Line data    Source code

       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             : 
      31             : /**
      32             :  * A random number generator.
      33             :  *
      34             :  * Generates a set of random, or if not supported by the operating system,
      35             :  * pseudo-random numbers. Each instance creates its own series of numbers.
      36             :  * @deprecated Use Boost.Random
      37             :  *
      38             :  * Example: @include tests/rng.cpp
      39             :  */
      40             : class RNG : public boost::noncopyable
      41             : {
      42             : public:
      43             :     /** Construct a new random number generator. @version 1.0 */
      44             :     LUNCHBOX_API RNG();
      45             : 
      46             :     /** Destruct the random number generator. @version 1.0 */
      47             :     LUNCHBOX_API ~RNG();
      48             : 
      49             :     /** Re-initialize the seed value for pseudo RNG's. @version 1.0 */
      50             :     LUNCHBOX_API void reseed();
      51             : 
      52             :     /**
      53             :      * Generate a random number.
      54             :      *
      55             :      * The returned number is between min..max for integer types, and
      56             :      * between 0..1 for floating-point types.
      57             :      * @return a random number.
      58             :      * @version 1.0
      59             :      */
      60    11197977 :     template< typename T > T get()
      61             :         {
      62      100000 :             T value;
      63    11197977 :             if( !_get( &value, sizeof( T )))
      64          90 :                 return T();
      65    11200354 :             return value;
      66             :         }
      67             : 
      68             : private:
      69             :     detail::RNG* const _impl;
      70             : 
      71             :     static LUNCHBOX_API bool _init();
      72             :     static void _exit();
      73             :     friend LUNCHBOX_API bool init( const int argc, char** argv );
      74             :     LUNCHBOX_API bool _get( void* data, size_t size );
      75             : }; // LB_DEPRECATED;
      76             : 
      77          30 : template<> inline float RNG::get()
      78             : {
      79             :     const float max_limits =
      80          30 :         static_cast< float >( std::numeric_limits< uint32_t >::max( ));
      81          30 :     return ((float)get< uint32_t >() / max_limits);
      82             : }
      83             : 
      84          16 : template<> inline double RNG::get()
      85             : {
      86             :     const double max_limits =
      87          16 :         static_cast< double >( std::numeric_limits< uint64_t >::max( ));
      88          16 :     return ((double)get< uint64_t >() / max_limits);
      89             : }
      90             : 
      91             : template<> inline bool RNG::get()
      92             : {
      93             :     return ( get< uint32_t >() & 1 );
      94             : }
      95             : }
      96             : #endif  // LUNCHBOX_RNG_H