1 // fg_timer.cxx -- time handling routines
3 // Written by Curtis Olson, started June 1997.
5 // Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 // (Log is kept at end of this file)
29 #include <signal.h> // for timer routines
30 #include <stdio.h> // for printf()
36 #ifdef HAVE_SYS_TIME_H
37 # include <sys/time.h> // for get/setitimer, gettimeofday, struct timeval
40 #include "fg_time.hxx"
41 #include "fg_timer.hxx"
42 #include "timestamp.hxx"
45 unsigned long int fgSimTime;
48 static struct itimerval t, ot;
49 static void (*callbackfunc)(int multi_loop);
52 // This routine catches the SIGALRM
53 void fgTimerCatch( int dummy ) {
56 // get past a compiler warning
57 warning_avoider = dummy;
59 // ignore any SIGALRM's until we come back from our EOM iteration
60 signal(SIGALRM, SIG_IGN);
62 // printf("In fgTimerCatch()\n");
64 // -1 tells the routine to use default interval rather than
65 // something dynamically calculated based on frame rate
68 signal(SIGALRM, fgTimerCatch);
72 // this routine initializes the interval timer to generate a SIGALRM
73 // after the specified interval (dt)
74 void fgTimerInit(float dt, void (*f)( int )) {
82 usec = 1000000 * ((int)dt - isec);
84 t.it_interval.tv_sec = isec;
85 t.it_interval.tv_usec = usec;
86 t.it_value.tv_sec = isec;
87 t.it_value.tv_usec = usec;
88 // printf("fgTimerInit() called\n");
89 fgTimerCatch(0); // set up for SIGALRM signal catch
90 terr = setitimer( ITIMER_REAL, &t, &ot );
92 printf("Error returned from setitimer");
96 #endif // HAVE_SETITIMER
99 // This function returns the number of microseconds since the last
100 // time it was called.
101 int fgGetTimeInterval( void ) {
103 static int inited = 0;
104 static FGTimeStamp last;
113 interval = current - last;
122 // Revision 1.6 1999/01/09 13:37:45 curt
123 // Convert fgTIMESTAMP to FGTimeStamp which holds usec instead of ms.
125 // Revision 1.5 1998/12/05 14:21:32 curt
126 // Moved struct fg_timestamp to class fgTIMESTAMP and moved it's definition
127 // to it's own file, timestamp.hxx.
129 // Revision 1.4 1998/12/04 01:32:51 curt
130 // Converted "struct fg_timestamp" to "class fgTIMESTAMP" and added some
131 // convenience inline operators.
133 // Revision 1.3 1998/04/28 01:22:18 curt
134 // Type-ified fgTIME and fgVIEW.
136 // Revision 1.2 1998/04/25 20:24:03 curt
137 // Cleaned up initialization sequence to eliminate interdependencies
138 // between sun position, lighting, and view position. This creates a
139 // valid single pass initialization path.
141 // Revision 1.1 1998/04/24 00:52:29 curt
142 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
144 // Separated out lighting calcs into their own file.
146 // Revision 1.12 1998/04/21 17:01:44 curt
147 // Fixed a problems where a pointer to a function was being passed around. In
148 // one place this functions arguments were defined as ( void ) while in another
149 // place they were defined as ( int ). The correct answer was ( int ).
151 // Prepairing for C++ integration.
153 // Revision 1.11 1998/04/03 22:12:56 curt
154 // Converting to Gnu autoconf system.
155 // Centralized time handling differences.
157 // Revision 1.10 1998/01/31 00:43:45 curt
158 // Added MetroWorks patches from Carmen Volpe.
160 // Revision 1.9 1998/01/19 19:27:21 curt
161 // Merged in make system changes from Bob Kuehne <rpk@sgi.com>
162 // This should simplify things tremendously.
164 // Revision 1.8 1998/01/19 18:40:39 curt
165 // Tons of little changes to clean up the code and to remove fatal errors
166 // when building with the c++ compiler.
168 // Revision 1.7 1997/12/30 13:06:58 curt
169 // A couple lighting tweaks ...
171 // Revision 1.6 1997/07/12 02:13:04 curt
172 // Add ftime() support for those that don't have gettimeofday()
174 // Revision 1.5 1997/06/26 19:08:38 curt
175 // Restructuring make, adding automatic "make dep" support.
177 // Revision 1.4 1997/06/25 15:39:49 curt
178 // Minor changes to compile with rsxnt/win32.
180 // Revision 1.3 1997/06/17 16:52:04 curt
181 // Timer interval stuff now uses gettimeofday() instead of ftime()
183 // Revision 1.2 1997/06/17 03:41:10 curt
184 // Nonsignal based interval timing is now working.
185 // This would be a good time to look at cleaning up the code structure a bit.
187 // Revision 1.1 1997/06/16 19:24:20 curt