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
195
196
197
198
199
200
|
// Copyright (c) 1997 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-3.5-branch/Generator/include/CGAL/point_generators_3.h $
// $Id: point_generators_3.h 39778 2007-08-08 15:59:25Z spion $
//
//
// Author(s) : Lutz Kettner <kettner@inf.ethz.ch>
#ifndef CGAL_POINT_GENERATORS_3_H
#define CGAL_POINT_GENERATORS_3_H 1
#include <CGAL/generators.h>
#include <CGAL/point_generators_2.h>
#include <CGAL/number_type_basic.h>
CGAL_BEGIN_NAMESPACE
template < class P, class Creator =
Creator_uniform_3<typename Kernel_traits<P>::Kernel::RT,P> >
class Random_points_in_sphere_3 : public Random_generator_base<P> {
void generate_point();
public:
typedef Random_points_in_sphere_3<P,Creator> This;
Random_points_in_sphere_3( double r = 1, Random& rnd = default_random)
// g is an input iterator creating points of type `P' uniformly
// distributed in the open sphere with radius r, i.e. |`*g'| < r .
// Three random numbers are needed from `rnd' for each point.
: Random_generator_base<P>( r, rnd) { generate_point(); }
This& operator++() {
generate_point();
return *this;
}
This operator++(int) {
This tmp = *this;
++(*this);
return tmp;
}
};
template < class P, class Creator >
void
Random_points_in_sphere_3<P,Creator>::
generate_point() {
typedef typename Creator::argument_type T;
do {
Creator creator;
this->d_item =
creator( T(this->d_range * ( 2 * this->_rnd.get_double() - 1.0)),
T(this->d_range * ( 2 * this->_rnd.get_double() - 1.0)),
T(this->d_range * ( 2 * this->_rnd.get_double() - 1.0)));
}
while (CGAL::to_double(this->d_item.x() * this->d_item.x() +
this->d_item.y() * this->d_item.y() +
this->d_item.z() * this->d_item.z()) >=
this->d_range * this->d_range);
}
template < class P, class Creator =
Creator_uniform_3<typename Kernel_traits<P>::Kernel::RT,P> >
class Random_points_on_sphere_3 : public Random_generator_base<P> {
void generate_point();
public:
typedef Random_points_on_sphere_3<P,Creator> This;
Random_points_on_sphere_3( double r = 1, Random& rnd = default_random)
// g is an input iterator creating points of type `P' uniformly
// distributed on the circle with radius r, i.e. |`*g'| == r . A
// single random number is needed from `rnd' for each point.
: Random_generator_base<P>( r, rnd) { generate_point(); }
This& operator++() {
generate_point();
return *this;
}
This operator++(int) {
This tmp = *this;
++(*this);
return tmp;
}
};
template < class P, class Creator >
void
Random_points_on_sphere_3<P,Creator>::
generate_point() {
typedef typename Creator::argument_type T;
double alpha = this->_rnd.get_double() * 2.0 * CGAL_PI;
double z = 2 * this->_rnd.get_double() - 1.0;
double r = std::sqrt( 1 - z * z);
Creator creator;
this->d_item = creator( T(this->d_range * r * std::cos(alpha)),
T(this->d_range * r * std::sin(alpha)),
T(this->d_range * z));
}
template < class P, class Creator =
Creator_uniform_3<typename Kernel_traits<P>::Kernel::RT,P> >
class Random_points_in_cube_3 : public Random_generator_base<P>{
void generate_point();
public:
typedef Random_points_in_cube_3<P,Creator> This;
Random_points_in_cube_3( double a = 1, Random& rnd = default_random)
: Random_generator_base<P>( a, rnd) { generate_point(); }
This& operator++() {
generate_point();
return *this;
}
This operator++(int) {
This tmp = *this;
++(*this);
return tmp;
}
};
template < class P, class Creator >
void
Random_points_in_cube_3<P,Creator>::
generate_point() {
typedef typename Creator::argument_type T;
Creator creator;
this->d_item =
creator( T(this->d_range * ( 2 * this->_rnd.get_double() - 1.0)),
T(this->d_range * ( 2 * this->_rnd.get_double() - 1.0)),
T(this->d_range * ( 2 * this->_rnd.get_double() - 1.0)));
}
template <class OutputIterator, class Creator>
OutputIterator
points_on_cube_grid_3( double a, std::size_t n,
OutputIterator o, Creator creator)
{
if (n == 0)
return o;
int m = int(std::ceil(
std::sqrt(std::sqrt(static_cast<double>(n)))));
while (m*m*m < int(n)) m++;
double base = -a; // Left and bottom boundary.
double step = 2*a/(m-1);
int j = 0;
int k = 0;
double px = base;
double py = base;
double pz = base;
*o++ = creator( px, py, pz);
for (std::size_t i = 1; i < n; i++) {
j++;
if ( j == m) {
k++;
if ( k == m) {
py = base;
px = base;
pz = pz + step;
k = 0;
}
else {
px = base;
py = py + step;
}
j = 0;
} else {
px = px + step;
}
*o++ = creator( px, py, pz);
}
return o;
}
template <class OutputIterator>
OutputIterator
points_on_cube_grid_3( double a, std::size_t n, OutputIterator o)
{
typedef std::iterator_traits<OutputIterator> ITraits;
typedef typename ITraits::value_type P;
return points_on_square_grid_3(a, n, o,
Creator_uniform_3<typename Kernel_traits<P>::Kernel::RT,P>());
}
CGAL_END_NAMESPACE
#endif // CGAL_POINT_GENERATORS_3_H //
// EOF //
|
