Random.h

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#ifndef MiscLib__RANDOM_HEADER__
#define MiscLib__RANDOM_HEADER__
/*
 * random.h -- Random number generation interface
 *
 *  for further details see Knuth TAOCP Vol.2 pp. 186f
 *
 */
 
#define MiscLib_RN_BUFSIZE 500
#define MiscLib_RN_RAND_MOD (1L << 30)
#define MiscLib_RN_CONST 6180339887L
 
namespace MiscLib
{
    extern size_t rn_buf[];
    extern size_t rn_point;
    void rn_setseed(size_t);
    size_t rn_refresh(void);
 
    inline size_t
    rn_rand()
    {
        size_t idx = rn_point++;
        return (MiscLib_RN_BUFSIZE > idx) ? rn_buf[idx] : rn_refresh();
    }
 
    inline size_t
    rn_urand(size_t m)
    {
        return rn_rand() % m;
    }
 
    inline float
    rn_frand()
    {
        return (float)rn_rand() / MiscLib_RN_RAND_MOD;
    }
}; // namespace MiscLib
 
#endif