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 // base_fdm_state is the internal state that is updated in integer
  48 // multiples of "dt".  This leads to "jitter" with respect to the real
  49 // world time, so we introduce cur_fdm_state which is extrapolated by
  50 // the difference between sim time and real world time
  51
  52 FGInterface *cur_fdm_state = 0;
  53 FGInterface base_fdm_state;
  54
  55 // Constructor
  56 FGInterface::FGInterface()
  57   : remainder(0)
  58 {
  59     _setup();
  60 }
  61
  62 FGInterface::FGInterface( double dt )
  63   : remainder(0)
  64 {
  65     _setup();
  66 }
  67
  68 // Destructor
  69 FGInterface::~FGInterface() {
  70     // unbind();                   // FIXME: should be called explicitly
  71 }
  72
  73
  74 int
  75 FGInterface::_calc_multiloop (double dt)
  76 {
  77   int hz = fgGetInt("/sim/model-hz");
  78   int speedup = fgGetInt("/sim/speed-up");
  79
  80   dt += remainder;
  81   remainder = 0;
  82   double ml = dt * hz;
  83   // Avoid roundoff problems by adding the roundoff itself.
  84   // ... ok, two times the roundoff to have enough room.
  85   int multiloop = int(floor(ml * (1.0 + 2.0*DBL_EPSILON)));
  86   remainder = (ml - multiloop) / hz;
  87
  88   // If we artificially inflate ml above by a tiny amount to get the
  89   // closest integer, then subtract the integer from the original
  90   // slightly smaller value, we can get a negative remainder.
  91   // Logically this should never happen, and we definitely don't want
  92   // to carry a negative remainder over to the next iteration, so
  93   // never let the remainder go below zero.
  94   //
  95   // Note: this fixes a problem where we run 1, 3, 1, 3, 1, 3... loops
  96   // of the FDM when in fact we want to run 2, 2, 2, 2, 2...
  97   if ( remainder < 0 ) { remainder = 0; }
  98
  99   return (multiloop * speedup);
 100 }
 101
 102
 103 /**
 104  * Set default values for the state of the FDM.
 105  *
 106  * This method is invoked by the constructors.
 107  */
 108 void
 109 FGInterface::_setup ()
 110 {
 111     inited = false;
 112     bound = false;
 113
 114     d_cg_rp_body_v = SGVec3d::zeros();
 115     v_dot_local_v = SGVec3d::zeros();
 116     v_dot_body_v = SGVec3d::zeros();
 117     a_cg_body_v = SGVec3d::zeros();
 118     a_pilot_body_v = SGVec3d::zeros();
 119     n_cg_body_v = SGVec3d::zeros();
 120     v_local_v = SGVec3d::zeros();
 121     v_local_rel_ground_v = SGVec3d::zeros();
 122     v_local_airmass_v = SGVec3d::zeros();
 123     v_wind_body_v = SGVec3d::zeros();
 124     omega_body_v = SGVec3d::zeros();
 125     euler_rates_v = SGVec3d::zeros();
 126     geocentric_rates_v = SGVec3d::zeros();
 127     geodetic_position_v = SGGeod::fromRadM(0, 0, 0);
 128     cartesian_position_v = SGVec3d::fromGeod(geodetic_position_v);
 129     geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
 130     euler_angles_v = SGVec3d::zeros();
 131
 132     nlf=0;
 133     v_rel_wind=v_true_kts=0;
 134     v_ground_speed=v_equiv_kts=0;
 135     v_calibrated_kts=0;
 136     alpha=beta=0;
 137     gamma_vert_rad=0;
 138     density=mach_number=0;
 139     static_pressure=total_pressure=0;
 140     dynamic_pressure=0;
 141     static_temperature=total_temperature=0;
 142     sea_level_radius=earth_position_angle=0;
 143     runway_altitude=0;
 144     climb_rate=0;
 145     altitude_agl=0;
 146 }
 147
 148 void
 149 FGInterface::init () {}
 150
 151 /**
 152  * Initialize the state of the FDM.
 153  *
 154  * Subclasses of FGInterface may do their own, additional initialization,
 155  * but there is some that is common to all.  Normally, they should call
 156  * this before they begin their own init to make sure the basic structures
 157  * are set up properly.
 158  */
 159 void
 160 FGInterface::common_init ()
 161 {
 162     SG_LOG( SG_FLIGHT, SG_INFO, "Start common FDM init" );
 163
 164     set_inited( true );
 165
 166 //     stamp();
 167 //     set_remainder( 0 );
 168
 169     // Set initial position
 170     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing position..." );
 171     double lon = fgGetDouble("/sim/presets/longitude-deg")
 172       * SGD_DEGREES_TO_RADIANS;
 173     double lat = fgGetDouble("/sim/presets/latitude-deg")
 174       * SGD_DEGREES_TO_RADIANS;
 175     double alt_ft = fgGetDouble("/sim/presets/altitude-ft");
 176     double alt_m = alt_ft * SG_FEET_TO_METER;
 177     set_Longitude( lon );
 178     set_Latitude( lat );
 179     SG_LOG( SG_FLIGHT, SG_INFO, "Checking for lon = "
 180             << lon*SGD_RADIANS_TO_DEGREES << "deg, lat = "
 181             << lat*SGD_RADIANS_TO_DEGREES << "deg, alt = "
 182             << alt_ft << "ft");
 183
 184     double ground_elev_m = get_groundlevel_m(lat, lon, alt_m);
 185     double ground_elev_ft = ground_elev_m * SG_METER_TO_FEET;
 186     _set_Runway_altitude ( ground_elev_ft );
 187     if ( fgGetBool("/sim/presets/onground") || alt_ft < ground_elev_ft ) {
 188         fgSetDouble("/position/altitude-ft", ground_elev_ft + 0.1);
 189         set_Altitude( ground_elev_ft + 0.1);
 190     } else {
 191         set_Altitude( alt_ft );
 192     }
 193
 194     // Set ground elevation
 195     SG_LOG( SG_FLIGHT, SG_INFO,
 196             "...initializing ground elevation to " << ground_elev_ft
 197             << "ft..." );
 198
 199     // Set sea-level radius
 200     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing sea-level radius..." );
 201     SG_LOG( SG_FLIGHT, SG_INFO, " lat = "
 202             << fgGetDouble("/sim/presets/latitude-deg")
 203             << " alt = " << get_Altitude() );
 204     double slr = SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v);
 205     _set_Sea_level_radius( slr * SG_METER_TO_FEET );
 206
 207     // Set initial velocities
 208     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing velocities..." );
 209     if ( !fgHasNode("/sim/presets/speed-set") ) {
 210         set_V_calibrated_kts(0.0);
 211     } else {
 212         const string speedset = fgGetString("/sim/presets/speed-set");
 213         if ( speedset == "knots" || speedset == "KNOTS" ) {
 214             set_V_calibrated_kts( fgGetDouble("/sim/presets/airspeed-kt") );
 215         } else if ( speedset == "mach" || speedset == "MACH" ) {
 216             set_Mach_number( fgGetDouble("/sim/presets/mach") );
 217         } else if ( speedset == "UVW" || speedset == "uvw" ) {
 218             set_Velocities_Wind_Body(
 219                                      fgGetDouble("/sim/presets/uBody-fps"),
 220                                      fgGetDouble("/sim/presets/vBody-fps"),
 221                                      fgGetDouble("/sim/presets/wBody-fps") );
 222         } else if ( speedset == "NED" || speedset == "ned" ) {
 223             set_Velocities_Local(
 224                                  fgGetDouble("/sim/presets/speed-north-fps"),
 225                                  fgGetDouble("/sim/presets/speed-east-fps"),
 226                                  fgGetDouble("/sim/presets/speed-down-fps") );
 227         } else {
 228             SG_LOG( SG_FLIGHT, SG_ALERT,
 229                     "Unrecognized value for /sim/presets/speed-set: "
 230                     << speedset);
 231             set_V_calibrated_kts( 0.0 );
 232         }
 233     }
 234
 235     // Set initial Euler angles
 236     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing Euler angles..." );
 237     set_Euler_Angles( fgGetDouble("/sim/presets/roll-deg")
 238                         * SGD_DEGREES_TO_RADIANS,
 239                       fgGetDouble("/sim/presets/pitch-deg")
 240                         * SGD_DEGREES_TO_RADIANS,
 241                       fgGetDouble("/sim/presets/heading-deg")
 242                         * SGD_DEGREES_TO_RADIANS );
 243
 244     SG_LOG( SG_FLIGHT, SG_INFO, "End common FDM init" );
 245 }
 246
 247
 248 /**
 249  * Bind getters and setters to properties.
 250  *
 251  * The bind() method will be invoked after init().  Note that unlike
 252  * the usual implementations of FGSubsystem::bind(), this method does
 253  * not automatically pick up existing values for the properties at
 254  * bind time; instead, all values are set explicitly in the init()
 255  * method.
 256  */
 257 void
 258 FGInterface::bind ()
 259 {
 260   bound = true;
 261
 262                                 // Time management (read-only)
 263 //   fgTie("/fdm/time/delta_t", this,
 264 //         &FGInterface::get_delta_t); // read-only
 265 //   fgTie("/fdm/time/elapsed", this,
 266 //         &FGInterface::get_elapsed); // read-only
 267 //   fgTie("/fdm/time/remainder", this,
 268 //         &FGInterface::get_remainder); // read-only
 269 //   fgTie("/fdm/time/multi_loop", this,
 270 //         &FGInterface::get_multi_loop); // read-only
 271
 272                         // Aircraft position
 273   fgTie("/position/latitude-deg", this,
 274         &FGInterface::get_Latitude_deg,
 275         &FGInterface::set_Latitude_deg,
 276         false);
 277   fgSetArchivable("/position/latitude-deg");
 278   fgTie("/position/longitude-deg", this,
 279         &FGInterface::get_Longitude_deg,
 280         &FGInterface::set_Longitude_deg,
 281         false);
 282   fgSetArchivable("/position/longitude-deg");
 283   fgTie("/position/altitude-ft", this,
 284         &FGInterface::get_Altitude,
 285         &FGInterface::set_Altitude,
 286         false);
 287   fgSetArchivable("/position/altitude-ft");
 288   fgTie("/position/altitude-agl-ft", this,
 289         &FGInterface::get_Altitude_AGL); // read-only
 290   fgSetArchivable("/position/ground-elev-ft");
 291   fgTie("/position/ground-elev-ft", this,
 292         &FGInterface::get_Runway_altitude); // read-only
 293   fgSetArchivable("/position/ground-elev-m");
 294   fgTie("/position/ground-elev-m", this,
 295         &FGInterface::get_Runway_altitude_m); // read-only
 296   fgTie("/environment/ground-elevation-m", this,
 297         &FGInterface::get_Runway_altitude_m); // read-only
 298   fgSetArchivable("/position/sea-level-radius-ft");
 299   fgTie("/position/sea-level-radius-ft", this,
 300         &FGInterface::get_Sea_level_radius); // read-only
 301
 302                                 // Orientation
 303   fgTie("/orientation/roll-deg", this,
 304         &FGInterface::get_Phi_deg,
 305         &FGInterface::set_Phi_deg);
 306   fgSetArchivable("/orientation/roll-deg");
 307   fgTie("/orientation/pitch-deg", this,
 308         &FGInterface::get_Theta_deg,
 309         &FGInterface::set_Theta_deg);
 310   fgSetArchivable("/orientation/pitch-deg");
 311   fgTie("/orientation/heading-deg", this,
 312         &FGInterface::get_Psi_deg,
 313         &FGInterface::set_Psi_deg);
 314   fgSetArchivable("/orientation/heading-deg");
 315
 316   // Body-axis "euler rates" (rotation speed, but in a funny
 317   // representation).
 318   fgTie("/orientation/roll-rate-degps", this,
 319         &FGInterface::get_Phi_dot_degps);
 320   fgTie("/orientation/pitch-rate-degps", this,
 321         &FGInterface::get_Theta_dot_degps);
 322   fgTie("/orientation/yaw-rate-degps", this,
 323         &FGInterface::get_Psi_dot_degps);
 324
 325                                 // Ground speed knots
 326   fgTie("/velocities/groundspeed-kt", this,
 327         &FGInterface::get_V_ground_speed_kt);
 328
 329                                 // Calibrated airspeed
 330   fgTie("/velocities/airspeed-kt", this,
 331         &FGInterface::get_V_calibrated_kts,
 332         &FGInterface::set_V_calibrated_kts,
 333         false);
 334
 335                                 // Mach number
 336   fgTie("/velocities/mach", this,
 337         &FGInterface::get_Mach_number,
 338         &FGInterface::set_Mach_number,
 339         false);
 340
 341                                 // Local velocities
 342 //   fgTie("/velocities/speed-north-fps", this,
 343 //      &FGInterface::get_V_north,
 344 //      &FGInterface::set_V_north);
 345 //   fgSetArchivable("/velocities/speed-north-fps");
 346 //   fgTie("/velocities/speed-east-fps", this,
 347 //      &FGInterface::get_V_east,
 348 //      &FGInterface::set_V_east);
 349 //   fgSetArchivable("/velocities/speed-east-fps");
 350 //   fgTie("/velocities/speed-down-fps", this,
 351 //      &FGInterface::get_V_down,
 352 //      &FGInterface::set_V_down);
 353 //   fgSetArchivable("/velocities/speed-down-fps");
 354                                 // FIXME: Temporarily read-only, until the
 355                                 // incompatibilities between JSBSim and
 356                                 // LaRCSim are fixed (LaRCSim adds the
 357                                 // earth's rotation to the east velocity).
 358   fgTie("/velocities/speed-north-fps", this,
 359         &FGInterface::get_V_north);
 360   fgTie("/velocities/speed-east-fps", this,
 361         &FGInterface::get_V_east);
 362   fgTie("/velocities/speed-down-fps", this,
 363         &FGInterface::get_V_down);
 364
 365                                 // Relative wind
 366                                 // FIXME: temporarily archivable, until
 367                                 // the NED problem is fixed.
 368   fgTie("/velocities/uBody-fps", this,
 369         &FGInterface::get_uBody,
 370         &FGInterface::set_uBody,
 371         false);
 372   fgSetArchivable("/velocities/uBody-fps");
 373   fgTie("/velocities/vBody-fps", this,
 374         &FGInterface::get_vBody,
 375         &FGInterface::set_vBody,
 376         false);
 377   fgSetArchivable("/velocities/vBody-fps");
 378   fgTie("/velocities/wBody-fps", this,
 379         &FGInterface::get_wBody,
 380         &FGInterface::set_wBody,
 381         false);
 382   fgSetArchivable("/velocities/wBody-fps");
 383
 384                                 // Climb and slip (read-only)
 385   fgTie("/velocities/vertical-speed-fps", this,
 386         &FGInterface::get_Climb_Rate,
 387   &FGInterface::set_Climb_Rate );
 388   fgTie("/velocities/glideslope", this,
 389   &FGInterface::get_Gamma_vert_rad,
 390   &FGInterface::set_Gamma_vert_rad );
 391   fgTie("/orientation/side-slip-rad", this,
 392         &FGInterface::get_Beta); // read-only
 393   fgTie("/orientation/side-slip-deg", this,
 394   &FGInterface::get_Beta_deg); // read-only
 395   fgTie("/orientation/alpha-deg", this,
 396   &FGInterface::get_Alpha_deg); // read-only
 397   fgTie("/accelerations/nlf", this,
 398   &FGInterface::get_Nlf); // read-only
 399
 400                                 // NED accelerations
 401   fgTie("/accelerations/ned/north-accel-fps_sec",
 402         this, &FGInterface::get_V_dot_north);
 403   fgTie("/accelerations/ned/east-accel-fps_sec",
 404         this, &FGInterface::get_V_dot_east);
 405   fgTie("/accelerations/ned/down-accel-fps_sec",
 406         this, &FGInterface::get_V_dot_down);
 407
 408                                 // Pilot accelerations
 409   fgTie("/accelerations/pilot/x-accel-fps_sec",
 410         this, &FGInterface::get_A_X_pilot);
 411   fgTie("/accelerations/pilot/y-accel-fps_sec",
 412         this, &FGInterface::get_A_Y_pilot);
 413   fgTie("/accelerations/pilot/z-accel-fps_sec",
 414         this, &FGInterface::get_A_Z_pilot);
 415
 416 }
 417
 418
 419 /**
 420  * Unbind any properties bound to this FDM.
 421  *
 422  * This method allows the FDM to release properties so that a new
 423  * FDM can bind them instead.
 424  */
 425 void
 426 FGInterface::unbind ()
 427 {
 428   bound = false;
 429
 430   // fgUntie("/fdm/time/delta_t");
 431   // fgUntie("/fdm/time/elapsed");
 432   // fgUntie("/fdm/time/remainder");
 433   // fgUntie("/fdm/time/multi_loop");
 434   fgUntie("/position/latitude-deg");
 435   fgUntie("/position/longitude-deg");
 436   fgUntie("/position/altitude-ft");
 437   fgUntie("/position/altitude-agl-ft");
 438   fgUntie("/position/ground-elev-ft");
 439   fgUntie("/position/ground-elev-m");
 440   fgUntie("/environment/ground-elevation-m");
 441   fgUntie("/position/sea-level-radius-ft");
 442   fgUntie("/orientation/roll-deg");
 443   fgUntie("/orientation/pitch-deg");
 444   fgUntie("/orientation/heading-deg");
 445   fgUntie("/orientation/roll-rate-degps");
 446   fgUntie("/orientation/pitch-rate-degps");
 447   fgUntie("/orientation/yaw-rate-degps");
 448   fgUntie("/orientation/side-slip-rad");
 449   fgUntie("/orientation/side-slip-deg");
 450   fgUntie("/orientation/alpha-deg");
 451   fgUntie("/velocities/airspeed-kt");
 452   fgUntie("/velocities/groundspeed-kt");
 453   fgUntie("/velocities/mach");
 454   fgUntie("/velocities/speed-north-fps");
 455   fgUntie("/velocities/speed-east-fps");
 456   fgUntie("/velocities/speed-down-fps");
 457   fgUntie("/velocities/uBody-fps");
 458   fgUntie("/velocities/vBody-fps");
 459   fgUntie("/velocities/wBody-fps");
 460   fgUntie("/velocities/vertical-speed-fps");
 461   fgUntie("/velocities/glideslope");
 462   fgUntie("/accelerations/nlf");
 463   fgUntie("/accelerations/pilot/x-accel-fps_sec");
 464   fgUntie("/accelerations/pilot/y-accel-fps_sec");
 465   fgUntie("/accelerations/pilot/z-accel-fps_sec");
 466   fgUntie("/accelerations/ned/north-accel-fps_sec");
 467   fgUntie("/accelerations/ned/east-accel-fps_sec");
 468   fgUntie("/accelerations/ned/down-accel-fps_sec");
 469 }
 470
 471 /**
 472  * Update the state of the FDM (i.e. run the equations of motion).
 473  */
 474 void
 475 FGInterface::update (double dt)
 476 {
 477     SG_LOG(SG_FLIGHT, SG_ALERT, "dummy update() ... SHOULDN'T BE CALLED!");
 478 }
 479
 480
 481 void FGInterface::_updatePositionM(const SGVec3d& cartPos)
 482 {
 483     cartesian_position_v = cartPos;
 484     geodetic_position_v = SGGeod::fromCart(cartesian_position_v);
 485     geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
 486     _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
 487     _update_ground_elev_at_pos();
 488 }
 489
 490
 491 void FGInterface::_updatePosition(const SGGeod& geod)
 492 {
 493     geodetic_position_v = geod;
 494     cartesian_position_v = SGVec3d::fromGeod(geodetic_position_v);
 495     geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
 496
 497     _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
 498     _update_ground_elev_at_pos();
 499 }
 500
 501
 502 void FGInterface::_updatePosition(const SGGeoc& geoc)
 503 {
 504     geocentric_position_v = geoc;
 505     cartesian_position_v = SGVec3d::fromGeoc(geocentric_position_v);
 506     geodetic_position_v = SGGeod::fromCart(cartesian_position_v);
 507
 508     _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
 509     _update_ground_elev_at_pos();
 510 }
 511
 512
 513 void FGInterface::_updateGeodeticPosition( double lat, double lon, double alt )
 514 {
 515     _updatePosition(SGGeod::fromRadFt(lon, lat, alt));
 516 }
 517
 518
 519 void FGInterface::_updateGeocentricPosition( double lat, double lon,
 520                                              double alt )
 521 {
 522     _updatePosition(SGGeoc::fromRadFt(lon, lat, get_Sea_level_radius() + alt));
 523 }
 524
 525 void FGInterface::_update_ground_elev_at_pos( void ) {
 526     double groundlevel_m = get_groundlevel_m(geodetic_position_v);
 527     _set_Runway_altitude( groundlevel_m * SG_METER_TO_FEET );
 528 }
 529
 530 // Positions
 531 void FGInterface::set_Latitude(double lat) {
 532     geodetic_position_v.setLatitudeRad(lat);
 533 }
 534
 535 void FGInterface::set_Longitude(double lon) {
 536     geodetic_position_v.setLongitudeRad(lon);
 537 }
 538
 539 void FGInterface::set_Altitude(double alt) {
 540     geodetic_position_v.setElevationFt(alt);
 541 }
 542
 543 void FGInterface::set_AltitudeAGL(double altagl) {
 544     altitude_agl=altagl;
 545 }
 546
 547 // Velocities
 548 void FGInterface::set_V_calibrated_kts(double vc) {
 549     v_calibrated_kts = vc;
 550 }
 551
 552 void FGInterface::set_Mach_number(double mach) {
 553     mach_number = mach;
 554 }
 555
 556 void FGInterface::set_Velocities_Local( double north,
 557                                         double east,
 558                                         double down ){
 559     v_local_v[0] = north;
 560     v_local_v[1] = east;
 561     v_local_v[2] = down;
 562 }
 563
 564 void FGInterface::set_Velocities_Wind_Body( double u,
 565                                             double v,
 566                                             double w){
 567     v_wind_body_v[0] = u;
 568     v_wind_body_v[1] = v;
 569     v_wind_body_v[2] = w;
 570 }
 571
 572 // Euler angles
 573 void FGInterface::set_Euler_Angles( double phi,
 574                                     double theta,
 575                                     double psi ) {
 576     euler_angles_v[0] = phi;
 577     euler_angles_v[1] = theta;
 578     euler_angles_v[2] = psi;
 579 }
 580
 581 // Flight Path
 582 void FGInterface::set_Climb_Rate( double roc) {
 583     climb_rate = roc;
 584 }
 585
 586 void FGInterface::set_Gamma_vert_rad( double gamma) {
 587     gamma_vert_rad = gamma;
 588 }
 589
 590 void FGInterface::set_Static_pressure(double p) { static_pressure = p; }
 591 void FGInterface::set_Static_temperature(double T) { static_temperature = T; }
 592 void FGInterface::set_Density(double rho) { density = rho; }
 593
 594 void FGInterface::set_Velocities_Local_Airmass (double wnorth,
 595                                                 double weast,
 596                                                 double wdown ) {
 597     v_local_airmass_v[0] = wnorth;
 598     v_local_airmass_v[1] = weast;
 599     v_local_airmass_v[2] = wdown;
 600 }
 601
 602
 603 void FGInterface::_busdump(void) {
 604
 605     SG_LOG(SG_FLIGHT,SG_INFO,"d_cg_rp_body_v: " << d_cg_rp_body_v);
 606     SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_local_v: " << v_dot_local_v);
 607     SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_body_v: " << v_dot_body_v);
 608     SG_LOG(SG_FLIGHT,SG_INFO,"a_cg_body_v: " << a_cg_body_v);
 609     SG_LOG(SG_FLIGHT,SG_INFO,"a_pilot_body_v: " << a_pilot_body_v);
 610     SG_LOG(SG_FLIGHT,SG_INFO,"n_cg_body_v: " << n_cg_body_v);
 611     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_v: " << v_local_v);
 612     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_rel_ground_v: " << v_local_rel_ground_v);
 613     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_airmass_v: " << v_local_airmass_v);
 614     SG_LOG(SG_FLIGHT,SG_INFO,"v_wind_body_v: " << v_wind_body_v);
 615     SG_LOG(SG_FLIGHT,SG_INFO,"omega_body_v: " << omega_body_v);
 616     SG_LOG(SG_FLIGHT,SG_INFO,"euler_rates_v: " << euler_rates_v);
 617     SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_rates_v: " << geocentric_rates_v);
 618     SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_position_v: " << geocentric_position_v);
 619     SG_LOG(SG_FLIGHT,SG_INFO,"geodetic_position_v: " << geodetic_position_v);
 620     SG_LOG(SG_FLIGHT,SG_INFO,"euler_angles_v: " << euler_angles_v);
 621
 622     SG_LOG(SG_FLIGHT,SG_INFO,"nlf: " << nlf );
 623     SG_LOG(SG_FLIGHT,SG_INFO,"v_rel_wind: " << v_rel_wind );
 624     SG_LOG(SG_FLIGHT,SG_INFO,"v_true_kts: " << v_true_kts );
 625     SG_LOG(SG_FLIGHT,SG_INFO,"v_ground_speed: " << v_ground_speed );
 626     SG_LOG(SG_FLIGHT,SG_INFO,"v_equiv_kts: " << v_equiv_kts );
 627     SG_LOG(SG_FLIGHT,SG_INFO,"v_calibrated_kts: " << v_calibrated_kts );
 628     SG_LOG(SG_FLIGHT,SG_INFO,"alpha: " << alpha );
 629     SG_LOG(SG_FLIGHT,SG_INFO,"beta: " << beta );
 630     SG_LOG(SG_FLIGHT,SG_INFO,"gamma_vert_rad: " << gamma_vert_rad );
 631     SG_LOG(SG_FLIGHT,SG_INFO,"density: " << density );
 632     SG_LOG(SG_FLIGHT,SG_INFO,"mach_number: " << mach_number );
 633     SG_LOG(SG_FLIGHT,SG_INFO,"static_pressure: " << static_pressure );
 634     SG_LOG(SG_FLIGHT,SG_INFO,"total_pressure: " << total_pressure );
 635     SG_LOG(SG_FLIGHT,SG_INFO,"dynamic_pressure: " << dynamic_pressure );
 636     SG_LOG(SG_FLIGHT,SG_INFO,"static_temperature: " << static_temperature );
 637     SG_LOG(SG_FLIGHT,SG_INFO,"total_temperature: " << total_temperature );
 638     SG_LOG(SG_FLIGHT,SG_INFO,"sea_level_radius: " << sea_level_radius );
 639     SG_LOG(SG_FLIGHT,SG_INFO,"earth_position_angle: " << earth_position_angle );
 640     SG_LOG(SG_FLIGHT,SG_INFO,"runway_altitude: " << runway_altitude );
 641     SG_LOG(SG_FLIGHT,SG_INFO,"climb_rate: " << climb_rate );
 642     SG_LOG(SG_FLIGHT,SG_INFO,"altitude_agl: " << altitude_agl );
 643 }
 644
 645 bool
 646 FGInterface::prepare_ground_cache_m(double ref_time, const double pt[3],
 647                                     double rad)
 648 {
 649   return ground_cache.prepare_ground_cache(ref_time, SGVec3d(pt), rad);
 650 }
 651
 652 bool FGInterface::prepare_ground_cache_ft(double ref_time, const double pt[3],
 653                                           double rad)
 654 {
 655   // Convert units and do the real work.
 656   SGVec3d pt_ft = SG_FEET_TO_METER*SGVec3d(pt);
 657   return ground_cache.prepare_ground_cache(ref_time, pt_ft, rad*SG_FEET_TO_METER);
 658 }
 659
 660 bool
 661 FGInterface::is_valid_m(double *ref_time, double pt[3], double *rad)
 662 {
 663   SGVec3d _pt;
 664   bool valid = ground_cache.is_valid(*ref_time, _pt, *rad);
 665   assign(pt, _pt);
 666   return valid;
 667 }
 668
 669 bool FGInterface::is_valid_ft(double *ref_time, double pt[3], double *rad)
 670 {
 671   // Convert units and do the real work.
 672   SGVec3d _pt;
 673   bool found_ground = ground_cache.is_valid(*ref_time, _pt, *rad);
 674   assign(pt, SG_METER_TO_FEET*_pt);
 675   *rad *= SG_METER_TO_FEET;
 676   return found_ground;
 677 }
 678
 679 double
 680 FGInterface::get_cat_m(double t, const double pt[3],
 681                        double end[2][3], double vel[2][3])
 682 {
 683   SGVec3d _end[2], _vel[2];
 684   double dist = ground_cache.get_cat(t, SGVec3d(pt), _end, _vel);
 685   for (int k=0; k<2; ++k) {
 686     assign( end[k], _end[k] );
 687     assign( vel[k], _vel[k] );
 688   }
 689   return dist;
 690 }
 691
 692 double
 693 FGInterface::get_cat_ft(double t, const double pt[3],
 694                         double end[2][3], double vel[2][3])
 695 {
 696   // Convert units and do the real work.
 697   SGVec3d pt_m = SG_FEET_TO_METER*SGVec3d(pt);
 698   SGVec3d _end[2], _vel[2];
 699   double dist = ground_cache.get_cat(t, pt_m, _end, _vel);
 700   for (int k=0; k<2; ++k) {
 701     assign( end[k], SG_METER_TO_FEET*_end[k] );
 702     assign( vel[k], SG_METER_TO_FEET*_vel[k] );
 703   }
 704   return dist*SG_METER_TO_FEET;
 705 }
 706
 707 bool
 708 FGInterface::get_body_m(double t, simgear::BVHNode::Id id,
 709                         double bodyToWorld[16], double linearVel[3],
 710                         double angularVel[3])
 711 {
 712   SGMatrixd _bodyToWorld;
 713   SGVec3d _linearVel, _angularVel;
 714   if (!ground_cache.get_body(t, _bodyToWorld, _linearVel, _angularVel, id))
 715     return false;
 716
 717   assign(linearVel, _linearVel);
 718   assign(angularVel, _angularVel);
 719   for (unsigned i = 0; i < 16; ++i)
 720       bodyToWorld[i] = _bodyToWorld.data()[i];
 721
 722   return true;
 723 }
 724
 725 bool
 726 FGInterface::get_agl_m(double t, const double pt[3], double max_altoff,
 727                        double contact[3], double normal[3],
 728                        double linearVel[3], double angularVel[3],
 729                        SGMaterial const*& material, simgear::BVHNode::Id& id)
 730 {
 731   SGVec3d pt_m = SGVec3d(pt) - max_altoff*ground_cache.get_down();
 732   SGVec3d _contact, _normal, _linearVel, _angularVel;
 733   material = 0;
 734   if (!ground_cache.get_agl(t, pt_m, _contact, _normal, _linearVel,
 735                             _angularVel, id, material))
 736       return false;
 737   // correct the linear velocity, since the line intersector delivers
 738   // values for the start point and the get_agl function should
 739   // traditionally deliver for the contact point
 740   _linearVel += cross(_angularVel, _contact - pt_m);
 741
 742   assign(contact, _contact);
 743   assign(normal, _normal);
 744   assign(linearVel, _linearVel);
 745   assign(angularVel, _angularVel);
 746   return true;
 747 }
 748
 749 bool
 750 FGInterface::get_agl_ft(double t, const double pt[3], double max_altoff,
 751                         double contact[3], double normal[3],
 752                         double linearVel[3], double angularVel[3],
 753                         SGMaterial const*& material, simgear::BVHNode::Id& id)
 754 {
 755   // Convert units and do the real work.
 756   SGVec3d pt_m = SGVec3d(pt) - max_altoff*ground_cache.get_down();
 757   pt_m *= SG_FEET_TO_METER;
 758   SGVec3d _contact, _normal, _linearVel, _angularVel;
 759   material = 0;
 760   if (!ground_cache.get_agl(t, pt_m, _contact, _normal, _linearVel,
 761                             _angularVel, id, material))
 762       return false;
 763   // correct the linear velocity, since the line intersector delivers
 764   // values for the start point and the get_agl function should
 765   // traditionally deliver for the contact point
 766   _linearVel += cross(_angularVel, _contact - pt_m);
 767
 768   // Convert units back ...
 769   assign( contact, SG_METER_TO_FEET*_contact );
 770   assign( normal, _normal );
 771   assign( linearVel, SG_METER_TO_FEET*_linearVel );
 772   assign( angularVel, _angularVel );
 773   return true;
 774 }
 775
 776 bool
 777 FGInterface::get_nearest_m(double t, const double pt[3], double maxDist,
 778                            double contact[3], double normal[3],
 779                            double linearVel[3], double angularVel[3],
 780                            SGMaterial const*& material,
 781                            simgear::BVHNode::Id& id)
 782 {
 783   SGVec3d _contact, _linearVel, _angularVel;
 784   if (!ground_cache.get_nearest(t, SGVec3d(pt), maxDist, _contact, _linearVel,
 785                                 _angularVel, id, material))
 786       return false;
 787
 788   assign(contact, _contact);
 789   assign(linearVel, _linearVel);
 790   assign(angularVel, _angularVel);
 791   return true;
 792 }
 793
 794 bool
 795 FGInterface::get_nearest_ft(double t, const double pt[3], double maxDist,
 796                             double contact[3], double normal[3],
 797                             double linearVel[3], double angularVel[3],
 798                             SGMaterial const*& material,
 799                             simgear::BVHNode::Id& id)
 800 {
 801   SGVec3d _contact, _linearVel, _angularVel;
 802   if (!ground_cache.get_nearest(t, SG_FEET_TO_METER*SGVec3d(pt),
 803                                 SG_FEET_TO_METER*maxDist, _contact, _linearVel,
 804                                 _angularVel, id, material))
 805       return false;
 806
 807   assign(contact, SG_METER_TO_FEET*_contact);
 808   assign(linearVel, SG_METER_TO_FEET*_linearVel);
 809   assign(angularVel, _angularVel);
 810   return true;
 811 }
 812
 813 double
 814 FGInterface::get_groundlevel_m(double lat, double lon, double alt)
 815 {
 816   return get_groundlevel_m(SGGeod::fromRadM(lon, lat, alt));
 817 }
 818
 819 double
 820 FGInterface::get_groundlevel_m(const SGGeod& geod)
 821 {
 822   // Compute the cartesian position of the given lat/lon/alt.
 823   SGVec3d pos = SGVec3d::fromGeod(geod);
 824
 825   // FIXME: how to handle t - ref_time differences ???
 826   SGVec3d cpos;
 827   double ref_time, radius;
 828   // Prepare the ground cache for that position.
 829   if (!is_valid_m(&ref_time, cpos.data(), &radius)) {
 830     bool ok = prepare_ground_cache_m(ref_time, pos.data(), 10);
 831     /// This is most likely the case when the given altitude is
 832     /// too low, try with a new altitude of 10000m, that should be
 833     /// sufficient to find a ground level below everywhere on our planet
 834     if (!ok) {
 835       pos = SGVec3d::fromGeod(SGGeod::fromRadM(geod.getLongitudeRad(), geod.getLatitudeRad(), 10000));
 836       /// If there is still no ground, return sea level radius
 837       if (!prepare_ground_cache_m(ref_time, pos.data(), 10))
 838         return 0;
 839     }
 840   } else if (radius*radius <= distSqr(pos, cpos)) {
 841     /// We reuse the old radius value, but only if it is at least 10 Meters ..
 842     if (!(10 < radius)) // Well this strange compare is nan safe
 843       radius = 10;
 844
 845     bool ok = prepare_ground_cache_m(ref_time, pos.data(), radius);
 846     /// This is most likely the case when the given altitude is
 847     /// too low, try with a new altitude of 10000m, that should be
 848     /// sufficient to find a ground level below everywhere on our planet
 849     if (!ok) {
 850       pos = SGVec3d::fromGeod(SGGeod::fromRadM(geod.getLongitudeRad(), geod.getLatitudeRad(), 10000));
 851       /// If there is still no ground, return sea level radius
 852       if (!prepare_ground_cache_m(ref_time, pos.data(), radius))
 853         return 0;
 854     }
 855   }
 856
 857   double contact[3], normal[3], vel[3], angvel[3];
 858   const SGMaterial* material;
 859   simgear::BVHNode::Id id;
 860   // Ignore the return value here, since it just tells us if
 861   // the returns stem from the groundcache or from the coarse
 862   // computations below the groundcache. The contact point is still something
 863   // valid, the normals and the other returns just contain some defaults.
 864   get_agl_m(ref_time, pos.data(), 2.0, contact, normal, vel, angvel,
 865             material, id);
 866   return SGGeod::fromCart(SGVec3d(contact)).getElevationM();
 867 }
 868
 869 bool
 870 FGInterface::caught_wire_m(double t, const double pt[4][3])
 871 {
 872   SGVec3d pt_m[4];
 873   for (int i=0; i<4; ++i)
 874     pt_m[i] = SGVec3d(pt[i]);
 875
 876   return ground_cache.caught_wire(t, pt_m);
 877 }
 878
 879 bool
 880 FGInterface::caught_wire_ft(double t, const double pt[4][3])
 881 {
 882   // Convert units and do the real work.
 883   SGVec3d pt_m[4];
 884   for (int i=0; i<4; ++i)
 885     pt_m[i] = SG_FEET_TO_METER*SGVec3d(pt[i]);
 886
 887   return ground_cache.caught_wire(t, pt_m);
 888 }
 889
 890 bool
 891 FGInterface::get_wire_ends_m(double t, double end[2][3], double vel[2][3])
 892 {
 893   SGVec3d _end[2], _vel[2];
 894   bool ret = ground_cache.get_wire_ends(t, _end, _vel);
 895   for (int k=0; k<2; ++k) {
 896     assign( end[k], _end[k] );
 897     assign( vel[k], _vel[k] );
 898   }
 899   return ret;
 900 }
 901
 902 bool
 903 FGInterface::get_wire_ends_ft(double t, double end[2][3], double vel[2][3])
 904 {
 905   // Convert units and do the real work.
 906   SGVec3d _end[2], _vel[2];
 907   bool ret = ground_cache.get_wire_ends(t, _end, _vel);
 908   for (int k=0; k<2; ++k) {
 909     assign( end[k], SG_METER_TO_FEET*_end[k] );
 910     assign( vel[k], SG_METER_TO_FEET*_vel[k] );
 911   }
 912   return ret;
 913 }
 914
 915 void
 916 FGInterface::release_wire(void)
 917 {
 918   ground_cache.release_wire();
 919 }
 920
 921 void fgToggleFDMdataLogging(void) {
 922   cur_fdm_state->ToggleDataLogging();
 923 }