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 **************************************************************************/
38 #include "../constants.h"
39 #include "../general.h"
41 #include "../Aircraft/aircraft.h"
42 #include "../Cockpit/cockpit.h"
43 #include "../Joystick/joystick.h"
44 #include "../Math/fg_geodesy.h"
45 #include "../Math/mat3.h"
46 #include "../Math/polar.h"
47 #include "../Scenery/mesh.h"
48 #include "../Scenery/scenery.h"
49 #include "../Time/fg_time.h"
50 #include "../Time/fg_timer.h"
51 #include "../Time/sunpos.h"
52 #include "../Weather/weather.h"
55 /* This is a record containing all the info for the aircraft currently
57 struct AIRCRAFT current_aircraft;
59 /* This is a record containing global housekeeping information */
60 struct GENERAL general;
62 /* This is a record containing current weather info */
63 struct WEATHER current_weather;
65 /* This is a record containing current view parameters */
66 struct VIEW current_view;
69 static GLfloat win_ratio = 1.0;
72 static GLfloat sun_vec[4] = {1.0, 0.0, 0.0, 0.0 };
74 /* if the 4th field is 0.0, this specifies a direction ... */
75 /* clear color (sky) */
76 static GLfloat fgClearColor[4] = {0.60, 0.60, 0.90, 1.0};
78 static GLfloat fgFogColor[4] = {0.65, 0.65, 0.85, 1.0};
81 /* extern struct mesh *mesh_ptr; */
82 /* Function prototypes */
83 /* GLint fgSceneryCompile_OLD(); */
84 /* static void fgSceneryDraw_OLD(); */
86 /* pointer to scenery structure */
87 /* static GLint scenery, runway; */
90 /* double view_offset = 0.0;
91 double goal_view_offset = 0.0; */
98 /* Yet another hack. This one used by the HUD code. Michele */
102 /**************************************************************************
103 * fgInitVisuals() -- Initialize various GL/view parameters
104 **************************************************************************/
106 static void fgInitVisuals() {
109 w = ¤t_weather;
111 glEnable( GL_DEPTH_TEST );
112 /* glFrontFace(GL_CW); */
113 glEnable( GL_CULL_FACE );
115 /* If enabled, normal vectors specified with glNormal are scaled
116 to unit length after transformation. See glNormal. */
117 glEnable( GL_NORMALIZE );
119 glLightfv( GL_LIGHT0, GL_POSITION, sun_vec );
120 glEnable( GL_LIGHTING );
121 glEnable( GL_LIGHT0 );
123 glShadeModel( GL_FLAT ); /* glShadeModel( GL_SMOOTH ); */
126 glFogi (GL_FOG_MODE, GL_LINEAR);
127 /* glFogf (GL_FOG_START, 1.0); */
128 glFogf (GL_FOG_END, w->visibility);
129 glFogfv (GL_FOG_COLOR, fgFogColor);
130 /* glFogf (GL_FOG_DENSITY, w->visibility); */
131 /* glHint (GL_FOG_HINT, GL_FASTEST); */
133 glClearColor(fgClearColor[0], fgClearColor[1], fgClearColor[2],
138 /**************************************************************************
139 * Update the view volume, position, and orientation
140 **************************************************************************/
142 static void fgUpdateViewParams() {
147 double sun_angle, temp, ambient, diffuse, sky;
148 GLfloat color[4] = { 1.0, 1.0, 0.50, 1.0 };
149 GLfloat amb[3], diff[3], fog[4], clear[4];
151 f = ¤t_aircraft.flight;
152 t = &cur_time_params;
157 /* Tell GL we are about to modify the projection parameters */
158 glMatrixMode(GL_PROJECTION);
160 gluPerspective(45.0, 1.0/win_ratio, 1.0, 200000.0);
162 glMatrixMode(GL_MODELVIEW);
165 /* set up our view volume */
166 gluLookAt(v->view_pos.x, v->view_pos.y, v->view_pos.z,
167 v->view_pos.x + v->view_forward[0],
168 v->view_pos.y + v->view_forward[1],
169 v->view_pos.z + v->view_forward[2],
170 v->view_up[0], v->view_up[1], v->view_up[2]);
172 /* set the sun position */
173 glLightfv( GL_LIGHT0, GL_POSITION, sun_vec );
175 /* calculate lighting parameters based on sun's relative angle to
177 MAT3_COPY_VEC(nup, v->local_up);
178 nsun[0] = t->fg_sunpos.x;
179 nsun[1] = t->fg_sunpos.y;
180 nsun[2] = t->fg_sunpos.z;
181 MAT3_NORMALIZE_VEC(nup, temp);
182 MAT3_NORMALIZE_VEC(nsun, temp);
184 sun_angle = acos(MAT3_DOT_PRODUCT(nup, nsun));
185 printf("SUN ANGLE relative to current location = %.3f rads.\n", sun_angle);
187 /* ya kind'a have to plot this to see the magic */
188 ambient = 0.4 * pow(2.4, -sun_angle*sun_angle*sun_angle*sun_angle/3.0);
189 diffuse = 0.4 * cos(0.6*sun_angle*sun_angle);
190 sky = 0.85 * pow(1.6, -sun_angle*sun_angle*sun_angle*sun_angle/2.0) + 0.15;
192 if ( ambient < 0.1 ) { ambient = 0.1; }
193 if ( diffuse < 0.0 ) { diffuse = 0.0; }
195 if ( sky < 0.0 ) { sky = 0.0; }
197 amb[0] = color[0] * ambient;
198 amb[1] = color[1] * ambient;
199 amb[2] = color[2] * ambient;
201 diff[0] = color[0] * diffuse;
202 diff[1] = color[1] * diffuse;
203 diff[2] = color[2] * diffuse;
205 /* set lighting parameters */
206 glLightfv(GL_LIGHT0, GL_AMBIENT, amb );
207 glLightfv(GL_LIGHT0, GL_DIFFUSE, diff );
210 fog[0] = fgFogColor[0] * (ambient + diffuse);
211 fog[1] = fgFogColor[1] * (ambient + diffuse);
212 fog[2] = fgFogColor[2] * (ambient + diffuse);
213 fog[3] = fgFogColor[3];
214 glFogfv (GL_FOG_COLOR, fog);
217 clear[0] = fgClearColor[0] * sky;
218 clear[1] = fgClearColor[1] * sky;
219 clear[2] = fgClearColor[2] * sky;
220 clear[3] = fgClearColor[3];
221 glClearColor(clear[0], clear[1], clear[2], clear[3]);
225 /**************************************************************************
226 * Update all Visuals (redraws anything graphics related)
227 **************************************************************************/
229 static void fgUpdateVisuals( void ) {
230 /* update view volume parameters */
231 fgUpdateViewParams();
233 glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
235 /* Tell GL we are switching to model view parameters */
236 glMatrixMode(GL_MODELVIEW);
237 /* glLoadIdentity(); */
254 /**************************************************************************
255 * Update internal time dependent calculations (i.e. flight model)
256 **************************************************************************/
258 void fgUpdateTimeDepCalcs(int multi_loop) {
264 f = ¤t_aircraft.flight;
265 t = &cur_time_params;
268 /* update the flight model */
269 if ( multi_loop < 0 ) {
270 multi_loop = DEFAULT_MULTILOOP;
273 /* printf("updating flight model x %d\n", multi_loop); */
274 fgFlightModelUpdate(FG_LARCSIM, f, multi_loop);
276 /* refresh shared sun position and sun_vec */
279 /* the sun position has to be translated just like everything else */
280 sun_vec[0] = t->fg_sunpos.x - scenery.center.x;
281 sun_vec[1] = t->fg_sunpos.y - scenery.center.y;
282 sun_vec[2] = t->fg_sunpos.z - scenery.center.z;
283 /* make this a directional light source only */
286 /* update the view angle */
287 for ( i = 0; i < multi_loop; i++ ) {
288 if ( fabs(v->goal_view_offset - v->view_offset) < 0.05 ) {
289 v->view_offset = v->goal_view_offset;
292 /* move v->view_offset towards v->goal_view_offset */
293 if ( v->goal_view_offset > v->view_offset ) {
294 if ( v->goal_view_offset - v->view_offset < FG_PI ) {
295 v->view_offset += 0.01;
297 v->view_offset -= 0.01;
300 if ( v->view_offset - v->goal_view_offset < FG_PI ) {
301 v->view_offset -= 0.01;
303 v->view_offset += 0.01;
306 if ( v->view_offset > FG_2PI ) {
307 v->view_offset -= FG_2PI;
308 } else if ( v->view_offset < 0 ) {
309 v->view_offset += FG_2PI;
316 void fgInitTimeDepCalcs() {
317 /* initialize timer */
320 fgTimerInit( 1.0 / DEFAULT_TIMER_HZ, fgUpdateTimeDepCalcs );
326 /**************************************************************************
327 * Scenery management routines
328 **************************************************************************/
330 /* static void fgSceneryInit_OLD() { */
332 /* scenery = fgSceneryCompile_OLD();
333 runway = fgRunwayHack_OLD(0.69, 53.07);
337 /* create the scenery */
338 /* GLint fgSceneryCompile_OLD() {
341 scenery = mesh2GL(mesh_ptr_OLD);
347 /* hack in a runway */
348 /* GLint fgRunwayHack_OLD(double width, double length) {
349 static GLfloat concrete[4] = { 0.5, 0.5, 0.5, 1.0 };
350 static GLfloat line[4] = { 0.9, 0.9, 0.9, 1.0 };
353 float line_len, line_width_2, cur_pos;
355 runway = glGenLists(1);
356 glNewList(runway, GL_COMPILE);
359 /* glBegin(GL_POLYGON);
360 glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, concrete );
361 glNormal3f(0.0, 0.0, 1.0);
363 glVertex3d( 0.0, -width/2.0, 0.0);
364 glVertex3d( 0.0, width/2.0, 0.0);
365 glVertex3d(length, width/2.0, 0.0);
366 glVertex3d(length, -width/2.0, 0.0);
369 /* draw center line */
370 /* glMaterialfv( GL_FRONT, GL_AMBIENT_AND_DIFFUSE, line );
371 line_len = length / ( 2 * num_lines + 1);
372 printf("line_len = %.3f\n", line_len);
375 for ( i = 0; i < num_lines; i++ ) {
377 glVertex3d( cur_pos, -line_width_2, 0.005);
378 glVertex3d( cur_pos, line_width_2, 0.005);
380 glVertex3d( cur_pos, line_width_2, 0.005);
381 glVertex3d( cur_pos, -line_width_2, 0.005);
392 /* draw the scenery */
393 /*static void fgSceneryDraw_OLD() {
394 static float z = 32.35;
400 printf("*** Drawing runway at %.2f\n", z);
402 glTranslatef( -398391.28, 120070.41, 32.35);
403 glRotatef(170.0, 0.0, 0.0, 1.0);
410 /* What should we do when we have nothing else to do? How about get
411 * ready for the next move and update the display? */
412 static void fgMainLoop( void ) {
413 static int remainder = 0;
414 int elapsed, multi_loop;
420 f = ¤t_aircraft.flight;
423 /* fgJoystickRead( &joy_x, &joy_y, &joy_b1, &joy_b2 ); */
424 /* printf( "Joystick X %f Y %f B1 %d B2 %d\n",
425 joy_x, joy_y, joy_b1, joy_b2 );
427 fgAileronSet( joy_x ); */
429 /* update the weather for our current position */
430 fgWeatherUpdate(FG_Longitude * RAD_TO_ARCSEC,
431 FG_Latitude * RAD_TO_ARCSEC,
432 FG_Altitude * FEET_TO_METER);
434 /* Calculate model iterations needed */
435 elapsed = fgGetTimeInterval();
436 printf("Time interval is = %d, previous remainder is = %d\n", elapsed,
438 printf("--> Frame rate is = %.2f\n", 1000.0 / (float)elapsed);
439 elapsed += remainder;
441 multi_loop = ((float)elapsed * 0.001) * DEFAULT_MODEL_HZ;
442 remainder = elapsed - ((multi_loop*1000) / DEFAULT_MODEL_HZ);
443 printf("Model iterations needed = %d, new remainder = %d\n", multi_loop,
446 if ( ! use_signals ) {
448 fgUpdateTimeDepCalcs(multi_loop);
451 /* I'm just sticking this here for now, it should probably move
453 cur_elev = mesh_altitude(FG_Longitude * RAD_TO_ARCSEC,
454 FG_Latitude * RAD_TO_ARCSEC);
455 printf("Ground elevation is %.2f meters here.\n", cur_elev);
456 /* FG_Runway_altitude = cur_elev * METER_TO_FEET; */
458 if ( FG_Altitude * FEET_TO_METER < cur_elev + 3.758099) {
459 /* set this here, otherwise if we set runway height above our
460 current height we get a really nasty bounce. */
461 FG_Runway_altitude = FG_Altitude - 3.758099;
463 /* now set aircraft altitude above ground */
464 FG_Altitude = cur_elev * METER_TO_FEET + 3.758099;
465 printf("<*> resetting altitude to %.0f meters\n",
466 FG_Altitude * FEET_TO_METER);
476 /**************************************************************************
477 * Handle new window size or exposure
478 **************************************************************************/
480 static void fgReshape( int width, int height ) {
481 /* Do this so we can call fgReshape(0,0) ourselves without having to know
482 * what the values of width & height are. */
483 if ( (height > 0) && (width > 0) ) {
484 win_ratio = (GLfloat) height / (GLfloat) width;
487 /* Inform gl of our view window size */
488 glViewport(0, 0, (GLint)width, (GLint)height);
490 fgUpdateViewParams();
492 glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
496 /**************************************************************************
498 **************************************************************************/
500 int main( int argc, char *argv[] ) {
503 f = ¤t_aircraft.flight;
505 printf("Flight Gear: prototype version %s\n\n", VERSION);
507 /**********************************************************************
508 * Initialize the Window/Graphics environment.
509 **********************************************************************/
512 /* initialize GLUT */
513 glutInit(&argc, argv);
515 /* Define Display Parameters */
516 glutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE );
518 /* Define initial window size */
519 glutInitWindowSize(640, 480);
521 /* Initialize windows */
522 glutCreateWindow("Flight Gear");
525 /* This is the general house keeping init routine */
528 /* This is the top level init routine which calls all the other
529 * subsystem initialization routines. If you are adding a
530 * subsystem to flight gear, its initialization call should
531 * located in this routine.*/
534 /* setup view parameters, only makes GL calls */
538 /* init timer routines, signals, etc. Arrange for an alarm
539 signal to be generated, etc. */
540 fgInitTimeDepCalcs();
543 /**********************************************************************
544 * Initialize the Event Handlers.
545 **********************************************************************/
548 /* call fgReshape() on window resizes */
549 glutReshapeFunc( fgReshape );
551 /* call key() on keyboard event */
552 glutKeyboardFunc( GLUTkey );
553 glutSpecialFunc( GLUTspecialkey );
555 /* call fgMainLoop() whenever there is nothing else to do */
556 glutIdleFunc( fgMainLoop );
559 glutDisplayFunc( fgUpdateVisuals );
561 /* pass control off to the GLUT event handler */
571 int printf (const char *format, ...) {
577 /* Revision 1.12 1997/08/27 21:32:24 curt
578 /* Restructured view calculation code. Added stars.
580 * Revision 1.11 1997/08/27 03:30:16 curt
581 * Changed naming scheme of basic shared structures.
583 * Revision 1.10 1997/08/25 20:27:22 curt
584 * Merged in initial HUD and Joystick code.
586 * Revision 1.9 1997/08/22 21:34:39 curt
587 * Doing a bit of reorganizing and house cleaning.
589 * Revision 1.8 1997/08/19 23:55:03 curt
590 * Worked on better simulating real lighting.
592 * Revision 1.7 1997/08/16 12:22:38 curt
593 * Working on improving the lighting/shading.
595 * Revision 1.6 1997/08/13 20:24:56 curt
596 * Changes due to changing sunpos interface.
598 * Revision 1.5 1997/08/06 21:08:32 curt
599 * Sun position now *really* works (I think) ... I still have sun time warping
600 * code in place, probably should remove it soon.
602 * Revision 1.4 1997/08/06 15:41:26 curt
603 * Working on correct sun position.
605 * Revision 1.3 1997/08/06 00:24:22 curt
606 * Working on correct real time sun lighting.
608 * Revision 1.2 1997/08/04 20:25:15 curt
609 * Organizational tweaking.
611 * Revision 1.1 1997/08/02 18:45:00 curt
612 * Renamed GLmain.c GLUTmain.c
614 * Revision 1.43 1997/08/02 16:23:47 curt
617 * Revision 1.42 1997/08/01 19:43:33 curt
618 * Making progress with coordinate system overhaul.
620 * Revision 1.41 1997/07/31 22:52:37 curt
621 * Working on redoing internal coordinate systems & scenery transformations.
623 * Revision 1.40 1997/07/30 16:12:42 curt
624 * Moved fg_random routines from Util/ to Math/
626 * Revision 1.39 1997/07/21 14:45:01 curt
629 * Revision 1.38 1997/07/19 23:04:47 curt
630 * Added an initial weather section.
632 * Revision 1.37 1997/07/19 22:34:02 curt
633 * Moved PI definitions to ../constants.h
634 * Moved random() stuff to ../Utils/ and renamed fg_random()
636 * Revision 1.36 1997/07/18 23:41:25 curt
637 * Tweaks for building with Cygnus Win32 compiler.
639 * Revision 1.35 1997/07/18 14:28:34 curt
640 * Hacked in some support for wind/turbulence.
642 * Revision 1.34 1997/07/16 20:04:48 curt
643 * Minor tweaks to aid Win32 port.
645 * Revision 1.33 1997/07/12 03:50:20 curt
646 * Added an #include <Windows32/Base.h> to help compiling for Win32
648 * Revision 1.32 1997/07/11 03:23:18 curt
649 * Solved some scenery display/orientation problems. Still have a positioning
650 * (or transformation?) problem.
652 * Revision 1.31 1997/07/11 01:29:58 curt
653 * More tweaking of terrian floor.
655 * Revision 1.30 1997/07/10 04:26:37 curt
656 * We now can interpolated ground elevation for any position in the grid. We
657 * can use this to enforce a "hard" ground. We still need to enforce some
658 * bounds checking so that we don't try to lookup data points outside the
661 * Revision 1.29 1997/07/09 21:31:12 curt
662 * Working on making the ground "hard."
664 * Revision 1.28 1997/07/08 18:20:12 curt
665 * Working on establishing a hard ground.
667 * Revision 1.27 1997/07/07 20:59:49 curt
668 * Working on scenery transformations to enable us to fly fluidly over the
669 * poles with no discontinuity/distortion in scenery.
671 * Revision 1.26 1997/07/05 20:43:34 curt
672 * renamed mat3 directory to Math so we could add other math related routines.
674 * Revision 1.25 1997/06/29 21:19:17 curt
675 * Working on scenery management system.
677 * Revision 1.24 1997/06/26 22:14:53 curt
678 * Beginning work on a scenery management system.
680 * Revision 1.23 1997/06/26 19:08:33 curt
681 * Restructuring make, adding automatic "make dep" support.
683 * Revision 1.22 1997/06/25 15:39:47 curt
684 * Minor changes to compile with rsxnt/win32.
686 * Revision 1.21 1997/06/22 21:44:41 curt
687 * Working on intergrating the VRML (subset) parser.
689 * Revision 1.20 1997/06/21 17:12:53 curt
690 * Capitalized subdirectory names.
692 * Revision 1.19 1997/06/18 04:10:31 curt
693 * A couple more runway tweaks ...
695 * Revision 1.18 1997/06/18 02:21:24 curt
698 * Revision 1.17 1997/06/17 16:51:58 curt
699 * Timer interval stuff now uses gettimeofday() instead of ftime()
701 * Revision 1.16 1997/06/17 04:19:16 curt
702 * More timer related tweaks with respect to view direction changes.
704 * Revision 1.15 1997/06/17 03:41:10 curt
705 * Nonsignal based interval timing is now working.
706 * This would be a good time to look at cleaning up the code structure a bit.
708 * Revision 1.14 1997/06/16 19:32:51 curt
709 * Starting to add general timer support.
711 * Revision 1.13 1997/06/02 03:40:06 curt
712 * A tiny bit more view tweaking.
714 * Revision 1.12 1997/06/02 03:01:38 curt
715 * Working on views (side, front, back, transitions, etc.)
717 * Revision 1.11 1997/05/31 19:16:25 curt
718 * Elevator trim added.
720 * Revision 1.10 1997/05/31 04:13:52 curt
723 * Continuing work on the LaRCsim flight model integration.
724 * Added some MSFS-like keyboard input handling.
726 * Revision 1.9 1997/05/30 19:27:01 curt
727 * The LaRCsim flight model is starting to look like it is working.
729 * Revision 1.8 1997/05/30 03:54:10 curt
730 * Made a bit more progress towards integrating the LaRCsim flight model.
732 * Revision 1.7 1997/05/29 22:39:49 curt
733 * Working on incorporating the LaRCsim flight model.
735 * Revision 1.6 1997/05/29 12:31:39 curt
736 * Minor tweaks, moving towards general flight model integration.
738 * Revision 1.5 1997/05/29 02:33:23 curt
739 * Updated to reflect changing interfaces in other "modules."
741 * Revision 1.4 1997/05/27 17:44:31 curt
742 * Renamed & rearranged variables and routines. Added some initial simple
743 * timer/alarm routines so the flight model can be updated on a regular
746 * Revision 1.3 1997/05/23 15:40:25 curt
747 * Added GNU copyright headers.
750 * Revision 1.2 1997/05/23 00:35:12 curt
751 * Trying to get fog to work ...
753 * Revision 1.1 1997/05/21 15:57:51 curt
754 * Renamed due to added GLUT support.
756 * Revision 1.3 1997/05/19 18:22:42 curt
757 * Parameter tweaking ... starting to stub in fog support.
759 * Revision 1.2 1997/05/17 00:17:34 curt
760 * Trying to stub in support for standard OpenGL.
762 * Revision 1.1 1997/05/16 16:05:52 curt