/*
 * fast pseudo random generation 
 *
 * $Id$
 *
 * Copyright (C) 2007 iptelorg GmbH
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
/*
 *History:
 *--------
 *  2007-06-15  wrapper around isaac (see 
 *              http://www.burtleburtle.net/bob/rand/isaacafa.html) (andrei)
 */

#include "fastrand.h"

#include <stdlib.h>
#include "isaac/rand.h"

#define FASTRAND_MAX  ((unsigned int)(-1))

static randctx is_ctx;


/* side effect: seeds also random w/ seed */
void fastrand_seed(unsigned int seed)
{
	int i;
	
	srandom(seed);
	for (i=0; i<RANDSIZ; i++)
		is_ctx.randrsl[i]=random();
	randinit(&is_ctx, 1);
}


unsigned int fastrand()
{
	return rand(&is_ctx);
}

/* generate a random number between 0 and max ( 0 <=r<=max) */
unsigned int fastrand_max(unsigned int max)
{
	return fastrand()%(max+1);
}