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/magvar/magvar.hxx>
  51 #include <simgear/math/sg_random.h>
  52 #include <simgear/io/raw_socket.hxx>
  53 #include <simgear/misc/sg_sleep.hxx>
  54
  55 #include <Time/light.hxx>
  56 #include <Aircraft/replay.hxx>
  57 #include <Aircraft/controls.hxx>
  58 #include <Model/panelnode.hxx>
  59 #include <Model/acmodel.hxx>
  60 #include <Scenery/scenery.hxx>
  61 #include <Scenery/tilemgr.hxx>
  62 #include <Sound/fg_fx.hxx>
  63 #include <Sound/beacon.hxx>
  64 #include <Sound/morse.hxx>
  65 #include <Sound/fg_fx.hxx>
  66 #include <ATCDCL/ATCmgr.hxx>
  67 #include <Time/TimeManager.hxx>
  68 #include <Environment/environment_mgr.hxx>
  69 #include <Environment/ephemeris.hxx>
  70 #include <GUI/gui.h>
  71 #include <GUI/new_gui.hxx>
  72 #include <MultiPlayer/multiplaymgr.hxx>
  73
  74 #include "CameraGroup.hxx"
  75 #include "fg_commands.hxx"
  76 #include "fg_io.hxx"
  77 #include "renderer.hxx"
  78 #include "splash.hxx"
  79 #include "main.hxx"
  80 #include "util.hxx"
  81 #include "fg_init.hxx"
  82 #include "fg_os.hxx"
  83 #include "WindowSystemAdapter.hxx"
  84 #include <Main/viewer.hxx>
  85
  86
  87 using namespace flightgear;
  88
  89 using std::cerr;
  90
  91 // Specify our current idle function state.  This is used to run all
  92 // our initializations out of the idle callback so that we can get a
  93 // splash screen up and running right away.
  94 int idle_state = 0;
  95
  96
  97 void fgInitSoundManager();
  98 void fgSetNewSoundDevice(const char *);
  99
 100 // The atexit() function handler should know when the graphical subsystem
 101 // is initialized.
 102 extern int _bootstrap_OSInit;
 103
 104 // What should we do when we have nothing else to do?  Let's get ready
 105 // for the next move and update the display?
 106 static void fgMainLoop( void ) {
 107
 108     static SGConstPropertyNode_ptr longitude
 109         = fgGetNode("/position/longitude-deg");
 110     static SGConstPropertyNode_ptr latitude
 111         = fgGetNode("/position/latitude-deg");
 112     static SGConstPropertyNode_ptr altitude
 113         = fgGetNode("/position/altitude-ft");
 114     static SGConstPropertyNode_ptr vn_fps
 115         = fgGetNode("/velocities/speed-north-fps");
 116     static SGConstPropertyNode_ptr ve_fps
 117         = fgGetNode("/velocities/speed-east-fps");
 118     static SGConstPropertyNode_ptr vd_fps
 119         = fgGetNode("/velocities/speed-down-fps");
 120
 121     static SGPropertyNode_ptr frame_signal
 122         = fgGetNode("/sim/signals/frame", true);
 123
 124     static SGPropertyNode_ptr _statisticsFlag
 125         = fgGetNode("/sim/timing-statistics/enabled", true);
 126     static SGPropertyNode_ptr _statisticsInterval
 127         = fgGetNode("/sim/timing-statistics/interval-s", true);
 128     static SGPropertyNode_ptr _statiticsMinJitter
 129         = fgGetNode("/sim/timing-statistics/min-jitter-ms", true);
 130     static SGPropertyNode_ptr _statiticsMinTime
 131         = fgGetNode("/sim/timing-statistics/min-time-ms", true);
 132
 133     frame_signal->fireValueChanged();
 134     SGCloudLayer::enable_bump_mapping = fgGetBool("/sim/rendering/bump-mapping");
 135
 136     SG_LOG( SG_ALL, SG_DEBUG, "Running Main Loop");
 137     SG_LOG( SG_ALL, SG_DEBUG, "======= ==== ====");
 138
 139
 140   // update "time"
 141     double sim_dt, real_dt;
 142     TimeManager* timeMgr = (TimeManager*) globals->get_subsystem("time");
 143     // compute simulated time (allowing for pause, warp, etc) and
 144     // real elapsed time
 145     timeMgr->computeTimeDeltas(sim_dt, real_dt);
 146
 147     // update magvar model
 148     globals->get_mag()->update( longitude->getDoubleValue()
 149                                 * SGD_DEGREES_TO_RADIANS,
 150                                 latitude->getDoubleValue()
 151                                 * SGD_DEGREES_TO_RADIANS,
 152                                 altitude->getDoubleValue() * SG_FEET_TO_METER,
 153                                 globals->get_time_params()->getJD() );
 154
 155     // Run ATC subsystem
 156     globals->get_ATC_mgr()->update(sim_dt);
 157
 158     globals->get_subsystem_mgr()->update(sim_dt);
 159
 160     // Update the sound manager last so it can use the CPU while the GPU
 161     // is processing the scenery (doubled the frame-rate for me) -EMH-
 162 #ifdef ENABLE_AUDIO_SUPPORT
 163     static bool smgr_init = true;
 164     static SGPropertyNode *sound_working = fgGetNode("/sim/sound/working");
 165     if (smgr_init == true) {
 166         if (sound_working->getBoolValue() == true) {
 167             fgInitSoundManager();
 168             smgr_init = false;
 169         }
 170     } else {
 171         static SGPropertyNode *sound_enabled = fgGetNode("/sim/sound/enabled");
 172         static SGSoundMgr *smgr = globals->get_soundmgr();
 173         static bool smgr_enabled = true;
 174
 175         if (sound_working->getBoolValue() == false) {   // request to reinit
 176            smgr->reinit();
 177            smgr->resume();
 178            sound_working->setBoolValue(true);
 179         }
 180
 181         if (smgr_enabled != sound_enabled->getBoolValue()) {
 182             if (smgr_enabled == true) { // request to suspend
 183                 smgr->suspend();
 184                 smgr_enabled = false;
 185             } else {
 186                 smgr->resume();
 187                 smgr_enabled = true;
 188             }
 189         }
 190
 191         if (smgr_enabled == true) {
 192             static SGPropertyNode *volume = fgGetNode("/sim/sound/volume");
 193             smgr->set_volume(volume->getFloatValue());
 194             smgr->update(sim_dt);
 195         }
 196     }
 197 #endif
 198
 199     // END Tile Manager updates
 200     bool scenery_loaded = fgGetBool("sim/sceneryloaded");
 201     if (!scenery_loaded)
 202     {
 203         if (globals->get_tile_mgr()->isSceneryLoaded()
 204              && fgGetBool("sim/fdm-initialized")) {
 205             fgSetBool("sim/sceneryloaded",true);
 206             if (fgGetBool("/sim/sound/working")) {
 207                 globals->get_soundmgr()->activate();
 208             }
 209             globals->get_props()->tie("/sim/sound/devices/name",
 210                   SGRawValueFunctions<const char *>(0, fgSetNewSoundDevice), false);
 211         }
 212         else
 213         {
 214             // be nice to loader threads while waiting for initial scenery, reduce to 2fps
 215             simgear::sleepForMSec(500);
 216         }
 217     }
 218
 219     // print timing statistics
 220     static bool _lastStatisticsFlag = false;
 221     if (_lastStatisticsFlag != _statisticsFlag->getBoolValue())
 222     {
 223         // flag has changed, update subsystem manager
 224         _lastStatisticsFlag = _statisticsFlag->getBoolValue();
 225         globals->get_subsystem_mgr()->collectDebugTiming(_lastStatisticsFlag);
 226     }
 227     if (_lastStatisticsFlag)
 228     {
 229         static double elapsed = 0;
 230         elapsed += real_dt;
 231         if (elapsed >= _statisticsInterval->getDoubleValue())
 232         {
 233             // print and reset timing statistics
 234             globals->get_subsystem_mgr()->printTimingStatistics(_statiticsMinTime->getDoubleValue(),
 235                                                                 _statiticsMinJitter->getDoubleValue());
 236             elapsed = 0;
 237         }
 238     }
 239
 240     simgear::AtomicChangeListener::fireChangeListeners();
 241
 242     SG_LOG( SG_ALL, SG_DEBUG, "" );
 243 }
 244
 245 void fgInitSoundManager()
 246 {
 247     SGSoundMgr *smgr = globals->get_soundmgr();
 248
 249     smgr->bind();
 250     smgr->init(fgGetString("/sim/sound/device-name", NULL));
 251
 252     vector <const char*>devices = smgr->get_available_devices();
 253     for (unsigned int i=0; i<devices.size(); i++) {
 254         SGPropertyNode *p = fgGetNode("/sim/sound/devices/device", i, true);
 255         p->setStringValue(devices[i]);
 256     }
 257     devices.clear();
 258 }
 259
 260 void fgSetNewSoundDevice(const char *device)
 261 {
 262     globals->get_soundmgr()->suspend();
 263     globals->get_soundmgr()->stop();
 264     globals->get_soundmgr()->init(device);
 265     globals->get_soundmgr()->resume();
 266 }
 267
 268 // Operation for querying OpenGL parameters. This must be done in a
 269 // valid OpenGL context, potentially in another thread.
 270 namespace
 271 {
 272 struct GeneralInitOperation : public GraphicsContextOperation
 273 {
 274     GeneralInitOperation()
 275         : GraphicsContextOperation(std::string("General init"))
 276     {
 277     }
 278     void run(osg::GraphicsContext* gc)
 279     {
 280         SGPropertyNode* simRendering = fgGetNode("/sim/rendering");
 281
 282         simRendering->setStringValue("gl-vendor", (char*) glGetString(GL_VENDOR));
 283         SG_LOG( SG_GENERAL, SG_INFO, glGetString(GL_VENDOR));
 284
 285         simRendering->setStringValue("gl-renderer", (char*) glGetString(GL_RENDERER));
 286         SG_LOG( SG_GENERAL, SG_INFO, glGetString(GL_RENDERER));
 287
 288         simRendering->setStringValue("gl-version", (char*) glGetString(GL_VERSION));
 289         SG_LOG( SG_GENERAL, SG_INFO, glGetString(GL_VERSION));
 290
 291         GLint tmp;
 292         glGetIntegerv( GL_MAX_TEXTURE_SIZE, &tmp );
 293         simRendering->setIntValue("max-texture-size", tmp);
 294
 295         glGetIntegerv( GL_DEPTH_BITS, &tmp );
 296         simRendering->setIntValue("depth-buffer-bits", tmp);
 297     }
 298 };
 299
 300
 301 osg::Node* load_panel(SGPropertyNode *n)
 302 {
 303     osg::Geode* geode = new osg::Geode;
 304     geode->addDrawable(new FGPanelNode(n));
 305     return geode;
 306 }
 307
 308 SGPath resolve_path(const std::string& s)
 309 {
 310   return globals->resolve_maybe_aircraft_path(s);
 311 }
 312
 313 }
 314
 315 // This is the top level master main function that is registered as
 316 // our idle funciton
 317
 318 // The first few passes take care of initialization things (a couple
 319 // per pass) and once everything has been initialized fgMainLoop from
 320 // then on.
 321
 322 static void fgIdleFunction ( void ) {
 323     static osg::ref_ptr<GeneralInitOperation> genOp;
 324     if ( idle_state == 0 ) {
 325         idle_state++;
 326         // Pick some window on which to do queries.
 327         // XXX Perhaps all this graphics initialization code should be
 328         // moved to renderer.cxx?
 329         genOp = new GeneralInitOperation;
 330         osg::Camera* guiCamera = getGUICamera(CameraGroup::getDefault());
 331         WindowSystemAdapter* wsa = WindowSystemAdapter::getWSA();
 332         osg::GraphicsContext* gc = 0;
 333         if (guiCamera)
 334             gc = guiCamera->getGraphicsContext();
 335         if (gc) {
 336             gc->add(genOp.get());
 337         } else {
 338             wsa->windows[0]->gc->add(genOp.get());
 339         }
 340         guiStartInit(gc);
 341     } else if ( idle_state == 1 ) {
 342         if (genOp.valid()) {
 343             if (!genOp->isFinished())
 344                 return;
 345             genOp = 0;
 346         }
 347         if (!guiFinishInit())
 348             return;
 349         idle_state++;
 350         fgSplashProgress("reading aircraft list");
 351
 352
 353     } else if ( idle_state == 2 ) {
 354         idle_state++;
 355
 356         fgSplashProgress("reading airport & navigation data");
 357
 358
 359     } else if ( idle_state == 3 ) {
 360         idle_state++;
 361         fgInitNav();
 362         fgSplashProgress("setting up scenery");
 363
 364
 365     } else if ( idle_state == 4 ) {
 366         idle_state++;
 367         // based on the requested presets, calculate the true starting
 368         // lon, lat
 369         fgInitPosition();
 370         fgInitTowerLocationListener();
 371
 372         TimeManager* t = new TimeManager;
 373         globals->add_subsystem("time", t, SGSubsystemMgr::INIT);
 374         t->init(); // need to init now, not during initSubsystems
 375
 376         // Do some quick general initializations
 377         if( !fgInitGeneral()) {
 378             SG_LOG( SG_GENERAL, SG_ALERT,
 379                 "General initialization failed ..." );
 380             exit(-1);
 381         }
 382
 383         ////////////////////////////////////////////////////////////////////
 384         // Initialize the property-based built-in commands
 385         ////////////////////////////////////////////////////////////////////
 386         fgInitCommands();
 387
 388
 389         ////////////////////////////////////////////////////////////////////
 390         // Initialize the material manager
 391         ////////////////////////////////////////////////////////////////////
 392         globals->set_matlib( new SGMaterialLib );
 393         simgear::SGModelLib::init(globals->get_fg_root());
 394         simgear::SGModelLib::setPropRoot(globals->get_props());
 395         simgear::SGModelLib::setPanelFunc(load_panel);
 396
 397         ////////////////////////////////////////////////////////////////////
 398         // Initialize the TG scenery subsystem.
 399         ////////////////////////////////////////////////////////////////////
 400         globals->set_scenery( new FGScenery );
 401         globals->get_scenery()->init();
 402         globals->get_scenery()->bind();
 403         globals->set_tile_mgr( new FGTileMgr );
 404
 405
 406         fgSplashProgress("loading aircraft");
 407
 408
 409     } else if ( idle_state == 5 ) {
 410         idle_state++;
 411
 412         fgSplashProgress("generating sky elements");
 413
 414
 415     } else if ( idle_state == 6 ) {
 416         idle_state++;
 417         // Initialize the sky
 418
 419         Ephemeris* eph = new Ephemeris;
 420         globals->add_subsystem("ephemeris", eph);
 421         eph->init(); // FIXME - remove this once SGSky code below is also a subsystem
 422         eph->bind();
 423
 424         // TODO: move to environment mgr
 425         thesky = new SGSky;
 426         SGPath texture_path(globals->get_fg_root());
 427         texture_path.append("Textures");
 428         texture_path.append("Sky");
 429         for (int i = 0; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
 430             SGCloudLayer * layer = new SGCloudLayer(texture_path.str());
 431             thesky->add_cloud_layer(layer);
 432         }
 433
 434         SGPath sky_tex_path( globals->get_fg_root() );
 435         sky_tex_path.append( "Textures" );
 436         sky_tex_path.append( "Sky" );
 437         thesky->texture_path( sky_tex_path.str() );
 438
 439         // The sun and moon diameters are scaled down numbers of the
 440         // actual diameters. This was needed to fit both the sun and the
 441         // moon within the distance to the far clip plane.
 442         // Moon diameter:    3,476 kilometers
 443         // Sun diameter: 1,390,000 kilometers
 444         thesky->build( 80000.0, 80000.0,
 445                        463.3, 361.8,
 446                        *globals->get_ephem(),
 447                        fgGetNode("/environment", true));
 448
 449         // Initialize MagVar model
 450         SGMagVar *magvar = new SGMagVar();
 451         globals->set_mag( magvar );
 452
 453
 454                                     // kludge to initialize mag compass
 455                                     // (should only be done for in-flight
 456                                     // startup)
 457         // update magvar model
 458         globals->get_mag()->update( fgGetDouble("/position/longitude-deg")
 459                                     * SGD_DEGREES_TO_RADIANS,
 460                                     fgGetDouble("/position/latitude-deg")
 461                                     * SGD_DEGREES_TO_RADIANS,
 462                                     fgGetDouble("/position/altitude-ft")
 463                                     * SG_FEET_TO_METER,
 464                                     globals->get_time_params()->getJD() );
 465         double var = globals->get_mag()->get_magvar() * SGD_RADIANS_TO_DEGREES;
 466         fgSetDouble("/instrumentation/heading-indicator/offset-deg", -var);
 467         fgSetDouble("/instrumentation/heading-indicator-fg/offset-deg", -var);
 468
 469
 470         // airport = new ssgBranch;
 471         // airport->setName( "Airport Lighting" );
 472         // lighting->addKid( airport );
 473
 474         // build our custom render states
 475         fgSplashProgress("initializing subsystems");
 476
 477
 478     } else if ( idle_state == 7 ) {
 479         idle_state++;
 480         // Initialize audio support
 481 #ifdef ENABLE_AUDIO_SUPPORT
 482
 483         // Start the intro music
 484         if ( fgGetBool("/sim/startup/intro-music") ) {
 485             SGPath mp3file( globals->get_fg_root() );
 486             mp3file.append( "Sounds/intro.mp3" );
 487
 488             SG_LOG( SG_GENERAL, SG_INFO,
 489                 "Starting intro music: " << mp3file.str() );
 490
 491 # if defined( __CYGWIN__ )
 492             string command = "start /m `cygpath -w " + mp3file.str() + "`";
 493 # elif defined( _WIN32 )
 494             string command = "start /m " + mp3file.str();
 495 # else
 496             string command = "mpg123 " + mp3file.str() + "> /dev/null 2>&1";
 497 # endif
 498
 499             system ( command.c_str() );
 500         }
 501 #endif
 502         // This is the top level init routine which calls all the
 503         // other subsystem initialization routines.  If you are adding
 504         // a subsystem to flightgear, its initialization call should be
 505         // located in this routine.
 506         if( !fgInitSubsystems()) {
 507             SG_LOG( SG_GENERAL, SG_ALERT,
 508                 "Subsystem initialization failed ..." );
 509             exit(-1);
 510         }
 511
 512         // Torsten Dreyer:
 513         // ugly hack for automatic runway selection on startup based on
 514         // metar data. Makes startup.nas obsolete and guarantees the same
 515         // runway selection as for AI traffic. However, this code belongs to
 516         // somewhere(?) else - if I only new where...
 517         if( true == fgGetBool( "/environment/metar/valid" ) ) {
 518             // the realwx_ctrl fetches metar in the foreground on init,
 519             // If it was able to fetch a metar or one was given on the commandline,
 520             // the valid flag is set here, otherwise it is false
 521             double hdg = fgGetDouble( "/environment/metar/base-wind-dir-deg", 9999.0 );
 522             string apt = fgGetString( "/sim/startup/options/airport" );
 523             string rwy = fgGetString( "/sim/startup/options/runway" );
 524             double strthdg = fgGetDouble( "/sim/startup/options/heading-deg", 9999.0 );
 525             string parkpos = fgGetString( "/sim/presets/parkpos" );
 526             bool onground = fgGetBool( "/sim/presets/onground", false );
 527             // don't check for wind-speed < 1kt, this belongs to the runway-selection code
 528             // the other logic is taken from former startup.nas
 529             if( hdg < 360.0 && apt.length() > 0 && strthdg > 360.0 && rwy.length() == 0 && onground && parkpos.length() == 0 ) {
 530                 extern bool fgSetPosFromAirportIDandHdg( const string& id, double tgt_hdg );
 531                 fgSetPosFromAirportIDandHdg( apt, hdg );
 532             }
 533         }
 534         fgSplashProgress("setting up time & renderer");
 535
 536     } else if ( idle_state == 8 ) {
 537         idle_state = 1000;
 538
 539         // setup OpenGL view parameters
 540         globals->get_renderer()->init();
 541
 542         globals->get_renderer()->resize( fgGetInt("/sim/startup/xsize"),
 543                                          fgGetInt("/sim/startup/ysize") );
 544
 545         fgSplashProgress("loading scenery objects");
 546         int session = fgGetInt("/sim/session",0);
 547         session++;
 548         fgSetInt("/sim/session",session);
 549     }
 550
 551     if ( idle_state == 1000 ) {
 552         // We've finished all our initialization steps, from now on we
 553         // run the main loop.
 554         fgSetBool("sim/sceneryloaded", false);
 555         fgRegisterIdleHandler( fgMainLoop );
 556     }
 557 }
 558
 559
 560 static void upper_case_property(const char *name)
 561 {
 562     using namespace simgear;
 563     SGPropertyNode *p = fgGetNode(name, false);
 564     if (!p) {
 565         p = fgGetNode(name, true);
 566         p->setStringValue("");
 567     } else {
 568         props::Type t = p->getType();
 569         if (t == props::NONE || t == props::UNSPECIFIED)
 570             p->setStringValue("");
 571         else
 572             assert(t == props::STRING);
 573     }
 574     p->addChangeListener(new FGMakeUpperCase);
 575 }
 576
 577
 578 // Main top level initialization
 579 int fgMainInit( int argc, char **argv ) {
 580
 581     // set default log levels
 582     sglog().setLogLevels( SG_ALL, SG_ALERT );
 583
 584     string version;
 585 #ifdef FLIGHTGEAR_VERSION
 586     version = FLIGHTGEAR_VERSION;
 587 #else
 588     version = "unknown version";
 589 #endif
 590     SG_LOG( SG_GENERAL, SG_INFO, "FlightGear:  Version "
 591             << version );
 592     SG_LOG( SG_GENERAL, SG_INFO, "Built with " << SG_COMPILER_STR << endl );
 593
 594     // Allocate global data structures.  This needs to happen before
 595     // we parse command line options
 596
 597     globals = new FGGlobals;
 598
 599     // seed the random number generator
 600     sg_srandom_time();
 601
 602     FGControls *controls = new FGControls;
 603     globals->set_controls( controls );
 604
 605     string_list *col = new string_list;
 606     globals->set_channel_options_list( col );
 607
 608     fgValidatePath("", false);  // initialize static variables
 609     upper_case_property("/sim/presets/airport-id");
 610     upper_case_property("/sim/presets/runway");
 611     upper_case_property("/sim/tower/airport-id");
 612     upper_case_property("/autopilot/route-manager/input");
 613
 614     // Scan the config file(s) and command line options to see if
 615     // fg_root was specified (ignore all other options for now)
 616     fgInitFGRoot(argc, argv);
 617
 618     // Check for the correct base package version
 619     static char required_version[] = "2.0.0";
 620     string base_version = fgBasePackageVersion();
 621     if ( !(base_version == required_version) ) {
 622         // tell the operator how to use this application
 623
 624         SG_LOG( SG_GENERAL, SG_ALERT, "" ); // To popup the console on windows
 625         cerr << endl << "Base package check failed ... " \
 626              << "Found version " << base_version << " at: " \
 627              << globals->get_fg_root() << endl;
 628         cerr << "Please upgrade to version: " << required_version << endl;
 629 #ifdef _MSC_VER
 630         cerr << "Hit a key to continue..." << endl;
 631         cin.get();
 632 #endif
 633         exit(-1);
 634     }
 635
 636     // Load the configuration parameters.  (Command line options
 637     // override config file options.  Config file options override
 638     // defaults.)
 639     if ( !fgInitConfig(argc, argv) ) {
 640         SG_LOG( SG_GENERAL, SG_ALERT, "Config option parsing failed ..." );
 641         exit(-1);
 642     }
 643
 644     // Initialize the Window/Graphics environment.
 645     fgOSInit(&argc, argv);
 646     _bootstrap_OSInit++;
 647
 648     fgRegisterWindowResizeHandler( &FGRenderer::resize );
 649     fgRegisterIdleHandler( &fgIdleFunction );
 650     fgRegisterDrawHandler( &FGRenderer::update );
 651
 652     // Initialize sockets (WinSock needs this)
 653     simgear::Socket::initSockets();
 654
 655     // Clouds3D requires an alpha channel
 656     fgOSOpenWindow(true /* request stencil buffer */);
 657
 658     // Initialize the splash screen right away
 659     fntInit();
 660     fgSplashInit();
 661
 662     // pass control off to the master event handler
 663     int result = fgOSMainLoop();
 664
 665     // clean up here; ensure we null globals to avoid
 666     // confusing the atexit() handler
 667     delete globals;
 668     globals = NULL;
 669
 670     return result;
 671 }
 672
 673