pathops coincidence and security rewrite

src/pathops/SkDConicLineIntersection.cpp

 /*
  * Copyright 2015 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 "SkPathOpsConic.h"
+#include "SkPathOpsCurve.h"
 #include "SkPathOpsLine.h"
 
 class LineConicIntersections {
 public:
     enum PinTPoint {
         kPointUninitialized,
         kPointInitialized
     };
 
     LineConicIntersections(const SkDConic& c, const SkDLine& l, SkIntersections* i)
@@ skipping 173 matching lines @@
             double conicT = (double) (cIndex >> 1);
             if (fIntersections->hasT(conicT)) {
                 continue;
             }
             double lineT = fLine->nearPoint(fConic[cIndex], nullptr);
             if (lineT < 0) {
                 continue;
             }
             fIntersections->insert(conicT, lineT, fConic[cIndex]);
         }
-        // FIXME: see if line end is nearly on conic
+        addLineNearEndPoints();
+    }
+
+    void addLineNearEndPoints() {
+        for (int lIndex = 0; lIndex < 2; ++lIndex) {
+            double lineT = (double) lIndex;
+            if (fIntersections->hasOppT(lineT)) {
+                continue;
+            }
+            double conicT = ((SkDCurve*) &fConic)->nearPoint(SkPath::kConic_Verb,
+                (*fLine)[lIndex], (*fLine)[!lIndex]);
+            if (conicT < 0) {
+                continue;
+            }
+            fIntersections->insert(conicT, lineT, (*fLine)[lIndex]);
+        }
     }
 
     void addExactHorizontalEndPoints(double left, double right, double y) {
         for (int cIndex = 0; cIndex < SkDConic::kPointCount; cIndex += SkDConic::kPointLast) {
             double lineT = SkDLine::ExactPointH(fConic[cIndex], left, right, y);
             if (lineT < 0) {
                 continue;
             }
             double conicT = (double) (cIndex >> 1);
             fIntersections->insert(conicT, lineT, fConic[cIndex]);
         }
     }
 
     void addNearHorizontalEndPoints(double left, double right, double y) {
         for (int cIndex = 0; cIndex < SkDConic::kPointCount; cIndex += SkDConic::kPointLast) {
             double conicT = (double) (cIndex >> 1);
             if (fIntersections->hasT(conicT)) {
                 continue;
             }
             double lineT = SkDLine::NearPointH(fConic[cIndex], left, right, y);
             if (lineT < 0) {
                 continue;
             }
             fIntersections->insert(conicT, lineT, fConic[cIndex]);
         }
-        // FIXME: see if line end is nearly on conic
+        addLineNearEndPoints();

[herb_g, 2016/07/18 15:13:38]

this->?

[caryclark, 2016/07/18 15:55:49]

Done.

     }
 
     void addExactVerticalEndPoints(double top, double bottom, double x) {
         for (int cIndex = 0; cIndex < SkDConic::kPointCount; cIndex += SkDConic::kPointLast) {
             double lineT = SkDLine::ExactPointV(fConic[cIndex], top, bottom, x);
             if (lineT < 0) {
                 continue;
             }
             double conicT = (double) (cIndex >> 1);
             fIntersections->insert(conicT, lineT, fConic[cIndex]);
         }
     }
 
     void addNearVerticalEndPoints(double top, double bottom, double x) {
         for (int cIndex = 0; cIndex < SkDConic::kPointCount; cIndex += SkDConic::kPointLast) {
             double conicT = (double) (cIndex >> 1);
             if (fIntersections->hasT(conicT)) {
                 continue;
             }
             double lineT = SkDLine::NearPointV(fConic[cIndex], top, bottom, x);
             if (lineT < 0) {
                 continue;
             }
             fIntersections->insert(conicT, lineT, fConic[cIndex]);
         }
-        // FIXME: see if line end is nearly on conic
+        addLineNearEndPoints();
     }
 
     double findLineT(double t) {
         SkDPoint xy = fConic.ptAtT(t);
         double dx = (*fLine)[1].fX - (*fLine)[0].fX;
         double dy = (*fLine)[1].fY - (*fLine)[0].fY;
         if (fabs(dx) > fabs(dy)) {
             return (xy.fX - (*fLine)[0].fX) / dx;
         }
         return (xy.fY - (*fLine)[0].fY) / dy;
@@ skipping 96 matching lines @@
 
 int SkIntersections::HorizontalIntercept(const SkDConic& conic, SkScalar y, double* roots) {
     LineConicIntersections c(conic);
     return c.horizontalIntersect(y, roots);
 }
 
 int SkIntersections::VerticalIntercept(const SkDConic& conic, SkScalar x, double* roots) {
     LineConicIntersections c(conic);
     return c.verticalIntersect(x, roots);
 }