1
0
Fork 0
flightgear/Time/fg_timer.c

180 lines
5 KiB
C

/**************************************************************************
* fg_timer.c -- time handling routines
*
* Written by Curtis Olson, started June 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)
**************************************************************************/
#include <signal.h> /* for timer routines */
#include <stdio.h> /* for printf() */
#ifdef USE_FTIME
# include <sys/timeb.h> /* for ftime() and struct timeb */
#elif defined(__MWERKS__)
# include <windows.h> /* For Metrowerks environment */
# include <winbase.h> /* There is no ANSI/MSL time function that */
/* contains milliseconds */
#else
# include <sys/time.h> /* for get/setitimer, gettimeofday, struct timeval */
#endif /* USE_FTIME */
#include <Time/fg_timer.h>
unsigned long int fgSimTime;
#ifdef USE_ITIMER
static struct itimerval t, ot;
static void (*callbackfunc)(int multi_loop);
/* This routine catches the SIGALRM */
void fgTimerCatch( void ) {
/* ignore any SIGALRM's until we come back from our EOM iteration */
signal(SIGALRM, SIG_IGN);
/* printf("In fgTimerCatch()\n"); */
/* -1 tells the routine to use default interval rather than something
dynamically calculated based on frame rate */
callbackfunc(-1);
signal(SIGALRM, fgTimerCatch);
}
/* this routine initializes the interval timer to generate a SIGALRM after
* the specified interval (dt) */
void fgTimerInit(float dt, void (*f)()) {
int terr;
int isec;
float usec;
callbackfunc = f;
isec = (int) dt;
usec = 1000000* (dt - (float) isec);
t.it_interval.tv_sec = isec;
t.it_interval.tv_usec = usec;
t.it_value.tv_sec = isec;
t.it_value.tv_usec = usec;
/* printf("fgTimerInit() called\n"); */
fgTimerCatch(); /* set up for SIGALRM signal catch */
terr = setitimer( ITIMER_REAL, &t, &ot );
if (terr) {
printf("Error returned from setitimer");
exit(0);
}
}
#endif /* HAVE_ITIMER */
/* This function returns the number of milleseconds since the last
time it was called. */
int fgGetTimeInterval( void ) {
int interval;
static int inited = 0;
#ifdef USE_FTIME
static struct timeb last;
static struct timeb current;
#elif defined (__MWERKS__)
SYSTEMTIME last;
SYSTEMTIME current;
#else
static struct timeval last;
static struct timeval current;
static struct timezone tz;
#endif /* USE_FTIME */
if ( ! inited ) {
inited = 1;
#ifdef USE_FTIME
ftime(&last);
#elif defined (__MWERKS__)
GetLocalTime(&last);
#else
gettimeofday(&last, &tz);
#endif /* USE_FTIME */
interval = 0;
} else {
#ifdef USE_FTIME
ftime(&current);
interval = 1000 * (current.time - last.time) +
(current.millitm - last.millitm);
#elif defined (__MWERKS__)
GetLocalTime(&current);
interval = 1000 * (current.wSecond - last.wSecond) +
(current.wMilliseconds - last.wMilliseconds);
#else
gettimeofday(&current, &tz);
interval = 1000000 * (current.tv_sec - last.tv_sec) +
(current.tv_usec - last.tv_usec);
interval /= 1000; /* convert back to milleseconds */
#endif /* USE_FTIME */
last = current;
}
return(interval);
}
/* $Log$
/* Revision 1.10 1998/01/31 00:43:45 curt
/* Added MetroWorks patches from Carmen Volpe.
/*
* Revision 1.9 1998/01/19 19:27:21 curt
* Merged in make system changes from Bob Kuehne <rpk@sgi.com>
* This should simplify things tremendously.
*
* Revision 1.8 1998/01/19 18:40:39 curt
* Tons of little changes to clean up the code and to remove fatal errors
* when building with the c++ compiler.
*
* Revision 1.7 1997/12/30 13:06:58 curt
* A couple lighting tweaks ...
*
* Revision 1.6 1997/07/12 02:13:04 curt
* Add ftime() support for those that don't have gettimeofday()
*
* Revision 1.5 1997/06/26 19:08:38 curt
* Restructuring make, adding automatic "make dep" support.
*
* Revision 1.4 1997/06/25 15:39:49 curt
* Minor changes to compile with rsxnt/win32.
*
* Revision 1.3 1997/06/17 16:52:04 curt
* Timer interval stuff now uses gettimeofday() instead of ftime()
*
* Revision 1.2 1997/06/17 03:41:10 curt
* Nonsignal based interval timing is now working.
* This would be a good time to look at cleaning up the code structure a bit.
*
* Revision 1.1 1997/06/16 19:24:20 curt
* Initial revision.
*
*/