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 **************************************************************************/
42 #include "../constants.h"
43 #include "../general.h"
44 #include "../Aircraft/aircraft.h"
45 #include "../Main/views.h"
46 #include "../Time/fg_time.h"
49 #define EpochStart (631065600)
50 #define DaysSinceEpoch(secs) (((secs)-EpochStart)*(1.0/(24*3600)))
53 /* Define four structures, each with varying amounts of stars */
54 /* static */ GLint stars[FG_STAR_LEVELS];
57 /* Initialize the Star Management Subsystem */
61 struct CelestialCoord pltPos;
63 char line[256], name[256];
65 double right_ascension, declination, magnitude;
66 double ra_save, decl_save;
67 double ra_save1, decl_save1;
68 int count, i, j, max_stars;
72 /* build the full path name to the stars data base file */
74 strcat(path, g->root_dir);
75 strcat(path, "/Scenery/");
76 strcat(path, "Stars.dat");
78 max_stars = FG_MAX_STARS;
80 for ( i = 0; i < FG_STAR_LEVELS; i++ ) {
81 printf("Loading %d Stars: %s\n", max_stars, path);
83 if ( (fd = fopen(path, "r")) == NULL ) {
84 printf("Cannot open star file: '%s'\n", path);
88 stars[i] = glGenLists(1);
89 glNewList( stars[i], GL_COMPILE );
92 /* read in each line of the file */
94 while ( (fgets(line, 256, fd) != NULL) && (count < max_stars) ) {
97 /* printf("Read line = %s", front); */
99 /* advance to first non-whitespace character */
100 while ( (front[0] == ' ') || (front[0] == '\t') ) {
104 /* printf("Line length (after trimming) = %d\n", strlen(front)); */
106 if ( front[0] == '#' ) {
108 } else if ( strlen(front) <= 1 ) {
115 while ( end[0] != ',' ) {
123 sscanf(front, "%lf,%lf,%lf\n",
124 &right_ascension, &declination, &magnitude);
127 if ( strcmp(name, "Betelgeuse") == 0 ) {
128 printf(" *** Marking %s\n", name);
129 ra_save = right_ascension;
130 decl_save = declination;
135 if ( strcmp(name, "Alnilam") == 0 ) {
136 printf(" *** Marking %s\n", name);
137 ra_save1 = right_ascension;
138 decl_save1 = declination;
142 /* scale magnitudes to (0.0 - 1.0) */
143 magnitude = (0.0 - magnitude) / 5.0 + 1.0;
145 /* scale magnitudes again so they look ok */
146 if ( magnitude > 1.0 ) { magnitude = 1.0; }
147 if ( magnitude < 0.0 ) { magnitude = 0.0; }
149 magnitude * 0.7 + (((FG_STAR_LEVELS - 1) - i) * 0.1);
150 /* printf("Found star: %d %s, %.3f %.3f %.3f\n", count,
151 name, right_ascension, declination, magnitude); */
153 glColor3f( magnitude, magnitude, magnitude );
154 /*glColor3f(0,0,0);*/
155 glVertex3f( 190000.0 * cos(right_ascension) * cos(declination),
156 190000.0 * sin(right_ascension) * cos(declination),
157 190000.0 * sin(declination) );
160 } /* if valid line */
166 /* Add the planets to all four display lists */
167 for ( j = 2; j < 9; j++ ) {
168 pltPos = fgCalculatePlanet(pltOrbElements[j],
169 pltOrbElements[0], cur_time_params);
170 printf("Planet found at %f (ra), %f (dec)\n",
171 pltPos.RightAscension, pltPos.Declination);
172 /* give the planets a temporary color, for testing purposes */
173 glColor3f( 1.0, 0.0, 0.0);
174 glVertex3f( 190000.0 * cos(pltPos.RightAscension) *
175 cos(pltPos.Declination),
176 190000.0 * sin(pltPos.RightAscension) *
177 cos(pltPos.Declination),
178 190000.0 * sin(pltPos.Declination) );
183 glBegin(GL_LINE_LOOP);
184 glColor3f(1.0, 0.0, 0.0);
185 glVertex3f( 190000.0 * cos(ra_save-0.2) * cos(decl_save-0.2),
186 190000.0 * sin(ra_save-0.2) * cos(decl_save-0.2),
187 190000.0 * sin(decl_save-0.2) );
188 glVertex3f( 190000.0 * cos(ra_save+0.2) * cos(decl_save-0.2),
189 190000.0 * sin(ra_save+0.2) * cos(decl_save-0.2),
190 190000.0 * sin(decl_save-0.2) );
191 glVertex3f( 190000.0 * cos(ra_save+0.2) * cos(decl_save+0.2),
192 190000.0 * sin(ra_save+0.2) * cos(decl_save+0.2),
193 190000.0 * sin(decl_save+0.2) );
194 glVertex3f( 190000.0 * cos(ra_save-0.2) * cos(decl_save+0.2),
195 190000.0 * sin(ra_save-0.2) * cos(decl_save+0.2),
196 190000.0 * sin(decl_save+0.2) );
201 glBegin(GL_LINE_LOOP);
202 glColor3f(0.0, 1.0, 0.0);
203 glVertex3f( 190000.0 * cos(ra_save1-0.2) * cos(decl_save1-0.2),
204 190000.0 * sin(ra_save1-0.2) * cos(decl_save1-0.2),
205 190000.0 * sin(decl_save1-0.2) );
206 glVertex3f( 190000.0 * cos(ra_save1+0.2) * cos(decl_save1-0.2),
207 190000.0 * sin(ra_save1+0.2) * cos(decl_save1-0.2),
208 190000.0 * sin(decl_save1-0.2) );
209 glVertex3f( 190000.0 * cos(ra_save1+0.2) * cos(decl_save1+0.2),
210 190000.0 * sin(ra_save1+0.2) * cos(decl_save1+0.2),
211 190000.0 * sin(decl_save1+0.2) );
212 glVertex3f( 190000.0 * cos(ra_save1-0.2) * cos(decl_save1+0.2),
213 190000.0 * sin(ra_save1-0.2) * cos(decl_save1+0.2),
214 190000.0 * sin(decl_save1+0.2) );
226 void fgStarsRender() {
233 f = ¤t_aircraft.flight;
234 l = &cur_light_params;
235 t = &cur_time_params;
238 /* FG_PI_2 + 0.1 is about 6 degrees after sundown and before sunrise */
240 /* t->sun_angle = 3.0; */ /* to force stars to be drawn (for testing) */
242 /* render the stars */
243 if ( l->sun_angle > (FG_PI_2 + 5 * DEG_TO_RAD ) ) {
244 /* determine which star structure to draw */
245 if ( l->sun_angle > (FG_PI_2 + 7.25 * DEG_TO_RAD ) ) {
247 } else if ( l->sun_angle > (FG_PI_2 + 6.50 * DEG_TO_RAD ) ) {
249 } else if ( l->sun_angle > (FG_PI_2 + 5.75 * DEG_TO_RAD ) ) {
255 printf("RENDERING STARS = %d (night)\n", i);
257 glDisable( GL_LIGHTING );
258 glCallList(stars[i]);
259 glEnable( GL_LIGHTING );
261 printf("not RENDERING STARS (day)\n");
267 /* Revision 1.19 1997/12/12 19:53:00 curt
268 /* Working on lightling and material properties.
270 * Revision 1.18 1997/12/10 22:37:52 curt
271 * Prepended "fg" on the name of all global structures that didn't have it yet.
272 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
274 * Revision 1.17 1997/12/09 04:25:33 curt
275 * Working on adding a global lighting params structure.
277 * Revision 1.16 1997/11/25 19:25:38 curt
278 * Changes to integrate Durk's moon/sun code updates + clean up.
280 * Revision 1.15 1997/10/30 12:38:45 curt
281 * Working on new scenery subsystem.
283 * Revision 1.14 1997/10/28 21:00:22 curt
284 * Changing to new terrain format.
286 * Revision 1.13 1997/10/25 03:18:28 curt
287 * Incorporated sun, moon, and planet position and rendering code contributed
290 * Revision 1.12 1997/09/23 00:29:43 curt
291 * Tweaks to get things to compile with gcc-win32.
293 * Revision 1.11 1997/09/22 14:44:21 curt
294 * Continuing to try to align stars correctly.
296 * Revision 1.10 1997/09/20 03:34:32 curt
297 * Still trying to get those durned stars aligned properly.
299 * Revision 1.9 1997/09/18 16:20:09 curt
300 * At dusk/dawn add/remove stars in stages.
302 * Revision 1.8 1997/09/16 22:14:52 curt
303 * Tweaked time of day lighting equations. Don't draw stars during the day.
305 * Revision 1.7 1997/09/16 15:50:31 curt
306 * Working on star alignment and time issues.
308 * Revision 1.6 1997/09/05 14:17:31 curt
309 * More tweaking with stars.
311 * Revision 1.5 1997/09/05 01:35:59 curt
312 * Working on getting stars right.
314 * Revision 1.4 1997/09/04 02:17:38 curt
317 * Revision 1.3 1997/08/29 17:55:28 curt
318 * Worked on properly aligning the stars.
320 * Revision 1.2 1997/08/27 21:32:30 curt
321 * Restructured view calculation code. Added stars.
323 * Revision 1.1 1997/08/27 03:34:48 curt