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);
}
static void add_pixelxor_code(GrGLSLFragmentBuilder* fragBuilder,
const char* srcColor,
const char* dstColor,
const char* outputColor,
const char* opColor) {
static const GrGLSLShaderVar gXorArgs[] = {
GrGLSLShaderVar("f1", kFloat_GrSLType),
GrGLSLShaderVar("f2", kFloat_GrSLType),
GrGLSLShaderVar("f3", kFloat_GrSLType),
GrGLSLShaderVar("fPowerOf2Divisor", kFloat_GrSLType),
};
SkString xorFuncName;
// The xor function checks if the three passed in floats (f1, f2, f3) would
// have a bit in the log2(fPowerOf2Divisor)-th position if they were
// represented by an int. It then performs an xor of the 3 bits (using
// the property that serial xors can be treated as a sum of 0s & 1s mod 2).
fragBuilder->emitFunction(kFloat_GrSLType,
"xor",
SK_ARRAY_COUNT(gXorArgs),
gXorArgs,
"float bit1 = floor(f1 / fPowerOf2Divisor);"
"float bit2 = floor(f2 / fPowerOf2Divisor);"
"float bit3 = floor(f3 / fPowerOf2Divisor);"
"return mod(bit1 + bit2 + bit3, 2.0);",
&xorFuncName);
fragBuilder->codeAppend("float red = 0.0, green = 0.0, blue = 0.0;");
if (srcColor) {
fragBuilder->codeAppendf("vec3 src = 255.99 * %s.rgb;", srcColor);
} else {
fragBuilder->codeAppendf("vec3 src = vec3(255.99);");
}
fragBuilder->codeAppendf("vec3 dst = 255.99 * %s.rgb;", dstColor);
fragBuilder->codeAppendf("vec3 op = 255.99 * %s;", opColor);
fragBuilder->codeAppend("float modValue = 128.0;");
fragBuilder->codeAppend("for (int i = 0; i < 8; i++) {");
fragBuilder->codeAppendf("float bit = %s(src.r, dst.r, op.r, modValue);", xorFuncName.c_str());
fragBuilder->codeAppend("red += modValue * bit;");
fragBuilder->codeAppend("src.r = mod(src.r, modValue);");
fragBuilder->codeAppend("dst.r = mod(dst.r, modValue);");
fragBuilder->codeAppend("op.r = mod(op.r, modValue);");
fragBuilder->codeAppendf("bit = %s(src.g, dst.g, op.g, modValue);", xorFuncName.c_str());
fragBuilder->codeAppend("green += modValue * bit;");
fragBuilder->codeAppend("src.g = mod(src.g, modValue);");
fragBuilder->codeAppend("dst.g = mod(dst.g, modValue);");
fragBuilder->codeAppend("op.g = mod(op.g, modValue);");
fragBuilder->codeAppendf("bit = %s(src.b, dst.b, op.b, modValue);", xorFuncName.c_str());
fragBuilder->codeAppend("blue += modValue * bit;");
fragBuilder->codeAppend("src.b = mod(src.b, modValue);");
fragBuilder->codeAppend("dst.b = mod(dst.b, modValue);");
fragBuilder->codeAppend("op.b = mod(op.b, modValue);");
fragBuilder->codeAppend("modValue /= 2.0;");
fragBuilder->codeAppend("}");
fragBuilder->codeAppendf("%s = vec4(red/255.0, green/255.0, blue/255.0, 1.0);", outputColor);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const PLSQuadEdgeEffect& qe = args.fGP.cast<PLSQuadEdgeEffect>();
GrGLSLVertexBuilder* vsBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(qe);
GrGLSLVertToFrag uv(kVec2f_GrSLType);
varyingHandler->addVarying("uv", &uv, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = %s;", uv.vsOut(), qe.inUV()->fName);
GrGLSLVertToFrag ep1(kVec2f_GrSLType);
varyingHandler->addVarying("endpoint1", &ep1, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);", ep1.vsOut(),
qe.inEndpoint1()->fName, qe.inEndpoint1()->fName);
GrGLSLVertToFrag ep2(kVec2f_GrSLType);
varyingHandler->addVarying("endpoint2", &ep2, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);", ep2.vsOut(),
qe.inEndpoint2()->fName, qe.inEndpoint2()->fName);
GrGLSLVertToFrag delta(kVec2f_GrSLType);
varyingHandler->addVarying("delta", &delta, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x - %s.x, %s.y - %s.y) * 0.5;",
delta.vsOut(), ep1.vsOut(), ep2.vsOut(), ep2.vsOut(),
ep1.vsOut());
GrGLSLVertToFrag windings(kInt_GrSLType);
varyingHandler->addFlatVarying("windings", &windings, kLow_GrSLPrecision);
vsBuilder->codeAppendf("%s = %s;",
windings.vsOut(), qe.inWindings()->fName);
// Setup position
this->setupPosition(vsBuilder, gpArgs, qe.inPosition()->fName);
// emit transforms
this->emitTransforms(vsBuilder, varyingHandler, uniformHandler, gpArgs->fPositionVar,
qe.inPosition()->fName, qe.localMatrix(), args.fTransformsIn,
args.fTransformsOut);
GrGLSLFragmentBuilder* fsBuilder = args.fFragBuilder;
SkAssertResult(fsBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kPixelLocalStorage_GLSLFeature));
SkAssertResult(fsBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
static const int QUAD_ARGS = 2;
GrGLSLShaderVar inQuadArgs[QUAD_ARGS] = {
GrGLSLShaderVar("dot", kFloat_GrSLType, 0, kHigh_GrSLPrecision),
GrGLSLShaderVar("uv", kVec2f_GrSLType, 0, kHigh_GrSLPrecision)
};
SkString inQuadName;
const char* inQuadCode = "if (uv.x * uv.x <= uv.y) {"
"return dot >= 0.0;"
"} else {"
"return false;"
"}";
fsBuilder->emitFunction(kBool_GrSLType, "in_quad", QUAD_ARGS, inQuadArgs, inQuadCode,
&inQuadName);
fsBuilder->declAppendf(GR_GL_PLS_PATH_DATA_DECL);
// keep the derivative instructions outside the conditional
fsBuilder->codeAppendf("highp vec2 uvdX = dFdx(%s);", uv.fsIn());
fsBuilder->codeAppendf("highp vec2 uvdY = dFdy(%s);", uv.fsIn());
fsBuilder->codeAppend("highp vec2 uvIncX = uvdX * 0.45 + uvdY * -0.1;");
fsBuilder->codeAppend("highp vec2 uvIncY = uvdX * 0.1 + uvdY * 0.55;");
fsBuilder->codeAppendf("highp vec2 uv = %s.xy - uvdX * 0.35 - uvdY * 0.25;",
uv.fsIn());
fsBuilder->codeAppendf("highp vec2 firstSample = %s.xy - vec2(0.25);",
fsBuilder->fragmentPosition());
fsBuilder->codeAppendf("highp float d = dot(%s, (firstSample - %s).yx) * 2.0;",
delta.fsIn(), ep1.fsIn());
fsBuilder->codeAppendf("pls.windings[0] += %s(d, uv) ? %s : 0;", inQuadName.c_str(),
windings.fsIn());
fsBuilder->codeAppend("uv += uvIncX;");
fsBuilder->codeAppendf("d += %s.x;", delta.fsIn());
fsBuilder->codeAppendf("pls.windings[1] += %s(d, uv) ? %s : 0;", inQuadName.c_str(),
windings.fsIn());
fsBuilder->codeAppend("uv += uvIncY;");
fsBuilder->codeAppendf("d += %s.y;", delta.fsIn());
fsBuilder->codeAppendf("pls.windings[2] += %s(d, uv) ? %s : 0;", inQuadName.c_str(),
windings.fsIn());
fsBuilder->codeAppend("uv -= uvIncX;");
fsBuilder->codeAppendf("d -= %s.x;", delta.fsIn());
fsBuilder->codeAppendf("pls.windings[3] += %s(d, uv) ? %s : 0;", inQuadName.c_str(),
windings.fsIn());
}
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());
}