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