1 /**************************************************************************
2 * GLUTmain.c -- top level sim routines
4 * Written by Curtis Olson for OpenGL, started May 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.
23 * (Log is kept at end of this file)
24 **************************************************************************/
35 #include <Main/GLUTkey.h>
36 #include <Main/fg_init.h>
37 #include <Main/views.h>
39 #include <Include/constants.h>
40 #include <Include/general.h>
42 #include <Aircraft/aircraft.h>
43 #include <Astro/moon.h>
44 #include <Astro/sky.h>
45 #include <Astro/stars.h>
46 #include <Astro/sun.h>
47 #include <Cockpit/cockpit.h>
48 #include <Joystick/joystick.h>
49 #include <Math/fg_geodesy.h>
50 #include <Math/mat3.h>
51 #include <Math/polar.h>
52 #include <Scenery/mesh.h>
53 #include <Scenery/scenery.h>
54 #include <Scenery/tilemgr.h>
55 #include <Time/event.h>
56 #include <Time/fg_time.h>
57 #include <Time/fg_timer.h>
58 #include <Time/sunpos.h>
59 #include <Weather/weather.h>
62 /* This is a record containing global housekeeping information */
63 struct fgGENERAL general;
66 static GLfloat win_ratio = 1.0;
67 static GLint winWidth, winHeight;
70 /* pointer to scenery structure */
71 /* static GLint scenery, runway; */
78 /* Yet another hack. This one used by the HUD code. Michele */
81 /* Yet another other hack. Used for my prototype instrument code. (Durk) */
82 int displayInstruments;
85 /**************************************************************************
86 * fgInitVisuals() -- Initialize various GL/view parameters
87 **************************************************************************/
89 static void fgInitVisuals( void ) {
94 l = &cur_light_params;
99 /* xglDisable( GL_DITHER ); */
101 /* If enabled, normal vectors specified with glNormal are scaled
102 to unit length after transformation. See glNormal. */
103 xglEnable( GL_NORMALIZE );
105 xglEnable( GL_LIGHTING );
106 xglEnable( GL_LIGHT0 );
107 xglLightfv( GL_LIGHT0, GL_POSITION, l->sun_vec );
109 xglFogi (GL_FOG_MODE, GL_LINEAR);
110 /* xglFogf (GL_FOG_START, 1.0); */
111 xglFogf (GL_FOG_END, w->visibility);
112 /* xglFogf (GL_FOG_DENSITY, w->visibility); */
113 xglHint (GL_FOG_HINT, GL_NICEST /* GL_FASTEST */ );
115 /* draw wire frame */
116 /* xglPolygonMode(GL_FRONT_AND_BACK,GL_LINE); */
120 /**************************************************************************
121 * Update the view volume, position, and orientation
122 **************************************************************************/
124 static void fgUpdateViewParams( void ) {
130 f = ¤t_aircraft.flight;
131 l = &cur_light_params;
132 t = &cur_time_params;
135 fgViewUpdate(f, v, l);
137 if (displayInstruments)
139 xglViewport(0, (GLint)(winHeight / 2 ) , (GLint)winWidth, (GLint)winHeight / 2);
140 /* Tell GL we are about to modify the projection parameters */
141 xglMatrixMode(GL_PROJECTION);
143 gluPerspective(55.0, 2.0/win_ratio, 1.0, 100000.0);
147 xglViewport(0, 0 , (GLint)winWidth, (GLint) winHeight);
148 /* Tell GL we are about to modify the projection parameters */
149 xglMatrixMode(GL_PROJECTION);
151 gluPerspective(55.0, 1.0/win_ratio, 1.0, 100000.0);
154 xglMatrixMode(GL_MODELVIEW);
157 /* set up our view volume (default) */
158 gluLookAt(v->view_pos.x, v->view_pos.y, v->view_pos.z,
159 v->view_pos.x + v->view_forward[0],
160 v->view_pos.y + v->view_forward[1],
161 v->view_pos.z + v->view_forward[2],
162 v->view_up[0], v->view_up[1], v->view_up[2]);
164 /* lock view horizontally towards sun (testing) */
165 /* gluLookAt(v->view_pos.x, v->view_pos.y, v->view_pos.z,
166 v->view_pos.x + v->surface_to_sun[0],
167 v->view_pos.y + v->surface_to_sun[1],
168 v->view_pos.z + v->surface_to_sun[2],
169 v->view_up[0], v->view_up[1], v->view_up[2]); */
171 /* lock view horizontally towards south (testing) */
172 /* gluLookAt(v->view_pos.x, v->view_pos.y, v->view_pos.z,
173 v->view_pos.x + v->surface_south[0],
174 v->view_pos.y + v->surface_south[1],
175 v->view_pos.z + v->surface_south[2],
176 v->view_up[0], v->view_up[1], v->view_up[2]); */
178 /* set the sun position */
179 xglLightfv( GL_LIGHT0, GL_POSITION, l->sun_vec );
183 /*************************************************************************
184 * Draw a basic instrument panel
185 ************************************************************************/
186 static void fgUpdateInstrViewParams( void ) {
187 xglViewport(0, 0 , (GLint)winWidth, (GLint)winHeight / 2);
189 xglMatrixMode(GL_PROJECTION);
193 gluOrtho2D(0, 640, 0, 480);
194 xglMatrixMode(GL_MODELVIEW);
198 xglColor3f(1.0, 1.0, 1.0);
201 xglDisable(GL_DEPTH_TEST);
202 xglDisable(GL_LIGHTING);
205 xglColor3f (0.5, 0.5, 0.5);
208 xglVertex2f(0.0, 0.00);
209 xglVertex2f(0.0, 480.0);
210 xglVertex2f(640.0,480.0);
211 xglVertex2f(640.0, 0.0);
214 xglRectf(0.0,0.0, 640, 480);
215 xglEnable(GL_DEPTH_TEST);
216 xglEnable(GL_LIGHTING);
217 xglMatrixMode(GL_PROJECTION);
219 xglMatrixMode(GL_MODELVIEW);
224 /**************************************************************************
225 * Update all Visuals (redraws anything graphics related)
226 **************************************************************************/
228 static void fgRenderFrame( void ) {
233 GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
235 l = &cur_light_params;
236 t = &cur_time_params;
239 /* update view volume parameters */
240 fgUpdateViewParams();
242 xglClear( GL_DEPTH_BUFFER_BIT /* | GL_COLOR_BUFFER_BIT */ );
244 /* Tell GL we are switching to model view parameters */
245 xglMatrixMode(GL_MODELVIEW);
246 /* xglLoadIdentity(); */
249 xglDisable( GL_DEPTH_TEST );
250 xglDisable( GL_LIGHTING );
251 xglDisable( GL_CULL_FACE );
252 xglDisable( GL_FOG );
253 xglShadeModel( GL_SMOOTH );
256 /* setup transformation for drawing astronomical objects */
258 /* Translate to view position */
259 xglTranslatef( v->view_pos.x, v->view_pos.y, v->view_pos.z );
260 /* Rotate based on gst (side real time) */
261 angle = t->gst * 15.041085; /* should be 15.041085, Curt thought it was 15*/
262 /* printf("Rotating astro objects by %.2f degrees\n",angle); */
263 xglRotatef( angle, 0.0, 0.0, -1.0 );
265 /* draw stars and planets */
271 /* render the moon */
272 xglEnable( GL_LIGHTING );
273 /* set lighting parameters */
274 xglLightfv(GL_LIGHT0, GL_AMBIENT, white );
275 xglLightfv(GL_LIGHT0, GL_DIFFUSE, white );
276 xglEnable( GL_CULL_FACE );
282 xglShadeModel( GL_SMOOTH );
283 xglEnable( GL_DEPTH_TEST );
285 xglFogfv (GL_FOG_COLOR, l->fog_color);
286 /* set lighting parameters */
287 xglLightfv(GL_LIGHT0, GL_AMBIENT, l->scene_ambient );
288 xglLightfv(GL_LIGHT0, GL_DIFFUSE, l->scene_diffuse );
290 /* fgSceneryRender(); */
297 /* display instruments */
298 if (displayInstruments) {
299 fgUpdateInstrViewParams();
308 /**************************************************************************
309 * Update internal time dependent calculations (i.e. flight model)
310 **************************************************************************/
312 void fgUpdateTimeDepCalcs(int multi_loop) {
318 f = ¤t_aircraft.flight;
319 t = &cur_time_params;
322 /* update the flight model */
323 if ( multi_loop < 0 ) {
324 multi_loop = DEFAULT_MULTILOOP;
327 /* printf("updating flight model x %d\n", multi_loop); */
328 fgFlightModelUpdate(FG_LARCSIM, f, multi_loop);
330 /* update the view angle */
331 for ( i = 0; i < multi_loop; i++ ) {
332 if ( fabs(v->goal_view_offset - v->view_offset) < 0.05 ) {
333 v->view_offset = v->goal_view_offset;
336 /* move v->view_offset towards v->goal_view_offset */
337 if ( v->goal_view_offset > v->view_offset ) {
338 if ( v->goal_view_offset - v->view_offset < FG_PI ) {
339 v->view_offset += 0.01;
341 v->view_offset -= 0.01;
344 if ( v->view_offset - v->goal_view_offset < FG_PI ) {
345 v->view_offset -= 0.01;
347 v->view_offset += 0.01;
350 if ( v->view_offset > FG_2PI ) {
351 v->view_offset -= FG_2PI;
352 } else if ( v->view_offset < 0 ) {
353 v->view_offset += FG_2PI;
360 void fgInitTimeDepCalcs( void ) {
361 /* initialize timer */
364 fgTimerInit( 1.0 / DEFAULT_TIMER_HZ, fgUpdateTimeDepCalcs );
370 /**************************************************************************
371 * Scenery management routines
372 **************************************************************************/
374 /* static void fgSceneryInit_OLD() { */
376 /* scenery = fgSceneryCompile_OLD();
377 runway = fgRunwayHack_OLD(0.69, 53.07);
381 /* create the scenery */
382 /* GLint fgSceneryCompile_OLD() {
385 scenery = mesh2GL(mesh_ptr_OLD);
391 /* hack in a runway */
392 /* GLint fgRunwayHack_OLD(double width, double length) {
393 static GLfloat concrete[4] = { 0.5, 0.5, 0.5, 1.0 };
394 static GLfloat line[4] = { 0.9, 0.9, 0.9, 1.0 };
397 float line_len, line_width_2, cur_pos;
399 runway = xglGenLists(1);
400 xglNewList(runway, GL_COMPILE);
403 /* xglBegin(GL_POLYGON);
404 xglMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, concrete );
405 xglNormal3f(0.0, 0.0, 1.0);
407 xglVertex3d( 0.0, -width/2.0, 0.0);
408 xglVertex3d( 0.0, width/2.0, 0.0);
409 xglVertex3d(length, width/2.0, 0.0);
410 xglVertex3d(length, -width/2.0, 0.0);
413 /* draw center line */
414 /* xglMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, line );
415 line_len = length / ( 2 * num_lines + 1);
416 printf("line_len = %.3f\n", line_len);
419 for ( i = 0; i < num_lines; i++ ) {
420 xglBegin(GL_POLYGON);
421 xglVertex3d( cur_pos, -line_width_2, 0.005);
422 xglVertex3d( cur_pos, line_width_2, 0.005);
424 xglVertex3d( cur_pos, line_width_2, 0.005);
425 xglVertex3d( cur_pos, -line_width_2, 0.005);
436 /* draw the scenery */
437 /*static void fgSceneryDraw_OLD() {
438 static float z = 32.35;
442 xglCallList(scenery);
444 printf("*** Drawing runway at %.2f\n", z);
446 xglTranslatef( -398391.28, 120070.41, 32.35);
447 xglRotatef(170.0, 0.0, 0.0, 1.0);
455 /* What should we do when we have nothing else to do? How about get
456 * ready for the next move and update the display? */
457 static void fgMainLoop( void ) {
458 static int remainder = 0;
459 int elapsed, multi_loop;
463 struct fgAIRCRAFT *a;
467 printf("Running Main Loop\n");
468 printf("======= ==== ====\n");
470 a = ¤t_aircraft;
472 t = &cur_time_params;
478 /* fgJoystickRead( &joy_x, &joy_y, &joy_b1, &joy_b2 );
479 printf( "Joystick X %f Y %f B1 %d B2 %d\n",
480 joy_x, joy_y, joy_b1, joy_b2 );
482 fgAileronSet( joy_x ); */
484 /* Calculate model iterations needed */
485 elapsed = fgGetTimeInterval();
486 printf("Time interval is = %d, previous remainder is = %d\n", elapsed,
488 printf("--> Frame rate is = %.2f\n", 1000.0 / (float)elapsed);
489 elapsed += remainder;
491 multi_loop = ((float)elapsed * 0.001) * DEFAULT_MODEL_HZ;
492 remainder = elapsed - ((multi_loop*1000) / DEFAULT_MODEL_HZ);
493 printf("Model iterations needed = %d, new remainder = %d\n", multi_loop,
496 /* Run flight model */
497 if ( ! use_signals ) {
499 fgUpdateTimeDepCalcs(multi_loop);
502 /* I'm just sticking this here for now, it should probably move
504 cur_elev = mesh_altitude(FG_Longitude * RAD_TO_ARCSEC,
505 FG_Latitude * RAD_TO_ARCSEC);
506 /* printf("Ground elevation is %.2f meters here.\n", cur_elev); */
507 /* FG_Runway_altitude = cur_elev * METER_TO_FEET; */
509 if ( FG_Altitude * FEET_TO_METER < cur_elev + 3.758099) {
510 /* set this here, otherwise if we set runway height above our
511 current height we get a really nasty bounce. */
512 FG_Runway_altitude = FG_Altitude - 3.758099;
514 /* now set aircraft altitude above ground */
515 FG_Altitude = cur_elev * METER_TO_FEET + 3.758099;
516 printf("<*> resetting altitude to %.0f meters\n",
517 FG_Altitude * FEET_TO_METER);
520 fgAircraftOutputCurrent(a);
522 /* see if we need to load any new scenery tiles */
523 /* fgTileMgrUpdate(); */
525 /* Process/manage pending events */
535 /**************************************************************************
536 * Handle new window size or exposure
537 **************************************************************************/
539 static void fgReshape( int width, int height ) {
540 /* Do this so we can call fgReshape(0,0) ourselves without having to know
541 * what the values of width & height are. */
542 if ( (height > 0) && (width > 0) ) {
543 win_ratio = (GLfloat) height / (GLfloat) width;
549 /* Inform gl of our view window size (now handled elsewhere) */
550 /* xglViewport(0, 0, (GLint)width, (GLint)height); */
552 fgUpdateViewParams();
554 /* xglClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); */
558 /**************************************************************************
560 **************************************************************************/
562 int main( int argc, char *argv[] ) {
565 f = ¤t_aircraft.flight;
567 printf("Flight Gear: Version %s\n\n", VERSION);
569 /**********************************************************************
570 * Initialize the Window/Graphics environment.
571 **********************************************************************/
574 /* initialize GLUT */
575 xglutInit(&argc, argv);
577 /* Define Display Parameters */
578 xglutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE );
580 /* Define initial window size */
581 xglutInitWindowSize(640, 480);
583 /* Initialize windows */
584 xglutCreateWindow("Flight Gear");
587 /* This is the general house keeping init routine */
590 /* This is the top level init routine which calls all the other
591 * subsystem initialization routines. If you are adding a
592 * subsystem to flight gear, its initialization call should
593 * located in this routine.*/
596 /* setup view parameters, only makes GL calls */
600 /* init timer routines, signals, etc. Arrange for an alarm
601 signal to be generated, etc. */
602 fgInitTimeDepCalcs();
605 /**********************************************************************
606 * Initialize the Event Handlers.
607 **********************************************************************/
610 /* call fgReshape() on window resizes */
611 xglutReshapeFunc( fgReshape );
613 /* call key() on keyboard event */
614 xglutKeyboardFunc( GLUTkey );
615 glutSpecialFunc( GLUTspecialkey );
617 /* call fgMainLoop() whenever there is nothing else to do */
618 xglutIdleFunc( fgMainLoop );
621 xglutDisplayFunc( fgRenderFrame );
623 /* pass control off to the GLUT event handler */
633 int printf (const char *format, ...) {}
638 /* Revision 1.50 1998/01/19 19:27:07 curt
639 /* Merged in make system changes from Bob Kuehne <rpk@sgi.com>
640 /* This should simplify things tremendously.
642 * Revision 1.49 1998/01/19 18:40:31 curt
643 * Tons of little changes to clean up the code and to remove fatal errors
644 * when building with the c++ compiler.
646 * Revision 1.48 1998/01/19 18:35:46 curt
647 * Minor tweaks and fixes for cygwin32.
649 * Revision 1.47 1998/01/13 00:23:08 curt
650 * Initial changes to support loading and management of scenery tiles. Note,
651 * there's still a fair amount of work left to be done.
653 * Revision 1.46 1998/01/08 02:22:06 curt
654 * Beginning to integrate Tile management subsystem.
656 * Revision 1.45 1998/01/07 03:18:55 curt
657 * Moved astronomical stuff from .../Src/Scenery to .../Src/Astro/
659 * Revision 1.44 1997/12/30 22:22:31 curt
660 * Further integration of event manager.
662 * Revision 1.43 1997/12/30 20:47:43 curt
663 * Integrated new event manager with subsystem initializations.
665 * Revision 1.42 1997/12/30 16:36:47 curt
666 * Merged in Durk's changes ...
668 * Revision 1.41 1997/12/30 13:06:56 curt
669 * A couple lighting tweaks ...
671 * Revision 1.40 1997/12/30 01:38:37 curt
672 * Switched back to per vertex normals and smooth shading for terrain.
674 * Revision 1.39 1997/12/22 23:45:45 curt
675 * First stab at sunset/sunrise sky glow effects.
677 * Revision 1.38 1997/12/22 04:14:28 curt
678 * Aligned sky with sun so dusk/dawn effects can be correct relative to the sun.
680 * Revision 1.37 1997/12/19 23:34:03 curt
681 * Lot's of tweaking with sky rendering and lighting.
683 * Revision 1.36 1997/12/19 16:44:57 curt
684 * Working on scene rendering order and options.
686 * Revision 1.35 1997/12/18 23:32:32 curt
687 * First stab at sky dome actually starting to look reasonable. :-)
689 * Revision 1.34 1997/12/17 23:13:34 curt
690 * Began working on rendering a sky.
692 * Revision 1.33 1997/12/15 23:54:45 curt
693 * Add xgl wrappers for debugging.
694 * Generate terrain normals on the fly.
696 * Revision 1.32 1997/12/15 20:59:08 curt
699 * Revision 1.31 1997/12/12 21:41:25 curt
700 * More light/material property tweaking ... still a ways off.
702 * Revision 1.30 1997/12/12 19:52:47 curt
703 * Working on lightling and material properties.
705 * Revision 1.29 1997/12/11 04:43:54 curt
706 * Fixed sun vector and lighting problems. I thing the moon is now lit
709 * Revision 1.28 1997/12/10 22:37:45 curt
710 * Prepended "fg" on the name of all global structures that didn't have it yet.
711 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
713 * Revision 1.27 1997/12/09 05:11:54 curt
714 * Working on tweaking lighting.
716 * Revision 1.26 1997/12/09 04:25:29 curt
717 * Working on adding a global lighting params structure.
719 * Revision 1.25 1997/12/08 22:54:09 curt
720 * Enabled GL_CULL_FACE.
722 * Revision 1.24 1997/11/25 19:25:32 curt
723 * Changes to integrate Durk's moon/sun code updates + clean up.
725 * Revision 1.23 1997/11/15 18:16:34 curt
728 * Revision 1.22 1997/10/30 12:38:41 curt
729 * Working on new scenery subsystem.
731 * Revision 1.21 1997/09/23 00:29:38 curt
732 * Tweaks to get things to compile with gcc-win32.
734 * Revision 1.20 1997/09/22 14:44:19 curt
735 * Continuing to try to align stars correctly.
737 * Revision 1.19 1997/09/18 16:20:08 curt
738 * At dusk/dawn add/remove stars in stages.
740 * Revision 1.18 1997/09/16 22:14:51 curt
741 * Tweaked time of day lighting equations. Don't draw stars during the day.
743 * Revision 1.17 1997/09/16 15:50:29 curt
744 * Working on star alignment and time issues.
746 * Revision 1.16 1997/09/13 02:00:06 curt
747 * Mostly working on stars and generating sidereal time for accurate star
750 * Revision 1.15 1997/09/05 14:17:27 curt
751 * More tweaking with stars.
753 * Revision 1.14 1997/09/05 01:35:53 curt
754 * Working on getting stars right.
756 * Revision 1.13 1997/09/04 02:17:34 curt
759 * Revision 1.12 1997/08/27 21:32:24 curt
760 * Restructured view calculation code. Added stars.
762 * Revision 1.11 1997/08/27 03:30:16 curt
763 * Changed naming scheme of basic shared structures.
765 * Revision 1.10 1997/08/25 20:27:22 curt
766 * Merged in initial HUD and Joystick code.
768 * Revision 1.9 1997/08/22 21:34:39 curt
769 * Doing a bit of reorganizing and house cleaning.
771 * Revision 1.8 1997/08/19 23:55:03 curt
772 * Worked on better simulating real lighting.
774 * Revision 1.7 1997/08/16 12:22:38 curt
775 * Working on improving the lighting/shading.
777 * Revision 1.6 1997/08/13 20:24:56 curt
778 * Changes due to changing sunpos interface.
780 * Revision 1.5 1997/08/06 21:08:32 curt
781 * Sun position now *really* works (I think) ... I still have sun time warping
782 * code in place, probably should remove it soon.
784 * Revision 1.4 1997/08/06 15:41:26 curt
785 * Working on correct sun position.
787 * Revision 1.3 1997/08/06 00:24:22 curt
788 * Working on correct real time sun lighting.
790 * Revision 1.2 1997/08/04 20:25:15 curt
791 * Organizational tweaking.
793 * Revision 1.1 1997/08/02 18:45:00 curt
794 * Renamed GLmain.c GLUTmain.c
796 * Revision 1.43 1997/08/02 16:23:47 curt
799 * Revision 1.42 1997/08/01 19:43:33 curt
800 * Making progress with coordinate system overhaul.
802 * Revision 1.41 1997/07/31 22:52:37 curt
803 * Working on redoing internal coordinate systems & scenery transformations.
805 * Revision 1.40 1997/07/30 16:12:42 curt
806 * Moved fg_random routines from Util/ to Math/
808 * Revision 1.39 1997/07/21 14:45:01 curt
811 * Revision 1.38 1997/07/19 23:04:47 curt
812 * Added an initial weather section.
814 * Revision 1.37 1997/07/19 22:34:02 curt
815 * Moved PI definitions to ../constants.h
816 * Moved random() stuff to ../Utils/ and renamed fg_random()
818 * Revision 1.36 1997/07/18 23:41:25 curt
819 * Tweaks for building with Cygnus Win32 compiler.
821 * Revision 1.35 1997/07/18 14:28:34 curt
822 * Hacked in some support for wind/turbulence.
824 * Revision 1.34 1997/07/16 20:04:48 curt
825 * Minor tweaks to aid Win32 port.
827 * Revision 1.33 1997/07/12 03:50:20 curt
828 * Added an #include <Windows32/Base.h> to help compiling for Win32
830 * Revision 1.32 1997/07/11 03:23:18 curt
831 * Solved some scenery display/orientation problems. Still have a positioning
832 * (or transformation?) problem.
834 * Revision 1.31 1997/07/11 01:29:58 curt
835 * More tweaking of terrian floor.
837 * Revision 1.30 1997/07/10 04:26:37 curt
838 * We now can interpolated ground elevation for any position in the grid. We
839 * can use this to enforce a "hard" ground. We still need to enforce some
840 * bounds checking so that we don't try to lookup data points outside the
843 * Revision 1.29 1997/07/09 21:31:12 curt
844 * Working on making the ground "hard."
846 * Revision 1.28 1997/07/08 18:20:12 curt
847 * Working on establishing a hard ground.
849 * Revision 1.27 1997/07/07 20:59:49 curt
850 * Working on scenery transformations to enable us to fly fluidly over the
851 * poles with no discontinuity/distortion in scenery.
853 * Revision 1.26 1997/07/05 20:43:34 curt
854 * renamed mat3 directory to Math so we could add other math related routines.
856 * Revision 1.25 1997/06/29 21:19:17 curt
857 * Working on scenery management system.
859 * Revision 1.24 1997/06/26 22:14:53 curt
860 * Beginning work on a scenery management system.
862 * Revision 1.23 1997/06/26 19:08:33 curt
863 * Restructuring make, adding automatic "make dep" support.
865 * Revision 1.22 1997/06/25 15:39:47 curt
866 * Minor changes to compile with rsxnt/win32.
868 * Revision 1.21 1997/06/22 21:44:41 curt
869 * Working on intergrating the VRML (subset) parser.
871 * Revision 1.20 1997/06/21 17:12:53 curt
872 * Capitalized subdirectory names.
874 * Revision 1.19 1997/06/18 04:10:31 curt
875 * A couple more runway tweaks ...
877 * Revision 1.18 1997/06/18 02:21:24 curt
880 * Revision 1.17 1997/06/17 16:51:58 curt
881 * Timer interval stuff now uses gettimeofday() instead of ftime()
883 * Revision 1.16 1997/06/17 04:19:16 curt
884 * More timer related tweaks with respect to view direction changes.
886 * Revision 1.15 1997/06/17 03:41:10 curt
887 * Nonsignal based interval timing is now working.
888 * This would be a good time to look at cleaning up the code structure a bit.
890 * Revision 1.14 1997/06/16 19:32:51 curt
891 * Starting to add general timer support.
893 * Revision 1.13 1997/06/02 03:40:06 curt
894 * A tiny bit more view tweaking.
896 * Revision 1.12 1997/06/02 03:01:38 curt
897 * Working on views (side, front, back, transitions, etc.)
899 * Revision 1.11 1997/05/31 19:16:25 curt
900 * Elevator trim added.
902 * Revision 1.10 1997/05/31 04:13:52 curt
905 * Continuing work on the LaRCsim flight model integration.
906 * Added some MSFS-like keyboard input handling.
908 * Revision 1.9 1997/05/30 19:27:01 curt
909 * The LaRCsim flight model is starting to look like it is working.
911 * Revision 1.8 1997/05/30 03:54:10 curt
912 * Made a bit more progress towards integrating the LaRCsim flight model.
914 * Revision 1.7 1997/05/29 22:39:49 curt
915 * Working on incorporating the LaRCsim flight model.
917 * Revision 1.6 1997/05/29 12:31:39 curt
918 * Minor tweaks, moving towards general flight model integration.
920 * Revision 1.5 1997/05/29 02:33:23 curt
921 * Updated to reflect changing interfaces in other "modules."
923 * Revision 1.4 1997/05/27 17:44:31 curt
924 * Renamed & rearranged variables and routines. Added some initial simple
925 * timer/alarm routines so the flight model can be updated on a regular
928 * Revision 1.3 1997/05/23 15:40:25 curt
929 * Added GNU copyright headers.
932 * Revision 1.2 1997/05/23 00:35:12 curt
933 * Trying to get fog to work ...
935 * Revision 1.1 1997/05/21 15:57:51 curt
936 * Renamed due to added GLUT support.
938 * Revision 1.3 1997/05/19 18:22:42 curt
939 * Parameter tweaking ... starting to stub in fog support.
941 * Revision 1.2 1997/05/17 00:17:34 curt
942 * Trying to stub in support for standard OpenGL.
944 * Revision 1.1 1997/05/16 16:05:52 curt