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., 675 Mass Ave, Cambridge, MA 02139, 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
  30 #include <stdio.h>    //    size_t
  31 #include <string>
  32
  33 #include <simgear/constants.h>
  34 #include <simgear/debug/logstream.hxx>
  35 #include <simgear/math/sg_geodesy.hxx>
  36 #include <simgear/misc/sg_path.hxx>
  37 #include <simgear/structure/commands.hxx>
  38
  39 #include <FDM/flight.hxx>
  40
  41 #include <Aircraft/controls.hxx>
  42 #include <Main/globals.hxx>
  43 #include <Main/fg_props.hxx>
  44
  45 #include "JSBSim.hxx"
  46 #include <FDM/JSBSim/FGFDMExec.h>
  47 #include <FDM/JSBSim/FGJSBBase.h>
  48 #include <FDM/JSBSim/initialization/FGInitialCondition.h>
  49 #include <FDM/JSBSim/initialization/FGTrim.h>
  50 #include <FDM/JSBSim/models/FGModel.h>
  51 #include <FDM/JSBSim/models/FGAircraft.h>
  52 #include <FDM/JSBSim/models/FGFCS.h>
  53 #include <FDM/JSBSim/models/FGPropagate.h>
  54 #include <FDM/JSBSim/models/FGAuxiliary.h>
  55 #include <FDM/JSBSim/models/FGInertial.h>
  56 #include <FDM/JSBSim/models/FGAtmosphere.h>
  57 #include <FDM/JSBSim/models/FGMassBalance.h>
  58 #include <FDM/JSBSim/models/FGAerodynamics.h>
  59 #include <FDM/JSBSim/models/FGLGear.h>
  60 #include <FDM/JSBSim/models/FGGroundReactions.h>
  61 #include <FDM/JSBSim/models/FGPropulsion.h>
  62 #include <FDM/JSBSim/models/propulsion/FGEngine.h>
  63 #include <FDM/JSBSim/models/propulsion/FGPiston.h>
  64 #include <FDM/JSBSim/models/propulsion/FGTurbine.h>
  65 #include <FDM/JSBSim/models/propulsion/FGTurboProp.h>
  66 #include <FDM/JSBSim/models/propulsion/FGRocket.h>
  67 #include <FDM/JSBSim/models/propulsion/FGElectric.h>
  68 #include <FDM/JSBSim/models/propulsion/FGNozzle.h>
  69 #include <FDM/JSBSim/models/propulsion/FGPropeller.h>
  70 #include <FDM/JSBSim/models/propulsion/FGRotor.h>
  71 #include <FDM/JSBSim/models/propulsion/FGTank.h>
  72 #include <FDM/JSBSim/input_output/FGPropertyManager.h>
  73 #include <FDM/JSBSim/input_output/FGGroundCallback.h>
  74
  75 using namespace JSBSim;
  76
  77 static inline double
  78 FMAX (double a, double b)
  79 {
  80   return a > b ? a : b;
  81 }
  82
  83 class FGFSGroundCallback : public FGGroundCallback {
  84 public:
  85   FGFSGroundCallback(FGJSBsim* ifc) : mInterface(ifc) {}
  86   virtual ~FGFSGroundCallback() {}
  87
  88   /** Get the altitude above sea level dependent on the location. */
  89   virtual double GetAltitude(const FGLocation& l) const {
  90     double pt[3] = { SG_FEET_TO_METER*l(eX),
  91                      SG_FEET_TO_METER*l(eY),
  92                      SG_FEET_TO_METER*l(eZ) };
  93     double lat, lon, alt;
  94     sgCartToGeod( pt, &lat, &lon, &alt);
  95     return alt * SG_METER_TO_FEET;
  96   }
  97
  98   /** Compute the altitude above ground. */
  99   virtual double GetAGLevel(double t, const FGLocation& l,
 100                             FGLocation& cont, FGColumnVector3& n,
 101                             FGColumnVector3& v, FGColumnVector3& w) const {
 102     double loc_cart[3] = { l(eX), l(eY), l(eZ) };
 103     double contact[3], normal[3], vel[3], angularVel[3], agl = 0;
 104     mInterface->get_agl_ft(t, loc_cart, SG_METER_TO_FEET*2, contact, normal,
 105                            vel, angularVel, &agl);
 106     n = FGColumnVector3( normal[0], normal[1], normal[2] );
 107     v = FGColumnVector3( vel[0], vel[1], vel[2] );
 108     w = FGColumnVector3( angularVel[0], angularVel[1], angularVel[2] );
 109     cont = FGColumnVector3( contact[0], contact[1], contact[2] );
 110     return agl;
 111   }
 112 private:
 113   FGJSBsim* mInterface;
 114 };
 115
 116 /******************************************************************************/
 117
 118 FGJSBsim::FGJSBsim( double dt )
 119   : FGInterface(dt), got_wire(false)
 120 {
 121     bool result;
 122                                 // Set up the debugging level
 123                                 // FIXME: this will not respond to
 124                                 // runtime changes
 125
 126                                 // if flight is excluded, don't bother
 127     if ((logbuf::get_log_classes() & SG_FLIGHT) != 0) {
 128
 129                                 // do a rough-and-ready mapping to
 130                                 // the levels documented in FGFDMExec.h
 131         switch (logbuf::get_log_priority()) {
 132         case SG_BULK:
 133             FGJSBBase::debug_lvl = 0x1f;
 134             break;
 135         case SG_DEBUG:
 136             FGJSBBase::debug_lvl = 0x0f;
 137         case SG_INFO:
 138             FGJSBBase::debug_lvl = 0x01;
 139             break;
 140         case SG_WARN:
 141         case SG_ALERT:
 142             FGJSBBase::debug_lvl = 0x00;
 143             break;
 144         }
 145     }
 146
 147     resetPropertyState();
 148
 149     fdmex = new FGFDMExec( (FGPropertyManager*)globals->get_props() );
 150
 151     // Register ground callback.
 152     fdmex->SetGroundCallback( new FGFSGroundCallback(this) );
 153
 154     Atmosphere      = fdmex->GetAtmosphere();
 155     FCS             = fdmex->GetFCS();
 156     MassBalance     = fdmex->GetMassBalance();
 157     Propulsion      = fdmex->GetPropulsion();
 158     Aircraft        = fdmex->GetAircraft();
 159     Propagate        = fdmex->GetPropagate();
 160     Auxiliary       = fdmex->GetAuxiliary();
 161     Inertial        = fdmex->GetInertial();
 162     Aerodynamics    = fdmex->GetAerodynamics();
 163     GroundReactions = fdmex->GetGroundReactions();
 164
 165     fgic=fdmex->GetIC();
 166     needTrim=true;
 167
 168     SGPath aircraft_path( fgGetString("/sim/aircraft-dir") );
 169
 170     SGPath engine_path( fgGetString("/sim/aircraft-dir") );
 171     engine_path.append( "Engine" );
 172
 173     SGPath systems_path( fgGetString("/sim/aircraft-dir") );
 174     systems_path.append( "Systems" );
 175
 176 // deprecate sim-time-sec for simulation/sim-time-sec
 177 // remove alias with increased configuration file version number (2.1 or later)
 178     SGPropertyNode * node = fgGetNode("/fdm/jsbsim/simulation/sim-time-sec");
 179     fgGetNode("/fdm/jsbsim/sim-time-sec", true)->alias( node );
 180 // end of sim-time-sec deprecation patch
 181
 182     fdmex->Setdt( dt );
 183
 184     result = fdmex->LoadModel( aircraft_path.str(),
 185                                engine_path.str(),
 186                                systems_path.str(),
 187                                fgGetString("/sim/aero"), false );
 188
 189     if (result) {
 190       SG_LOG( SG_FLIGHT, SG_INFO, "  loaded aero.");
 191     } else {
 192       SG_LOG( SG_FLIGHT, SG_INFO,
 193               "  aero does not exist (you may have mis-typed the name).");
 194       throw(-1);
 195     }
 196
 197     SG_LOG( SG_FLIGHT, SG_INFO, "" );
 198     SG_LOG( SG_FLIGHT, SG_INFO, "" );
 199     SG_LOG( SG_FLIGHT, SG_INFO, "After loading aero definition file ..." );
 200
 201     int Neng = Propulsion->GetNumEngines();
 202     SG_LOG( SG_FLIGHT, SG_INFO, "num engines = " << Neng );
 203
 204     if ( GroundReactions->GetNumGearUnits() <= 0 ) {
 205         SG_LOG( SG_FLIGHT, SG_ALERT, "num gear units = "
 206                 << GroundReactions->GetNumGearUnits() );
 207         SG_LOG( SG_FLIGHT, SG_ALERT, "This is a very bad thing because with 0 gear units, the ground trimming");
 208         SG_LOG( SG_FLIGHT, SG_ALERT, "routine (coming up later in the code) will core dump.");
 209         SG_LOG( SG_FLIGHT, SG_ALERT, "Halting the sim now, and hoping a solution will present itself soon!");
 210         exit(-1);
 211     }
 212
 213     init_gear();
 214
 215     // Set initial fuel levels if provided.
 216     for (unsigned int i = 0; i < Propulsion->GetNumTanks(); i++) {
 217       SGPropertyNode * node = fgGetNode("/consumables/fuel/tank", i, true);
 218       if (node->getChild("level-gal_us", 0, false) != 0) {
 219         Propulsion->GetTank(i)->SetContents(node->getDoubleValue("level-gal_us") * 6.6);
 220       } else {
 221         node->setDoubleValue("level-lbs", Propulsion->GetTank(i)->GetContents());
 222         node->setDoubleValue("level-gal_us", Propulsion->GetTank(i)->GetContents() / 6.6);
 223       }
 224       node->setDoubleValue("capacity-gal_us",
 225                            Propulsion->GetTank(i)->GetCapacity() / 6.6);
 226     }
 227     Propulsion->SetFuelFreeze((fgGetNode("/sim/freeze/fuel",true))->getBoolValue());
 228
 229     fgSetDouble("/fdm/trim/pitch-trim", FCS->GetPitchTrimCmd());
 230     fgSetDouble("/fdm/trim/throttle",   FCS->GetThrottleCmd(0));
 231     fgSetDouble("/fdm/trim/aileron",    FCS->GetDaCmd());
 232     fgSetDouble("/fdm/trim/rudder",     FCS->GetDrCmd());
 233
 234     startup_trim = fgGetNode("/sim/presets/trim", true);
 235
 236     trimmed = fgGetNode("/fdm/trim/trimmed", true);
 237     trimmed->setBoolValue(false);
 238
 239     pitch_trim = fgGetNode("/fdm/trim/pitch-trim", true );
 240     throttle_trim = fgGetNode("/fdm/trim/throttle", true );
 241     aileron_trim = fgGetNode("/fdm/trim/aileron", true );
 242     rudder_trim = fgGetNode("/fdm/trim/rudder", true );
 243
 244     stall_warning = fgGetNode("/sim/alarms/stall-warning",true);
 245     stall_warning->setDoubleValue(0);
 246
 247
 248     flap_pos_pct=fgGetNode("/surface-positions/flap-pos-norm",true);
 249     elevator_pos_pct=fgGetNode("/surface-positions/elevator-pos-norm",true);
 250     left_aileron_pos_pct
 251         =fgGetNode("/surface-positions/left-aileron-pos-norm",true);
 252     right_aileron_pos_pct
 253         =fgGetNode("/surface-positions/right-aileron-pos-norm",true);
 254     rudder_pos_pct=fgGetNode("/surface-positions/rudder-pos-norm",true);
 255     speedbrake_pos_pct
 256         =fgGetNode("/surface-positions/speedbrake-pos-norm",true);
 257     spoilers_pos_pct=fgGetNode("/surface-positions/spoilers-pos-norm",true);
 258     tailhook_pos_pct=fgGetNode("/gear/tailhook/position-norm",true);
 259     wing_fold_pos_pct=fgGetNode("surface-positions/wing-fold-pos-norm",true);
 260
 261     elevator_pos_pct->setDoubleValue(0);
 262     left_aileron_pos_pct->setDoubleValue(0);
 263     right_aileron_pos_pct->setDoubleValue(0);
 264     rudder_pos_pct->setDoubleValue(0);
 265     flap_pos_pct->setDoubleValue(0);
 266     speedbrake_pos_pct->setDoubleValue(0);
 267     spoilers_pos_pct->setDoubleValue(0);
 268
 269     ab_brake_engaged = fgGetNode("/autopilot/autobrake/engaged", true);
 270     ab_brake_left_pct = fgGetNode("/autopilot/autobrake/brake-left-output", true);
 271     ab_brake_right_pct = fgGetNode("/autopilot/autobrake/brake-right-output", true);
 272
 273     temperature = fgGetNode("/environment/temperature-degc",true);
 274     pressure = fgGetNode("/environment/pressure-inhg",true);
 275     density = fgGetNode("/environment/density-slugft3",true);
 276     turbulence_gain = fgGetNode("/environment/turbulence/magnitude-norm",true);
 277     turbulence_rate = fgGetNode("/environment/turbulence/rate-hz",true);
 278
 279     wind_from_north= fgGetNode("/environment/wind-from-north-fps",true);
 280     wind_from_east = fgGetNode("/environment/wind-from-east-fps" ,true);
 281     wind_from_down = fgGetNode("/environment/wind-from-down-fps" ,true);
 282
 283     slaved = fgGetNode("/sim/slaved/enabled", true);
 284
 285     for (unsigned int i = 0; i < Propulsion->GetNumEngines(); i++) {
 286       SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 287       Propulsion->GetEngine(i)->GetThruster()->SetRPM(node->getDoubleValue("rpm") /
 288                      Propulsion->GetEngine(i)->GetThruster()->GetGearRatio());
 289     }
 290
 291     hook_root_struct = FGColumnVector3(
 292         fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-offset-x-in", 196),
 293         fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-offset-y-in", 0),
 294         fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-offset-z-in", -16));
 295
 296     crashed = false;
 297 }
 298
 299 /******************************************************************************/
 300 FGJSBsim::~FGJSBsim(void)
 301 {
 302   delete fdmex;
 303 }
 304
 305 /******************************************************************************/
 306
 307 // Initialize the JSBsim flight model, dt is the time increment for
 308 // each subsequent iteration through the EOM
 309
 310 void FGJSBsim::init()
 311 {
 312     SG_LOG( SG_FLIGHT, SG_INFO, "Starting and initializing JSBsim" );
 313
 314     // Explicitly call the superclass's
 315     // init method first.
 316
 317     if (fgGetBool("/environment/params/control-fdm-atmosphere")) {
 318       Atmosphere->UseExternal();
 319       Atmosphere->SetExTemperature(
 320                   9.0/5.0*(temperature->getDoubleValue()+273.15) );
 321       Atmosphere->SetExPressure(pressure->getDoubleValue()*70.726566);
 322       Atmosphere->SetExDensity(density->getDoubleValue());
 323       Atmosphere->SetTurbType(FGAtmosphere::ttCulp);
 324       Atmosphere->SetTurbGain(turbulence_gain->getDoubleValue());
 325       Atmosphere->SetTurbRate(turbulence_rate->getDoubleValue());
 326
 327     } else {
 328       Atmosphere->UseInternal();
 329     }
 330
 331     fgic->SetVNorthFpsIC( -wind_from_north->getDoubleValue() );
 332     fgic->SetVEastFpsIC( -wind_from_east->getDoubleValue() );
 333     fgic->SetVDownFpsIC( -wind_from_down->getDoubleValue() );
 334
 335     //Atmosphere->SetExTemperature(get_Static_temperature());
 336     //Atmosphere->SetExPressure(get_Static_pressure());
 337     //Atmosphere->SetExDensity(get_Density());
 338     SG_LOG(SG_FLIGHT,SG_INFO,"T,p,rho: " << fdmex->GetAtmosphere()->GetTemperature()
 339      << ", " << fdmex->GetAtmosphere()->GetPressure()
 340      << ", " << fdmex->GetAtmosphere()->GetDensity() );
 341
 342 // deprecate egt_degf for egt-degf to have consistent naming
 343 // TODO: raise log-level to ALERT in summer 2010,
 344 // remove alias in fall 2010,
 345 // remove this code in winter 2010
 346     for (unsigned int i=0; i < Propulsion->GetNumEngines(); i++) {
 347       SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 348       SGPropertyNode * egtn = node->getNode( "egt_degf" );
 349       if( egtn != NULL ) {
 350         SG_LOG(SG_FLIGHT,SG_WARN,
 351                "Aircraft uses deprecated node egt_degf. Please upgrade to egt-degf");
 352         node->getNode("egt-degf", true)->alias( egtn );
 353       }
 354     }
 355 // end of egt_degf deprecation patch
 356
 357     if (fgGetBool("/sim/presets/running")) {
 358           for (unsigned int i=0; i < Propulsion->GetNumEngines(); i++) {
 359             SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 360             node->setBoolValue("running", true);
 361             Propulsion->GetEngine(i)->SetRunning(true);
 362           }
 363     }
 364
 365     FCS->SetDfPos( ofNorm, globals->get_controls()->get_flaps() );
 366
 367     common_init();
 368
 369     copy_to_JSBsim();
 370     fdmex->RunIC();     //loop JSBSim once w/o integrating
 371     copy_from_JSBsim(); //update the bus
 372
 373     SG_LOG( SG_FLIGHT, SG_INFO, "  Initialized JSBSim with:" );
 374
 375     switch(fgic->GetSpeedSet()) {
 376     case setned:
 377         SG_LOG(SG_FLIGHT,SG_INFO, "  Vn,Ve,Vd= "
 378                << Propagate->GetVel(FGJSBBase::eNorth) << ", "
 379                << Propagate->GetVel(FGJSBBase::eEast) << ", "
 380                << Propagate->GetVel(FGJSBBase::eDown) << " ft/s");
 381     break;
 382     case setuvw:
 383         SG_LOG(SG_FLIGHT,SG_INFO, "  U,V,W= "
 384                << Propagate->GetUVW(1) << ", "
 385                << Propagate->GetUVW(2) << ", "
 386                << Propagate->GetUVW(3) << " ft/s");
 387     break;
 388     case setmach:
 389         SG_LOG(SG_FLIGHT,SG_INFO, "  Mach: "
 390                << Auxiliary->GetMach() );
 391     break;
 392     case setvc:
 393     default:
 394         SG_LOG(SG_FLIGHT,SG_INFO, "  Indicated Airspeed: "
 395                << Auxiliary->GetVcalibratedKTS() << " knots" );
 396     break;
 397     }
 398
 399     stall_warning->setDoubleValue(0);
 400
 401     SG_LOG( SG_FLIGHT, SG_INFO, "  Bank Angle: "
 402             << Propagate->GetEuler(FGJSBBase::ePhi)*RADTODEG << " deg" );
 403     SG_LOG( SG_FLIGHT, SG_INFO, "  Pitch Angle: "
 404             << Propagate->GetEuler(FGJSBBase::eTht)*RADTODEG << " deg" );
 405     SG_LOG( SG_FLIGHT, SG_INFO, "  True Heading: "
 406             << Propagate->GetEuler(FGJSBBase::ePsi)*RADTODEG << " deg" );
 407     SG_LOG( SG_FLIGHT, SG_INFO, "  Latitude: "
 408             << Propagate->GetLocation().GetLatitudeDeg() << " deg" );
 409     SG_LOG( SG_FLIGHT, SG_INFO, "  Longitude: "
 410             << Propagate->GetLocation().GetLongitudeDeg() << " deg" );
 411     SG_LOG( SG_FLIGHT, SG_INFO, "  Altitude: "
 412             << Propagate->GetAltitudeASL() << " feet" );
 413     SG_LOG( SG_FLIGHT, SG_INFO, "  loaded initial conditions" );
 414
 415     SG_LOG( SG_FLIGHT, SG_INFO, "  set dt" );
 416
 417     SG_LOG( SG_FLIGHT, SG_INFO, "Finished initializing JSBSim" );
 418
 419     SG_LOG( SG_FLIGHT, SG_INFO, "FGControls::get_gear_down()= " <<
 420                                   globals->get_controls()->get_gear_down() );
 421 }
 422
 423 /******************************************************************************/
 424
 425 // Run an iteration of the EOM (equations of motion)
 426
 427 void FGJSBsim::update( double dt )
 428 {
 429     if(crashed) {
 430       if(!fgGetBool("/sim/crashed"))
 431         fgSetBool("/sim/crashed", true);
 432       return;
 433     }
 434
 435     if (is_suspended())
 436       return;
 437
 438     int multiloop = _calc_multiloop(dt);
 439
 440     int i;
 441
 442     // Compute the radius of the aircraft. That is the radius of a ball
 443     // where all gear units are in. At the moment it is at least 10ft ...
 444     double acrad = 10.0;
 445     int n_gears = GroundReactions->GetNumGearUnits();
 446     for (i=0; i<n_gears; ++i) {
 447       FGColumnVector3 bl = GroundReactions->GetGearUnit(i)->GetBodyLocation();
 448       double r = bl.Magnitude();
 449       if (acrad < r)
 450         acrad = r;
 451     }
 452
 453     // Compute the potential movement of this aircraft and query for the
 454     // ground in this area.
 455     double groundCacheRadius = acrad + 2*dt*Propagate->GetUVW().Magnitude();
 456     double alt, slr, lat, lon;
 457     FGLocation cart = Auxiliary->GetLocationVRP();
 458     if ( needTrim && startup_trim->getBoolValue() ) {
 459       alt = fgic->GetAltitudeASLFtIC();
 460       slr = fgic->GetSeaLevelRadiusFtIC();
 461       lat = fgic->GetLatitudeDegIC() * SGD_DEGREES_TO_RADIANS;
 462       lon = fgic->GetLongitudeDegIC() * SGD_DEGREES_TO_RADIANS;
 463       cart = FGLocation(lon, lat, alt+slr);
 464     }
 465     double cart_pos[3] = { cart(1), cart(2), cart(3) };
 466     double t0 = fdmex->GetSimTime();
 467     bool cache_ok = prepare_ground_cache_ft( t0, t0 + dt, cart_pos,
 468                                              groundCacheRadius );
 469     if (!cache_ok) {
 470       SG_LOG(SG_FLIGHT, SG_WARN,
 471              "FGInterface is being called without scenery below the aircraft!");
 472
 473       alt = fgic->GetAltitudeASLFtIC();
 474       SG_LOG(SG_FLIGHT, SG_WARN, "altitude         = " << alt);
 475
 476       slr = fgic->GetSeaLevelRadiusFtIC();
 477       SG_LOG(SG_FLIGHT, SG_WARN, "sea level radius = " << slr);
 478
 479       lat = fgic->GetLatitudeDegIC() * SGD_DEGREES_TO_RADIANS;
 480       SG_LOG(SG_FLIGHT, SG_WARN, "latitude         = " << lat);
 481
 482       lon = fgic->GetLongitudeDegIC() * SGD_DEGREES_TO_RADIANS;
 483       SG_LOG(SG_FLIGHT, SG_WARN, "longitude        = " << lon);
 484       //return;
 485     }
 486
 487     copy_to_JSBsim();
 488
 489     trimmed->setBoolValue(false);
 490
 491     if ( needTrim ) {
 492       if ( startup_trim->getBoolValue() ) {
 493         double contact[3], d[3], vel[3], agl;
 494         get_agl_ft(fdmex->GetSimTime(), cart_pos, SG_METER_TO_FEET*2, contact,
 495                    d, vel, d, &agl);
 496         double terrain_alt = sqrt(contact[0]*contact[0] + contact[1]*contact[1]
 497              + contact[2]*contact[2]) - fgic->GetSeaLevelRadiusFtIC();
 498
 499         SG_LOG(SG_FLIGHT, SG_INFO,
 500           "Ready to trim, terrain elevation is: "
 501             << terrain_alt * SG_METER_TO_FEET );
 502
 503         if (fgGetBool("/sim/presets/onground")) {
 504           FGColumnVector3 gndVelNED = cart.GetTec2l()
 505                                     * FGColumnVector3(vel[0], vel[1], vel[2]);
 506           fgic->SetVNorthFpsIC(gndVelNED(1));
 507           fgic->SetVEastFpsIC(gndVelNED(2));
 508           fgic->SetVDownFpsIC(gndVelNED(3));
 509         }
 510         fgic->SetTerrainElevationFtIC( terrain_alt );
 511         do_trim();
 512       } else {
 513         fdmex->RunIC();  //apply any changes made through the set_ functions
 514       }
 515       needTrim = false;
 516     }
 517
 518     for ( i=0; i < multiloop; i++ ) {
 519       fdmex->Run();
 520       update_external_forces(fdmex->GetSimTime() + i * fdmex->GetDeltaT());
 521     }
 522
 523     FGJSBBase::Message* msg;
 524     while (msg = fdmex->ProcessNextMessage()) {
 525 //      msg = fdmex->ProcessNextMessage();
 526       switch (msg->type) {
 527       case FGJSBBase::Message::eText:
 528         if (msg->text == "Crash Detected: Simulation FREEZE.")
 529           crashed = true;
 530         SG_LOG( SG_FLIGHT, SG_INFO, msg->messageId << ": " << msg->text );
 531         break;
 532       case FGJSBBase::Message::eBool:
 533         SG_LOG( SG_FLIGHT, SG_INFO, msg->messageId << ": " << msg->text << " " << msg->bVal );
 534         break;
 535       case FGJSBBase::Message::eInteger:
 536         SG_LOG( SG_FLIGHT, SG_INFO, msg->messageId << ": " << msg->text << " " << msg->iVal );
 537         break;
 538       case FGJSBBase::Message::eDouble:
 539         SG_LOG( SG_FLIGHT, SG_INFO, msg->messageId << ": " << msg->text << " " << msg->dVal );
 540         break;
 541       default:
 542         SG_LOG( SG_FLIGHT, SG_INFO, "Unrecognized message type." );
 543         break;
 544       }
 545     }
 546
 547     // translate JSBsim back to FG structure so that the
 548     // autopilot (and the rest of the sim can use the updated values
 549     copy_from_JSBsim();
 550 }
 551
 552 /******************************************************************************/
 553
 554 // Convert from the FGInterface struct to the JSBsim generic_ struct
 555
 556 bool FGJSBsim::copy_to_JSBsim()
 557 {
 558     double tmp;
 559     unsigned int i;
 560
 561     // copy control positions into the JSBsim structure
 562
 563     FCS->SetDaCmd( globals->get_controls()->get_aileron());
 564     FCS->SetRollTrimCmd( globals->get_controls()->get_aileron_trim() );
 565     FCS->SetDeCmd( globals->get_controls()->get_elevator());
 566     FCS->SetPitchTrimCmd( globals->get_controls()->get_elevator_trim() );
 567     FCS->SetDrCmd( -globals->get_controls()->get_rudder() );
 568     FCS->SetYawTrimCmd( -globals->get_controls()->get_rudder_trim() );
 569     FCS->SetDsCmd( globals->get_controls()->get_rudder() );
 570     FCS->SetDfCmd( globals->get_controls()->get_flaps() );
 571     FCS->SetDsbCmd( globals->get_controls()->get_speedbrake() );
 572     FCS->SetDspCmd( globals->get_controls()->get_spoilers() );
 573
 574         // Parking brake sets minimum braking
 575         // level for mains.
 576     double parking_brake = globals->get_controls()->get_brake_parking();
 577     double left_brake = globals->get_controls()->get_brake_left();
 578     double right_brake = globals->get_controls()->get_brake_right();
 579
 580     if (ab_brake_engaged->getBoolValue()) {
 581       left_brake = ab_brake_left_pct->getDoubleValue();
 582       right_brake = ab_brake_right_pct->getDoubleValue();
 583     }
 584
 585     FCS->SetLBrake(FMAX(left_brake, parking_brake));
 586     FCS->SetRBrake(FMAX(right_brake, parking_brake));
 587
 588
 589     FCS->SetCBrake( 0.0 );
 590     // FCS->SetCBrake( globals->get_controls()->get_brake(2) );
 591
 592     FCS->SetGearCmd( globals->get_controls()->get_gear_down());
 593     for (i = 0; i < Propulsion->GetNumEngines(); i++) {
 594       SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 595
 596       FCS->SetThrottleCmd(i, globals->get_controls()->get_throttle(i));
 597       FCS->SetMixtureCmd(i, globals->get_controls()->get_mixture(i));
 598       FCS->SetPropAdvanceCmd(i, globals->get_controls()->get_prop_advance(i));
 599       FCS->SetFeatherCmd(i, globals->get_controls()->get_feather(i));
 600
 601       switch (Propulsion->GetEngine(i)->GetType()) {
 602       case FGEngine::etPiston:
 603         { // FGPiston code block
 604         FGPiston* eng = (FGPiston*)Propulsion->GetEngine(i);
 605         eng->SetMagnetos( globals->get_controls()->get_magnetos(i) );
 606         break;
 607         } // end FGPiston code block
 608       case FGEngine::etTurbine:
 609         { // FGTurbine code block
 610         FGTurbine* eng = (FGTurbine*)Propulsion->GetEngine(i);
 611         eng->SetAugmentation( globals->get_controls()->get_augmentation(i) );
 612         eng->SetReverse( globals->get_controls()->get_reverser(i) );
 613         //eng->SetInjection( globals->get_controls()->get_water_injection(i) );
 614         eng->SetCutoff( globals->get_controls()->get_cutoff(i) );
 615         eng->SetIgnition( globals->get_controls()->get_ignition(i) );
 616         break;
 617         } // end FGTurbine code block
 618       case FGEngine::etRocket:
 619         { // FGRocket code block
 620         FGRocket* eng = (FGRocket*)Propulsion->GetEngine(i);
 621         break;
 622         } // end FGRocket code block
 623       case FGEngine::etTurboprop:
 624         { // FGTurboProp code block
 625         FGTurboProp* eng = (FGTurboProp*)Propulsion->GetEngine(i);
 626         eng->SetReverse( globals->get_controls()->get_reverser(i) );
 627         eng->SetCutoff( globals->get_controls()->get_cutoff(i) );
 628         eng->SetIgnition( globals->get_controls()->get_ignition(i) );
 629
 630         eng->SetGeneratorPower( globals->get_controls()->get_generator_breaker(i) );
 631         eng->SetCondition( globals->get_controls()->get_condition(i) );
 632         break;
 633         } // end FGTurboProp code block
 634       default:
 635         break;
 636       }
 637
 638       { // FGEngine code block
 639       FGEngine* eng = Propulsion->GetEngine(i);
 640
 641       eng->SetStarter( globals->get_controls()->get_starter(i) );
 642       eng->SetRunning( node->getBoolValue("running") );
 643       } // end FGEngine code block
 644     }
 645
 646
 647     Propagate->SetSeaLevelRadius( get_Sea_level_radius() );
 648
 649     Atmosphere->SetExTemperature(
 650                   9.0/5.0*(temperature->getDoubleValue()+273.15) );
 651     Atmosphere->SetExPressure(pressure->getDoubleValue()*70.726566);
 652     Atmosphere->SetExDensity(density->getDoubleValue());
 653
 654     tmp = turbulence_gain->getDoubleValue();
 655     //Atmosphere->SetTurbGain(tmp * tmp * 100.0);
 656
 657     tmp = turbulence_rate->getDoubleValue();
 658     //Atmosphere->SetTurbRate(tmp);
 659
 660     Atmosphere->SetWindNED( -wind_from_north->getDoubleValue(),
 661                             -wind_from_east->getDoubleValue(),
 662                             -wind_from_down->getDoubleValue() );
 663 //    SG_LOG(SG_FLIGHT,SG_INFO, "Wind NED: "
 664 //                  << get_V_north_airmass() << ", "
 665 //                  << get_V_east_airmass()  << ", "
 666 //                  << get_V_down_airmass() );
 667
 668     for (i = 0; i < Propulsion->GetNumTanks(); i++) {
 669       SGPropertyNode * node = fgGetNode("/consumables/fuel/tank", i, true);
 670       FGTank * tank = Propulsion->GetTank(i);
 671       tank->SetContents(node->getDoubleValue("level-gal_us") * 6.6);
 672 //       tank->SetContents(node->getDoubleValue("level-lbs"));
 673     }
 674
 675     Propulsion->SetFuelFreeze((fgGetNode("/sim/freeze/fuel",true))->getBoolValue());
 676     fdmex->SetChild(slaved->getBoolValue());
 677
 678     return true;
 679 }
 680
 681 /******************************************************************************/
 682
 683 // Convert from the JSBsim generic_ struct to the FGInterface struct
 684
 685 bool FGJSBsim::copy_from_JSBsim()
 686 {
 687     unsigned int i, j;
 688 /*
 689     _set_Inertias( MassBalance->GetMass(),
 690                    MassBalance->GetIxx(),
 691                    MassBalance->GetIyy(),
 692                    MassBalance->GetIzz(),
 693                    MassBalance->GetIxz() );
 694 */
 695     _set_CG_Position( MassBalance->GetXYZcg(1),
 696                       MassBalance->GetXYZcg(2),
 697                       MassBalance->GetXYZcg(3) );
 698
 699     _set_Accels_Body( Aircraft->GetBodyAccel(1),
 700                       Aircraft->GetBodyAccel(2),
 701                       Aircraft->GetBodyAccel(3) );
 702
 703     _set_Accels_CG_Body_N ( Aircraft->GetNcg(1),
 704                             Aircraft->GetNcg(2),
 705                             Aircraft->GetNcg(3) );
 706
 707     _set_Accels_Pilot_Body( Auxiliary->GetPilotAccel(1),
 708                             Auxiliary->GetPilotAccel(2),
 709                             Auxiliary->GetPilotAccel(3) );
 710
 711     _set_Nlf( Aircraft->GetNlf() );
 712
 713     // Velocities
 714
 715     _set_Velocities_Local( Propagate->GetVel(FGJSBBase::eNorth),
 716                            Propagate->GetVel(FGJSBBase::eEast),
 717                            Propagate->GetVel(FGJSBBase::eDown) );
 718
 719     _set_Velocities_Wind_Body( Propagate->GetUVW(1),
 720                                Propagate->GetUVW(2),
 721                                Propagate->GetUVW(3) );
 722
 723     // Make the HUD work ...
 724     _set_Velocities_Ground( Propagate->GetVel(FGJSBBase::eNorth),
 725                             Propagate->GetVel(FGJSBBase::eEast),
 726                             -Propagate->GetVel(FGJSBBase::eDown) );
 727
 728     _set_V_rel_wind( Auxiliary->GetVt() );
 729
 730     _set_V_equiv_kts( Auxiliary->GetVequivalentKTS() );
 731
 732     _set_V_calibrated_kts( Auxiliary->GetVcalibratedKTS() );
 733
 734     _set_V_ground_speed( Auxiliary->GetVground() );
 735
 736     _set_Omega_Body( Propagate->GetPQR(FGJSBBase::eP),
 737                      Propagate->GetPQR(FGJSBBase::eQ),
 738                      Propagate->GetPQR(FGJSBBase::eR) );
 739
 740     _set_Euler_Rates( Auxiliary->GetEulerRates(FGJSBBase::ePhi),
 741                       Auxiliary->GetEulerRates(FGJSBBase::eTht),
 742                       Auxiliary->GetEulerRates(FGJSBBase::ePsi) );
 743
 744     _set_Mach_number( Auxiliary->GetMach() );
 745
 746     // Positions of Visual Reference Point
 747     FGLocation l = Auxiliary->GetLocationVRP();
 748     _updateGeocentricPosition( l.GetLatitude(), l.GetLongitude(),
 749                                l.GetRadius() - get_Sea_level_radius() );
 750
 751     _set_Altitude_AGL( Propagate->GetDistanceAGL() );
 752     {
 753       double loc_cart[3] = { l(FGJSBBase::eX), l(FGJSBBase::eY), l(FGJSBBase::eZ) };
 754       double contact[3], d[3], sd, t;
 755       is_valid_m(&t, d, &sd);
 756       get_agl_ft(t, loc_cart, SG_METER_TO_FEET*2, contact, d, d, d, &sd);
 757       double rwrad
 758         = FGColumnVector3( contact[0], contact[1], contact[2] ).Magnitude();
 759       _set_Runway_altitude( rwrad - get_Sea_level_radius() );
 760     }
 761
 762     _set_Euler_Angles( Propagate->GetEuler(FGJSBBase::ePhi),
 763                        Propagate->GetEuler(FGJSBBase::eTht),
 764                        Propagate->GetEuler(FGJSBBase::ePsi) );
 765
 766     _set_Alpha( Auxiliary->Getalpha() );
 767     _set_Beta( Auxiliary->Getbeta() );
 768
 769
 770     _set_Gamma_vert_rad( Auxiliary->GetGamma() );
 771
 772     _set_Earth_position_angle( Inertial->GetEarthPositionAngle() );
 773
 774     _set_Climb_Rate( Propagate->Gethdot() );
 775
 776     const FGMatrix33& Tl2b = Propagate->GetTl2b();
 777     for ( i = 1; i <= 3; i++ ) {
 778         for ( j = 1; j <= 3; j++ ) {
 779             _set_T_Local_to_Body( i, j, Tl2b(i,j) );
 780         }
 781     }
 782
 783     // Copy the engine values from JSBSim.
 784     for ( i=0; i < Propulsion->GetNumEngines(); i++ ) {
 785       SGPropertyNode * node = fgGetNode("engines/engine", i, true);
 786       SGPropertyNode * tnode = node->getChild("thruster", 0, true);
 787       FGThruster * thruster = Propulsion->GetEngine(i)->GetThruster();
 788
 789       switch (Propulsion->GetEngine(i)->GetType()) {
 790       case FGEngine::etPiston:
 791         { // FGPiston code block
 792         FGPiston* eng = (FGPiston*)Propulsion->GetEngine(i);
 793         node->setDoubleValue("egt-degf", eng->getExhaustGasTemp_degF());
 794         node->setDoubleValue("oil-temperature-degf", eng->getOilTemp_degF());
 795         node->setDoubleValue("oil-pressure-psi", eng->getOilPressure_psi());
 796         node->setDoubleValue("mp-osi", eng->getManifoldPressure_inHg());
 797         // NOTE: mp-osi is not in ounces per square inch.
 798         // This error is left for reasons of backwards compatibility with
 799         // existing FlightGear sound and instrument configurations.
 800         node->setDoubleValue("mp-inhg", eng->getManifoldPressure_inHg());
 801         node->setDoubleValue("cht-degf", eng->getCylinderHeadTemp_degF());
 802         node->setDoubleValue("rpm", eng->getRPM());
 803         } // end FGPiston code block
 804         break;
 805       case FGEngine::etRocket:
 806         { // FGRocket code block
 807         FGRocket* eng = (FGRocket*)Propulsion->GetEngine(i);
 808         } // end FGRocket code block
 809         break;
 810       case FGEngine::etTurbine:
 811         { // FGTurbine code block
 812         FGTurbine* eng = (FGTurbine*)Propulsion->GetEngine(i);
 813         node->setDoubleValue("n1", eng->GetN1());
 814         node->setDoubleValue("n2", eng->GetN2());
 815         node->setDoubleValue("egt-degf", 32 + eng->GetEGT()*9/5);
 816         node->setBoolValue("augmentation", eng->GetAugmentation());
 817         node->setBoolValue("water-injection", eng->GetInjection());
 818         node->setBoolValue("ignition", eng->GetIgnition());
 819         node->setDoubleValue("nozzle-pos-norm", eng->GetNozzle());
 820         node->setDoubleValue("inlet-pos-norm", eng->GetInlet());
 821         node->setDoubleValue("oil-pressure-psi", eng->getOilPressure_psi());
 822         node->setBoolValue("reversed", eng->GetReversed());
 823         node->setBoolValue("cutoff", eng->GetCutoff());
 824         node->setDoubleValue("epr", eng->GetEPR());
 825         globals->get_controls()->set_reverser(i, eng->GetReversed() );
 826         globals->get_controls()->set_cutoff(i, eng->GetCutoff() );
 827         globals->get_controls()->set_water_injection(i, eng->GetInjection() );
 828         globals->get_controls()->set_augmentation(i, eng->GetAugmentation() );
 829         } // end FGTurbine code block
 830         break;
 831       case FGEngine::etTurboprop:
 832         { // FGTurboProp code block
 833         FGTurboProp* eng = (FGTurboProp*)Propulsion->GetEngine(i);
 834         node->setDoubleValue("n1", eng->GetN1());
 835         //node->setDoubleValue("n2", eng->GetN2());
 836         node->setDoubleValue("itt_degf", 32 + eng->GetITT()*9/5);
 837         node->setBoolValue("ignition", eng->GetIgnition());
 838         node->setDoubleValue("nozzle-pos-norm", eng->GetNozzle());
 839         node->setDoubleValue("inlet-pos-norm", eng->GetInlet());
 840         node->setDoubleValue("oil-pressure-psi", eng->getOilPressure_psi());
 841         node->setBoolValue("reversed", eng->GetReversed());
 842         node->setBoolValue("cutoff", eng->GetCutoff());
 843         node->setBoolValue("starting", eng->GetEngStarting());
 844         node->setBoolValue("generator-power", eng->GetGeneratorPower());
 845         node->setBoolValue("damaged", eng->GetCondition());
 846         node->setBoolValue("ielu-intervent", eng->GetIeluIntervent());
 847         node->setDoubleValue("oil-temperature-degf", eng->getOilTemp_degF());
 848 //        node->setBoolValue("onfire", eng->GetFire());
 849         globals->get_controls()->set_reverser(i, eng->GetReversed() );
 850         globals->get_controls()->set_cutoff(i, eng->GetCutoff() );
 851         } // end FGTurboProp code block
 852         break;
 853       case FGEngine::etElectric:
 854         { // FGElectric code block
 855         FGElectric* eng = (FGElectric*)Propulsion->GetEngine(i);
 856         node->setDoubleValue("rpm", eng->getRPM());
 857         } // end FGElectric code block
 858         break;
 859       case FGEngine::etUnknown:
 860         break;
 861       }
 862
 863       { // FGEngine code block
 864       FGEngine* eng = Propulsion->GetEngine(i);
 865       node->setDoubleValue("fuel-flow-gph", eng->getFuelFlow_gph());
 866       node->setDoubleValue("thrust_lb", thruster->GetThrust());
 867       node->setDoubleValue("fuel-flow_pph", eng->getFuelFlow_pph());
 868       node->setBoolValue("running", eng->GetRunning());
 869       node->setBoolValue("starter", eng->GetStarter());
 870       node->setBoolValue("cranking", eng->GetCranking());
 871       globals->get_controls()->set_starter(i, eng->GetStarter() );
 872       } // end FGEngine code block
 873
 874       switch (thruster->GetType()) {
 875       case FGThruster::ttNozzle:
 876         { // FGNozzle code block
 877         FGNozzle* noz = (FGNozzle*)thruster;
 878         } // end FGNozzle code block
 879         break;
 880       case FGThruster::ttPropeller:
 881         { // FGPropeller code block
 882         FGPropeller* prop = (FGPropeller*)thruster;
 883         tnode->setDoubleValue("rpm", thruster->GetRPM());
 884         tnode->setDoubleValue("pitch", prop->GetPitch());
 885         tnode->setDoubleValue("torque", prop->GetTorque());
 886         tnode->setBoolValue("feathered", prop->GetFeather());
 887         } // end FGPropeller code block
 888         break;
 889       case FGThruster::ttRotor:
 890         { // FGRotor code block
 891         FGRotor* rotor = (FGRotor*)thruster;
 892         } // end FGRotor code block
 893         break;
 894       case FGThruster::ttDirect:
 895         { // Direct code block
 896         } // end Direct code block
 897         break;
 898       }
 899
 900     }
 901
 902     // Copy the fuel levels from JSBSim if fuel
 903     // freeze not enabled.
 904     if ( ! Propulsion->GetFuelFreeze() ) {
 905       for (i = 0; i < Propulsion->GetNumTanks(); i++) {
 906         SGPropertyNode * node = fgGetNode("/consumables/fuel/tank", i, true);
 907         FGTank* tank = Propulsion->GetTank(i);
 908         double contents = tank->GetContents();
 909         double temp = tank->GetTemperature_degC();
 910         node->setDoubleValue("level-gal_us", contents/6.6);
 911         node->setDoubleValue("level-lbs", contents);
 912         if (temp != -9999.0) node->setDoubleValue("temperature_degC", temp);
 913       }
 914     }
 915
 916     update_gear();
 917
 918     stall_warning->setDoubleValue( Aerodynamics->GetStallWarn() );
 919
 920     elevator_pos_pct->setDoubleValue( FCS->GetDePos(ofNorm) );
 921     left_aileron_pos_pct->setDoubleValue( FCS->GetDaLPos(ofNorm) );
 922     right_aileron_pos_pct->setDoubleValue( FCS->GetDaRPos(ofNorm) );
 923     rudder_pos_pct->setDoubleValue( -1*FCS->GetDrPos(ofNorm) );
 924     flap_pos_pct->setDoubleValue( FCS->GetDfPos(ofNorm) );
 925     speedbrake_pos_pct->setDoubleValue( FCS->GetDsbPos(ofNorm) );
 926     spoilers_pos_pct->setDoubleValue( FCS->GetDspPos(ofNorm) );
 927     tailhook_pos_pct->setDoubleValue( FCS->GetTailhookPos() );
 928     wing_fold_pos_pct->setDoubleValue( FCS->GetWingFoldPos() );
 929
 930     // force a sim crashed if crashed (altitude AGL < 0)
 931     if (get_Altitude_AGL() < -100.0) {
 932          fdmex->SuspendIntegration();
 933          crashed = true;
 934     }
 935
 936     return true;
 937 }
 938
 939
 940 bool FGJSBsim::ToggleDataLogging(void)
 941 {
 942   // ToDo: handle this properly
 943   fdmex->DisableOutput();
 944   return false;
 945 }
 946
 947
 948 bool FGJSBsim::ToggleDataLogging(bool state)
 949 {
 950     if (state) {
 951       fdmex->EnableOutput();
 952       return true;
 953     } else {
 954       fdmex->DisableOutput();
 955       return false;
 956     }
 957 }
 958
 959
 960 //Positions
 961 void FGJSBsim::set_Latitude(double lat)
 962 {
 963     static SGConstPropertyNode_ptr altitude = fgGetNode("/position/altitude-ft");
 964     double alt;
 965     double sea_level_radius_meters, lat_geoc;
 966
 967     // In case we're not trimming
 968     FGInterface::set_Latitude(lat);
 969
 970     if ( altitude->getDoubleValue() > -9990 ) {
 971       alt = altitude->getDoubleValue();
 972     } else {
 973       alt = 0.0;
 974     }
 975
 976     update_ic();
 977     SG_LOG(SG_FLIGHT,SG_INFO,"FGJSBsim::set_Latitude: " << lat );
 978     SG_LOG(SG_FLIGHT,SG_INFO," cur alt (ft) =  " << alt );
 979
 980     sgGeodToGeoc( lat, alt * SG_FEET_TO_METER,
 981                       &sea_level_radius_meters, &lat_geoc );
 982     _set_Sea_level_radius( sea_level_radius_meters * SG_METER_TO_FEET  );
 983     fgic->SetSeaLevelRadiusFtIC( sea_level_radius_meters * SG_METER_TO_FEET  );
 984     fgic->SetLatitudeRadIC( lat_geoc );
 985     needTrim=true;
 986 }
 987
 988
 989 void FGJSBsim::set_Longitude(double lon)
 990 {
 991     SG_LOG(SG_FLIGHT,SG_INFO,"FGJSBsim::set_Longitude: " << lon );
 992
 993     // In case we're not trimming
 994     FGInterface::set_Longitude(lon);
 995
 996     update_ic();
 997     fgic->SetLongitudeRadIC( lon );
 998     needTrim=true;
 999 }
1000
1001 // Sets the altitude above sea level.
1002 void FGJSBsim::set_Altitude(double alt)
1003 {
1004     static SGConstPropertyNode_ptr latitude = fgGetNode("/position/latitude-deg");
1005
1006     double sea_level_radius_meters,lat_geoc;
1007
1008     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Altitude: " << alt );
1009     SG_LOG(SG_FLIGHT,SG_INFO, "  lat (deg) = " << latitude->getDoubleValue() );
1010
1011     // In case we're not trimming
1012     FGInterface::set_Altitude(alt);
1013
1014     update_ic();
1015     sgGeodToGeoc( latitude->getDoubleValue() * SGD_DEGREES_TO_RADIANS, alt,
1016                   &sea_level_radius_meters, &lat_geoc);
1017     _set_Sea_level_radius( sea_level_radius_meters * SG_METER_TO_FEET  );
1018     fgic->SetSeaLevelRadiusFtIC( sea_level_radius_meters * SG_METER_TO_FEET );
1019     SG_LOG(SG_FLIGHT, SG_INFO,
1020           "Terrain elevation: " << FGInterface::get_Runway_altitude() * SG_METER_TO_FEET );
1021     fgic->SetLatitudeRadIC( lat_geoc );
1022     fgic->SetAltitudeASLFtIC(alt);
1023     needTrim=true;
1024 }
1025
1026 void FGJSBsim::set_V_calibrated_kts(double vc)
1027 {
1028     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_V_calibrated_kts: " <<  vc );
1029
1030     // In case we're not trimming
1031     FGInterface::set_V_calibrated_kts(vc);
1032
1033     update_ic();
1034     fgic->SetVcalibratedKtsIC(vc);
1035     needTrim=true;
1036 }
1037
1038 void FGJSBsim::set_Mach_number(double mach)
1039 {
1040     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Mach_number: " <<  mach );
1041
1042     // In case we're not trimming
1043     FGInterface::set_Mach_number(mach);
1044
1045     update_ic();
1046     fgic->SetMachIC(mach);
1047     needTrim=true;
1048 }
1049
1050 void FGJSBsim::set_Velocities_Local( double north, double east, double down )
1051 {
1052     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Velocities_Local: "
1053        << north << ", " <<  east << ", " << down );
1054
1055     // In case we're not trimming
1056     FGInterface::set_Velocities_Local(north, east, down);
1057
1058     update_ic();
1059     fgic->SetVNorthFpsIC(north);
1060     fgic->SetVEastFpsIC(east);
1061     fgic->SetVDownFpsIC(down);
1062     needTrim=true;
1063 }
1064
1065 void FGJSBsim::set_Velocities_Wind_Body( double u, double v, double w)
1066 {
1067     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Velocities_Wind_Body: "
1068        << u << ", " <<  v << ", " <<  w );
1069
1070     // In case we're not trimming
1071     FGInterface::set_Velocities_Wind_Body(u, v, w);
1072
1073     update_ic();
1074     fgic->SetUBodyFpsIC(u);
1075     fgic->SetVBodyFpsIC(v);
1076     fgic->SetWBodyFpsIC(w);
1077     needTrim=true;
1078 }
1079
1080 //Euler angles
1081 void FGJSBsim::set_Euler_Angles( double phi, double theta, double psi )
1082 {
1083     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Euler_Angles: "
1084        << phi << ", " << theta << ", " << psi );
1085
1086     // In case we're not trimming
1087     FGInterface::set_Euler_Angles(phi, theta, psi);
1088
1089     update_ic();
1090     fgic->SetThetaRadIC(theta);
1091     fgic->SetPhiRadIC(phi);
1092     fgic->SetPsiRadIC(psi);
1093     needTrim=true;
1094 }
1095
1096 //Flight Path
1097 void FGJSBsim::set_Climb_Rate( double roc)
1098 {
1099     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Climb_Rate: " << roc );
1100
1101     // In case we're not trimming
1102     FGInterface::set_Climb_Rate(roc);
1103
1104     update_ic();
1105     //since both climb rate and flight path angle are set in the FG
1106     //startup sequence, something is needed to keep one from cancelling
1107     //out the other.
1108     if( !(fabs(roc) > 1 && fabs(fgic->GetFlightPathAngleRadIC()) < 0.01) ) {
1109       fgic->SetClimbRateFpsIC(roc);
1110     }
1111     needTrim=true;
1112 }
1113
1114 void FGJSBsim::set_Gamma_vert_rad( double gamma)
1115 {
1116     SG_LOG(SG_FLIGHT,SG_INFO, "FGJSBsim::set_Gamma_vert_rad: " << gamma );
1117
1118     update_ic();
1119     if( !(fabs(gamma) < 0.01 && fabs(fgic->GetClimbRateFpsIC()) > 1) ) {
1120       fgic->SetFlightPathAngleRadIC(gamma);
1121     }
1122     needTrim=true;
1123 }
1124
1125 void FGJSBsim::init_gear(void )
1126 {
1127     FGGroundReactions* gr=fdmex->GetGroundReactions();
1128     int Ngear=GroundReactions->GetNumGearUnits();
1129     for (int i=0;i<Ngear;i++) {
1130       FGLGear *gear = gr->GetGearUnit(i);
1131       SGPropertyNode * node = fgGetNode("gear/gear", i, true);
1132       node->setDoubleValue("xoffset-in", gear->GetBodyLocation()(1));
1133       node->setDoubleValue("yoffset-in", gear->GetBodyLocation()(2));
1134       node->setDoubleValue("zoffset-in", gear->GetBodyLocation()(3));
1135       node->setBoolValue("wow", gear->GetWOW());
1136       node->setDoubleValue("rollspeed-ms", gear->GetWheelRollVel()*0.3043);
1137       node->setBoolValue("has-brake", gear->GetBrakeGroup() > 0);
1138       node->setDoubleValue("position-norm", gear->GetGearUnitPos());
1139       node->setDoubleValue("tire-pressure-norm", gear->GetTirePressure());
1140       node->setDoubleValue("compression-norm", gear->GetCompLen());
1141       node->setDoubleValue("compression-ft", gear->GetCompLen());
1142       if ( gear->GetSteerable() )
1143         node->setDoubleValue("steering-norm", gear->GetSteerNorm());
1144     }
1145 }
1146
1147 void FGJSBsim::update_gear(void)
1148 {
1149     FGGroundReactions* gr=fdmex->GetGroundReactions();
1150     int Ngear=GroundReactions->GetNumGearUnits();
1151     for (int i=0;i<Ngear;i++) {
1152       FGLGear *gear = gr->GetGearUnit(i);
1153       SGPropertyNode * node = fgGetNode("gear/gear", i, true);
1154       node->getChild("wow", 0, true)->setBoolValue( gear->GetWOW());
1155       node->getChild("rollspeed-ms", 0, true)->setDoubleValue(gear->GetWheelRollVel()*0.3043);
1156       node->getChild("position-norm", 0, true)->setDoubleValue(gear->GetGearUnitPos());
1157       gear->SetTirePressure(node->getDoubleValue("tire-pressure-norm"));
1158       node->setDoubleValue("compression-norm", gear->GetCompLen());
1159       node->setDoubleValue("compression-ft", gear->GetCompLen());
1160       if ( gear->GetSteerable() )
1161         node->setDoubleValue("steering-norm", gear->GetSteerNorm());
1162     }
1163 }
1164
1165 void FGJSBsim::do_trim(void)
1166 {
1167   FGTrim *fgtrim;
1168
1169   if ( fgGetBool("/sim/presets/onground") )
1170   {
1171     fgtrim = new FGTrim(fdmex,tGround);
1172   } else {
1173     fgtrim = new FGTrim(fdmex,tLongitudinal);
1174   }
1175
1176   if ( !fgtrim->DoTrim() ) {
1177     fgtrim->Report();
1178     fgtrim->TrimStats();
1179   } else {
1180     trimmed->setBoolValue(true);
1181   }
1182   delete fgtrim;
1183
1184   pitch_trim->setDoubleValue( FCS->GetPitchTrimCmd() );
1185   throttle_trim->setDoubleValue( FCS->GetThrottleCmd(0) );
1186   aileron_trim->setDoubleValue( FCS->GetDaCmd() );
1187   rudder_trim->setDoubleValue( FCS->GetDrCmd() );
1188
1189   globals->get_controls()->set_elevator_trim(FCS->GetPitchTrimCmd());
1190   globals->get_controls()->set_elevator(FCS->GetDeCmd());
1191   globals->get_controls()->set_throttle(FGControls::ALL_ENGINES,
1192   FCS->GetThrottleCmd(0));
1193
1194   globals->get_controls()->set_aileron(FCS->GetDaCmd());
1195   globals->get_controls()->set_rudder( FCS->GetDrCmd());
1196
1197   SG_LOG( SG_FLIGHT, SG_INFO, "  Trim complete" );
1198 }
1199
1200 void FGJSBsim::update_ic(void)
1201 {
1202    if ( !needTrim ) {
1203      fgic->SetLatitudeRadIC(get_Lat_geocentric() );
1204      fgic->SetLongitudeRadIC( get_Longitude() );
1205      fgic->SetAltitudeASLFtIC( get_Altitude() );
1206      fgic->SetVcalibratedKtsIC( get_V_calibrated_kts() );
1207      fgic->SetThetaRadIC( get_Theta() );
1208      fgic->SetPhiRadIC( get_Phi() );
1209      fgic->SetPsiRadIC( get_Psi() );
1210      fgic->SetClimbRateFpsIC( get_Climb_Rate() );
1211    }
1212 }
1213
1214 bool
1215 FGJSBsim::get_agl_ft(double t, const double pt[3], double alt_off,
1216                      double contact[3], double normal[3], double vel[3],
1217                      double angularVel[3], double *agl)
1218 {
1219    const SGMaterial* material;
1220    simgear::BVHNode::Id id;
1221    if (!FGInterface::get_agl_ft(t, pt, alt_off, contact, normal, vel,
1222                                 angularVel, material, id))
1223        return false;
1224    SGGeod geodPt = SGGeod::fromCart(SG_FEET_TO_METER*SGVec3d(pt));
1225    SGQuatd hlToEc = SGQuatd::fromLonLat(geodPt);
1226    *agl = dot(hlToEc.rotate(SGVec3d(0, 0, 1)), SGVec3d(contact) - SGVec3d(pt));
1227    return true;
1228 }
1229
1230 inline static double dot3(const FGColumnVector3& a, const FGColumnVector3& b)
1231 {
1232     return a(1) * b(1) + a(2) * b(2) + a(3) * b(3);
1233 }
1234
1235 inline static double sqr(double x)
1236 {
1237     return x * x;
1238 }
1239
1240 static double angle_diff(double a, double b)
1241 {
1242     double diff = fabs(a - b);
1243     if (diff > 180) diff = 360 - diff;
1244
1245     return diff;
1246 }
1247
1248 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)
1249 {
1250     FGColumnVector3 tip(-hook_length * cos_fi_guess, 0, hook_length * sin_fi_guess);
1251     double dist = dot3(tip, ground_normal_body);
1252     if (fabs(dist + E) < 0.0001) {
1253         sin_fis[*points] = sin_fi_guess;
1254         cos_fis[*points] = cos_fi_guess;
1255         fis[*points] = atan2(sin_fi_guess, cos_fi_guess) * SG_RADIANS_TO_DEGREES;
1256         (*points)++;
1257     }
1258 }
1259
1260
1261 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)
1262 {
1263     if (sin_fi_guess >= -1 && sin_fi_guess <= 1) {
1264         double cos_fi_guess = sqrt(1 - sqr(sin_fi_guess));
1265         check_hook_solution(ground_normal_body, E, hook_length, sin_fi_guess, cos_fi_guess, sin_fis, cos_fis, fis, points);
1266         if (fabs(cos_fi_guess) > SG_EPSILON) {
1267             check_hook_solution(ground_normal_body, E, hook_length, sin_fi_guess, -cos_fi_guess, sin_fis, cos_fis, fis, points);
1268         }
1269     }
1270 }
1271
1272 void FGJSBsim::update_external_forces(double t_off)
1273 {
1274     const FGMatrix33& Tb2l = Propagate->GetTb2l();
1275     const FGMatrix33& Tl2b = Propagate->GetTl2b();
1276     const FGLocation& Location = Propagate->GetLocation();
1277     const FGMatrix33& Tec2l = Location.GetTec2l();
1278
1279     double hook_area[4][3];
1280
1281     FGColumnVector3 hook_root_body = MassBalance->StructuralToBody(hook_root_struct);
1282     FGColumnVector3 hook_root = Location.LocalToLocation(Tb2l *   hook_root_body);
1283     hook_area[1][0] = hook_root(1);
1284     hook_area[1][1] = hook_root(2);
1285     hook_area[1][2] = hook_root(3);
1286
1287     hook_length = fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-length-ft", 6.75);
1288     double fi_min = fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-min-deg", -18);
1289     double fi_max = fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-max-deg", 30);
1290     double fi = fgGetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-norm") * (fi_max - fi_min) + fi_min;
1291     double cos_fi = cos(fi * SG_DEGREES_TO_RADIANS);
1292     double sin_fi = sin(fi * SG_DEGREES_TO_RADIANS);
1293
1294     FGColumnVector3 hook_tip_body = hook_root_body;
1295     hook_tip_body(1) -= hook_length * cos_fi;
1296     hook_tip_body(3) += hook_length * sin_fi;
1297
1298     double contact[3];
1299     double ground_normal[3];
1300     double ground_vel[3];
1301     double ground_angular_vel[3];
1302     double root_agl_ft;
1303
1304     if (!got_wire) {
1305         bool got = get_agl_ft(t_off, hook_area[1], 0, contact, ground_normal,
1306                               ground_vel, ground_angular_vel, &root_agl_ft);
1307         if (got && root_agl_ft > 0 && root_agl_ft < hook_length) {
1308             FGColumnVector3 ground_normal_body = Tl2b * (Tec2l * FGColumnVector3(ground_normal[0], ground_normal[1], ground_normal[2]));
1309             FGColumnVector3 contact_body = Tl2b * Location.LocationToLocal(FGColumnVector3(contact[0], contact[1], contact[2]));
1310             double D = -dot3(contact_body, ground_normal_body);
1311
1312             // check hook tip agl against same ground plane
1313             double hook_tip_agl_ft = dot3(hook_tip_body, ground_normal_body) + D;
1314             if (hook_tip_agl_ft < 0) {
1315
1316                 // hook tip: hx - l cos, hy, hz + l sin
1317                 // on ground:  - n0 l cos + n2 l sin + E = 0
1318
1319                 double E = D + dot3(hook_root_body, ground_normal_body);
1320
1321                 // substitue x = sin fi, cos fi = sqrt(1 - x * x)
1322                 // and rearrange to get a quadratic with coeffs:
1323                 double a = sqr(hook_length) * (sqr(ground_normal_body(1)) + sqr(ground_normal_body(3)));
1324                 double b = 2 * E * ground_normal_body(3) * hook_length;
1325                 double c = sqr(E) - sqr(ground_normal_body(1) * hook_length);
1326
1327                 double disc = sqr(b) - 4 * a * c;
1328                 if (disc >= 0) {
1329                     double delta = sqrt(disc) / (2 * a);
1330
1331                     // allow 4 solutions for safety, should never happen
1332                     double sin_fis[4];
1333                     double cos_fis[4];
1334                     double fis[4];
1335                     int points = 0;
1336
1337                     double sin_fi_guess = -b / (2 * a) - delta;
1338                     check_hook_solution(ground_normal_body, E, hook_length, sin_fi_guess, sin_fis, cos_fis, fis, &points);
1339                     check_hook_solution(ground_normal_body, E, hook_length, sin_fi_guess + 2 * delta, sin_fis, cos_fis, fis, &points);
1340
1341                     if (points == 2) {
1342                         double diff1 = angle_diff(fi, fis[0]);
1343                         double diff2 = angle_diff(fi, fis[1]);
1344                         int point = diff1 < diff2 ? 0 : 1;
1345                         fi = fis[point];
1346                         sin_fi = sin_fis[point];
1347                         cos_fi = cos_fis[point];
1348                         hook_tip_body(1) = hook_root_body(1) - hook_length * cos_fi;
1349                         hook_tip_body(3) = hook_root_body(3) + hook_length * sin_fi;
1350                     }
1351                 }
1352             }
1353         }
1354     } else {
1355         FGColumnVector3 hook_root_vel = Propagate->GetVel() + (Tb2l * (Propagate->GetPQR() *  hook_root_body));
1356         double wire_ends_ec[2][3];
1357         double wire_vel_ec[2][3];
1358         get_wire_ends_ft(t_off, wire_ends_ec, wire_vel_ec);
1359         FGColumnVector3 wire_vel_1 = Tec2l * FGColumnVector3(wire_vel_ec[0][0], wire_vel_ec[0][1], wire_vel_ec[0][2]);
1360         FGColumnVector3 wire_vel_2 = Tec2l * FGColumnVector3(wire_vel_ec[1][0], wire_vel_ec[1][1], wire_vel_ec[1][2]);
1361         FGColumnVector3 rel_vel = hook_root_vel - (wire_vel_1 + wire_vel_2) / 2;
1362         if (rel_vel.Magnitude() < 3) {
1363             got_wire = false;
1364             release_wire();
1365             fgSetDouble("/fdm/jsbsim/external_reactions/hook/magnitude", 0.0);
1366         } else {
1367             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;
1368             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;
1369             FGColumnVector3 force_plane_normal = wire_end1_body * wire_end2_body;
1370             force_plane_normal.Normalize();
1371             cos_fi = dot3(force_plane_normal, FGColumnVector3(0, 0, 1));
1372             if (cos_fi < 0) cos_fi = -cos_fi;
1373             sin_fi = sqrt(1 - sqr(cos_fi));
1374             fi = atan2(sin_fi, cos_fi) * SG_RADIANS_TO_DEGREES;
1375
1376             fgSetDouble("/fdm/jsbsim/external_reactions/hook/x", -cos_fi);
1377             fgSetDouble("/fdm/jsbsim/external_reactions/hook/y", 0);
1378             fgSetDouble("/fdm/jsbsim/external_reactions/hook/z", sin_fi);
1379             fgSetDouble("/fdm/jsbsim/external_reactions/hook/magnitude", fgGetDouble("/fdm/jsbsim/systems/hook/force"));
1380         }
1381     }
1382
1383     FGColumnVector3 hook_tip = Location.LocalToLocation(Tb2l * hook_tip_body);
1384
1385     hook_area[0][0] = hook_tip(1);
1386     hook_area[0][1] = hook_tip(2);
1387     hook_area[0][2] = hook_tip(3);
1388
1389     if (!got_wire) {
1390         // The previous positions.
1391         hook_area[2][0] = last_hook_root[0];
1392         hook_area[2][1] = last_hook_root[1];
1393         hook_area[2][2] = last_hook_root[2];
1394         hook_area[3][0] = last_hook_tip[0];
1395         hook_area[3][1] = last_hook_tip[1];
1396         hook_area[3][2] = last_hook_tip[2];
1397
1398         // Check if we caught a wire.
1399         // Returns true if we caught one.
1400         if (caught_wire_ft(t_off, hook_area)) {
1401                 got_wire = true;
1402         }
1403     }
1404
1405     // save actual position as old position ...
1406     last_hook_tip[0] = hook_area[0][0];
1407     last_hook_tip[1] = hook_area[0][1];
1408     last_hook_tip[2] = hook_area[0][2];
1409     last_hook_root[0] = hook_area[1][0];
1410     last_hook_root[1] = hook_area[1][1];
1411     last_hook_root[2] = hook_area[1][2];
1412
1413     fgSetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-deg", fi);
1414 }
1415
1416 void FGJSBsim::resetPropertyState()
1417 {
1418 // this code works-around bug #222:
1419 // http://code.google.com/p/flightgear-bugs/issues/detail?id=222
1420 // for whatever reason, having an existing value for the WOW
1421 // property causes the NaNs. Should that be fixed, this code can die
1422   SGPropertyNode* gear = fgGetNode("/fdm/jsbsim/gear", false);
1423   if (!gear) {
1424     return;
1425   }
1426
1427   int index = 0;
1428   SGPropertyNode* unitNode = NULL;
1429   for (; (unitNode = gear->getChild("unit", index)) != NULL; ++index) {
1430     unitNode->removeChild("WOW", 0, false);
1431   }
1432 }
1433