ddcRandom.h

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//-*- Mode: C++ -*-
//  DDC originally by Alexey Sokirko
//  Changes and modifications 2011-2015 by Bryan Jurish
//
//  This file is part of DDC.
// 
//  DDC is free software: 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, either version 3 of the License, or
//  (at your option) any later version.
// 
//  DDC 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 DDC.  If not, see <http://www.gnu.org/licenses/>.
//

#ifndef DDC_RANDOM_H
#define DDC_RANDOM_H

#include <stdlib.h>
#include "ddcConfig.h"

#if defined(HAVE_ERAND48) || defined(HAVE_JRAND48) || defined(HAVE_NRAND48)
# define DDC_RAND48 1
#else
# undef DDC_RAND48
#endif

//======================================================================
class DDCRandom {
public:
    unsigned int m_seed;

#ifdef DDC_RAND48
    unsigned short m_state[3];
#endif

public:
    //------------------------------------------------------------

    DDCRandom(unsigned int seed=0)
    {
        set_seed(seed);
    };

    void set_seed(unsigned int seed=0)
    {
        m_seed = seed;
#ifdef DDC_RAND48
        m_state[0]=seed;
        m_state[1]=seed;
        m_state[2]=seed;
#endif
    };

    ~DDCRandom(void) {};

public:
    //------------------------------------------------------------


    inline double random_d(void) {
#if defined(HAVE_ERAND48)
        return erand48(m_state);
#elif defined(HAVE_RAND_R)
        return (double)rand_r(&m_seed) / (double)RAND_MAX;
#else
        srand(m_seed++);
        return (double)rand() / (double)RAND_MAX;
#endif
    };

    inline long random_l(void) {
#if defined(HAVE_JRAND48)
        return (long)jrand48(m_state);
#elif defined(HAVE_RAND_R)
        return (long)rand_r(&m_seed);
#else
        srand(m_seed++);
        return (long)rand();
#endif
    };

    inline long random_n(void) {
        //return (unsigned long)random_l();
#if defined(HAVE_NRAND48)
        return (long)nrand48(m_state);
#else
        return random_l();
#endif
    };
};

#endif /* DDC_RANDOM_H */

/*--- emacs style variables ---
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 * End:
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