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);
GrGLSLPPFragmentBuilder* 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());
}
