/*
 * Copyright (C) 2013 Freie Universität Berlin
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */


/**
 * @defgroup    sys_random Random
 * @ingroup     sys
 * @brief       Random number generator
 * @{
 *
 * @file
 * @brief       Mersenne Twister - a very fast random number generator
 */

#ifndef RANDOM_H
#define RANDOM_H

#include <inttypes.h>

#ifdef __cplusplus
extern "C" {
#endif

#ifndef PRNG_FLOAT
#  define PRNG_FLOAT (0)
#endif

/**
 * @brief initializes mt[N] with a seed
 *
 * @param s seed for the PRNG
 */
void genrand_init(uint32_t s);

/**
 * @brief initialize by an array with array-length
 * init_key is the array for initializing keys
 * key_length is its length
 * slight change for C++, 2004/2/26
 *
 * @param init_key array of keys (seeds) to initialize the PRNG
 * @param key_length number of lements in init_key
 */
void genrand_init_by_array(uint32_t init_key[], int key_length);

/**
 * @brief generates a random number on [0,0xffffffff]-interval
 * @return a random number on [0,0xffffffff]-interval
 */
uint32_t genrand_uint32(void);


#if PRNG_FLOAT
/* These real versions are due to Isaku Wada, 2002/01/09 added */

/**
 * @brief generates a random number on [0,1)-real-interval
 * @return a random number on [0,1)-real-interval
 */
double genrand_real(void);

/**
 * @brief generates a random number on [0,1]-real-interval
 * @return a random number on [0,1]-real-interval
 */
double genrand_real_inclusive(void);

/**
 * @brief generates a random number on (0,1)-real-interval
 * @return a random number on (0,1)-real-interval
 */
double genrand_real_exclusive(void);

/**
 * @brief generates a random number on [0,1) with 53-bit resolution
 * @return a random number on [0,1) with 53-bit resolution
 */
double genrand_res53(void);

#endif /* PRNG_FLOAT */

#ifdef __cplusplus
}
#endif

#endif /* RANDOM_H */
/** @} */