path ops work in progress

src/pathops/SkDQuadIntersection.cpp

 // Another approach is to start with the implicit form of one curve and solve
 // (seek implicit coefficients in QuadraticParameter.cpp
 // by substituting in the parametric form of the other.
 // The downside of this approach is that early rejects are difficult to come by.
 // http://planetmath.org/encyclopedia/GaloisTheoreticDerivationOfTheQuarticFormula.html#step
 
 
 #include "SkDQuadImplicit.h"
 #include "SkIntersections.h"
 #include "SkPathOpsLine.h"
@@ skipping 373 matching lines @@
         if (swap) {
             i->insert(testT, impTs[0][index], tmpLine[0]);
         } else {
             i->insert(impTs[0][index], testT, tmpLine[0]);
         }
     }
 }
 
 int SkIntersections::intersect(const SkDQuad& q1, const SkDQuad& q2) {
     // if the quads share an end point, check to see if they overlap
-
     for (int i1 = 0; i1 < 3; i1 += 2) {
         for (int i2 = 0; i2 < 3; i2 += 2) {
-            if (q1[i1].approximatelyEqualHalf(q2[i2])) {
+            if (q1[i1] == q2[i2]) {
                 insert(i1 >> 1, i2 >> 1, q1[i1]);
             }
         }
     }
+    if (fAllowNear || true) {   // FIXME ? cubic/cubic intersection fails without (cubicOp67u)
+        for (int i1 = 0; i1 < 3; i1 += 2) {
+            for (int i2 = 0; i2 < 3; i2 += 2) {
+                if (q1[i1] != q2[i2] && q1[i1].approximatelyEqualHalf(q2[i2])) {
+                    insertNear(i1 >> 1, i2 >> 1, q1[i1]);
+                }
+            }
+        }
+    }
     SkASSERT(fUsed < 3);
     if (only_end_pts_in_common(q1, q2)) {
         return fUsed;
     }
     if (only_end_pts_in_common(q2, q1)) {
         return fUsed;
     }
     // see if either quad is really a line
     // FIXME: figure out why reduce step didn't find this earlier
     if (is_linear(q1, q2, this)) {
@@ skipping 130 matching lines @@
         }
         if (lowestIndex < 0) {
             break;
         }
         insert(roots1Copy[lowestIndex], roots2Copy[closest[lowestIndex]],
                 pts1[lowestIndex]);
         closest[lowestIndex] = -1;
     } while (++used < r1Count);
     return fUsed;
 }