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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
// Copyright (c) 2000 Utrecht University (The Netherlands),
// ETH Zurich (Switzerland), Freie Universitaet Berlin (Germany),
// INRIA Sophia-Antipolis (France), Martin-Luther-University Halle-Wittenberg
// (Germany), Max-Planck-Institute Saarbruecken (Germany), RISC Linz (Austria),
// and Tel-Aviv University (Israel). All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; version 2.1 of the License.
// See the file LICENSE.LGPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/branches/CGAL-3.2-branch/Intersections_2/include/CGAL/Triangle_2_Triangle_2_do_intersect.h $
// $Id: Triangle_2_Triangle_2_do_intersect.h 28567 2006-02-16 14:30:13Z lsaboret $
//
//
// Author(s) : Philippe Guigue
#ifndef CGAL_TRIANGLE_2_TRIANGLE_2_DO_INTERSECT_H
#define CGAL_TRIANGLE_2_TRIANGLE_2_DO_INTERSECT_H
#include <CGAL/Triangle_2.h>
CGAL_BEGIN_NAMESPACE
namespace CGALi {
template <class K>
bool intersection_test_vertex(const typename K::Point_2 * P1,
const typename K::Point_2 * Q1,
const typename K::Point_2 * R1,
const typename K::Point_2 * P2,
const typename K::Point_2 * Q2,
const typename K::Point_2 * R2,
const K & k ){
CGAL_kernel_precondition( k.orientation_2_object() (*P1,*Q1,*R1)
== POSITIVE);
CGAL_kernel_precondition( k.orientation_2_object() (*P2,*Q2,*R2)
== POSITIVE);
typename K::Orientation_2 orientation =
k.orientation_2_object();
if (orientation(*R2,*P2,*Q1) != NEGATIVE) {
if (orientation(*R2,*Q2,*Q1) != POSITIVE) {
if (orientation(*P1,*P2,*Q1) == POSITIVE)
return orientation(*P1,*Q2,*Q1) != POSITIVE;
return orientation(*P1,*P2,*R1) != NEGATIVE
&& orientation(*Q1,*R1,*P2) != NEGATIVE ;
}
return orientation(*P1,*Q2,*Q1) != POSITIVE
&& orientation(*R2,*Q2,*R1) != POSITIVE
&& orientation(*Q1,*R1,*Q2) != NEGATIVE ;
}
if (orientation(*R2,*P2,*R1) != NEGATIVE) {
if (orientation(*Q1,*R1,*R2) != NEGATIVE)
return orientation(*P1,*P2,*R1) != NEGATIVE;
return orientation(*Q1,*R1,*Q2) != NEGATIVE
&& orientation(*R2,*R1,*Q2) != NEGATIVE;
}
return false;
}
template <class K>
bool intersection_test_edge(const typename K::Point_2 * P1,
const typename K::Point_2 * Q1,
const typename K::Point_2 * R1,
const typename K::Point_2 * P2,
const typename K::Point_2 * Q2,
const typename K::Point_2 * R2,
const K & k ){
CGAL_kernel_precondition( k.orientation_2_object() (*P1,*Q1,*R1)
== POSITIVE);
CGAL_kernel_precondition( k.orientation_2_object() (*P2,*Q2,*R2)
== POSITIVE);
typename K::Orientation_2 orientation =
k.orientation_2_object();
if (orientation(*R2,*P2,*Q1) != NEGATIVE) {
if (orientation(*P1,*P2,*Q1) != NEGATIVE)
return orientation(*P1,*Q1,*R2) != NEGATIVE;
return orientation(*Q1,*R1,*P2) != NEGATIVE
&& orientation(*R1,*P1,*P2) != NEGATIVE;
}
if (orientation(*R2,*P2,*R1) != NEGATIVE)
return orientation(*P1,*P2,*R1) != NEGATIVE
&& ( orientation(*P1,*R1,*R2) != NEGATIVE
|| orientation(*Q1,*R1,*R2) != NEGATIVE ) ;
return false;
}
template <class K>
bool do_intersect(const typename CGAL_WRAP(K)::Triangle_2 &t1,
const typename CGAL_WRAP(K)::Triangle_2 &t2,
const K & k ){
CGAL_kernel_precondition( ! k.is_degenerate_2_object() (t1) );
CGAL_kernel_precondition( ! k.is_degenerate_2_object() (t2) );
typename K::Construct_vertex_2 vertex_on =
k.construct_vertex_2_object();
typename K::Orientation_2 orientation =
k.orientation_2_object();
typedef typename K::Point_2 Point_2;
const Point_2 & P1 = vertex_on(t1,0);
const Point_2 & Q1 = vertex_on(t1,1);
const Point_2 & R1 = vertex_on(t1,2);
const Point_2 & P2 = vertex_on(t2,0);
const Point_2 & Q2 = vertex_on(t2,1);
const Point_2 & R2 = vertex_on(t2,2);
const Point_2 * p1 = &P1;
const Point_2 * q1 = &Q1;
const Point_2 * r1 = &R1;
const Point_2 * p2 = &P2;
const Point_2 * q2 = &Q2;
const Point_2 * r2 = &R2;
if ( orientation(P1,Q1,R1) != POSITIVE ) {
q1 = &R1;;
r1 = &Q1;
}
if ( orientation(P2,Q2,R2) != POSITIVE ) {
q2 = &R2;
r2 = &Q2;
}
if ( orientation(*p2,*q2,*p1) != NEGATIVE ) {
if ( orientation(*q2,*r2,*p1) != NEGATIVE ) {
if ( orientation(*r2,*p2,*p1) != NEGATIVE ) return true;
return CGALi::intersection_test_edge(p1,q1,r1,p2,q2,r2,k);
}
if ( orientation(*r2,*p2,*p1) != NEGATIVE )
return CGALi::intersection_test_edge(p1,q1,r1,r2,p2,q2,k);
return CGALi::intersection_test_vertex(p1,q1,r1,p2,q2,r2,k);
}
if ( orientation(*q2,*r2,*p1) != NEGATIVE ) {
if ( orientation(*r2,*p2,*p1) != NEGATIVE )
return CGALi::intersection_test_edge(p1,q1,r1,q2,r2,p2,k);
return CGALi::intersection_test_vertex(p1,q1,r1,q2,r2,p2,k);
}
return CGALi::intersection_test_vertex(p1,q1,r1,r2,p2,q2,k);
}
} // namespace CGALi
template <class K>
inline bool do_intersect(const Triangle_2<K> &t1,
const Triangle_2<K> &t2)
{
typedef typename K::Do_intersect_2 Do_intersect;
return Do_intersect()(t1,t2);
}
CGAL_END_NAMESPACE
#endif //CGAL_TRIANGLE_2_TRIANGLE_2_DO_INTERSECT_H
|
