1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef UTILS_H
#define UTILS_H
// Otherwise #defines like M_PI are undeclared under Visual Studio
#define _USE_MATH_DEFINES
#include <exception>
#include <math.h>
namespace p2t {
const double PI_3div4 = 3 * M_PI / 4;
const double PI_div2 = 1.57079632679489661923;
const double EPSILON = 1e-12;
enum Orientation {
CW, CCW, COLLINEAR
};
/**
* Forumla to calculate signed area<br>
* Positive if CCW<br>
* Negative if CW<br>
* 0 if collinear<br>
* <pre>
* A[P1,P2,P3] = (x1*y2 - y1*x2) + (x2*y3 - y2*x3) + (x3*y1 - y3*x1)
* = (x1-x3)*(y2-y3) - (y1-y3)*(x2-x3)
* </pre>
*/
Orientation Orient2d( Point& pa, Point& pb, Point& pc )
{
double detleft = (pa.x - pc.x) * (pb.y - pc.y);
double detright = (pa.y - pc.y) * (pb.x - pc.x);
double val = detleft - detright;
if( val > -EPSILON && val < EPSILON )
{
return COLLINEAR;
}
else if( val > 0 )
{
return CCW;
}
return CW;
}
/*
* bool InScanArea(Point& pa, Point& pb, Point& pc, Point& pd)
* {
* double pdx = pd.x;
* double pdy = pd.y;
* double adx = pa.x - pdx;
* double ady = pa.y - pdy;
* double bdx = pb.x - pdx;
* double bdy = pb.y - pdy;
*
* double adxbdy = adx * bdy;
* double bdxady = bdx * ady;
* double oabd = adxbdy - bdxady;
*
* if (oabd <= EPSILON) {
* return false;
* }
*
* double cdx = pc.x - pdx;
* double cdy = pc.y - pdy;
*
* double cdxady = cdx * ady;
* double adxcdy = adx * cdy;
* double ocad = cdxady - adxcdy;
*
* if (ocad <= EPSILON) {
* return false;
* }
*
* return true;
* }
*
*/
bool InScanArea( Point& pa, Point& pb, Point& pc, Point& pd )
{
double oadb = (pa.x - pb.x) * (pd.y - pb.y) - (pd.x - pb.x) * (pa.y - pb.y);
if( oadb >= -EPSILON )
{
return false;
}
double oadc = (pa.x - pc.x) * (pd.y - pc.y) - (pd.x - pc.x) * (pa.y - pc.y);
if( oadc <= EPSILON )
{
return false;
}
return true;
}
}
#endif
|
