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
	RNG ()
	Construct a new random number generator. More...
	~RNG ()
	Destruct the random number generator. More...
template<typename T >
T	get ()
	Generate a random number. More...
template<>
float	get ()
template<>
double	get ()
template<>
bool	get ()

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 <lunchbox/test.h>

#include <lunchbox/clock.h>
#include <lunchbox/init.h>
#include <lunchbox/rng.h>
#include <servus/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 " << std::to_string(min)  \
                                                 << " for " << #type);   \
        i = MAXLOOPS;                                                    \
        while (--i)                                                      \
            if (rng.get<type>() >= (max))                                \
                break;                                                   \
        TESTINFO(i, "Did never get value above " << std::to_string(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<servus::uint128_t>();

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

Definition at line 43 of file rng.h.

Constructor & Destructor Documentation

lunchbox::RNG::RNG

(

)

Construct a new random number generator.

Version

1.0

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 61 of file rng.h.

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

• rng.h