1 // options.cxx -- class to handle command line options
3 // Written by Curtis Olson, started April 1998.
5 // Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 // (Log is kept at end of this file)
29 #include <Include/compiler.h>
31 #include <math.h> // rint()
33 #include <stdlib.h> // atof(), atoi()
38 #include <Debug/logstream.hxx>
39 #include <Misc/fgstream.hxx>
40 #include <FDM/flight.hxx>
41 #include <Include/fg_constants.h>
42 #include <Main/options.hxx>
44 #include "fg_serial.hxx"
47 FG_USING_NAMESPACE(std);
51 atof( const string& str )
53 return ::atof( str.c_str() );
57 atoi( const string& str )
59 return ::atoi( str.c_str() );
62 // Defined the shared options class here
63 fgOPTIONS current_options;
67 fgOPTIONS::fgOPTIONS() :
68 // starting longitude in degrees (west = -)
69 // starting latitude in degrees (south = -)
71 // Default initial position is Globe, AZ (P13)
75 // North of the city of Globe
79 // North of the city of Globe
83 // Near where I used to live in Globe, AZ
87 // 10125 Jewell St. NE
91 // Near KHSP (Hot Springs, VA)
92 // lon(-79.8338964 + 0.01),
93 // lat( 37.9514564 + 0.008),
95 // (SEZ) SEDONA airport
96 // lon(-111.7884614 + 0.01),
97 // lat( 34.8486289 - 0.015),
99 // Jim Brennon's Kingmont Observatory
100 // lon(-121.1131667),
103 // Huaras, Peru (S09d 31.871' W077d 31.498')
107 // Eclipse Watching w73.5 n10 (approx) 18:00 UT
112 // lon(-90.1953055556),
113 // lat( 45.4511388889),
115 // starting altitude in meters (this will be reset to ground level
116 // if it is lower than the terrain
119 // Initial Orientation
120 heading(270.0), // heading (yaw) angle in degress (Psi)
121 roll(0.0), // roll angle in degrees (Phi)
122 pitch(0.424), // pitch angle in degrees (Theta)
136 // Flight Model options
137 flight_model(FGInterface::FG_LARCSIM),
140 fog(FG_FOG_NICEST), // nicest
154 units(FG_UNITS_FEET),
161 // set initial values/defaults
162 char* envp = ::getenv( "FG_ROOT" );
164 if ( envp != NULL ) {
165 // fg_root could be anywhere, so default to environmental
166 // variable $FG_ROOT if it is set.
169 // Otherwise, default to a random compiled in location if
170 // $FG_ROOT is not set. This can still be overridden from the
171 // command line or a config file.
174 fg_root = "\\FlightGear";
176 fg_root = "/usr/local/lib/FlightGear";
180 airport_id = ""; // default airport id
182 // initialize port config string list
183 port_options_list.erase ( port_options_list.begin(),
184 port_options_list.end() );
189 fgOPTIONS::parse_time(const string& time_in) {
190 char *time_str, num[256];
191 double hours, minutes, seconds;
196 time_str = (char *)time_in.c_str();
198 // printf("parse_time(): %s\n", time_str);
201 if ( strlen(time_str) ) {
202 if ( time_str[0] == '+' ) {
205 } else if ( time_str[0] == '-' ) {
210 // printf("sign = %d\n", sign);
213 if ( strlen(time_str) ) {
215 while ( (time_str[0] != ':') && (time_str[0] != '\0') ) {
216 num[i] = time_str[0];
220 if ( time_str[0] == ':' ) {
225 // printf("hours = %.2lf\n", hours);
231 if ( strlen(time_str) ) {
233 while ( (time_str[0] != ':') && (time_str[0] != '\0') ) {
234 num[i] = time_str[0];
238 if ( time_str[0] == ':' ) {
243 // printf("minutes = %.2lf\n", minutes);
245 result += minutes / 60.0;
249 if ( strlen(time_str) ) {
251 while ( (time_str[0] != ':') && (time_str[0] != '\0') ) {
252 num[i] = time_str[0];
258 // printf("seconds = %.2lf\n", seconds);
260 result += seconds / 3600.0;
263 return(sign * result);
267 // parse degree in the form of [+/-]hhh:mm:ss
269 fgOPTIONS::parse_degree( const string& degree_str) {
270 double result = parse_time( degree_str );
272 // printf("Degree = %.4f\n", result);
278 // parse time offset command line option
280 fgOPTIONS::parse_time_offset( const string& time_str) {
283 // printf("time offset = %s\n", time_str);
286 result = (int)rint(parse_time(time_str) * 3600.0);
288 result = (int)(parse_time(time_str) * 3600.0);
291 // printf("parse_time_offset(): %d\n", result);
297 // Parse --tile-diameter=n type option
300 fgOPTIONS::parse_tile_radius( const string& arg ) {
301 int radius = atoi( arg );
303 if ( radius < FG_RADIUS_MIN ) { radius = FG_RADIUS_MIN; }
304 if ( radius > FG_RADIUS_MAX ) { radius = FG_RADIUS_MAX; }
306 // printf("parse_tile_radius(): radius = %d\n", radius);
312 // Parse --fdm=abcdefg type option
314 fgOPTIONS::parse_fdm( const string& fm ) {
315 // printf("fdm = %s\n", fm);
317 if ( fm == "slew" ) {
318 return FGInterface::FG_SLEW;
319 } else if ( fm == "jsb" ) {
320 return FGInterface::FG_JSBSIM;
321 } else if ( (fm == "larcsim") || (fm == "LaRCsim") ) {
322 return FGInterface::FG_LARCSIM;
323 } else if ( fm == "external" ) {
324 return FGInterface::FG_EXTERNAL;
326 FG_LOG( FG_GENERAL, FG_ALERT, "Unknown fdm = " << fm );
330 // we'll never get here, but it makes the compiler happy.
335 // Parse --fov=x.xx type option
337 fgOPTIONS::parse_fov( const string& arg ) {
338 double fov = atof(arg);
340 if ( fov < FG_FOV_MIN ) { fov = FG_FOV_MIN; }
341 if ( fov > FG_FOV_MAX ) { fov = FG_FOV_MAX; }
343 // printf("parse_fov(): result = %.4f\n", fov);
349 // Parse serial port option --serial=/dev/ttyS1,nmea,4800,out
351 // Format is "--serial=device,format,baud,direction" where
353 // device = OS device name to be open()'ed
354 // format = {nmea, fgfs}
355 // baud = {300, 1200, 2400, ..., 230400}
356 // direction = {in, out, bi}
359 fgOPTIONS::parse_serial( const string& serial_str ) {
360 string::size_type pos;
362 // cout << "Serial string = " << serial_str << endl;
364 // a flailing attempt to see if the port config string has a
365 // chance at being valid
366 pos = serial_str.find(",");
367 if ( pos == string::npos ) {
368 FG_LOG( FG_GENERAL, FG_ALERT,
369 "Malformed serial port configure string" );
373 port_options_list.push_back( serial_str );
379 // Parse a single option
380 int fgOPTIONS::parse_option( const string& arg ) {
382 if ( (arg == "--help") || (arg == "-h") ) {
383 // help/usage request
384 return(FG_OPTIONS_HELP);
385 } else if ( arg == "--disable-game-mode") {
387 } else if ( arg == "--enable-game-mode" ) {
389 } else if ( arg == "--disable-splash-screen" ) {
390 splash_screen = false;
391 } else if ( arg == "--enable-splash-screen" ) {
392 splash_screen = true;
393 } else if ( arg == "--disable-intro-music" ) {
395 } else if ( arg == "--enable-intro-music" ) {
397 } else if ( arg == "--disable-mouse-pointer" ) {
399 } else if ( arg == "--enable-mouse-pointer" ) {
401 } else if ( arg == "--disable-pause" ) {
403 } else if ( arg == "--enable-pause" ) {
405 } else if ( arg == "--disable-hud" ) {
407 } else if ( arg == "--enable-hud" ) {
409 } else if ( arg == "--disable-panel" ) {
410 panel_status = false;
411 } else if ( arg == "--enable-panel" ) {
413 } else if ( arg == "--disable-sound" ) {
415 } else if ( arg == "--enable-sound" ) {
417 } else if ( arg.find( "--airport-id=") != string::npos ) {
418 airport_id = arg.substr( 13 );
419 } else if ( arg.find( "--lon=" ) != string::npos ) {
420 lon = parse_degree( arg.substr(6) );
421 } else if ( arg.find( "--lat=" ) != string::npos ) {
422 lat = parse_degree( arg.substr(6) );
423 } else if ( arg.find( "--altitude=" ) != string::npos ) {
424 if ( units == FG_UNITS_FEET ) {
425 altitude = atof( arg.substr(11) ) * FEET_TO_METER;
427 altitude = atof( arg.substr(11) );
429 } else if ( arg.find( "--heading=" ) != string::npos ) {
430 heading = atof( arg.substr(10) );
431 } else if ( arg.find( "--roll=" ) != string::npos ) {
432 roll = atof( arg.substr(7) );
433 } else if ( arg.find( "--pitch=" ) != string::npos ) {
434 pitch = atof( arg.substr(8) );
435 } else if ( arg.find( "--fg-root=" ) != string::npos ) {
436 fg_root = arg.substr( 10 );
437 } else if ( arg.find( "--fdm=" ) != string::npos ) {
438 flight_model = parse_fdm( arg.substr(6) );
439 } else if ( arg == "--fog-disable" ) {
440 fog = FG_FOG_DISABLED;
441 } else if ( arg == "--fog-fastest" ) {
442 fog = FG_FOG_FASTEST;
443 } else if ( arg == "--fog-nicest" ) {
445 } else if ( arg.find( "--fov=" ) != string::npos ) {
446 fov = parse_fov( arg.substr(6) );
447 } else if ( arg == "--disable-fullscreen" ) {
449 } else if ( arg== "--enable-fullscreen") {
451 } else if ( arg == "--shading-flat") {
453 } else if ( arg == "--shading-smooth") {
455 } else if ( arg == "--disable-skyblend") {
457 } else if ( arg== "--enable-skyblend" ) {
459 } else if ( arg == "--disable-textures" ) {
461 } else if ( arg == "--enable-textures" ) {
463 } else if ( arg == "--disable-wireframe" ) {
465 } else if ( arg == "--enable-wireframe" ) {
467 } else if ( arg.find( "--geometry=" ) != string::npos ) {
468 string geometry = arg.substr( 11 );
469 if ( geometry == "640x480" ) {
472 } else if ( geometry == "800x600" ) {
475 } else if ( geometry == "1024x768" ) {
479 FG_LOG( FG_GENERAL, FG_ALERT, "Unknown geometry: " << geometry );
482 } else if ( arg == "--units-feet" ) {
483 units = FG_UNITS_FEET;
484 } else if ( arg == "--units-meters" ) {
485 units = FG_UNITS_METERS;
486 } else if ( arg.find( "--tile-radius=" ) != string::npos ) {
487 tile_radius = parse_tile_radius( arg.substr(14) );
488 tile_diameter = tile_radius * 2 + 1;
489 } else if ( arg.find( "--time-offset=" ) != string::npos ) {
490 time_offset = parse_time_offset( (arg.substr(14)) );
491 } else if ( arg == "--hud-tris" ) {
493 } else if ( arg == "--hud-culled" ) {
495 } else if ( arg.find( "--serial=" ) != string::npos ) {
496 parse_serial( arg.substr(9) );
498 FG_LOG( FG_GENERAL, FG_ALERT, "Unknown option '" << arg << "'" );
499 return FG_OPTIONS_ERROR;
502 return FG_OPTIONS_OK;
506 // Parse the command line options
507 int fgOPTIONS::parse_command_line( int argc, char **argv ) {
511 FG_LOG(FG_GENERAL, FG_INFO, "Processing command line arguments");
514 FG_LOG( FG_GENERAL, FG_DEBUG, "argv[" << i << "] = " << argv[i] );
516 result = parse_option(argv[i]);
517 if ( (result == FG_OPTIONS_HELP) || (result == FG_OPTIONS_ERROR) ) {
524 return(FG_OPTIONS_OK);
528 // Parse config file options
529 int fgOPTIONS::parse_config_file( const string& path ) {
530 fg_gzifstream in( path );
532 return(FG_OPTIONS_ERROR);
534 FG_LOG( FG_GENERAL, FG_INFO, "Processing config file: " << path );
542 if ( parse_option( line ) == FG_OPTIONS_ERROR ) {
543 FG_LOG( FG_GENERAL, FG_ALERT,
544 "Config file parse error: " << path << " '"
551 return FG_OPTIONS_OK;
555 // Print usage message
556 void fgOPTIONS::usage ( void ) {
557 printf("Usage: fg [ options ... ]\n");
560 printf("General Options:\n");
561 printf("\t--help -h: print usage\n");
562 printf("\t--fg-root=path: specify the root path for all the data files\n");
563 printf("\t--disable-game-mode: disable full-screen game mode\n");
564 printf("\t--enable-game-mode: enable full-screen game mode\n");
565 printf("\t--disable-splash-screen: disable splash screen\n");
566 printf("\t--enable-splash-screen: enable splash screen\n");
567 printf("\t--disable-intro-music: disable introduction music\n");
568 printf("\t--enable-intro-music: enable introduction music\n");
569 printf("\t--disable-mouse-pointer: disable extra mouse pointer\n");
570 printf("\t--enable-mouse-pointer: enable extra mouse pointer (i.e. for\n");
571 printf("\t\tfull screen voodoo/voodoo-II based cards.)\n");
572 printf("\t--disable-pause: start out in an active state\n");
573 printf("\t--enable-pause: start out in a paused state\n");
576 printf("Features:\n");
577 printf("\t--disable-hud: disable heads up display\n");
578 printf("\t--enable-hud: enable heads up display\n");
579 printf("\t--disable-panel: disable instrument panel\n");
580 printf("\t--enable-panel: enable instrumetn panel\n");
581 printf("\t--disable-sound: disable sound effects\n");
582 printf("\t--enable-sound: enable sound effects\n");
585 printf("Flight Model:\n");
586 printf("\t--fdm=abcd: one of slew, jsb, larcsim, or external\n");
589 printf("Initial Position and Orientation:\n");
590 printf("\t--airport-id=ABCD: specify starting postion by airport id\n");
591 printf("\t--lon=degrees: starting longitude in degrees (west = -)\n");
592 printf("\t--lat=degrees: starting latitude in degrees (south = -)\n");
593 printf("\t--altitude=feet: starting altitude in feet\n");
594 printf("\t\t(unless --units-meters specified\n");
595 printf("\t--heading=degrees: heading (yaw) angle in degress (Psi)\n");
596 printf("\t--roll=degrees: roll angle in degrees (Phi)\n");
597 printf("\t--pitch=degrees: pitch angle in degrees (Theta)\n");
600 printf("Rendering Options:\n");
601 printf("\t--fog-disable: disable fog/haze\n");
602 printf("\t--fog-fastest: enable fastest fog/haze\n");
603 printf("\t--fog-nicest: enable nicest fog/haze\n");
604 printf("\t--fov=xx.x: specify initial field of view angle in degrees\n");
605 printf("\t--disable-fullscreen: disable fullscreen mode\n");
606 printf("\t--enable-fullscreen: enable fullscreen mode\n");
607 printf("\t--shading-flat: enable flat shading\n");
608 printf("\t--shading-smooth: enable smooth shading\n");
609 printf("\t--disable-skyblend: disable sky blending\n");
610 printf("\t--enable-skyblend: enable sky blending\n");
611 printf("\t--disable-textures: disable textures\n");
612 printf("\t--enable-textures: enable textures\n");
613 printf("\t--disable-wireframe: disable wireframe drawing mode\n");
614 printf("\t--enable-wireframe: enable wireframe drawing mode\n");
615 printf("\t--geometry=WWWxHHH: window geometry: 640x480, 800x600, etc.\n");
618 printf("Scenery Options:\n");
619 printf("\t--tile-radius=n: specify tile radius, must be 1 - 4\n");
622 printf("Hud Options:\n");
623 printf("\t--units-feet: Hud displays units in feet\n");
624 printf("\t--units-meters: Hud displays units in meters\n");
625 printf("\t--hud-tris: Hud displays number of triangles rendered\n");
626 printf("\t--hud-culled: Hud displays percentage of triangles culled\n");
629 printf("Time Options:\n");
630 printf("\t--time-offset=[+-]hh:mm:ss: offset local time by this amount\n");
635 fgOPTIONS::~fgOPTIONS( void ) {
640 // Revision 1.41 1999/03/02 01:03:17 curt
641 // Tweaks for building with native SGI compilers.
643 // Revision 1.40 1999/02/26 22:09:51 curt
644 // Added initial support for native SGI compilers.
646 // Revision 1.39 1999/02/05 21:29:12 curt
647 // Modifications to incorporate Jon S. Berndts flight model code.
649 // Revision 1.38 1999/02/01 21:33:35 curt
650 // Renamed FlightGear/Simulator/Flight to FlightGear/Simulator/FDM since
651 // Jon accepted my offer to do this and thought it was a good idea.
653 // Revision 1.37 1999/01/19 20:57:05 curt
654 // MacOS portability changes contributed by "Robert Puyol" <puyol@abvent.fr>
656 // Revision 1.36 1999/01/07 20:25:10 curt
657 // Updated struct fgGENERAL to class FGGeneral.
659 // Revision 1.35 1998/12/06 14:52:57 curt
660 // Fixed a problem with the initial starting altitude. "v->abs_view_pos" wasn't
661 // being calculated correctly at the beginning causing the first terrain
662 // intersection to fail, returning a ground altitude of zero, causing the plane
663 // to free fall for one frame, until the ground altitude was corrected, but now
664 // being under the ground we got a big bounce and the plane always ended up
667 // Revision 1.34 1998/12/05 15:54:22 curt
668 // Renamed class fgFLIGHT to class FGState as per request by JSB.
670 // Revision 1.33 1998/12/04 01:30:44 curt
671 // Added support for the External flight model.
673 // Revision 1.32 1998/11/25 01:34:00 curt
674 // Support for an arbitrary number of serial ports.
676 // Revision 1.31 1998/11/23 21:49:04 curt
677 // Borland portability tweaks.
679 // Revision 1.30 1998/11/16 14:00:02 curt
680 // Added pow() macro bug work around.
681 // Added support for starting FGFS at various resolutions.
682 // Added some initial serial port support.
683 // Specify default log levels in main().
685 // Revision 1.29 1998/11/06 21:18:12 curt
686 // Converted to new logstream debugging facility. This allows release
687 // builds with no messages at all (and no performance impact) by using
688 // the -DFG_NDEBUG flag.
690 // Revision 1.28 1998/11/06 14:47:03 curt
691 // Changes to track Bernie's updates to fgstream.
693 // Revision 1.27 1998/11/02 23:04:04 curt
694 // HUD units now display in feet by default with meters being a command line
697 // Revision 1.26 1998/10/17 01:34:24 curt
700 // Revision 1.25 1998/09/15 02:09:27 curt
701 // Include/fg_callback.hxx
702 // Moved code inline to stop g++ 2.7 from complaining.
704 // Simulator/Time/event.[ch]xx
705 // Changed return type of fgEVENT::printStat(). void caused g++ 2.7 to
706 // complain bitterly.
708 // Minor bugfix and changes.
710 // Simulator/Main/GLUTmain.cxx
711 // Added missing type to idle_state definition - eliminates a warning.
713 // Simulator/Main/fg_init.cxx
714 // Changes to airport lookup.
716 // Simulator/Main/options.cxx
717 // Uses fg_gzifstream when loading config file.
719 // Revision 1.24 1998/09/08 15:04:33 curt
720 // Optimizations by Norman Vine.
722 // Revision 1.23 1998/08/27 17:02:07 curt
723 // Contributions from Bernie Bright <bbright@c031.aone.net.au>
724 // - use strings for fg_root and airport_id and added methods to return
726 // - inlined all access methods,
727 // - made the parsing functions private methods,
728 // - deleted some unused functions.
729 // - propogated some of these changes out a bit further.
731 // Revision 1.22 1998/08/24 20:11:13 curt
732 // Added i/I to toggle full vs. minimal HUD.
733 // Added a --hud-tris vs --hud-culled option.
734 // Moved options accessor funtions to options.hxx.
736 // Revision 1.21 1998/08/20 15:10:34 curt
737 // Added GameGLUT support.
739 // Revision 1.20 1998/07/30 23:48:28 curt
740 // Output position & orientation when pausing.
741 // Eliminated libtool use.
742 // Added options to specify initial position and orientation.
743 // Changed default fov to 55 degrees.
744 // Added command line option to start in paused or unpaused state.
746 // Revision 1.19 1998/07/27 18:41:25 curt
747 // Added a pause command "p"
748 // Fixed some initialization order problems between pui and glut.
749 // Added an --enable/disable-sound option.
751 // Revision 1.18 1998/07/22 01:27:03 curt
752 // Strip out \r when parsing config file in case we are on a windoze system.
754 // Revision 1.17 1998/07/16 17:33:38 curt
755 // "H" / "h" now control hud brightness as well with off being one of the
757 // Better checking for xmesa/fx 3dfx fullscreen/window support for deciding
758 // whether or not to build in the feature.
759 // Translucent menu support.
760 // HAVE_AUDIO_SUPPORT -> ENABLE_AUDIO_SUPPORT
761 // Use fork() / wait() for playing mp3 init music in background under unix.
762 // Changed default tile diameter to 5.
764 // Revision 1.16 1998/07/13 21:01:39 curt
765 // Wrote access functions for current fgOPTIONS.
767 // Revision 1.15 1998/07/06 21:34:19 curt
768 // Added an enable/disable splash screen option.
769 // Added an enable/disable intro music option.
770 // Added an enable/disable instrument panel option.
771 // Added an enable/disable mouse pointer option.
772 // Added using namespace std for compilers that support this.
774 // Revision 1.14 1998/07/04 00:52:26 curt
775 // Add my own version of gluLookAt() (which is nearly identical to the
776 // Mesa/glu version.) But, by calculating the Model View matrix our selves
777 // we can save this matrix without having to read it back in from the video
778 // card. This hopefully allows us to save a few cpu cycles when rendering
779 // out the fragments because we can just use glLoadMatrixd() with the
780 // precalculated matrix for each tile rather than doing a push(), translate(),
781 // pop() for every fragment.
783 // Panel status defaults to off for now until it gets a bit more developed.
785 // Extract OpenGL driver info on initialization.
787 // Revision 1.13 1998/06/27 16:54:34 curt
788 // Replaced "extern displayInstruments" with a entry in fgOPTIONS.
789 // Don't change the view port when displaying the panel.
791 // Revision 1.12 1998/06/17 21:35:13 curt
792 // Refined conditional audio support compilation.
793 // Moved texture parameter setup calls to ../Scenery/materials.cxx
794 // #include <string.h> before various STL includes.
795 // Make HUD default state be enabled.
797 // Revision 1.11 1998/06/13 00:40:33 curt
798 // Tweaked fog command line options.
800 // Revision 1.10 1998/05/16 13:08:36 curt
801 // C++ - ified views.[ch]xx
802 // Shuffled some additional view parameters into the fgVIEW class.
803 // Changed tile-radius to tile-diameter because it is a much better
805 // Added a WORLD_TO_EYE transformation to views.cxx. This allows us
806 // to transform world space to eye space for view frustum culling.
808 // Revision 1.9 1998/05/13 18:29:59 curt
809 // Added a keyboard binding to dynamically adjust field of view.
810 // Added a command line option to specify fov.
811 // Adjusted terrain color.
812 // Root path info moved to fgOPTIONS.
813 // Added ability to parse options out of a config file.
815 // Revision 1.8 1998/05/07 23:14:16 curt
816 // Added "D" key binding to set autopilot heading.
817 // Made frame rate calculation average out over last 10 frames.
818 // Borland C++ floating point exception workaround.
819 // Added a --tile-radius=n option.
821 // Revision 1.7 1998/05/06 03:16:25 curt
822 // Added an averaged global frame rate counter.
823 // Added an option to control tile radius.
825 // Revision 1.6 1998/05/03 00:47:32 curt
826 // Added an option to enable/disable full-screen mode.
828 // Revision 1.5 1998/04/30 12:34:19 curt
829 // Added command line rendering options:
830 // enable/disable fog/haze
831 // specify smooth/flat shading
832 // disable sky blending and just use a solid color
833 // enable wireframe drawing mode
835 // Revision 1.4 1998/04/28 01:20:22 curt
836 // Type-ified fgTIME and fgVIEW.
837 // Added a command line option to disable textures.
839 // Revision 1.3 1998/04/26 05:01:19 curt
840 // Added an rint() / HAVE_RINT check.
842 // Revision 1.2 1998/04/25 15:11:12 curt
843 // Added an command line option to set starting position based on airport ID.
845 // Revision 1.1 1998/04/24 00:49:21 curt
846 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
847 // Trying out some different option parsing code.
848 // Some code reorganization.