KiCad PCB EDA Suite
polygon/poly2tri/common/utils.h
Go to the documentation of this file.
1 /*
2  * Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
3  * http://code.google.com/p/poly2tri/
4  *
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without modification,
8  * are permitted provided that the following conditions are met:
9  *
10  * * Redistributions of source code must retain the above copyright notice,
11  * this list of conditions and the following disclaimer.
12  * * Redistributions in binary form must reproduce the above copyright notice,
13  * this list of conditions and the following disclaimer in the documentation
14  * and/or other materials provided with the distribution.
15  * * Neither the name of Poly2Tri nor the names of its contributors may be
16  * used to endorse or promote products derived from this software without specific
17  * prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef UTILS_H
33 #define UTILS_H
34 
35 // Otherwise #defines like M_PI are undeclared under Visual Studio
36 #define _USE_MATH_DEFINES
37 
38 #include <exception>
39 #include <math.h>
40 
41 namespace p2t {
42 
43 const double PI_3div4 = 3 * M_PI / 4;
44 const double PI_div2 = 1.57079632679489661923;
45 const double EPSILON = 1e-12;
46 
48 
60 {
61  double detleft = (pa.x - pc.x) * (pb.y - pc.y);
62  double detright = (pa.y - pc.y) * (pb.x - pc.x);
63  double val = detleft - detright;
64  if (val > -EPSILON && val < EPSILON) {
65  return COLLINEAR;
66  } else if (val > 0) {
67  return CCW;
68  }
69  return CW;
70 }
71 
72 /*
73 bool InScanArea(Point& pa, Point& pb, Point& pc, Point& pd)
74 {
75  double pdx = pd.x;
76  double pdy = pd.y;
77  double adx = pa.x - pdx;
78  double ady = pa.y - pdy;
79  double bdx = pb.x - pdx;
80  double bdy = pb.y - pdy;
81 
82  double adxbdy = adx * bdy;
83  double bdxady = bdx * ady;
84  double oabd = adxbdy - bdxady;
85 
86  if (oabd <= EPSILON) {
87  return false;
88  }
89 
90  double cdx = pc.x - pdx;
91  double cdy = pc.y - pdy;
92 
93  double cdxady = cdx * ady;
94  double adxcdy = adx * cdy;
95  double ocad = cdxady - adxcdy;
96 
97  if (ocad <= EPSILON) {
98  return false;
99  }
100 
101  return true;
102 }
103 
104 */
105 
106 bool InScanArea(Point& pa, Point& pb, Point& pc, Point& pd)
107 {
108  double oadb = (pa.x - pb.x)*(pd.y - pb.y) - (pd.x - pb.x)*(pa.y - pb.y);
109  if (oadb >= -EPSILON) {
110  return false;
111  }
112 
113  double oadc = (pa.x - pc.x)*(pd.y - pc.y) - (pd.x - pc.x)*(pa.y - pc.y);
114  if (oadc <= EPSILON) {
115  return false;
116  }
117  return true;
118 }
119 
120 }
121 
122 #endif
123 
bool InScanArea(Point &pa, Point &pb, Point &pc, Point &pd)
const double PI_div2
double y
Definition: shapes.h:47
const double PI_3div4
double x
Definition: shapes.h:47
Orientation Orient2d(Point &pa, Point &pb, Point &pc)
Forumla to calculate signed area Positive if CCW Negative if CW 0 if collinear ...
const double EPSILON
Sweep-line, Constrained Delauney Triangulation (CDT) See: Domiter, V.
Definition: shapes.h:41