pathops work in progress

src/pathops/SkDLineIntersection.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"
 
 /* Determine the intersection point of two lines. This assumes the lines are not parallel,
@@ skipping 163 matching lines @@
     if (min > y || max < y) {
         return 0;
     }
     if (AlmostEqualUlps(min, max) && max - min < fabs(line[0].fX - line[1].fX)) {
         return 2;
     }
     return 1;
 }
 
 static double horizontal_intercept(const SkDLine& line, double y) {
-     return (y - line[0].fY) / (line[1].fY - line[0].fY);
+     return SkPinT((y - line[0].fY) / (line[1].fY - line[0].fY));
 }
 
 int SkIntersections::horizontal(const SkDLine& line, double y) {
     fMax = 2;
     int horizontalType = horizontal_coincident(line, y);
     if (horizontalType == 1) {
         fT[0][0] = horizontal_intercept(line, y);
     } else if (horizontalType == 2) {
         fT[0][0] = 0;
         fT[0][1] = 1;
@@ skipping 65 matching lines @@
     if (!precisely_between(min, x, max)) {
         return 0;
     }
     if (AlmostEqualUlps(min, max)) {
         return 2;
     }
     return 1;
 }
 
 static double vertical_intercept(const SkDLine& line, double x) {
-    return (x - line[0].fX) / (line[1].fX - line[0].fX);
+    return SkPinT((x - line[0].fX) / (line[1].fX - line[0].fX));
 }
 
 int SkIntersections::vertical(const SkDLine& line, double x) {
     fMax = 2;
     int verticalType = vertical_coincident(line, x);
     if (verticalType == 1) {
         fT[0][0] = vertical_intercept(line, x);
     } else if (verticalType == 2) {
         fT[0][0] = 0;
         fT[0][1] = 1;
@@ skipping 60 matching lines @@
 // 4 subs, 2 muls, 1 cmp
 static bool ccw(const SkDPoint& A, const SkDPoint& B, const SkDPoint& C) {
     return (C.fY - A.fY) * (B.fX - A.fX) > (B.fY - A.fY) * (C.fX - A.fX);
 }
 
 // 16 subs, 8 muls, 6 cmps
 bool SkIntersections::Test(const SkDLine& a, const SkDLine& b) {
     return ccw(a[0], b[0], b[1]) != ccw(a[1], b[0], b[1])
             && ccw(a[0], a[1], b[0]) != ccw(a[0], a[1], b[1]);
 }