Revert "Revert "Fix rendering of drrects with small circular inner rrects.""

This reverts commit ec727c981dd7ed83e98c7713c2828c6ab144937b.

Change-Id: Id3164619016d58b2bcc0b8af606215653f553fce
Reviewed-on: https://skia-review.googlesource.com/79422
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 15 insertions, 1 deletions

diff --git a/src/gpu/effects/GrCircleEffect.fp b/src/gpu/effects/GrCircleEffect.fp
index fe959f8bc8..352e824b54 100644
--- a/src/gpu/effects/GrCircleEffect.fp
+++ b/src/gpu/effects/GrCircleEffect.fp
@@ -15,6 +15,18 @@ half prevRadius = -1;
 // fills and (..., radius - 0.5, 1 / (radius - 0.5)) for inverse fills.
 uniform half4 circle;
 
+@make {
+    static std::unique_ptr<GrFragmentProcessor> Make(GrClipEdgeType edgeType, SkPoint center,
+                                                     float radius) {
+        // A radius below half causes the implicit insetting done by this processor to become
+        // inverted. We could handle this case by making the processor code more complicated.
+        if (radius < .5f) {
+            return nullptr;
+        }
+        return std::unique_ptr<GrFragmentProcessor>(new GrCircleEffect(edgeType, center, radius));
+    }
+}
+
 @optimizationFlags { kCompatibleWithCoverageAsAlpha_OptimizationFlag }
 
 @setData(pdman) {
@@ -22,6 +34,8 @@ uniform half4 circle;
         SkScalar effectiveRadius = radius;
         if (GrProcessorEdgeTypeIsInverseFill((GrClipEdgeType) edgeType)) {
             effectiveRadius -= 0.5f;
+            // When the radius is 0.5 effectiveRadius is 0 which causes an inf * 0 in the shader.
+            effectiveRadius = SkTMax(0.001f, effectiveRadius);
         } else {
             effectiveRadius += 0.5f;
         }
@@ -58,7 +72,7 @@ void main() {
     SkPoint center;
     center.fX = testData->fRandom->nextRangeScalar(0.f, 1000.f);
     center.fY = testData->fRandom->nextRangeScalar(0.f, 1000.f);
-    SkScalar radius = testData->fRandom->nextRangeF(0.f, 1000.f);
+    SkScalar radius = testData->fRandom->nextRangeF(1.f, 1000.f);
     GrClipEdgeType et;
     do {
         et = (GrClipEdgeType) testData->fRandom->nextULessThan(kGrClipEdgeTypeCnt);