src/FDM/flight.cxx

   1 // flight.cxx -- a general interface to the various flight models
   2 //
   3 // Written by Curtis Olson, started May 1997.
   4 //
   5 // Copyright (C) 1997  Curtis L. Olson  - http://www.flightgear.org/~curt
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20 //
  21 // $Id$
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include "config.h"
  25 #endif
  26
  27 #include "flight.hxx"
  28
  29 #include <simgear/constants.h>
  30 #include <simgear/debug/logstream.hxx>
  31 #include <simgear/timing/timestamp.hxx>
  32 #include <simgear/scene/material/mat.hxx>
  33 #include <simgear/io/iochannel.hxx>
  34
  35 #include <Scenery/scenery.hxx>
  36 #include <Main/globals.hxx>
  37 #include <Main/fg_props.hxx>
  38 #include <FDM/groundcache.hxx>
  39
  40
  41 static inline void assign(double* ptr, const SGVec3d& vec)
  42 {
  43   ptr[0] = vec[0];
  44   ptr[1] = vec[1];
  45   ptr[2] = vec[2];
  46 }
  47
  48 // Constructor
  49 FGInterface::FGInterface()
  50 {
  51     _setup();
  52 }
  53
  54 FGInterface::FGInterface( double dt )
  55 {
  56     _setup();
  57 }
  58
  59 // Destructor
  60 FGInterface::~FGInterface() {
  61     // unbind();                   // FIXME: should be called explicitly
  62 }
  63
  64 int
  65 FGInterface::_calc_multiloop (double dt)
  66 {
  67   // Since some time the simulation time increments we get here are
  68   // already a multiple of the basic update frequency.
  69   // So, there is no need to do our own multiloop rounding with all bad
  70   // roundoff problems when we already have nearly accurate values.
  71   // Only the speedup thing must be still handled here
  72   int hz = fgGetInt("/sim/model-hz");
  73   double speedup = fgGetDouble("/sim/speed-up");
  74   double loops = dt * hz * speedup + delta_loops;
  75   int iloops = SGMiscd::roundToInt(loops);
  76   delta_loops = loops-iloops; // delta_loops required for speed-ups < 1 (to do one iteration every n-th step)
  77   return iloops;
  78 }
  79
  80
  81 /**
  82  * Set default values for the state of the FDM.
  83  *
  84  * This method is invoked by the constructors.
  85  */
  86 void
  87 FGInterface::_setup ()
  88 {
  89     inited = false;
  90     bound = false;
  91
  92     _state.d_cg_rp_body_v = SGVec3d::zeros();
  93     _state.v_dot_local_v = SGVec3d::zeros();
  94     _state.v_dot_body_v = SGVec3d::zeros();
  95     _state.a_cg_body_v = SGVec3d::zeros();
  96     _state.a_pilot_body_v = SGVec3d::zeros();
  97     _state.n_cg_body_v = SGVec3d::zeros();
  98     _state.v_local_v = SGVec3d::zeros();
  99     _state.v_local_rel_ground_v = SGVec3d::zeros();
 100     _state.v_local_airmass_v = SGVec3d::zeros();
 101     _state.v_body_v = SGVec3d::zeros();
 102     _state.omega_body_v = SGVec3d::zeros();
 103     _state.euler_rates_v = SGVec3d::zeros();
 104     _state.geocentric_rates_v = SGVec3d::zeros();
 105     _state.geodetic_position_v = SGGeod::fromRadM(0, 0, 0);
 106     _state.cartesian_position_v = SGVec3d::fromGeod(_state.geodetic_position_v);
 107     _state.geocentric_position_v = SGGeoc::fromCart(_state.cartesian_position_v);
 108     _state.euler_angles_v = SGVec3d::zeros();
 109
 110     _state.nlf=0;
 111     _state.v_rel_wind=_state.v_true_kts=0;
 112     _state.v_ground_speed=_state.v_equiv_kts=0;
 113     _state.v_calibrated_kts=0;
 114     _state.alpha=_state.beta=0;
 115     _state.gamma_vert_rad=0;
 116     _state.density=_state.mach_number=0;
 117     _state.static_pressure=_state.total_pressure=0;
 118     _state.dynamic_pressure=0;
 119     _state.static_temperature=_state.total_temperature=0;
 120     _state.sea_level_radius=_state.earth_position_angle=0;
 121     _state.runway_altitude=0;
 122     _state.climb_rate=0;
 123     _state.altitude_agl=0;
 124     _state.track=0;
 125
 126     delta_loops = 0.0;
 127 }
 128
 129 void
 130 FGInterface::init () {}
 131
 132 /**
 133  * Initialize the state of the FDM.
 134  *
 135  * Subclasses of FGInterface may do their own, additional initialization,
 136  * but there is some that is common to all.  Normally, they should call
 137  * this before they begin their own init to make sure the basic structures
 138  * are set up properly.
 139  */
 140 void
 141 FGInterface::common_init ()
 142 {
 143     SG_LOG( SG_FLIGHT, SG_INFO, "Start common FDM init" );
 144
 145     set_inited( true );
 146
 147     ground_cache.set_cache_time_offset(globals->get_sim_time_sec());
 148
 149     // Set initial position
 150     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing position..." );
 151     double lon = fgGetDouble("/sim/presets/longitude-deg")
 152       * SGD_DEGREES_TO_RADIANS;
 153     double lat = fgGetDouble("/sim/presets/latitude-deg")
 154       * SGD_DEGREES_TO_RADIANS;
 155     double alt_ft = fgGetDouble("/sim/presets/altitude-ft");
 156     double alt_m = alt_ft * SG_FEET_TO_METER;
 157     set_Longitude( lon );
 158     set_Latitude( lat );
 159     SG_LOG( SG_FLIGHT, SG_INFO, "Checking for lon = "
 160             << lon*SGD_RADIANS_TO_DEGREES << "deg, lat = "
 161             << lat*SGD_RADIANS_TO_DEGREES << "deg, alt = "
 162             << alt_ft << "ft");
 163
 164     double ground_elev_m = get_groundlevel_m(lat, lon, alt_m);
 165     double ground_elev_ft = ground_elev_m * SG_METER_TO_FEET;
 166     _set_Runway_altitude ( ground_elev_ft );
 167
 168     // Set aircraft altitude
 169     if ( fgGetBool("/sim/presets/onground") || alt_ft < ground_elev_ft ) {
 170         fgSetDouble("/position/altitude-ft", ground_elev_ft + 0.1);
 171         set_Altitude( ground_elev_ft + 0.1);
 172     } else {
 173         set_Altitude( alt_ft );
 174     }
 175
 176     // Set ground elevation
 177     SG_LOG( SG_FLIGHT, SG_INFO,
 178             "...initializing ground elevation to " << ground_elev_ft
 179             << "ft..." );
 180
 181     // Set sea-level radius
 182     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing sea-level radius..." );
 183     SG_LOG( SG_FLIGHT, SG_INFO, " lat = "
 184             << fgGetDouble("/sim/presets/latitude-deg")
 185             << " alt = " << get_Altitude() );
 186     double slr = SGGeodesy::SGGeodToSeaLevelRadius(_state.geodetic_position_v);
 187     _set_Sea_level_radius( slr * SG_METER_TO_FEET );
 188
 189     // Set initial Euler angles
 190     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing Euler angles..." );
 191     set_Euler_Angles( fgGetDouble("/sim/presets/roll-deg")
 192                         * SGD_DEGREES_TO_RADIANS,
 193                       fgGetDouble("/sim/presets/pitch-deg")
 194                         * SGD_DEGREES_TO_RADIANS,
 195                       fgGetDouble("/sim/presets/heading-deg")
 196                         * SGD_DEGREES_TO_RADIANS );
 197
 198     // Set initial velocities
 199     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing velocities..." );
 200     if ( !fgHasNode("/sim/presets/speed-set") ) {
 201         set_V_calibrated_kts(0.0);
 202     } else {
 203         const std::string speedset = fgGetString("/sim/presets/speed-set");
 204         if ( speedset == "knots" || speedset == "KNOTS" ) {
 205             set_V_calibrated_kts( fgGetDouble("/sim/presets/airspeed-kt") );
 206         } else if ( speedset == "mach" || speedset == "MACH" ) {
 207             set_Mach_number( fgGetDouble("/sim/presets/mach") );
 208         } else if ( speedset == "UVW" || speedset == "uvw" ) {
 209             set_Velocities_Body(
 210                                      fgGetDouble("/sim/presets/uBody-fps"),
 211                                      fgGetDouble("/sim/presets/vBody-fps"),
 212                                      fgGetDouble("/sim/presets/wBody-fps") );
 213         } else if ( speedset == "NED" || speedset == "ned" ) {
 214             set_Velocities_Local(
 215                                  fgGetDouble("/sim/presets/speed-north-fps"),
 216                                  fgGetDouble("/sim/presets/speed-east-fps"),
 217                                  fgGetDouble("/sim/presets/speed-down-fps") );
 218         } else {
 219             SG_LOG( SG_FLIGHT, SG_ALERT,
 220                     "Unrecognized value for /sim/presets/speed-set: "
 221                     << speedset);
 222             set_V_calibrated_kts( 0.0 );
 223         }
 224     }
 225
 226     if ( fgHasNode("/sim/presets/glideslope-deg") )
 227         set_Gamma_vert_rad( fgGetDouble("/sim/presets/glideslope-deg")
 228                               * SGD_DEGREES_TO_RADIANS );
 229     else if ( fgHasNode("/sim/presets/speed-set") &&
 230               fgHasNode( "/sim/presets/vertical-speed-fps") )
 231     {
 232         set_Climb_Rate( fgGetDouble("/sim/presets/vertical-speed-fps") );
 233     }
 234
 235     SG_LOG( SG_FLIGHT, SG_INFO, "End common FDM init" );
 236 }
 237
 238
 239 /**
 240  * Bind getters and setters to properties.
 241  *
 242  * The bind() method will be invoked after init().  Note that unlike
 243  * the usual implementations of FGSubsystem::bind(), this method does
 244  * not automatically pick up existing values for the properties at
 245  * bind time; instead, all values are set explicitly in the init()
 246  * method.
 247  */
 248 void
 249 FGInterface::bind ()
 250 {
 251   bound = true;
 252
 253   _tiedProperties.setRoot(globals->get_props());
 254   // Aircraft position
 255   _tiedProperties.Tie("/position/latitude-deg", this,
 256                       &FGInterface::get_Latitude_deg,
 257                       &FGInterface::set_Latitude_deg,
 258                       false);
 259   fgSetArchivable("/position/latitude-deg");
 260   _tiedProperties.Tie("/position/longitude-deg", this,
 261                       &FGInterface::get_Longitude_deg,
 262                       &FGInterface::set_Longitude_deg,
 263                       false);
 264   fgSetArchivable("/position/longitude-deg");
 265   _tiedProperties.Tie("/position/altitude-ft", this,
 266                       &FGInterface::get_Altitude,
 267                       &FGInterface::set_Altitude,
 268                       false);
 269   fgSetArchivable("/position/altitude-ft");
 270   _tiedProperties.Tie("/position/altitude-agl-ft", this,
 271                       &FGInterface::get_Altitude_AGL, &FGInterface::set_AltitudeAGL, false);
 272   fgSetArchivable("/position/ground-elev-ft");
 273   _tiedProperties.Tie("/position/ground-elev-ft", this,
 274                       &FGInterface::get_Runway_altitude); // read-only
 275   fgSetArchivable("/position/ground-elev-m");
 276   _tiedProperties.Tie("/position/ground-elev-m", this,
 277                       &FGInterface::get_Runway_altitude_m); // read-only
 278   _tiedProperties.Tie("/environment/ground-elevation-m", this,
 279                       &FGInterface::get_Runway_altitude_m); // read-only
 280   fgSetArchivable("/position/sea-level-radius-ft");
 281   _tiedProperties.Tie("/position/sea-level-radius-ft", this,
 282                       &FGInterface::get_Sea_level_radius,
 283                       &FGInterface::_set_Sea_level_radius, false);
 284
 285   // Orientation
 286   _tiedProperties.Tie("/orientation/roll-deg", this,
 287                       &FGInterface::get_Phi_deg,
 288                       &FGInterface::set_Phi_deg, false);
 289   fgSetArchivable("/orientation/roll-deg");
 290   _tiedProperties.Tie("/orientation/pitch-deg", this,
 291                       &FGInterface::get_Theta_deg,
 292                       &FGInterface::set_Theta_deg, false);
 293   fgSetArchivable("/orientation/pitch-deg");
 294   _tiedProperties.Tie("/orientation/heading-deg", this,
 295                       &FGInterface::get_Psi_deg,
 296                       &FGInterface::set_Psi_deg, false);
 297   fgSetArchivable("/orientation/heading-deg");
 298   _tiedProperties.Tie("/orientation/track-deg", this,
 299                       &FGInterface::get_Track); // read-only
 300   _tiedProperties.Tie("/orientation/path-deg", this,
 301                       &FGInterface::get_Path); // read-only
 302
 303   // Body-axis "euler rates" (rotation speed, but in a funny
 304   // representation).
 305   _tiedProperties.Tie("/orientation/roll-rate-degps", this,
 306                       &FGInterface::get_Phi_dot_degps,
 307                       &FGInterface::set_Phi_dot_degps, false);
 308   _tiedProperties.Tie("/orientation/pitch-rate-degps", this,
 309                       &FGInterface::get_Theta_dot_degps,
 310                       &FGInterface::set_Theta_dot_degps, false);
 311   _tiedProperties.Tie("/orientation/yaw-rate-degps", this,
 312                       &FGInterface::get_Psi_dot_degps,
 313                       &FGInterface::set_Psi_dot_degps, false);
 314
 315   _tiedProperties.Tie("/orientation/p-body", this, &FGInterface::get_P_body); // read-only
 316   _tiedProperties.Tie("/orientation/q-body", this, &FGInterface::get_Q_body); // read-only
 317   _tiedProperties.Tie("/orientation/r-body", this, &FGInterface::get_R_body); // read-only
 318
 319   // Ground speed knots
 320   _tiedProperties.Tie("/velocities/groundspeed-kt", this,
 321                       &FGInterface::get_V_ground_speed_kt,
 322                       &FGInterface::set_V_ground_speed_kt); // read-only
 323
 324   // Calibrated airspeed
 325   _tiedProperties.Tie("/velocities/airspeed-kt", this,
 326                       &FGInterface::get_V_calibrated_kts,
 327                       &FGInterface::set_V_calibrated_kts,
 328                       false);
 329
 330   _tiedProperties.Tie("/velocities/equivalent-kt", this,
 331                       &FGInterface::get_V_equiv_kts); // read-only
 332
 333   // Mach number
 334   _tiedProperties.Tie("/velocities/mach", this,
 335                       &FGInterface::get_Mach_number,
 336                       &FGInterface::set_Mach_number,
 337                       false);
 338
 339   // Local velocities
 340 //   _tiedProperties.Tie("/velocities/speed-north-fps", this,
 341 //                       &FGInterface::get_V_north,
 342 //                       &FGInterface::set_V_north);
 343 //   fgSetArchivable("/velocities/speed-north-fps");
 344 //   _tiedProperties.Tie("/velocities/speed-east-fps", this,
 345 //                       &FGInterface::get_V_east,
 346 //                       &FGInterface::set_V_east);
 347 //   fgSetArchivable("/velocities/speed-east-fps");
 348 //   _tiedProperties.Tie("/velocities/speed-down-fps", this,
 349 //                       &FGInterface::get_V_down,
 350 //                       &FGInterface::set_V_down);
 351 //   fgSetArchivable("/velocities/speed-down-fps");
 352
 353   // FIXME: Temporarily read-only, until the
 354   // incompatibilities between JSBSim and
 355   // LaRCSim are fixed (LaRCSim adds the
 356   // earth's rotation to the east velocity).
 357   _tiedProperties.Tie("/velocities/speed-north-fps", this,
 358                       &FGInterface::get_V_north, &FGInterface::set_V_north, false);
 359   _tiedProperties.Tie("/velocities/speed-east-fps", this,
 360                       &FGInterface::get_V_east, &FGInterface::set_V_east, false);
 361   _tiedProperties.Tie("/velocities/speed-down-fps", this,
 362                       &FGInterface::get_V_down, &FGInterface::set_V_down, false);
 363
 364   _tiedProperties.Tie("/velocities/north-relground-fps", this,
 365                       &FGInterface::get_V_north_rel_ground); // read-only
 366   _tiedProperties.Tie("/velocities/east-relground-fps", this,
 367                       &FGInterface::get_V_east_rel_ground); // read-only
 368   _tiedProperties.Tie("/velocities/down-relground-fps", this,
 369                       &FGInterface::get_V_down_rel_ground); // read-only
 370
 371   // ECEF velocity in body axis
 372   // FIXME: temporarily archivable, until the NED problem is fixed.
 373   _tiedProperties.Tie("/velocities/uBody-fps", this,
 374                       &FGInterface::get_uBody,
 375                       &FGInterface::set_uBody,
 376                       false);
 377   fgSetArchivable("/velocities/uBody-fps");
 378   _tiedProperties.Tie("/velocities/vBody-fps", this,
 379                       &FGInterface::get_vBody,
 380                       &FGInterface::set_vBody,
 381                       false);
 382   fgSetArchivable("/velocities/vBody-fps");
 383   _tiedProperties.Tie("/velocities/wBody-fps", this,
 384                       &FGInterface::get_wBody,
 385                       &FGInterface::set_wBody,
 386                       false);
 387   fgSetArchivable("/velocities/wBody-fps");
 388
 389   // Climb and slip (read-only)
 390   _tiedProperties.Tie("/velocities/vertical-speed-fps", this,
 391                       &FGInterface::get_Climb_Rate,
 392                       &FGInterface::set_Climb_Rate, false );
 393   _tiedProperties.Tie("/velocities/glideslope", this,
 394                       &FGInterface::get_Gamma_vert_rad,
 395                       &FGInterface::set_Gamma_vert_rad, false );
 396   _tiedProperties.Tie("/orientation/side-slip-rad", this,
 397                       &FGInterface::get_Beta, &FGInterface::_set_Beta, false);
 398   _tiedProperties.Tie("/orientation/side-slip-deg", this,
 399                       &FGInterface::get_Beta_deg); // read-only
 400   _tiedProperties.Tie("/orientation/alpha-deg", this,
 401                       &FGInterface::get_Alpha_deg, &FGInterface::set_Alpha_deg, false);
 402   _tiedProperties.Tie("/accelerations/nlf", this,
 403                       &FGInterface::get_Nlf); // read-only
 404
 405   // NED accelerations
 406   _tiedProperties.Tie("/accelerations/ned/north-accel-fps_sec",
 407                       this, &FGInterface::get_V_dot_north); // read-only
 408   _tiedProperties.Tie("/accelerations/ned/east-accel-fps_sec",
 409                       this, &FGInterface::get_V_dot_east); // read-only
 410   _tiedProperties.Tie("/accelerations/ned/down-accel-fps_sec",
 411                       this, &FGInterface::get_V_dot_down); // read-only
 412
 413   // Pilot accelerations
 414   _tiedProperties.Tie("/accelerations/pilot/x-accel-fps_sec",
 415                       this, &FGInterface::get_A_X_pilot, &FGInterface::set_A_X_pilot, false);
 416   _tiedProperties.Tie("/accelerations/pilot/y-accel-fps_sec",
 417                       this, &FGInterface::get_A_Y_pilot, &FGInterface::set_A_Y_pilot, false);
 418   _tiedProperties.Tie("/accelerations/pilot/z-accel-fps_sec",
 419                       this, &FGInterface::get_A_Z_pilot, &FGInterface::set_A_Z_pilot, false);
 420
 421   _tiedProperties.Tie("/accelerations/n-z-cg-fps_sec",
 422                       this, &FGInterface::get_N_Z_cg); // read-only
 423 }
 424
 425
 426 /**
 427  * Unbind any properties bound to this FDM.
 428  *
 429  * This method allows the FDM to release properties so that a new
 430  * FDM can bind them instead.
 431  */
 432 void
 433 FGInterface::unbind ()
 434 {
 435   _tiedProperties.Untie();
 436   bound = false;
 437 }
 438
 439 /**
 440  * Update the state of the FDM (i.e. run the equations of motion).
 441  */
 442 void
 443 FGInterface::update (double dt)
 444 {
 445     SG_LOG(SG_FLIGHT, SG_ALERT, "dummy update() ... SHOULDN'T BE CALLED!");
 446 }
 447
 448 bool FGInterface::readState(SGIOChannel* io)
 449 {
 450     FlightState buf;
 451     int length = sizeof(FlightState);
 452
 453     if ( io->get_type() == sgFileType ) {
 454             if ( io->read( (char *)(& buf), length ) == length ) {
 455             SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
 456             } else {
 457             return false;
 458         }
 459         } else {
 460             while ( io->read( (char *)(& buf), length ) == length ) {
 461             SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
 462             }
 463         }
 464
 465     _state = buf; // copy the read state over
 466     return true;
 467 }
 468
 469 bool FGInterface::writeState(SGIOChannel* io)
 470 {
 471     if (!bound || !inited) {
 472         return false;
 473     }
 474
 475     int length = sizeof(FlightState);
 476     if ( ! io->write( (char *)(& _state), length ) ) {
 477             SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
 478             return false;
 479         }
 480
 481     return true;
 482 }
 483
 484 void FGInterface::_updatePositionM(const SGVec3d& cartPos)
 485 {
 486     TrackComputer tracker( _state.track, _state.path, _state.geodetic_position_v );
 487     _state.cartesian_position_v = cartPos;
 488     _state.geodetic_position_v = SGGeod::fromCart(_state.cartesian_position_v);
 489     _state.geocentric_position_v = SGGeoc::fromCart(_state.cartesian_position_v);
 490     _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(_state.geodetic_position_v)*SG_METER_TO_FEET );
 491     _update_ground_elev_at_pos();
 492 }
 493
 494
 495 void FGInterface::_updatePosition(const SGGeod& geod)
 496 {
 497     TrackComputer tracker( _state.track, _state.path, _state.geodetic_position_v );
 498     _state.geodetic_position_v = geod;
 499     _state.cartesian_position_v = SGVec3d::fromGeod(_state.geodetic_position_v);
 500     _state.geocentric_position_v = SGGeoc::fromCart(_state.cartesian_position_v);
 501
 502     _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(_state.geodetic_position_v)*SG_METER_TO_FEET );
 503     _update_ground_elev_at_pos();
 504 }
 505
 506
 507 void FGInterface::_updatePosition(const SGGeoc& geoc)
 508 {
 509     TrackComputer tracker( _state.track, _state.path, _state.geodetic_position_v );
 510     _state.geocentric_position_v = geoc;
 511     _state.cartesian_position_v = SGVec3d::fromGeoc(_state.geocentric_position_v);
 512     _state.geodetic_position_v = SGGeod::fromCart(_state.cartesian_position_v);
 513
 514     _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(_state.geodetic_position_v)*SG_METER_TO_FEET );
 515     _update_ground_elev_at_pos();
 516 }
 517
 518
 519 void FGInterface::_updateGeodeticPosition( double lat, double lon, double alt )
 520 {
 521     _updatePosition(SGGeod::fromRadFt(lon, lat, alt));
 522 }
 523
 524
 525 void FGInterface::_updateGeocentricPosition( double lat, double lon,
 526                                              double alt )
 527 {
 528     _updatePosition(SGGeoc::fromRadFt(lon, lat, get_Sea_level_radius() + alt));
 529 }
 530
 531 void FGInterface::_update_ground_elev_at_pos( void ) {
 532     double groundlevel_m = get_groundlevel_m(_state.geodetic_position_v);
 533     _set_Runway_altitude( groundlevel_m * SG_METER_TO_FEET );
 534 }
 535
 536 // Positions
 537 void FGInterface::set_Latitude(double lat) {
 538     _state.geodetic_position_v.setLatitudeRad(lat);
 539 }
 540
 541 void FGInterface::set_Longitude(double lon) {
 542     _state.geodetic_position_v.setLongitudeRad(lon);
 543 }
 544
 545 void FGInterface::set_Altitude(double alt) {
 546     _state.geodetic_position_v.setElevationFt(alt);
 547 }
 548
 549 void FGInterface::set_AltitudeAGL(double altagl) {
 550     _state.altitude_agl=altagl;
 551 }
 552
 553 // Velocities
 554 void FGInterface::set_V_calibrated_kts(double vc) {
 555     _state.v_calibrated_kts = vc;
 556 }
 557
 558 void FGInterface::set_Mach_number(double mach) {
 559     _state.mach_number = mach;
 560 }
 561
 562 void FGInterface::set_Velocities_Local( double north,
 563                                         double east,
 564                                         double down ){
 565     _state.v_local_v[0] = north;
 566     _state.v_local_v[1] = east;
 567     _state.v_local_v[2] = down;
 568 }
 569
 570 void FGInterface::set_Velocities_Body( double u,
 571                                             double v,
 572                                             double w){
 573     _state.v_body_v[0] = u;
 574     _state.v_body_v[1] = v;
 575     _state.v_body_v[2] = w;
 576 }
 577
 578 // Euler angles
 579 void FGInterface::set_Euler_Angles( double phi,
 580                                     double theta,
 581                                     double psi ) {
 582     _state.euler_angles_v[0] = phi;
 583     _state.euler_angles_v[1] = theta;
 584     _state.euler_angles_v[2] = psi;
 585 }
 586
 587 // Flight Path
 588 void FGInterface::set_Climb_Rate( double roc) {
 589     _state.climb_rate = roc;
 590 }
 591
 592 void FGInterface::set_Gamma_vert_rad( double gamma) {
 593     _state.gamma_vert_rad = gamma;
 594 }
 595
 596 void FGInterface::set_Static_pressure(double p) { _state.static_pressure = p; }
 597 void FGInterface::set_Static_temperature(double T) { _state.static_temperature = T; }
 598 void FGInterface::set_Density(double rho) { _state.density = rho; }
 599
 600 void FGInterface::set_Velocities_Local_Airmass (double wnorth,
 601                                                 double weast,
 602                                                 double wdown ) {
 603     _state.v_local_airmass_v[0] = wnorth;
 604     _state.v_local_airmass_v[1] = weast;
 605     _state.v_local_airmass_v[2] = wdown;
 606 }
 607
 608
 609 void FGInterface::_busdump(void)
 610 {
 611     SG_LOG(SG_FLIGHT,SG_INFO,"d_cg_rp_body_v: " << _state.d_cg_rp_body_v);
 612     SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_local_v: " << _state.v_dot_local_v);
 613     SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_body_v: " << _state.v_dot_body_v);
 614     SG_LOG(SG_FLIGHT,SG_INFO,"a_cg_body_v: " << _state.a_cg_body_v);
 615     SG_LOG(SG_FLIGHT,SG_INFO,"a_pilot_body_v: " << _state.a_pilot_body_v);
 616     SG_LOG(SG_FLIGHT,SG_INFO,"n_cg_body_v: " << _state.n_cg_body_v);
 617     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_v: " << _state.v_local_v);
 618     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_rel_ground_v: " << _state.v_local_rel_ground_v);
 619     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_airmass_v: " << _state.v_local_airmass_v);
 620     SG_LOG(SG_FLIGHT,SG_INFO,"v_body_v: " << _state.v_body_v);
 621     SG_LOG(SG_FLIGHT,SG_INFO,"omega_body_v: " << _state.omega_body_v);
 622     SG_LOG(SG_FLIGHT,SG_INFO,"euler_rates_v: " << _state.euler_rates_v);
 623     SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_rates_v: " << _state.geocentric_rates_v);
 624     SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_position_v: " << _state.geocentric_position_v);
 625     SG_LOG(SG_FLIGHT,SG_INFO,"geodetic_position_v: " << _state.geodetic_position_v);
 626     SG_LOG(SG_FLIGHT,SG_INFO,"euler_angles_v: " << _state.euler_angles_v);
 627
 628     SG_LOG(SG_FLIGHT,SG_INFO,"nlf: " << _state.nlf );
 629     SG_LOG(SG_FLIGHT,SG_INFO,"v_rel_wind: " << _state.v_rel_wind );
 630     SG_LOG(SG_FLIGHT,SG_INFO,"v_true_kts: " << _state.v_true_kts );
 631     SG_LOG(SG_FLIGHT,SG_INFO,"v_ground_speed: " << _state.v_ground_speed );
 632     SG_LOG(SG_FLIGHT,SG_INFO,"v_equiv_kts: " << _state.v_equiv_kts );
 633     SG_LOG(SG_FLIGHT,SG_INFO,"v_calibrated_kts: " << _state.v_calibrated_kts );
 634     SG_LOG(SG_FLIGHT,SG_INFO,"alpha: " << _state.alpha );
 635     SG_LOG(SG_FLIGHT,SG_INFO,"beta: " << _state.beta );
 636     SG_LOG(SG_FLIGHT,SG_INFO,"gamma_vert_rad: " << _state.gamma_vert_rad );
 637     SG_LOG(SG_FLIGHT,SG_INFO,"density: " << _state.density );
 638     SG_LOG(SG_FLIGHT,SG_INFO,"mach_number: " << _state.mach_number );
 639     SG_LOG(SG_FLIGHT,SG_INFO,"static_pressure: " << _state.static_pressure );
 640     SG_LOG(SG_FLIGHT,SG_INFO,"total_pressure: " << _state.total_pressure );
 641     SG_LOG(SG_FLIGHT,SG_INFO,"dynamic_pressure: " << _state.dynamic_pressure );
 642     SG_LOG(SG_FLIGHT,SG_INFO,"static_temperature: " << _state.static_temperature );
 643     SG_LOG(SG_FLIGHT,SG_INFO,"total_temperature: " << _state.total_temperature );
 644     SG_LOG(SG_FLIGHT,SG_INFO,"sea_level_radius: " << _state.sea_level_radius );
 645     SG_LOG(SG_FLIGHT,SG_INFO,"earth_position_angle: " << _state.earth_position_angle );
 646     SG_LOG(SG_FLIGHT,SG_INFO,"runway_altitude: " << _state.runway_altitude );
 647     SG_LOG(SG_FLIGHT,SG_INFO,"climb_rate: " << _state.climb_rate );
 648     SG_LOG(SG_FLIGHT,SG_INFO,"altitude_agl: " << _state.altitude_agl );
 649 }
 650
 651 bool
 652 FGInterface::prepare_ground_cache_m(double startSimTime, double endSimTime,
 653                                     const double pt[3], double rad)
 654 {
 655   return ground_cache.prepare_ground_cache(startSimTime, endSimTime,
 656                                            SGVec3d(pt), rad);
 657 }
 658
 659 bool
 660 FGInterface::prepare_ground_cache_ft(double startSimTime, double endSimTime,
 661                                      const double pt[3], double rad)
 662 {
 663   // Convert units and do the real work.
 664   SGVec3d pt_ft = SG_FEET_TO_METER*SGVec3d(pt);
 665   return ground_cache.prepare_ground_cache(startSimTime, endSimTime,
 666                                            pt_ft, rad*SG_FEET_TO_METER);
 667 }
 668
 669 bool
 670 FGInterface::is_valid_m(double *ref_time, double pt[3], double *rad)
 671 {
 672   SGVec3d _pt;
 673   bool valid = ground_cache.is_valid(*ref_time, _pt, *rad);
 674   assign(pt, _pt);
 675   return valid;
 676 }
 677
 678 bool FGInterface::is_valid_ft(double *ref_time, double pt[3], double *rad)
 679 {
 680   // Convert units and do the real work.
 681   SGVec3d _pt;
 682   bool found_ground = ground_cache.is_valid(*ref_time, _pt, *rad);
 683   assign(pt, SG_METER_TO_FEET*_pt);
 684   *rad *= SG_METER_TO_FEET;
 685   return found_ground;
 686 }
 687
 688 double
 689 FGInterface::get_cat_m(double t, const double pt[3],
 690                        double end[2][3], double vel[2][3])
 691 {
 692   SGVec3d _end[2], _vel[2];
 693   double dist = ground_cache.get_cat(t, SGVec3d(pt), _end, _vel);
 694   for (int k=0; k<2; ++k) {
 695     assign( end[k], _end[k] );
 696     assign( vel[k], _vel[k] );
 697   }
 698   return dist;
 699 }
 700
 701 double
 702 FGInterface::get_cat_ft(double t, const double pt[3],
 703                         double end[2][3], double vel[2][3])
 704 {
 705   // Convert units and do the real work.
 706   SGVec3d pt_m = SG_FEET_TO_METER*SGVec3d(pt);
 707   SGVec3d _end[2], _vel[2];
 708   double dist = ground_cache.get_cat(t, pt_m, _end, _vel);
 709   for (int k=0; k<2; ++k) {
 710     assign( end[k], SG_METER_TO_FEET*_end[k] );
 711     assign( vel[k], SG_METER_TO_FEET*_vel[k] );
 712   }
 713   return dist*SG_METER_TO_FEET;
 714 }
 715
 716 bool
 717 FGInterface::get_body_m(double t, simgear::BVHNode::Id id,
 718                         double bodyToWorld[16], double linearVel[3],
 719                         double angularVel[3])
 720 {
 721   SGMatrixd _bodyToWorld;
 722   SGVec3d _linearVel, _angularVel;
 723   if (!ground_cache.get_body(t, _bodyToWorld, _linearVel, _angularVel, id))
 724     return false;
 725
 726   assign(linearVel, _linearVel);
 727   assign(angularVel, _angularVel);
 728   for (unsigned i = 0; i < 16; ++i)
 729       bodyToWorld[i] = _bodyToWorld.data()[i];
 730
 731   return true;
 732 }
 733
 734 bool
 735 FGInterface::get_agl_m(double t, const double pt[3], double max_altoff,
 736                        double contact[3], double normal[3],
 737                        double linearVel[3], double angularVel[3],
 738                        simgear::BVHMaterial const*& material, simgear::BVHNode::Id& id)
 739 {
 740   SGVec3d pt_m = SGVec3d(pt) - max_altoff*ground_cache.get_down();
 741   SGVec3d _contact, _normal, _linearVel, _angularVel;
 742   material = 0;
 743   bool ret = ground_cache.get_agl(t, pt_m, _contact, _normal, _linearVel,
 744                                   _angularVel, id, material);
 745   // correct the linear velocity, since the line intersector delivers
 746   // values for the start point and the get_agl function should
 747   // traditionally deliver for the contact point
 748   _linearVel += cross(_angularVel, _contact - pt_m);
 749
 750   assign(contact, _contact);
 751   assign(normal, _normal);
 752   assign(linearVel, _linearVel);
 753   assign(angularVel, _angularVel);
 754   return ret;
 755 }
 756
 757 bool
 758 FGInterface::get_agl_ft(double t, const double pt[3], double max_altoff,
 759                         double contact[3], double normal[3],
 760                         double linearVel[3], double angularVel[3],
 761                         simgear::BVHMaterial const*& material, simgear::BVHNode::Id& id)
 762 {
 763   // Convert units and do the real work.
 764   SGVec3d pt_m = SGVec3d(pt) - max_altoff*ground_cache.get_down();
 765   pt_m *= SG_FEET_TO_METER;
 766   SGVec3d _contact, _normal, _linearVel, _angularVel;
 767   material = 0;
 768   bool ret = ground_cache.get_agl(t, pt_m, _contact, _normal, _linearVel,
 769                                   _angularVel, id, material);
 770   // correct the linear velocity, since the line intersector delivers
 771   // values for the start point and the get_agl function should
 772   // traditionally deliver for the contact point
 773   _linearVel += cross(_angularVel, _contact - pt_m);
 774
 775   // Convert units back ...
 776   assign( contact, SG_METER_TO_FEET*_contact );
 777   assign( normal, _normal );
 778   assign( linearVel, SG_METER_TO_FEET*_linearVel );
 779   assign( angularVel, _angularVel );
 780   return ret;
 781 }
 782
 783 bool
 784 FGInterface::get_nearest_m(double t, const double pt[3], double maxDist,
 785                            double contact[3], double normal[3],
 786                            double linearVel[3], double angularVel[3],
 787                            simgear::BVHMaterial const*& material,
 788                            simgear::BVHNode::Id& id)
 789 {
 790   SGVec3d _contact, _linearVel, _angularVel;
 791   material = 0;
 792   if (!ground_cache.get_nearest(t, SGVec3d(pt), maxDist, _contact, _linearVel,
 793                                 _angularVel, id, material))
 794       return false;
 795
 796   assign(contact, _contact);
 797   assign(linearVel, _linearVel);
 798   assign(angularVel, _angularVel);
 799   return true;
 800 }
 801
 802 bool
 803 FGInterface::get_nearest_ft(double t, const double pt[3], double maxDist,
 804                             double contact[3], double normal[3],
 805                             double linearVel[3], double angularVel[3],
 806                             simgear::BVHMaterial const*& material,
 807                             simgear::BVHNode::Id& id)
 808 {
 809   SGVec3d _contact, _linearVel, _angularVel;
 810   material = 0;
 811   if (!ground_cache.get_nearest(t, SG_FEET_TO_METER*SGVec3d(pt),
 812                                 SG_FEET_TO_METER*maxDist, _contact, _linearVel,
 813                                 _angularVel, id, material))
 814       return false;
 815
 816   assign(contact, SG_METER_TO_FEET*_contact);
 817   assign(linearVel, SG_METER_TO_FEET*_linearVel);
 818   assign(angularVel, _angularVel);
 819   return true;
 820 }
 821
 822 double
 823 FGInterface::get_groundlevel_m(double lat, double lon, double alt)
 824 {
 825   return get_groundlevel_m(SGGeod::fromRadM(lon, lat, alt));
 826 }
 827
 828 double
 829 FGInterface::get_groundlevel_m(const SGGeod& geod)
 830 {
 831   // Compute the cartesian position of the given lat/lon/alt.
 832   SGVec3d pos = SGVec3d::fromGeod(geod);
 833
 834   // FIXME: how to handle t - ref_time differences ???
 835   SGVec3d cpos;
 836   double ref_time = 0, radius;
 837   // Prepare the ground cache for that position.
 838   if (!is_valid_m(&ref_time, cpos.data(), &radius)) {
 839     double startTime = ref_time;
 840     double endTime = startTime + 1;
 841     bool ok = prepare_ground_cache_m(startTime, endTime, pos.data(), 10);
 842     /// This is most likely the case when the given altitude is
 843     /// too low, try with a new altitude of 10000m, that should be
 844     /// sufficient to find a ground level below everywhere on our planet
 845     if (!ok) {
 846       pos = SGVec3d::fromGeod(SGGeod::fromGeodM(geod, 10000));
 847       /// If there is still no ground, return sea level radius
 848       if (!prepare_ground_cache_m(startTime, endTime, pos.data(), 10))
 849         return 0;
 850     }
 851   } else if (radius*radius <= distSqr(pos, cpos)) {
 852     double startTime = ref_time;
 853     double endTime = startTime + 1;
 854
 855     /// We reuse the old radius value, but only if it is at least 10 Meters ..
 856     if (!(10 < radius)) // Well this strange compare is nan safe
 857       radius = 10;
 858
 859     bool ok = prepare_ground_cache_m(startTime, endTime, pos.data(), radius);
 860     /// This is most likely the case when the given altitude is
 861     /// too low, try with a new altitude of 10000m, that should be
 862     /// sufficient to find a ground level below everywhere on our planet
 863     if (!ok) {
 864       pos = SGVec3d::fromGeod(SGGeod::fromGeodM(geod, 10000));
 865       /// If there is still no ground, return sea level radius
 866       if (!prepare_ground_cache_m(startTime, endTime, pos.data(), radius))
 867         return 0;
 868     }
 869   }
 870
 871   double contact[3], normal[3], vel[3], angvel[3];
 872   const simgear::BVHMaterial* material;
 873   simgear::BVHNode::Id id;
 874   // Ignore the return value here, since it just tells us if
 875   // the returns stem from the groundcache or from the coarse
 876   // computations below the groundcache. The contact point is still something
 877   // valid, the normals and the other returns just contain some defaults.
 878   get_agl_m(ref_time, pos.data(), 2.0, contact, normal, vel, angvel,
 879             material, id);
 880   return SGGeod::fromCart(SGVec3d(contact)).getElevationM();
 881 }
 882
 883 bool
 884 FGInterface::caught_wire_m(double t, const double pt[4][3])
 885 {
 886   SGVec3d pt_m[4];
 887   for (int i=0; i<4; ++i)
 888     pt_m[i] = SGVec3d(pt[i]);
 889
 890   return ground_cache.caught_wire(t, pt_m);
 891 }
 892
 893 bool
 894 FGInterface::caught_wire_ft(double t, const double pt[4][3])
 895 {
 896   // Convert units and do the real work.
 897   SGVec3d pt_m[4];
 898   for (int i=0; i<4; ++i)
 899     pt_m[i] = SG_FEET_TO_METER*SGVec3d(pt[i]);
 900
 901   return ground_cache.caught_wire(t, pt_m);
 902 }
 903
 904 bool
 905 FGInterface::get_wire_ends_m(double t, double end[2][3], double vel[2][3])
 906 {
 907   SGVec3d _end[2], _vel[2];
 908   bool ret = ground_cache.get_wire_ends(t, _end, _vel);
 909   for (int k=0; k<2; ++k) {
 910     assign( end[k], _end[k] );
 911     assign( vel[k], _vel[k] );
 912   }
 913   return ret;
 914 }
 915
 916 bool
 917 FGInterface::get_wire_ends_ft(double t, double end[2][3], double vel[2][3])
 918 {
 919   // Convert units and do the real work.
 920   SGVec3d _end[2], _vel[2];
 921   bool ret = ground_cache.get_wire_ends(t, _end, _vel);
 922   for (int k=0; k<2; ++k) {
 923     assign( end[k], SG_METER_TO_FEET*_end[k] );
 924     assign( vel[k], SG_METER_TO_FEET*_vel[k] );
 925   }
 926   return ret;
 927 }
 928
 929 void
 930 FGInterface::release_wire(void)
 931 {
 932   ground_cache.release_wire();
 933 }
 934