputColor,
&fColorUniform);
}
fsBuilder->codeAppendf("%s = vec4(coverage);", args.fOutputCoverage);
fsBuilder->codeAppendf("%s = vec4(1.0, 0.0, 1.0, 1.0);", args.fOutputColor);
}
void GrGLSLShaderBuilder::appendTextureLookup(SkString* out,
const GrGLSLTextureSampler& sampler,
const char* coordName,
GrSLType varyingType) const {
const GrGLSLCaps* glslCaps = fProgramBuilder->glslCaps();
GrGLSLUniformHandler* uniformHandler = fProgramBuilder->uniformHandler();
GrSLType samplerType = uniformHandler->getUniformVariable(sampler.fSamplerUniform).getType();
if (samplerType == kSampler2DRect_GrSLType) {
if (varyingType == kVec2f_GrSLType) {
out->appendf("%s(%s, textureSize(%s) * %s)",
GrGLSLTexture2DFunctionName(varyingType, samplerType,
glslCaps->generation()),
uniformHandler->getUniformCStr(sampler.fSamplerUniform),
uniformHandler->getUniformCStr(sampler.fSamplerUniform),
coordName);
} else {
out->appendf("%s(%s, vec3(textureSize(%s) * %s.xy, %s.z))",
GrGLSLTexture2DFunctionName(varyingType, samplerType,
glslCaps->generation()),
uniformHandler->getUniformCStr(sampler.fSamplerUniform),
uniformHandler->getUniformCStr(sampler.fSamplerUniform),
coordName,
coordName);
}
} else {
out->appendf("%s(%s, %s)",
GrGLSLTexture2DFunctionName(varyingType, samplerType, glslCaps->generation()),
uniformHandler->getUniformCStr(sampler.fSamplerUniform),
coordName);
}
// This refers to any swizzling we may need to get from some backend internal format to the
// format used in GrPixelConfig. If this is implemented by the GrGpu object, then swizzle will
// be rgba. For shader prettiness we omit the swizzle rather than appending ".rgba".
const GrSwizzle& configSwizzle = glslCaps->configTextureSwizzle(sampler.config());
if (configSwizzle != GrSwizzle::RGBA()) {
out->appendf(".%s", configSwizzle.c_str());
}
}
void emitCode(EmitArgs& args) override {
const TwoPointConicalEffect& effect = args.fFp.cast<TwoPointConicalEffect>();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
this->emitUniforms(uniformHandler, effect);
fParamUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf_GrSLType,
"Conical2FSParams");
SkString p0; // r0 for radial case, r0^2 for strip case
p0.appendf("%s", uniformHandler->getUniformVariable(fParamUni).getName().c_str());
const char* tName = "t"; // the gradient
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
const char* p = coords2D.c_str();
if (effect.getType() == Type::kRadial) {
char sign = effect.diffRadius() < 0 ? '-' : '+';
fragBuilder->codeAppendf("half %s = %clength(%s) - %s;", tName, sign, p, p0.c_str());
} else {
// output will default to transparent black (we simply won't write anything
// else to it if invalid, instead of discarding or returning prematurely)
fragBuilder->codeAppendf("%s = half4(0.0,0.0,0.0,0.0);", args.fOutputColor);
fragBuilder->codeAppendf("half temp = %s - %s.y * %s.y;", p0.c_str(), p, p);
fragBuilder->codeAppendf("if (temp >= 0) {");
fragBuilder->codeAppendf("half %s = %s.x + sqrt(temp);", tName, p);
}
this->emitColor(fragBuilder,
uniformHandler,
args.fShaderCaps,
effect,
tName,
args.fOutputColor,
args.fInputColor,
args.fTexSamplers);
if (effect.getType() != Type::kRadial) {
fragBuilder->codeAppendf("}");
}
}
void GrGLPerlinNoise::emitCode(EmitArgs& args) {
const GrPerlinNoiseEffect& pne = args.fFp.cast<GrPerlinNoiseEffect>();
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
SkString vCoords = fragBuilder->ensureCoords2D(args.fTransformedCoords[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.fTexSamplers[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.fTexSamplers[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.fTexSamplers[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.fTexSamplers[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.fTexSamplers[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.fTexSamplers[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 GLCircularRRectEffect::emitCode(EmitArgs& args) {
const CircularRRectEffect& crre = args.fFp.cast<CircularRRectEffect>();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
const char *rectName;
const char *radiusPlusHalfName;
// The inner rect is the rrect bounds inset by the radius. Its left, top, right, and bottom
// edges correspond to components x, y, z, and w, respectively. When a side of the rrect has
// only rectangular corners, that side's value corresponds to the rect edge's value outset by
// half a pixel.
fInnerRectUniform = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf4_GrSLType,
"innerRect", &rectName);
// x is (r + .5) and y is 1/(r + .5)
fRadiusPlusHalfUniform = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType,
"radiusPlusHalf", &radiusPlusHalfName);
// If we're on a device where float != fp32 then the length calculation could overflow.
SkString clampedCircleDistance;
if (!args.fShaderCaps->floatIs32Bits()) {
clampedCircleDistance.printf("clamp(%s.x * (1.0 - length(dxy * %s.y)), 0.0, 1.0);",
radiusPlusHalfName, radiusPlusHalfName);
} else {
clampedCircleDistance.printf("clamp(%s.x - length(dxy), 0.0, 1.0);", radiusPlusHalfName);
}
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
// At each quarter-circle corner we compute a vector that is the offset of the fragment position
// from the circle center. The vector is pinned in x and y to be in the quarter-plane relevant
// to that corner. This means that points near the interior near the rrect top edge will have
// a vector that points straight up for both the TL left and TR corners. Computing an
// alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
// fragments near the other three edges will get the correct AA. Fragments in the interior of
// the rrect will have a (0,0) vector at all four corners. So long as the radius > 0.5 they will
// correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
// The code below is a simplified version of the above that performs maxs on the vector
// components before computing distances and alpha values so that only one distance computation
// need be computed to determine the min alpha.
//
// For the cases where one half of the rrect is rectangular we drop one of the x or y
// computations, compute a separate rect edge alpha for the rect side, and mul the two computed
// alphas together.
switch (crre.getCircularCornerFlags()) {
case CircularRRectEffect::kAll_CornerFlags:
fragBuilder->codeAppendf("float2 dxy0 = %s.xy - sk_FragCoord.xy;", rectName);
fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.zw;", rectName);
fragBuilder->codeAppend("float2 dxy = max(max(dxy0, dxy1), 0.0);");
fragBuilder->codeAppendf("half alpha = %s;", clampedCircleDistance.c_str());
break;
case CircularRRectEffect::kTopLeft_CornerFlag:
fragBuilder->codeAppendf("float2 dxy = max(%s.xy - sk_FragCoord.xy, 0.0);",
rectName);
fragBuilder->codeAppendf("half rightAlpha = clamp(%s.z - sk_FragCoord.x, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half bottomAlpha = clamp(%s.w - sk_FragCoord.y, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half alpha = bottomAlpha * rightAlpha * %s;",
clampedCircleDistance.c_str());
break;
case CircularRRectEffect::kTopRight_CornerFlag:
fragBuilder->codeAppendf("float2 dxy = max(float2(sk_FragCoord.x - %s.z, "
"%s.y - sk_FragCoord.y), 0.0);",
rectName, rectName);
fragBuilder->codeAppendf("half leftAlpha = clamp(sk_FragCoord.x - %s.x, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half bottomAlpha = clamp(%s.w - sk_FragCoord.y, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half alpha = bottomAlpha * leftAlpha * %s;",
clampedCircleDistance.c_str());
break;
case CircularRRectEffect::kBottomRight_CornerFlag:
fragBuilder->codeAppendf("float2 dxy = max(sk_FragCoord.xy - %s.zw, 0.0);",
rectName);
fragBuilder->codeAppendf("half leftAlpha = clamp(sk_FragCoord.x - %s.x, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half topAlpha = clamp(sk_FragCoord.y - %s.y, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half alpha = topAlpha * leftAlpha * %s;",
clampedCircleDistance.c_str());
break;
case CircularRRectEffect::kBottomLeft_CornerFlag:
fragBuilder->codeAppendf("float2 dxy = max(float2(%s.x - sk_FragCoord.x, "
"sk_FragCoord.y - %s.w), 0.0);",
rectName, rectName);
fragBuilder->codeAppendf("half rightAlpha = clamp(%s.z - sk_FragCoord.x, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half topAlpha = clamp(sk_FragCoord.y - %s.y, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half alpha = topAlpha * rightAlpha * %s;",
clampedCircleDistance.c_str());
break;
case CircularRRectEffect::kLeft_CornerFlags:
fragBuilder->codeAppendf("float2 dxy0 = %s.xy - sk_FragCoord.xy;", rectName);
fragBuilder->codeAppendf("float dy1 = sk_FragCoord.y - %s.w;", rectName);
fragBuilder->codeAppend("float2 dxy = max(float2(dxy0.x, max(dxy0.y, dy1)), 0.0);");
fragBuilder->codeAppendf("half rightAlpha = clamp(%s.z - sk_FragCoord.x, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half alpha = rightAlpha * %s;",
clampedCircleDistance.c_str());
break;
case CircularRRectEffect::kTop_CornerFlags:
fragBuilder->codeAppendf("float2 dxy0 = %s.xy - sk_FragCoord.xy;", rectName);
fragBuilder->codeAppendf("float dx1 = sk_FragCoord.x - %s.z;", rectName);
fragBuilder->codeAppend("float2 dxy = max(float2(max(dxy0.x, dx1), dxy0.y), 0.0);");
fragBuilder->codeAppendf("half bottomAlpha = clamp(%s.w - sk_FragCoord.y, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half alpha = bottomAlpha * %s;",
clampedCircleDistance.c_str());
break;
case CircularRRectEffect::kRight_CornerFlags:
fragBuilder->codeAppendf("float dy0 = %s.y - sk_FragCoord.y;", rectName);
fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.zw;", rectName);
fragBuilder->codeAppend("float2 dxy = max(float2(dxy1.x, max(dy0, dxy1.y)), 0.0);");
fragBuilder->codeAppendf("half leftAlpha = clamp(sk_FragCoord.x - %s.x, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half alpha = leftAlpha * %s;",
clampedCircleDistance.c_str());
break;
case CircularRRectEffect::kBottom_CornerFlags:
fragBuilder->codeAppendf("float dx0 = %s.x - sk_FragCoord.x;", rectName);
fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.zw;", rectName);
fragBuilder->codeAppend("float2 dxy = max(float2(max(dx0, dxy1.x), dxy1.y), 0.0);");
fragBuilder->codeAppendf("half topAlpha = clamp(sk_FragCoord.y - %s.y, 0.0, 1.0);",
rectName);
fragBuilder->codeAppendf("half alpha = topAlpha * %s;",
clampedCircleDistance.c_str());
break;
}
if (GrClipEdgeType::kInverseFillAA == crre.getEdgeType()) {
fragBuilder->codeAppend("alpha = 1.0 - alpha;");
}
fragBuilder->codeAppendf("%s = %s * alpha;", args.fOutputColor, args.fInputColor);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldPathGeoProc& dfTexEffect = args.fGP.cast<GrDistanceFieldPathGeoProc>();
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
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
if (!dfTexEffect.colorIgnored()) {
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->appendPrecisionModifier(kHigh_GrSLPrecision);
fragBuilder->codeAppendf("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->appendPrecisionModifier(kHigh_GrSLPrecision);
fragBuilder->codeAppendf("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 GrGLCubicEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
const GrCubicEffect& gp = args.fGP.cast<GrCubicEffect>();
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(gp);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup pass through color
if (!gp.colorIgnored()) {
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor, &fColorUniform);
}
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
gp.inPosition()->fName,
gp.viewMatrix(),
&fViewMatrixUniform);
// Setup KLM
const char* devkLMMatrixName;
fDevKLMUniform = uniformHandler->addUniform(kVertex_GrShaderFlag, kMat33f_GrSLType,
kHigh_GrSLPrecision, "KLM", &devkLMMatrixName);
GrGLSLVertToFrag v(kVec3f_GrSLType);
varyingHandler->addVarying("CubicCoeffs", &v, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = %s * vec3(%s, 1);",
v.vsOut(), devkLMMatrixName, gpArgs->fPositionVar.c_str());
GrGLSLVertToFrag gradCoeffs(kVec4f_GrSLType);
if (kFillAA_GrProcessorEdgeType == fEdgeType || kHairlineAA_GrProcessorEdgeType == fEdgeType) {
varyingHandler->addVarying("GradCoeffs", &gradCoeffs, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("highp float k = %s[0], l = %s[1], m = %s[2];",
v.vsOut(), v.vsOut(), v.vsOut());
vertBuilder->codeAppendf("highp vec2 gk = vec2(%s[0][0], %s[1][0]), "
"gl = vec2(%s[0][1], %s[1][1]), "
"gm = vec2(%s[0][2], %s[1][2]);",
devkLMMatrixName, devkLMMatrixName, devkLMMatrixName,
devkLMMatrixName, devkLMMatrixName, devkLMMatrixName);
vertBuilder->codeAppendf("%s = vec4(3 * k * gk, -m * gl - l * gm);",
gradCoeffs.vsOut());
}
// emit transforms with position
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
gp.inPosition()->fName,
args.fFPCoordTransformHandler);
GrShaderVar edgeAlpha("edgeAlpha", kFloat_GrSLType, 0, kHigh_GrSLPrecision);
GrShaderVar gF("gF", kVec2f_GrSLType, 0, kHigh_GrSLPrecision);
GrShaderVar func("func", kFloat_GrSLType, 0, kHigh_GrSLPrecision);
fragBuilder->declAppend(edgeAlpha);
fragBuilder->declAppend(gF);
fragBuilder->declAppend(func);
switch (fEdgeType) {
case kHairlineAA_GrProcessorEdgeType: {
fragBuilder->codeAppendf("%s = %s.x * %s.xy + %s.zw;",
gF.c_str(), v.fsIn(), gradCoeffs.fsIn(), gradCoeffs.fsIn());
fragBuilder->codeAppendf("%s = %s.x * %s.x * %s.x - %s.y * %s.z;",
func.c_str(), v.fsIn(), v.fsIn(),
v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("%s = abs(%s);", func.c_str(), func.c_str());
fragBuilder->codeAppendf("%s = %s * inversesqrt(dot(%s, %s));",
edgeAlpha.c_str(), func.c_str(), gF.c_str(), gF.c_str());
fragBuilder->codeAppendf("%s = max(1.0 - %s, 0.0);",
edgeAlpha.c_str(), edgeAlpha.c_str());
// Add line below for smooth cubic ramp
// fragBuilder->codeAppendf("%s = %s * %s * (3.0 - 2.0 * %s);",
// edgeAlpha.c_str(), edgeAlpha.c_str(), edgeAlpha.c_str(),
// edgeAlpha.c_str());
break;
}
case kFillAA_GrProcessorEdgeType: {
fragBuilder->codeAppendf("%s = %s.x * %s.xy + %s.zw;",
gF.c_str(), v.fsIn(), gradCoeffs.fsIn(), gradCoeffs.fsIn());
fragBuilder->codeAppendf("%s = %s.x * %s.x * %s.x - %s.y * %s.z;",
func.c_str(),
v.fsIn(), v.fsIn(), v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("%s = %s * inversesqrt(dot(%s, %s));",
edgeAlpha.c_str(), func.c_str(), gF.c_str(), gF.c_str());
fragBuilder->codeAppendf("%s = clamp(0.5 - %s, 0.0, 1.0);",
edgeAlpha.c_str(), edgeAlpha.c_str());
// Add line below for smooth cubic ramp
// fragBuilder->codeAppendf("%s = %s * %s * (3.0 - 2.0 * %s);",
// edgeAlpha.c_str(), edgeAlpha.c_str(), edgeAlpha.c_str(),
// edgeAlpha.c_str());
break;
}
case kFillBW_GrProcessorEdgeType: {
fragBuilder->codeAppendf("%s = %s.x * %s.x * %s.x - %s.y * %s.z;",
edgeAlpha.c_str(), v.fsIn(), v.fsIn(),
v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("%s = float(%s < 0.0);", edgeAlpha.c_str(), edgeAlpha.c_str());
break;
}
default:
SkFAIL("Shouldn't get here");
}
fragBuilder->codeAppendf("%s = vec4(%s);", args.fOutputCoverage, edgeAlpha.c_str());
}
void GrGLBicubicEffect::emitCode(EmitArgs& args) {
const GrTextureDomain& domain = args.fFp.cast<GrBicubicEffect>().domain();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fCoefficientsUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kMat44f_GrSLType, kDefault_GrSLPrecision,
"Coefficients");
fImageIncrementUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"ImageIncrement");
const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni);
const char* coeff = uniformHandler->getUniformCStr(fCoefficientsUni);
SkString cubicBlendName;
static const GrGLSLShaderVar gCubicBlendArgs[] = {
GrGLSLShaderVar("coefficients", kMat44f_GrSLType),
GrGLSLShaderVar("t", kFloat_GrSLType),
GrGLSLShaderVar("c0", kVec4f_GrSLType),
GrGLSLShaderVar("c1", kVec4f_GrSLType),
GrGLSLShaderVar("c2", kVec4f_GrSLType),
GrGLSLShaderVar("c3", kVec4f_GrSLType),
};
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
fragBuilder->emitFunction(kVec4f_GrSLType,
"cubicBlend",
SK_ARRAY_COUNT(gCubicBlendArgs),
gCubicBlendArgs,
"\tvec4 ts = vec4(1.0, t, t * t, t * t * t);\n"
"\tvec4 c = coefficients * ts;\n"
"\treturn c.x * c0 + c.y * c1 + c.z * c2 + c.w * c3;\n",
&cubicBlendName);
fragBuilder->codeAppendf("\tvec2 coord = %s - %s * vec2(0.5);\n", coords2D.c_str(), imgInc);
// We unnormalize the coord in order to determine our fractional offset (f) within the texel
// We then snap coord to a texel center and renormalize. The snap prevents cases where the
// starting coords are near a texel boundary and accumulations of imgInc would cause us to skip/
// double hit a texel.
fragBuilder->codeAppendf("\tcoord /= %s;\n", imgInc);
fragBuilder->codeAppend("\tvec2 f = fract(coord);\n");
fragBuilder->codeAppendf("\tcoord = (coord - f + vec2(0.5)) * %s;\n", imgInc);
fragBuilder->codeAppend("\tvec4 rowColors[4];\n");
for (int y = 0; y < 4; ++y) {
for (int x = 0; x < 4; ++x) {
SkString coord;
coord.printf("coord + %s * vec2(%d, %d)", imgInc, x - 1, y - 1);
SkString sampleVar;
sampleVar.printf("rowColors[%d]", x);
fDomain.sampleTexture(fragBuilder,
args.fUniformHandler,
args.fGLSLCaps,
domain,
sampleVar.c_str(),
coord,
args.fTexSamplers[0]);
}
fragBuilder->codeAppendf(
"\tvec4 s%d = %s(%s, f.x, rowColors[0], rowColors[1], rowColors[2], rowColors[3]);\n",
y, cubicBlendName.c_str(), coeff);
}
SkString bicubicColor;
bicubicColor.printf("%s(%s, f.y, s0, s1, s2, s3)", cubicBlendName.c_str(), coeff);
fragBuilder->codeAppendf("\t%s = %s;\n",
args.fOutputColor, (GrGLSLExpr4(bicubicColor.c_str()) *
GrGLSLExpr4(args.fInputColor)).c_str());
}
void GrGLBicubicEffect::emitCode(EmitArgs& args) {
const GrBicubicEffect& bicubicEffect = args.fFp.cast<GrBicubicEffect>();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fImageIncrementUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"ImageIncrement");
const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni);
fColorSpaceHelper.emitCode(uniformHandler, bicubicEffect.colorSpaceXform());
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
/*
* Filter weights come from Don Mitchell & Arun Netravali's 'Reconstruction Filters in Computer
* Graphics', ACM SIGGRAPH Computer Graphics 22, 4 (Aug. 1988).
* ACM DL: http://dl.acm.org/citation.cfm?id=378514
* Free : http://www.cs.utexas.edu/users/fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf
*
* The authors define a family of cubic filters with two free parameters (B and C):
*
* { (12 - 9B - 6C)|x|^3 + (-18 + 12B + 6C)|x|^2 + (6 - 2B) if |x| < 1
* k(x) = 1/6 { (-B - 6C)|x|^3 + (6B + 30C)|x|^2 + (-12B - 48C)|x| + (8B + 24C) if 1 <= |x| < 2
* { 0 otherwise
*
* Various well-known cubic splines can be generated, and the authors select (1/3, 1/3) as their
* favorite overall spline - this is now commonly known as the Mitchell filter, and is the
* source of the specific weights below.
*
* This is GLSL, so the matrix is column-major (transposed from standard matrix notation).
*/
fragBuilder->codeAppend("mat4 kMitchellCoefficients = mat4("
" 1.0 / 18.0, 16.0 / 18.0, 1.0 / 18.0, 0.0 / 18.0,"
"-9.0 / 18.0, 0.0 / 18.0, 9.0 / 18.0, 0.0 / 18.0,"
"15.0 / 18.0, -36.0 / 18.0, 27.0 / 18.0, -6.0 / 18.0,"
"-7.0 / 18.0, 21.0 / 18.0, -21.0 / 18.0, 7.0 / 18.0);");
fragBuilder->codeAppendf("vec2 coord = %s - %s * vec2(0.5);", coords2D.c_str(), imgInc);
// We unnormalize the coord in order to determine our fractional offset (f) within the texel
// We then snap coord to a texel center and renormalize. The snap prevents cases where the
// starting coords are near a texel boundary and accumulations of imgInc would cause us to skip/
// double hit a texel.
fragBuilder->codeAppendf("coord /= %s;", imgInc);
fragBuilder->codeAppend("vec2 f = fract(coord);");
fragBuilder->codeAppendf("coord = (coord - f + vec2(0.5)) * %s;", imgInc);
fragBuilder->codeAppend("vec4 wx = kMitchellCoefficients * vec4(1.0, f.x, f.x * f.x, f.x * f.x * f.x);");
fragBuilder->codeAppend("vec4 wy = kMitchellCoefficients * vec4(1.0, f.y, f.y * f.y, f.y * f.y * f.y);");
fragBuilder->codeAppend("vec4 rowColors[4];");
for (int y = 0; y < 4; ++y) {
for (int x = 0; x < 4; ++x) {
SkString coord;
coord.printf("coord + %s * vec2(%d, %d)", imgInc, x - 1, y - 1);
SkString sampleVar;
sampleVar.printf("rowColors[%d]", x);
fDomain.sampleTexture(fragBuilder,
args.fUniformHandler,
args.fShaderCaps,
bicubicEffect.domain(),
sampleVar.c_str(),
coord,
args.fTexSamplers[0]);
}
fragBuilder->codeAppendf(
"vec4 s%d = wx.x * rowColors[0] + wx.y * rowColors[1] + wx.z * rowColors[2] + wx.w * rowColors[3];",
y);
}
SkString bicubicColor("(wy.x * s0 + wy.y * s1 + wy.z * s2 + wy.w * s3)");
if (fColorSpaceHelper.isValid()) {
SkString xformedColor;
fragBuilder->appendColorGamutXform(&xformedColor, bicubicColor.c_str(), &fColorSpaceHelper);
bicubicColor.swap(xformedColor);
}
fragBuilder->codeAppendf("%s = %s * %s;", args.fOutputColor, bicubicColor.c_str(),
args.fInputColor);
}
void GrGLMatrixConvolutionEffect::emitCode(EmitArgs& args) {
const GrMatrixConvolutionEffect& mce = args.fFp.cast<GrMatrixConvolutionEffect>();
const GrTextureDomain& domain = mce.domain();
int kWidth = mce.kernelSize().width();
int kHeight = mce.kernelSize().height();
int arrayCount = (kWidth * kHeight + 3) / 4;
SkASSERT(4 * arrayCount >= kWidth * kHeight);
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fImageIncrementUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType,
"ImageIncrement");
fKernelUni = uniformHandler->addUniformArray(kFragment_GrShaderFlag, kHalf4_GrSLType,
"Kernel",
arrayCount);
fKernelOffsetUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType,
"KernelOffset");
fGainUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf_GrSLType, "Gain");
fBiasUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf_GrSLType, "Bias");
const char* kernelOffset = uniformHandler->getUniformCStr(fKernelOffsetUni);
const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni);
const char* kernel = uniformHandler->getUniformCStr(fKernelUni);
const char* gain = uniformHandler->getUniformCStr(fGainUni);
const char* bias = uniformHandler->getUniformCStr(fBiasUni);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
fragBuilder->codeAppend("half4 sum = half4(0, 0, 0, 0);");
fragBuilder->codeAppendf("float2 coord = %s - %s * %s;", coords2D.c_str(), kernelOffset, imgInc);
fragBuilder->codeAppend("half4 c;");
const char* kVecSuffix[4] = { ".x", ".y", ".z", ".w" };
for (int y = 0; y < kHeight; y++) {
for (int x = 0; x < kWidth; x++) {
GrGLSLShaderBuilder::ShaderBlock block(fragBuilder);
int offset = y*kWidth + x;
fragBuilder->codeAppendf("half k = %s[%d]%s;", kernel, offset / 4,
kVecSuffix[offset & 0x3]);
SkString coord;
coord.printf("coord + half2(%d, %d) * %s", x, y, imgInc);
fDomain.sampleTexture(fragBuilder,
uniformHandler,
args.fShaderCaps,
domain,
"c",
coord,
args.fTexSamplers[0]);
if (!mce.convolveAlpha()) {
fragBuilder->codeAppend("c.rgb /= c.a;");
fragBuilder->codeAppend("c.rgb = clamp(c.rgb, 0.0, 1.0);");
}
fragBuilder->codeAppend("sum += c * k;");
}
}
if (mce.convolveAlpha()) {
fragBuilder->codeAppendf("%s = sum * %s + %s;", args.fOutputColor, gain, bias);
fragBuilder->codeAppendf("%s.a = clamp(%s.a, 0, 1);", args.fOutputColor, args.fOutputColor);
fragBuilder->codeAppendf("%s.rgb = clamp(%s.rgb, 0.0, %s.a);",
args.fOutputColor, args.fOutputColor, args.fOutputColor);
} else {
fDomain.sampleTexture(fragBuilder,
uniformHandler,
args.fShaderCaps,
domain,
"c",
coords2D,
args.fTexSamplers[0]);
fragBuilder->codeAppendf("%s.a = c.a;", args.fOutputColor);
fragBuilder->codeAppendf("%s.rgb = clamp(sum.rgb * %s + %s, 0, 1);", args.fOutputColor, gain, bias);
fragBuilder->codeAppendf("%s.rgb *= %s.a;", args.fOutputColor, args.fOutputColor);
}
fragBuilder->codeAppendf("%s *= %s;\n", args.fOutputColor, args.fInputColor);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldA8TextGeoProc& dfTexEffect =
args.fGP.cast<GrDistanceFieldA8TextGeoProc>();
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
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
if (!dfTexEffect.colorIgnored()) {
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.fTransformsIn,
args.fTransformsOut);
// 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);
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.numTextures() == 1);
GrTexture* atlas = dfTexEffect.textureAccess(0).getTexture();
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->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
fragBuilder->codeAppendf("vec2 uv = %s;\n", uv.fsIn());
fragBuilder->codeAppend("\tfloat texColor = ");
fragBuilder->appendTextureLookup(args.fSamplers[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.
// 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
fragBuilder->codeAppendf("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(%s.y));",
st.fsIn());
} 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
fragBuilder->codeAppendf("float st_grad_len = length(dFdy(%s));", st.fsIn());
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);");
}
fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
}
void GrGLQuadEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
const GrQuadEffect& gp = args.fGP.cast<GrQuadEffect>();
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(gp);
GrGLSLVertToFrag v(kVec4f_GrSLType);
varyingHandler->addVarying("HairQuadEdge", &v);
vertBuilder->codeAppendf("%s = %s;", v.vsOut(), gp.inHairQuadEdge()->fName);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup pass through color
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor, &fColorUniform);
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
gp.inPosition()->fName,
gp.viewMatrix(),
&fViewMatrixUniform);
// emit transforms with position
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
gp.inPosition()->fName,
gp.localMatrix(),
args.fFPCoordTransformHandler);
fragBuilder->codeAppendf("float edgeAlpha;");
switch (fEdgeType) {
case kHairlineAA_GrProcessorEdgeType: {
fragBuilder->codeAppendf("vec2 duvdx = dFdx(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 duvdy = dFdy(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 gF = vec2(2.0 * %s.x * duvdx.x - duvdx.y,"
" 2.0 * %s.x * duvdy.x - duvdy.y);",
v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("edgeAlpha = (%s.x * %s.x - %s.y);",
v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppend("edgeAlpha = sqrt(edgeAlpha * edgeAlpha / dot(gF, gF));");
fragBuilder->codeAppend("edgeAlpha = max(1.0 - edgeAlpha, 0.0);");
// Add line below for smooth cubic ramp
// fragBuilder->codeAppend("edgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);");
break;
}
case kFillAA_GrProcessorEdgeType: {
fragBuilder->codeAppendf("vec2 duvdx = dFdx(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 duvdy = dFdy(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 gF = vec2(2.0 * %s.x * duvdx.x - duvdx.y,"
" 2.0 * %s.x * duvdy.x - duvdy.y);",
v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("edgeAlpha = (%s.x * %s.x - %s.y);",
v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppend("edgeAlpha = edgeAlpha / sqrt(dot(gF, gF));");
fragBuilder->codeAppend("edgeAlpha = clamp(0.5 - edgeAlpha, 0.0, 1.0);");
// Add line below for smooth cubic ramp
// fragBuilder->codeAppend("edgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);");
break;
}
case kFillBW_GrProcessorEdgeType: {
fragBuilder->codeAppendf("edgeAlpha = (%s.x * %s.x - %s.y);",
v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppend("edgeAlpha = float(edgeAlpha < 0.0);");
break;
}
default:
SkFAIL("Shouldn't get here");
}
if (0xff != gp.coverageScale()) {
const char* coverageScale;
fCoverageScaleUniform = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType,
kDefault_GrSLPrecision,
"Coverage",
&coverageScale);
fragBuilder->codeAppendf("%s = vec4(%s * edgeAlpha);", args.fOutputCoverage, coverageScale);
} else {
fragBuilder->codeAppendf("%s = vec4(edgeAlpha);", args.fOutputCoverage);
}
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const DefaultGeoProc& gp = args.fGP.cast<DefaultGeoProc>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(gp);
// Setup pass through color
if (!gp.colorIgnored()) {
if (gp.hasVertexColor()) {
varyingHandler->addPassThroughAttribute(gp.inColor(), args.fOutputColor);
} else {
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor,
&fColorUniform);
}
}
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
gp.inPosition()->fName,
gp.viewMatrix(),
&fViewMatrixUniform);
if (gp.hasExplicitLocalCoords()) {
// emit transforms with explicit local coords
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
gp.inLocalCoords()->fName,
gp.localMatrix(),
args.fTransformsIn,
args.fTransformsOut);
} else if(gp.hasTransformedLocalCoords()) {
// transforms have already been applied to vertex attributes on the cpu
this->emitTransforms(vertBuilder,
varyingHandler,
gp.inLocalCoords()->fName,
args.fTransformsIn,
args.fTransformsOut);
} else {
// emit transforms with position
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
gp.inPosition()->fName,
gp.localMatrix(),
args.fTransformsIn,
args.fTransformsOut);
}
// Setup coverage as pass through
if (!gp.coverageWillBeIgnored()) {
if (gp.hasVertexCoverage()) {
fragBuilder->codeAppendf("float alpha = 1.0;");
varyingHandler->addPassThroughAttribute(gp.inCoverage(), "alpha");
fragBuilder->codeAppendf("%s = vec4(alpha);", args.fOutputCoverage);
} else if (gp.coverage() == 0xff) {
fragBuilder->codeAppendf("%s = vec4(1);", args.fOutputCoverage);
} else {
const char* fragCoverage;
fCoverageUniform = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType,
kDefault_GrSLPrecision,
"Coverage",
&fragCoverage);
fragBuilder->codeAppendf("%s = vec4(%s);", args.fOutputCoverage, fragCoverage);
}
}
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldPathGeoProc& dfTexEffect = args.fGP.cast<GrDistanceFieldPathGeoProc>();
GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
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
if (!dfTexEffect.colorIgnored()) {
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.fTransformsIn,
args.fTransformsOut);
const char* textureSizeUniName = nullptr;
fTextureSizeUni = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"TextureSize", &textureSizeUniName);
// Use highp to work around aliasing issues
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
fragBuilder->codeAppendf("vec2 uv = %s;", v.fsIn());
fragBuilder->codeAppend("float texColor = ");
fragBuilder->appendTextureLookup(args.fSamplers[0],
"uv",
kVec2f_GrSLType);
fragBuilder->codeAppend(".r;");
fragBuilder->codeAppend("float distance = "
SK_DistanceFieldMultiplier "*(texColor - " SK_DistanceFieldThreshold ");");
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
fragBuilder->codeAppendf("vec2 st = uv*%s;", textureSizeUniName);
fragBuilder->codeAppend("float afwidth;");
if (dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag) {
// For uniform scale, 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 = abs(" SK_DistanceFieldAAFactor "*dFdy(st.y));");
} 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);");
}
fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
}
void GrGLMorphologyEffect::emitCode(EmitArgs& args) {
const GrMorphologyEffect& me = args.fFp.cast<GrMorphologyEffect>();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fPixelSizeUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kDefault_GrSLPrecision,
"PixelSize");
const char* pixelSizeInc = uniformHandler->getUniformCStr(fPixelSizeUni);
fRangeUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"Range");
const char* range = uniformHandler->getUniformCStr(fRangeUni);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
const char* func;
switch (me.type()) {
case GrMorphologyEffect::kErode_MorphologyType:
fragBuilder->codeAppendf("\t\t%s = vec4(1, 1, 1, 1);\n", args.fOutputColor);
func = "min";
break;
case GrMorphologyEffect::kDilate_MorphologyType:
fragBuilder->codeAppendf("\t\t%s = vec4(0, 0, 0, 0);\n", args.fOutputColor);
func = "max";
break;
default:
SkFAIL("Unexpected type");
func = ""; // suppress warning
break;
}
const char* dir;
switch (me.direction()) {
case Gr1DKernelEffect::kX_Direction:
dir = "x";
break;
case Gr1DKernelEffect::kY_Direction:
dir = "y";
break;
default:
SkFAIL("Unknown filter direction.");
dir = ""; // suppress warning
}
int width = GrMorphologyEffect::WidthFromRadius(me.radius());
// vec2 coord = coord2D;
fragBuilder->codeAppendf("\t\tvec2 coord = %s;\n", coords2D.c_str());
// coord.x -= radius * pixelSize;
fragBuilder->codeAppendf("\t\tcoord.%s -= %d.0 * %s; \n", dir, me.radius(), pixelSizeInc);
if (me.useRange()) {
// highBound = min(highBound, coord.x + (width-1) * pixelSize);
fragBuilder->codeAppendf("\t\tfloat highBound = min(%s.y, coord.%s + %f * %s);",
range, dir, float(width - 1), pixelSizeInc);
// coord.x = max(lowBound, coord.x);
fragBuilder->codeAppendf("\t\tcoord.%s = max(%s.x, coord.%s);", dir, range, dir);
}
fragBuilder->codeAppendf("\t\tfor (int i = 0; i < %d; i++) {\n", width);
fragBuilder->codeAppendf("\t\t\t%s = %s(%s, ", args.fOutputColor, func, args.fOutputColor);
fragBuilder->appendTextureLookup(args.fTexSamplers[0], "coord");
fragBuilder->codeAppend(");\n");
// coord.x += pixelSize;
fragBuilder->codeAppendf("\t\t\tcoord.%s += %s;\n", dir, pixelSizeInc);
if (me.useRange()) {
// coord.x = min(highBound, coord.x);
fragBuilder->codeAppendf("\t\t\tcoord.%s = min(highBound, coord.%s);", dir, dir);
}
fragBuilder->codeAppend("\t\t}\n");
SkString modulate;
GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
fragBuilder->codeAppend(modulate.c_str());
}
void GLEllipticalRRectEffect::emitCode(EmitArgs& args) {
const EllipticalRRectEffect& erre = args.fFp.cast<EllipticalRRectEffect>();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
const char *rectName;
// The inner rect is the rrect bounds inset by the x/y radii
fInnerRectUniform = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf4_GrSLType,
"innerRect", &rectName);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
// At each quarter-ellipse corner we compute a vector that is the offset of the fragment pos
// to the ellipse center. The vector is pinned in x and y to be in the quarter-plane relevant
// to that corner. This means that points near the interior near the rrect top edge will have
// a vector that points straight up for both the TL left and TR corners. Computing an
// alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
// fragments near the other three edges will get the correct AA. Fragments in the interior of
// the rrect will have a (0,0) vector at all four corners. So long as the radii > 0.5 they will
// correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
//
// The code below is a simplified version of the above that performs maxs on the vector
// components before computing distances and alpha values so that only one distance computation
// need be computed to determine the min alpha.
fragBuilder->codeAppendf("float2 dxy0 = %s.xy - sk_FragCoord.xy;", rectName);
fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.zw;", rectName);
// If we're on a device where float != fp32 then we'll do the distance computation in a space
// that is normalized by the largest radius. The scale uniform will be scale, 1/scale. The
// radii uniform values are already in this normalized space.
const char* scaleName = nullptr;
if (!args.fShaderCaps->floatIs32Bits()) {
fScaleUniform = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType, "scale",
&scaleName);
}
// The uniforms with the inv squared radii are highp to prevent underflow.
switch (erre.getRRect().getType()) {
case SkRRect::kSimple_Type: {
const char *invRadiiXYSqdName;
fInvRadiiSqdUniform = uniformHandler->addUniform(kFragment_GrShaderFlag,
kHalf2_GrSLType,
"invRadiiXY",
&invRadiiXYSqdName);
fragBuilder->codeAppend("float2 dxy = max(max(dxy0, dxy1), 0.0);");
if (scaleName) {
fragBuilder->codeAppendf("dxy *= %s.y;", scaleName);
}
// Z is the x/y offsets divided by squared radii.
fragBuilder->codeAppendf("float2 Z = dxy * %s.xy;", invRadiiXYSqdName);
break;
}
case SkRRect::kNinePatch_Type: {
const char *invRadiiLTRBSqdName;
fInvRadiiSqdUniform = uniformHandler->addUniform(kFragment_GrShaderFlag,
kHalf4_GrSLType,
"invRadiiLTRB",
&invRadiiLTRBSqdName);
if (scaleName) {
fragBuilder->codeAppendf("dxy0 *= %s.y;", scaleName);
fragBuilder->codeAppendf("dxy1 *= %s.y;", scaleName);
}
fragBuilder->codeAppend("float2 dxy = max(max(dxy0, dxy1), 0.0);");
// Z is the x/y offsets divided by squared radii. We only care about the (at most) one
// corner where both the x and y offsets are positive, hence the maxes. (The inverse
// squared radii will always be positive.)
fragBuilder->codeAppendf("float2 Z = max(max(dxy0 * %s.xy, dxy1 * %s.zw), 0.0);",
invRadiiLTRBSqdName, invRadiiLTRBSqdName);
break;
}
default:
SK_ABORT("RRect should always be simple or nine-patch.");
}
// implicit is the evaluation of (x/a)^2 + (y/b)^2 - 1.
fragBuilder->codeAppend("float implicit = dot(Z, dxy) - 1.0;");
// grad_dot is the squared length of the gradient of the implicit.
fragBuilder->codeAppend("float grad_dot = 4.0 * dot(Z, Z);");
// avoid calling inversesqrt on zero.
fragBuilder->codeAppend("grad_dot = max(grad_dot, 1.0e-4);");
fragBuilder->codeAppend("float approx_dist = implicit * inversesqrt(grad_dot);");
if (scaleName) {
fragBuilder->codeAppendf("approx_dist *= %s.x;", scaleName);
}
if (GrClipEdgeType::kFillAA == erre.getEdgeType()) {
fragBuilder->codeAppend("half alpha = clamp(0.5 - approx_dist, 0.0, 1.0);");
} else {
fragBuilder->codeAppend("half alpha = clamp(0.5 + approx_dist, 0.0, 1.0);");
}
fragBuilder->codeAppendf("%s = %s * alpha;", args.fOutputColor, args.fInputColor);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const DefaultGeoProc& gp = args.fGP.cast<DefaultGeoProc>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(gp);
// Setup pass through color
if (gp.hasVertexColor()) {
GrGLSLVarying varying(kHalf4_GrSLType);
varyingHandler->addVarying("color", &varying);
// There are several optional steps to process the color. Start with the attribute:
vertBuilder->codeAppendf("half4 color = %s;", gp.inColor()->fName);
// Linearize
if (gp.linearizeColor()) {
SkString srgbFuncName;
static const GrShaderVar gSrgbArgs[] = {
GrShaderVar("x", kHalf_GrSLType),
};
vertBuilder->emitFunction(kHalf_GrSLType,
"srgb_to_linear",
SK_ARRAY_COUNT(gSrgbArgs),
gSrgbArgs,
"return (x <= 0.04045) ? (x / 12.92) "
": pow((x + 0.055) / 1.055, 2.4);",
&srgbFuncName);
vertBuilder->codeAppendf("color = half4(%s(%s.r), %s(%s.g), %s(%s.b), %s.a);",
srgbFuncName.c_str(), gp.inColor()->fName,
srgbFuncName.c_str(), gp.inColor()->fName,
srgbFuncName.c_str(), gp.inColor()->fName,
gp.inColor()->fName);
}
// For SkColor, do a red/blue swap and premul
if (gp.fFlags & kColorAttributeIsSkColor_GPFlag) {
vertBuilder->codeAppend("color = half4(color.a * color.bgr, color.a);");
}
// Do color-correction to destination gamut
if (gp.linearizeColor()) {
fColorSpaceHelper.emitCode(uniformHandler, gp.fColorSpaceXform.get(),
kVertex_GrShaderFlag);
if (fColorSpaceHelper.isValid()) {
SkString xformedColor;
vertBuilder->appendColorGamutXform(&xformedColor, "color",
&fColorSpaceHelper);
vertBuilder->codeAppendf("color = %s;", xformedColor.c_str());
}
}
vertBuilder->codeAppendf("%s = color;\n", varying.vsOut());
fragBuilder->codeAppendf("%s = %s;", args.fOutputColor, varying.fsIn());
} else {
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor,
&fColorUniform);
}
// Setup position
this->writeOutputPosition(vertBuilder,
uniformHandler,
gpArgs,
gp.inPosition()->fName,
gp.viewMatrix(),
&fViewMatrixUniform);
if (gp.hasExplicitLocalCoords()) {
// emit transforms with explicit local coords
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gp.inLocalCoords()->asShaderVar(),
gp.localMatrix(),
args.fFPCoordTransformHandler);
} else {
// emit transforms with position
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gp.inPosition()->asShaderVar(),
gp.localMatrix(),
args.fFPCoordTransformHandler);
}
// Setup coverage as pass through
if (gp.hasVertexCoverage()) {
fragBuilder->codeAppendf("half alpha = 1.0;");
varyingHandler->addPassThroughAttribute(gp.inCoverage(), "alpha");
fragBuilder->codeAppendf("%s = half4(alpha);", args.fOutputCoverage);
} else if (gp.coverage() == 0xff) {
fragBuilder->codeAppendf("%s = half4(1);", args.fOutputCoverage);
} else {
const char* fragCoverage;
fCoverageUniform = uniformHandler->addUniform(kFragment_GrShaderFlag,
kHalf_GrSLType,
"Coverage",
&fragCoverage);
fragBuilder->codeAppendf("%s = half4(%s);", args.fOutputCoverage, fragCoverage);
}
}
void GLSLPathProcessor::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
using InstanceAttribs = GrCCPRPathProcessor::InstanceAttribs;
const GrCCPRPathProcessor& proc = args.fGP.cast<GrCCPRPathProcessor>();
GrGLSLUniformHandler* uniHandler = args.fUniformHandler;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
const char* atlasAdjust;
fAtlasAdjustUniform = uniHandler->addUniform(
kVertex_GrShaderFlag,
kVec2f_GrSLType, kHigh_GrSLPrecision, "atlas_adjust", &atlasAdjust);
varyingHandler->emitAttributes(proc);
GrGLSLVertToFrag texcoord(kVec2f_GrSLType);
GrGLSLVertToFrag color(kVec4f_GrSLType);
varyingHandler->addVarying("texcoord", &texcoord, kHigh_GrSLPrecision);
varyingHandler->addFlatPassThroughAttribute(&proc.getInstanceAttrib(InstanceAttribs::kColor),
args.fOutputColor, kLow_GrSLPrecision);
// Vertex shader.
GrGLSLVertexBuilder* v = args.fVertBuilder;
// Find the intersections of (bloated) devBounds and devBounds45 in order to come up with an
// octagon that circumscribes the (bloated) path. A vertex is the intersection of two lines:
// one edge from the path's bounding box and one edge from its 45-degree bounding box.
v->codeAppendf("highp mat2 N = mat2(%s);", proc.getEdgeNormsAttrib().fName);
// N[0] is the normal for the edge we are intersecting from the regular bounding box, pointing
// out of the octagon.
v->codeAppendf("highp vec2 refpt = (min(N[0].x, N[0].y) < 0) ? %s.xy : %s.zw;",
proc.getInstanceAttrib(InstanceAttribs::kDevBounds).fName,
proc.getInstanceAttrib(InstanceAttribs::kDevBounds).fName);
v->codeAppendf("refpt += N[0] * %f;", kAABloatRadius); // bloat for AA.
// N[1] is the normal for the edge we are intersecting from the 45-degree bounding box, pointing
// out of the octagon.
v->codeAppendf("highp vec2 refpt45 = (N[1].x < 0) ? %s.xy : %s.zw;",
proc.getInstanceAttrib(InstanceAttribs::kDevBounds45).fName,
proc.getInstanceAttrib(InstanceAttribs::kDevBounds45).fName);
v->codeAppendf("refpt45 *= mat2(.5,.5,-.5,.5);"); // transform back to device space.
v->codeAppendf("refpt45 += N[1] * %f;", kAABloatRadius); // bloat for AA.
v->codeAppend ("highp vec2 K = vec2(dot(N[0], refpt), dot(N[1], refpt45));");
v->codeAppendf("highp vec2 octocoord = K * inverse(N);");
gpArgs->fPositionVar.set(kVec2f_GrSLType, "octocoord");
// Convert to atlas coordinates in order to do our texture lookup.
v->codeAppendf("highp vec2 atlascoord = octocoord + vec2(%s);",
proc.getInstanceAttrib(InstanceAttribs::kAtlasOffset).fName);
if (kTopLeft_GrSurfaceOrigin == proc.atlas()->origin()) {
v->codeAppendf("%s = atlascoord * %s;", texcoord.vsOut(), atlasAdjust);
} else {
SkASSERT(kBottomLeft_GrSurfaceOrigin == proc.atlas()->origin());
v->codeAppendf("%s = vec2(atlascoord.x * %s.x, 1 - atlascoord.y * %s.y);",
texcoord.vsOut(), atlasAdjust, atlasAdjust);
}
// Convert to (local) path cordinates.
v->codeAppendf("highp vec2 pathcoord = inverse(mat2(%s)) * (octocoord - %s);",
proc.getInstanceAttrib(InstanceAttribs::kViewMatrix).fName,
proc.getInstanceAttrib(InstanceAttribs::kViewTranslate).fName);
this->emitTransforms(v, varyingHandler, uniHandler, gpArgs->fPositionVar, "pathcoord",
args.fFPCoordTransformHandler);
// Fragment shader.
GrGLSLPPFragmentBuilder* f = args.fFragBuilder;
f->codeAppend ("mediump float coverage_count = ");
f->appendTextureLookup(args.fTexSamplers[0], texcoord.fsIn(), kVec2f_GrSLType);
f->codeAppend (".a;");
if (SkPath::kWinding_FillType == proc.fillType()) {
f->codeAppendf("%s = vec4(min(abs(coverage_count), 1));", args.fOutputCoverage);
} else {
SkASSERT(SkPath::kEvenOdd_FillType == proc.fillType());
f->codeAppend ("mediump float t = mod(abs(coverage_count), 2);");
f->codeAppendf("%s = vec4(1 - abs(t - 1));", args.fOutputCoverage);
}
}
void GrGLConicEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
const GrConicEffect& gp = args.fGP.cast<GrConicEffect>();
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(gp);
GrGLSLVertToFrag v(kVec4f_GrSLType);
varyingHandler->addVarying("ConicCoeffs", &v, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = %s;", v.vsOut(), gp.inConicCoeffs()->fName);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup pass through color
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor, &fColorUniform);
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
gp.inPosition()->fName,
gp.viewMatrix(),
&fViewMatrixUniform);
// emit transforms with position
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
gp.inPosition()->fName,
gp.localMatrix(),
args.fFPCoordTransformHandler);
// TODO: this precision check should actually be a check on the number of bits
// high and medium provide and the selection of the lowest level that suffices.
// Additionally we should assert that the upstream code only lets us get here if
// either high or medium provides the required number of bits.
GrSLPrecision precision = kHigh_GrSLPrecision;
const GrShaderCaps::PrecisionInfo& highP = args.fShaderCaps->getFloatShaderPrecisionInfo(
kFragment_GrShaderType,
kHigh_GrSLPrecision);
if (!highP.supported()) {
precision = kMedium_GrSLPrecision;
}
GrShaderVar edgeAlpha("edgeAlpha", kFloat_GrSLType, 0, precision);
GrShaderVar dklmdx("dklmdx", kVec3f_GrSLType, 0, precision);
GrShaderVar dklmdy("dklmdy", kVec3f_GrSLType, 0, precision);
GrShaderVar dfdx("dfdx", kFloat_GrSLType, 0, precision);
GrShaderVar dfdy("dfdy", kFloat_GrSLType, 0, precision);
GrShaderVar gF("gF", kVec2f_GrSLType, 0, precision);
GrShaderVar gFM("gFM", kFloat_GrSLType, 0, precision);
GrShaderVar func("func", kFloat_GrSLType, 0, precision);
fragBuilder->declAppend(edgeAlpha);
fragBuilder->declAppend(dklmdx);
fragBuilder->declAppend(dklmdy);
fragBuilder->declAppend(dfdx);
fragBuilder->declAppend(dfdy);
fragBuilder->declAppend(gF);
fragBuilder->declAppend(gFM);
fragBuilder->declAppend(func);
switch (fEdgeType) {
case kHairlineAA_GrProcessorEdgeType: {
fragBuilder->codeAppendf("%s = dFdx(%s.xyz);", dklmdx.c_str(), v.fsIn());
fragBuilder->codeAppendf("%s = dFdy(%s.xyz);", dklmdy.c_str(), v.fsIn());
fragBuilder->codeAppendf("%s = 2.0 * %s.x * %s.x - %s.y * %s.z - %s.z * %s.y;",
dfdx.c_str(),
v.fsIn(), dklmdx.c_str(),
v.fsIn(), dklmdx.c_str(),
v.fsIn(), dklmdx.c_str());
fragBuilder->codeAppendf("%s = 2.0 * %s.x * %s.x - %s.y * %s.z - %s.z * %s.y;",
dfdy.c_str(),
v.fsIn(), dklmdy.c_str(),
v.fsIn(), dklmdy.c_str(),
v.fsIn(), dklmdy.c_str());
fragBuilder->codeAppendf("%s = vec2(%s, %s);", gF.c_str(), dfdx.c_str(), dfdy.c_str());
fragBuilder->codeAppendf("%s = sqrt(dot(%s, %s));",
gFM.c_str(), gF.c_str(), gF.c_str());
fragBuilder->codeAppendf("%s = %s.x*%s.x - %s.y*%s.z;",
func.c_str(), v.fsIn(), v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("%s = abs(%s);", func.c_str(), func.c_str());
fragBuilder->codeAppendf("%s = %s / %s;",
edgeAlpha.c_str(), func.c_str(), gFM.c_str());
fragBuilder->codeAppendf("%s = max(1.0 - %s, 0.0);",
edgeAlpha.c_str(), edgeAlpha.c_str());
// Add line below for smooth cubic ramp
// fragBuilder->codeAppend("edgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);");
break;
}
case kFillAA_GrProcessorEdgeType: {
fragBuilder->codeAppendf("%s = dFdx(%s.xyz);", dklmdx.c_str(), v.fsIn());
fragBuilder->codeAppendf("%s = dFdy(%s.xyz);", dklmdy.c_str(), v.fsIn());
fragBuilder->codeAppendf("%s ="
"2.0 * %s.x * %s.x - %s.y * %s.z - %s.z * %s.y;",
dfdx.c_str(),
v.fsIn(), dklmdx.c_str(),
v.fsIn(), dklmdx.c_str(),
v.fsIn(), dklmdx.c_str());
fragBuilder->codeAppendf("%s ="
"2.0 * %s.x * %s.x - %s.y * %s.z - %s.z * %s.y;",
dfdy.c_str(),
v.fsIn(), dklmdy.c_str(),
v.fsIn(), dklmdy.c_str(),
v.fsIn(), dklmdy.c_str());
fragBuilder->codeAppendf("%s = vec2(%s, %s);", gF.c_str(), dfdx.c_str(), dfdy.c_str());
fragBuilder->codeAppendf("%s = sqrt(dot(%s, %s));",
gFM.c_str(), gF.c_str(), gF.c_str());
fragBuilder->codeAppendf("%s = %s.x * %s.x - %s.y * %s.z;",
func.c_str(), v.fsIn(), v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("%s = %s / %s;",
edgeAlpha.c_str(), func.c_str(), gFM.c_str());
fragBuilder->codeAppendf("%s = clamp(0.5 - %s, 0.0, 1.0);",
edgeAlpha.c_str(), edgeAlpha.c_str());
// Add line below for smooth cubic ramp
// fragBuilder->codeAppend("edgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);");
break;
}
case kFillBW_GrProcessorEdgeType: {
fragBuilder->codeAppendf("%s = %s.x * %s.x - %s.y * %s.z;",
edgeAlpha.c_str(), v.fsIn(), v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("%s = float(%s < 0.0);",
edgeAlpha.c_str(), edgeAlpha.c_str());
break;
}
default:
SkFAIL("Shouldn't get here");
}
// TODO should we really be doing this?
if (gp.coverageScale() != 0xff) {
const char* coverageScale;
fCoverageScaleUniform = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType,
kHigh_GrSLPrecision,
"Coverage",
&coverageScale);
fragBuilder->codeAppendf("%s = vec4(%s * %s);",
args.fOutputCoverage, coverageScale, edgeAlpha.c_str());
} else {
fragBuilder->codeAppendf("%s = vec4(%s);", args.fOutputCoverage, edgeAlpha.c_str());
}
}
void emitCode(EmitArgs& args) override {
const TwoPointConicalEffect& effect = args.fFp.cast<TwoPointConicalEffect>();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
this->emitUniforms(uniformHandler, effect);
fParamUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf2_GrSLType,
"Conical2FSParams");
SkString p0; // 1 / r1
SkString p1; // f = focalX = r0 / (r0 - r1)
p0.appendf("%s.x", uniformHandler->getUniformVariable(fParamUni).getName().c_str());
p1.appendf("%s.y", uniformHandler->getUniformVariable(fParamUni).getName().c_str());
const char* tName = "t"; // the gradient
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
const char* p = coords2D.c_str();
if (effect.isFocalOnCircle()) {
fragBuilder->codeAppendf("half x_t = dot(%s, %s) / %s.x;", p, p, p);
} else if (effect.isWellBehaved()) {
fragBuilder->codeAppendf("half x_t = length(%s) - %s.x * %s;", p, p, p0.c_str());
} else {
char sign = (effect.isSwapped() || !effect.isRadiusIncreasing()) ? '-' : ' ';
fragBuilder->codeAppendf("half temp = %s.x * %s.x - %s.y * %s.y;", p, p, p, p);
// Initialize x_t to illegal state
fragBuilder->codeAppendf("half x_t = -1;");
// Only do sqrt if temp >= 0; this is significantly slower than checking temp >= 0 in
// the if statement that checks r(t) >= 0. But GPU may break if we sqrt a negative
// float. (Although I havevn't observed that on any devices so far, and the old approach
// also does sqrt negative value without a check.) If the performance is really
// critical, maybe we should just compute the area where temp and x_t are always
// valid and drop all these ifs.
fragBuilder->codeAppendf("if (temp >= 0) {");
fragBuilder->codeAppendf("x_t = (%csqrt(temp) - %s.x * %s);", sign, p, p0.c_str());
fragBuilder->codeAppendf("}");
}
// empty sign is positive
char sign = effect.isRadiusIncreasing() ? ' ' : '-';
// "+ 0" is much faster than "+ p1" so we specialize the natively focal case where p1 = 0.
fragBuilder->codeAppendf("half %s = %cx_t + %s;", tName, sign,
effect.isNativelyFocal() ? "0" : p1.c_str());
if (!effect.isWellBehaved()) {
// output will default to transparent black (we simply won't write anything
// else to it if invalid, instead of discarding or returning prematurely)
fragBuilder->codeAppendf("%s = half4(0.0,0.0,0.0,0.0);", args.fOutputColor);
fragBuilder->codeAppendf("if (x_t > 0.0) {");
}
if (effect.isSwapped()) {
fragBuilder->codeAppendf("%s = 1 - %s;", tName, tName);
}
this->emitColor(fragBuilder,
uniformHandler,
args.fShaderCaps,
effect,
tName,
args.fOutputColor,
args.fInputColor,
args.fTexSamplers);
if (!effect.isWellBehaved()) {
fragBuilder->codeAppend("};");
}
}
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
if (!dfTexEffect.colorIgnored()) {
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.fTransformsIn,
args.fTransformsOut);
// set up varyings
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_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.numTextures() == 1);
GrTexture* atlas = dfTexEffect.textureAccess(0).getTexture();
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
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
// create LCD offset adjusted by inverse of transform
// Use highp to work around aliasing issues
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
fragBuilder->codeAppendf("vec2 uv = %s;\n", uv.fsIn());
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
SkScalar lcdDelta = 1.0f / (3.0f * atlas->width());
if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
fragBuilder->codeAppendf("float delta = -%.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
} else {
fragBuilder->codeAppendf("float delta = %.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
}
if (isUniformScale) {
fragBuilder->codeAppendf("float st_grad_len = abs(dFdy(%s.y));", st.fsIn());
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.
// 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("float st_grad_len = length(st_grad);");
fragBuilder->codeAppend("vec2 offset = delta*vec2(st_grad.y, -st_grad.x);");
} 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.fSamplers[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.fSamplers[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.fSamplers[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);");
}
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 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);
const char* atlasSizeInvName;
fAtlasSizeInvUniform = uniformHandler->addUniform(kVertex_GrShaderFlag,
kFloat2_GrSLType,
kHigh_GrSLPrecision,
"AtlasSizeInv",
&atlasSizeInvName);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
// setup pass through color
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
// Setup position
gpArgs->fPositionVar = dfTexEffect.inPosition()->asShaderVar();
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
dfTexEffect.inPosition()->asShaderVar(),
dfTexEffect.localMatrix(),
args.fFPCoordTransformHandler);
// set up varyings
GrGLSLVarying uv(kFloat2_GrSLType);
GrSLType texIdxType = args.fShaderCaps->integerSupport() ? kInt_GrSLType : kFloat_GrSLType;
GrGLSLVarying texIdx(texIdxType);
GrGLSLVarying st(kFloat2_GrSLType);
append_index_uv_varyings(args, dfTexEffect.inTextureCoords()->fName, atlasSizeInvName,
&uv, &texIdx, &st);
GrGLSLVarying delta(kFloat_GrSLType);
varyingHandler->addVarying("Delta", &delta);
if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
vertBuilder->codeAppendf("%s = -%s.x/3.0;", delta.vsOut(), atlasSizeInvName);
} else {
vertBuilder->codeAppendf("%s = %s.x/3.0;", delta.vsOut(), atlasSizeInvName);
}
// add frag shader code
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
bool isGammaCorrect =
SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
// create LCD offset adjusted by inverse of transform
// Use highp to work around aliasing issues
fragBuilder->codeAppendf("float2 uv = %s;\n", uv.fsIn());
if (isUniformScale) {
#ifdef SK_VULKAN
fragBuilder->codeAppendf("half 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("half st_grad_len = abs(dFdy(%s.y));", st.fsIn());
#endif
fragBuilder->codeAppendf("half2 offset = half2(st_grad_len*%s, 0.0);", delta.fsIn());
} 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("half2 st_grad = dFdx(%s);", st.fsIn());
fragBuilder->codeAppendf("half2 offset = %s*st_grad;", delta.fsIn());
#else
// We use dFdy because of a Mali 400 bug, and rotate -90 degrees to
// get the gradient in the x direction.
fragBuilder->codeAppendf("half2 st_grad = dFdy(%s);", st.fsIn());
fragBuilder->codeAppendf("half2 offset = %s*half2(st_grad.y, -st_grad.x);",
delta.fsIn());
#endif
fragBuilder->codeAppend("half st_grad_len = length(st_grad);");
} else {
fragBuilder->codeAppendf("half2 st = %s;\n", st.fsIn());
fragBuilder->codeAppend("half2 Jdx = dFdx(st);");
fragBuilder->codeAppend("half2 Jdy = dFdy(st);");
fragBuilder->codeAppendf("half2 offset = %s*Jdx;", delta.fsIn());
}
// sample the texture by index
fragBuilder->codeAppend("half4 texColor;");
append_multitexture_lookup(args, dfTexEffect.numTextureSamplers(),
texIdx, "uv", "texColor");
// green is distance to uv center
fragBuilder->codeAppend("half3 distance;");
fragBuilder->codeAppend("distance.y = texColor.r;");
// red is distance to left offset
fragBuilder->codeAppend("half2 uv_adjusted = uv - offset;");
append_multitexture_lookup(args, dfTexEffect.numTextureSamplers(),
texIdx, "uv_adjusted", "texColor");
fragBuilder->codeAppend("distance.x = texColor.r;");
// blue is distance to right offset
fragBuilder->codeAppend("uv_adjusted = uv + offset;");
append_multitexture_lookup(args, dfTexEffect.numTextureSamplers(),
texIdx, "uv_adjusted", "texColor");
fragBuilder->codeAppend("distance.z = texColor.r;");
fragBuilder->codeAppend("distance = "
"half3(" SK_DistanceFieldMultiplier ")*(distance - half3(" SK_DistanceFieldThreshold"));");
// adjust width based on gamma
const char* distanceAdjustUniName = nullptr;
fDistanceAdjustUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf3_GrSLType,
"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("half 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("half2 dist_grad = half2(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("half dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = half2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppend("half2 grad = half2(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->codeAppendf("%s = "
"half4(clamp((distance + half3(afwidth)) / half3(2.0 * afwidth), 0.0, 1.0), 1.0);",
args.fOutputCoverage);
} else {
fragBuilder->codeAppendf(
"%s = half4(smoothstep(half3(-afwidth), half3(afwidth), distance), 1.0);",
args.fOutputCoverage);
}
}
