/*
*
* gPlanarity:
* The geeky little puzzle game with a big noodly crunch!
*
* gPlanarity copyright (C) 2005 Monty
* Original Flash game by John Tantalo
* Original game concept by Mary Radcliffe
*
* gPlanarity 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, or (at your option)
* any later version.
*
* gPlanarity 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 Postfish; see the file COPYING. If not, write to the
* Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*
*/
#include "random.h"
// Portable 32 bit random number generator. It's not crypto-grade,
// but we don't need crypto-grade. We need complete control over the
// result sequence and reproducability, so we can't use any local
// generator. As long as it's 100% consistent across
// platforms/OSes/compilers and fairly uniform (doesn't always return
// 17), we're all set.
// This is a C derivative of the PASCAL "Integer Version 2" minimal
// standard number generator thich appears in the article:
// Park, Steven K. and Miller, Keith W., "Random Number
// Generators: Good Ones are Hard to Find", Communications of the
// ACM, October, 1988.
static int32_t next = 123456789;
void random_seed(int32_t seed){
next = seed;
}
#define MPLIER 16807
#define MOBYMP 127773
#define MOMDMP 2836
int32_t random_number(){
int32_t hival, loval, testval;
hival = next / MOBYMP;
loval = next % MOBYMP;
testval = MPLIER*loval - MOMDMP*hival;
if (testval > 0)
next = testval;
else
next = testval + MAX_G_RAND;
return next;
}
int random_yes(int per128_yes){
u_int32_t num = (u_int32_t)random_number();
return (num < (unsigned int)per128_yes << 24U);
}