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