pathops coincidence and security rewrite

src/pathops/SkAddIntersections.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkAddIntersections.h"
 #include "SkOpCoincidence.h"
 #include "SkPathOpsBounds.h"
 
@@ skipping 236 matching lines @@
 
 static void debugShowCubicConicIntersection(int , const SkIntersectionHelper& ,
         const SkIntersectionHelper& , const SkIntersections& ) {
 }
 
 static void debugShowCubicIntersection(int , const SkIntersectionHelper& ,
         const SkIntersectionHelper& , const SkIntersections& ) {
 }
 #endif
 
-bool AddIntersectTs(SkOpContour* test, SkOpContour* next, SkOpCoincidence* coincidence,
-        SkChunkAlloc* allocator) {
+bool AddIntersectTs(SkOpContour* test, SkOpContour* next, SkOpCoincidence* coincidence) {
     if (test != next) {
         if (AlmostLessUlps(test->bounds().fBottom, next->bounds().fTop)) {
             return false;
         }
         // OPTIMIZATION: outset contour bounds a smidgen instead?
         if (!SkPathOpsBounds::Intersects(test->bounds(), next->bounds())) {
             return true;
         }
     }
     SkIntersectionHelper wt;
@@ skipping 230 matching lines @@
             }
 #if DEBUG_T_SECT_LOOP_COUNT
             test->globalState()->debugAddLoopCount(&ts, wt, wn);
 #endif
             int coinIndex = -1;
             SkOpPtT* coinPtT[2];
             for (int pt = 0; pt < pts; ++pt) {
                 SkASSERT(ts[0][pt] >= 0 && ts[0][pt] <= 1);
                 SkASSERT(ts[1][pt] >= 0 && ts[1][pt] <= 1);
                 wt.segment()->debugValidate();
-                SkOpPtT* testTAt = wt.segment()->addT(ts[swap][pt], SkOpSegment::kAllowAlias,
-                        allocator);
+                SkOpPtT* testTAt = wt.segment()->addT(ts[swap][pt], SkOpSegment::kAllowAliasMatch,
+                        nullptr);
                 wn.segment()->debugValidate();
-                SkOpPtT* nextTAt = wn.segment()->addT(ts[!swap][pt], SkOpSegment::kAllowAlias,
-                        allocator);
-                testTAt->addOpp(nextTAt);
+                SkOpPtT* nextTAt = wn.segment()->addT(ts[!swap][pt], SkOpSegment::kAllowAliasMatch,
+                        nullptr);
+                if (testTAt->addOpp(nextTAt)) {
+                    testTAt->span()->checkForCollapsedCoincidence();
+                }
                 if (testTAt->fPt != nextTAt->fPt) {
                     testTAt->span()->unaligned();
                     nextTAt->span()->unaligned();
                 }
                 wt.segment()->debugValidate();
                 wn.segment()->debugValidate();
                 if (!ts.isCoincident(pt)) {
                     continue;
                 }
                 if (coinIndex < 0) {
                     coinPtT[0] = testTAt;
                     coinPtT[1] = nextTAt;
                     coinIndex = pt;
                     continue;
                 }
                 if (coinPtT[0]->span() == testTAt->span()) {
                     coinIndex = -1;
                     continue;
                 }
                 if (coinPtT[1]->span() == nextTAt->span()) {
                     coinIndex = -1;  // coincidence span collapsed
                     continue;
                 }
                 if (swap) {
                     SkTSwap(coinPtT[0], coinPtT[1]);
                     SkTSwap(testTAt, nextTAt);
                 }
                 SkASSERT(coinPtT[0]->span()->t() < testTAt->span()->t());
-                coincidence->add(coinPtT[0], testTAt, coinPtT[1], nextTAt, allocator);
+                coincidence->add(coinPtT[0], testTAt, coinPtT[1], nextTAt);
                 wt.segment()->debugValidate();
                 wn.segment()->debugValidate();
                 coinIndex = -1;
             }
             SkASSERT(coinIndex < 0);  // expect coincidence to be paired
         } while (wn.advance());
     } while (wt.advance());
     return true;
 }