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 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 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 GrGLDisplacementMapEffect::emitCode(EmitArgs& args) {
const GrDisplacementMapEffect& displacementMap = args.fFp.cast<GrDisplacementMapEffect>();
const GrTextureDomain& domain = displacementMap.domain();
fScaleUni = args.fUniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision, "Scale");
const char* scaleUni = args.fUniformHandler->getUniformCStr(fScaleUni);
const char* dColor = "dColor";
const char* cCoords = "cCoords";
const char* nearZero = "1e-6"; // Since 6.10352e−5 is the smallest half float, use
// a number smaller than that to approximate 0, but
// leave room for 32-bit float GPU rounding errors.
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
fragBuilder->codeAppendf("\t\tvec4 %s = ", dColor);
fragBuilder->appendTextureLookup(args.fTexSamplers[0], args.fCoords[0].c_str(),
args.fCoords[0].getType());
fragBuilder->codeAppend(";\n");
// Unpremultiply the displacement
fragBuilder->codeAppendf(
"\t\t%s.rgb = (%s.a < %s) ? vec3(0.0) : clamp(%s.rgb / %s.a, 0.0, 1.0);",
dColor, dColor, nearZero, dColor, dColor);
SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 1);
fragBuilder->codeAppendf("\t\tvec2 %s = %s + %s*(%s.",
cCoords, coords2D.c_str(), scaleUni, dColor);
switch (displacementMap.xChannelSelector()) {
case SkDisplacementMapEffect::kR_ChannelSelectorType:
fragBuilder->codeAppend("r");
break;
case SkDisplacementMapEffect::kG_ChannelSelectorType:
fragBuilder->codeAppend("g");
break;
case SkDisplacementMapEffect::kB_ChannelSelectorType:
fragBuilder->codeAppend("b");
break;
case SkDisplacementMapEffect::kA_ChannelSelectorType:
fragBuilder->codeAppend("a");
break;
case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
default:
SkDEBUGFAIL("Unknown X channel selector");
}
switch (displacementMap.yChannelSelector()) {
case SkDisplacementMapEffect::kR_ChannelSelectorType:
fragBuilder->codeAppend("r");
break;
case SkDisplacementMapEffect::kG_ChannelSelectorType:
fragBuilder->codeAppend("g");
break;
case SkDisplacementMapEffect::kB_ChannelSelectorType:
fragBuilder->codeAppend("b");
break;
case SkDisplacementMapEffect::kA_ChannelSelectorType:
fragBuilder->codeAppend("a");
break;
case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
default:
SkDEBUGFAIL("Unknown Y channel selector");
}
fragBuilder->codeAppend("-vec2(0.5));\t\t");
fGLDomain.sampleTexture(fragBuilder,
args.fUniformHandler,
args.fGLSLCaps,
domain,
args.fOutputColor,
SkString(cCoords),
args.fTexSamplers[1]);
fragBuilder->codeAppend(";\n");
}
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 GrGLPerlinNoise::emitCode(EmitArgs& args) {
const GrPerlinNoiseEffect& pne = args.fFp.cast<GrPerlinNoiseEffect>();
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
SkString vCoords = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
fBaseFrequencyUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"baseFrequency");
const char* baseFrequencyUni = uniformHandler->getUniformCStr(fBaseFrequencyUni);
const char* stitchDataUni = nullptr;
if (pne.stitchTiles()) {
fStitchDataUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"stitchData");
stitchDataUni = uniformHandler->getUniformCStr(fStitchDataUni);
}
// There are 4 lines, so the center of each line is 1/8, 3/8, 5/8 and 7/8
const char* chanCoordR = "0.125";
const char* chanCoordG = "0.375";
const char* chanCoordB = "0.625";
const char* chanCoordA = "0.875";
const char* chanCoord = "chanCoord";
const char* stitchData = "stitchData";
const char* ratio = "ratio";
const char* noiseVec = "noiseVec";
const char* noiseSmooth = "noiseSmooth";
const char* floorVal = "floorVal";
const char* fractVal = "fractVal";
const char* uv = "uv";
const char* ab = "ab";
const char* latticeIdx = "latticeIdx";
const char* bcoords = "bcoords";
const char* lattice = "lattice";
const char* inc8bit = "0.00390625"; // 1.0 / 256.0
// This is the math to convert the two 16bit integer packed into rgba 8 bit input into a
// [-1,1] vector and perform a dot product between that vector and the provided vector.
const char* dotLattice = "dot(((%s.ga + %s.rb * vec2(%s)) * vec2(2.0) - vec2(1.0)), %s);";
// Add noise function
static const GrGLSLShaderVar gPerlinNoiseArgs[] = {
GrGLSLShaderVar(chanCoord, kFloat_GrSLType),
GrGLSLShaderVar(noiseVec, kVec2f_GrSLType)
};
static const GrGLSLShaderVar gPerlinNoiseStitchArgs[] = {
GrGLSLShaderVar(chanCoord, kFloat_GrSLType),
GrGLSLShaderVar(noiseVec, kVec2f_GrSLType),
GrGLSLShaderVar(stitchData, kVec2f_GrSLType)
};
SkString noiseCode;
noiseCode.appendf("\tvec4 %s;\n", floorVal);
noiseCode.appendf("\t%s.xy = floor(%s);\n", floorVal, noiseVec);
noiseCode.appendf("\t%s.zw = %s.xy + vec2(1.0);\n", floorVal, floorVal);
noiseCode.appendf("\tvec2 %s = fract(%s);\n", fractVal, noiseVec);
// smooth curve : t * t * (3 - 2 * t)
noiseCode.appendf("\n\tvec2 %s = %s * %s * (vec2(3.0) - vec2(2.0) * %s);",
noiseSmooth, fractVal, fractVal, fractVal);
// Adjust frequencies if we're stitching tiles
if (pne.stitchTiles()) {
noiseCode.appendf("\n\tif(%s.x >= %s.x) { %s.x -= %s.x; }",
floorVal, stitchData, floorVal, stitchData);
noiseCode.appendf("\n\tif(%s.y >= %s.y) { %s.y -= %s.y; }",
floorVal, stitchData, floorVal, stitchData);
noiseCode.appendf("\n\tif(%s.z >= %s.x) { %s.z -= %s.x; }",
floorVal, stitchData, floorVal, stitchData);
noiseCode.appendf("\n\tif(%s.w >= %s.y) { %s.w -= %s.y; }",
floorVal, stitchData, floorVal, stitchData);
}
// Get texture coordinates and normalize
noiseCode.appendf("\n\t%s = fract(floor(mod(%s, 256.0)) / vec4(256.0));\n",
floorVal, floorVal);
// Get permutation for x
{
SkString xCoords("");
xCoords.appendf("vec2(%s.x, 0.5)", floorVal);
noiseCode.appendf("\n\tvec2 %s;\n\t%s.x = ", latticeIdx, latticeIdx);
fragBuilder->appendTextureLookup(&noiseCode, args.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);
}