harden pathops for pathological test

src/pathops/SkIntersections.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkIntersections_DEFINE
 #define SkIntersections_DEFINE
 
 #include "SkPathOpsCubic.h"
 #include "SkPathOpsLine.h"
 #include "SkPathOpsPoint.h"
 #include "SkPathOpsQuad.h"
 
 class SkIntersections {
 public:
     SkIntersections()
         : fSwap(0)
+        , fFlatMeasure(false)
 #ifdef SK_DEBUG
         , fDepth(0)
 #endif
     {
         sk_bzero(fPt, sizeof(fPt));
         sk_bzero(fPt2, sizeof(fPt2));
         sk_bzero(fT, sizeof(fT));
         sk_bzero(fIsCoincident, sizeof(fIsCoincident));
         sk_bzero(fNearlySame, sizeof(fNearlySame));
         reset();
         fMax = 0;  // require that the caller set the max
     }
 
     class TArray {
     public:
         explicit TArray(const double ts[9]) : fTArray(ts) {}
         double operator[](int n) const {
             return fTArray[n];
         }
         const double* fTArray;
     };
     TArray operator[](int n) const { return TArray(fT[n]); }
 
+    void allowFlatMeasure(bool flatAllowed) {
+        fFlatMeasure = flatAllowed;
+    }
+
     void allowNear(bool nearAllowed) {
         fAllowNear = nearAllowed;
     }
 
     int cubic(const SkPoint a[4]) {
         SkDCubic cubic;
         cubic.set(a);
         fMax = 1;  // self intersect
         return intersect(cubic);
     }
@@ skipping 29 matching lines @@
         line.set(b);
         fMax = 3;
         return intersect(cubic, line);
     }
 
     int cubicQuad(const SkPoint a[4], const SkPoint b[3]) {
         SkDCubic cubic;
         cubic.set(a);
         SkDQuad quad;
         quad.set(b);
-        fMax = 6;
+        fMax = 7;
         return intersect(cubic, quad);
     }
 
+    bool flatMeasure() const {
+        return fFlatMeasure;
+    }
+
     bool hasT(double t) const {
         SkASSERT(t == 0 || t == 1);
         return fUsed > 0 && (t == 0 ? fT[0][0] == 0 : fT[0][fUsed - 1] == 1);
     }
 
     int insertSwap(double one, double two, const SkDPoint& pt) {
         if (fSwap) {
             return insert(two, one, pt);
         } else {
             return insert(one, two, pt);
@@ skipping 89 matching lines @@
 
     void swap() {
         fSwap ^= true;
     }
 
     void swapPts();
 
     bool swapped() const {
         return fSwap;
     }
-
+    
     int used() const {
         return fUsed;
     }
 
     void downDepth() {
         SkASSERT(--fDepth >= 0);
     }
 
     void upDepth() {
         SkASSERT(++fDepth < 16);
     }
 
+    void alignQuadPts(const SkPoint a[3], const SkPoint b[3]);
     void append(const SkIntersections& );
-    void cleanUpCoincidence();
+    int cleanUpCoincidence();
     int coincidentUsed() const;
     void cubicInsert(double one, double two, const SkDPoint& pt, const SkDCubic& c1,
                      const SkDCubic& c2);
     int cubicRay(const SkPoint pts[4], const SkDLine& line);
     void flip();
     int horizontal(const SkDLine&, double y);
     int horizontal(const SkDLine&, double left, double right, double y, bool flipped);
     int horizontal(const SkDQuad&, double left, double right, double y, bool flipped);
     int horizontal(const SkDQuad&, double left, double right, double y, double tRange[2]);
     int horizontal(const SkDCubic&, double y, double tRange[3]);
@@ skipping 46 matching lines @@
 
     SkDPoint fPt[9];  // FIXME: since scans store points as SkPoint, this should also
     SkDPoint fPt2[9];  // used by nearly same to store alternate intersection point
     double fT[2][9];
     uint16_t fIsCoincident[2];  // bit set for each curve's coincident T
     bool fNearlySame[2];  // true if end points nearly match
     unsigned char fUsed;
     unsigned char fMax;
     bool fAllowNear;
     bool fSwap;
+    bool fFlatMeasure;  // backwards-compatibility when cubics uses quad intersection
 #ifdef SK_DEBUG
     int fDepth;
 #endif
 };
 
 extern int (SkIntersections::* const CurveRay[])(const SkPoint[], const SkDLine& );
 extern int (SkIntersections::* const CurveVertical[])(const SkPoint[], SkScalar top, SkScalar bottom,
             SkScalar x, bool flipped);
 
 #endif