1 // sg_random.c -- routines to handle random number generation
3 // Written by Curtis Olson, started July 1997.
5 // Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
7 // This library is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU Library General Public
9 // License as published by the Free Software Foundation; either
10 // version 2 of the License, or (at your option) any later version.
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // Library General Public License for more details.
17 // You should have received a copy of the GNU Library General Public
18 // License along with this library; if not, write to the
19 // Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 // Boston, MA 02111-1307, USA.
26 #include <stdlib.h> // for random(), srandom()
27 #include <time.h> // for time() to seed srandom()
29 #include "sg_random.h"
34 # define RAND_MAX 2147483647
41 void srandom(unsigned int seed);
46 // Seed the random number generater with time() so we don't see the
47 // same sequence every time
48 void sg_srandom_time() {
57 // Seed the random number generater with your own seed so can set up
58 // repeatable randomization.
59 void sg_srandom( unsigned int seed ) {
68 // return a random number between [0.0, 1.0)
71 return(rand() / (double)RAND_MAX);
73 return(random() / (double)RAND_MAX);