void GrGLVertexShaderBuilder::emitCodeBeforeEffects(GrGLSLExpr4* color, GrGLSLExpr4* coverage) {
const GrGLProgramDesc::KeyHeader& header = fProgramBuilder->desc().getHeader();
fPositionVar = &fInputs.push_back();
fPositionVar->set(kVec2f_GrSLType, GrGLShaderVar::kAttribute_TypeModifier, "inPosition");
if (-1 != header.fLocalCoordAttributeIndex) {
fLocalCoordsVar = &fInputs.push_back();
fLocalCoordsVar->set(kVec2f_GrSLType,
GrGLShaderVar::kAttribute_TypeModifier,
"inLocalCoords");
} else {
fLocalCoordsVar = fPositionVar;
}
const char* viewMName;
fProgramBuilder->fUniformHandles.fViewMatrixUni =
fProgramBuilder->addUniform(GrGLProgramBuilder::kVertex_Visibility,
kMat33f_GrSLType,
"ViewM",
&viewMName);
// Transform the position into Skia's device coords.
this->codeAppendf("vec3 pos3 = %s * vec3(%s, 1);",
viewMName, fPositionVar->c_str());
// we output point size in the GS if present
if (header.fEmitsPointSize
#if GR_GL_EXPERIMENTAL_GS
&& !header.fExperimentalGS
#endif
) {
this->codeAppend("gl_PointSize = 1.0;");
}
if (GrGLProgramDesc::kAttribute_ColorInput == header.fColorInput) {
this->addAttribute(GrShaderVar(color_attribute_name(),
kVec4f_GrSLType,
GrShaderVar::kAttribute_TypeModifier));
const char *vsName, *fsName;
fFullProgramBuilder->addVarying(kVec4f_GrSLType, "Color", &vsName, &fsName);
this->codeAppendf("%s = %s;", vsName, color_attribute_name());
*color = fsName;
}
if (GrGLProgramDesc::kAttribute_ColorInput == header.fCoverageInput) {
this->addAttribute(GrShaderVar(coverage_attribute_name(),
kVec4f_GrSLType,
GrShaderVar::kAttribute_TypeModifier));
const char *vsName, *fsName;
fFullProgramBuilder->addVarying(kVec4f_GrSLType, "Coverage", &vsName, &fsName);
this->codeAppendf("%s = %s;", vsName, coverage_attribute_name());
*coverage = fsName;
}
fEffectAttribOffset = fInputs.count();
}
void GrGLSLVaryingHandler::emitAttributes(const GrGeometryProcessor& gp) {
int vaCount = gp.numAttribs();
for (int i = 0; i < vaCount; i++) {
const GrGeometryProcessor::Attribute& attr = gp.getAttrib(i);
this->addAttribute(GrShaderVar(attr.fName,
GrVertexAttribTypeToSLType(attr.fType),
GrShaderVar::kAttribute_TypeModifier,
GrShaderVar::kNonArray,
attr.fPrecision));
}
}
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 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 GrShaderVar gPerlinNoiseArgs[] = {
GrShaderVar(chanCoord, kFloat_GrSLType),
GrShaderVar(noiseVec, kVec2f_GrSLType)
};
static const GrShaderVar gPerlinNoiseStitchArgs[] = {
GrShaderVar(chanCoord, kFloat_GrSLType),
GrShaderVar(noiseVec, kVec2f_GrSLType),
GrShaderVar(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);
}
