+int
+FGInterface::_calc_multiloop (double dt)
+{
+ int hz = fgGetInt("/sim/model-hz");
+ int speedup = fgGetInt("/sim/speed-up");
+
+ dt += remainder;
+ remainder = 0;
+ double ml = dt * hz;
+ // Avoid roundoff problems by adding the roundoff itself.
+ // ... ok, two times the roundoff to have enough room.
+ int multiloop = int(floor(ml * (1.0 + 2.0*DBL_EPSILON)));
+ remainder = (ml - multiloop) / hz;
+
+ // If we artificially inflate ml above by a tiny amount to get the
+ // closest integer, then subtract the integer from the original
+ // slightly smaller value, we can get a negative remainder.
+ // Logically this should never happen, and we definitely don't want
+ // to carry a negative remainder over to the next iteration, so
+ // never let the remainder go below zero.
+ //
+ // Note: this fixes a problem where we run 1, 3, 1, 3, 1, 3... loops
+ // of the FDM when in fact we want to run 2, 2, 2, 2, 2...
+ if ( remainder < 0 ) { remainder = 0; }
+
+ return (multiloop * speedup);
+}
+
+
+/**
+ * Set default values for the state of the FDM.
+ *
+ * This method is invoked by the constructors.
+ */
+void
+FGInterface::_setup ()
+{
+ inited = false;
+ bound = false;
+
+ d_cg_rp_body_v = SGVec3d::zeros();
+ v_dot_local_v = SGVec3d::zeros();
+ v_dot_body_v = SGVec3d::zeros();
+ a_cg_body_v = SGVec3d::zeros();
+ a_pilot_body_v = SGVec3d::zeros();
+ n_cg_body_v = SGVec3d::zeros();
+ v_local_v = SGVec3d::zeros();
+ v_local_rel_ground_v = SGVec3d::zeros();
+ v_local_airmass_v = SGVec3d::zeros();
+ v_wind_body_v = SGVec3d::zeros();
+ omega_body_v = SGVec3d::zeros();
+ euler_rates_v = SGVec3d::zeros();
+ geocentric_rates_v = SGVec3d::zeros();
+ geodetic_position_v = SGGeod::fromRadM(0, 0, 0);
+ cartesian_position_v = SGVec3d::fromGeod(geodetic_position_v);
+ geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
+ euler_angles_v = SGVec3d::zeros();
+
+ nlf=0;
+ v_rel_wind=v_true_kts=0;
+ v_ground_speed=v_equiv_kts=0;
+ v_calibrated_kts=0;
+ alpha=beta=0;
+ gamma_vert_rad=0;
+ density=mach_number=0;
+ static_pressure=total_pressure=0;
+ dynamic_pressure=0;
+ static_temperature=total_temperature=0;
+ sea_level_radius=earth_position_angle=0;
+ runway_altitude=0;
+ climb_rate=0;
+ altitude_agl=0;
+}
+
+void
+FGInterface::init () {}
+
+/**
+ * Initialize the state of the FDM.
+ *
+ * Subclasses of FGInterface may do their own, additional initialization,
+ * but there is some that is common to all. Normally, they should call
+ * this before they begin their own init to make sure the basic structures
+ * are set up properly.
+ */
+void
+FGInterface::common_init ()
+{
+ SG_LOG( SG_FLIGHT, SG_INFO, "Start common FDM init" );
+
+ set_inited( true );
+
+ ground_cache.set_cache_time_offset(globals->get_sim_time_sec());
+
+// stamp();
+// set_remainder( 0 );
+
+ // Set initial position
+ SG_LOG( SG_FLIGHT, SG_INFO, "...initializing position..." );
+ double lon = fgGetDouble("/sim/presets/longitude-deg")
+ * SGD_DEGREES_TO_RADIANS;
+ double lat = fgGetDouble("/sim/presets/latitude-deg")
+ * SGD_DEGREES_TO_RADIANS;
+ double alt_ft = fgGetDouble("/sim/presets/altitude-ft");
+ double alt_m = alt_ft * SG_FEET_TO_METER;
+ set_Longitude( lon );
+ set_Latitude( lat );
+ SG_LOG( SG_FLIGHT, SG_INFO, "Checking for lon = "
+ << lon*SGD_RADIANS_TO_DEGREES << "deg, lat = "
+ << lat*SGD_RADIANS_TO_DEGREES << "deg, alt = "
+ << alt_ft << "ft");
+
+ double ground_elev_m = get_groundlevel_m(lat, lon, alt_m);
+ double ground_elev_ft = ground_elev_m * SG_METER_TO_FEET;
+ _set_Runway_altitude ( ground_elev_ft );
+ if ( fgGetBool("/sim/presets/onground") || alt_ft < ground_elev_ft ) {
+ fgSetDouble("/position/altitude-ft", ground_elev_ft + 0.1);
+ set_Altitude( ground_elev_ft + 0.1);
+ } else {
+ set_Altitude( alt_ft );
+ }
+
+ // Set ground elevation
+ SG_LOG( SG_FLIGHT, SG_INFO,
+ "...initializing ground elevation to " << ground_elev_ft
+ << "ft..." );
+
+ // Set sea-level radius
+ SG_LOG( SG_FLIGHT, SG_INFO, "...initializing sea-level radius..." );
+ SG_LOG( SG_FLIGHT, SG_INFO, " lat = "
+ << fgGetDouble("/sim/presets/latitude-deg")
+ << " alt = " << get_Altitude() );
+ double slr = SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v);
+ _set_Sea_level_radius( slr * SG_METER_TO_FEET );
+
+ // Set initial velocities
+ SG_LOG( SG_FLIGHT, SG_INFO, "...initializing velocities..." );
+ if ( !fgHasNode("/sim/presets/speed-set") ) {
+ set_V_calibrated_kts(0.0);
+ } else {
+ const string speedset = fgGetString("/sim/presets/speed-set");
+ if ( speedset == "knots" || speedset == "KNOTS" ) {
+ set_V_calibrated_kts( fgGetDouble("/sim/presets/airspeed-kt") );
+ } else if ( speedset == "mach" || speedset == "MACH" ) {
+ set_Mach_number( fgGetDouble("/sim/presets/mach") );
+ } else if ( speedset == "UVW" || speedset == "uvw" ) {
+ set_Velocities_Wind_Body(
+ fgGetDouble("/sim/presets/uBody-fps"),
+ fgGetDouble("/sim/presets/vBody-fps"),
+ fgGetDouble("/sim/presets/wBody-fps") );
+ } else if ( speedset == "NED" || speedset == "ned" ) {
+ set_Velocities_Local(
+ fgGetDouble("/sim/presets/speed-north-fps"),
+ fgGetDouble("/sim/presets/speed-east-fps"),
+ fgGetDouble("/sim/presets/speed-down-fps") );
+ } else {
+ SG_LOG( SG_FLIGHT, SG_ALERT,
+ "Unrecognized value for /sim/presets/speed-set: "
+ << speedset);
+ set_V_calibrated_kts( 0.0 );
+ }
+ }
+
+ // Set initial Euler angles
+ SG_LOG( SG_FLIGHT, SG_INFO, "...initializing Euler angles..." );
+ set_Euler_Angles( fgGetDouble("/sim/presets/roll-deg")
+ * SGD_DEGREES_TO_RADIANS,
+ fgGetDouble("/sim/presets/pitch-deg")
+ * SGD_DEGREES_TO_RADIANS,
+ fgGetDouble("/sim/presets/heading-deg")
+ * SGD_DEGREES_TO_RADIANS );
+
+ SG_LOG( SG_FLIGHT, SG_INFO, "End common FDM init" );
+}
+
+
+/**
+ * Bind getters and setters to properties.
+ *
+ * The bind() method will be invoked after init(). Note that unlike
+ * the usual implementations of FGSubsystem::bind(), this method does
+ * not automatically pick up existing values for the properties at
+ * bind time; instead, all values are set explicitly in the init()
+ * method.
+ */
+void
+FGInterface::bind ()
+{
+ bound = true;
+
+ // Time management (read-only)
+// fgTie("/fdm/time/delta_t", this,
+// &FGInterface::get_delta_t); // read-only
+// fgTie("/fdm/time/elapsed", this,
+// &FGInterface::get_elapsed); // read-only
+// fgTie("/fdm/time/remainder", this,
+// &FGInterface::get_remainder); // read-only
+// fgTie("/fdm/time/multi_loop", this,
+// &FGInterface::get_multi_loop); // read-only
+
+ // Aircraft position
+ fgTie("/position/latitude-deg", this,
+ &FGInterface::get_Latitude_deg,
+ &FGInterface::set_Latitude_deg,
+ false);
+ fgSetArchivable("/position/latitude-deg");
+ fgTie("/position/longitude-deg", this,
+ &FGInterface::get_Longitude_deg,
+ &FGInterface::set_Longitude_deg,
+ false);
+ fgSetArchivable("/position/longitude-deg");
+ fgTie("/position/altitude-ft", this,
+ &FGInterface::get_Altitude,
+ &FGInterface::set_Altitude,
+ false);
+ fgSetArchivable("/position/altitude-ft");
+ fgTie("/position/altitude-agl-ft", this,
+ &FGInterface::get_Altitude_AGL); // read-only
+ fgSetArchivable("/position/ground-elev-ft");
+ fgTie("/position/ground-elev-ft", this,
+ &FGInterface::get_Runway_altitude); // read-only
+ fgSetArchivable("/position/ground-elev-m");
+ fgTie("/position/ground-elev-m", this,
+ &FGInterface::get_Runway_altitude_m); // read-only
+ fgTie("/environment/ground-elevation-m", this,
+ &FGInterface::get_Runway_altitude_m); // read-only
+ fgSetArchivable("/position/sea-level-radius-ft");
+ fgTie("/position/sea-level-radius-ft", this,
+ &FGInterface::get_Sea_level_radius); // read-only
+
+ // Orientation
+ fgTie("/orientation/roll-deg", this,
+ &FGInterface::get_Phi_deg,
+ &FGInterface::set_Phi_deg);
+ fgSetArchivable("/orientation/roll-deg");
+ fgTie("/orientation/pitch-deg", this,
+ &FGInterface::get_Theta_deg,
+ &FGInterface::set_Theta_deg);
+ fgSetArchivable("/orientation/pitch-deg");
+ fgTie("/orientation/heading-deg", this,
+ &FGInterface::get_Psi_deg,
+ &FGInterface::set_Psi_deg);
+ fgSetArchivable("/orientation/heading-deg");
+
+ // Body-axis "euler rates" (rotation speed, but in a funny
+ // representation).
+ fgTie("/orientation/roll-rate-degps", this,
+ &FGInterface::get_Phi_dot_degps);
+ fgTie("/orientation/pitch-rate-degps", this,
+ &FGInterface::get_Theta_dot_degps);
+ fgTie("/orientation/yaw-rate-degps", this,
+ &FGInterface::get_Psi_dot_degps);
+
+ // Ground speed knots
+ fgTie("/velocities/groundspeed-kt", this,
+ &FGInterface::get_V_ground_speed_kt);
+
+ // Calibrated airspeed
+ fgTie("/velocities/airspeed-kt", this,
+ &FGInterface::get_V_calibrated_kts,
+ &FGInterface::set_V_calibrated_kts,
+ false);
+
+ // Mach number
+ fgTie("/velocities/mach", this,
+ &FGInterface::get_Mach_number,
+ &FGInterface::set_Mach_number,
+ false);
+
+ // Local velocities
+// fgTie("/velocities/speed-north-fps", this,
+// &FGInterface::get_V_north,
+// &FGInterface::set_V_north);
+// fgSetArchivable("/velocities/speed-north-fps");
+// fgTie("/velocities/speed-east-fps", this,
+// &FGInterface::get_V_east,
+// &FGInterface::set_V_east);
+// fgSetArchivable("/velocities/speed-east-fps");
+// fgTie("/velocities/speed-down-fps", this,
+// &FGInterface::get_V_down,
+// &FGInterface::set_V_down);
+// fgSetArchivable("/velocities/speed-down-fps");
+ // FIXME: Temporarily read-only, until the
+ // incompatibilities between JSBSim and
+ // LaRCSim are fixed (LaRCSim adds the
+ // earth's rotation to the east velocity).
+ fgTie("/velocities/speed-north-fps", this,
+ &FGInterface::get_V_north);
+ fgTie("/velocities/speed-east-fps", this,
+ &FGInterface::get_V_east);
+ fgTie("/velocities/speed-down-fps", this,
+ &FGInterface::get_V_down);
+
+ // Relative wind
+ // FIXME: temporarily archivable, until
+ // the NED problem is fixed.
+ fgTie("/velocities/uBody-fps", this,
+ &FGInterface::get_uBody,
+ &FGInterface::set_uBody,
+ false);
+ fgSetArchivable("/velocities/uBody-fps");
+ fgTie("/velocities/vBody-fps", this,
+ &FGInterface::get_vBody,
+ &FGInterface::set_vBody,
+ false);
+ fgSetArchivable("/velocities/vBody-fps");
+ fgTie("/velocities/wBody-fps", this,
+ &FGInterface::get_wBody,
+ &FGInterface::set_wBody,
+ false);
+ fgSetArchivable("/velocities/wBody-fps");
+
+ // Climb and slip (read-only)
+ fgTie("/velocities/vertical-speed-fps", this,
+ &FGInterface::get_Climb_Rate,
+ &FGInterface::set_Climb_Rate );
+ fgTie("/velocities/glideslope", this,
+ &FGInterface::get_Gamma_vert_rad,
+ &FGInterface::set_Gamma_vert_rad );
+ fgTie("/orientation/side-slip-rad", this,
+ &FGInterface::get_Beta); // read-only
+ fgTie("/orientation/side-slip-deg", this,
+ &FGInterface::get_Beta_deg); // read-only
+ fgTie("/orientation/alpha-deg", this,
+ &FGInterface::get_Alpha_deg); // read-only
+ fgTie("/accelerations/nlf", this,
+ &FGInterface::get_Nlf); // read-only
+
+ // NED accelerations
+ fgTie("/accelerations/ned/north-accel-fps_sec",
+ this, &FGInterface::get_V_dot_north);
+ fgTie("/accelerations/ned/east-accel-fps_sec",
+ this, &FGInterface::get_V_dot_east);
+ fgTie("/accelerations/ned/down-accel-fps_sec",
+ this, &FGInterface::get_V_dot_down);
+
+ // Pilot accelerations
+ fgTie("/accelerations/pilot/x-accel-fps_sec",
+ this, &FGInterface::get_A_X_pilot);
+ fgTie("/accelerations/pilot/y-accel-fps_sec",
+ this, &FGInterface::get_A_Y_pilot);
+ fgTie("/accelerations/pilot/z-accel-fps_sec",
+ this, &FGInterface::get_A_Z_pilot);
+
+}
+
+
+/**
+ * Unbind any properties bound to this FDM.
+ *
+ * This method allows the FDM to release properties so that a new
+ * FDM can bind them instead.
+ */
+void
+FGInterface::unbind ()
+{
+ bound = false;
+
+ // fgUntie("/fdm/time/delta_t");
+ // fgUntie("/fdm/time/elapsed");
+ // fgUntie("/fdm/time/remainder");
+ // fgUntie("/fdm/time/multi_loop");
+ fgUntie("/position/latitude-deg");
+ fgUntie("/position/longitude-deg");
+ fgUntie("/position/altitude-ft");
+ fgUntie("/position/altitude-agl-ft");
+ fgUntie("/position/ground-elev-ft");
+ fgUntie("/position/ground-elev-m");
+ fgUntie("/environment/ground-elevation-m");
+ fgUntie("/position/sea-level-radius-ft");
+ fgUntie("/orientation/roll-deg");
+ fgUntie("/orientation/pitch-deg");
+ fgUntie("/orientation/heading-deg");
+ fgUntie("/orientation/roll-rate-degps");
+ fgUntie("/orientation/pitch-rate-degps");
+ fgUntie("/orientation/yaw-rate-degps");
+ fgUntie("/orientation/side-slip-rad");
+ fgUntie("/orientation/side-slip-deg");
+ fgUntie("/orientation/alpha-deg");
+ fgUntie("/velocities/airspeed-kt");
+ fgUntie("/velocities/groundspeed-kt");
+ fgUntie("/velocities/mach");
+ fgUntie("/velocities/speed-north-fps");
+ fgUntie("/velocities/speed-east-fps");
+ fgUntie("/velocities/speed-down-fps");
+ fgUntie("/velocities/uBody-fps");
+ fgUntie("/velocities/vBody-fps");
+ fgUntie("/velocities/wBody-fps");
+ fgUntie("/velocities/vertical-speed-fps");
+ fgUntie("/velocities/glideslope");
+ fgUntie("/accelerations/nlf");
+ fgUntie("/accelerations/pilot/x-accel-fps_sec");
+ fgUntie("/accelerations/pilot/y-accel-fps_sec");
+ fgUntie("/accelerations/pilot/z-accel-fps_sec");
+ fgUntie("/accelerations/ned/north-accel-fps_sec");
+ fgUntie("/accelerations/ned/east-accel-fps_sec");
+ fgUntie("/accelerations/ned/down-accel-fps_sec");
+}
+
+/**
+ * Update the state of the FDM (i.e. run the equations of motion).
+ */
+void
+FGInterface::update (double dt)
+{
+ SG_LOG(SG_FLIGHT, SG_ALERT, "dummy update() ... SHOULDN'T BE CALLED!");
+}
+
+
+void FGInterface::_updatePositionM(const SGVec3d& cartPos)
+{
+ cartesian_position_v = cartPos;
+ geodetic_position_v = SGGeod::fromCart(cartesian_position_v);
+ geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
+ _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
+ _update_ground_elev_at_pos();
+}
+
+
+void FGInterface::_updatePosition(const SGGeod& geod)
+{
+ geodetic_position_v = geod;
+ cartesian_position_v = SGVec3d::fromGeod(geodetic_position_v);
+ geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
+
+ _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
+ _update_ground_elev_at_pos();
+}
+
+
+void FGInterface::_updatePosition(const SGGeoc& geoc)
+{
+ geocentric_position_v = geoc;
+ cartesian_position_v = SGVec3d::fromGeoc(geocentric_position_v);
+ geodetic_position_v = SGGeod::fromCart(cartesian_position_v);
+
+ _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
+ _update_ground_elev_at_pos();
+}
+