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 <stdio.h>
  28
  29 #include <plib/sg.h>
  30
  31 #include <simgear/constants.h>
  32 #include <simgear/debug/logstream.hxx>
  33 #include <simgear/math/sg_geodesy.hxx>
  34 #include <simgear/scene/model/placement.hxx>
  35 #include <simgear/scene/material/mat.hxx>
  36 #include <simgear/timing/timestamp.hxx>
  37
  38 #include <Scenery/scenery.hxx>
  39 #include <Main/globals.hxx>
  40 #include <Main/fg_props.hxx>
  41 #include <FDM/groundcache.hxx>
  42
  43 #include "flight.hxx"
  44
  45
  46 // base_fdm_state is the internal state that is updated in integer
  47 // multiples of "dt".  This leads to "jitter" with respect to the real
  48 // world time, so we introduce cur_fdm_state which is extrapolated by
  49 // the difference between sim time and real world time
  50
  51 FGInterface *cur_fdm_state = 0;
  52 FGInterface base_fdm_state;
  53
  54 inline void init_vec(FG_VECTOR_3 vec) {
  55     vec[0] = 0.0; vec[1] = 0.0; vec[2] = 0.0;
  56 }
  57
  58 // Constructor
  59 FGInterface::FGInterface()
  60   : remainder(0)
  61 {
  62     _setup();
  63 }
  64
  65 FGInterface::FGInterface( double dt )
  66   : remainder(0)
  67 {
  68     _setup();
  69 }
  70
  71 // Destructor
  72 FGInterface::~FGInterface() {
  73     // unbind();                   // FIXME: should be called explicitly
  74 }
  75
  76
  77 int
  78 FGInterface::_calc_multiloop (double dt)
  79 {
  80   int hz = fgGetInt("/sim/model-hz");
  81   int speedup = fgGetInt("/sim/speed-up");
  82
  83   dt += remainder;
  84   remainder = 0;
  85   double ml = dt * hz;
  86   // Avoid roundoff problems by adding the roundoff itself.
  87   // ... ok, two times the roundoff to have enough room.
  88   int multiloop = int(floor(ml * (1.0 + 2.0*DBL_EPSILON)));
  89   remainder = (ml - multiloop) / hz;
  90
  91   // If we artificially inflate ml above by a tiny amount to get the
  92   // closest integer, then subtract the integer from the original
  93   // slightly smaller value, we can get a negative remainder.
  94   // Logically this should never happen, and we definitely don't want
  95   // to carry a negative remainder over to the next iteration, so
  96   // never let the remainder go below zero.
  97   //
  98   // Note: this fixes a problem where we run 1, 3, 1, 3, 1, 3... loops
  99   // of the FDM when in fact we want to run 2, 2, 2, 2, 2...
 100   if ( remainder < 0 ) { remainder = 0; }
 101
 102   return (multiloop * speedup);
 103 }
 104
 105
 106 /**
 107  * Set default values for the state of the FDM.
 108  *
 109  * This method is invoked by the constructors.
 110  */
 111 void
 112 FGInterface::_setup ()
 113 {
 114     inited = false;
 115     bound = false;
 116
 117     init_vec( d_pilot_rp_body_v );
 118     init_vec( d_cg_rp_body_v );
 119     init_vec( f_body_total_v );
 120     init_vec( f_local_total_v );
 121     init_vec( f_aero_v );
 122     init_vec( f_engine_v );
 123     init_vec( f_gear_v );
 124     init_vec( m_total_rp_v );
 125     init_vec( m_total_cg_v );
 126     init_vec( m_aero_v );
 127     init_vec( m_engine_v );
 128     init_vec( m_gear_v );
 129     init_vec( v_dot_local_v );
 130     init_vec( v_dot_body_v );
 131     init_vec( a_cg_body_v );
 132     init_vec( a_pilot_body_v );
 133     init_vec( n_cg_body_v );
 134     init_vec( n_pilot_body_v );
 135     init_vec( omega_dot_body_v );
 136     init_vec( v_local_v );
 137     init_vec( v_local_rel_ground_v );
 138     init_vec( v_local_airmass_v );
 139     init_vec( v_local_rel_airmass_v );
 140     init_vec( v_local_gust_v );
 141     init_vec( v_wind_body_v );
 142     init_vec( omega_body_v );
 143     init_vec( omega_local_v );
 144     init_vec( omega_total_v );
 145     init_vec( euler_rates_v );
 146     init_vec( geocentric_rates_v );
 147     init_vec( geocentric_position_v );
 148     init_vec( geodetic_position_v );
 149     init_vec( euler_angles_v );
 150     init_vec( d_cg_rwy_local_v );
 151     init_vec( d_cg_rwy_rwy_v );
 152     init_vec( d_pilot_rwy_local_v );
 153     init_vec( d_pilot_rwy_rwy_v );
 154     init_vec( t_local_to_body_m[0] );
 155     init_vec( t_local_to_body_m[1] );
 156     init_vec( t_local_to_body_m[2] );
 157
 158     mass=i_xx=i_yy=i_zz=i_xz=0;
 159     nlf=0;
 160     v_rel_wind=v_true_kts=v_rel_ground=v_inertial=0;
 161     v_ground_speed=v_equiv=v_equiv_kts=0;
 162     v_calibrated=v_calibrated_kts=0;
 163     gravity=0;
 164     centrifugal_relief=0;
 165     alpha=beta=alpha_dot=beta_dot=0;
 166     cos_alpha=sin_alpha=cos_beta=sin_beta=0;
 167     cos_phi=sin_phi=cos_theta=sin_theta=cos_psi=sin_psi=0;
 168     gamma_vert_rad=gamma_horiz_rad=0;
 169     sigma=density=v_sound=mach_number=0;
 170     static_pressure=total_pressure=impact_pressure=0;
 171     dynamic_pressure=0;
 172     static_temperature=total_temperature=0;
 173     sea_level_radius=earth_position_angle=0;
 174     runway_altitude=runway_latitude=runway_longitude=0;
 175     runway_heading=0;
 176     radius_to_rwy=0;
 177     climb_rate=0;
 178     sin_lat_geocentric=cos_lat_geocentric=0;
 179     sin_latitude=cos_latitude=0;
 180     sin_longitude=cos_longitude=0;
 181     altitude_agl=0;
 182 }
 183
 184 void
 185 FGInterface::init () {}
 186
 187 /**
 188  * Initialize the state of the FDM.
 189  *
 190  * Subclasses of FGInterface may do their own, additional initialization,
 191  * but there is some that is common to all.  Normally, they should call
 192  * this before they begin their own init to make sure the basic structures
 193  * are set up properly.
 194  */
 195 void
 196 FGInterface::common_init ()
 197 {
 198     SG_LOG( SG_FLIGHT, SG_INFO, "Start common FDM init" );
 199
 200     set_inited( true );
 201
 202 //     stamp();
 203 //     set_remainder( 0 );
 204
 205     // Set initial position
 206     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing position..." );
 207     double lon = fgGetDouble("/sim/presets/longitude-deg")
 208       * SGD_DEGREES_TO_RADIANS;
 209     double lat = fgGetDouble("/sim/presets/latitude-deg")
 210       * SGD_DEGREES_TO_RADIANS;
 211     double alt_ft = fgGetDouble("/sim/presets/altitude-ft");
 212     double alt_m = alt_ft * SG_FEET_TO_METER;
 213     set_Longitude( lon );
 214     set_Latitude( lat );
 215     SG_LOG( SG_FLIGHT, SG_INFO, "Checking for lon = "
 216             << lon*SGD_RADIANS_TO_DEGREES << "deg, lat = "
 217             << lat*SGD_RADIANS_TO_DEGREES << "deg, alt = "
 218             << alt_ft << "ft");
 219
 220     double ground_elev_m = get_groundlevel_m(lat, lon, alt_m);
 221     double ground_elev_ft = ground_elev_m * SG_METER_TO_FEET;
 222     _set_Runway_altitude ( ground_elev_ft );
 223     if ( fgGetBool("/sim/presets/onground") || alt_ft < ground_elev_ft ) {
 224         fgSetDouble("/position/altitude-ft", ground_elev_ft + 0.1);
 225         set_Altitude( ground_elev_ft + 0.1);
 226     } else {
 227         set_Altitude( alt_ft );
 228     }
 229
 230     // Set ground elevation
 231     SG_LOG( SG_FLIGHT, SG_INFO,
 232             "...initializing ground elevation to " << ground_elev_ft
 233             << "ft..." );
 234
 235     // Set sea-level radius
 236     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing sea-level radius..." );
 237     SG_LOG( SG_FLIGHT, SG_INFO, " lat = "
 238             << fgGetDouble("/sim/presets/latitude-deg")
 239             << " alt = " << get_Altitude() );
 240     double sea_level_radius_meters;
 241     double lat_geoc;
 242     sgGeodToGeoc( fgGetDouble("/sim/presets/latitude-deg")
 243                     * SGD_DEGREES_TO_RADIANS,
 244                   get_Altitude() * SG_FEET_TO_METER,
 245                   &sea_level_radius_meters, &lat_geoc );
 246     _set_Sea_level_radius( sea_level_radius_meters * SG_METER_TO_FEET );
 247
 248     // Set initial velocities
 249     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing velocities..." );
 250     if ( !fgHasNode("/sim/presets/speed-set") ) {
 251         set_V_calibrated_kts(0.0);
 252     } else {
 253         const string speedset = fgGetString("/sim/presets/speed-set");
 254         if ( speedset == "knots" || speedset == "KNOTS" ) {
 255             set_V_calibrated_kts( fgGetDouble("/sim/presets/airspeed-kt") );
 256         } else if ( speedset == "mach" || speedset == "MACH" ) {
 257             set_Mach_number( fgGetDouble("/sim/presets/mach") );
 258         } else if ( speedset == "UVW" || speedset == "uvw" ) {
 259             set_Velocities_Wind_Body(
 260                                      fgGetDouble("/sim/presets/uBody-fps"),
 261                                      fgGetDouble("/sim/presets/vBody-fps"),
 262                                      fgGetDouble("/sim/presets/wBody-fps") );
 263         } else if ( speedset == "NED" || speedset == "ned" ) {
 264             set_Velocities_Local(
 265                                  fgGetDouble("/sim/presets/speed-north-fps"),
 266                                  fgGetDouble("/sim/presets/speed-east-fps"),
 267                                  fgGetDouble("/sim/presets/speed-down-fps") );
 268         } else {
 269             SG_LOG( SG_FLIGHT, SG_ALERT,
 270                     "Unrecognized value for /sim/presets/speed-set: "
 271                     << speedset);
 272             set_V_calibrated_kts( 0.0 );
 273         }
 274     }
 275
 276     // Set initial Euler angles
 277     SG_LOG( SG_FLIGHT, SG_INFO, "...initializing Euler angles..." );
 278     set_Euler_Angles( fgGetDouble("/sim/presets/roll-deg")
 279                         * SGD_DEGREES_TO_RADIANS,
 280                       fgGetDouble("/sim/presets/pitch-deg")
 281                         * SGD_DEGREES_TO_RADIANS,
 282                       fgGetDouble("/sim/presets/heading-deg")
 283                         * SGD_DEGREES_TO_RADIANS );
 284
 285     SG_LOG( SG_FLIGHT, SG_INFO, "End common FDM init" );
 286 }
 287
 288
 289 /**
 290  * Bind getters and setters to properties.
 291  *
 292  * The bind() method will be invoked after init().  Note that unlike
 293  * the usual implementations of FGSubsystem::bind(), this method does
 294  * not automatically pick up existing values for the properties at
 295  * bind time; instead, all values are set explicitly in the init()
 296  * method.
 297  */
 298 void
 299 FGInterface::bind ()
 300 {
 301   bound = true;
 302
 303                                 // Time management (read-only)
 304 //   fgTie("/fdm/time/delta_t", this,
 305 //         &FGInterface::get_delta_t); // read-only
 306 //   fgTie("/fdm/time/elapsed", this,
 307 //         &FGInterface::get_elapsed); // read-only
 308 //   fgTie("/fdm/time/remainder", this,
 309 //         &FGInterface::get_remainder); // read-only
 310 //   fgTie("/fdm/time/multi_loop", this,
 311 //         &FGInterface::get_multi_loop); // read-only
 312
 313                         // Aircraft position
 314   fgTie("/position/latitude-deg", this,
 315         &FGInterface::get_Latitude_deg,
 316         &FGInterface::set_Latitude_deg,
 317         false);
 318   fgSetArchivable("/position/latitude-deg");
 319   fgTie("/position/longitude-deg", this,
 320         &FGInterface::get_Longitude_deg,
 321         &FGInterface::set_Longitude_deg,
 322         false);
 323   fgSetArchivable("/position/longitude-deg");
 324   fgTie("/position/altitude-ft", this,
 325         &FGInterface::get_Altitude,
 326         &FGInterface::set_Altitude,
 327         false);
 328   fgSetArchivable("/position/altitude-ft");
 329   fgTie("/position/altitude-agl-ft", this,
 330         &FGInterface::get_Altitude_AGL); // read-only
 331   fgSetArchivable("/position/ground-elev-ft");
 332   fgTie("/position/ground-elev-ft", this,
 333         &FGInterface::get_Runway_altitude); // read-only
 334   fgSetArchivable("/position/ground-elev-m");
 335   fgTie("/position/ground-elev-m", this,
 336         &FGInterface::get_Runway_altitude_m); // read-only
 337   fgTie("/environment/ground-elevation-m", this,
 338         &FGInterface::get_Runway_altitude_m); // read-only
 339   fgSetArchivable("/position/sea-level-radius-ft");
 340   fgTie("/position/sea-level-radius-ft", this,
 341         &FGInterface::get_Sea_level_radius); // read-only
 342
 343                                 // Orientation
 344   fgTie("/orientation/roll-deg", this,
 345         &FGInterface::get_Phi_deg,
 346         &FGInterface::set_Phi_deg);
 347   fgSetArchivable("/orientation/roll-deg");
 348   fgTie("/orientation/pitch-deg", this,
 349         &FGInterface::get_Theta_deg,
 350         &FGInterface::set_Theta_deg);
 351   fgSetArchivable("/orientation/pitch-deg");
 352   fgTie("/orientation/heading-deg", this,
 353         &FGInterface::get_Psi_deg,
 354         &FGInterface::set_Psi_deg);
 355   fgSetArchivable("/orientation/heading-deg");
 356
 357   // Body-axis "euler rates" (rotation speed, but in a funny
 358   // representation).
 359   fgTie("/orientation/roll-rate-degps", this,
 360         &FGInterface::get_Phi_dot_degps);
 361   fgTie("/orientation/pitch-rate-degps", this,
 362         &FGInterface::get_Theta_dot_degps);
 363   fgTie("/orientation/yaw-rate-degps", this,
 364         &FGInterface::get_Psi_dot_degps);
 365
 366                                 // Ground speed knots
 367   fgTie("/velocities/groundspeed-kt", this,
 368         &FGInterface::get_V_ground_speed_kt);
 369
 370                                 // Calibrated airspeed
 371   fgTie("/velocities/airspeed-kt", this,
 372         &FGInterface::get_V_calibrated_kts,
 373         &FGInterface::set_V_calibrated_kts,
 374         false);
 375
 376                                 // Mach number
 377   fgTie("/velocities/mach", this,
 378         &FGInterface::get_Mach_number,
 379         &FGInterface::set_Mach_number,
 380         false);
 381
 382                                 // Local velocities
 383 //   fgTie("/velocities/speed-north-fps", this,
 384 //      &FGInterface::get_V_north,
 385 //      &FGInterface::set_V_north);
 386 //   fgSetArchivable("/velocities/speed-north-fps");
 387 //   fgTie("/velocities/speed-east-fps", this,
 388 //      &FGInterface::get_V_east,
 389 //      &FGInterface::set_V_east);
 390 //   fgSetArchivable("/velocities/speed-east-fps");
 391 //   fgTie("/velocities/speed-down-fps", this,
 392 //      &FGInterface::get_V_down,
 393 //      &FGInterface::set_V_down);
 394 //   fgSetArchivable("/velocities/speed-down-fps");
 395                                 // FIXME: Temporarily read-only, until the
 396                                 // incompatibilities between JSBSim and
 397                                 // LaRCSim are fixed (LaRCSim adds the
 398                                 // earth's rotation to the east velocity).
 399   fgTie("/velocities/speed-north-fps", this,
 400         &FGInterface::get_V_north);
 401   fgTie("/velocities/speed-east-fps", this,
 402         &FGInterface::get_V_east);
 403   fgTie("/velocities/speed-down-fps", this,
 404         &FGInterface::get_V_down);
 405
 406                                 // Relative wind
 407                                 // FIXME: temporarily archivable, until
 408                                 // the NED problem is fixed.
 409   fgTie("/velocities/uBody-fps", this,
 410         &FGInterface::get_uBody,
 411         &FGInterface::set_uBody,
 412         false);
 413   fgSetArchivable("/velocities/uBody-fps");
 414   fgTie("/velocities/vBody-fps", this,
 415         &FGInterface::get_vBody,
 416         &FGInterface::set_vBody,
 417         false);
 418   fgSetArchivable("/velocities/vBody-fps");
 419   fgTie("/velocities/wBody-fps", this,
 420         &FGInterface::get_wBody,
 421         &FGInterface::set_wBody,
 422         false);
 423   fgSetArchivable("/velocities/wBody-fps");
 424
 425                                 // Climb and slip (read-only)
 426   fgTie("/velocities/vertical-speed-fps", this,
 427         &FGInterface::get_Climb_Rate,
 428   &FGInterface::set_Climb_Rate );
 429   fgTie("/velocities/glideslope", this,
 430   &FGInterface::get_Gamma_vert_rad,
 431   &FGInterface::set_Gamma_vert_rad );
 432   fgTie("/orientation/side-slip-rad", this,
 433         &FGInterface::get_Beta); // read-only
 434   fgTie("/orientation/side-slip-deg", this,
 435   &FGInterface::get_Beta_deg); // read-only
 436   fgTie("/orientation/alpha-deg", this,
 437   &FGInterface::get_Alpha_deg); // read-only
 438   fgTie("/accelerations/nlf", this,
 439   &FGInterface::get_Nlf); // read-only
 440
 441                                 // NED accelerations
 442   fgTie("/accelerations/ned/north-accel-fps_sec",
 443         this, &FGInterface::get_V_dot_north);
 444   fgTie("/accelerations/ned/east-accel-fps_sec",
 445         this, &FGInterface::get_V_dot_east);
 446   fgTie("/accelerations/ned/down-accel-fps_sec",
 447         this, &FGInterface::get_V_dot_down);
 448
 449                                 // Pilot accelerations
 450   fgTie("/accelerations/pilot/x-accel-fps_sec",
 451         this, &FGInterface::get_A_X_pilot);
 452   fgTie("/accelerations/pilot/y-accel-fps_sec",
 453         this, &FGInterface::get_A_Y_pilot);
 454   fgTie("/accelerations/pilot/z-accel-fps_sec",
 455         this, &FGInterface::get_A_Z_pilot);
 456
 457 }
 458
 459
 460 /**
 461  * Unbind any properties bound to this FDM.
 462  *
 463  * This method allows the FDM to release properties so that a new
 464  * FDM can bind them instead.
 465  */
 466 void
 467 FGInterface::unbind ()
 468 {
 469   bound = false;
 470
 471   // fgUntie("/fdm/time/delta_t");
 472   // fgUntie("/fdm/time/elapsed");
 473   // fgUntie("/fdm/time/remainder");
 474   // fgUntie("/fdm/time/multi_loop");
 475   fgUntie("/position/latitude-deg");
 476   fgUntie("/position/longitude-deg");
 477   fgUntie("/position/altitude-ft");
 478   fgUntie("/position/altitude-agl-ft");
 479   fgUntie("/position/ground-elev-ft");
 480   fgUntie("/position/ground-elev-m");
 481   fgUntie("/environment/ground-elevation-m");
 482   fgUntie("/position/sea-level-radius-ft");
 483   fgUntie("/orientation/roll-deg");
 484   fgUntie("/orientation/pitch-deg");
 485   fgUntie("/orientation/heading-deg");
 486   fgUntie("/orientation/roll-rate-degps");
 487   fgUntie("/orientation/pitch-rate-degps");
 488   fgUntie("/orientation/yaw-rate-degps");
 489   fgUntie("/orientation/side-slip-rad");
 490   fgUntie("/orientation/side-slip-deg");
 491   fgUntie("/orientation/alpha-deg");
 492   fgUntie("/velocities/airspeed-kt");
 493   fgUntie("/velocities/groundspeed-kt");
 494   fgUntie("/velocities/mach");
 495   fgUntie("/velocities/speed-north-fps");
 496   fgUntie("/velocities/speed-east-fps");
 497   fgUntie("/velocities/speed-down-fps");
 498   fgUntie("/velocities/uBody-fps");
 499   fgUntie("/velocities/vBody-fps");
 500   fgUntie("/velocities/wBody-fps");
 501   fgUntie("/velocities/vertical-speed-fps");
 502   fgUntie("/velocities/glideslope");
 503   fgUntie("/accelerations/nlf");
 504   fgUntie("/accelerations/pilot/x-accel-fps_sec");
 505   fgUntie("/accelerations/pilot/y-accel-fps_sec");
 506   fgUntie("/accelerations/pilot/z-accel-fps_sec");
 507   fgUntie("/accelerations/ned/north-accel-fps_sec");
 508   fgUntie("/accelerations/ned/east-accel-fps_sec");
 509   fgUntie("/accelerations/ned/down-accel-fps_sec");
 510 }
 511
 512 /**
 513  * Update the state of the FDM (i.e. run the equations of motion).
 514  */
 515 void
 516 FGInterface::update (double dt)
 517 {
 518     SG_LOG(SG_FLIGHT, SG_ALERT, "dummy update() ... SHOULDN'T BE CALLED!");
 519 }
 520
 521
 522 void FGInterface::_updateGeodeticPosition( double lat, double lon, double alt )
 523 {
 524     double lat_geoc, sl_radius;
 525
 526     // cout << "starting sea level rad = " << get_Sea_level_radius() << endl;
 527
 528     sgGeodToGeoc( lat, alt * SG_FEET_TO_METER, &sl_radius, &lat_geoc );
 529
 530     SG_LOG( SG_FLIGHT, SG_DEBUG, "lon = " << lon
 531             << " lat_geod = " << lat
 532             << " lat_geoc = " << lat_geoc
 533             << " alt = " << alt
 534             << " sl_radius = " << sl_radius * SG_METER_TO_FEET
 535             << " Equator = " << SG_EQUATORIAL_RADIUS_FT );
 536
 537     _set_Geocentric_Position( lat_geoc, lon,
 538                               sl_radius * SG_METER_TO_FEET + alt );
 539
 540     _set_Geodetic_Position( lat, lon, alt );
 541
 542     _set_Sea_level_radius( sl_radius * SG_METER_TO_FEET );
 543     _update_ground_elev_at_pos();
 544
 545     _set_sin_lat_geocentric( lat_geoc );
 546     _set_cos_lat_geocentric( lat_geoc );
 547
 548     _set_sin_cos_longitude( lon );
 549
 550     _set_sin_cos_latitude( lat );
 551 }
 552
 553
 554 void FGInterface::_updateGeocentricPosition( double lat_geoc, double lon,
 555                                              double alt )
 556 {
 557     double lat_geod, tmp_alt, sl_radius1, sl_radius2, tmp_lat_geoc;
 558
 559     // cout << "starting sea level rad = " << get_Sea_level_radius() << endl;
 560
 561     sgGeocToGeod( lat_geoc, ( get_Sea_level_radius() + alt ) * SG_FEET_TO_METER,
 562                   &lat_geod, &tmp_alt, &sl_radius1 );
 563     sgGeodToGeoc( lat_geod, alt * SG_FEET_TO_METER, &sl_radius2, &tmp_lat_geoc );
 564
 565     SG_LOG( SG_FLIGHT, SG_DEBUG, "lon = " << lon
 566             << " lat_geod = " << lat_geod
 567             << " lat_geoc = " << lat_geoc
 568             << " alt = " << alt
 569             << " tmp_alt = " << tmp_alt * SG_METER_TO_FEET
 570             << " sl_radius1 = " << sl_radius1 * SG_METER_TO_FEET
 571             << " sl_radius2 = " << sl_radius2 * SG_METER_TO_FEET
 572             << " Equator = " << SG_EQUATORIAL_RADIUS_FT );
 573
 574     _set_Geocentric_Position( lat_geoc, lon,
 575                               sl_radius2 * SG_METER_TO_FEET + alt );
 576
 577     _set_Geodetic_Position( lat_geod, lon, alt );
 578
 579     _set_Sea_level_radius( sl_radius2 * SG_METER_TO_FEET );
 580     _update_ground_elev_at_pos();
 581
 582     _set_sin_lat_geocentric( lat_geoc );
 583     _set_cos_lat_geocentric( lat_geoc );
 584
 585     _set_sin_cos_longitude( lon );
 586
 587     _set_sin_cos_latitude( lat_geod );
 588 }
 589
 590 void FGInterface::_update_ground_elev_at_pos( void ) {
 591     double lat = get_Latitude();
 592     double lon = get_Longitude();
 593     double alt_m = get_Altitude()*SG_FEET_TO_METER;
 594     double groundlevel_m = get_groundlevel_m(lat, lon, alt_m);
 595     _set_Runway_altitude( groundlevel_m * SG_METER_TO_FEET );
 596 }
 597
 598 // Extrapolate fdm based on time_offset (in usec)
 599 void FGInterface::extrapolate( int time_offset ) {
 600     double dt = time_offset / 1000000.0;
 601
 602     // -dw- metrowerks complains about ambiguous access, not critical
 603     // to keep this ;)
 604 #ifndef __MWERKS__
 605     SG_LOG(SG_FLIGHT, SG_INFO, "extrapolating FDM by dt = " << dt);
 606 #endif
 607
 608     double lat = geodetic_position_v[0] + geocentric_rates_v[0] * dt;
 609     double lat_geoc = geocentric_position_v[0] + geocentric_rates_v[0] * dt;
 610
 611     double lon = geodetic_position_v[1] + geocentric_rates_v[1] * dt;
 612     double lon_geoc = geocentric_position_v[1] + geocentric_rates_v[1] * dt;
 613
 614     double alt = geodetic_position_v[2] + geocentric_rates_v[2] * dt;
 615     double radius = geocentric_position_v[2] + geocentric_rates_v[2] * dt;
 616
 617     geodetic_position_v[0] = lat;
 618     geocentric_position_v[0] = lat_geoc;
 619
 620     geodetic_position_v[1] = lon;
 621     geocentric_position_v[1] = lon_geoc;
 622
 623     geodetic_position_v[2] = alt;
 624     geocentric_position_v[2] = radius;
 625 }
 626
 627 // Positions
 628 void FGInterface::set_Latitude(double lat) {
 629     geodetic_position_v[0] = lat;
 630 }
 631
 632 void FGInterface::set_Longitude(double lon) {
 633     geodetic_position_v[1] = lon;
 634 }
 635
 636 void FGInterface::set_Altitude(double alt) {
 637     geodetic_position_v[2] = alt;
 638 }
 639
 640 void FGInterface::set_AltitudeAGL(double altagl) {
 641     altitude_agl=altagl;
 642 }
 643
 644 // Velocities
 645 void FGInterface::set_V_calibrated_kts(double vc) {
 646     v_calibrated_kts = vc;
 647 }
 648
 649 void FGInterface::set_Mach_number(double mach) {
 650     mach_number = mach;
 651 }
 652
 653 void FGInterface::set_Velocities_Local( double north,
 654                                         double east,
 655                                         double down ){
 656     v_local_v[0] = north;
 657     v_local_v[1] = east;
 658     v_local_v[2] = down;
 659 }
 660
 661 void FGInterface::set_Velocities_Wind_Body( double u,
 662                                             double v,
 663                                             double w){
 664     v_wind_body_v[0] = u;
 665     v_wind_body_v[1] = v;
 666     v_wind_body_v[2] = w;
 667 }
 668
 669 // Euler angles
 670 void FGInterface::set_Euler_Angles( double phi,
 671                                     double theta,
 672                                     double psi ) {
 673     euler_angles_v[0] = phi;
 674     euler_angles_v[1] = theta;
 675     euler_angles_v[2] = psi;
 676 }
 677
 678 // Flight Path
 679 void FGInterface::set_Climb_Rate( double roc) {
 680     climb_rate = roc;
 681 }
 682
 683 void FGInterface::set_Gamma_vert_rad( double gamma) {
 684     gamma_vert_rad = gamma;
 685 }
 686
 687 void FGInterface::set_Static_pressure(double p) { static_pressure = p; }
 688 void FGInterface::set_Static_temperature(double T) { static_temperature = T; }
 689 void FGInterface::set_Density(double rho) { density = rho; }
 690
 691 void FGInterface::set_Velocities_Local_Airmass (double wnorth,
 692                                                 double weast,
 693                                                 double wdown ) {
 694     v_local_airmass_v[0] = wnorth;
 695     v_local_airmass_v[1] = weast;
 696     v_local_airmass_v[2] = wdown;
 697 }
 698
 699
 700 void FGInterface::_busdump(void) {
 701
 702     SG_LOG(SG_FLIGHT,SG_INFO,"d_pilot_rp_body_v[3]: " << d_pilot_rp_body_v[0] << ", " << d_pilot_rp_body_v[1] << ", " << d_pilot_rp_body_v[2]);
 703     SG_LOG(SG_FLIGHT,SG_INFO,"d_cg_rp_body_v[3]: " << d_cg_rp_body_v[0] << ", " << d_cg_rp_body_v[1] << ", " << d_cg_rp_body_v[2]);
 704     SG_LOG(SG_FLIGHT,SG_INFO,"f_body_total_v[3]: " << f_body_total_v[0] << ", " << f_body_total_v[1] << ", " << f_body_total_v[2]);
 705     SG_LOG(SG_FLIGHT,SG_INFO,"f_local_total_v[3]: " << f_local_total_v[0] << ", " << f_local_total_v[1] << ", " << f_local_total_v[2]);
 706     SG_LOG(SG_FLIGHT,SG_INFO,"f_aero_v[3]: " << f_aero_v[0] << ", " << f_aero_v[1] << ", " << f_aero_v[2]);
 707     SG_LOG(SG_FLIGHT,SG_INFO,"f_engine_v[3]: " << f_engine_v[0] << ", " << f_engine_v[1] << ", " << f_engine_v[2]);
 708     SG_LOG(SG_FLIGHT,SG_INFO,"f_gear_v[3]: " << f_gear_v[0] << ", " << f_gear_v[1] << ", " << f_gear_v[2]);
 709     SG_LOG(SG_FLIGHT,SG_INFO,"m_total_rp_v[3]: " << m_total_rp_v[0] << ", " << m_total_rp_v[1] << ", " << m_total_rp_v[2]);
 710     SG_LOG(SG_FLIGHT,SG_INFO,"m_total_cg_v[3]: " << m_total_cg_v[0] << ", " << m_total_cg_v[1] << ", " << m_total_cg_v[2]);
 711     SG_LOG(SG_FLIGHT,SG_INFO,"m_aero_v[3]: " << m_aero_v[0] << ", " << m_aero_v[1] << ", " << m_aero_v[2]);
 712     SG_LOG(SG_FLIGHT,SG_INFO,"m_engine_v[3]: " << m_engine_v[0] << ", " << m_engine_v[1] << ", " << m_engine_v[2]);
 713     SG_LOG(SG_FLIGHT,SG_INFO,"m_gear_v[3]: " << m_gear_v[0] << ", " << m_gear_v[1] << ", " << m_gear_v[2]);
 714     SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_local_v[3]: " << v_dot_local_v[0] << ", " << v_dot_local_v[1] << ", " << v_dot_local_v[2]);
 715     SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_body_v[3]: " << v_dot_body_v[0] << ", " << v_dot_body_v[1] << ", " << v_dot_body_v[2]);
 716     SG_LOG(SG_FLIGHT,SG_INFO,"a_cg_body_v[3]: " << a_cg_body_v[0] << ", " << a_cg_body_v[1] << ", " << a_cg_body_v[2]);
 717     SG_LOG(SG_FLIGHT,SG_INFO,"a_pilot_body_v[3]: " << a_pilot_body_v[0] << ", " << a_pilot_body_v[1] << ", " << a_pilot_body_v[2]);
 718     SG_LOG(SG_FLIGHT,SG_INFO,"n_cg_body_v[3]: " << n_cg_body_v[0] << ", " << n_cg_body_v[1] << ", " << n_cg_body_v[2]);
 719     SG_LOG(SG_FLIGHT,SG_INFO,"n_pilot_body_v[3]: " << n_pilot_body_v[0] << ", " << n_pilot_body_v[1] << ", " << n_pilot_body_v[2]);
 720     SG_LOG(SG_FLIGHT,SG_INFO,"omega_dot_body_v[3]: " << omega_dot_body_v[0] << ", " << omega_dot_body_v[1] << ", " << omega_dot_body_v[2]);
 721     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_v[3]: " << v_local_v[0] << ", " << v_local_v[1] << ", " << v_local_v[2]);
 722     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_rel_ground_v[3]: " << v_local_rel_ground_v[0] << ", " << v_local_rel_ground_v[1] << ", " << v_local_rel_ground_v[2]);
 723     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_airmass_v[3]: " << v_local_airmass_v[0] << ", " << v_local_airmass_v[1] << ", " << v_local_airmass_v[2]);
 724     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_rel_airmass_v[3]: " << v_local_rel_airmass_v[0] << ", " << v_local_rel_airmass_v[1] << ", " << v_local_rel_airmass_v[2]);
 725     SG_LOG(SG_FLIGHT,SG_INFO,"v_local_gust_v[3]: " << v_local_gust_v[0] << ", " << v_local_gust_v[1] << ", " << v_local_gust_v[2]);
 726     SG_LOG(SG_FLIGHT,SG_INFO,"v_wind_body_v[3]: " << v_wind_body_v[0] << ", " << v_wind_body_v[1] << ", " << v_wind_body_v[2]);
 727     SG_LOG(SG_FLIGHT,SG_INFO,"omega_body_v[3]: " << omega_body_v[0] << ", " << omega_body_v[1] << ", " << omega_body_v[2]);
 728     SG_LOG(SG_FLIGHT,SG_INFO,"omega_local_v[3]: " << omega_local_v[0] << ", " << omega_local_v[1] << ", " << omega_local_v[2]);
 729     SG_LOG(SG_FLIGHT,SG_INFO,"omega_total_v[3]: " << omega_total_v[0] << ", " << omega_total_v[1] << ", " << omega_total_v[2]);
 730     SG_LOG(SG_FLIGHT,SG_INFO,"euler_rates_v[3]: " << euler_rates_v[0] << ", " << euler_rates_v[1] << ", " << euler_rates_v[2]);
 731     SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_rates_v[3]: " << geocentric_rates_v[0] << ", " << geocentric_rates_v[1] << ", " << geocentric_rates_v[2]);
 732     SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_position_v[3]: " << geocentric_position_v[0] << ", " << geocentric_position_v[1] << ", " << geocentric_position_v[2]);
 733     SG_LOG(SG_FLIGHT,SG_INFO,"geodetic_position_v[3]: " << geodetic_position_v[0] << ", " << geodetic_position_v[1] << ", " << geodetic_position_v[2]);
 734     SG_LOG(SG_FLIGHT,SG_INFO,"euler_angles_v[3]: " << euler_angles_v[0] << ", " << euler_angles_v[1] << ", " << euler_angles_v[2]);
 735     SG_LOG(SG_FLIGHT,SG_INFO,"d_cg_rwy_local_v[3]: " << d_cg_rwy_local_v[0] << ", " << d_cg_rwy_local_v[1] << ", " << d_cg_rwy_local_v[2]);
 736     SG_LOG(SG_FLIGHT,SG_INFO,"d_cg_rwy_rwy_v[3]: " << d_cg_rwy_rwy_v[0] << ", " << d_cg_rwy_rwy_v[1] << ", " << d_cg_rwy_rwy_v[2]);
 737     SG_LOG(SG_FLIGHT,SG_INFO,"d_pilot_rwy_local_v[3]: " << d_pilot_rwy_local_v[0] << ", " << d_pilot_rwy_local_v[1] << ", " << d_pilot_rwy_local_v[2]);
 738     SG_LOG(SG_FLIGHT,SG_INFO,"d_pilot_rwy_rwy_v[3]: " << d_pilot_rwy_rwy_v[0] << ", " << d_pilot_rwy_rwy_v[1] << ", " << d_pilot_rwy_rwy_v[2]);
 739
 740     SG_LOG(SG_FLIGHT,SG_INFO,"t_local_to_body_m[0][3]: " << t_local_to_body_m[0][0] << ", " << t_local_to_body_m[0][1] << ", " << t_local_to_body_m[0][2]);
 741     SG_LOG(SG_FLIGHT,SG_INFO,"t_local_to_body_m[1][3]: " << t_local_to_body_m[1][0] << ", " << t_local_to_body_m[1][1] << ", " << t_local_to_body_m[1][2]);
 742     SG_LOG(SG_FLIGHT,SG_INFO,"t_local_to_body_m[2][3]: " << t_local_to_body_m[2][0] << ", " << t_local_to_body_m[2][1] << ", " << t_local_to_body_m[2][2]);
 743
 744     SG_LOG(SG_FLIGHT,SG_INFO,"mass: " << mass );
 745     SG_LOG(SG_FLIGHT,SG_INFO,"i_xx: " << i_xx );
 746     SG_LOG(SG_FLIGHT,SG_INFO,"i_yy: " << i_yy );
 747     SG_LOG(SG_FLIGHT,SG_INFO,"i_zz: " << i_zz );
 748     SG_LOG(SG_FLIGHT,SG_INFO,"i_xz: " << i_xz );
 749     SG_LOG(SG_FLIGHT,SG_INFO,"nlf: " << nlf );
 750     SG_LOG(SG_FLIGHT,SG_INFO,"v_rel_wind: " << v_rel_wind );
 751     SG_LOG(SG_FLIGHT,SG_INFO,"v_true_kts: " << v_true_kts );
 752     SG_LOG(SG_FLIGHT,SG_INFO,"v_rel_ground: " << v_rel_ground );
 753     SG_LOG(SG_FLIGHT,SG_INFO,"v_inertial: " << v_inertial );
 754     SG_LOG(SG_FLIGHT,SG_INFO,"v_ground_speed: " << v_ground_speed );
 755     SG_LOG(SG_FLIGHT,SG_INFO,"v_equiv: " << v_equiv );
 756     SG_LOG(SG_FLIGHT,SG_INFO,"v_equiv_kts: " << v_equiv_kts );
 757     SG_LOG(SG_FLIGHT,SG_INFO,"v_calibrated: " << v_calibrated );
 758     SG_LOG(SG_FLIGHT,SG_INFO,"v_calibrated_kts: " << v_calibrated_kts );
 759     SG_LOG(SG_FLIGHT,SG_INFO,"gravity: " << gravity );
 760     SG_LOG(SG_FLIGHT,SG_INFO,"centrifugal_relief: " << centrifugal_relief );
 761     SG_LOG(SG_FLIGHT,SG_INFO,"alpha: " << alpha );
 762     SG_LOG(SG_FLIGHT,SG_INFO,"beta: " << beta );
 763     SG_LOG(SG_FLIGHT,SG_INFO,"alpha_dot: " << alpha_dot );
 764     SG_LOG(SG_FLIGHT,SG_INFO,"beta_dot: " << beta_dot );
 765     SG_LOG(SG_FLIGHT,SG_INFO,"cos_alpha: " << cos_alpha );
 766     SG_LOG(SG_FLIGHT,SG_INFO,"sin_alpha: " << sin_alpha );
 767     SG_LOG(SG_FLIGHT,SG_INFO,"cos_beta: " << cos_beta );
 768     SG_LOG(SG_FLIGHT,SG_INFO,"sin_beta: " << sin_beta );
 769     SG_LOG(SG_FLIGHT,SG_INFO,"cos_phi: " << cos_phi );
 770     SG_LOG(SG_FLIGHT,SG_INFO,"sin_phi: " << sin_phi );
 771     SG_LOG(SG_FLIGHT,SG_INFO,"cos_theta: " << cos_theta );
 772     SG_LOG(SG_FLIGHT,SG_INFO,"sin_theta: " << sin_theta );
 773     SG_LOG(SG_FLIGHT,SG_INFO,"cos_psi: " << cos_psi );
 774     SG_LOG(SG_FLIGHT,SG_INFO,"sin_psi: " << sin_psi );
 775     SG_LOG(SG_FLIGHT,SG_INFO,"gamma_vert_rad: " << gamma_vert_rad );
 776     SG_LOG(SG_FLIGHT,SG_INFO,"gamma_horiz_rad: " << gamma_horiz_rad );
 777     SG_LOG(SG_FLIGHT,SG_INFO,"sigma: " << sigma );
 778     SG_LOG(SG_FLIGHT,SG_INFO,"density: " << density );
 779     SG_LOG(SG_FLIGHT,SG_INFO,"v_sound: " << v_sound );
 780     SG_LOG(SG_FLIGHT,SG_INFO,"mach_number: " << mach_number );
 781     SG_LOG(SG_FLIGHT,SG_INFO,"static_pressure: " << static_pressure );
 782     SG_LOG(SG_FLIGHT,SG_INFO,"total_pressure: " << total_pressure );
 783     SG_LOG(SG_FLIGHT,SG_INFO,"impact_pressure: " << impact_pressure );
 784     SG_LOG(SG_FLIGHT,SG_INFO,"dynamic_pressure: " << dynamic_pressure );
 785     SG_LOG(SG_FLIGHT,SG_INFO,"static_temperature: " << static_temperature );
 786     SG_LOG(SG_FLIGHT,SG_INFO,"total_temperature: " << total_temperature );
 787     SG_LOG(SG_FLIGHT,SG_INFO,"sea_level_radius: " << sea_level_radius );
 788     SG_LOG(SG_FLIGHT,SG_INFO,"earth_position_angle: " << earth_position_angle );
 789     SG_LOG(SG_FLIGHT,SG_INFO,"runway_altitude: " << runway_altitude );
 790     SG_LOG(SG_FLIGHT,SG_INFO,"runway_latitude: " << runway_latitude );
 791     SG_LOG(SG_FLIGHT,SG_INFO,"runway_longitude: " << runway_longitude );
 792     SG_LOG(SG_FLIGHT,SG_INFO,"runway_heading: " << runway_heading );
 793     SG_LOG(SG_FLIGHT,SG_INFO,"radius_to_rwy: " << radius_to_rwy );
 794     SG_LOG(SG_FLIGHT,SG_INFO,"climb_rate: " << climb_rate );
 795     SG_LOG(SG_FLIGHT,SG_INFO,"sin_lat_geocentric: " << sin_lat_geocentric );
 796     SG_LOG(SG_FLIGHT,SG_INFO,"cos_lat_geocentric: " << cos_lat_geocentric );
 797     SG_LOG(SG_FLIGHT,SG_INFO,"sin_longitude: " << sin_longitude );
 798     SG_LOG(SG_FLIGHT,SG_INFO,"cos_longitude: " << cos_longitude );
 799     SG_LOG(SG_FLIGHT,SG_INFO,"sin_latitude: " << sin_latitude );
 800     SG_LOG(SG_FLIGHT,SG_INFO,"cos_latitude: " << cos_latitude );
 801     SG_LOG(SG_FLIGHT,SG_INFO,"altitude_agl: " << altitude_agl );
 802 }
 803
 804 bool
 805 FGInterface::prepare_ground_cache_m(double ref_time, const double pt[3],
 806                                     double rad)
 807 {
 808   return ground_cache.prepare_ground_cache(ref_time, SGVec3d(pt), rad);
 809 }
 810
 811 bool FGInterface::prepare_ground_cache_ft(double ref_time, const double pt[3],
 812                                           double rad)
 813 {
 814   // Convert units and do the real work.
 815   SGVec3d pt_ft = SG_FEET_TO_METER*SGVec3d(pt);
 816   return ground_cache.prepare_ground_cache(ref_time, pt_ft, rad*SG_FEET_TO_METER);
 817 }
 818
 819 bool
 820 FGInterface::is_valid_m(double *ref_time, double pt[3], double *rad)
 821 {
 822   SGVec3d _pt;
 823   bool valid = ground_cache.is_valid(*ref_time, _pt, *rad);
 824   sgdCopyVec3(pt, _pt.data());
 825   return valid;
 826 }
 827
 828 bool FGInterface::is_valid_ft(double *ref_time, double pt[3], double *rad)
 829 {
 830   // Convert units and do the real work.
 831   SGVec3d _pt;
 832   bool found_ground = ground_cache.is_valid(*ref_time, _pt, *rad);
 833   sgdScaleVec3(pt, _pt.data(), SG_METER_TO_FEET);
 834   *rad *= SG_METER_TO_FEET;
 835   return found_ground;
 836 }
 837
 838 double
 839 FGInterface::get_cat_m(double t, const double pt[3],
 840                        double end[2][3], double vel[2][3])
 841 {
 842   SGVec3d _end[2], _vel[2];
 843   double dist = ground_cache.get_cat(t, SGVec3d(pt), _end, _vel);
 844   for (int k=0; k<2; ++k) {
 845     sgdCopyVec3( end[k], _end[k].data() );
 846     sgdCopyVec3( vel[k], _vel[k].data() );
 847   }
 848   return dist;
 849 }
 850
 851 double
 852 FGInterface::get_cat_ft(double t, const double pt[3],
 853                         double end[2][3], double vel[2][3])
 854 {
 855   // Convert units and do the real work.
 856   SGVec3d pt_m = SG_FEET_TO_METER*SGVec3d(pt);
 857   SGVec3d _end[2], _vel[2];
 858   double dist = ground_cache.get_cat(t, pt_m, _end, _vel);
 859   for (int k=0; k<2; ++k) {
 860     sgdScaleVec3( end[k], _end[k].data(), SG_METER_TO_FEET );
 861     sgdScaleVec3( vel[k], _vel[k].data(), SG_METER_TO_FEET );
 862   }
 863   return dist*SG_METER_TO_FEET;
 864 }
 865
 866 // Legacy interface just kept because of JSBSim
 867 bool
 868 FGInterface::get_agl_m(double t, const double pt[3],
 869                        double contact[3], double normal[3], double vel[3],
 870                        int *type, double *loadCapacity,
 871                        double *frictionFactor, double *agl)
 872 {
 873   const SGMaterial* material;
 874   SGVec3d _contact, _normal, _vel;
 875   bool ret = ground_cache.get_agl(t, SGVec3d(pt), 2.0, _contact, _normal,
 876                                   _vel, type, &material, agl);
 877   sgdCopyVec3(contact, _contact.data());
 878   sgdCopyVec3(normal, _normal.data());
 879   sgdCopyVec3(vel, _vel.data());
 880   if (material) {
 881     *loadCapacity = material->get_load_resistance();
 882     *frictionFactor = material->get_friction_factor();
 883
 884   } else {
 885     *loadCapacity = DBL_MAX;
 886     *frictionFactor = 1.0;
 887   }
 888   return ret;
 889 }
 890
 891 bool
 892 FGInterface::get_agl_m(double t, const double pt[3],
 893                        double contact[3], double normal[3], double vel[3],
 894                        int *type, const SGMaterial **material, double *agl)
 895 {
 896   SGVec3d _contact, _normal, _vel;
 897   bool ret = ground_cache.get_agl(t, SGVec3d(pt), 2.0, _contact, _normal,
 898                                   _vel, type, material, agl);
 899   sgdCopyVec3(contact, _contact.data());
 900   sgdCopyVec3(normal, _normal.data());
 901   sgdCopyVec3(vel, _vel.data());
 902   return ret;
 903 }
 904
 905 // Legacy interface just kept because of JSBSim
 906 bool
 907 FGInterface::get_agl_ft(double t, const double pt[3],
 908                         double contact[3], double normal[3], double vel[3],
 909                         int *type, double *loadCapacity,
 910                         double *frictionFactor, double *agl)
 911 {
 912   // Convert units and do the real work.
 913   SGVec3d pt_m = SG_FEET_TO_METER*SGVec3d(pt);
 914
 915   const SGMaterial* material;
 916   SGVec3d _contact, _normal, _vel;
 917   bool ret = ground_cache.get_agl(t, pt_m, 2.0, _contact, _normal, _vel,
 918                                   type, &material, agl);
 919   // Convert units back ...
 920   sgdScaleVec3( contact, _contact.data(), SG_METER_TO_FEET );
 921   sgdScaleVec3( vel, _vel.data(), SG_METER_TO_FEET );
 922   sgdCopyVec3( normal, _normal.data() );
 923   *agl *= SG_METER_TO_FEET;
 924
 925   // return material properties if available
 926   if (material) {
 927     // FIXME: convert units?? now pascal to lbf/ft^2
 928     *loadCapacity = 0.020885434*material->get_load_resistance();
 929     *frictionFactor = material->get_friction_factor();
 930   } else {
 931     *loadCapacity = DBL_MAX;
 932     *frictionFactor = 1.0;
 933   }
 934   return ret;
 935 }
 936
 937 bool
 938 FGInterface::get_agl_m(double t, const double pt[3], double max_altoff,
 939                        double contact[3], double normal[3], double vel[3],
 940                        int *type, const SGMaterial** material, double *agl)
 941 {
 942   SGVec3d _contact, _normal, _vel;
 943   bool found = ground_cache.get_agl(t, SGVec3d(pt), max_altoff, _contact,
 944                                     _normal, _vel, type, material, agl);
 945   sgdCopyVec3(contact, _contact.data());
 946   sgdCopyVec3(normal, _normal.data());
 947   sgdCopyVec3(vel, _vel.data());
 948   return found;
 949 }
 950
 951 bool
 952 FGInterface::get_agl_ft(double t, const double pt[3], double max_altoff,
 953                         double contact[3], double normal[3], double vel[3],
 954                         int *type, const SGMaterial** material, double *agl)
 955 {
 956   // Convert units and do the real work.
 957   SGVec3d pt_m = SG_FEET_TO_METER*SGVec3d(pt);
 958   SGVec3d _contact, _normal, _vel;
 959   bool ret = ground_cache.get_agl(t, pt_m, SG_FEET_TO_METER * max_altoff,
 960                                   _contact, _normal, _vel,
 961                                   type, material, agl);
 962   // Convert units back ...
 963   sgdScaleVec3( contact, _contact.data(), SG_METER_TO_FEET );
 964   sgdScaleVec3( vel, _vel.data(), SG_METER_TO_FEET );
 965   sgdCopyVec3( normal, _normal.data() );
 966   *agl *= SG_METER_TO_FEET;
 967   return ret;
 968 }
 969
 970
 971 double
 972 FGInterface::get_groundlevel_m(double lat, double lon, double alt)
 973 {
 974   // Compute the cartesian position of the given lat/lon/alt.
 975   SGVec3d pos = SGVec3d::fromGeod(SGGeod::fromRadM(lon, lat, alt));
 976
 977   // FIXME: how to handle t - ref_time differences ???
 978   SGVec3d cpos;
 979   double ref_time, radius;
 980   // Prepare the ground cache for that position.
 981   if (!is_valid_m(&ref_time, cpos.data(), &radius)) {
 982     bool ok = prepare_ground_cache_m(ref_time, pos.data(), 10);
 983     /// This is most likely the case when the given altitude is
 984     /// too low, try with a new altitude of 10000m, that should be
 985     /// sufficient to find a ground level below everywhere on our planet
 986     if (!ok) {
 987       pos = SGVec3d::fromGeod(SGGeod::fromRadM(lon, lat, 10000));
 988       /// If there is still no ground, return sea level radius
 989       if (!prepare_ground_cache_m(ref_time, pos.data(), 10))
 990         return 0;
 991     }
 992   } else if (radius*radius <= distSqr(pos, cpos)) {
 993     /// We reuse the old radius value, but only if it is at least 10 Meters ..
 994     if (!(10 < radius)) // Well this strange compare is nan safe
 995       radius = 10;
 996
 997     bool ok = prepare_ground_cache_m(ref_time, pos.data(), radius);
 998     /// This is most likely the case when the given altitude is
 999     /// too low, try with a new altitude of 10000m, that should be
1000     /// sufficient to find a ground level below everywhere on our planet
1001     if (!ok) {
1002       pos = SGVec3d::fromGeod(SGGeod::fromRadM(lon, lat, 10000));
1003       /// If there is still no ground, return sea level radius
1004       if (!prepare_ground_cache_m(ref_time, pos.data(), radius))
1005         return 0;
1006     }
1007   }
1008
1009   double contact[3], normal[3], vel[3], agl;
1010   int type;
1011   // Ignore the return value here, since it just tells us if
1012   // the returns stem from the groundcache or from the coarse
1013   // computations below the groundcache. The contact point is still something
1014   // valid, the normals and the other returns just contain some defaults.
1015   get_agl_m(ref_time, pos.data(), 2.0, contact, normal, vel, &type, 0, &agl);
1016   SGGeod geod = SGGeod::fromCart(SGVec3d(contact));
1017   return geod.getElevationM();
1018 }
1019
1020 bool
1021 FGInterface::caught_wire_m(double t, const double pt[4][3])
1022 {
1023   SGVec3d pt_m[4];
1024   for (int i=0; i<4; ++i)
1025     sgdCopyVec3(pt_m[i].data(), pt[i]);
1026
1027   return ground_cache.caught_wire(t, pt_m);
1028 }
1029
1030 bool
1031 FGInterface::caught_wire_ft(double t, const double pt[4][3])
1032 {
1033   // Convert units and do the real work.
1034   SGVec3d pt_m[4];
1035   for (int i=0; i<4; ++i)
1036     sgdScaleVec3(pt_m[i].data(), pt[i], SG_FEET_TO_METER);
1037
1038   return ground_cache.caught_wire(t, pt_m);
1039 }
1040
1041 bool
1042 FGInterface::get_wire_ends_m(double t, double end[2][3], double vel[2][3])
1043 {
1044   SGVec3d _end[2], _vel[2];
1045   bool ret = ground_cache.get_wire_ends(t, _end, _vel);
1046   for (int k=0; k<2; ++k) {
1047     sgdCopyVec3( end[k], _end[k].data() );
1048     sgdCopyVec3( vel[k], _vel[k].data() );
1049   }
1050   return ret;
1051 }
1052
1053 bool
1054 FGInterface::get_wire_ends_ft(double t, double end[2][3], double vel[2][3])
1055 {
1056   // Convert units and do the real work.
1057   SGVec3d _end[2], _vel[2];
1058   bool ret = ground_cache.get_wire_ends(t, _end, _vel);
1059   for (int k=0; k<2; ++k) {
1060     sgdScaleVec3( end[k], _end[k].data(), SG_METER_TO_FEET );
1061     sgdScaleVec3( vel[k], _vel[k].data(), SG_METER_TO_FEET );
1062   }
1063   return ret;
1064 }
1065
1066 void
1067 FGInterface::release_wire(void)
1068 {
1069   ground_cache.release_wire();
1070 }
1071
1072 void fgToggleFDMdataLogging(void) {
1073   cur_fdm_state->ToggleDataLogging();
1074 }