Drop draw in GrAAConvextPathRenderer if calculation of center of mass ends up in NaN

Bug: skia:7770
Change-Id: If27494f5df0b5d5ba037e1d21c06bff98019d2b0
Reviewed-on: https://skia-review.googlesource.com/118300
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/src/gpu/ops/GrAAConvexPathRenderer.cpp b/src/gpu/ops/GrAAConvexPathRenderer.cpp
index c238d102e4..8ca022263b 100644
--- a/src/gpu/ops/GrAAConvexPathRenderer.cpp
+++ b/src/gpu/ops/GrAAConvexPathRenderer.cpp
@@ -64,7 +64,7 @@ struct Segment {
 
 typedef SkTArray<Segment, true> SegmentArray;
 
-static void center_of_mass(const SegmentArray& segments, SkPoint* c) {
+static bool center_of_mass(const SegmentArray& segments, SkPoint* c) {
     SkScalar area = 0;
     SkPoint center = {0, 0};
     int count = segments.count();
@@ -111,15 +111,17 @@ static void center_of_mass(const SegmentArray& segments, SkPoint* c) {
         // undo the translate of p0 to the origin.
         *c = center + p0;
     }
-    SkASSERT(!SkScalarIsNaN(c->fX) && !SkScalarIsNaN(c->fY));
+    return !SkScalarIsNaN(c->fX) && !SkScalarIsNaN(c->fY);
 }
 
-static void compute_vectors(SegmentArray* segments,
+static bool compute_vectors(SegmentArray* segments,
                             SkPoint* fanPt,
                             SkPathPriv::FirstDirection dir,
                             int* vCount,
                             int* iCount) {
-    center_of_mass(*segments, fanPt);
+    if (!center_of_mass(*segments, fanPt)) {
+        return false;
+    }
     int count = segments->count();
 
     // Make the normals point towards the outside
@@ -167,6 +169,7 @@ static void compute_vectors(SegmentArray* segments,
         *vCount += 4;
         *iCount += 6;
     }
+    return true;
 }
 
 struct DegenerateTestData {
@@ -325,8 +328,7 @@ static bool get_segments(const SkPath& path,
                 if (degenerateData.isDegenerate()) {
                     return false;
                 } else {
-                    compute_vectors(segments, fanPt, dir, vCount, iCount);
-                    return true;
+                    return compute_vectors(segments, fanPt, dir, vCount, iCount);
                 }
             default:
                 break;