1 // FGAIBase - abstract base class for AI objects
2 // Written by David Culp, started Nov 2003, based on
3 // David Luff's FGAIEntity class.
4 // - davidculp2@comcast.net
6 // With additions by Mathias Froehlich & Vivian Meazza 2004 -2007
8 // This program is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU General Public License as
10 // published by the Free Software Foundation; either version 2 of the
11 // License, or (at your option) any later version.
13 // This program is distributed in the hope that it will be useful, but
14 // WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
29 #include <simgear/compiler.h>
31 #include <boost/foreach.hpp>
34 #include <osg/ref_ptr>
36 #include <osgDB/FileUtils>
38 #include <simgear/misc/sg_path.hxx>
39 #include <simgear/scene/model/modellib.hxx>
40 #include <simgear/scene/util/SGNodeMasks.hxx>
41 #include <simgear/debug/logstream.hxx>
42 #include <simgear/props/props.hxx>
44 #include <Main/globals.hxx>
45 #include <Main/fg_props.hxx>
46 #include <Scenery/scenery.hxx>
47 #include <Scripting/NasalSys.hxx>
48 #include <Scripting/NasalModelData.hxx>
49 #include <Sound/fg_fx.hxx>
51 #include "AIFlightPlan.hxx"
53 #include "AIManager.hxx"
55 const char *default_model = "Models/Geometry/glider.ac";
56 const double FGAIBase::e = 2.71828183;
57 const double FGAIBase::lbs_to_slugs = 0.031080950172; //conversion factor
60 using namespace simgear;
62 class FGAIModelData : public simgear::SGModelData {
64 FGAIModelData(SGPropertyNode *root = NULL)
65 : _nasal( new FGNasalModelDataProxy(root) ),
68 _hasInteriorPath(false),
69 _interiorLoaded(false)
78 virtual FGAIModelData* clone() const { return new FGAIModelData(); }
80 /** osg callback, thread-safe */
81 void modelLoaded(const std::string& path, SGPropertyNode *prop, osg::Node *n)
83 // WARNING: Called in a separate OSG thread! Only use thread-safe stuff here...
87 if(prop->hasChild("interior-path")){
88 _interiorPath = prop->getStringValue("interior-path");
89 _hasInteriorPath = true;
92 _fxpath = prop->getStringValue("sound/path");
93 _nasal->modelLoaded(path, prop, n);
99 /** init hook to be called after model is loaded.
100 * Not thread-safe. Call from main thread only. */
101 void init(void) { _initialized = true; }
103 bool needInitilization(void) { return _ready && !_initialized;}
104 bool isInitialized(void) { return _initialized;}
105 inline std::string& get_sound_path() { return _fxpath;}
107 void setInteriorLoaded(const bool state) { _interiorLoaded = state;}
108 bool getInteriorLoaded(void) { return _interiorLoaded;}
109 bool hasInteriorPath(void) { return _hasInteriorPath;}
110 inline std::string& getInteriorPath() { return _interiorPath; }
112 std::auto_ptr<FGNasalModelDataProxy> _nasal;
117 std::string _interiorPath;
118 bool _hasInteriorPath;
119 bool _interiorLoaded;
122 FGAIBase::FGAIBase(object_type ot, bool enableHot) :
127 model_removed( fgGetNode("/ai/models/model-removed", true) ),
138 _refID( _newAIModelID() ),
144 tgt_heading = hdg = tgt_altitude_ft = tgt_speed = 0.0;
145 tgt_roll = roll = tgt_pitch = tgt_yaw = tgt_vs = vs = pitch = 0.0;
146 bearing = elevation = range = rdot = 0.0;
147 x_shift = y_shift = rotation = 0.0;
153 _impact_reported = false;
154 _collision_reported = false;
155 _expiry_reported = false;
167 pos = SGGeod::fromDeg(0, 0);
170 speed_north_deg_sec = 0;
171 speed_east_deg_sec = 0;
191 // explicitly disable HOT for (most) AI models
193 aip.getSceneGraph()->setNodeMask(~SG_NODEMASK_TERRAIN_BIT);
196 FGAIBase::~FGAIBase() {
197 // Unregister that one at the scenery manager
201 SGPropertyNode* parent = props->getParent();
204 model_removed->setStringValue(props->getPath());
214 /** Cleanly remove the model
215 * and let the scenery database pager do the clean-up work.
218 FGAIBase::removeModel()
223 FGScenery* pSceneryManager = globals->get_scenery();
224 if (pSceneryManager && pSceneryManager->get_models_branch())
226 osg::ref_ptr<osg::Object> temp = _model.get();
227 pSceneryManager->get_models_branch()->removeChild(aip.getSceneGraph());
228 // withdraw from SGModelPlacement and drop own reference (unref)
233 // pass it on to the pager, to be be deleted in the pager thread
234 pSceneryManager->getPager()->queueDeleteRequest(temp);
244 void FGAIBase::readFromScenario(SGPropertyNode* scFileNode)
249 setPath(scFileNode->getStringValue("model",
250 fgGetString("/sim/multiplay/default-model", default_model)));
252 setHeading(scFileNode->getDoubleValue("heading", 0.0));
253 setSpeed(scFileNode->getDoubleValue("speed", 0.0));
254 setAltitude(scFileNode->getDoubleValue("altitude", 0.0));
255 setLongitude(scFileNode->getDoubleValue("longitude", 0.0));
256 setLatitude(scFileNode->getDoubleValue("latitude", 0.0));
257 setBank(scFileNode->getDoubleValue("roll", 0.0));
259 SGPropertyNode* submodels = scFileNode->getChild("submodels");
262 setServiceable(submodels->getBoolValue("serviceable", false));
263 setSMPath(submodels->getStringValue("path", ""));
268 void FGAIBase::update(double dt) {
270 if (_otype == otStatic)
273 if (_otype == otBallistic)
276 ft_per_deg_lat = 366468.96 - 3717.12 * cos(pos.getLatitudeRad());
277 ft_per_deg_lon = 365228.16 * cos(pos.getLatitudeRad());
281 // update model's audio sample values
282 _fx->set_position_geod( pos );
284 SGQuatd orient = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
285 _fx->set_orientation( orient );
288 velocity = SGVec3d( speed_north_deg_sec, speed_east_deg_sec,
290 _fx->set_velocity( velocity );
292 else if ((_modeldata)&&(_modeldata->needInitilization()))
294 // process deferred nasal initialization,
295 // which must be done in main thread
298 // sound initialization
299 if (fgGetBool("/sim/sound/aimodels/enabled",false))
301 const string& fxpath = _modeldata->get_sound_path();
304 props->setStringValue("sim/sound/path", fxpath.c_str());
306 // initialize the sound configuration
307 std::stringstream name;
310 _fx = new FGFX(name.str(), props);
319 void FGAIBase::updateInterior()
321 if(!_modeldata || !_modeldata->hasInteriorPath())
324 if(!_modeldata->getInteriorLoaded()){ // interior is not yet load
325 double d2 = dist(SGVec3d::fromGeod(pos), globals->get_aircraft_position_cart());
326 if(d2 <= _maxRangeInterior){ // if the AI is in-range we load the interior
327 _interior = SGModelLib::loadPagedModel(_modeldata->getInteriorPath(), props, _modeldata);
328 if(_interior.valid()){
329 _interior->setRange(0, 0.0, _maxRangeInterior);
330 aip.add(_interior.get());
331 _modeldata->setInteriorLoaded(true);
332 SG_LOG(SG_AI, SG_INFO, "AIBase: Loaded interior model " << _interior->getName());
338 /** update LOD properties of the model */
339 void FGAIBase::updateLOD()
341 double maxRangeDetail = fgGetDouble("/sim/rendering/static-lod/ai-detailed", 10000.0);
342 // double maxRangeBare = fgGetDouble("/sim/rendering/static-lod/ai-bare", 20000.0);
344 _maxRangeInterior = fgGetDouble("/sim/rendering/static-lod/ai-interior", 50.0);
347 if( maxRangeDetail == 0.0 )
350 _model->setRange(0, 0.0, FLT_MAX);
351 _model->setRange(1, FLT_MAX, FLT_MAX);
355 if( fgGetBool("/sim/rendering/static-lod/ai-range-mode-pixel", false ) )
357 _model->setRangeMode( osg::LOD::PIXEL_SIZE_ON_SCREEN );
358 _model->setRange(0, maxRangeDetail, 100000 );
360 _model->setRangeMode( osg::LOD:: DISTANCE_FROM_EYE_POINT);
361 _model->setRange(0, 0.0, maxRangeDetail);
367 void FGAIBase::Transform() {
370 aip.setVisible(true);
371 aip.setPosition(pos);
374 aip.setOrientation(0.0, pitch, hdg);
376 aip.setOrientation(roll, pitch, hdg);
380 aip.setVisible(false);
386 bool FGAIBase::init(bool search_in_AI_path)
390 SG_LOG(SG_AI, SG_ALERT, "AIBase: Cannot initialize a model multiple times! " << model_path);
395 if(search_in_AI_path)
397 BOOST_FOREACH(SGPath p, globals->get_data_paths("AI")) {
398 p.append(model_path);
403 } // of AI data paths iteration
404 } // of search in AI path
407 f = simgear::SGModelLib::findDataFile(model_path);
411 f = fgGetString("/sim/multiplay/default-model", default_model);
415 props->addChild("type")->setStringValue("AI");
416 _modeldata = new FGAIModelData(props);
417 _model= SGModelLib::loadPagedModel(f, props, _modeldata);
419 _model->setName("AI-model range animation node");
421 // _model->setCenterMode(osg::LOD::USE_BOUNDING_SPHERE_CENTER);
422 // _model->setRangeMode(osg::LOD::DISTANCE_FROM_EYE_POINT);
424 // We really need low-resolution versions of AI/MP aircraft.
425 // Or at least dummy "stubs" with some default silhouette.
426 // _model->addChild( SGModelLib::loadPagedModel(fgGetString("/sim/multiplay/default-model", default_model),
427 // props, new FGNasalModelData(props)), FLT_MAX, FLT_MAX);
431 if (_model.valid() && _initialized == false) {
432 aip.init( _model.get() );
433 aip.setVisible(true);
435 globals->get_scenery()->get_models_branch()->addChild(aip.getSceneGraph());
438 SG_LOG(SG_AI, SG_DEBUG, "AIBase: Loaded model " << model_path);
440 } else if (!model_path.empty()) {
441 SG_LOG(SG_AI, SG_WARN, "AIBase: Could not load model " << model_path);
442 // not properly installed...
450 void FGAIBase::initModel()
452 if (_model.valid()) {
455 props->setStringValue("submodels/path", _path.c_str());
456 SG_LOG(SG_AI, SG_DEBUG, "AIBase: submodels/path " << _path);
460 props->setStringValue("parent-name", _parent.c_str());
463 fgSetString("/ai/models/model-added", props->getPath().c_str());
464 } else if (!model_path.empty()) {
465 SG_LOG(SG_AI, SG_WARN, "AIBase: Could not load model " << model_path);
472 bool FGAIBase::isa( object_type otype ) {
473 return otype == _otype;
477 void FGAIBase::bind() {
478 _tiedProperties.setRoot(props);
479 tie("id", SGRawValueMethods<FGAIBase,int>(*this,
481 tie("velocities/true-airspeed-kt", SGRawValuePointer<double>(&speed));
482 tie("velocities/vertical-speed-fps",
483 SGRawValueMethods<FGAIBase,double>(*this,
484 &FGAIBase::_getVS_fps,
485 &FGAIBase::_setVS_fps));
487 tie("position/altitude-ft",
488 SGRawValueMethods<FGAIBase,double>(*this,
489 &FGAIBase::_getAltitude,
490 &FGAIBase::_setAltitude));
491 tie("position/latitude-deg",
492 SGRawValueMethods<FGAIBase,double>(*this,
493 &FGAIBase::_getLatitude,
494 &FGAIBase::_setLatitude));
495 tie("position/longitude-deg",
496 SGRawValueMethods<FGAIBase,double>(*this,
497 &FGAIBase::_getLongitude,
498 &FGAIBase::_setLongitude));
500 tie("position/global-x",
501 SGRawValueMethods<FGAIBase,double>(*this,
502 &FGAIBase::_getCartPosX,
504 tie("position/global-y",
505 SGRawValueMethods<FGAIBase,double>(*this,
506 &FGAIBase::_getCartPosY,
508 tie("position/global-z",
509 SGRawValueMethods<FGAIBase,double>(*this,
510 &FGAIBase::_getCartPosZ,
513 SGRawValueMethods<FGAIBase,const char*>(*this,
514 &FGAIBase::_getCallsign,
517 tie("orientation/pitch-deg", SGRawValuePointer<double>(&pitch));
518 tie("orientation/roll-deg", SGRawValuePointer<double>(&roll));
519 tie("orientation/true-heading-deg", SGRawValuePointer<double>(&hdg));
521 tie("radar/in-range", SGRawValuePointer<bool>(&in_range));
522 tie("radar/bearing-deg", SGRawValuePointer<double>(&bearing));
523 tie("radar/elevation-deg", SGRawValuePointer<double>(&elevation));
524 tie("radar/range-nm", SGRawValuePointer<double>(&range));
525 tie("radar/h-offset", SGRawValuePointer<double>(&horiz_offset));
526 tie("radar/v-offset", SGRawValuePointer<double>(&vert_offset));
527 tie("radar/x-shift", SGRawValuePointer<double>(&x_shift));
528 tie("radar/y-shift", SGRawValuePointer<double>(&y_shift));
529 tie("radar/rotation", SGRawValuePointer<double>(&rotation));
530 tie("radar/ht-diff-ft", SGRawValuePointer<double>(&ht_diff));
531 tie("subID", SGRawValuePointer<int>(&_subID));
532 tie("controls/lighting/nav-lights", SGRawValueFunctions<bool>(_isNight));
534 props->setBoolValue("controls/lighting/beacon", true);
535 props->setBoolValue("controls/lighting/strobe", true);
536 props->setBoolValue("controls/glide-path", true);
538 props->setStringValue("controls/flight/lateral-mode", "roll");
539 props->setDoubleValue("controls/flight/target-hdg", hdg);
540 props->setDoubleValue("controls/flight/target-roll", roll);
542 props->setStringValue("controls/flight/longitude-mode", "alt");
543 props->setDoubleValue("controls/flight/target-alt", altitude_ft);
544 props->setDoubleValue("controls/flight/target-pitch", pitch);
546 props->setDoubleValue("controls/flight/target-spd", speed);
548 props->setBoolValue("sim/sound/avionics/enabled", false);
549 props->setDoubleValue("sim/sound/avionics/volume", 0.0);
550 props->setBoolValue("sim/sound/avionics/external-view", false);
551 props->setBoolValue("sim/current-view/internal", false);
554 void FGAIBase::unbind() {
555 _tiedProperties.Untie();
557 props->setBoolValue("/sim/controls/radar", true);
562 void FGAIBase::removeSoundFx() {
563 // drop reference to sound effects now
566 // must remove explicitly - since the sound manager also keeps a reference
568 // now drop last reference - kill the object
573 double FGAIBase::UpdateRadar(FGAIManager* manager)
575 bool control = fgGetBool("/sim/controls/radar", true);
577 if(!control) return 0;
579 double radar_range_m = fgGetDouble("/instrumentation/radar/range");
580 bool force_on = fgGetBool("/instrumentation/radar/debug-mode", false);
581 radar_range_m *= SG_NM_TO_METER * 1.1; // + 10%
582 radar_range_m *= radar_range_m; // squared
584 double d2 = distSqr(SGVec3d::fromGeod(pos), globals->get_aircraft_position_cart());
585 double range_ft = sqrt(d2) * SG_METER_TO_FEET;
587 if (!force_on && (d2 > radar_range_m)) {
588 return range_ft * range_ft;
591 props->setBoolValue("radar/in-range", true);
593 // copy values from the AIManager
594 double user_heading = manager->get_user_heading();
595 double user_pitch = manager->get_user_pitch();
597 range = range_ft * SG_FEET_TO_METER * SG_METER_TO_NM;
599 // calculate bearing to target
600 bearing = SGGeodesy::courseDeg(globals->get_aircraft_position(), pos);
602 // calculate look left/right to target, without yaw correction
603 horiz_offset = bearing - user_heading;
604 SG_NORMALIZE_RANGE(horiz_offset, -180.0, 180.0);
606 // calculate elevation to target
607 ht_diff = altitude_ft - globals->get_aircraft_position().getElevationFt();
608 elevation = atan2( ht_diff, range_ft ) * SG_RADIANS_TO_DEGREES;
610 // calculate look up/down to target
611 vert_offset = elevation - user_pitch;
613 /* this calculation needs to be fixed, but it isn't important anyway
614 // calculate range rate
615 double recip_bearing = bearing + 180.0;
616 if (recip_bearing > 360.0) recip_bearing -= 360.0;
617 double my_horiz_offset = recip_bearing - hdg;
618 if (my_horiz_offset > 180.0) my_horiz_offset -= 360.0;
619 if (my_horiz_offset < -180.0) my_horiz_offset += 360.0;
620 rdot = (-user_speed * cos( horiz_offset * SG_DEGREES_TO_RADIANS ))
621 +(-speed * 1.686 * cos( my_horiz_offset * SG_DEGREES_TO_RADIANS ));
624 // now correct look left/right for yaw
625 // horiz_offset += user_yaw; // FIXME: WHY WOULD WE WANT TO ADD IN SIDE-SLIP HERE?
627 // calculate values for radar display
628 y_shift = range * cos( horiz_offset * SG_DEGREES_TO_RADIANS);
629 x_shift = range * sin( horiz_offset * SG_DEGREES_TO_RADIANS);
631 rotation = hdg - user_heading;
632 SG_NORMALIZE_RANGE(rotation, 0.0, 360.0);
634 return range_ft * range_ft;
638 * Getters and Setters
641 SGVec3d FGAIBase::getCartPosAt(const SGVec3d& _off) const {
642 // Transform that one to the horizontal local coordinate system.
643 SGQuatd hlTrans = SGQuatd::fromLonLat(pos);
645 // and postrotate the orientation of the AIModel wrt the horizontal
647 hlTrans *= SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
649 // The offset converted to the usual body fixed coordinate system
650 // rotated to the earth fixed coordinates axis
651 SGVec3d off = hlTrans.backTransform(_off);
653 // Add the position offset of the AIModel to gain the earth centered position
654 SGVec3d cartPos = SGVec3d::fromGeod(pos);
656 return cartPos + off;
659 SGVec3d FGAIBase::getCartPos() const {
660 SGVec3d cartPos = SGVec3d::fromGeod(pos);
664 bool FGAIBase::getGroundElevationM(const SGGeod& pos, double& elev,
665 const simgear::BVHMaterial** material) const {
666 return globals->get_scenery()->get_elevation_m(pos, elev, material,
670 double FGAIBase::_getCartPosX() const {
671 SGVec3d cartPos = getCartPos();
675 double FGAIBase::_getCartPosY() const {
676 SGVec3d cartPos = getCartPos();
680 double FGAIBase::_getCartPosZ() const {
681 SGVec3d cartPos = getCartPos();
685 void FGAIBase::_setLongitude( double longitude ) {
686 pos.setLongitudeDeg(longitude);
689 void FGAIBase::_setLatitude ( double latitude ) {
690 pos.setLatitudeDeg(latitude);
693 void FGAIBase::_setSubID( int s ) {
697 bool FGAIBase::setParentNode() {
700 SG_LOG(SG_AI, SG_ALERT, "AIBase: " << _name
701 << " parent not set ");
705 const SGPropertyNode_ptr ai = fgGetNode("/ai/models", true);
707 for (int i = ai->nChildren() - 1; i >= -1; i--) {
708 SGPropertyNode_ptr model;
710 if (i < 0) { // last iteration: selected model
711 model = _selected_ac;
713 model = ai->getChild(i);
714 //const string& path = ai->getPath();
715 const string name = model->getStringValue("name");
717 if (!model->nChildren()){
720 if (name == _parent) {
721 _selected_ac = model; // save selected model for last iteration
731 if (_selected_ac != 0){
732 const string name = _selected_ac->getStringValue("name");
735 SG_LOG(SG_AI, SG_ALERT, "AIBase: " << _name
736 << " parent not found: dying ");
743 double FGAIBase::_getLongitude() const {
744 return pos.getLongitudeDeg();
747 double FGAIBase::_getLatitude() const {
748 return pos.getLatitudeDeg();
751 double FGAIBase::_getElevationFt() const {
752 return pos.getElevationFt();
755 double FGAIBase::_getRdot() const {
759 double FGAIBase::_getVS_fps() const {
763 double FGAIBase::_get_speed_east_fps() const {
764 return speed_east_deg_sec * ft_per_deg_lon;
767 double FGAIBase::_get_speed_north_fps() const {
768 return speed_north_deg_sec * ft_per_deg_lat;
771 void FGAIBase::_setVS_fps( double _vs ) {
775 double FGAIBase::_getAltitude() const {
779 double FGAIBase::_getAltitudeAGL(SGGeod inpos, double start){
780 getGroundElevationM(SGGeod::fromGeodM(inpos, start),
782 return inpos.getElevationFt() - _elevation_m * SG_METER_TO_FEET;
785 bool FGAIBase::_getServiceable() const {
789 SGPropertyNode* FGAIBase::_getProps() const {
793 void FGAIBase::_setAltitude( double _alt ) {
797 bool FGAIBase::_isNight() {
798 return (fgGetFloat("/sim/time/sun-angle-rad") > 1.57);
801 bool FGAIBase::_getCollisionData() {
802 return _collision_reported;
805 bool FGAIBase::_getExpiryData() {
806 return _expiry_reported;
809 bool FGAIBase::_getImpactData() {
810 return _impact_reported;
813 double FGAIBase::_getImpactLat() const {
817 double FGAIBase::_getImpactLon() const {
821 double FGAIBase::_getImpactElevFt() const {
822 return _impact_elev * SG_METER_TO_FEET;
825 double FGAIBase::_getImpactPitch() const {
826 return _impact_pitch;
829 double FGAIBase::_getImpactRoll() const {
833 double FGAIBase::_getImpactHdg() const {
837 double FGAIBase::_getImpactSpeed() const {
838 return _impact_speed;
841 int FGAIBase::getID() const {
845 int FGAIBase::_getSubID() const {
849 double FGAIBase::_getSpeed() const {
853 double FGAIBase::_getRoll() const {
857 double FGAIBase::_getPitch() const {
861 double FGAIBase::_getHeading() const {
865 double FGAIBase::_getXOffset() const {
869 double FGAIBase::_getYOffset() const {
873 double FGAIBase::_getZOffset() const {
877 const char* FGAIBase::_getPath() const {
878 return model_path.c_str();
881 const char* FGAIBase::_getSMPath() const {
882 return _path.c_str();
885 const char* FGAIBase::_getName() const {
886 return _name.c_str();
889 const char* FGAIBase::_getCallsign() const {
890 return _callsign.c_str();
893 const char* FGAIBase::_getSubmodel() const {
894 return _submodel.c_str();
897 void FGAIBase::CalculateMach() {
898 // Calculate rho at altitude, using standard atmosphere
899 // For the temperature T and the pressure p,
900 double altitude = altitude_ft;
902 if (altitude < 36152) { // curve fits for the troposphere
903 T = 59 - 0.00356 * altitude;
904 p = 2116 * pow( ((T + 459.7) / 518.6) , 5.256);
905 } else if ( 36152 < altitude && altitude < 82345 ) { // lower stratosphere
907 p = 473.1 * pow( e , 1.73 - (0.000048 * altitude) );
908 } else { // upper stratosphere
909 T = -205.05 + (0.00164 * altitude);
910 p = 51.97 * pow( ((T + 459.7) / 389.98) , -11.388);
913 rho = p / (1718 * (T + 459.7));
915 // calculate the speed of sound at altitude
916 // a = sqrt ( g * R * (T + 459.7))
918 // a = speed of sound [ft/s]
919 // g = specific heat ratio, which is usually equal to 1.4
920 // R = specific gas constant, which equals 1716 ft-lb/slug/R
921 a = sqrt ( 1.4 * 1716 * (T + 459.7));
923 // calculate Mach number
926 // cout << "Speed(ft/s) "<< speed <<" Altitude(ft) "<< altitude << " Mach " << Mach << endl;
929 int FGAIBase::_newAIModelID() {
933 id++; // id = 0 is not allowed.
938 bool FGAIBase::isValid() {
939 //Either no flightplan or it is valid
940 return !fp || fp->isValidPlan();