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/* Copyright (c) 1997-2003 Miller Puckette, krzYszcz, and others.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution. */
#include <time.h>
#include "m_pd.h"
EXTERN double sys_getrealtime(void); /* used to be in m_imp.h */
#include "common/rand.h"
/* borrowed from x_misc.c, LATER rethink */
void rand_seed(unsigned int *statep, unsigned int seed)
{
if (seed) *statep = (seed & 0x7fffffff);
else
{
/* LATER consider using time elapsed from system startup,
(or login -- in linux we might call getutent) */
static unsigned int failsafe = 1489853723;
static int shift = 0;
static unsigned int lastticks = 0;
/* LATER rethink -- it might fail on faster machine than mine
(but does it matter?) */
unsigned int newticks = (unsigned int)(sys_getrealtime() * 1000000.);
if (newticks == lastticks)
{
failsafe = failsafe * 435898247 + 938284287;
*statep = (failsafe & 0x7fffffff);
#ifdef RAND_DEBUG
post("rand_seed failed (newticks %d)", newticks);
#endif
}
else
{
if (!shift)
shift = (int)time(0); /* LATER deal with error return (-1) */
*statep = ((newticks + shift) & 0x7fffffff);
#if 0
post("rand_seed: newticks %d, shift %d", newticks, shift);
#endif
}
lastticks = newticks;
}
}
/* borrowed from x_misc.c, LATER rethink */
int rand_int(unsigned int *statep, int range)
{
int result;
*statep = *statep * 472940017 + 832416023;
result = ((double)range) * ((double)*statep) * (1./4294967296.);
return (result < range ? result : range - 1);
}
/* borrowed from d_osc.c, LATER rethink */
float rand_float(unsigned int *statep)
{
float result = ((float)((*statep & 0x7fffffff) - 0x40000000))
* (float)(1.0 / 0x40000000);
*statep = *statep * 435898247 + 382842987;
return (result);
}
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