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flightgear/Simulator/Time/fg_timer.cxx
1999-04-05 21:32:32 +00:00

193 lines
5.4 KiB
C++

// fg_timer.cxx -- 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)
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <signal.h> // for timer routines
#include <stdio.h> // for printf()
#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#endif
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h> // for get/setitimer, gettimeofday, struct timeval
#endif
#include "fg_time.hxx"
#include "fg_timer.hxx"
#include "timestamp.hxx"
unsigned long int fgSimTime;
#ifdef HAVE_SETITIMER
static struct itimerval t, ot;
static void (*callbackfunc)(int multi_loop);
// This routine catches the SIGALRM
void fgTimerCatch( int dummy ) {
int warning_avoider;
// get past a compiler warning
warning_avoider = dummy;
// 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 )) {
int terr;
int isec;
int usec;
callbackfunc = f;
isec = (int) dt;
usec = 1000000 * ((int)dt - 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(0); // set up for SIGALRM signal catch
terr = setitimer( ITIMER_REAL, &t, &ot );
if (terr) {
printf("Error returned from setitimer");
exit(0);
}
}
#endif // HAVE_SETITIMER
// This function returns the number of microseconds since the last
// time it was called.
int fgGetTimeInterval( void ) {
int interval;
static int inited = 0;
static FGTimeStamp last;
FGTimeStamp current;
if ( ! inited ) {
inited = 1;
last.stamp();
interval = 0;
} else {
current.stamp();
interval = current - last;
last = current;
}
return(interval);
}
// $Log$
// Revision 1.1 1999/04/05 21:32:47 curt
// Initial revision
//
// Revision 1.6 1999/01/09 13:37:45 curt
// Convert fgTIMESTAMP to FGTimeStamp which holds usec instead of ms.
//
// Revision 1.5 1998/12/05 14:21:32 curt
// Moved struct fg_timestamp to class fgTIMESTAMP and moved it's definition
// to it's own file, timestamp.hxx.
//
// Revision 1.4 1998/12/04 01:32:51 curt
// Converted "struct fg_timestamp" to "class fgTIMESTAMP" and added some
// convenience inline operators.
//
// Revision 1.3 1998/04/28 01:22:18 curt
// Type-ified fgTIME and fgVIEW.
//
// Revision 1.2 1998/04/25 20:24:03 curt
// Cleaned up initialization sequence to eliminate interdependencies
// between sun position, lighting, and view position. This creates a
// valid single pass initialization path.
//
// Revision 1.1 1998/04/24 00:52:29 curt
// Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
// Fog color fixes.
// Separated out lighting calcs into their own file.
//
// Revision 1.12 1998/04/21 17:01:44 curt
// Fixed a problems where a pointer to a function was being passed around. In
// one place this functions arguments were defined as ( void ) while in another
// place they were defined as ( int ). The correct answer was ( int ).
//
// Prepairing for C++ integration.
//
// Revision 1.11 1998/04/03 22:12:56 curt
// Converting to Gnu autoconf system.
// Centralized time handling differences.
//
// 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.
//