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 **************************************************************************/
44 #include <Aircraft/aircraft.h>
45 #include <Debug/fg_debug.h>
46 #include <Include/fg_constants.h>
47 #include <Include/fg_types.h>
48 #include <Include/fg_zlib.h>
49 #include <Main/options.hxx>
50 #include <Main/views.hxx>
51 #include <Time/fg_time.hxx>
54 #include "planets.hxx"
58 #define EpochStart (631065600)
59 #define DaysSinceEpoch(secs) (((secs)-EpochStart)*(1.0/(24*3600)))
60 #define FG_MAX_STARS 3500
62 /* Define four structures, each with varying amounts of stars */
63 static GLint stars[FG_STAR_LEVELS];
66 /* Initialize the Star Management Subsystem */
67 int fgStarsInit( void ) {
68 fgPoint3d starlist[FG_MAX_STARS];
70 /* struct CelestialCoord pltPos; */
72 char line[256], name[256];
74 double right_ascension, declination, magnitude;
75 double min_magnitude[FG_STAR_LEVELS];
76 /* double ra_save, decl_save; */
77 /* double ra_save1, decl_save1; */
78 int i, j, starcount, count;
80 fgPrintf( FG_ASTRO, FG_INFO, "Initializing stars\n");
82 /* build the full path name to the stars data base file */
83 path = current_options.get_fg_root() + "/Astro/stars";
84 gzpath = path + ".gz";
86 if ( FG_STAR_LEVELS < 4 ) {
87 fgPrintf( FG_ASTRO, FG_EXIT, "Big whups in stars.cxx\n");
90 fgPrintf( FG_ASTRO, FG_INFO, " Loading stars from %s\n", path.c_str() );
92 // load star data file
93 if ( (fd = fgopen(path.c_str(), "rb")) == NULL ) {
94 if ( (fd = fgopen(gzpath.c_str(), "rb")) == NULL ) {
95 // Oops, lets not even try to continue. This is critical.
96 fgPrintf( FG_ASTRO, FG_EXIT,
97 "Cannot open star file: '%s'\n", path.c_str() );
103 // read in each line of the file
104 while ( (fggets(fd, line, 256) != NULL) && (starcount < FG_MAX_STARS) ) {
107 // printf(" Read line = %s", front);
109 // advance to first non-whitespace character
110 while ( (front[0] == ' ') || (front[0] == '\t') ) {
114 // printf(" Line length (after trimming) = %d\n", strlen(front));
116 if ( front[0] == '#' ) {
118 } else if ( strlen(front) <= 1 ) {
125 while ( end[0] != ',' ) {
133 sscanf(front, "%lf,%lf,%lf\n",
134 &right_ascension, &declination, &magnitude);
135 starlist[starcount].x = right_ascension;
136 starlist[starcount].y = declination;
137 starlist[starcount].z = magnitude;
142 min_magnitude[0] = 4.2;
143 min_magnitude[1] = 3.6;
144 min_magnitude[2] = 3.0;
145 min_magnitude[3] = 2.4;
146 min_magnitude[4] = 1.8;
147 min_magnitude[5] = 1.2;
148 min_magnitude[6] = 0.6;
149 min_magnitude[7] = 0.0;
151 // build the various star display lists
152 for ( i = 0; i < FG_STAR_LEVELS; i++ ) {
154 stars[i] = xglGenLists(1);
155 xglNewList( stars[i], GL_COMPILE );
156 xglBegin( GL_POINTS );
160 for ( j = 0; j < starcount; j++ ) {
161 magnitude = starlist[j].z;
162 // printf("magnitude = %.2f\n", magnitude);
164 if ( magnitude < min_magnitude[i] ) {
165 right_ascension = starlist[j].x;
166 declination = starlist[j].y;
170 /* scale magnitudes to (0.0 - 1.0) */
171 magnitude = (0.0 - magnitude) / 5.0 + 1.0;
173 /* scale magnitudes again so they look ok */
174 if ( magnitude > 1.0 ) { magnitude = 1.0; }
175 if ( magnitude < 0.0 ) { magnitude = 0.0; }
177 magnitude * 0.7 + (((FG_STAR_LEVELS - 1) - i) * 0.042);
179 magnitude = magnitude * 0.9 +
180 (((FG_STAR_LEVELS - 1) - i) * 0.014);
181 /* printf(" Found star: %d %s, %.3f %.3f %.3f\n", count,
182 name, right_ascension, declination, magnitude); */
184 xglColor3f( magnitude, magnitude, magnitude );
185 /*xglColor3f(0,0,0);*/
186 xglVertex3f( 50000.0*cos(right_ascension)*cos(declination),
187 50000.0*sin(right_ascension)*cos(declination),
188 50000.0*sin(declination) );
195 xglBegin(GL_LINE_LOOP);
196 xglColor3f(1.0, 0.0, 0.0);
197 xglVertex3f( 50000.0 * cos(ra_save-0.2) * cos(decl_save-0.2),
198 50000.0 * sin(ra_save-0.2) * cos(decl_save-0.2),
199 50000.0 * sin(decl_save-0.2) );
200 xglVertex3f( 50000.0 * cos(ra_save+0.2) * cos(decl_save-0.2),
201 50000.0 * sin(ra_save+0.2) * cos(decl_save-0.2),
202 50000.0 * sin(decl_save-0.2) );
203 xglVertex3f( 50000.0 * cos(ra_save+0.2) * cos(decl_save+0.2),
204 50000.0 * sin(ra_save+0.2) * cos(decl_save+0.2),
205 50000.0 * sin(decl_save+0.2) );
206 xglVertex3f( 50000.0 * cos(ra_save-0.2) * cos(decl_save+0.2),
207 50000.0 * sin(ra_save-0.2) * cos(decl_save+0.2),
208 50000.0 * sin(decl_save+0.2) );
213 xglBegin(GL_LINE_LOOP);
214 xglColor3f(0.0, 1.0, 0.0);
215 xglVertex3f( 50000.0 * cos(ra_save1-0.2) * cos(decl_save1-0.2),
216 50000.0 * sin(ra_save1-0.2) * cos(decl_save1-0.2),
217 50000.0 * sin(decl_save1-0.2) );
218 xglVertex3f( 50000.0 * cos(ra_save1+0.2) * cos(decl_save1-0.2),
219 50000.0 * sin(ra_save1+0.2) * cos(decl_save1-0.2),
220 50000.0 * sin(decl_save1-0.2) );
221 xglVertex3f( 50000.0 * cos(ra_save1+0.2) * cos(decl_save1+0.2),
222 50000.0 * sin(ra_save1+0.2) * cos(decl_save1+0.2),
223 50000.0 * sin(decl_save1+0.2) );
224 xglVertex3f( 50000.0 * cos(ra_save1-0.2) * cos(decl_save1+0.2),
225 50000.0 * sin(ra_save1-0.2) * cos(decl_save1+0.2),
226 50000.0 * sin(decl_save1+0.2) );
232 fgPrintf( FG_ASTRO, FG_INFO,
233 " Loading %d stars brighter than %.2f\n",
234 count, min_magnitude[i]);
237 return 1; // OK, we got here because initialization worked.
242 void fgStarsRender( void ) {
249 f = current_aircraft.flight;
250 l = &cur_light_params;
251 t = &cur_time_params;
254 /* FG_PI_2 + 0.1 is about 6 degrees after sundown and before sunrise */
256 /* t->sun_angle = 3.0; */ /* to force stars to be drawn (for testing) */
258 /* render the stars */
259 if ( l->sun_angle > (FG_PI_2 + 5 * DEG_TO_RAD ) ) {
260 /* determine which star structure to draw */
261 if ( l->sun_angle > (FG_PI_2 + 10.0 * DEG_TO_RAD ) ) {
263 } else if ( l->sun_angle > (FG_PI_2 + 8.8 * DEG_TO_RAD ) ) {
265 } else if ( l->sun_angle > (FG_PI_2 + 7.5 * DEG_TO_RAD ) ) {
267 } else if ( l->sun_angle > (FG_PI_2 + 7.0 * DEG_TO_RAD ) ) {
269 } else if ( l->sun_angle > (FG_PI_2 + 6.5 * DEG_TO_RAD ) ) {
271 } else if ( l->sun_angle > (FG_PI_2 + 6.0 * DEG_TO_RAD ) ) {
273 } else if ( l->sun_angle > (FG_PI_2 + 5.5 * DEG_TO_RAD ) ) {
279 /* printf("RENDERING STARS = %d (night)\n", i); */
281 xglCallList(stars[i]);
283 /* printf("not RENDERING STARS (day)\n"); */
289 /* Revision 1.12 1998/08/27 17:02:01 curt
290 /* Contributions from Bernie Bright <bbright@c031.aone.net.au>
291 /* - use strings for fg_root and airport_id and added methods to return
293 /* - inlined all access methods,
294 /* - made the parsing functions private methods,
295 /* - deleted some unused functions.
296 /* - propogated some of these changes out a bit further.
298 * Revision 1.11 1998/08/25 20:53:29 curt
299 * Shuffled $FG_ROOT file layout.
301 * Revision 1.10 1998/08/10 20:33:09 curt
302 * Rewrote star loading and rendering to:
303 * 1. significantly improve load speed
304 * 2. transition from no stars to stars through eight stages.
306 * Revision 1.9 1998/08/06 12:45:20 curt
307 * Modified to bring in stars in 8 increments based on magnitude, not number
310 * Revision 1.8 1998/07/13 21:00:10 curt
311 * Wrote access functions for current fgOPTIONS.
313 * Revision 1.7 1998/05/29 20:35:42 curt
314 * Added zlib support for reading in compressed data files.
316 * Revision 1.6 1998/05/13 18:25:35 curt
317 * Root path info moved to fgOPTIONS.
319 * Revision 1.5 1998/04/28 01:19:03 curt
320 * Type-ified fgTIME and fgVIEW
322 * Revision 1.4 1998/04/26 05:10:02 curt
323 * "struct fgLIGHT" -> "fgLIGHT" because fgLIGHT is typedef'd.
325 * Revision 1.3 1998/04/25 22:06:26 curt
326 * Edited cvs log messages in source files ... bad bad bad!
328 * Revision 1.2 1998/04/24 00:45:03 curt
329 * Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
330 * Fixed a bug when generating sky colors.
332 * Revision 1.1 1998/04/22 13:21:34 curt
333 * C++ - ifing the code a bit.
335 * Revision 1.11 1998/04/18 04:13:58 curt
336 * Moved fg_debug.c to it's own library.
338 * Revision 1.10 1998/04/03 21:52:51 curt
339 * Converting to Gnu autoconf system.
341 * Revision 1.9 1998/03/14 00:27:12 curt
342 * Updated fgGENERAL to a "type" of struct.
344 * Revision 1.8 1998/02/12 21:59:38 curt
345 * Incorporated code changes contributed by Charlie Hotchkiss
346 * <chotchkiss@namg.us.anritsu.com>
348 * Revision 1.7 1998/02/09 15:07:48 curt
351 * Revision 1.6 1998/02/02 20:53:23 curt
354 * Revision 1.5 1998/01/27 18:35:53 curt
357 * Revision 1.4 1998/01/27 00:47:49 curt
358 * Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
359 * system and commandline/config file processing code.
361 * Revision 1.3 1998/01/19 19:26:59 curt
362 * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
363 * This should simplify things tremendously.
365 * Revision 1.2 1998/01/19 18:40:18 curt
366 * Tons of little changes to clean up the code and to remove fatal errors
367 * when building with the c++ compiler.
369 * Revision 1.1 1998/01/07 03:16:20 curt
370 * Moved from .../Src/Scenery/ to .../Src/Astro/
372 * Revision 1.24 1997/12/30 22:22:39 curt
373 * Further integration of event manager.
375 * Revision 1.23 1997/12/30 20:47:53 curt
376 * Integrated new event manager with subsystem initializations.
378 * Revision 1.22 1997/12/30 16:36:53 curt
379 * Merged in Durk's changes ...
381 * Revision 1.21 1997/12/19 23:35:00 curt
382 * Lot's of tweaking with sky rendering and lighting.
384 * Revision 1.20 1997/12/15 23:55:03 curt
385 * Add xgl wrappers for debugging.
386 * Generate terrain normals on the fly.
388 * Revision 1.19 1997/12/12 19:53:00 curt
389 * Working on lightling and material properties.
391 * Revision 1.18 1997/12/10 22:37:52 curt
392 * Prepended "fg" on the name of all global structures that didn't have it yet.
393 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
395 * Revision 1.17 1997/12/09 04:25:33 curt
396 * Working on adding a global lighting params structure.
398 * Revision 1.16 1997/11/25 19:25:38 curt
399 * Changes to integrate Durk's moon/sun code updates + clean up.
401 * Revision 1.15 1997/10/30 12:38:45 curt
402 * Working on new scenery subsystem.
404 * Revision 1.14 1997/10/28 21:00:22 curt
405 * Changing to new terrain format.
407 * Revision 1.13 1997/10/25 03:18:28 curt
408 * Incorporated sun, moon, and planet position and rendering code contributed
411 * Revision 1.12 1997/09/23 00:29:43 curt
412 * Tweaks to get things to compile with gcc-win32.
414 * Revision 1.11 1997/09/22 14:44:21 curt
415 * Continuing to try to align stars correctly.
417 * Revision 1.10 1997/09/20 03:34:32 curt
418 * Still trying to get those durned stars aligned properly.
420 * Revision 1.9 1997/09/18 16:20:09 curt
421 * At dusk/dawn add/remove stars in stages.
423 * Revision 1.8 1997/09/16 22:14:52 curt
424 * Tweaked time of day lighting equations. Don't draw stars during the day.
426 * Revision 1.7 1997/09/16 15:50:31 curt
427 * Working on star alignment and time issues.
429 * Revision 1.6 1997/09/05 14:17:31 curt
430 * More tweaking with stars.
432 * Revision 1.5 1997/09/05 01:35:59 curt
433 * Working on getting stars right.
435 * Revision 1.4 1997/09/04 02:17:38 curt
438 * Revision 1.3 1997/08/29 17:55:28 curt
439 * Worked on properly aligning the stars.
441 * Revision 1.2 1997/08/27 21:32:30 curt
442 * Restructured view calculation code. Added stars.
444 * Revision 1.1 1997/08/27 03:34:48 curt