Added distance vector support for CircleGeometryProcessor
This CL's base is the CL that sets up the distance vector field req. exposure: https://codereview.chromium.org/2114993002/
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2190023002
Review-Url: https://codereview.chromium.org/2190023002
diff --git a/src/gpu/GrOvalRenderer.cpp b/src/gpu/GrOvalRenderer.cpp
index aec9b76..527b96e 100644
--- a/src/gpu/GrOvalRenderer.cpp
+++ b/src/gpu/GrOvalRenderer.cpp
@@ -83,10 +83,13 @@
fStroke = stroke;
}
+ bool implementsDistanceVector() const override { return true; };
+
const Attribute* inPosition() const { return fInPosition; }
const Attribute* inColor() const { return fInColor; }
const Attribute* inCircleEdge() const { return fInCircleEdge; }
const SkMatrix& localMatrix() const { return fLocalMatrix; }
+
virtual ~CircleGeometryProcessor() {}
const char* name() const override { return "CircleEdge"; }
@@ -126,14 +129,24 @@
args.fTransformsOut);
fragBuilder->codeAppendf("float d = length(%s.xy);", v.fsIn());
- fragBuilder->codeAppendf("float edgeAlpha = clamp(%s.z * (1.0 - d), 0.0, 1.0);",
- v.fsIn());
+ fragBuilder->codeAppendf("float distanceToEdge = %s.z * (1.0 - d);", v.fsIn());
+ fragBuilder->codeAppendf("float edgeAlpha = clamp(distanceToEdge, 0.0, 1.0);");
if (cgp.fStroke) {
fragBuilder->codeAppendf("float innerAlpha = clamp(%s.z * (d - %s.w), 0.0, 1.0);",
v.fsIn(), v.fsIn());
fragBuilder->codeAppend("edgeAlpha *= innerAlpha;");
}
+ if (args.fDistanceVectorName) {
+ fragBuilder->codeAppend ("if (d == 0.0) {"); // if on the center of the circle
+ fragBuilder->codeAppendf(" %s = vec2(distanceToEdge, 0.0);", // avoid normalizing
+ args.fDistanceVectorName);
+ fragBuilder->codeAppend ("} else {");
+ fragBuilder->codeAppendf(" %s = normalize(%s.xy) * distanceToEdge;",
+ args.fDistanceVectorName, v.fsIn());
+ fragBuilder->codeAppend ("}");
+ }
+
fragBuilder->codeAppendf("%s = vec4(edgeAlpha);", args.fOutputCoverage);
}