1 // flight.hxx -- define shared flight model parameters
3 // Written by Curtis Olson, started May 1997.
5 // Copyright (C) 1997 Curtis L. Olson - http://www.flightgear.org/~curt
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.
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.
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.
29 # error This library requires C++
35 `FGInterface::get_Longitude ()'
36 `FGInterface::get_Latitude ()'
37 `FGInterface::get_Altitude ()'
38 `FGInterface::get_Phi ()'
39 `FGInterface::get_Theta ()'
40 `FGInterface::get_Psi ()'
41 `FGInterface::get_V_equiv_kts ()'
43 `FGInterface::get_V_north ()'
44 `FGInterface::get_V_east ()'
45 `FGInterface::get_V_down ()'
47 `FGInterface::get_P_Body ()'
48 `FGInterface::get_Q_Body ()'
49 `FGInterface::get_R_Body ()'
51 `FGInterface::get_Gamma_vert_rad ()'
52 `FGInterface::get_Climb_Rate ()'
53 `FGInterface::get_Alpha ()'
54 `FGInterface::get_Beta ()'
56 `FGInterface::get_Runway_altitude ()'
58 `FGInterface::get_Lon_geocentric ()'
59 `FGInterface::get_Lat_geocentric ()'
60 `FGInterface::get_Sea_level_radius ()'
61 `FGInterface::get_Earth_position_angle ()'
63 `FGInterface::get_Latitude_dot()'
64 `FGInterface::get_Longitude_dot()'
65 `FGInterface::get_Radius_dot()'
67 `FGInterface::get_Dx_cg ()'
68 `FGInterface::get_Dy_cg ()'
69 `FGInterface::get_Dz_cg ()'
71 `FGInterface::get_Radius_to_vehicle ()'
82 #include <simgear/compiler.h>
83 #include <simgear/constants.h>
84 #include <simgear/structure/subsystem_mgr.hxx>
85 #include <FDM/groundcache.hxx>
92 * A little helper class to update the track if
93 * the position has changed. In the constructor,
94 * create a copy of the current position and store
95 * references to the position object and the track
97 * The destructor, called at TrackComputer's end of
98 * life/visibility, computes the track if the
99 * position has changed.
101 class TrackComputer {
103 inline TrackComputer( double & track, const SGGeod & position ) :
105 _position( position ),
106 _prevPosition( position ) {
109 inline ~TrackComputer() {
110 if( _prevPosition == _position ) return;
111 _track = SGGeodesy::courseDeg( _prevPosition, _position );
115 const SGGeod & _position;
116 const SGGeod _prevPosition;
119 // This is based heavily on LaRCsim/ls_generic.h
120 class FGInterface : public SGSubsystem {
124 // Has the init() method been called. This is used to delay
125 // initialization until scenery can be loaded and we know the true
129 // Have we bound to the property system
132 // periodic update management variable. This is a scheme to run
133 // the fdm with a fixed delta-t. We control how many iteration of
134 // the fdm to run with the fixed dt based on the elapsed time from
135 // the last update. This allows us to maintain sync with the real
136 // time clock, even though each frame could take a random amount
137 // of time. Since "dt" is unlikely to divide evenly into the
138 // elapse time, we keep track of the remainder and add it into the
139 // next elapsed time. This yields a small amount of temporal
140 // jitter ( < dt ) but in practice seems to work well.
142 // CG position w.r.t. ref. point
143 SGVec3d d_cg_rp_body_v;
146 SGVec3d v_dot_local_v;
147 SGVec3d v_dot_body_v;
149 SGVec3d a_pilot_body_v;
151 SGVec3d omega_dot_body_v;
155 SGVec3d v_local_rel_ground_v; // V rel w.r.t. earth surface
156 SGVec3d v_local_airmass_v; // velocity of airmass (steady winds)
157 SGVec3d v_wind_body_v; // Wind-relative velocities in body axis
159 SGVec3d omega_body_v; // Angular B rates
160 SGVec3d euler_rates_v;
161 SGVec3d geocentric_rates_v; // Geocentric linear velocities
164 SGGeod geodetic_position_v;
165 SGVec3d cartesian_position_v;
166 SGGeoc geocentric_position_v;
167 SGVec3d euler_angles_v;
169 // Normal Load Factor
173 double v_rel_wind, v_true_kts;
174 double v_ground_speed, v_equiv_kts;
175 double v_calibrated_kts;
177 // Miscellaneious Quantities
178 double alpha, beta; // in radians
179 double gamma_vert_rad; // Flight path angles
180 double density, mach_number;
181 double static_pressure, total_pressure;
182 double dynamic_pressure;
183 double static_temperature, total_temperature;
184 double sea_level_radius, earth_position_angle;
185 double runway_altitude;
186 double climb_rate; // in feet per second
190 // the ground cache object itself.
191 FGGroundCache ground_cache;
193 void set_A_X_pilot(double x)
194 { _set_Accels_Pilot_Body(x, a_pilot_body_v[1], a_pilot_body_v[2]); }
196 void set_A_Y_pilot(double y)
197 { _set_Accels_Pilot_Body(a_pilot_body_v[0], y, a_pilot_body_v[2]); }
199 void set_A_Z_pilot(double z)
200 { _set_Accels_Pilot_Body(a_pilot_body_v[0], a_pilot_body_v[1], z); }
204 int _calc_multiloop (double dt);
208 // deliberately not virtual so that
209 // FGInterface constructor will call
214 void _updatePositionM(const SGVec3d& cartPos);
215 void _updatePositionFt(const SGVec3d& cartPos) {
216 _updatePositionM(SG_FEET_TO_METER*cartPos);
218 void _updatePosition(const SGGeod& geod);
219 void _updatePosition(const SGGeoc& geoc);
221 void _updateGeodeticPosition( double lat, double lon, double alt );
222 void _updateGeocentricPosition( double lat_geoc, double lon, double alt );
223 void _update_ground_elev_at_pos( void );
225 inline void _set_CG_Position( double dx, double dy, double dz ) {
226 d_cg_rp_body_v[0] = dx;
227 d_cg_rp_body_v[1] = dy;
228 d_cg_rp_body_v[2] = dz;
230 inline void _set_Accels_Local( double north, double east, double down ) {
231 v_dot_local_v[0] = north;
232 v_dot_local_v[1] = east;
233 v_dot_local_v[2] = down;
235 inline void _set_Accels_Body( double u, double v, double w ) {
240 inline void _set_Accels_CG_Body( double x, double y, double z ) {
245 inline void _set_Accels_Pilot_Body( double x, double y, double z ) {
246 a_pilot_body_v[0] = x;
247 a_pilot_body_v[1] = y;
248 a_pilot_body_v[2] = z;
250 inline void _set_Accels_CG_Body_N( double x, double y, double z ) {
255 void _set_Nlf(double n) { nlf=n; }
256 inline void _set_Velocities_Local( double north, double east, double down ){
257 v_local_v[0] = north;
261 inline void _set_Velocities_Ground(double north, double east, double down) {
262 v_local_rel_ground_v[0] = north;
263 v_local_rel_ground_v[1] = east;
264 v_local_rel_ground_v[2] = down;
266 inline void _set_Velocities_Local_Airmass( double north, double east,
269 v_local_airmass_v[0] = north;
270 v_local_airmass_v[1] = east;
271 v_local_airmass_v[2] = down;
273 inline void _set_Velocities_Wind_Body( double u, double v, double w) {
274 v_wind_body_v[0] = u;
275 v_wind_body_v[1] = v;
276 v_wind_body_v[2] = w;
278 inline void _set_V_rel_wind(double vt) { v_rel_wind = vt; }
279 inline void _set_V_ground_speed( double v) { v_ground_speed = v; }
280 inline void _set_V_equiv_kts( double kts ) { v_equiv_kts = kts; }
281 inline void _set_V_calibrated_kts( double kts ) { v_calibrated_kts = kts; }
282 inline void _set_Omega_Body( double p, double q, double r ) {
287 inline void _set_Euler_Rates( double phi, double theta, double psi ) {
288 euler_rates_v[0] = phi;
289 euler_rates_v[1] = theta;
290 euler_rates_v[2] = psi;
293 void set_Phi_dot_degps(double x)
295 euler_rates_v[0] = x * SG_DEGREES_TO_RADIANS;
298 void set_Theta_dot_degps(double x)
300 euler_rates_v[1] = x * SG_DEGREES_TO_RADIANS;
303 void set_Psi_dot_degps(double x)
305 euler_rates_v[2] = x * SG_DEGREES_TO_RADIANS;
308 inline void _set_Geocentric_Rates( double lat, double lon, double rad ) {
309 geocentric_rates_v[0] = lat;
310 geocentric_rates_v[1] = lon;
311 geocentric_rates_v[2] = rad;
313 inline void _set_Geocentric_Position( double lat, double lon, double rad ) {
314 geocentric_position_v.setLatitudeRad(lat);
315 geocentric_position_v.setLongitudeRad(lon);
316 geocentric_position_v.setRadiusFt(rad);
318 /* Don't call _set_L[at|ong]itude() directly, use _set_Geodetic_Position() instead.
319 These methods can't update the track.
321 inline void _set_Latitude(double lat) {
322 geodetic_position_v.setLatitudeRad(lat);
324 inline void _set_Longitude(double lon) {
325 geodetic_position_v.setLongitudeRad(lon);
328 inline void _set_Altitude(double altitude) {
329 geodetic_position_v.setElevationFt(altitude);
331 inline void _set_Altitude_AGL(double agl) {
334 inline void _set_Geodetic_Position( double lat, double lon ) {
335 _set_Geodetic_Position( lat, lon, geodetic_position_v.getElevationFt());
337 inline void _set_Geodetic_Position( double lat, double lon, double alt ) {
338 TrackComputer tracker( track, geodetic_position_v );
339 geodetic_position_v.setLatitudeRad(lat);
340 geodetic_position_v.setLongitudeRad(lon);
341 geodetic_position_v.setElevationFt(alt);
343 inline void _set_Euler_Angles( double phi, double theta, double psi ) {
344 euler_angles_v[0] = phi;
345 euler_angles_v[1] = theta;
346 euler_angles_v[2] = psi;
348 // FIXME, for compatibility with JSBSim
349 inline void _set_T_Local_to_Body( int i, int j, double value) { }
350 inline void _set_Alpha( double a ) { alpha = a; }
351 inline void _set_Beta( double b ) { beta = b; }
353 inline void set_Alpha_deg( double a ) { alpha = a * SG_DEGREES_TO_RADIANS; }
355 inline void _set_Gamma_vert_rad( double gv ) { gamma_vert_rad = gv; }
356 inline void _set_Density( double d ) { density = d; }
357 inline void _set_Mach_number( double m ) { mach_number = m; }
358 inline void _set_Static_pressure( double sp ) { static_pressure = sp; }
359 inline void _set_Static_temperature( double t ) { static_temperature = t; }
360 inline void _set_Total_temperature( double tat ) { total_temperature = tat; } //JW
361 inline void _set_Sea_level_radius( double r ) { sea_level_radius = r; }
362 inline void _set_Earth_position_angle(double a) { earth_position_angle = a; }
363 inline void _set_Runway_altitude( double alt ) { runway_altitude = alt; }
364 inline void _set_Climb_Rate(double rate) { climb_rate = rate; }
369 FGInterface( double dt );
370 virtual ~FGInterface();
372 virtual void init ();
373 virtual void bind ();
374 virtual void unbind ();
375 virtual void update(double dt);
376 virtual bool ToggleDataLogging(bool state) { return false; }
377 virtual bool ToggleDataLogging(void) { return false; }
379 // Define the various supported flight models (many not yet implemented)
384 // The NASA LaRCsim (Navion) flight model
387 // Jon S. Berndt's new FDM written from the ground up in C++
390 // Christian's hot air balloon simulation
393 // Aeronautical DEvelopment AGEncy, Bangalore India
396 // The following aren't implemented but are here to spark
397 // thoughts and discussions, and maybe even action.
404 // Driven externally via a serial port, net, file, etc.
409 inline bool get_inited() const { return inited; }
410 inline void set_inited( bool value ) { inited = value; }
412 inline bool get_bound() const { return bound; }
414 //perform initializion that is common to all FDM's
418 virtual void set_Latitude(double lat); // geocentric
419 virtual void set_Longitude(double lon);
420 virtual void set_Altitude(double alt); // triggers re-calc of AGL altitude
421 virtual void set_AltitudeAGL(double altagl); // and vice-versa
422 virtual void set_Latitude_deg (double lat) {
423 set_Latitude(lat * SGD_DEGREES_TO_RADIANS);
425 virtual void set_Longitude_deg (double lon) {
426 set_Longitude(lon * SGD_DEGREES_TO_RADIANS);
429 // Speeds -- setting any of these will trigger a re-calc of the rest
430 virtual void set_V_calibrated_kts(double vc);
431 virtual void set_Mach_number(double mach);
432 virtual void set_Velocities_Local( double north, double east, double down );
433 inline void set_V_north (double north) {
434 set_Velocities_Local(north, v_local_v[1], v_local_v[2]);
436 inline void set_V_east (double east) {
437 set_Velocities_Local(v_local_v[0], east, v_local_v[2]);
439 inline void set_V_down (double down) {
440 set_Velocities_Local(v_local_v[0], v_local_v[1], down);
442 virtual void set_Velocities_Wind_Body( double u, double v, double w);
443 virtual void set_uBody (double uBody) {
444 set_Velocities_Wind_Body(uBody, v_wind_body_v[1], v_wind_body_v[2]);
446 virtual void set_vBody (double vBody) {
447 set_Velocities_Wind_Body(v_wind_body_v[0], vBody, v_wind_body_v[2]);
449 virtual void set_wBody (double wBody) {
450 set_Velocities_Wind_Body(v_wind_body_v[0], v_wind_body_v[1], wBody);
454 virtual void set_Euler_Angles( double phi, double theta, double psi );
455 virtual void set_Phi (double phi) {
456 set_Euler_Angles(phi, get_Theta(), get_Psi());
458 virtual void set_Theta (double theta) {
459 set_Euler_Angles(get_Phi(), theta, get_Psi());
461 virtual void set_Psi (double psi) {
462 set_Euler_Angles(get_Phi(), get_Theta(), psi);
464 virtual void set_Phi_deg (double phi) {
465 set_Phi(phi * SGD_DEGREES_TO_RADIANS);
467 virtual void set_Theta_deg (double theta) {
468 set_Theta(theta * SGD_DEGREES_TO_RADIANS);
470 virtual void set_Psi_deg (double psi) {
471 set_Psi(psi * SGD_DEGREES_TO_RADIANS);
475 virtual void set_Climb_Rate( double roc);
476 virtual void set_Gamma_vert_rad( double gamma);
480 virtual void set_Static_pressure(double p);
481 virtual void set_Static_temperature(double T);
482 virtual void set_Density(double rho);
484 virtual void set_Velocities_Local_Airmass (double wnorth,
488 // ========== Mass properties and geometry values ==========
490 // CG position w.r.t. ref. point
491 inline double get_Dx_cg() const { return d_cg_rp_body_v[0]; }
492 inline double get_Dy_cg() const { return d_cg_rp_body_v[1]; }
493 inline double get_Dz_cg() const { return d_cg_rp_body_v[2]; }
495 // ========== Accelerations ==========
497 inline double get_V_dot_north() const { return v_dot_local_v[0]; }
498 inline double get_V_dot_east() const { return v_dot_local_v[1]; }
499 inline double get_V_dot_down() const { return v_dot_local_v[2]; }
501 inline double get_U_dot_body() const { return v_dot_body_v[0]; }
502 inline double get_V_dot_body() const { return v_dot_body_v[1]; }
503 inline double get_W_dot_body() const { return v_dot_body_v[2]; }
505 inline double get_A_X_cg() const { return a_cg_body_v[0]; }
506 inline double get_A_Y_cg() const { return a_cg_body_v[1]; }
507 inline double get_A_Z_cg() const { return a_cg_body_v[2]; }
509 inline double get_A_X_pilot() const { return a_pilot_body_v[0]; }
510 inline double get_A_Y_pilot() const { return a_pilot_body_v[1]; }
511 inline double get_A_Z_pilot() const { return a_pilot_body_v[2]; }
513 inline double get_N_X_cg() const { return n_cg_body_v[0]; }
514 inline double get_N_Y_cg() const { return n_cg_body_v[1]; }
515 inline double get_N_Z_cg() const { return n_cg_body_v[2]; }
517 inline double get_Nlf(void) const { return nlf; }
519 // ========== Velocities ==========
521 inline double get_V_north() const { return v_local_v[0]; }
522 inline double get_V_east() const { return v_local_v[1]; }
523 inline double get_V_down() const { return v_local_v[2]; }
524 inline double get_uBody () const { return v_wind_body_v[0]; }
525 inline double get_vBody () const { return v_wind_body_v[1]; }
526 inline double get_wBody () const { return v_wind_body_v[2]; }
528 // Please dont comment these out. fdm=ada uses these (see
530 inline double get_V_north_rel_ground() const {
531 return v_local_rel_ground_v[0];
533 inline double get_V_east_rel_ground() const {
534 return v_local_rel_ground_v[1];
536 inline double get_V_down_rel_ground() const {
537 return v_local_rel_ground_v[2];
539 // <--- fdm=ada uses these (see cockpit.cxx)
541 inline double get_V_north_airmass() const { return v_local_airmass_v[0]; }
542 inline double get_V_east_airmass() const { return v_local_airmass_v[1]; }
543 inline double get_V_down_airmass() const { return v_local_airmass_v[2]; }
545 inline double get_U_body() const { return v_wind_body_v[0]; }
546 inline double get_V_body() const { return v_wind_body_v[1]; }
547 inline double get_W_body() const { return v_wind_body_v[2]; }
549 inline double get_V_rel_wind() const { return v_rel_wind; }
551 inline double get_V_true_kts() const { return v_true_kts; }
553 inline double get_V_ground_speed() const { return v_ground_speed; }
554 inline double get_V_ground_speed_kt() const { return v_ground_speed * SG_FEET_TO_METER * 3600 * SG_METER_TO_NM; }
555 inline void set_V_ground_speed_kt(double ground_speed) { v_ground_speed = ground_speed / ( SG_FEET_TO_METER * 3600 * SG_METER_TO_NM); }
557 inline double get_V_equiv_kts() const { return v_equiv_kts; }
559 inline double get_V_calibrated_kts() const { return v_calibrated_kts; }
561 inline double get_P_body() const { return omega_body_v[0]; }
562 inline double get_Q_body() const { return omega_body_v[1]; }
563 inline double get_R_body() const { return omega_body_v[2]; }
565 inline double get_Phi_dot() const { return euler_rates_v[0]; }
566 inline double get_Theta_dot() const { return euler_rates_v[1]; }
567 inline double get_Psi_dot() const { return euler_rates_v[2]; }
568 inline double get_Phi_dot_degps() const { return euler_rates_v[0] * SGD_RADIANS_TO_DEGREES; }
569 inline double get_Theta_dot_degps() const { return euler_rates_v[1] * SGD_RADIANS_TO_DEGREES; }
570 inline double get_Psi_dot_degps() const { return euler_rates_v[2] * SGD_RADIANS_TO_DEGREES; }
572 inline double get_Latitude_dot() const { return geocentric_rates_v[0]; }
573 inline double get_Longitude_dot() const { return geocentric_rates_v[1]; }
574 inline double get_Radius_dot() const { return geocentric_rates_v[2]; }
576 // ========== Positions ==========
578 inline double get_Lat_geocentric() const {
579 return geocentric_position_v.getLatitudeRad();
581 inline double get_Lon_geocentric() const {
582 return geocentric_position_v.getLongitudeRad();
584 inline double get_Radius_to_vehicle() const {
585 return geocentric_position_v.getRadiusFt();
588 const SGGeod& getPosition() const { return geodetic_position_v; }
589 const SGGeoc& getGeocPosition() const { return geocentric_position_v; }
590 const SGVec3d& getCartPosition() const { return cartesian_position_v; }
592 inline double get_Latitude() const {
593 return geodetic_position_v.getLatitudeRad();
595 inline double get_Longitude() const {
596 return geodetic_position_v.getLongitudeRad();
598 inline double get_Altitude() const {
599 return geodetic_position_v.getElevationFt();
601 inline double get_Altitude_AGL(void) const { return altitude_agl; }
602 inline double get_Track(void) const { return track; }
604 inline double get_Latitude_deg () const {
605 return geodetic_position_v.getLatitudeDeg();
607 inline double get_Longitude_deg () const {
608 return geodetic_position_v.getLongitudeDeg();
611 inline double get_Phi() const { return euler_angles_v[0]; }
612 inline double get_Theta() const { return euler_angles_v[1]; }
613 inline double get_Psi() const { return euler_angles_v[2]; }
614 inline double get_Phi_deg () const { return get_Phi() * SGD_RADIANS_TO_DEGREES; }
615 inline double get_Theta_deg () const { return get_Theta() * SGD_RADIANS_TO_DEGREES; }
616 inline double get_Psi_deg () const { return get_Psi() * SGD_RADIANS_TO_DEGREES; }
619 // ========== Miscellaneous quantities ==========
621 inline double get_Alpha() const { return alpha; }
622 inline double get_Alpha_deg() const { return alpha * SGD_RADIANS_TO_DEGREES; }
623 inline double get_Beta() const { return beta; }
624 inline double get_Beta_deg() const { return beta * SGD_RADIANS_TO_DEGREES; }
625 inline double get_Gamma_vert_rad() const { return gamma_vert_rad; }
627 inline double get_Density() const { return density; }
628 inline double get_Mach_number() const { return mach_number; }
630 inline double get_Static_pressure() const { return static_pressure; }
631 inline double get_Total_pressure() const { return total_pressure; }
632 inline double get_Dynamic_pressure() const { return dynamic_pressure; }
634 inline double get_Static_temperature() const { return static_temperature; }
635 inline double get_Total_temperature() const { return total_temperature; }
637 inline double get_Sea_level_radius() const { return sea_level_radius; }
638 inline double get_Earth_position_angle() const {
639 return earth_position_angle;
642 inline double get_Runway_altitude() const { return runway_altitude; }
643 inline double get_Runway_altitude_m() const { return SG_FEET_TO_METER * runway_altitude; }
645 inline double get_Climb_Rate() const { return climb_rate; }
647 // Note that currently this is the "same" value runway altitude...
648 inline double get_ground_elev_ft() const { return runway_altitude; }
651 //////////////////////////////////////////////////////////////////////////
652 // Ground handling routines
653 //////////////////////////////////////////////////////////////////////////
655 // Prepare the ground cache for the wgs84 position pt_*.
656 // That is take all vertices in the ball with radius rad around the
657 // position given by the pt_* and store them in a local scene graph.
658 bool prepare_ground_cache_m(double startSimTime, double endSimTime,
659 const double pt[3], double rad);
660 bool prepare_ground_cache_ft(double startSimTime, double endSimTime,
661 const double pt[3], double rad);
664 // Returns true if the cache is valid.
665 // Also the reference time, point and radius values where the cache
666 // is valid for are returned.
667 bool is_valid_m(double *ref_time, double pt[3], double *rad);
668 bool is_valid_ft(double *ref_time, double pt[3], double *rad);
670 // Return the nearest catapult to the given point
671 // pt in wgs84 coordinates.
672 double get_cat_m(double t, const double pt[3],
673 double end[2][3], double vel[2][3]);
674 double get_cat_ft(double t, const double pt[3],
675 double end[2][3], double vel[2][3]);
678 // Return the orientation and position matrix and the linear and angular
679 // velocity of that local coordinate systems origin for a given time and
680 // body id. The velocities are in the wgs84 frame at the bodys origin.
681 bool get_body_m(double t, simgear::BVHNode::Id id, double bodyToWorld[16],
682 double linearVel[3], double angularVel[3]);
685 // Return the altitude above ground below the wgs84 point pt
686 // Search for the nearest triangle to pt in downward direction.
687 // Return ground properties. The velocities are in the wgs84 frame at the
689 bool get_agl_m(double t, const double pt[3], double max_altoff,
690 double contact[3], double normal[3], double linearVel[3],
691 double angularVel[3], SGMaterial const*& material,
692 simgear::BVHNode::Id& id);
693 bool get_agl_ft(double t, const double pt[3], double max_altoff,
694 double contact[3], double normal[3], double linearVel[3],
695 double angularVel[3], SGMaterial const*& material,
696 simgear::BVHNode::Id& id);
697 double get_groundlevel_m(double lat, double lon, double alt);
698 double get_groundlevel_m(const SGGeod& geod);
701 // Return the nearest point in any direction to the point pt with a maximum
702 // distance maxDist. The velocities are in the wgs84 frame at the query
704 bool get_nearest_m(double t, const double pt[3], double maxDist,
705 double contact[3], double normal[3], double linearVel[3],
706 double angularVel[3], SGMaterial const*& material,
707 simgear::BVHNode::Id& id);
708 bool get_nearest_ft(double t, const double pt[3], double maxDist,
709 double contact[3], double normal[3],double linearVel[3],
710 double angularVel[3], SGMaterial const*& material,
711 simgear::BVHNode::Id& id);
714 // Return 1 if the hook intersects with a wire.
715 // That test is done by checking if the quad spanned by the points pt*
716 // intersects with the line representing the wire.
717 // If the wire is caught, the cache will trace this wires endpoints until
718 // the FDM calls release_wire().
719 bool caught_wire_m(double t, const double pt[4][3]);
720 bool caught_wire_ft(double t, const double pt[4][3]);
722 // Return the location and speed of the wire endpoints.
723 bool get_wire_ends_m(double t, double end[2][3], double vel[2][3]);
724 bool get_wire_ends_ft(double t, double end[2][3], double vel[2][3]);
726 // Tell the cache code that it does no longer need to care for
727 // the wire end position.
728 void release_wire(void);
731 #endif // _FLIGHT_HXX