These tests stress pathops by describing the union of circle-like paths that have tiny line segments embedded and double back to create near-coincident conditions.
The fixes include
- detect when finding the active top loops between two possible answers
- preflight chasing winding to ensure answer is consistent
- binary search more often when quadratic intersection fails
- add more failure paths when an intersect is missed
While this fixes the chrome bug, reenabling path ops in svg should be deferred until additional fixes are landed.
TBR=
BUG=421132
Committed: https://skia.googlesource.com/skia/+/6f726addf3178b01949bb389ef83cf14a1d7b6b2
Review URL: https://codereview.chromium.org/633393002
diff --git a/src/pathops/SkOpContour.cpp b/src/pathops/SkOpContour.cpp
index 6d6ad79..28c072a 100644
--- a/src/pathops/SkOpContour.cpp
+++ b/src/pathops/SkOpContour.cpp
@@ -13,7 +13,7 @@
const SkIntersections& ts, bool swap) {
SkPoint pt0 = ts.pt(0).asSkPoint();
SkPoint pt1 = ts.pt(1).asSkPoint();
- if (pt0 == pt1) {
+ if (pt0 == pt1 || ts[0][0] == ts[0][1] || ts[1][0] == ts[1][1]) {
// FIXME: one could imagine a case where it would be incorrect to ignore this
// suppose two self-intersecting cubics overlap to be coincident --
// this needs to check that by some measure the t values are far enough apart