2 // fg_init.cxx -- Flight Gear top level initialization routines
4 // Written by Curtis Olson, started August 1997.
6 // Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
8 // This program is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU General Public License as
10 // published by the Free Software Foundation; either version 2 of the
11 // License, or (at your option) any later version.
13 // This program is distributed in the hope that it will be useful, but
14 // WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 // (Log is kept at end of this file)
35 #include <Include/fg_constants.h>
36 #include <Include/general.h>
38 #include <Aircraft/aircraft.h>
39 #include <Astro/moon.hxx>
40 #include <Astro/planets.hxx>
41 #include <Astro/sky.hxx>
42 #include <Astro/stars.hxx>
43 #include <Astro/sun.hxx>
44 #include <Autopilot/autopilot.h>
45 #include <Cockpit/cockpit.hxx>
46 #include <Debug/fg_debug.h>
47 #include <Joystick/joystick.h>
48 #include <Math/fg_random.h>
49 #include <Scenery/scenery.hxx>
50 #include <Scenery/tilemgr.hxx>
51 #include <Time/event.hxx>
52 #include <Time/fg_time.hxx>
53 #include <Time/light.hxx>
54 #include <Time/sunpos.hxx>
55 #include <Weather/weather.h>
57 #include "airports.hxx"
58 #include "fg_init.hxx"
59 #include "options.hxx"
63 extern const char *default_root;
66 // Set initial position
67 int fgInitPosition( void ) {
71 f = current_aircraft.flight;
74 // If nothing else is specified, default initial position is
76 FG_Longitude = ( -110.6642444 ) * DEG_TO_RAD;
77 FG_Latitude = ( 33.3528917 ) * DEG_TO_RAD;
78 FG_Runway_altitude = (3234.5 + 300);
79 FG_Altitude = FG_Runway_altitude + 3.758099;
81 // Initial Position north of the city of Globe
82 // FG_Longitude = ( -398673.28 / 3600.0 ) * DEG_TO_RAD;
83 // FG_Latitude = ( 120625.64 / 3600.0 ) * DEG_TO_RAD;
84 // FG_Longitude = ( -397867.44 / 3600.0 ) * DEG_TO_RAD;
85 // FG_Latitude = ( 119548.21 / 3600.0 ) * DEG_TO_RAD;
86 // FG_Altitude = 0.0 + 3.758099;
88 // Initial Position near where I used to live in Globe, AZ
89 // FG_Longitude = ( -398757.6 / 3600.0 ) * DEG_TO_RAD;
90 // FG_Latitude = ( 120160.0 / 3600.0 ) * DEG_TO_RAD;
91 // FG_Runway_altitude = 4000.0;
92 // FG_Altitude = FG_Runway_altitude + 3.758099;
94 // Initial Position: 10125 Jewell St. NE
95 // FG_Longitude = ( -93.15 ) * DEG_TO_RAD;
96 // FG_Latitude = ( 45.15 ) * DEG_TO_RAD;
97 // FG_Runway_altitude = 950.0;
98 // FG_Altitude = FG_Runway_altitude + 3.758099;
100 // Initial Position near KHSP (Hot Springs, VA)
101 // FG_Longitude = (-79.8338964 + 0.01) * DEG_TO_RAD;
102 // FG_Latitude = ( 37.9514564 + 0.008) * DEG_TO_RAD;
103 // FG_Runway_altitude = (3792 + 2800);
104 // FG_Altitude = FG_Runway_altitude + 3.758099;
106 // Initial Position at (SEZ) SEDONA airport
107 // FG_Longitude = (-111.7884614 + 0.01) * DEG_TO_RAD;
108 // FG_Latitude = ( 34.8486289 - 0.015) * DEG_TO_RAD;
109 // FG_Runway_altitude = (4827 + 450);
110 // FG_Altitude = FG_Runway_altitude + 3.758099;
112 // Initial Position: Somewhere near the Grand Canyon
113 // FG_Longitude = ( -112.5 ) * DEG_TO_RAD;
114 // FG_Latitude = ( 36.5 ) * DEG_TO_RAD;
115 // FG_Runway_altitude = 8000.0;
116 // FG_Altitude = FG_Runway_altitude + 3.758099;
118 // Initial Position: Jim Brennon's Kingmont Observatory
119 // FG_Longitude = ( -121.1131667 ) * DEG_TO_RAD;
120 // FG_Latitude = ( 38.8293917 ) * DEG_TO_RAD;
121 // FG_Runway_altitude = 920.0;
122 // FG_Altitude = FG_Runway_altitude + 3.758099;
124 // probably interesting for european team members
125 // That is: If I can get the scenery to work -;) (Durk)
127 // Eclipse Watching w73.5 n10 (approx) 18:00 UT
128 // FG_Longitude = ( -73.5 ) * DEG_TO_RAD;
129 // FG_Latitude = ( 10.0 ) * DEG_TO_RAD;
130 // FG_Runway_altitude = 0.0;
131 // FG_Altitude = FG_Runway_altitude + 3.758099;
134 // FG_Longitude = ( 8.5 ) * DEG_TO_RAD;
135 // FG_Latitude = ( 47.5 ) * DEG_TO_RAD;
136 FG_Runway_altitude = ( 6000 );
137 FG_Altitude = FG_Runway_altitude + 3.758099;
139 if ( strlen(o->airport_id) ) {
143 fgPrintf( FG_GENERAL, FG_INFO,
144 "Attempting to set starting position from airport code %s.\n",
147 airports.load("Airports");
148 a = airports.search(o->airport_id);
149 if ( (fabs(a.longitude) < FG_EPSILON) &&
150 (fabs(a.latitude) < FG_EPSILON) &&
151 (fabs(a.elevation) < FG_EPSILON) ) {
152 fgPrintf( FG_GENERAL, FG_EXIT,
153 "Failed to find %s in database.\n", o->airport_id);
155 FG_Longitude = ( a.longitude ) * DEG_TO_RAD;
156 FG_Latitude = ( a.latitude ) * DEG_TO_RAD;
157 FG_Runway_altitude = ( a.elevation + 200 );
158 FG_Altitude = FG_Runway_altitude + 3.758099;
162 fgPrintf( FG_GENERAL, FG_INFO,
163 "Initial position is: (%.4f, %.4f, %.2f)\n",
164 FG_Longitude * RAD_TO_DEG, FG_Latitude * RAD_TO_DEG,
165 FG_Altitude * FEET_TO_METER);
171 // General house keeping initializations
172 int fgInitGeneral( void ) {
178 o = ¤t_options;
180 fgPrintf( FG_GENERAL, FG_INFO, "General Initialization\n" );
181 fgPrintf( FG_GENERAL, FG_INFO, "======= ==============\n" );
183 g->glVendor = glGetString ( GL_VENDOR );
184 g->glRenderer = glGetString ( GL_RENDERER );
185 g->glVersion = glGetString ( GL_VERSION );
187 if ( !strlen(o->fg_root) ) {
188 // No root path set? Then assume, we will exit if this is
189 // wrong when looking for support files.
190 fgPrintf( FG_GENERAL, FG_EXIT, "%s %s\n",
191 "Cannot continue without environment variable FG_ROOT",
194 fgPrintf( FG_GENERAL, FG_INFO, "FG_ROOT = %s\n\n", o->fg_root);
196 // prime the frame rate counter pump
197 for ( i = 0; i < FG_FRAME_RATE_HISTORY; i++ ) {
205 // This is the top level init routine which calls all the other
206 // initialization routines. If you are adding a subsystem to flight
207 // gear, its initialization call should located in this routine.
208 // Returns non-zero if a problem encountered.
209 int fgInitSubsystems( void ) {
217 l = &cur_light_params;
218 t = &cur_time_params;
221 fgPrintf( FG_GENERAL, FG_INFO, "Initialize Subsystems\n");
222 fgPrintf( FG_GENERAL, FG_INFO, "========== ==========\n");
224 // seed the random number generater
227 // The following section sets up the flight model EOM parameters
228 // and should really be read in from one or more files.
230 // Must happen before any of the flight model or control
231 // parameters are set
233 fgAircraftInit(); // In the future this might not be the case.
234 f = current_aircraft.flight;
236 // set the initial position
240 FG_V_north = 0.0; // 7.287719E+00
241 FG_V_east = 0.0; // 1.521770E+03
242 FG_V_down = 0.0; // -1.265722E-05
244 // Initial Orientation
245 FG_Phi = -2.658474E-06;
246 FG_Theta = 7.401790E-03;
247 FG_Psi = 270.0 * DEG_TO_RAD;
249 // Initial Angular B rates
250 FG_P_body = 7.206685E-05;
251 FG_Q_body = 0.000000E+00;
252 FG_R_body = 9.492658E-05;
254 FG_Earth_position_angle = 0.000000E+00;
256 // Mass properties and geometry values
257 FG_Mass = 8.547270E+01;
258 FG_I_xx = 1.048000E+03;
259 FG_I_yy = 3.000000E+03;
260 FG_I_zz = 3.530000E+03;
261 FG_I_xz = 0.000000E+00;
263 // CG position w.r.t. ref. point
264 FG_Dx_cg = 0.000000E+00;
265 FG_Dy_cg = 0.000000E+00;
266 FG_Dz_cg = 0.000000E+00;
268 // Initialize the event manager
269 global_events.Init();
271 // Output event stats every 60 seconds
272 global_events.Register( "fgEventPrintStats()", fgEventPrintStats,
273 FG_EVENT_READY, 60000 );
275 // Initialize the time dependent variables
279 // Initialize view parameters
282 v->UpdateWorldToEye(f);
284 // Initialize the orbital elements of sun, moon and mayor planets
285 fgSolarSystemInit(*t);
287 // Initialize the Stars subsystem
288 if( fgStarsInit() ) {
289 // Stars initialized ok.
291 fgPrintf( FG_GENERAL, FG_EXIT, "Error in Stars initialization!\n" );
294 // Initialize the planetary subsystem
295 global_events.Register( "fgPlanetsInit()", fgPlanetsInit,
296 FG_EVENT_READY, 600000);
298 // Initialize the sun's position
299 global_events.Register( "fgSunInit()", fgSunInit,
300 FG_EVENT_READY, 30000 );
302 // Intialize the moon's position
303 global_events.Register( "fgMoonInit()", fgMoonInit,
304 FG_EVENT_READY, 600000 );
306 // fgUpdateSunPos() needs a few position and view parameters set
307 // so it can calculate local relative sun angle and a few other
308 // things for correctly orienting the sky.
311 // Initialize Lighting interpolation tables
314 // update the lighting parameters (based on sun angle)
315 global_events.Register( "fgLightUpdate()", fgLightUpdate,
316 FG_EVENT_READY, 30000 );
318 // Initialize the weather modeling subsystem
321 // update the weather for our current position
322 global_events.Register( "fgWeatherUpdate()", fgWeatherUpdate,
323 FG_EVENT_READY, 120000 );
325 // Initialize the Cockpit subsystem
326 if( fgCockpitInit( ¤t_aircraft )) {
327 // Cockpit initialized ok.
329 fgPrintf( FG_GENERAL, FG_EXIT, "Error in Cockpit initialization!\n" );
332 // Initialize the "sky"
335 // Initialize the Scenery Management subsystem
336 if ( fgSceneryInit() ) {
337 // Scenery initialized ok.
339 fgPrintf( FG_GENERAL, FG_EXIT, "Error in Scenery initialization!\n" );
343 if( fgTileMgrInit() ) {
344 // Load the local scenery data
347 fgPrintf( FG_GENERAL, FG_EXIT,
348 "Error in Tile Manager initialization!\n" );
351 // I'm just sticking this here for now, it should probably move
353 cur_elev = FG_Runway_altitude * FEET_TO_METER;
354 if ( cur_elev > -9990.0 ) {
355 FG_Runway_altitude = cur_elev * METER_TO_FEET;
358 if ( FG_Altitude < FG_Runway_altitude ) {
359 FG_Altitude = FG_Runway_altitude + 3.758099;
362 fgPrintf( FG_GENERAL, FG_INFO,
363 "Updated position (after elevation adj): (%.4f, %.4f, %.2f)\n",
364 FG_Latitude * RAD_TO_DEG, FG_Longitude * RAD_TO_DEG,
365 FG_Altitude * FEET_TO_METER);
366 // end of thing that I just stuck in that I should probably move
368 // Initialize the flight model subsystem data structures base on
371 fgFlightModelInit( FG_LARCSIM, f, 1.0 / DEFAULT_MODEL_HZ );
374 if (fgJoystickInit(0) ) {
375 // Joystick initialized ok.
377 fgPrintf( FG_GENERAL, FG_EXIT, "Error in Joystick initialization!\n" );
380 // Autopilot init added here, by Jeff Goeke-Smith
381 fgAPInit(¤t_aircraft);
383 fgPrintf(FG_GENERAL, FG_INFO,"\n");
390 // Revision 1.22 1998/07/04 00:52:25 curt
391 // Add my own version of gluLookAt() (which is nearly identical to the
392 // Mesa/glu version.) But, by calculating the Model View matrix our selves
393 // we can save this matrix without having to read it back in from the video
394 // card. This hopefully allows us to save a few cpu cycles when rendering
395 // out the fragments because we can just use glLoadMatrixd() with the
396 // precalculated matrix for each tile rather than doing a push(), translate(),
397 // pop() for every fragment.
399 // Panel status defaults to off for now until it gets a bit more developed.
401 // Extract OpenGL driver info on initialization.
403 // Revision 1.21 1998/06/27 16:54:33 curt
404 // Replaced "extern displayInstruments" with a entry in fgOPTIONS.
405 // Don't change the view port when displaying the panel.
407 // Revision 1.20 1998/06/17 21:35:12 curt
408 // Refined conditional audio support compilation.
409 // Moved texture parameter setup calls to ../Scenery/materials.cxx
410 // #include <string.h> before various STL includes.
411 // Make HUD default state be enabled.
413 // Revision 1.19 1998/06/08 17:57:05 curt
414 // Minor sound/startup position tweaks.
416 // Revision 1.18 1998/06/03 00:47:14 curt
417 // Updated to compile in audio support if OSS available.
418 // Updated for new version of Steve's audio library.
419 // STL includes don't use .h
420 // Small view optimizations.
422 // Revision 1.17 1998/06/01 17:54:42 curt
423 // Added Linux audio support.
424 // avoid glClear( COLOR_BUFFER_BIT ) when not using it to set the sky color.
427 // Revision 1.16 1998/05/29 20:37:24 curt
428 // Tweaked material properties & lighting a bit in GLUTmain.cxx.
429 // Read airport list into a "map" STL for dynamic list sizing and fast tree
432 // Revision 1.15 1998/05/22 21:28:53 curt
433 // Modifications to use the new fgEVENT_MGR class.
435 // Revision 1.14 1998/05/20 20:51:35 curt
436 // Tweaked smooth shaded texture lighting properties.
437 // Converted fgLIGHT to a C++ class.
439 // Revision 1.13 1998/05/16 13:08:35 curt
440 // C++ - ified views.[ch]xx
441 // Shuffled some additional view parameters into the fgVIEW class.
442 // Changed tile-radius to tile-diameter because it is a much better
444 // Added a WORLD_TO_EYE transformation to views.cxx. This allows us
445 // to transform world space to eye space for view frustum culling.
447 // Revision 1.12 1998/05/13 18:29:58 curt
448 // Added a keyboard binding to dynamically adjust field of view.
449 // Added a command line option to specify fov.
450 // Adjusted terrain color.
451 // Root path info moved to fgOPTIONS.
452 // Added ability to parse options out of a config file.
454 // Revision 1.11 1998/05/07 23:14:15 curt
455 // Added "D" key binding to set autopilot heading.
456 // Made frame rate calculation average out over last 10 frames.
457 // Borland C++ floating point exception workaround.
458 // Added a --tile-radius=n option.
460 // Revision 1.10 1998/05/06 03:16:24 curt
461 // Added an averaged global frame rate counter.
462 // Added an option to control tile radius.
464 // Revision 1.9 1998/05/03 00:47:31 curt
465 // Added an option to enable/disable full-screen mode.
467 // Revision 1.8 1998/04/30 12:34:18 curt
468 // Added command line rendering options:
469 // enable/disable fog/haze
470 // specify smooth/flat shading
471 // disable sky blending and just use a solid color
472 // enable wireframe drawing mode
474 // Revision 1.7 1998/04/28 01:20:22 curt
475 // Type-ified fgTIME and fgVIEW.
476 // Added a command line option to disable textures.
478 // Revision 1.6 1998/04/26 05:10:03 curt
479 // "struct fgLIGHT" -> "fgLIGHT" because fgLIGHT is typedef'd.
481 // Revision 1.5 1998/04/25 22:06:30 curt
482 // Edited cvs log messages in source files ... bad bad bad!
484 // Revision 1.4 1998/04/25 20:24:01 curt
485 // Cleaned up initialization sequence to eliminate interdependencies
486 // between sun position, lighting, and view position. This creates a
487 // valid single pass initialization path.
489 // Revision 1.3 1998/04/25 15:11:11 curt
490 // Added an command line option to set starting position based on airport ID.
492 // Revision 1.2 1998/04/24 00:49:20 curt
493 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
494 // Trying out some different option parsing code.
495 // Some code reorganization.
497 // Revision 1.1 1998/04/22 13:25:44 curt
498 // C++ - ifing the code.
499 // Starting a bit of reorganization of lighting code.
501 // Revision 1.56 1998/04/18 04:11:28 curt
502 // Moved fg_debug to it's own library, added zlib support.
504 // Revision 1.55 1998/04/14 02:21:03 curt
505 // Incorporated autopilot heading hold contributed by: Jeff Goeke-Smith
506 // <jgoeke@voyager.net>
508 // Revision 1.54 1998/04/08 23:35:36 curt
509 // Tweaks to Gnu automake/autoconf system.
511 // Revision 1.53 1998/04/03 22:09:06 curt
512 // Converting to Gnu autoconf system.
514 // Revision 1.52 1998/03/23 21:24:38 curt
515 // Source code formating tweaks.
517 // Revision 1.51 1998/03/14 00:31:22 curt
518 // Beginning initial terrain texturing experiments.
520 // Revision 1.50 1998/03/09 22:46:19 curt
523 // Revision 1.49 1998/02/23 19:07:59 curt
524 // Incorporated Durk's Astro/ tweaks. Includes unifying the sun position
525 // calculation code between sun display, and other FG sections that use this
526 // for things like lighting.
528 // Revision 1.48 1998/02/21 14:53:15 curt
529 // Added Charlie's HUD changes.
531 // Revision 1.47 1998/02/19 13:05:53 curt
532 // Incorporated some HUD tweaks from Michelle America.
533 // Tweaked the sky's sunset/rise colors.
534 // Other misc. tweaks.
536 // Revision 1.46 1998/02/18 15:07:06 curt
537 // Tweaks to build with SGI OpenGL (and therefor hopefully other accelerated
538 // drivers will work.)
540 // Revision 1.45 1998/02/16 13:39:43 curt
541 // Miscellaneous weekend tweaks. Fixed? a cache problem that caused whole
542 // tiles to occasionally be missing.
544 // Revision 1.44 1998/02/12 21:59:50 curt
545 // Incorporated code changes contributed by Charlie Hotchkiss
546 // <chotchkiss@namg.us.anritsu.com>
548 // Revision 1.43 1998/02/11 02:50:40 curt
551 // Revision 1.42 1998/02/09 22:56:58 curt
552 // Removed "depend" files from cvs control. Other minor make tweaks.
554 // Revision 1.41 1998/02/09 15:07:50 curt
557 // Revision 1.40 1998/02/07 15:29:44 curt
558 // Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
559 // <chotchkiss@namg.us.anritsu.com>
561 // Revision 1.39 1998/02/03 23:20:25 curt
562 // Lots of little tweaks to fix various consistency problems discovered by
563 // Solaris' CC. Fixed a bug in fg_debug.c with how the fgPrintf() wrapper
564 // passed arguments along to the real printf(). Also incorporated HUD changes
565 // by Michele America.
567 // Revision 1.38 1998/02/02 20:53:58 curt
568 // Incorporated Durk's changes.
570 // Revision 1.37 1998/02/01 03:39:54 curt
573 // Revision 1.36 1998/01/31 00:43:13 curt
574 // Added MetroWorks patches from Carmen Volpe.
576 // Revision 1.35 1998/01/27 00:47:57 curt
577 // Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
578 // system and commandline/config file processing code.
580 // Revision 1.34 1998/01/22 02:59:37 curt
581 // Changed #ifdef FILE_H to #ifdef _FILE_H
583 // Revision 1.33 1998/01/21 21:11:34 curt
586 // Revision 1.32 1998/01/19 19:27:08 curt
587 // Merged in make system changes from Bob Kuehne <rpk@sgi.com>
588 // This should simplify things tremendously.
590 // Revision 1.31 1998/01/19 18:40:32 curt
591 // Tons of little changes to clean up the code and to remove fatal errors
592 // when building with the c++ compiler.
594 // Revision 1.30 1998/01/13 00:23:09 curt
595 // Initial changes to support loading and management of scenery tiles. Note,
596 // there's still a fair amount of work left to be done.
598 // Revision 1.29 1998/01/08 02:22:08 curt
599 // Beginning to integrate Tile management subsystem.
601 // Revision 1.28 1998/01/07 03:18:58 curt
602 // Moved astronomical stuff from .../Src/Scenery to .../Src/Astro/
604 // Revision 1.27 1998/01/05 18:44:35 curt
605 // Add an option to advance/decrease time from keyboard.
607 // Revision 1.26 1997/12/30 23:09:04 curt
608 // Tweaking initialization sequences.
610 // Revision 1.25 1997/12/30 22:22:33 curt
611 // Further integration of event manager.
613 // Revision 1.24 1997/12/30 20:47:44 curt
614 // Integrated new event manager with subsystem initializations.
616 // Revision 1.23 1997/12/30 16:36:50 curt
617 // Merged in Durk's changes ...
619 // Revision 1.22 1997/12/19 23:34:05 curt
620 // Lot's of tweaking with sky rendering and lighting.
622 // Revision 1.21 1997/12/19 16:45:00 curt
623 // Working on scene rendering order and options.
625 // Revision 1.20 1997/12/18 23:32:33 curt
626 // First stab at sky dome actually starting to look reasonable. :-)
628 // Revision 1.19 1997/12/17 23:13:36 curt
629 // Began working on rendering a sky.
631 // Revision 1.18 1997/12/15 23:54:49 curt
632 // Add xgl wrappers for debugging.
633 // Generate terrain normals on the fly.
635 // Revision 1.17 1997/12/15 20:59:09 curt
638 // Revision 1.16 1997/12/12 19:52:48 curt
639 // Working on lightling and material properties.
641 // Revision 1.15 1997/12/11 04:43:55 curt
642 // Fixed sun vector and lighting problems. I thing the moon is now lit
645 // Revision 1.14 1997/12/10 22:37:47 curt
646 // Prepended "fg" on the name of all global structures that didn't have it yet.
647 // i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
649 // Revision 1.13 1997/11/25 19:25:32 curt
650 // Changes to integrate Durk's moon/sun code updates + clean up.
652 // Revision 1.12 1997/11/15 18:16:35 curt
655 // Revision 1.11 1997/10/30 12:38:42 curt
656 // Working on new scenery subsystem.
658 // Revision 1.10 1997/10/25 03:24:23 curt
659 // Incorporated sun, moon, and star positioning code contributed by Durk Talsma.
661 // Revision 1.9 1997/09/23 00:29:39 curt
662 // Tweaks to get things to compile with gcc-win32.
664 // Revision 1.8 1997/09/22 14:44:20 curt
665 // Continuing to try to align stars correctly.
667 // Revision 1.7 1997/09/16 15:50:30 curt
668 // Working on star alignment and time issues.
670 // Revision 1.6 1997/09/05 14:17:30 curt
671 // More tweaking with stars.
673 // Revision 1.5 1997/09/04 02:17:36 curt
676 // Revision 1.4 1997/08/27 21:32:26 curt
677 // Restructured view calculation code. Added stars.
679 // Revision 1.3 1997/08/27 03:30:19 curt
680 // Changed naming scheme of basic shared structures.
682 // Revision 1.2 1997/08/25 20:27:23 curt
683 // Merged in initial HUD and Joystick code.
685 // Revision 1.1 1997/08/23 01:46:20 curt