lunchbox::RNG Class Reference

A random number generator. More...

#include <rng.h>

Inheritance diagram for lunchbox::RNG:

Collaboration diagram for lunchbox::RNG:

Public Member Functions
LUNCHBOX_API	RNG ()
	Construct a new random number generator. More...
LUNCHBOX_API	~RNG ()
	Destruct the random number generator. More...
LUNCHBOX_API void	reseed ()
	Re-initialize the seed value for pseudo RNG's. More...
template<typename T >
T	get ()
	Generate a random number. More...
template<>
float	get ()
template<>
double	get ()
template<>
bool	get ()

Friends
LUNCHBOX_API bool	init (const int argc, char **argv)
	Initialize the Lunchbox base classes. More...

Detailed Description

A random number generator.

Generates a set of random, or if not supported by the operating system, pseudo-random numbers. Each instance creates its own series of numbers.

Deprecated:

Use Boost.Random

Example:

/* Copyright (c) 2007-2012, Stefan Eilemann <eile@equalizergraphics.com> 
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 2.1 as published
 * by the Free Software Foundation.
 *  
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

// Tests the functionality of the random number generator

#include <test.h>

#include <lunchbox/clock.h>
#include <lunchbox/init.h>
#include <lunchbox/rng.h>
#include <lunchbox/uint128_t.h>

#define MAXLOOPS 100000

#define TESTLOOP( type, min, max )                                      \
{                                                                       \
    size_t i = MAXLOOPS;                                                \
    while( --i )                                                        \
        if( rng.get< type >() <= ( min ))                               \
            break;                                                      \
    TESTINFO( i, "Did never get value below " << (min) << " for " << #type ); \
    i = MAXLOOPS;                                                       \
    while( --i )                                                        \
        if( rng.get< type >() >= ( max ))                               \
            break;                                                      \
    TESTINFO( i, "Did never get value above " << (max) << " for " << #type ); \
    {                                                                   \
        const type value = rng.get< type >();                           \
        i = MAXLOOPS;                                                   \
        while( --i )                                                    \
            if( rng.get< type >() != value )                            \
                break;                                                  \
        TESTINFO( i, "Always get the same value " << value << " for "   \
                  << #type );                                           \
    }                                                                   \
}

template< class T > void testSpeed()
{
    lunchbox::RNG rng;
    lunchbox::Clock clock;
    for( size_t i = 0; i < MAXLOOPS; ++i )
        rng.get< T >();
    std::cout << float( MAXLOOPS ) * sizeof( T ) / clock.getTimef()
              << " byte/ms in " << sizeof( T ) << " byte reads" << std::endl;
}

int main( int argc, char **argv )
{
    TEST( lunchbox::init( argc, argv ));

    lunchbox::RNG rng;

    TESTLOOP( uint8_t,  0,        255 );
    TESTLOOP( uint16_t, 50,       65000 );
    TESTLOOP( uint32_t, 1<<20,    1u<<12 );
    TESTLOOP( uint64_t, 1ull<<52, 1ull<<12 );

    TESTLOOP( int8_t,  -126,       127 );
    TESTLOOP( int16_t, -32000,     32000 );
    TESTLOOP( int32_t, -1<<5,      1<<5 );
    TESTLOOP( int64_t, -1<<10,     1<<10 );

    TESTLOOP( float,  0.1f, 0.9f );
    TESTLOOP( double, 0.1,  0.9 );

    testSpeed< uint8_t >();
    testSpeed< uint16_t >();
    testSpeed< uint32_t >();
    testSpeed< uint64_t >();
    testSpeed< lunchbox::uint128_t >();

    TEST( lunchbox::exit( ));
    return EXIT_SUCCESS;
}

Definition at line 40 of file rng.h.

Constructor & Destructor Documentation

LUNCHBOX_API lunchbox::RNG::RNG

(

)

Construct a new random number generator.

Version

1.0

LUNCHBOX_API lunchbox::RNG::~RNG

(

)

Destruct the random number generator.

Version

1.0

Member Function Documentation

template<typename T >

T lunchbox::RNG::get ( )

inline

Generate a random number.

The returned number is between min..max for integer types, and between 0..1 for floating-point types.

Returns

a random number.

Version

1.0

Definition at line 60 of file rng.h.

LUNCHBOX_API void lunchbox::RNG::reseed

(

)

Re-initialize the seed value for pseudo RNG's.

Version

1.0

Friends And Related Function Documentation

LUNCHBOX_API bool init ( const int  argc, char **  argv  )

friend

Initialize the Lunchbox base classes.

exit() should be called independent of the return value of this function.

Parameters

argc	the command line argument count.
argv	the command line argument values.

Returns

true if the library was successfully initialised, false otherwise

Version

1.0

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The documentation for this class was generated from the following file:

• rng.h