simgear/Math/fg_random.c

110 lines
3.1 KiB
C

/**************************************************************************
* fg_random.c -- routines to handle random number generation
*
* Written by Curtis Olson, started July 1997.
*
* Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
* (Log is kept at end of this file)
**************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h> /* for random(), srandom() */
#include <time.h> /* for time() to seed srandom() */
#include <Debug/fg_debug.h>
#include "fg_random.h"
#ifndef HAVE_RAND
# ifdef sgi
# undef RAND_MAX
# define RAND_MAX 2147483647
# endif
#endif
#ifdef __SUNPRO_CC
extern "C" {
long int random(void);
void srandom(unsigned int seed);
}
#endif
/* Seed the random number generater with time() so we don't see the
* same sequence every time */
void fg_srandom(void) {
fgPrintf( FG_MATH, FG_INFO, "Seeding random number generater\n");
#ifdef HAVE_RAND
srand(time(NULL));
#else
srandom(time(NULL));
#endif
}
/* return a random number between [0.0, 1.0) */
double fg_random(void) {
#ifdef HAVE_RAND
return(rand() / (double)RAND_MAX);
#else
return(random() / (double)RAND_MAX);
#endif
}
/* $Log$
/* Revision 1.8 1998/04/25 22:06:23 curt
/* Edited cvs log messages in source files ... bad bad bad!
/*
* Revision 1.7 1998/04/24 00:43:13 curt
* Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
*
* Revision 1.6 1998/04/18 03:53:42 curt
* Miscellaneous Tweaks.
*
* Revision 1.5 1998/04/03 22:10:29 curt
* Converting to Gnu autoconf system.
*
* Revision 1.4 1998/02/03 23:20:28 curt
* Lots of little tweaks to fix various consistency problems discovered by
* Solaris' CC. Fixed a bug in fg_debug.c with how the fgPrintf() wrapper
* passed arguments along to the real printf(). Also incorporated HUD changes
* by Michele America.
*
* Revision 1.3 1998/01/27 00:47:59 curt
* Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
* system and commandline/config file processing code.
*
* Revision 1.2 1997/12/30 20:47:48 curt
* Integrated new event manager with subsystem initializations.
*
* Revision 1.1 1997/07/30 16:04:09 curt
* Moved random routines from Utils/ to Math/
*
* Revision 1.1 1997/07/19 22:31:57 curt
* Initial revision.
*
*/