pathops version two

src/pathops/SkPathOpsTriangle.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 "SkPathOpsTriangle.h"
-
-// http://www.blackpawn.com/texts/pointinpoly/default.html
-// return true if pt is inside triangle; false if outside or on the line
-bool SkDTriangle::contains(const SkDPoint& pt) const {
-// Compute vectors
-    SkDVector v0 = fPts[2] - fPts[0];
-    SkDVector v1 = fPts[1] - fPts[0];
-    SkDVector v2 = pt - fPts[0];
-
-// Compute dot products
-    double dot00 = v0.dot(v0);
-    double dot01 = v0.dot(v1);
-    double dot02 = v0.dot(v2);
-    double dot11 = v1.dot(v1);
-    double dot12 = v1.dot(v2);
-
-// original code doesn't handle degenerate input; isn't symmetric with inclusion of corner pts;
-// introduces error with divide; doesn't short circuit on early answer
-#if 0
-// Compute barycentric coordinates
-    double invDenom = 1 / (dot00 * dot11 - dot01 * dot01);
-    double u = (dot11 * dot02 - dot01 * dot12) * invDenom;
-    double v = (dot00 * dot12 - dot01 * dot02) * invDenom;
-
-// Check if point is in triangle
-    return (u >= 0) && (v >= 0) && (u + v <= 1);
-#else
-    double w = dot00 * dot11 - dot01 * dot01;
-    if (w == 0) {
-        return false;
-    }
-    double wSign = w < 0 ? -1 : 1;
-    double u = (dot11 * dot02 - dot01 * dot12) * wSign;
-    if (u <= 0) {
-        return false;
-    }
-    double v = (dot00 * dot12 - dot01 * dot02) * wSign;
-    if (v <= 0) {
-        return false;
-    }
-    return u + v < w * wSign;
-#endif
-}