1 /**************************************************************************
2 * stars.c -- data structures and routines for managing and rendering stars.
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.
23 * (Log is kept at end of this file)
24 **************************************************************************/
37 #include "../XGL/xgl.h"
43 #include "../Include/constants.h"
44 #include "../Include/general.h"
45 #include "../Aircraft/aircraft.h"
46 #include "../Main/views.h"
47 #include "../Time/fg_time.h"
50 #define EpochStart (631065600)
51 #define DaysSinceEpoch(secs) (((secs)-EpochStart)*(1.0/(24*3600)))
54 /* Define four structures, each with varying amounts of stars */
55 /* static */ GLint stars[FG_STAR_LEVELS];
58 /* Initialize the Star Management Subsystem */
62 struct CelestialCoord pltPos;
64 char line[256], name[256];
66 double right_ascension, declination, magnitude;
67 double ra_save, decl_save;
68 double ra_save1, decl_save1;
69 int count, i, j, max_stars;
73 /* build the full path name to the stars data base file */
75 strcat(path, g->root_dir);
76 strcat(path, "/Scenery/");
77 strcat(path, "Stars.dat");
79 max_stars = FG_MAX_STARS;
81 for ( i = 0; i < FG_STAR_LEVELS; i++ ) {
82 printf("Loading %d Stars: %s\n", max_stars, path);
84 if ( (fd = fopen(path, "r")) == NULL ) {
85 printf("Cannot open star file: '%s'\n", path);
89 stars[i] = xglGenLists(1);
90 xglNewList( stars[i], GL_COMPILE );
91 xglBegin( GL_POINTS );
93 /* read in each line of the file */
95 while ( (fgets(line, 256, fd) != NULL) && (count < max_stars) ) {
98 /* printf("Read line = %s", front); */
100 /* advance to first non-whitespace character */
101 while ( (front[0] == ' ') || (front[0] == '\t') ) {
105 /* printf("Line length (after trimming) = %d\n", strlen(front)); */
107 if ( front[0] == '#' ) {
109 } else if ( strlen(front) <= 1 ) {
116 while ( end[0] != ',' ) {
124 sscanf(front, "%lf,%lf,%lf\n",
125 &right_ascension, &declination, &magnitude);
128 if ( strcmp(name, "Betelgeuse") == 0 ) {
129 printf(" *** Marking %s\n", name);
130 ra_save = right_ascension;
131 decl_save = declination;
136 if ( strcmp(name, "Alnilam") == 0 ) {
137 printf(" *** Marking %s\n", name);
138 ra_save1 = right_ascension;
139 decl_save1 = declination;
143 /* scale magnitudes to (0.0 - 1.0) */
144 magnitude = (0.0 - magnitude) / 5.0 + 1.0;
146 /* scale magnitudes again so they look ok */
147 if ( magnitude > 1.0 ) { magnitude = 1.0; }
148 if ( magnitude < 0.0 ) { magnitude = 0.0; }
150 magnitude * 0.7 + (((FG_STAR_LEVELS - 1) - i) * 0.1);
151 /* printf("Found star: %d %s, %.3f %.3f %.3f\n", count,
152 name, right_ascension, declination, magnitude); */
154 xglColor3f( magnitude, magnitude, magnitude );
155 /*xglColor3f(0,0,0);*/
156 xglVertex3f( 190000.0 * cos(right_ascension) * cos(declination),
157 190000.0 * sin(right_ascension) * cos(declination),
158 190000.0 * sin(declination) );
161 } /* if valid line */
167 /* Add the planets to all four display lists */
168 for ( j = 2; j < 9; j++ ) {
169 pltPos = fgCalculatePlanet(pltOrbElements[j],
170 pltOrbElements[0], cur_time_params);
171 printf("Planet found at %f (ra), %f (dec)\n",
172 pltPos.RightAscension, pltPos.Declination);
173 /* give the planets a temporary color, for testing purposes */
174 xglColor3f( 1.0, 0.0, 0.0);
175 xglVertex3f( 190000.0 * cos(pltPos.RightAscension) *
176 cos(pltPos.Declination),
177 190000.0 * sin(pltPos.RightAscension) *
178 cos(pltPos.Declination),
179 190000.0 * sin(pltPos.Declination) );
184 xglBegin(GL_LINE_LOOP);
185 xglColor3f(1.0, 0.0, 0.0);
186 xglVertex3f( 190000.0 * cos(ra_save-0.2) * cos(decl_save-0.2),
187 190000.0 * sin(ra_save-0.2) * cos(decl_save-0.2),
188 190000.0 * sin(decl_save-0.2) );
189 xglVertex3f( 190000.0 * cos(ra_save+0.2) * cos(decl_save-0.2),
190 190000.0 * sin(ra_save+0.2) * cos(decl_save-0.2),
191 190000.0 * sin(decl_save-0.2) );
192 xglVertex3f( 190000.0 * cos(ra_save+0.2) * cos(decl_save+0.2),
193 190000.0 * sin(ra_save+0.2) * cos(decl_save+0.2),
194 190000.0 * sin(decl_save+0.2) );
195 xglVertex3f( 190000.0 * cos(ra_save-0.2) * cos(decl_save+0.2),
196 190000.0 * sin(ra_save-0.2) * cos(decl_save+0.2),
197 190000.0 * sin(decl_save+0.2) );
202 xglBegin(GL_LINE_LOOP);
203 xglColor3f(0.0, 1.0, 0.0);
204 xglVertex3f( 190000.0 * cos(ra_save1-0.2) * cos(decl_save1-0.2),
205 190000.0 * sin(ra_save1-0.2) * cos(decl_save1-0.2),
206 190000.0 * sin(decl_save1-0.2) );
207 xglVertex3f( 190000.0 * cos(ra_save1+0.2) * cos(decl_save1-0.2),
208 190000.0 * sin(ra_save1+0.2) * cos(decl_save1-0.2),
209 190000.0 * sin(decl_save1-0.2) );
210 xglVertex3f( 190000.0 * cos(ra_save1+0.2) * cos(decl_save1+0.2),
211 190000.0 * sin(ra_save1+0.2) * cos(decl_save1+0.2),
212 190000.0 * sin(decl_save1+0.2) );
213 xglVertex3f( 190000.0 * cos(ra_save1-0.2) * cos(decl_save1+0.2),
214 190000.0 * sin(ra_save1-0.2) * cos(decl_save1+0.2),
215 190000.0 * sin(decl_save1+0.2) );
227 void fgStarsRender() {
234 f = ¤t_aircraft.flight;
235 l = &cur_light_params;
236 t = &cur_time_params;
239 /* FG_PI_2 + 0.1 is about 6 degrees after sundown and before sunrise */
241 /* t->sun_angle = 3.0; */ /* to force stars to be drawn (for testing) */
243 /* render the stars */
244 if ( l->sun_angle > (FG_PI_2 + 5 * DEG_TO_RAD ) ) {
245 /* determine which star structure to draw */
246 if ( l->sun_angle > (FG_PI_2 + 7.25 * DEG_TO_RAD ) ) {
248 } else if ( l->sun_angle > (FG_PI_2 + 6.50 * DEG_TO_RAD ) ) {
250 } else if ( l->sun_angle > (FG_PI_2 + 5.75 * DEG_TO_RAD ) ) {
256 printf("RENDERING STARS = %d (night)\n", i);
258 xglDisable( GL_LIGHTING );
259 xglCallList(stars[i]);
260 xglEnable( GL_LIGHTING );
262 printf("not RENDERING STARS (day)\n");
268 /* Revision 1.20 1997/12/15 23:55:03 curt
269 /* Add xgl wrappers for debugging.
270 /* Generate terrain normals on the fly.
272 * Revision 1.19 1997/12/12 19:53:00 curt
273 * Working on lightling and material properties.
275 * Revision 1.18 1997/12/10 22:37:52 curt
276 * Prepended "fg" on the name of all global structures that didn't have it yet.
277 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
279 * Revision 1.17 1997/12/09 04:25:33 curt
280 * Working on adding a global lighting params structure.
282 * Revision 1.16 1997/11/25 19:25:38 curt
283 * Changes to integrate Durk's moon/sun code updates + clean up.
285 * Revision 1.15 1997/10/30 12:38:45 curt
286 * Working on new scenery subsystem.
288 * Revision 1.14 1997/10/28 21:00:22 curt
289 * Changing to new terrain format.
291 * Revision 1.13 1997/10/25 03:18:28 curt
292 * Incorporated sun, moon, and planet position and rendering code contributed
295 * Revision 1.12 1997/09/23 00:29:43 curt
296 * Tweaks to get things to compile with gcc-win32.
298 * Revision 1.11 1997/09/22 14:44:21 curt
299 * Continuing to try to align stars correctly.
301 * Revision 1.10 1997/09/20 03:34:32 curt
302 * Still trying to get those durned stars aligned properly.
304 * Revision 1.9 1997/09/18 16:20:09 curt
305 * At dusk/dawn add/remove stars in stages.
307 * Revision 1.8 1997/09/16 22:14:52 curt
308 * Tweaked time of day lighting equations. Don't draw stars during the day.
310 * Revision 1.7 1997/09/16 15:50:31 curt
311 * Working on star alignment and time issues.
313 * Revision 1.6 1997/09/05 14:17:31 curt
314 * More tweaking with stars.
316 * Revision 1.5 1997/09/05 01:35:59 curt
317 * Working on getting stars right.
319 * Revision 1.4 1997/09/04 02:17:38 curt
322 * Revision 1.3 1997/08/29 17:55:28 curt
323 * Worked on properly aligning the stars.
325 * Revision 1.2 1997/08/27 21:32:30 curt
326 * Restructured view calculation code. Added stars.
328 * Revision 1.1 1997/08/27 03:34:48 curt