The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/gfx/skia/trunk/src/pathops/SkPathOpsTriangle.cpp	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,51 @@
     1.4 +/*
     1.5 + * Copyright 2012 Google Inc.
     1.6 + *
     1.7 + * Use of this source code is governed by a BSD-style license that can be
     1.8 + * found in the LICENSE file.
     1.9 + */
    1.10 +
    1.11 +#include "SkPathOpsTriangle.h"
    1.12 +
    1.13 +// http://www.blackpawn.com/texts/pointinpoly/default.html
    1.14 +// return true if pt is inside triangle; false if outside or on the line
    1.15 +bool SkDTriangle::contains(const SkDPoint& pt) const {
    1.16 +// Compute vectors
    1.17 +    SkDVector v0 = fPts[2] - fPts[0];
    1.18 +    SkDVector v1 = fPts[1] - fPts[0];
    1.19 +    SkDVector v2 = pt - fPts[0];
    1.20 +
    1.21 +// Compute dot products
    1.22 +    double dot00 = v0.dot(v0);
    1.23 +    double dot01 = v0.dot(v1);
    1.24 +    double dot02 = v0.dot(v2);
    1.25 +    double dot11 = v1.dot(v1);
    1.26 +    double dot12 = v1.dot(v2);
    1.27 +
    1.28 +// original code doesn't handle degenerate input; isn't symmetric with inclusion of corner pts;
    1.29 +// introduces necessary error with divide; doesn't short circuit on early answer
    1.30 +#if 0
    1.31 +// Compute barycentric coordinates
    1.32 +    double invDenom = 1 / (dot00 * dot11 - dot01 * dot01);
    1.33 +    double u = (dot11 * dot02 - dot01 * dot12) * invDenom;
    1.34 +    double v = (dot00 * dot12 - dot01 * dot02) * invDenom;
    1.35 +
    1.36 +// Check if point is in triangle
    1.37 +    return (u >= 0) && (v >= 0) && (u + v <= 1);
    1.38 +#else
    1.39 +    double w = dot00 * dot11 - dot01 * dot01;
    1.40 +    if (w == 0) {
    1.41 +        return false;
    1.42 +    }
    1.43 +    double wSign = w < 0 ? -1 : 1;
    1.44 +    double u = (dot11 * dot02 - dot01 * dot12) * wSign;
    1.45 +    if (u <= 0) {
    1.46 +        return false;
    1.47 +    }
    1.48 +    double v = (dot00 * dot12 - dot01 * dot02) * wSign;
    1.49 +    if (v <= 0) {
    1.50 +        return false;
    1.51 +    }
    1.52 +    return u + v < w * wSign;
    1.53 +#endif
    1.54 +}