gfx/skia/trunk/src/pathops/SkPathOpsTriangle.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Sat, 03 Jan 2015 20:18:00 +0100
branch
TOR_BUG_3246
changeset 7
129ffea94266
permissions
-rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

     1 /*
     2  * Copyright 2012 Google Inc.
     3  *
     4  * Use of this source code is governed by a BSD-style license that can be
     5  * found in the LICENSE file.
     6  */
     8 #include "SkPathOpsTriangle.h"
    10 // http://www.blackpawn.com/texts/pointinpoly/default.html
    11 // return true if pt is inside triangle; false if outside or on the line
    12 bool SkDTriangle::contains(const SkDPoint& pt) const {
    13 // Compute vectors
    14     SkDVector v0 = fPts[2] - fPts[0];
    15     SkDVector v1 = fPts[1] - fPts[0];
    16     SkDVector v2 = pt - fPts[0];
    18 // Compute dot products
    19     double dot00 = v0.dot(v0);
    20     double dot01 = v0.dot(v1);
    21     double dot02 = v0.dot(v2);
    22     double dot11 = v1.dot(v1);
    23     double dot12 = v1.dot(v2);
    25 // original code doesn't handle degenerate input; isn't symmetric with inclusion of corner pts;
    26 // introduces necessary error with divide; doesn't short circuit on early answer
    27 #if 0
    28 // Compute barycentric coordinates
    29     double invDenom = 1 / (dot00 * dot11 - dot01 * dot01);
    30     double u = (dot11 * dot02 - dot01 * dot12) * invDenom;
    31     double v = (dot00 * dot12 - dot01 * dot02) * invDenom;
    33 // Check if point is in triangle
    34     return (u >= 0) && (v >= 0) && (u + v <= 1);
    35 #else
    36     double w = dot00 * dot11 - dot01 * dot01;
    37     if (w == 0) {
    38         return false;
    39     }
    40     double wSign = w < 0 ? -1 : 1;
    41     double u = (dot11 * dot02 - dot01 * dot12) * wSign;
    42     if (u <= 0) {
    43         return false;
    44     }
    45     double v = (dot00 * dot12 - dot01 * dot02) * wSign;
    46     if (v <= 0) {
    47         return false;
    48     }
    49     return u + v < w * wSign;
    50 #endif
    51 }

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