deal more consistently with unsortable edges

Improve line/curve coincident detection and resolution. This fixed the remaining simple failures.

When an edge is unsortable, use the ray intersection to determine the angles' winding.

Deal with degenerate segments.

TBR=reed@google.com
BUG=skia:3588,skia:3762

Review URL: https://codereview.chromium.org/1140813002

1 files changed, 10 insertions, 0 deletions

diff --git a/src/pathops/SkOpSpan.cpp b/src/pathops/SkOpSpan.cpp
index 9c9e07f985..e89ec3e204 100755
--- a/src/pathops/SkOpSpan.cpp
+++ b/src/pathops/SkOpSpan.cpp
@@ -249,6 +249,16 @@ tryNextRemainder:
     fSpanAdds += span->fSpanAdds;
 }
 
+int SkOpSpan::computeWindSum() {
+    SkOpGlobalState* globals = this->globalState();
+    SkOpContour* contourHead = globals->contourHead();
+    int windTry = 0;
+    while (!this->sortableTop(contourHead) && ++windTry < SkOpGlobalState::kMaxWindingTries) {
+        ;
+    }
+    return this->windSum();
+}
+
 bool SkOpSpan::containsCoincidence(const SkOpSegment* segment) const {
     SkASSERT(this->segment() != segment);
     const SkOpSpan* next = fCoincident;