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);
126 if ( strcmp(name, "Betelgeuse") == 0 ) {
127 printf(" *** Marking %s\n", name);
128 ra_save = right_ascension;
129 decl_save = declination;
132 if ( strcmp(name, "Alnilam") == 0 ) {
133 printf(" *** Marking %s\n", name);
134 ra_save1 = right_ascension;
135 decl_save1 = declination;
138 /* scale magnitudes to (0.0 - 1.0) */
139 magnitude = (0.0 - magnitude) / 5.0 + 1.0;
141 /* scale magnitudes again so they look ok */
142 if ( magnitude > 1.0 ) { magnitude = 1.0; }
143 if ( magnitude < 0.0 ) { magnitude = 0.0; }
145 magnitude * 0.7 + (((FG_STAR_LEVELS - 1) - i) * 0.1);
146 /* printf("Found star: %d %s, %.3f %.3f %.3f\n", count,
147 name, right_ascension, declination, magnitude); */
149 glColor3f( magnitude, magnitude, magnitude );
150 /*glColor3f(0,0,0);*/
151 glVertex3f( 190000.0 * cos(right_ascension) * cos(declination),
152 190000.0 * sin(right_ascension) * cos(declination),
153 190000.0 * sin(declination) );
156 } /* if valid line */
162 /* Add the planets to all four display lists */
163 for ( j = 2; j < 9; j++ ) {
164 pltPos = fgCalculatePlanet(pltOrbElements[j],
165 pltOrbElements[0], cur_time_params);
166 printf("Planet found at %f (ra), %f (dec)\n",
167 pltPos.RightAscension, pltPos.Declination);
168 /* give the planets a temporary color, for testing purposes */
169 glColor3f( 1.0, 0.0, 0.0);
170 glVertex3f( 190000.0 * cos(pltPos.RightAscension) *
171 cos(pltPos.Declination),
172 190000.0 * sin(pltPos.RightAscension) *
173 cos(pltPos.Declination),
174 190000.0 * sin(pltPos.Declination) );
178 glBegin(GL_LINE_LOOP);
179 glColor3f(1.0, 0.0, 0.0);
180 glVertex3f( 190000.0 * cos(ra_save-0.2) * cos(decl_save-0.2),
181 190000.0 * sin(ra_save-0.2) * cos(decl_save-0.2),
182 190000.0 * sin(decl_save-0.2) );
183 glVertex3f( 190000.0 * cos(ra_save+0.2) * cos(decl_save-0.2),
184 190000.0 * sin(ra_save+0.2) * cos(decl_save-0.2),
185 190000.0 * sin(decl_save-0.2) );
186 glVertex3f( 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 glVertex3f( 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) );
194 glBegin(GL_LINE_LOOP);
195 glColor3f(0.0, 1.0, 0.0);
196 glVertex3f( 190000.0 * cos(ra_save1-0.2) * cos(decl_save1-0.2),
197 190000.0 * sin(ra_save1-0.2) * cos(decl_save1-0.2),
198 190000.0 * sin(decl_save1-0.2) );
199 glVertex3f( 190000.0 * cos(ra_save1+0.2) * cos(decl_save1-0.2),
200 190000.0 * sin(ra_save1+0.2) * cos(decl_save1-0.2),
201 190000.0 * sin(decl_save1-0.2) );
202 glVertex3f( 190000.0 * cos(ra_save1+0.2) * cos(decl_save1+0.2),
203 190000.0 * sin(ra_save1+0.2) * cos(decl_save1+0.2),
204 190000.0 * sin(decl_save1+0.2) );
205 glVertex3f( 190000.0 * cos(ra_save1-0.2) * cos(decl_save1+0.2),
206 190000.0 * sin(ra_save1-0.2) * cos(decl_save1+0.2),
207 190000.0 * sin(decl_save1+0.2) );
218 void fgStarsRender() {
223 static double warp = 0;
226 f = ¤t_aircraft.flight;
227 t = &cur_time_params;
230 /* FG_PI_2 + 0.1 is about 6 degrees after sundown and before sunrise */
232 /* t->sun_angle = 3.0; */ /* to force stars to be drawn (for testing) */
234 if ( t->sun_angle > (FG_PI_2 + 5 * DEG_TO_RAD ) ) {
235 /* determine which star structure to draw */
236 if ( t->sun_angle > (FG_PI_2 + 7.25 * DEG_TO_RAD ) ) {
238 } else if ( t->sun_angle > (FG_PI_2 + 6.50 * DEG_TO_RAD ) ) {
240 } else if ( t->sun_angle > (FG_PI_2 + 5.75 * DEG_TO_RAD ) ) {
246 printf("RENDERING STARS = %d (night)\n", i);
249 glDisable( GL_LIGHTING );
252 glTranslatef( v->view_pos.x, v->view_pos.y, v->view_pos.z );
254 angle = t->gst * 15.0; /* 15 degrees per hour rotation */
258 glRotatef( (angle+warp), 0.0, 0.0, -1.0 );
259 printf("Rotating stars by %.2f degrees + %.2f degrees\n",angle,warp);
261 glCallList(stars[i]);
264 glEnable( GL_LIGHTING );
267 printf("not RENDERING STARS (day)\n");
273 /* Revision 1.15 1997/10/30 12:38:45 curt
274 /* Working on new scenery subsystem.
276 * Revision 1.14 1997/10/28 21:00:22 curt
277 * Changing to new terrain format.
279 * Revision 1.13 1997/10/25 03:18:28 curt
280 * Incorporated sun, moon, and planet position and rendering code contributed
283 * Revision 1.12 1997/09/23 00:29:43 curt
284 * Tweaks to get things to compile with gcc-win32.
286 * Revision 1.11 1997/09/22 14:44:21 curt
287 * Continuing to try to align stars correctly.
289 * Revision 1.10 1997/09/20 03:34:32 curt
290 * Still trying to get those durned stars aligned properly.
292 * Revision 1.9 1997/09/18 16:20:09 curt
293 * At dusk/dawn add/remove stars in stages.
295 * Revision 1.8 1997/09/16 22:14:52 curt
296 * Tweaked time of day lighting equations. Don't draw stars during the day.
298 * Revision 1.7 1997/09/16 15:50:31 curt
299 * Working on star alignment and time issues.
301 * Revision 1.6 1997/09/05 14:17:31 curt
302 * More tweaking with stars.
304 * Revision 1.5 1997/09/05 01:35:59 curt
305 * Working on getting stars right.
307 * Revision 1.4 1997/09/04 02:17:38 curt
310 * Revision 1.3 1997/08/29 17:55:28 curt
311 * Worked on properly aligning the stars.
313 * Revision 1.2 1997/08/27 21:32:30 curt
314 * Restructured view calculation code. Added stars.
316 * Revision 1.1 1997/08/27 03:34:48 curt