src/FDM/JSBSim/JSBSim.cxx

   1 // JSBsim.cxx -- interface to the JSBsim flight model
   2 //
   3 // Written by Curtis Olson, started February 1999.
   4 //
   5 // Copyright (C) 1999  Curtis L. Olson  - curt@flightgear.org
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU Lesser 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 // Lesser General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU Lesser General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
  20 //
  21 // $Id: JSBSim.cxx,v 1.64 2010/10/31 04:49:25 jberndt Exp $
  22
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include <config.h>
  26 #endif
  27
  28 #include <simgear/compiler.h>
  29 #include <simgear/sg_inlines.h>
  30
  31 #include <stdio.h>    //    size_t
  32 #include <string>
  33
  34 #include <simgear/constants.h>
  35 #include <simgear/debug/logstream.hxx>
  36 #include <simgear/math/sg_geodesy.hxx>
  37 #include <simgear/misc/sg_path.hxx>
  38 #include <simgear/structure/commands.hxx>
  39
  40 #include <FDM/flight.hxx>
  41
  42 #include <Aircraft/controls.hxx>
  43 #include <Main/globals.hxx>
  44 #include <Main/fg_props.hxx>
  45
  46 #include "JSBSim.hxx"
  47 #include <FDM/JSBSim/FGFDMExec.h>
  48 #include <FDM/JSBSim/FGJSBBase.h>
  49 #include <FDM/JSBSim/initialization/FGInitialCondition.h>
  50 #include <FDM/JSBSim/initialization/FGTrim.h>
  51 #include <FDM/JSBSim/models/FGModel.h>
  52 #include <FDM/JSBSim/models/FGAircraft.h>
  53 #include <FDM/JSBSim/models/FGFCS.h>
  54 #include <FDM/JSBSim/models/FGPropagate.h>
  55 #include <FDM/JSBSim/models/FGAuxiliary.h>
  56 #include <FDM/JSBSim/models/FGInertial.h>
  57 #include <FDM/JSBSim/models/FGAtmosphere.h>
  58 #include <FDM/JSBSim/models/FGMassBalance.h>
  59 #include <FDM/JSBSim/models/FGAerodynamics.h>
  60 #include <FDM/JSBSim/models/FGLGear.h>
  61 #include <FDM/JSBSim/models/FGGroundReactions.h>
  62 #include <FDM/JSBSim/models/FGPropulsion.h>
  63 #include <FDM/JSBSim/models/FGAccelerations.h>
  64 #include <FDM/JSBSim/models/atmosphere/FGWinds.h>
  65 #include <FDM/JSBSim/models/propulsion/FGEngine.h>
  66 #include <FDM/JSBSim/models/propulsion/FGPiston.h>
  67 #include <FDM/JSBSim/models/propulsion/FGTurbine.h>
  68 #include <FDM/JSBSim/models/propulsion/FGTurboProp.h>
  69 #include <FDM/JSBSim/models/propulsion/FGRocket.h>
  70 #include <FDM/JSBSim/models/propulsion/FGElectric.h>
  71 #include <FDM/JSBSim/models/propulsion/FGNozzle.h>
  72 #include <FDM/JSBSim/models/propulsion/FGPropeller.h>
  73 #include <FDM/JSBSim/models/propulsion/FGRotor.h>
  74 #include <FDM/JSBSim/models/propulsion/FGTank.h>
  75 #include <FDM/JSBSim/input_output/FGPropertyManager.h>
  76 #include <FDM/JSBSim/input_output/FGGroundCallback.h>
  77
  78 using namespace JSBSim;
  79
  80 static inline double
  81 FMAX (double a, double b)
  82 {
  83   return a > b ? a : b;
  84 }
  85
  86 class FGFSGroundCallback : public FGGroundCallback {
  87 public:
  88   FGFSGroundCallback(FGJSBsim* ifc) : mInterface(ifc) {}
  89   virtual ~FGFSGroundCallback() {}
  90
  91   /** Get the altitude above sea level dependent on the location. */
  92   virtual double GetAltitude(const FGLocation& l) const {
  93     double pt[3] = { SG_FEET_TO_METER*l(FGJSBBase::eX),
  94                      SG_FEET_TO_METER*l(FGJSBBase::eY),
  95                      SG_FEET_TO_METER*l(FGJSBBase::eZ) };
  96     double lat, lon, alt;
  97     sgCartToGeod( pt, &lat, &lon, &alt);
  98     return alt * SG_METER_TO_FEET;
  99   }
 100
 101   /** Compute the altitude above ground. */
 102   virtual double GetAGLevel(double t, const FGLocation& l,
 103                             FGLocation& cont, FGColumnVector3& n,
 104                             FGColumnVector3& v, FGColumnVector3& w) const {
 105     double loc_cart[3] = { l(FGJSBBase::eX), l(FGJSBBase::eY), l(FGJSBBase::eZ) };
 106     double contact[3], normal[3], vel[3], angularVel[3], agl = 0;
 107     mInterface->get_agl_ft(t, loc_cart, SG_METER_TO_FEET*2, contact, normal,
 108                            vel, angularVel, &agl);
 109     n = FGColumnVector3( normal[0], normal[1], normal[2] );
 110     v = FGColumnVector3( vel[0], vel[1], vel[2] );
 111     w = FGColumnVector3( angularVel[0], angularVel[1], angularVel[2] );
 112     cont = FGColumnVector3( contact[0], contact[1], contact[2] );
 113     return agl;
 114   }
 115
 116   virtual double GetTerrainGeoCentRadius(double t, const FGLocation& l) const {
 117     double loc_cart[3] = { l(FGJSBBase::eX), l(FGJSBBase::eY), l(FGJSBBase::eZ) };
 118     double contact[3], normal[3], vel[3], angularVel[3], agl = 0;
 119     mInterface->get_agl_ft(t, loc_cart, SG_METER_TO_FEET*2, contact, normal,
 120                            vel, angularVel, &agl);
 121     return sqrt(contact[0]*contact[0]+contact[1]*contact[1]+contact[2]*contact[2]);
 122   }
 123
 124   virtual double GetSeaLevelRadius(const FGLocation& l) const {
 125     double seaLevelRadius, latGeoc;
 126
 127     sgGeodToGeoc(l.GetGeodLatitudeRad(), l.GetGeodAltitude(),
 128                  &seaLevelRadius, &latGeoc);
 129
 130     return seaLevelRadius * SG_METER_TO_FEET;
 131   }
 132
 133   virtual void SetTerrainGeoCentRadius(double radius) {}
 134   virtual void SetSeaLevelRadius(double radius) {}
 135 private:
 136   FGJSBsim* mInterface;
 137 };
 138
 139 // FG uses a squared normalized magnitude for turbulence
 140 // this lookup table maps fg's severity levels
 141 // none(0), light(1/3), moderate(2/3) and severe(3/3)
 142 // to the POE table indexes 0, 3, 4 and 7
 143 class FGTurbulenceSeverityTable : public FGTable {
 144 public:
 145   FGTurbulenceSeverityTable() : FGTable(4) {
 146     *this << (0.0/9.0) << 0.0;
 147     *this << (1.0/9.0) << 3.0;
 148     *this << (4.0/9.0) << 4.0;
 149     *this << (9.0/9.0) << 7.0;
 150   }
 151 };
 152
 153 /******************************************************************************/
 154 std::map<std::string,int> FGJSBsim::TURBULENCE_TYPE_NAMES;
 155
 156 static FGTurbulenceSeverityTable TurbulenceSeverityTable;
 157
 158 FGJSBsim::FGJSBsim( double dt )
 159   : FGInterface(dt), got_wire(false)
 160 {
 161     bool result;
 162     if( TURBULENCE_TYPE_NAMES.empty() ) {
 163         TURBULENCE_TYPE_NAMES["ttNone"]     = FGWinds::ttNone;
 164         TURBULENCE_TYPE_NAMES["ttStandard"] = FGWinds::ttStandard;
 165         TURBULENCE_TYPE_NAMES["ttCulp"]     = FGWinds::ttCulp;
 166         TURBULENCE_TYPE_NAMES["ttMilspec"]  = FGWinds::ttMilspec;
 167         TURBULENCE_TYPE_NAMES["ttTustin"]   = FGWinds::ttTustin;
 168     }
 169
 170     // Set up the debugging level
 171     // FIXME: this will not respond to
 172     // runtime changes
 173
 174                                 // if flight is excluded, don't bother
 175     if ((sglog().get_log_classes() & SG_FLIGHT) != 0) {
 176
 177                                 // do a rough-and-ready mapping to
 178                                 // the levels documented in FGFDMExec.h
 179         switch (sglog().get_log_priority()) {
 180         case SG_BULK:
 181             FGJSBBase::debug_lvl = 0x1f;
 182             break;
 183         case SG_DEBUG:
 184             FGJSBBase::debug_lvl = 0x0f;
 185         case SG_INFO:
 186             FGJSBBase::debug_lvl = 0x01;
 187             break;
 188         case SG_WARN:
 189         case SG_ALERT:
 190             FGJSBBase::debug_lvl = 0x00;
 191             break;
 192         }
 193     }
 194
 195     PropertyManager = new FGPropertyManager( (FGPropertyNode*)globals->get_props() );
 196     fdmex = new FGFDMExec( PropertyManager );
 197
 198     // Register ground callback.
 199     fdmex->SetGroundCallback( new FGFSGroundCallback(this) );
 200
 201     Atmosphere      = fdmex->GetAtmosphere();
 202     Winds           = fdmex->GetWinds();
 203     FCS             = fdmex->GetFCS();
 204     MassBalance     = fdmex->GetMassBalance();
 205     Propulsion      = fdmex->GetPropulsion();
 206     Aircraft        = fdmex->GetAircraft();
 207     Propagate       = fdmex->GetPropagate();
 208     Auxiliary       = fdmex->GetAuxiliary();
 209     Inertial        = fdmex->GetInertial();
 210     Aerodynamics    = fdmex->GetAerodynamics();
 211     GroundReactions = fdmex->GetGroundReactions();
 212     Accelerations   = fdmex->GetAccelerations();
 213
 214     fgic=fdmex->GetIC();
 215     needTrim=true;
 216
 217     SGPath aircraft_path( fgGetString("/sim/aircraft-dir") );
 218
 219     SGPath engine_path( fgGetString("/sim/aircraft-dir") );
 220     engine_path.append( "Engine" );
 221
 222     SGPath systems_path( fgGetString("/sim/aircraft-dir") );
 223     systems_path.append( "Systems" );
 224
 225 // deprecate sim-time-sec for simulation/sim-time-sec
 226 // remove alias with increased configuration file version number (2.1 or later)
 227     SGPropertyNode * node = fgGetNode("/fdm/jsbsim/simulation/sim-time-sec");
 228     fgGetNode("/fdm/jsbsim/sim-time-sec", true)->alias( node );
 229 // end of sim-time-sec deprecation patch
 230
 231     fdmex->Setdt( dt );
 232
 233     result = fdmex->LoadModel( aircraft_path.str(),
 234                                engine_path.str(),
 235                                systems_path.str(),
 236                                fgGetString("/sim/aero"), false );
 237
 238     if (result) {
 239       SG_LOG( SG_FLIGHT, SG_INFO, "  loaded aero.");
 240     } else {
 241       SG_LOG( SG_FLIGHT, SG_INFO,
 242               "  aero does not exist (you may have mis-typed the name).");
 243       throw(-1);
 244     }
 245
 246     SG_LOG( SG_FLIGHT, SG_INFO, "" );
 247     SG_LOG( SG_FLIGHT, SG_INFO, "" );
 248     SG_LOG( SG_FLIGHT, SG_INFO, "After loading aero definition file ..." );
 249
 250     int Neng = Propulsion->GetNumEngines();
 251     SG_LOG( SG_FLIGHT, SG_INFO, "num engines = " << Neng );
 252
 253     if ( GroundReactions->GetNumGearUnits() <= 0 ) {
 254         SG_LOG( SG_FLIGHT, SG_ALERT, "num gear units = "
 255                 << GroundReactions->GetNumGearUnits() );
 256         SG_LOG( SG_FLIGHT, SG_ALERT, "This is a very bad thing because with 0 gear units, the ground trimming");
 257         SG_LOG( SG_FLIGHT, SG_ALERT, "routine (coming up later in the code) will core dump.");
 258         SG_LOG( SG_FLIGHT, SG_ALERT, "Halting the sim now, and hoping a solution will present itself soon!");
 259         exit(-1);
 260     }
 261
 262     init_gear();
 263
 264     // Set initial fuel levels if provided.
 265     for (unsigned int i = 0; i < Propulsion->GetNumTanks(); i++) {
 266       double d;
 267       SGPropertyNode * node = fgGetNode("/consumables/fuel/tank", i, true);
 268       FGTank* tank = Propulsion->GetTank(i);
 269
 270       d = node->getNode( "density-ppg", true )->getDoubleValue();
 271       if( d > 0.0 ) {
 272         tank->SetDensity( d );
 273       } else {
 274         node->getNode( "density-ppg", true )->setDoubleValue( SG_MAX2<double>(tank->GetDensity(), 0.1) );
 275       }
 276
 277       d = node->getNode( "level-lbs", true )->getDoubleValue();
 278       if( d > 0.0 ) {
 279         tank->SetContents( d );
 280       } else {
 281         node->getNode( "level-lbs", true )->setDoubleValue( tank->GetContents() );
 282       }
 283       /* Capacity is read-only in FGTank and can't be overwritten from FlightGear */
 284       node->getNode("capacity-gal_us", true )->setDoubleValue( tank->GetCapacityGallons() );
 285     }
 286     Propulsion->SetFuelFreeze((fgGetNode("/sim/freeze/fuel",true))->getBoolValue());
 287
 288     fgSetDouble("/fdm/trim/pitch-trim", FCS->GetPitchTrimCmd());
 289     fgSetDouble("/fdm/trim/throttle",   FCS->GetThrottleCmd(0));
 290     fgSetDouble("/fdm/trim/aileron",    FCS->GetDaCmd());
 291     fgSetDouble("/fdm/trim/rudder",     FCS->GetDrCmd());
 292
 293     startup_trim = fgGetNode("/sim/presets/trim", true);
 294
 295     trimmed = fgGetNode("/fdm/trim/trimmed", true);
 296     trimmed->setBoolValue(false);
 297
 298     pitch_trim = fgGetNode("/fdm/trim/pitch-trim", true );
 299     throttle_trim = fgGetNode("/fdm/trim/throttle", true );
 300     aileron_trim = fgGetNode("/fdm/trim/aileron", true );
 301     rudder_trim = fgGetNode("/fdm/trim/rudder", true );
 302
 303     stall_warning = fgGetNode("/sim/alarms/stall-warning",true);
 304     stall_warning->setDoubleValue(0);
 305
 306
 307     flap_pos_pct=fgGetNode("/surface-positions/flap-pos-norm",true);
 308     elevator_pos_pct=fgGetNode("/surface-positions/elevator-pos-norm",true);
 309     left_aileron_pos_pct
 310         =fgGetNode("/surface-positions/left-aileron-pos-norm",true);
 311     right_aileron_pos_pct
 312         =fgGetNode("/surface-positions/right-aileron-pos-norm",true);
 313     rudder_pos_pct=fgGetNode("/surface-positions/rudder-pos-norm",true);
 314     speedbrake_pos_pct
 315         =fgGetNode("/surface-positions/speedbrake-pos-norm",true);
 316     spoilers_pos_pct=fgGetNode("/surface-positions/spoilers-pos-norm",true);
 317     tailhook_pos_pct=fgGetNode("/gear/tailhook/position-norm",true);
 318     wing_fold_pos_pct=fgGetNode("surface-positions/wing-fold-pos-norm",true);
 319
 320     elevator_pos_pct->setDoubleValue(0);
 321     left_aileron_pos_pct->setDoubleValue(0);
 322     right_aileron_pos_pct->setDoubleValue(0);
 323     rudder_pos_pct->setDoubleValue(0);
 324     flap_pos_pct->setDoubleValue(0);
 325     speedbrake_pos_pct->setDoubleValue(0);
 326     spoilers_pos_pct->setDoubleValue(0);
 327
 328     ab_brake_engaged = fgGetNode("/autopilot/autobrake/engaged", true);
 329     ab_brake_left_pct = fgGetNode("/autopilot/autobrake/brake-left-output", true);
 330     ab_brake_right_pct = fgGetNode("/autopilot/autobrake/brake-right-output", true);
 331
 332     altitude = fgGetNode("/position/altitude-ft");
 333     temperature = fgGetNode("/environment/temperature-degc",true);
 334     pressure = fgGetNode("/environment/pressure-inhg",true);
 335     pressureSL = fgGetNode("/environment/pressure-sea-level-inhg",true);
 336     ground_wind = fgGetNode("/environment/config/boundary/entry[0]/wind-speed-kt",true);
 337     turbulence_gain = fgGetNode("/environment/turbulence/magnitude-norm",true);
 338     turbulence_rate = fgGetNode("/environment/turbulence/rate-hz",true);
 339     turbulence_model = fgGetNode("/environment/params/jsbsim-turbulence-model",true);
 340
 341     wind_from_north= fgGetNode("/environment/wind-from-north-fps",true);
 342     wind_from_east = fgGetNode("/environment/wind-from-east-fps" ,true);
 343     wind_from_down = fgGetNode("/environment/wind-from-down-fps" ,true);
 344
 345     slaved = fgGetNode("/sim/slaved/enabled", true);
 346
 347     for (unsigned int i = 0; i < Propulsion->GetNumEngines(); i++) {
 348       SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 349       Propulsion->GetEngine(i)->GetThruster()->SetRPM(node->getDoubleValue("rpm") /
 350                      Propulsion->GetEngine(i)->GetThruster()->GetGearRatio());
 351     }
 352
 353     hook_root_struct = FGColumnVector3(
 354         fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-offset-x-in", 196),
 355         fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-offset-y-in", 0),
 356         fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-offset-z-in", -16));
 357     last_hook_tip[0] = 0; last_hook_tip[1] = 0; last_hook_tip[2] = 0;
 358     last_hook_root[0] = 0; last_hook_root[1] = 0; last_hook_root[2] = 0;
 359
 360     crashed = false;
 361 }
 362
 363 /******************************************************************************/
 364 FGJSBsim::~FGJSBsim(void)
 365 {
 366   delete fdmex;
 367   delete PropertyManager;
 368 }
 369
 370 /******************************************************************************/
 371
 372 // Initialize the JSBsim flight model, dt is the time increment for
 373 // each subsequent iteration through the EOM
 374
 375 void FGJSBsim::init()
 376 {
 377     SG_LOG( SG_FLIGHT, SG_INFO, "Starting and initializing JSBsim" );
 378
 379     // Explicitly call the superclass's
 380     // init method first.
 381
 382     if (fgGetBool("/environment/params/control-fdm-atmosphere")) {
 383       Atmosphere->SetTemperature(temperature->getDoubleValue(), get_Altitude(), FGAtmosphere::eCelsius);
 384       Atmosphere->SetPressureSL(FGAtmosphere::eInchesHg, pressureSL->getDoubleValue());
 385       // initialize to no turbulence, these values get set in the update loop
 386       Winds->SetTurbType(FGWinds::ttNone);
 387       Winds->SetTurbGain(0.0);
 388       Winds->SetTurbRate(0.0);
 389       Winds->SetWindspeed20ft(0.0);
 390       Winds->SetProbabilityOfExceedence(0.0);
 391     }
 392
 393     fgic->SetWindNEDFpsIC( -wind_from_north->getDoubleValue(),
 394                            -wind_from_east->getDoubleValue(),
 395                            -wind_from_down->getDoubleValue() );
 396
 397     SG_LOG(SG_FLIGHT,SG_INFO,"T,p,rho: " << Atmosphere->GetTemperature()
 398      << ", " << Atmosphere->GetPressure()
 399      << ", " << Atmosphere->GetDensity() );
 400
 401     FCS->SetDfPos( ofNorm, globals->get_controls()->get_flaps() );
 402
 403     needTrim = startup_trim->getBoolValue();
 404     common_init();
 405
 406     copy_to_JSBsim();
 407     fdmex->RunIC();     //loop JSBSim once w/o integrating
 408     if (fgGetBool("/sim/presets/running")) {
 409       Propulsion->InitRunning(-1);
 410       for (unsigned int i = 0; i < Propulsion->GetNumEngines(); i++) {
 411         FGPiston* eng = (FGPiston*)Propulsion->GetEngine(i);
 412         globals->get_controls()->set_magnetos(i, eng->GetMagnetos());
 413         globals->get_controls()->set_mixture(i, FCS->GetMixtureCmd(i));
 414       }
 415     }
 416
 417     if ( needTrim ) {
 418       FGLocation cart(fgic->GetLongitudeRadIC(), fgic->GetLatitudeRadIC(),
 419                       get_Sea_level_radius() + fgic->GetAltitudeASLFtIC());
 420       double cart_pos[3], contact[3], d[3], vel[3], agl;
 421       update_ground_cache(cart, cart_pos, 0.01);
 422
 423       get_agl_ft(fdmex->GetSimTime(), cart_pos, SG_METER_TO_FEET*2, contact,
 424                  d, vel, d, &agl);
 425       double terrain_alt = sqrt(contact[0]*contact[0] + contact[1]*contact[1]
 426            + contact[2]*contact[2]) - get_Sea_level_radius();
 427
 428       SG_LOG(SG_FLIGHT, SG_INFO, "Ready to trim, terrain elevation is: "
 429                                  << terrain_alt * SG_METER_TO_FEET );
 430
 431       if (fgGetBool("/sim/presets/onground")) {
 432         FGColumnVector3 gndVelNED = cart.GetTec2l()
 433                                   * FGColumnVector3(vel[0], vel[1], vel[2]);
 434         fgic->SetVNorthFpsIC(gndVelNED(1));
 435         fgic->SetVEastFpsIC(gndVelNED(2));
 436         fgic->SetVDownFpsIC(gndVelNED(3));
 437       }
 438       fgic->SetTerrainElevationFtIC( terrain_alt );
 439       do_trim();
 440       needTrim = false;
 441     }
 442
 443     copy_from_JSBsim(); //update the bus
 444
 445     SG_LOG( SG_FLIGHT, SG_INFO, "  Initialized JSBSim with:" );
 446
 447     switch(fgic->GetSpeedSet()) {
 448     case setned:
 449         SG_LOG(SG_FLIGHT,SG_INFO, "  Vn,Ve,Vd= "
 450                << Propagate->GetVel(FGJSBBase::eNorth) << ", "
 451                << Propagate->GetVel(FGJSBBase::eEast) << ", "
 452                << Propagate->GetVel(FGJSBBase::eDown) << " ft/s");
 453     break;
 454     case setuvw:
 455         SG_LOG(SG_FLIGHT,SG_INFO, "  U,V,W= "
 456                << Propagate->GetUVW(1) << ", "
 457                << Propagate->GetUVW(2) << ", "
 458                << Propagate->GetUVW(3) << " ft/s");
 459     break;
 460     case setmach:
 461         SG_LOG(SG_FLIGHT,SG_INFO, "  Mach: "
 462                << Auxiliary->GetMach() );
 463     break;
 464     case setvc:
 465     default:
 466         SG_LOG(SG_FLIGHT,SG_INFO, "  Indicated Airspeed: "
 467                << Auxiliary->GetVcalibratedKTS() << " knots" );
 468     break;
 469     }
 470
 471     stall_warning->setDoubleValue(0);
 472
 473     SG_LOG( SG_FLIGHT, SG_INFO, "  Bank Angle: "
 474             << Propagate->GetEuler(FGJSBBase::ePhi)*RADTODEG << " deg" );
 475     SG_LOG( SG_FLIGHT, SG_INFO, "  Pitch Angle: "
 476             << Propagate->GetEuler(FGJSBBase::eTht)*RADTODEG << " deg" );
 477     SG_LOG( SG_FLIGHT, SG_INFO, "  True Heading: "
 478             << Propagate->GetEuler(FGJSBBase::ePsi)*RADTODEG << " deg" );
 479     SG_LOG( SG_FLIGHT, SG_INFO, "  Latitude: "
 480             << Propagate->GetLocation().GetLatitudeDeg() << " deg" );
 481     SG_LOG( SG_FLIGHT, SG_INFO, "  Longitude: "
 482             << Propagate->GetLocation().GetLongitudeDeg() << " deg" );
 483     SG_LOG( SG_FLIGHT, SG_INFO, "  Altitude: "
 484             << Propagate->GetAltitudeASL() << " feet" );
 485     SG_LOG( SG_FLIGHT, SG_INFO, "  loaded initial conditions" );
 486
 487     SG_LOG( SG_FLIGHT, SG_INFO, "  set dt" );
 488
 489     SG_LOG( SG_FLIGHT, SG_INFO, "Finished initializing JSBSim" );
 490
 491     SG_LOG( SG_FLIGHT, SG_INFO, "FGControls::get_gear_down()= " <<
 492                                   globals->get_controls()->get_gear_down() );
 493 }
 494
 495 /******************************************************************************/
 496
 497 void FGJSBsim::unbind()
 498 {
 499   fdmex->Unbind();
 500   FGInterface::unbind();
 501 }
 502
 503 /******************************************************************************/
 504
 505 // Run an iteration of the EOM (equations of motion)
 506
 507 void FGJSBsim::update( double dt )
 508 {
 509     if(crashed) {
 510       if(!fgGetBool("/sim/crashed"))
 511         fgSetBool("/sim/crashed", true);
 512       return;
 513     }
 514
 515     if (is_suspended())
 516       return;
 517
 518     int multiloop = _calc_multiloop(dt);
 519     FGLocation cart = Auxiliary->GetLocationVRP();
 520     double cart_pos[3];
 521
 522     update_ground_cache(cart, cart_pos, dt);
 523
 524     copy_to_JSBsim();
 525
 526     trimmed->setBoolValue(false);
 527
 528     for ( int i=0; i < multiloop; i++ ) {
 529       fdmex->Run();
 530       update_external_forces(fdmex->GetSimTime() + i * fdmex->GetDeltaT());
 531     }
 532
 533     FGJSBBase::Message* msg;
 534     while ((msg = fdmex->ProcessNextMessage()) != NULL) {
 535 //      msg = fdmex->ProcessNextMessage();
 536       switch (msg->type) {
 537       case FGJSBBase::Message::eText:
 538         if (msg->text == "Crash Detected: Simulation FREEZE.")
 539           crashed = true;
 540         SG_LOG( SG_FLIGHT, SG_INFO, msg->messageId << ": " << msg->text );
 541         break;
 542       case FGJSBBase::Message::eBool:
 543         SG_LOG( SG_FLIGHT, SG_INFO, msg->messageId << ": " << msg->text << " " << msg->bVal );
 544         break;
 545       case FGJSBBase::Message::eInteger:
 546         SG_LOG( SG_FLIGHT, SG_INFO, msg->messageId << ": " << msg->text << " " << msg->iVal );
 547         break;
 548       case FGJSBBase::Message::eDouble:
 549         SG_LOG( SG_FLIGHT, SG_INFO, msg->messageId << ": " << msg->text << " " << msg->dVal );
 550         break;
 551       default:
 552         SG_LOG( SG_FLIGHT, SG_INFO, "Unrecognized message type." );
 553         break;
 554       }
 555     }
 556
 557     // translate JSBsim back to FG structure so that the
 558     // autopilot (and the rest of the sim can use the updated values
 559     copy_from_JSBsim();
 560 }
 561
 562 /******************************************************************************/
 563
 564 void FGJSBsim::suspend()
 565 {
 566   fdmex->Hold();
 567   SGSubsystem::suspend();
 568 }
 569
 570 /******************************************************************************/
 571
 572 void FGJSBsim::resume()
 573 {
 574   fdmex->Resume();
 575   SGSubsystem::resume();
 576 }
 577
 578 /******************************************************************************/
 579
 580 // Convert from the FGInterface struct to the JSBsim generic_ struct
 581
 582 bool FGJSBsim::copy_to_JSBsim()
 583 {
 584     unsigned int i;
 585
 586     // copy control positions into the JSBsim structure
 587
 588     FCS->SetDaCmd( globals->get_controls()->get_aileron());
 589     FCS->SetRollTrimCmd( globals->get_controls()->get_aileron_trim() );
 590     FCS->SetDeCmd( globals->get_controls()->get_elevator());
 591     FCS->SetPitchTrimCmd( globals->get_controls()->get_elevator_trim() );
 592     FCS->SetDrCmd( -globals->get_controls()->get_rudder() );
 593     FCS->SetYawTrimCmd( -globals->get_controls()->get_rudder_trim() );
 594     FCS->SetDsCmd( globals->get_controls()->get_rudder() );
 595     FCS->SetDfCmd( globals->get_controls()->get_flaps() );
 596     FCS->SetDsbCmd( globals->get_controls()->get_speedbrake() );
 597     FCS->SetDspCmd( globals->get_controls()->get_spoilers() );
 598
 599         // Parking brake sets minimum braking
 600         // level for mains.
 601     double parking_brake = globals->get_controls()->get_brake_parking();
 602     double left_brake = globals->get_controls()->get_brake_left();
 603     double right_brake = globals->get_controls()->get_brake_right();
 604
 605     if (ab_brake_engaged->getBoolValue()) {
 606       left_brake = ab_brake_left_pct->getDoubleValue();
 607       right_brake = ab_brake_right_pct->getDoubleValue();
 608     }
 609
 610     FCS->SetLBrake(FMAX(left_brake, parking_brake));
 611     FCS->SetRBrake(FMAX(right_brake, parking_brake));
 612
 613
 614     FCS->SetCBrake( 0.0 );
 615     // FCS->SetCBrake( globals->get_controls()->get_brake(2) );
 616
 617     FCS->SetGearCmd( globals->get_controls()->get_gear_down());
 618     for (i = 0; i < Propulsion->GetNumEngines(); i++) {
 619       SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 620
 621       FCS->SetThrottleCmd(i, globals->get_controls()->get_throttle(i));
 622       FCS->SetMixtureCmd(i, globals->get_controls()->get_mixture(i));
 623       FCS->SetPropAdvanceCmd(i, globals->get_controls()->get_prop_advance(i));
 624       FCS->SetFeatherCmd(i, globals->get_controls()->get_feather(i));
 625
 626       switch (Propulsion->GetEngine(i)->GetType()) {
 627       case FGEngine::etPiston:
 628         { // FGPiston code block
 629         FGPiston* eng = (FGPiston*)Propulsion->GetEngine(i);
 630         eng->SetMagnetos( globals->get_controls()->get_magnetos(i) );
 631         break;
 632         } // end FGPiston code block
 633       case FGEngine::etTurbine:
 634         { // FGTurbine code block
 635         FGTurbine* eng = (FGTurbine*)Propulsion->GetEngine(i);
 636         eng->SetAugmentation( globals->get_controls()->get_augmentation(i) );
 637         eng->SetReverse( globals->get_controls()->get_reverser(i) );
 638         //eng->SetInjection( globals->get_controls()->get_water_injection(i) );
 639         eng->SetCutoff( globals->get_controls()->get_cutoff(i) );
 640         eng->SetIgnition( globals->get_controls()->get_ignition(i) );
 641         break;
 642         } // end FGTurbine code block
 643       case FGEngine::etRocket:
 644         { // FGRocket code block
 645 //        FGRocket* eng = (FGRocket*)Propulsion->GetEngine(i);
 646         break;
 647         } // end FGRocket code block
 648       case FGEngine::etTurboprop:
 649         { // FGTurboProp code block
 650         FGTurboProp* eng = (FGTurboProp*)Propulsion->GetEngine(i);
 651         eng->SetReverse( globals->get_controls()->get_reverser(i) );
 652         eng->SetCutoff( globals->get_controls()->get_cutoff(i) );
 653         eng->SetIgnition( globals->get_controls()->get_ignition(i) );
 654
 655         eng->SetGeneratorPower( globals->get_controls()->get_generator_breaker(i) );
 656         eng->SetCondition( globals->get_controls()->get_condition(i) );
 657         break;
 658         } // end FGTurboProp code block
 659       default:
 660         break;
 661       }
 662
 663       { // FGEngine code block
 664       FGEngine* eng = Propulsion->GetEngine(i);
 665
 666       eng->SetStarter( globals->get_controls()->get_starter(i) );
 667       eng->SetRunning( node->getBoolValue("running") );
 668       } // end FGEngine code block
 669     }
 670
 671     Atmosphere->SetTemperature(temperature->getDoubleValue(), get_Altitude(), FGAtmosphere::eCelsius);
 672     Atmosphere->SetPressureSL(FGAtmosphere::eInchesHg, pressureSL->getDoubleValue());
 673
 674     Winds->SetTurbType((FGWinds::tType)TURBULENCE_TYPE_NAMES[turbulence_model->getStringValue()]);
 675     switch( Winds->GetTurbType() ) {
 676         case FGWinds::ttStandard:
 677         case FGWinds::ttCulp: {
 678             double tmp = turbulence_gain->getDoubleValue();
 679             Winds->SetTurbGain(tmp * tmp * 100.0);
 680             Winds->SetTurbRate(turbulence_rate->getDoubleValue());
 681             break;
 682         }
 683         case FGWinds::ttMilspec:
 684         case FGWinds::ttTustin: {
 685             // milspec turbulence: 3=light, 4=moderate, 6=severe turbulence
 686             // turbulence_gain normalized: 0: none, 1/3: light, 2/3: moderate, 3/3: severe
 687             double tmp = turbulence_gain->getDoubleValue();
 688             Winds->SetProbabilityOfExceedence(
 689               SGMiscd::roundToInt(TurbulenceSeverityTable.GetValue( tmp ) )
 690             );
 691             Winds->SetWindspeed20ft(ground_wind->getDoubleValue());
 692             break;
 693         }
 694
 695         default:
 696             break;
 697     }
 698
 699     Winds->SetWindNED( -wind_from_north->getDoubleValue(),
 700                        -wind_from_east->getDoubleValue(),
 701                        -wind_from_down->getDoubleValue() );
 702 //    SG_LOG(SG_FLIGHT,SG_INFO, "Wind NED: "
 703 //                  << get_V_north_airmass() << ", "
 704 //                  << get_V_east_airmass()  << ", "
 705 //                  << get_V_down_airmass() );
 706
 707     for (i = 0; i < Propulsion->GetNumTanks(); i++) {
 708       SGPropertyNode * node = fgGetNode("/consumables/fuel/tank", i, true);
 709       FGTank * tank = Propulsion->GetTank(i);
 710       double fuelDensity = node->getDoubleValue("density-ppg");
 711
 712       if (fuelDensity < 0.1)
 713         fuelDensity = 6.0; // Use average fuel value
 714
 715       tank->SetDensity(fuelDensity);
 716       tank->SetContents(node->getDoubleValue("level-lbs"));
 717     }
 718
 719     Propulsion->SetFuelFreeze((fgGetNode("/sim/freeze/fuel",true))->getBoolValue());
 720     fdmex->SetChild(slaved->getBoolValue());
 721
 722     return true;
 723 }
 724
 725 /******************************************************************************/
 726
 727 // Convert from the JSBsim generic_ struct to the FGInterface struct
 728
 729 bool FGJSBsim::copy_from_JSBsim()
 730 {
 731     unsigned int i, j;
 732 /*
 733     _set_Inertias( MassBalance->GetMass(),
 734                    MassBalance->GetIxx(),
 735                    MassBalance->GetIyy(),
 736                    MassBalance->GetIzz(),
 737                    MassBalance->GetIxz() );
 738 */
 739     _set_CG_Position( MassBalance->GetXYZcg(1),
 740                       MassBalance->GetXYZcg(2),
 741                       MassBalance->GetXYZcg(3) );
 742
 743     _set_Accels_Body( Accelerations->GetBodyAccel(1),
 744                       Accelerations->GetBodyAccel(2),
 745                       Accelerations->GetBodyAccel(3) );
 746
 747     _set_Accels_CG_Body_N ( Auxiliary->GetNcg(1),
 748                             Auxiliary->GetNcg(2),
 749                             Auxiliary->GetNcg(3) );
 750
 751     _set_Accels_Pilot_Body( Auxiliary->GetPilotAccel(1),
 752                             Auxiliary->GetPilotAccel(2),
 753                             Auxiliary->GetPilotAccel(3) );
 754
 755     _set_Nlf( Auxiliary->GetNlf() );
 756
 757     // Velocities
 758
 759     _set_Velocities_Local( Propagate->GetVel(FGJSBBase::eNorth),
 760                            Propagate->GetVel(FGJSBBase::eEast),
 761                            Propagate->GetVel(FGJSBBase::eDown) );
 762
 763     _set_Velocities_Body( Propagate->GetUVW(1),
 764                           Propagate->GetUVW(2),
 765                           Propagate->GetUVW(3) );
 766
 767     // Make the HUD work ...
 768     _set_Velocities_Ground( Propagate->GetVel(FGJSBBase::eNorth),
 769                             Propagate->GetVel(FGJSBBase::eEast),
 770                             -Propagate->GetVel(FGJSBBase::eDown) );
 771
 772     _set_V_rel_wind( Auxiliary->GetVt() );
 773
 774     _set_V_equiv_kts( Auxiliary->GetVequivalentKTS() );
 775
 776     _set_V_calibrated_kts( Auxiliary->GetVcalibratedKTS() );
 777
 778     _set_V_ground_speed( Auxiliary->GetVground() );
 779
 780     _set_Omega_Body( Propagate->GetPQR(FGJSBBase::eP),
 781                      Propagate->GetPQR(FGJSBBase::eQ),
 782                      Propagate->GetPQR(FGJSBBase::eR) );
 783
 784     _set_Euler_Rates( Auxiliary->GetEulerRates(FGJSBBase::ePhi),
 785                       Auxiliary->GetEulerRates(FGJSBBase::eTht),
 786                       Auxiliary->GetEulerRates(FGJSBBase::ePsi) );
 787
 788     _set_Mach_number( Auxiliary->GetMach() );
 789
 790     // Positions of Visual Reference Point
 791     FGLocation l = Auxiliary->GetLocationVRP();
 792     _updatePosition(SGGeoc::fromRadFt( l.GetLongitude(), l.GetLatitude(),
 793                                        l.GetRadius() ));
 794
 795     _set_Altitude_AGL( Propagate->GetDistanceAGL() );
 796     {
 797       double loc_cart[3] = { l(FGJSBBase::eX), l(FGJSBBase::eY), l(FGJSBBase::eZ) };
 798       double contact[3], d[3], sd, t;
 799       is_valid_m(&t, d, &sd);
 800       get_agl_ft(t, loc_cart, SG_METER_TO_FEET*2, contact, d, d, d, &sd);
 801       double rwrad
 802         = FGColumnVector3( contact[0], contact[1], contact[2] ).Magnitude();
 803       _set_Runway_altitude( rwrad - get_Sea_level_radius() );
 804     }
 805
 806     _set_Euler_Angles( Propagate->GetEuler(FGJSBBase::ePhi),
 807                        Propagate->GetEuler(FGJSBBase::eTht),
 808                        Propagate->GetEuler(FGJSBBase::ePsi) );
 809
 810     _set_Alpha( Auxiliary->Getalpha() );
 811     _set_Beta( Auxiliary->Getbeta() );
 812
 813
 814     _set_Gamma_vert_rad( Auxiliary->GetGamma() );
 815
 816     _set_Earth_position_angle( Propagate->GetEarthPositionAngle() );
 817
 818     _set_Climb_Rate( Propagate->Gethdot() );
 819
 820     const FGMatrix33& Tl2b = Propagate->GetTl2b();
 821     for ( i = 1; i <= 3; i++ ) {
 822         for ( j = 1; j <= 3; j++ ) {
 823             _set_T_Local_to_Body( i, j, Tl2b(i,j) );
 824         }
 825     }
 826
 827     // Copy the engine values from JSBSim.
 828     for ( i=0; i < Propulsion->GetNumEngines(); i++ ) {
 829       SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 830       SGPropertyNode * tnode = node->getChild("thruster", 0, true);
 831       FGThruster * thruster = Propulsion->GetEngine(i)->GetThruster();
 832
 833       switch (Propulsion->GetEngine(i)->GetType()) {
 834       case FGEngine::etPiston:
 835         { // FGPiston code block
 836         FGPiston* eng = (FGPiston*)Propulsion->GetEngine(i);
 837         node->setDoubleValue("egt-degf", eng->getExhaustGasTemp_degF());
 838         node->setDoubleValue("oil-temperature-degf", eng->getOilTemp_degF());
 839         node->setDoubleValue("oil-pressure-psi", eng->getOilPressure_psi());
 840         node->setDoubleValue("mp-osi", eng->getManifoldPressure_inHg());
 841         // NOTE: mp-osi is not in ounces per square inch.
 842         // This error is left for reasons of backwards compatibility with
 843         // existing FlightGear sound and instrument configurations.
 844         node->setDoubleValue("mp-inhg", eng->getManifoldPressure_inHg());
 845         node->setDoubleValue("cht-degf", eng->getCylinderHeadTemp_degF());
 846         node->setDoubleValue("rpm", eng->getRPM());
 847         } // end FGPiston code block
 848         break;
 849       case FGEngine::etRocket:
 850         { // FGRocket code block
 851 //        FGRocket* eng = (FGRocket*)Propulsion->GetEngine(i);
 852         } // end FGRocket code block
 853         break;
 854       case FGEngine::etTurbine:
 855         { // FGTurbine code block
 856         FGTurbine* eng = (FGTurbine*)Propulsion->GetEngine(i);
 857         node->setDoubleValue("n1", eng->GetN1());
 858         node->setDoubleValue("n2", eng->GetN2());
 859         node->setDoubleValue("egt-degf", 32 + eng->GetEGT()*9/5);
 860         node->setBoolValue("augmentation", eng->GetAugmentation());
 861         node->setBoolValue("water-injection", eng->GetInjection());
 862         node->setBoolValue("ignition", eng->GetIgnition() != 0);
 863         node->setDoubleValue("nozzle-pos-norm", eng->GetNozzle());
 864         node->setDoubleValue("inlet-pos-norm", eng->GetInlet());
 865         node->setDoubleValue("oil-pressure-psi", eng->getOilPressure_psi());
 866         node->setBoolValue("reversed", eng->GetReversed());
 867         node->setBoolValue("cutoff", eng->GetCutoff());
 868         node->setDoubleValue("epr", eng->GetEPR());
 869         globals->get_controls()->set_reverser(i, eng->GetReversed() );
 870         globals->get_controls()->set_cutoff(i, eng->GetCutoff() );
 871         globals->get_controls()->set_water_injection(i, eng->GetInjection() );
 872         globals->get_controls()->set_augmentation(i, eng->GetAugmentation() );
 873         } // end FGTurbine code block
 874         break;
 875       case FGEngine::etTurboprop:
 876         { // FGTurboProp code block
 877         FGTurboProp* eng = (FGTurboProp*)Propulsion->GetEngine(i);
 878         node->setDoubleValue("n1", eng->GetN1());
 879         //node->setDoubleValue("n2", eng->GetN2());
 880         node->setDoubleValue("itt_degf", 32 + eng->GetITT()*9/5);
 881         node->setBoolValue("ignition", eng->GetIgnition() != 0);
 882         node->setDoubleValue("nozzle-pos-norm", eng->GetNozzle());
 883         node->setDoubleValue("inlet-pos-norm", eng->GetInlet());
 884         node->setDoubleValue("oil-pressure-psi", eng->getOilPressure_psi());
 885         node->setBoolValue("reversed", eng->GetReversed());
 886         node->setBoolValue("cutoff", eng->GetCutoff());
 887         node->setBoolValue("starting", eng->GetEngStarting());
 888         node->setBoolValue("generator-power", eng->GetGeneratorPower());
 889         node->setBoolValue("damaged", eng->GetCondition() != 0);
 890         node->setBoolValue("ielu-intervent", eng->GetIeluIntervent());
 891         node->setDoubleValue("oil-temperature-degf", eng->getOilTemp_degF());
 892 //        node->setBoolValue("onfire", eng->GetFire());
 893         globals->get_controls()->set_reverser(i, eng->GetReversed() );
 894         globals->get_controls()->set_cutoff(i, eng->GetCutoff() );
 895         } // end FGTurboProp code block
 896         break;
 897       case FGEngine::etElectric:
 898         { // FGElectric code block
 899         FGElectric* eng = (FGElectric*)Propulsion->GetEngine(i);
 900         node->setDoubleValue("rpm", eng->getRPM());
 901         } // end FGElectric code block
 902         break;
 903       case FGEngine::etUnknown:
 904         break;
 905       }
 906
 907       { // FGEngine code block
 908       FGEngine* eng = Propulsion->GetEngine(i);
 909       node->setDoubleValue("fuel-flow-gph", eng->getFuelFlow_gph());
 910       node->setDoubleValue("thrust_lb", thruster->GetThrust());
 911       node->setDoubleValue("fuel-flow_pph", eng->getFuelFlow_pph());
 912       node->setBoolValue("running", eng->GetRunning());
 913       node->setBoolValue("starter", eng->GetStarter());
 914       node->setBoolValue("cranking", eng->GetCranking());
 915       globals->get_controls()->set_starter(i, eng->GetStarter() );
 916       } // end FGEngine code block
 917
 918       switch (thruster->GetType()) {
 919       case FGThruster::ttNozzle:
 920         { // FGNozzle code block
 921 //        FGNozzle* noz = (FGNozzle*)thruster;
 922         } // end FGNozzle code block
 923         break;
 924       case FGThruster::ttPropeller:
 925         { // FGPropeller code block
 926         FGPropeller* prop = (FGPropeller*)thruster;
 927         tnode->setDoubleValue("rpm", thruster->GetRPM());
 928         tnode->setDoubleValue("pitch", prop->GetPitch());
 929         tnode->setDoubleValue("torque", prop->GetTorque());
 930         tnode->setBoolValue("feathered", prop->GetFeather());
 931         } // end FGPropeller code block
 932         break;
 933       case FGThruster::ttRotor:
 934         { // FGRotor code block
 935 //        FGRotor* rotor = (FGRotor*)thruster;
 936         } // end FGRotor code block
 937         break;
 938       case FGThruster::ttDirect:
 939         { // Direct code block
 940         } // end Direct code block
 941         break;
 942       }
 943
 944     }
 945
 946     // Copy the fuel levels from JSBSim if fuel
 947     // freeze not enabled.
 948     if ( ! Propulsion->GetFuelFreeze() ) {
 949       for (i = 0; i < Propulsion->GetNumTanks(); i++) {
 950         SGPropertyNode * node = fgGetNode("/consumables/fuel/tank", i, true);
 951         FGTank* tank = Propulsion->GetTank(i);
 952         double contents = tank->GetContents();
 953         double temp = tank->GetTemperature_degC();
 954         double fuelDensity = tank->GetDensity();
 955
 956         if (fuelDensity < 0.1)
 957           fuelDensity = 6.0; // Use average fuel value
 958
 959         node->setDoubleValue("density-ppg" , fuelDensity);
 960         node->setDoubleValue("level-lbs", contents);
 961         if (temp != -9999.0) node->setDoubleValue("temperature_degC", temp);
 962       }
 963     }
 964
 965     update_gear();
 966
 967     stall_warning->setDoubleValue( Aerodynamics->GetStallWarn() );
 968
 969     elevator_pos_pct->setDoubleValue( FCS->GetDePos(ofNorm) );
 970     left_aileron_pos_pct->setDoubleValue( FCS->GetDaLPos(ofNorm) );
 971     right_aileron_pos_pct->setDoubleValue( FCS->GetDaRPos(ofNorm) );
 972     rudder_pos_pct->setDoubleValue( -1*FCS->GetDrPos(ofNorm) );
 973     flap_pos_pct->setDoubleValue( FCS->GetDfPos(ofNorm) );
 974     speedbrake_pos_pct->setDoubleValue( FCS->GetDsbPos(ofNorm) );
 975     spoilers_pos_pct->setDoubleValue( FCS->GetDspPos(ofNorm) );
 976     tailhook_pos_pct->setDoubleValue( FCS->GetTailhookPos() );
 977     wing_fold_pos_pct->setDoubleValue( FCS->GetWingFoldPos() );
 978
 979     // force a sim crashed if crashed (altitude AGL < 0)
 980     if (get_Altitude_AGL() < -100.0) {
 981          fdmex->SuspendIntegration();
 982          crashed = true;
 983     }
 984
 985     return true;
 986 }
 987
 988
 989 bool FGJSBsim::ToggleDataLogging(void)
 990 {
 991   // ToDo: handle this properly
 992   fdmex->DisableOutput();
 993   return false;
 994 }
 995
 996
 997 bool FGJSBsim::ToggleDataLogging(bool state)
 998 {
 999     if (state) {
1000       fdmex->EnableOutput();
1001       return true;
1002     } else {
1003       fdmex->DisableOutput();
1004       return false;
1005     }
1006 }
1007
1008
1009 //Positions
1010 void FGJSBsim::set_Latitude(double lat)
1011 {
1012   double alt = altitude->getDoubleValue();
1013   double sea_level_radius_meters, lat_geoc;
1014
1015   if ( alt < -9990 ) alt = 0.0;
1016
1017   SG_LOG(SG_FLIGHT,SG_INFO,"FGJSBsim::set_Latitude: " << lat );
1018   SG_LOG(SG_FLIGHT,SG_INFO," cur alt (ft) =  " << alt );
1019
1020   sgGeodToGeoc( lat, alt * SG_FEET_TO_METER,
1021                     &sea_level_radius_meters, &lat_geoc );
1022
1023   double sea_level_radius_ft = sea_level_radius_meters * SG_METER_TO_FEET;
1024   _set_Sea_level_radius( sea_level_radius_ft );
1025
1026   if (needTrim) {
1027     fgic->SetSeaLevelRadiusFtIC( sea_level_radius_ft );
1028     fgic->SetLatitudeRadIC( lat_geoc );
1029   }
1030   else
1031     Propagate->SetLatitude(lat_geoc);
1032
1033   FGInterface::set_Latitude(lat);
1034 }
1035
1036
1037 void FGJSBsim::set_Longitude(double lon)
1038 {
1039   SG_LOG(SG_FLIGHT,SG_INFO,"FGJSBsim::set_Longitude: " << lon );
1040
1041   if (needTrim)
1042     fgic->SetLongitudeRadIC(lon);
1043   else
1044     Propagate->SetLongitude(lon);
1045
1046   FGInterface::set_Longitude(lon);
1047 }
1048
1049 // Sets the altitude above sea level.
1050 void FGJSBsim::set_Altitude(double alt)
1051 {
1052   SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Altitude: " << alt );
1053
1054   if (needTrim)
1055     fgic->SetAltitudeASLFtIC(alt);
1056   else
1057     Propagate->SetAltitudeASL(alt);
1058
1059   FGInterface::set_Altitude(alt);
1060 }
1061
1062 void FGJSBsim::set_V_calibrated_kts(double vc)
1063 {
1064     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_V_calibrated_kts: " <<  vc );
1065
1066   if (needTrim)
1067     fgic->SetVcalibratedKtsIC(vc);
1068   else {
1069     double p=pressure->getDoubleValue();
1070     double psl=fdmex->GetAtmosphere()->GetPressureSL();
1071     double rhosl=fdmex->GetAtmosphere()->GetDensitySL();
1072     double mach = FGJSBBase::MachFromVcalibrated(vc, p, psl, rhosl);
1073     double temp = 1.8*(temperature->getDoubleValue()+273.15);
1074     double soundSpeed = sqrt(1.4*1716.0*temp);
1075     FGColumnVector3 vUVW = Propagate->GetUVW();
1076     vUVW.Normalize();
1077     vUVW *= mach * soundSpeed;
1078     Propagate->SetUVW(1, vUVW(1));
1079     Propagate->SetUVW(2, vUVW(2));
1080     Propagate->SetUVW(3, vUVW(3));
1081   }
1082
1083   FGInterface::set_V_calibrated_kts(vc);
1084 }
1085
1086 void FGJSBsim::set_Mach_number(double mach)
1087 {
1088   SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Mach_number: " <<  mach );
1089
1090   if (needTrim)
1091     fgic->SetMachIC(mach);
1092   else {
1093     double temp = 1.8*(temperature->getDoubleValue()+273.15);
1094     double soundSpeed = sqrt(1.4*1716.0*temp);
1095     FGColumnVector3 vUVW = Propagate->GetUVW();
1096     vUVW.Normalize();
1097     vUVW *= mach * soundSpeed;
1098     Propagate->SetUVW(1, vUVW(1));
1099     Propagate->SetUVW(2, vUVW(2));
1100     Propagate->SetUVW(3, vUVW(3));
1101   }
1102
1103   FGInterface::set_Mach_number(mach);
1104 }
1105
1106 void FGJSBsim::set_Velocities_Local( double north, double east, double down )
1107 {
1108   SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Velocities_Local: "
1109      << north << ", " <<  east << ", " << down );
1110
1111   if (needTrim) {
1112     fgic->SetVNorthFpsIC(north);
1113     fgic->SetVEastFpsIC(east);
1114     fgic->SetVDownFpsIC(down);
1115   }
1116   else {
1117     FGColumnVector3 vNED(north, east, down);
1118     FGColumnVector3 vUVW = Propagate->GetTl2b() * vNED;
1119     Propagate->SetUVW(1, vUVW(1));
1120     Propagate->SetUVW(2, vUVW(2));
1121     Propagate->SetUVW(3, vUVW(3));
1122   }
1123
1124   FGInterface::set_Velocities_Local(north, east, down);
1125 }
1126
1127 void FGJSBsim::set_Velocities_Body( double u, double v, double w)
1128 {
1129   SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Velocities_Body: "
1130      << u << ", " <<  v << ", " <<  w );
1131
1132   if (needTrim) {
1133     fgic->SetUBodyFpsIC(u);
1134     fgic->SetVBodyFpsIC(v);
1135     fgic->SetWBodyFpsIC(w);
1136   }
1137   else {
1138     Propagate->SetUVW(1, u);
1139     Propagate->SetUVW(2, v);
1140     Propagate->SetUVW(3, w);
1141   }
1142
1143   FGInterface::set_Velocities_Body(u, v, w);
1144 }
1145
1146 //Euler angles
1147 void FGJSBsim::set_Euler_Angles( double phi, double theta, double psi )
1148 {
1149   SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Euler_Angles: "
1150      << phi << ", " << theta << ", " << psi );
1151
1152   if (needTrim) {
1153     fgic->SetThetaRadIC(theta);
1154     fgic->SetPhiRadIC(phi);
1155     fgic->SetPsiRadIC(psi);
1156   }
1157   else {
1158     FGQuaternion quat(phi, theta, psi);
1159     FGMatrix33 Tl2b = quat.GetT();
1160     FGMatrix33 Ti2b = Tl2b*Propagate->GetTi2l();
1161     FGQuaternion Qi = Ti2b.GetQuaternion();
1162     Propagate->SetInertialOrientation(Qi);
1163   }
1164
1165   FGInterface::set_Euler_Angles(phi, theta, psi);
1166 }
1167
1168 //Flight Path
1169 void FGJSBsim::set_Climb_Rate( double roc)
1170 {
1171   SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Climb_Rate: " << roc );
1172
1173   //since both climb rate and flight path angle are set in the FG
1174   //startup sequence, something is needed to keep one from cancelling
1175   //out the other.
1176   if( fabs(roc) > 1 && fabs(fgic->GetFlightPathAngleRadIC()) < 0.01 ) {
1177     if (needTrim)
1178       fgic->SetClimbRateFpsIC(roc);
1179     else {
1180       FGColumnVector3 vNED = Propagate->GetVel();
1181       vNED(FGJSBBase::eDown) = -roc;
1182       FGColumnVector3 vUVW = Propagate->GetTl2b() * vNED;
1183       Propagate->SetUVW(1, vUVW(1));
1184       Propagate->SetUVW(2, vUVW(2));
1185       Propagate->SetUVW(3, vUVW(3));
1186     }
1187
1188     FGInterface::set_Climb_Rate(roc);
1189   }
1190 }
1191
1192 void FGJSBsim::set_Gamma_vert_rad( double gamma)
1193 {
1194   SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Gamma_vert_rad: " << gamma );
1195
1196   if( !(fabs(gamma) < 0.01 && fabs(fgic->GetClimbRateFpsIC()) > 1) ) {
1197     if (needTrim)
1198       fgic->SetFlightPathAngleRadIC(gamma);
1199     else {
1200       FGColumnVector3 vNED = Propagate->GetVel();
1201       double vt = vNED.Magnitude();
1202       vNED(FGJSBBase::eDown) = -vt * sin(gamma);
1203       FGColumnVector3 vUVW = Propagate->GetTl2b() * vNED;
1204       Propagate->SetUVW(1, vUVW(1));
1205       Propagate->SetUVW(2, vUVW(2));
1206       Propagate->SetUVW(3, vUVW(3));
1207     }
1208
1209     FGInterface::set_Gamma_vert_rad(gamma);
1210   }
1211 }
1212
1213 void FGJSBsim::init_gear(void )
1214 {
1215     FGGroundReactions* gr=fdmex->GetGroundReactions();
1216     int Ngear=GroundReactions->GetNumGearUnits();
1217     for (int i=0;i<Ngear;i++) {
1218       FGLGear *gear = gr->GetGearUnit(i);
1219       SGPropertyNode * node = fgGetNode("gear/gear", i, true);
1220       node->setDoubleValue("xoffset-in", gear->GetBodyLocation()(1) * 12);
1221       node->setDoubleValue("yoffset-in", gear->GetBodyLocation()(2) * 12);
1222       node->setDoubleValue("zoffset-in", gear->GetBodyLocation()(3) * 12);
1223       node->setBoolValue("wow", gear->GetWOW());
1224       node->setDoubleValue("rollspeed-ms", gear->GetWheelRollVel()*0.3043);
1225       node->setBoolValue("has-brake", gear->GetBrakeGroup() > 0);
1226       node->setDoubleValue("position-norm", gear->GetGearUnitPos());
1227 //    node->setDoubleValue("tire-pressure-norm", gear->GetTirePressure());
1228       node->setDoubleValue("compression-norm", gear->GetCompLen());
1229       node->setDoubleValue("compression-ft", gear->GetCompLen());
1230       if ( gear->GetSteerable() )
1231         node->setDoubleValue("steering-norm", gear->GetSteerNorm());
1232     }
1233 }
1234
1235 void FGJSBsim::update_gear(void)
1236 {
1237     FGGroundReactions* gr=fdmex->GetGroundReactions();
1238     int Ngear=GroundReactions->GetNumGearUnits();
1239     for (int i=0;i<Ngear;i++) {
1240       FGLGear *gear = gr->GetGearUnit(i);
1241       SGPropertyNode * node = fgGetNode("gear/gear", i, true);
1242       node->getChild("wow", 0, true)->setBoolValue( gear->GetWOW());
1243       node->getChild("rollspeed-ms", 0, true)->setDoubleValue(gear->GetWheelRollVel()*0.3043);
1244       node->getChild("position-norm", 0, true)->setDoubleValue(gear->GetGearUnitPos());
1245 //    gear->SetTirePressure(node->getDoubleValue("tire-pressure-norm"));
1246       node->setDoubleValue("compression-norm", gear->GetCompLen());
1247       node->setDoubleValue("compression-ft", gear->GetCompLen());
1248       if ( gear->GetSteerable() )
1249         node->setDoubleValue("steering-norm", gear->GetSteerNorm());
1250     }
1251 }
1252
1253 void FGJSBsim::do_trim(void)
1254 {
1255   FGTrim *fgtrim;
1256
1257   if ( fgGetBool("/sim/presets/onground") )
1258   {
1259     fgtrim = new FGTrim(fdmex,tGround);
1260   } else {
1261     fgtrim = new FGTrim(fdmex,tFull);
1262   }
1263
1264   if ( !fgtrim->DoTrim() ) {
1265     fgtrim->Report();
1266     fgtrim->TrimStats();
1267   } else {
1268     trimmed->setBoolValue(true);
1269   }
1270   delete fgtrim;
1271
1272   pitch_trim->setDoubleValue( FCS->GetPitchTrimCmd() );
1273   throttle_trim->setDoubleValue( FCS->GetThrottleCmd(0) );
1274   aileron_trim->setDoubleValue( FCS->GetDaCmd() );
1275   rudder_trim->setDoubleValue( -FCS->GetDrCmd() );
1276
1277   globals->get_controls()->set_elevator_trim(FCS->GetPitchTrimCmd());
1278   globals->get_controls()->set_elevator(FCS->GetDeCmd());
1279   for( unsigned i = 0; i < Propulsion->GetNumEngines(); i++ )
1280     globals->get_controls()->set_throttle(i, FCS->GetThrottleCmd(i));
1281
1282   globals->get_controls()->set_aileron(FCS->GetDaCmd());
1283   globals->get_controls()->set_rudder( -FCS->GetDrCmd());
1284
1285   SG_LOG( SG_FLIGHT, SG_INFO, "  Trim complete" );
1286 }
1287
1288 bool FGJSBsim::update_ground_cache(FGLocation cart, double* cart_pos, double dt)
1289 {
1290   // Compute the radius of the aircraft. That is the radius of a ball
1291   // where all gear units are in. At the moment it is at least 10ft ...
1292   double acrad = 10.0;
1293   int n_gears = GroundReactions->GetNumGearUnits();
1294   for (int i=0; i<n_gears; ++i) {
1295     FGColumnVector3 bl = GroundReactions->GetGearUnit(i)->GetBodyLocation();
1296     double r = bl.Magnitude();
1297     if (acrad < r)
1298       acrad = r;
1299   }
1300
1301   // Compute the potential movement of this aircraft and query for the
1302   // ground in this area.
1303   double groundCacheRadius = acrad + 2*dt*Propagate->GetUVW().Magnitude();
1304   cart_pos[0] = cart(1);
1305   cart_pos[1] = cart(2);
1306   cart_pos[2] = cart(3);
1307   double t0 = fdmex->GetSimTime();
1308   bool cache_ok = prepare_ground_cache_ft( t0, t0 + dt, cart_pos,
1309                                            groundCacheRadius );
1310   if (!cache_ok) {
1311     SG_LOG(SG_FLIGHT, SG_WARN,
1312            "FGInterface is being called without scenery below the aircraft!");
1313
1314     SG_LOG(SG_FLIGHT, SG_WARN, "altitude         = "
1315                       << fgic->GetAltitudeASLFtIC());
1316
1317     SG_LOG(SG_FLIGHT, SG_WARN, "sea level radius = "
1318                       << get_Sea_level_radius());
1319
1320     SG_LOG(SG_FLIGHT, SG_WARN, "latitude         = "
1321                       << fgic->GetLatitudeRadIC());
1322
1323     SG_LOG(SG_FLIGHT, SG_WARN, "longitude        = "
1324                       << fgic->GetLongitudeRadIC());
1325   }
1326
1327   return cache_ok;
1328 }
1329
1330 bool
1331 FGJSBsim::get_agl_ft(double t, const double pt[3], double alt_off,
1332                      double contact[3], double normal[3], double vel[3],
1333                      double angularVel[3], double *agl)
1334 {
1335    const simgear::BVHMaterial* material;
1336    simgear::BVHNode::Id id;
1337    if (!FGInterface::get_agl_ft(t, pt, alt_off, contact, normal, vel,
1338                                 angularVel, material, id))
1339        return false;
1340    SGGeod geodPt = SGGeod::fromCart(SG_FEET_TO_METER*SGVec3d(pt));
1341    SGQuatd hlToEc = SGQuatd::fromLonLat(geodPt);
1342    *agl = dot(hlToEc.rotate(SGVec3d(0, 0, 1)), SGVec3d(contact) - SGVec3d(pt));
1343    return true;
1344 }
1345
1346 inline static double sqr(double x)
1347 {
1348     return x * x;
1349 }
1350
1351 static double angle_diff(double a, double b)
1352 {
1353     double diff = fabs(a - b);
1354     if (diff > 180) diff = 360 - diff;
1355
1356     return diff;
1357 }
1358
1359 static void check_hook_solution(const FGColumnVector3& ground_normal_body, double E, double hook_length, double sin_fi_guess, double cos_fi_guess, double* sin_fis, double* cos_fis, double* fis, int* points)
1360 {
1361     FGColumnVector3 tip(-hook_length * cos_fi_guess, 0, hook_length * sin_fi_guess);
1362     double dist = DotProduct(tip, ground_normal_body);
1363     if (fabs(dist + E) < 0.0001) {
1364         sin_fis[*points] = sin_fi_guess;
1365         cos_fis[*points] = cos_fi_guess;
1366         fis[*points] = atan2(sin_fi_guess, cos_fi_guess) * SG_RADIANS_TO_DEGREES;
1367         (*points)++;
1368     }
1369 }
1370
1371
1372 static void check_hook_solution(const FGColumnVector3& ground_normal_body, double E, double hook_length, double sin_fi_guess, double* sin_fis, double* cos_fis, double* fis, int* points)
1373 {
1374     if (sin_fi_guess >= -1 && sin_fi_guess <= 1) {
1375         double cos_fi_guess = sqrt(1 - sqr(sin_fi_guess));
1376         check_hook_solution(ground_normal_body, E, hook_length, sin_fi_guess, cos_fi_guess, sin_fis, cos_fis, fis, points);
1377         if (fabs(cos_fi_guess) > SG_EPSILON) {
1378             check_hook_solution(ground_normal_body, E, hook_length, sin_fi_guess, -cos_fi_guess, sin_fis, cos_fis, fis, points);
1379         }
1380     }
1381 }
1382
1383 void FGJSBsim::update_external_forces(double t_off)
1384 {
1385     const FGMatrix33& Tb2l = Propagate->GetTb2l();
1386     const FGMatrix33& Tl2b = Propagate->GetTl2b();
1387     const FGLocation& Location = Propagate->GetLocation();
1388     const FGMatrix33& Tec2l = Location.GetTec2l();
1389
1390     double hook_area[4][3];
1391
1392     FGColumnVector3 hook_root_body = MassBalance->StructuralToBody(hook_root_struct);
1393     FGColumnVector3 hook_root = Location.LocalToLocation(Tb2l *   hook_root_body);
1394     hook_area[1][0] = hook_root(1);
1395     hook_area[1][1] = hook_root(2);
1396     hook_area[1][2] = hook_root(3);
1397
1398     hook_length = fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-length-ft", 6.75);
1399     double fi_min = fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-min-deg", -18);
1400     double fi_max = fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-max-deg", 30);
1401     double fi = fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-norm") * (fi_max - fi_min) + fi_min;
1402     double cos_fi = cos(fi * SG_DEGREES_TO_RADIANS);
1403     double sin_fi = sin(fi * SG_DEGREES_TO_RADIANS);
1404
1405     FGColumnVector3 hook_tip_body = hook_root_body;
1406     hook_tip_body(1) -= hook_length * cos_fi;
1407     hook_tip_body(3) += hook_length * sin_fi;
1408
1409     double contact[3];
1410     double ground_normal[3];
1411     double ground_vel[3];
1412     double ground_angular_vel[3];
1413     double root_agl_ft;
1414
1415     if (!got_wire) {
1416         bool got = get_agl_ft(t_off, hook_area[1], 0, contact, ground_normal,
1417                               ground_vel, ground_angular_vel, &root_agl_ft);
1418         if (got && root_agl_ft > 0 && root_agl_ft < hook_length) {
1419             FGColumnVector3 ground_normal_body = Tl2b * (Tec2l * FGColumnVector3(ground_normal[0], ground_normal[1], ground_normal[2]));
1420             FGColumnVector3 contact_body = Tl2b * Location.LocationToLocal(FGColumnVector3(contact[0], contact[1], contact[2]));
1421             double D = -DotProduct(contact_body, ground_normal_body);
1422
1423             // check hook tip agl against same ground plane
1424             double hook_tip_agl_ft = DotProduct(hook_tip_body, ground_normal_body) + D;
1425             if (hook_tip_agl_ft < 0) {
1426
1427                 // hook tip: hx - l cos, hy, hz + l sin
1428                 // on ground:  - n0 l cos + n2 l sin + E = 0
1429
1430                 double E = D + DotProduct(hook_root_body, ground_normal_body);
1431
1432                 // substitue x = sin fi, cos fi = sqrt(1 - x * x)
1433                 // and rearrange to get a quadratic with coeffs:
1434                 double a = sqr(hook_length) * (sqr(ground_normal_body(1)) + sqr(ground_normal_body(3)));
1435                 double b = 2 * E * ground_normal_body(3) * hook_length;
1436                 double c = sqr(E) - sqr(ground_normal_body(1) * hook_length);
1437
1438                 double disc = sqr(b) - 4 * a * c;
1439                 if (disc >= 0) {
1440                     double delta = sqrt(disc) / (2 * a);
1441
1442                     // allow 4 solutions for safety, should never happen
1443                     double sin_fis[4];
1444                     double cos_fis[4];
1445                     double fis[4];
1446                     int points = 0;
1447
1448                     double sin_fi_guess = -b / (2 * a) - delta;
1449                     check_hook_solution(ground_normal_body, E, hook_length, sin_fi_guess, sin_fis, cos_fis, fis, &points);
1450                     check_hook_solution(ground_normal_body, E, hook_length, sin_fi_guess + 2 * delta, sin_fis, cos_fis, fis, &points);
1451
1452                     if (points == 2) {
1453                         double diff1 = angle_diff(fi, fis[0]);
1454                         double diff2 = angle_diff(fi, fis[1]);
1455                         int point = diff1 < diff2 ? 0 : 1;
1456                         fi = fis[point];
1457                         sin_fi = sin_fis[point];
1458                         cos_fi = cos_fis[point];
1459                         hook_tip_body(1) = hook_root_body(1) - hook_length * cos_fi;
1460                         hook_tip_body(3) = hook_root_body(3) + hook_length * sin_fi;
1461                     }
1462                 }
1463             }
1464         }
1465     } else {
1466         FGColumnVector3 hook_root_vel = Propagate->GetVel() + (Tb2l * (Propagate->GetPQR() *  hook_root_body));
1467         double wire_ends_ec[2][3];
1468         double wire_vel_ec[2][3];
1469         get_wire_ends_ft(t_off, wire_ends_ec, wire_vel_ec);
1470         FGColumnVector3 wire_vel_1 = Tec2l * FGColumnVector3(wire_vel_ec[0][0], wire_vel_ec[0][1], wire_vel_ec[0][2]);
1471         FGColumnVector3 wire_vel_2 = Tec2l * FGColumnVector3(wire_vel_ec[1][0], wire_vel_ec[1][1], wire_vel_ec[1][2]);
1472         FGColumnVector3 rel_vel = hook_root_vel - (wire_vel_1 + wire_vel_2) / 2;
1473         if (rel_vel.Magnitude() < 3) {
1474             got_wire = false;
1475             release_wire();
1476             fgSetDouble("/fdm/jsbsim/external_reactions/hook/magnitude", 0.0);
1477         } else {
1478             FGColumnVector3 wire_end1_body = Tl2b * Location.LocationToLocal(FGColumnVector3(wire_ends_ec[0][0], wire_ends_ec[0][1], wire_ends_ec[0][2])) - hook_root_body;
1479             FGColumnVector3 wire_end2_body = Tl2b * Location.LocationToLocal(FGColumnVector3(wire_ends_ec[1][0], wire_ends_ec[1][1], wire_ends_ec[1][2])) - hook_root_body;
1480             FGColumnVector3 force_plane_normal = wire_end1_body * wire_end2_body;
1481             force_plane_normal.Normalize();
1482             cos_fi = DotProduct(force_plane_normal, FGColumnVector3(0, 0, 1));
1483             if (cos_fi < 0) cos_fi = -cos_fi;
1484             sin_fi = sqrt(1 - sqr(cos_fi));
1485             fi = atan2(sin_fi, cos_fi) * SG_RADIANS_TO_DEGREES;
1486
1487             fgSetDouble("/fdm/jsbsim/external_reactions/hook/x", -cos_fi);
1488             fgSetDouble("/fdm/jsbsim/external_reactions/hook/y", 0);
1489             fgSetDouble("/fdm/jsbsim/external_reactions/hook/z", sin_fi);
1490             fgSetDouble("/fdm/jsbsim/external_reactions/hook/magnitude", fgGetDouble("/fdm/jsbsim/systems/hook/force"));
1491         }
1492     }
1493
1494     FGColumnVector3 hook_tip = Location.LocalToLocation(Tb2l * hook_tip_body);
1495
1496     hook_area[0][0] = hook_tip(1);
1497     hook_area[0][1] = hook_tip(2);
1498     hook_area[0][2] = hook_tip(3);
1499
1500     if (!got_wire) {
1501         // The previous positions.
1502         hook_area[2][0] = last_hook_root[0];
1503         hook_area[2][1] = last_hook_root[1];
1504         hook_area[2][2] = last_hook_root[2];
1505         hook_area[3][0] = last_hook_tip[0];
1506         hook_area[3][1] = last_hook_tip[1];
1507         hook_area[3][2] = last_hook_tip[2];
1508
1509         // Check if we caught a wire.
1510         // Returns true if we caught one.
1511         if (caught_wire_ft(t_off, hook_area)) {
1512                 got_wire = true;
1513         }
1514     }
1515
1516     // save actual position as old position ...
1517     last_hook_tip[0] = hook_area[0][0];
1518     last_hook_tip[1] = hook_area[0][1];
1519     last_hook_tip[2] = hook_area[0][2];
1520     last_hook_root[0] = hook_area[1][0];
1521     last_hook_root[1] = hook_area[1][1];
1522     last_hook_root[2] = hook_area[1][2];
1523
1524     fgSetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-deg", fi);
1525 }
1526