compute initial winding from projected rays

src/pathops/SkPathOpsOp.cpp

Index: src/pathops/SkPathOpsOp.cpp
diff --git a/src/pathops/SkPathOpsOp.cpp b/src/pathops/SkPathOpsOp.cpp
index 1105af5d70093be99259c861787f607320614181..f9a4fa3ca6993027dbddabbb28555e5b5d9606eb 100644
--- a/src/pathops/SkPathOpsOp.cpp
+++ b/src/pathops/SkPathOpsOp.cpp
@@ -98,41 +98,17 @@ static SkOpSegment* findChaseOp(SkTDArray<SkOpSpanBase*>& chase, SkOpSpanBase**
     return NULL;
 }
 
-static bool bridgeOp(SkTDArray<SkOpContour* >& contourList, const SkPathOp op,
+static bool bridgeOp(SkOpContourHead* contourList, const SkPathOp op,
         const int xorMask, const int xorOpMask, SkPathWriter* simple, SkChunkAlloc* allocator) {
-    bool firstContour = true;
     bool unsortable = false;
-    bool topUnsortable = false;
-    bool firstPass = true;
-    SkDPoint lastTopLeft;
-    SkDPoint topLeft = {SK_ScalarMin, SK_ScalarMin};
     do {
-        SkOpSpanBase* start = NULL;
-        SkOpSpanBase* end = NULL;
-        bool topDone;
-        bool onlyVertical = false;
-        lastTopLeft = topLeft;
-        SkOpSegment* current = FindSortableTop(contourList, firstPass, SkOpAngle::kBinarySingle,
-                &firstContour, &start, &end, &topLeft, &topUnsortable, &topDone, &onlyVertical,
-                allocator);
-        if (!current) {
-            if ((!topUnsortable || firstPass) && !topDone) {
-                SkASSERT(topLeft.fX != SK_ScalarMin && topLeft.fY != SK_ScalarMin);
-                if (lastTopLeft.fX == SK_ScalarMin && lastTopLeft.fY == SK_ScalarMin) {
-                    if (firstPass) {
-                        firstPass = false;
-                    } else {
-                        break;
-                    }
-                }
-                topLeft.fX = topLeft.fY = SK_ScalarMin;
-                continue;
-            }
-            break;
-        } else if (onlyVertical) {
+        SkOpSpan* span = FindSortableTop(contourList);
+        if (!span) {
             break;
         }
-        firstPass = !topUnsortable || lastTopLeft != topLeft;
+        SkOpSegment* current = span->segment();
+        SkOpSpanBase* start = span->next();
+        SkOpSpanBase* end = span;
         SkTDArray<SkOpSpanBase*> chase;
         do {
             if (current->activeOp(start, end, xorMask, xorOpMask, op)) {
@@ -260,11 +236,13 @@ static void dump_op(const SkPath& one, const SkPath& two, SkPathOp op) {
 }
 #endif
 
-bool Op(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result) {
+bool OpDebug(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result,
+        bool expectSuccess) {
     SkChunkAlloc allocator(4096);  // FIXME: add a constant expression here, tune
     SkOpContour contour;
+    SkOpContourHead* contourList = static_cast<SkOpContourHead*>(&contour);
     SkOpCoincidence coincidence;
-    SkOpGlobalState globalState(&coincidence  SkDEBUGPARAMS(&contour));
+    SkOpGlobalState globalState(&coincidence, contourList);
 #if DEBUGGING_PATHOPS_FROM_HOST
     dump_op(one, two, op);
 #endif    
@@ -285,7 +263,7 @@ bool Op(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result) {
         subtrahend = &one;
         op = kDifference_SkPathOp;
     }
-#if DEBUG_SORT || DEBUG_SWAP_TOP
+#if DEBUG_SORT
     SkPathOpsDebug::gSortCount = SkPathOpsDebug::gSortCountDefault;
 #endif
     // turn path into list of segments
@@ -303,36 +281,24 @@ bool Op(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result) {
 #endif
 
     const int xorOpMask = builder.xorMask();
-    SkTDArray<SkOpContour* > contourList;
-    MakeContourList(&contour, contourList, xorMask == kEvenOdd_PathOpsMask,
-            xorOpMask == kEvenOdd_PathOpsMask);
-    SkOpContour** currentPtr = contourList.begin();
-    if (!currentPtr) {
+    if (!SortContourList(&contourList, xorMask == kEvenOdd_PathOpsMask,
+            xorOpMask == kEvenOdd_PathOpsMask)) {
         result->reset();
         result->setFillType(fillType);
         return true;
     }
-    if ((*currentPtr)->count() == 0) {
-        SkASSERT((*currentPtr)->next() == NULL);
-        result->reset();
-        result->setFillType(fillType);
-        return true;
-    }
-    SkOpContour** listEnd = contourList.end();
     // find all intersections between segments
+    SkOpContour* current = contourList;
     do {
-        SkOpContour** nextPtr = currentPtr;
-        SkOpContour* current = *currentPtr++;
-        SkOpContour* next;
-        do {
-            next = *nextPtr++;
-        } while (AddIntersectTs(current, next, &coincidence, &allocator) && nextPtr != listEnd);
-    } while (currentPtr != listEnd);
+        SkOpContour* next = current;
+        while (AddIntersectTs(current, next, &coincidence, &allocator)
+                && (next = next->next()))
+            ;
+    } while ((current = current->next()));
 #if DEBUG_VALIDATE
     globalState.setPhase(SkOpGlobalState::kWalking);
 #endif
-    // eat through coincident edges
-    if (!HandleCoincidence(&contourList, &coincidence, &allocator, &globalState)) {
+    if (!HandleCoincidence(contourList, &coincidence, &allocator)) {
         return false;
     }
     // construct closed contours
@@ -350,3 +316,7 @@ bool Op(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result) {
     }
     return true;
 }
+
+bool Op(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result) {
+    return OpDebug(one, two, op, result, true);
+}