/*
* Copyright (C) 2008 Michael Niedermayer
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* This code implements the KISS99 PRNG algorithm from George Marsaglia
*/
typedef struct KISSState{
uint32_t z,w,jsr,jcong;
}KISSState;
static uint32_t get_random(KISSState *s){
s->z = (s->z>>16) + 36969*(s->z&0xFFFF);
s->w = (s->w>>16) + 18000*(s->w&0xFFFF);
s->jsr ^= s->jsr<<17;
s->jsr ^= s->jsr>>13;
s->jsr ^= s->jsr<< 5;
s->jcong= 1234567 + 69069*s->jcong;
return ((s->w + (s->z<<16)) ^ s->jcong) + s->jsr;
}
static void init_random(KISSState *s, uint32_t seed){
s->z = 362436069 ^ seed;
s->w = 521288629 ^ (987654321*seed);
s->jsr = 123456789 + seed;
s->jcong= 380116160 - 314159265*seed;
}