pathops work in progress

src/pathops/SkDQuadLineIntersection.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 "SkIntersections.h"
 #include "SkPathOpsLine.h"
 #include "SkPathOpsQuad.h"
 
@@ skipping 123 matching lines @@
         A += C - 2 * B;  // A = a - 2*b + c
         B -= C;  // B = -(b - c)
         return SkDQuad::RootsValidT(A, 2 * B, C, roots);
     }
 
     int intersect() {
         addExactEndPoints();
         if (fAllowNear) {
             addNearEndPoints();
         }
-        double rootVals[2];
-        int roots = intersectRay(rootVals);
-        for (int index = 0; index < roots; ++index) {
-            double quadT = rootVals[index];
-            double lineT = findLineT(quadT);
-            SkDPoint pt;
-            if (pinTs(&quadT, &lineT, &pt, kPointUninitialized)) {
-                fIntersections->insert(quadT, lineT, pt);
+        if (fIntersections->used() == 2) {
+            // FIXME : need sharable code that turns spans into coincident if middle point is on
+        } else {
+            double rootVals[2];
+            int roots = intersectRay(rootVals);
+            for (int index = 0; index < roots; ++index) {
+                double quadT = rootVals[index];
+                double lineT = findLineT(quadT);
+                SkDPoint pt;
+                if (pinTs(&quadT, &lineT, &pt, kPointUninitialized)) {
+                    fIntersections->insert(quadT, lineT, pt);
+                }
             }
         }
         return fIntersections->used();
     }
 
     int horizontalIntersect(double axisIntercept, double roots[2]) {
         double D = fQuad[2].fY;  // f
         double E = fQuad[1].fY;  // e
         double F = fQuad[0].fY;  // d
         D += F - 2 * E;         // D = d - 2*e + f
@@ skipping 243 matching lines @@
 }
 
 int SkIntersections::intersectRay(const SkDQuad& quad, const SkDLine& line) {
     LineQuadraticIntersections q(quad, line, this);
     fUsed = q.intersectRay(fT[0]);
     for (int index = 0; index < fUsed; ++index) {
         fPt[index] = quad.ptAtT(fT[0][index]);
     }
     return fUsed;
 }