src/Main/main.cxx

   1 // main.cxx -- top level sim routines
   2 //
   3 // Written by Curtis Olson, started May 1997.
   4 //
   5 // Copyright (C) 1997 - 2002  Curtis L. Olson  - http://www.flightgear.org/~curt
   6 //
   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.
  11 //
  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.
  16 //
  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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20 //
  21 // $Id$
  22
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include <config.h>
  26 #endif
  27
  28 #include <simgear/compiler.h>
  29
  30 #if defined(__linux__) && defined(__i386__)
  31 #  include <fpu_control.h>
  32 #  include <signal.h>
  33 #endif
  34
  35 #include <iostream>
  36
  37 #include <osg/Camera>
  38 #include <osg/GraphicsContext>
  39 #include <osgDB/Registry>
  40
  41 // Class references
  42 #include <simgear/scene/model/modellib.hxx>
  43 #include <simgear/scene/material/matlib.hxx>
  44 #include <simgear/scene/model/animation.hxx>
  45 #include <simgear/scene/sky/sky.hxx>
  46 #include <simgear/structure/event_mgr.hxx>
  47 #include <simgear/props/AtomicChangeListener.hxx>
  48 #include <simgear/props/props.hxx>
  49 #include <simgear/timing/sg_time.hxx>
  50 #include <simgear/math/sg_random.h>
  51
  52 #include <Time/light.hxx>
  53 #include <Aircraft/replay.hxx>
  54 #include <Cockpit/cockpit.hxx>
  55 #include <Cockpit/hud.hxx>
  56 #include <Model/panelnode.hxx>
  57 #include <Model/modelmgr.hxx>
  58 #include <Model/acmodel.hxx>
  59 #include <Scenery/scenery.hxx>
  60 #include <Scenery/tilemgr.hxx>
  61 #include <Sound/fg_fx.hxx>
  62 #include <Sound/beacon.hxx>
  63 #include <Sound/morse.hxx>
  64 #include <Sound/fg_fx.hxx>
  65 #include <ATCDCL/ATCmgr.hxx>
  66 #include <Time/TimeManager.hxx>
  67 #include <Environment/environment_mgr.hxx>
  68 #include <Environment/ephemeris.hxx>
  69 #include <GUI/new_gui.hxx>
  70 #include <MultiPlayer/multiplaymgr.hxx>
  71
  72 #include "CameraGroup.hxx"
  73 #include "fg_commands.hxx"
  74 #include "fg_io.hxx"
  75 #include "renderer.hxx"
  76 #include "splash.hxx"
  77 #include "main.hxx"
  78 #include "util.hxx"
  79 #include "fg_init.hxx"
  80 #include "fg_os.hxx"
  81 #include "WindowSystemAdapter.hxx"
  82 #include <Main/viewer.hxx>
  83
  84
  85 using namespace flightgear;
  86
  87 using std::cerr;
  88
  89 // Specify our current idle function state.  This is used to run all
  90 // our initializations out of the idle callback so that we can get a
  91 // splash screen up and running right away.
  92 int idle_state = 0;
  93
  94
  95 void fgInitSoundManager();
  96 void fgSetNewSoundDevice(const char *);
  97
  98 // The atexit() function handler should know when the graphical subsystem
  99 // is initialized.
 100 extern int _bootstrap_OSInit;
 101
 102 // What should we do when we have nothing else to do?  Let's get ready
 103 // for the next move and update the display?
 104 static void fgMainLoop( void ) {
 105
 106     static SGConstPropertyNode_ptr longitude
 107         = fgGetNode("/position/longitude-deg");
 108     static SGConstPropertyNode_ptr latitude
 109         = fgGetNode("/position/latitude-deg");
 110     static SGConstPropertyNode_ptr altitude
 111         = fgGetNode("/position/altitude-ft");
 112     static SGConstPropertyNode_ptr vn_fps
 113         = fgGetNode("/velocities/speed-north-fps");
 114     static SGConstPropertyNode_ptr ve_fps
 115         = fgGetNode("/velocities/speed-east-fps");
 116     static SGConstPropertyNode_ptr vd_fps
 117         = fgGetNode("/velocities/speed-down-fps");
 118
 119     static SGPropertyNode_ptr frame_signal
 120         = fgGetNode("/sim/signals/frame", true);
 121
 122     frame_signal->fireValueChanged();
 123     SGCloudLayer::enable_bump_mapping = fgGetBool("/sim/rendering/bump-mapping");
 124
 125     SG_LOG( SG_ALL, SG_DEBUG, "Running Main Loop");
 126     SG_LOG( SG_ALL, SG_DEBUG, "======= ==== ====");
 127
 128
 129   // update "time"
 130     double sim_dt, real_dt;
 131     TimeManager* timeMgr = (TimeManager*) globals->get_subsystem("time");
 132     // compute simulated time (allowing for pause, warp, etc) and
 133     // real elapsed time
 134     timeMgr->computeTimeDeltas(sim_dt, real_dt);
 135
 136     if (globals->get_warp_delta() != 0) {
 137         FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
 138         l->update( 0.5 );
 139     }
 140
 141     // update magvar model
 142     globals->get_mag()->update( longitude->getDoubleValue()
 143                                 * SGD_DEGREES_TO_RADIANS,
 144                                 latitude->getDoubleValue()
 145                                 * SGD_DEGREES_TO_RADIANS,
 146                                 altitude->getDoubleValue() * SG_FEET_TO_METER,
 147                                 globals->get_time_params()->getJD() );
 148
 149
 150     // Update any multiplayer's network queues, the AIMultiplayer
 151     // implementation is an AI model and depends on that
 152     globals->get_multiplayer_mgr()->Update();
 153
 154 #if ENABLE_ATCDCL
 155     // Run ATC subsystem
 156     if (fgGetBool("/sim/atc/enabled"))
 157         globals->get_ATC_mgr()->update(sim_dt);
 158 #endif
 159
 160     globals->get_subsystem_mgr()->update(sim_dt);
 161     globals->get_aircraft_model()->update(sim_dt);
 162
 163     // run Nasal's settimer() loops right before the view manager
 164     globals->get_event_mgr()->update(sim_dt);
 165
 166     // pick up model coordidnates that Nasal code may have set relative to the
 167     // aircraft's
 168     globals->get_model_mgr()->update(sim_dt);
 169
 170     // update the view angle as late as possible, but before sound calculations
 171     globals->get_viewmgr()->update(real_dt);
 172
 173     // Update the sound manager last so it can use the CPU while the GPU
 174     // is processing the scenery (doubled the frame-rate for me) -EMH-
 175 #ifdef ENABLE_AUDIO_SUPPORT
 176     static bool smgr_init = true;
 177     static SGPropertyNode *sound_working = fgGetNode("/sim/sound/working");
 178     if (smgr_init == true) {
 179         if (sound_working->getBoolValue() == true) {
 180             fgInitSoundManager();
 181             smgr_init = false;
 182         }
 183     } else {
 184         static SGPropertyNode *sound_enabled = fgGetNode("/sim/sound/enabled");
 185         static SGSoundMgr *smgr = globals->get_soundmgr();
 186         static bool smgr_enabled = true;
 187
 188         if (sound_working->getBoolValue() == false) {   // request to reinit
 189            smgr->reinit();
 190            smgr->resume();
 191            sound_working->setBoolValue(true);
 192         }
 193
 194         if (smgr_enabled != sound_enabled->getBoolValue()) {
 195             if (smgr_enabled == true) { // request to suspend
 196                 smgr->suspend();
 197                 smgr_enabled = false;
 198             } else {
 199                 smgr->resume();
 200                 smgr_enabled = true;
 201             }
 202         }
 203
 204         if (smgr_enabled == true) {
 205             static SGPropertyNode *volume = fgGetNode("/sim/sound/volume");
 206             smgr->set_volume(volume->getFloatValue());
 207             smgr->update(sim_dt);
 208         }
 209     }
 210 #endif
 211
 212     // END Tile Manager udpates
 213     bool scenery_loaded = fgGetBool("sim/sceneryloaded");
 214     if (!scenery_loaded && globals->get_tile_mgr()->isSceneryLoaded()
 215         && fgGetBool("sim/fdm-initialized")) {
 216         fgSetBool("sim/sceneryloaded",true);
 217         if (fgGetBool("/sim/sound/working")) {
 218             globals->get_soundmgr()->activate();
 219         }
 220         globals->get_props()->tie("/sim/sound/devices/name",
 221               SGRawValueFunctions<const char *>(0, fgSetNewSoundDevice), false);
 222     }
 223     simgear::AtomicChangeListener::fireChangeListeners();
 224
 225     SG_LOG( SG_ALL, SG_DEBUG, "" );
 226 }
 227
 228 void fgInitSoundManager()
 229 {
 230     SGSoundMgr *smgr = globals->get_soundmgr();
 231
 232     smgr->bind();
 233     smgr->init(fgGetString("/sim/sound/device-name", NULL));
 234
 235     vector <const char*>devices = smgr->get_available_devices();
 236     for (unsigned int i=0; i<devices.size(); i++) {
 237         SGPropertyNode *p = fgGetNode("/sim/sound/devices/device", i, true);
 238         p->setStringValue(devices[i]);
 239     }
 240     devices.clear();
 241 }
 242
 243 void fgSetNewSoundDevice(const char *device)
 244 {
 245     globals->get_soundmgr()->suspend();
 246     globals->get_soundmgr()->stop();
 247     globals->get_soundmgr()->init(device);
 248     globals->get_soundmgr()->resume();
 249 }
 250
 251 // Operation for querying OpenGL parameters. This must be done in a
 252 // valid OpenGL context, potentially in another thread.
 253 namespace
 254 {
 255 struct GeneralInitOperation : public GraphicsContextOperation
 256 {
 257     GeneralInitOperation()
 258         : GraphicsContextOperation(std::string("General init"))
 259     {
 260     }
 261     void run(osg::GraphicsContext* gc)
 262     {
 263         SGPropertyNode* simRendering = fgGetNode("/sim/rendering");
 264
 265         simRendering->setStringValue("gl-vendor", (char*) glGetString(GL_VENDOR));
 266         SG_LOG( SG_GENERAL, SG_INFO, glGetString(GL_VENDOR));
 267
 268         simRendering->setStringValue("gl-renderer", (char*) glGetString(GL_RENDERER));
 269         SG_LOG( SG_GENERAL, SG_INFO, glGetString(GL_RENDERER));
 270
 271         simRendering->setStringValue("gl-version", (char*) glGetString(GL_VERSION));
 272         SG_LOG( SG_GENERAL, SG_INFO, glGetString(GL_VERSION));
 273
 274         GLint tmp;
 275         glGetIntegerv( GL_MAX_TEXTURE_SIZE, &tmp );
 276         simRendering->setIntValue("max-texture-size", tmp);
 277
 278         glGetIntegerv( GL_DEPTH_BITS, &tmp );
 279         simRendering->setIntValue("depth-buffer-bits", tmp);
 280     }
 281 };
 282
 283
 284 osg::Node* load_panel(SGPropertyNode *n)
 285 {
 286     osg::Geode* geode = new osg::Geode;
 287     geode->addDrawable(new FGPanelNode(n));
 288     return geode;
 289 }
 290
 291 SGPath resolve_path(const std::string& s)
 292 {
 293   return globals->resolve_maybe_aircraft_path(s);
 294 }
 295
 296 }
 297
 298 // This is the top level master main function that is registered as
 299 // our idle funciton
 300
 301 // The first few passes take care of initialization things (a couple
 302 // per pass) and once everything has been initialized fgMainLoop from
 303 // then on.
 304
 305 static void fgIdleFunction ( void ) {
 306     static osg::ref_ptr<GeneralInitOperation> genOp;
 307     if ( idle_state == 0 ) {
 308         idle_state++;
 309         // Pick some window on which to do queries.
 310         // XXX Perhaps all this graphics initialization code should be
 311         // moved to renderer.cxx?
 312         genOp = new GeneralInitOperation;
 313         osg::Camera* guiCamera = getGUICamera(CameraGroup::getDefault());
 314         WindowSystemAdapter* wsa = WindowSystemAdapter::getWSA();
 315         osg::GraphicsContext* gc = 0;
 316         if (guiCamera)
 317             gc = guiCamera->getGraphicsContext();
 318         if (gc) {
 319             gc->add(genOp.get());
 320         } else {
 321             wsa->windows[0]->gc->add(genOp.get());
 322         }
 323         guiStartInit(gc);
 324     } else if ( idle_state == 1 ) {
 325         if (genOp.valid()) {
 326             if (!genOp->isFinished())
 327                 return;
 328             genOp = 0;
 329         }
 330         if (!guiFinishInit())
 331             return;
 332         idle_state++;
 333         fgSplashProgress("reading aircraft list");
 334
 335
 336     } else if ( idle_state == 2 ) {
 337         idle_state++;
 338
 339         fgSplashProgress("reading airport & navigation data");
 340
 341
 342     } else if ( idle_state == 3 ) {
 343         idle_state++;
 344         fgInitNav();
 345         fgSplashProgress("setting up scenery");
 346
 347
 348     } else if ( idle_state == 4 ) {
 349         idle_state++;
 350         // based on the requested presets, calculate the true starting
 351         // lon, lat
 352         fgInitPosition();
 353         fgInitTowerLocationListener();
 354
 355         TimeManager* t = new TimeManager;
 356         globals->add_subsystem("time", t, SGSubsystemMgr::INIT);
 357         t->init(); // need to init now, not during initSubsystems
 358
 359         // Do some quick general initializations
 360         if( !fgInitGeneral()) {
 361             SG_LOG( SG_GENERAL, SG_ALERT,
 362                 "General initialization failed ..." );
 363             exit(-1);
 364         }
 365
 366         ////////////////////////////////////////////////////////////////////
 367         // Initialize the property-based built-in commands
 368         ////////////////////////////////////////////////////////////////////
 369         fgInitCommands();
 370
 371
 372         ////////////////////////////////////////////////////////////////////
 373         // Initialize the material manager
 374         ////////////////////////////////////////////////////////////////////
 375         globals->set_matlib( new SGMaterialLib );
 376         simgear::SGModelLib::init(globals->get_fg_root());
 377         simgear::SGModelLib::setPropRoot(globals->get_props());
 378         simgear::SGModelLib::setPanelFunc(load_panel);
 379
 380         ////////////////////////////////////////////////////////////////////
 381         // Initialize the TG scenery subsystem.
 382         ////////////////////////////////////////////////////////////////////
 383         globals->set_scenery( new FGScenery );
 384         globals->get_scenery()->init();
 385         globals->get_scenery()->bind();
 386         globals->set_tile_mgr( new FGTileMgr );
 387
 388
 389         ////////////////////////////////////////////////////////////////////
 390         // Initialize the general model subsystem.
 391         ////////////////////////////////////////////////////////////////////
 392         globals->set_model_mgr(new FGModelMgr);
 393         globals->get_model_mgr()->init();
 394         globals->get_model_mgr()->bind();
 395         fgSplashProgress("loading aircraft");
 396
 397
 398     } else if ( idle_state == 5 ) {
 399         idle_state++;
 400
 401         ////////////////////////////////////////////////////////////////////
 402         // Initialize the 3D aircraft model subsystem (has a dependency on
 403         // the scenery subsystem.)
 404         ////////////////////////////////////////////////////////////////////
 405         FGAircraftModel* acm = new FGAircraftModel;
 406         globals->set_aircraft_model(acm);
 407         //globals->add_subsystem("aircraft-model", acm);
 408         acm->init();
 409         acm->bind();
 410
 411         ////////////////////////////////////////////////////////////////////
 412         // Initialize the view manager subsystem.
 413         ////////////////////////////////////////////////////////////////////
 414         FGViewMgr *viewmgr = new FGViewMgr;
 415         globals->set_viewmgr( viewmgr );
 416         viewmgr->init();
 417         viewmgr->bind();
 418         fgSplashProgress("generating sky elements");
 419
 420
 421     } else if ( idle_state == 6 ) {
 422         idle_state++;
 423         // Initialize the sky
 424
 425         Ephemeris* eph = new Ephemeris;
 426         globals->add_subsystem("ephemeris", eph);
 427         eph->init(); // FIXME - remove this once SGSky code below is also a subsystem
 428         eph->bind();
 429
 430         // TODO: move to environment mgr
 431         thesky = new SGSky;
 432         SGPath texture_path(globals->get_fg_root());
 433         texture_path.append("Textures");
 434         texture_path.append("Sky");
 435         for (int i = 0; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
 436             SGCloudLayer * layer = new SGCloudLayer(texture_path.str());
 437             thesky->add_cloud_layer(layer);
 438         }
 439
 440         SGPath sky_tex_path( globals->get_fg_root() );
 441         sky_tex_path.append( "Textures" );
 442         sky_tex_path.append( "Sky" );
 443         thesky->texture_path( sky_tex_path.str() );
 444
 445         // The sun and moon diameters are scaled down numbers of the
 446         // actual diameters. This was needed to fit both the sun and the
 447         // moon within the distance to the far clip plane.
 448         // Moon diameter:    3,476 kilometers
 449         // Sun diameter: 1,390,000 kilometers
 450         thesky->build( 80000.0, 80000.0,
 451                        463.3, 361.8,
 452                        *globals->get_ephem(),
 453                        fgGetNode("/environment", true));
 454
 455         // Initialize MagVar model
 456         SGMagVar *magvar = new SGMagVar();
 457         globals->set_mag( magvar );
 458
 459
 460                                     // kludge to initialize mag compass
 461                                     // (should only be done for in-flight
 462                                     // startup)
 463         // update magvar model
 464         globals->get_mag()->update( fgGetDouble("/position/longitude-deg")
 465                                     * SGD_DEGREES_TO_RADIANS,
 466                                     fgGetDouble("/position/latitude-deg")
 467                                     * SGD_DEGREES_TO_RADIANS,
 468                                     fgGetDouble("/position/altitude-ft")
 469                                     * SG_FEET_TO_METER,
 470                                     globals->get_time_params()->getJD() );
 471         double var = globals->get_mag()->get_magvar() * SGD_RADIANS_TO_DEGREES;
 472         fgSetDouble("/instrumentation/heading-indicator/offset-deg", -var);
 473         fgSetDouble("/instrumentation/heading-indicator-fg/offset-deg", -var);
 474
 475
 476         // airport = new ssgBranch;
 477         // airport->setName( "Airport Lighting" );
 478         // lighting->addKid( airport );
 479
 480         // build our custom render states
 481         fgSplashProgress("initializing subsystems");
 482
 483
 484     } else if ( idle_state == 7 ) {
 485         idle_state++;
 486         // Initialize audio support
 487 #ifdef ENABLE_AUDIO_SUPPORT
 488
 489         // Start the intro music
 490         if ( fgGetBool("/sim/startup/intro-music") ) {
 491             SGPath mp3file( globals->get_fg_root() );
 492             mp3file.append( "Sounds/intro.mp3" );
 493
 494             SG_LOG( SG_GENERAL, SG_INFO,
 495                 "Starting intro music: " << mp3file.str() );
 496
 497 # if defined( __CYGWIN__ )
 498             string command = "start /m `cygpath -w " + mp3file.str() + "`";
 499 # elif defined( _WIN32 )
 500             string command = "start /m " + mp3file.str();
 501 # else
 502             string command = "mpg123 " + mp3file.str() + "> /dev/null 2>&1";
 503 # endif
 504
 505             system ( command.c_str() );
 506         }
 507 #endif
 508         // This is the top level init routine which calls all the
 509         // other subsystem initialization routines.  If you are adding
 510         // a subsystem to flightgear, its initialization call should be
 511         // located in this routine.
 512         if( !fgInitSubsystems()) {
 513             SG_LOG( SG_GENERAL, SG_ALERT,
 514                 "Subsystem initialization failed ..." );
 515             exit(-1);
 516         }
 517         fgSplashProgress("setting up time & renderer");
 518
 519
 520     } else if ( idle_state == 8 ) {
 521         idle_state = 1000;
 522
 523         // setup OpenGL view parameters
 524         globals->get_renderer()->init();
 525
 526         globals->get_renderer()->resize( fgGetInt("/sim/startup/xsize"),
 527                                          fgGetInt("/sim/startup/ysize") );
 528
 529         fgSplashProgress("loading scenery objects");
 530         int session = fgGetInt("/sim/session",0);
 531         session++;
 532         fgSetInt("/sim/session",session);
 533     }
 534
 535     if ( idle_state == 1000 ) {
 536         // We've finished all our initialization steps, from now on we
 537         // run the main loop.
 538         fgSetBool("sim/sceneryloaded", false);
 539         fgRegisterIdleHandler( fgMainLoop );
 540     }
 541 }
 542
 543
 544 static void upper_case_property(const char *name)
 545 {
 546     using namespace simgear;
 547     SGPropertyNode *p = fgGetNode(name, false);
 548     if (!p) {
 549         p = fgGetNode(name, true);
 550         p->setStringValue("");
 551     } else {
 552         props::Type t = p->getType();
 553         if (t == props::NONE || t == props::UNSPECIFIED)
 554             p->setStringValue("");
 555         else
 556             assert(t == props::STRING);
 557     }
 558     p->addChangeListener(new FGMakeUpperCase);
 559 }
 560
 561
 562 // Main top level initialization
 563 int fgMainInit( int argc, char **argv ) {
 564
 565     // set default log levels
 566     sglog().setLogLevels( SG_ALL, SG_ALERT );
 567
 568     string version;
 569 #ifdef FLIGHTGEAR_VERSION
 570     version = FLIGHTGEAR_VERSION;
 571 #else
 572     version = "unknown version";
 573 #endif
 574     SG_LOG( SG_GENERAL, SG_INFO, "FlightGear:  Version "
 575             << version );
 576     SG_LOG( SG_GENERAL, SG_INFO, "Built with " << SG_COMPILER_STR << endl );
 577
 578     // Allocate global data structures.  This needs to happen before
 579     // we parse command line options
 580
 581     globals = new FGGlobals;
 582
 583     // seed the random number generator
 584     sg_srandom_time();
 585
 586     FGControls *controls = new FGControls;
 587     globals->set_controls( controls );
 588
 589     string_list *col = new string_list;
 590     globals->set_channel_options_list( col );
 591
 592     fgValidatePath("", false);  // initialize static variables
 593     upper_case_property("/sim/presets/airport-id");
 594     upper_case_property("/sim/presets/runway");
 595     upper_case_property("/sim/tower/airport-id");
 596     upper_case_property("/autopilot/route-manager/input");
 597
 598     // Scan the config file(s) and command line options to see if
 599     // fg_root was specified (ignore all other options for now)
 600     fgInitFGRoot(argc, argv);
 601
 602     // Check for the correct base package version
 603     static char required_version[] = "2.0.0";
 604     string base_version = fgBasePackageVersion();
 605     if ( !(base_version == required_version) ) {
 606         // tell the operator how to use this application
 607
 608         SG_LOG( SG_GENERAL, SG_ALERT, "" ); // To popup the console on windows
 609         cerr << endl << "Base package check failed ... " \
 610              << "Found version " << base_version << " at: " \
 611              << globals->get_fg_root() << endl;
 612         cerr << "Please upgrade to version: " << required_version << endl;
 613 #ifdef _MSC_VER
 614         cerr << "Hit a key to continue..." << endl;
 615         cin.get();
 616 #endif
 617         exit(-1);
 618     }
 619
 620     // Load the configuration parameters.  (Command line options
 621     // override config file options.  Config file options override
 622     // defaults.)
 623     if ( !fgInitConfig(argc, argv) ) {
 624         SG_LOG( SG_GENERAL, SG_ALERT, "Config option parsing failed ..." );
 625         exit(-1);
 626     }
 627
 628     // Initialize the Window/Graphics environment.
 629     fgOSInit(&argc, argv);
 630     _bootstrap_OSInit++;
 631
 632     fgRegisterWindowResizeHandler( &FGRenderer::resize );
 633     fgRegisterIdleHandler( &fgIdleFunction );
 634     fgRegisterDrawHandler( &FGRenderer::update );
 635
 636     // Initialize plib net interface
 637     netInit( &argc, argv );
 638
 639     // Clouds3D requires an alpha channel
 640     fgOSOpenWindow(true /* request stencil buffer */);
 641
 642     // Initialize the splash screen right away
 643     fntInit();
 644     fgSplashInit();
 645
 646     // pass control off to the master event handler
 647     int result = fgOSMainLoop();
 648
 649     // clean up here; ensure we null globals to avoid
 650     // confusing the atexit() handler
 651     delete globals;
 652     globals = NULL;
 653
 654     return result;
 655 }
 656
 657