/* 
 * +-------------------+  Christian Schlittchen <corwin@amber.kn-bremen.de>
 * |                   |  Enno Rehling <enno@eressea.de>
 * | Eressea PBEM host |  Katja Zedel <katze@felidae.kn-bremen.de>
 * | (c) 1998 - 2005   |  
 * |                   |  This program may not be used, modified or distributed
 * +-------------------+  without prior permission by the authors of Eressea.
 *  
 */
#ifndef UTIL_RNG_H
#define UTIL_RNG_H
#ifdef __cplusplus
extern "C" {
#endif

#define RNG_MT

#ifdef RNG_MT
  /* initializes mt[N] with a seed */
  extern void init_genrand(unsigned long s);

  /* generates a random number on [0,0xffffffff]-interval */
  extern unsigned long genrand_int32(void);

  /* generates a random number on [0,1)-real-interval */
  extern double rng_injectable_double(void);

  /* generates a random number on [0,0x7fffffff]-interval */
  long genrand_int31(void);

# define rng_init(seed) init_genrand(seed)
# define rng_int (int)genrand_int31
# define rng_uint (unsigned int)genrand_int32
# define rng_double rng_injectable_double
# define RNG_RAND_MAX 0x7fffffff
#else
# include <stdlib.h>
# define rng_init(seed) srand(seed)
# define rng_int rand()
# define rng_double ((rand()%RAND_MAX)/(double)RAND_MAX)
# define RNG_RAND_MAX RAND_MAX
#endif
#define RAND_ROUND(fractional) ((rng_double() < fractional-(int)fractional)?((int)fractional+1):((int)fractional))
#ifdef __cplusplus
}
#endif
#endif