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

Review URL: https://codereview.chromium.org/633393002

1 files changed, 26 insertions, 4 deletions

diff --git a/tests/PathOpsDebug.cpp b/tests/PathOpsDebug.cpp
index 8ac38aaf6d..c4fbbfa695 100755
--- a/tests/PathOpsDebug.cpp
+++ b/tests/PathOpsDebug.cpp
@@ -19,6 +19,9 @@ inline void DebugDumpFloat(float x) {
     }
 }
 
+inline void DebugDumpHexFloat(float x) {
+    SkDebugf("SkBits2Float(0x%08x)", SkFloat2Bits(x));
+}
 
 #if DEBUG_SHOW_TEST_NAME
 
@@ -413,6 +416,17 @@ void SkDPoint::Dump(const SkPoint& pt) {
     SkDebugf("}");
 }
 
+void SkDPoint::DumpHex(const SkPoint& pt) {
+    SkDebugf("{");
+    DebugDumpHexFloat(pt.fX);
+    SkDebugf(", ");
+    DebugDumpHexFloat(pt.fY);
+    SkDebugf("}");
+}
+
+void SkDQuad::dump() const {
+    dumpComma("");
+}
 
 void SkDQuad::dumpComma(const char* comma) const {
     SkDebugf("{{");
@@ -425,10 +439,6 @@ void SkDQuad::dumpComma(const char* comma) const {
     SkDebugf("}}%s\n", comma ? comma : "");
 }
 
-void SkDQuad::dump() const {
-    dumpComma("");
-}
-
 void SkIntersectionHelper::dump() const {
     SkDPoint::Dump(pts()[0]);
     SkDPoint::Dump(pts()[1]);
@@ -492,6 +502,18 @@ void SkOpSegment::dumpPts() const {
     SkDebugf("}}\n");
 }
 
+void SkOpSegment::dumpHexPts() const {
+    int last = SkPathOpsVerbToPoints(fVerb);
+    SkDebugf("((SkOpSegment*) 0x%p) [%d] {{", this, debugID());
+    int index = 0;
+    do {
+        SkDPoint::DumpHex(fPts[index]);
+        SkDebugf(", ");
+    } while (++index < last);
+    SkDPoint::DumpHex(fPts[index]);
+    SkDebugf("}}\n");
+}
+
 void SkOpSegment::dumpDPts() const {
     int count = SkPathOpsVerbToPoints(fVerb);
     SkDebugf("((SkOpSegment*) 0x%p) [%d] {{", this, debugID());