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rng.h
1 
2 /* Copyright (c) 2007-2014, Stefan Eilemann <eile@equalizergraphics.com>
3  *
4  * This library is free software; you can redistribute it and/or modify it under
5  * the terms of the GNU Lesser General Public License version 2.1 as published
6  * by the Free Software Foundation.
7  *
8  * This library is distributed in the hope that it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
10  * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
11  * details.
12  *
13  * You should have received a copy of the GNU Lesser General Public License
14  * along with this library; if not, write to the Free Software Foundation, Inc.,
15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16  */
17 
18 #ifndef LUNCHBOX_RNG_H
19 #define LUNCHBOX_RNG_H
20 
21 #include <lunchbox/debug.h> // for LBASSERT
22 #include <lunchbox/init.h> // friend function
23 #include <lunchbox/types.h>
24 #include <boost/noncopyable.hpp>
25 #include <limits>
26 
27 namespace lunchbox
28 {
29 namespace detail { class RNG; }
30 
40 class RNG : public boost::noncopyable
41 {
42 public:
44  LUNCHBOX_API RNG();
45 
47  LUNCHBOX_API ~RNG();
48 
57  template< typename T > T get()
58  {
59  T value;
60  if( !_get( &value, sizeof( T )))
61  return T();
62  return value;
63  }
64 
65 private:
66  LUNCHBOX_API bool _get( void* data, size_t size );
67 }; // LB_DEPRECATED;
68 
69 template<> inline float RNG::get()
70 {
71  const float max_limits =
72  static_cast< float >( std::numeric_limits< uint32_t >::max( ));
73  return ((float)get< uint32_t >() / max_limits);
74 }
75 
76 template<> inline double RNG::get()
77 {
78  const double max_limits =
79  static_cast< double >( std::numeric_limits< uint64_t >::max( ));
80  return ((double)get< uint64_t >() / max_limits);
81 }
82 
83 template<> inline bool RNG::get()
84 {
85  return ( get< uint32_t >() & 1 );
86 }
87 }
88 #endif // LUNCHBOX_RNG_H
Basic type definitions not provided by the operating system.
A random number generator.
Definition: rng.h:40
LUNCHBOX_API RNG()
Construct a new random number generator.
LUNCHBOX_API ~RNG()
Destruct the random number generator.
T get()
Generate a random number.
Definition: rng.h:57