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1 // FGAIAircraft - FGAIBase-derived class creates an AI airplane
2 //
3 // Written by David Culp, started October 2003.
4 //
5 // Copyright (C) 2003  David P. Culp - davidculp2@comcast.net
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 #ifdef HAVE_CONFIG_H
22 #  include <config.h>
23 #endif
24
25 #include <simgear/math/point3d.hxx>
26 #include <simgear/route/waypoint.hxx>
27 #include <Main/fg_props.hxx>
28 #include <Main/globals.hxx>
29 #include <Main/viewer.hxx>
30 #include <Scenery/scenery.hxx>
31 #include <Scenery/tilemgr.hxx>
32
33 #include <string>
34 #include <math.h>
35 #include <time.h>
36 #ifdef _MSC_VER
37 #  include <float.h>
38 #  define finite _finite
39 #elif defined(__sun) || defined(sgi)
40 #  include <ieeefp.h>
41 #endif
42
43 SG_USING_STD(string);
44
45 #include "AIAircraft.hxx"
46 //#include <Airports/trafficcontroller.hxx>
47    static string tempReg;
48 //
49 // accel, decel, climb_rate, descent_rate, takeoff_speed, climb_speed,
50 // cruise_speed, descent_speed, land_speed
51 //
52 const FGAIAircraft::PERF_STRUCT FGAIAircraft::settings[] = {
53     // light aircraft
54     {2.0, 2.0,  450.0, 1000.0,  70.0,  80.0, 100.0,  80.0,  60.0},
55     // ww2_fighter
56     {4.0, 2.0, 3000.0, 1500.0, 110.0, 180.0, 250.0, 200.0, 100.0},
57     // jet_transport
58     {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0},
59     // jet_fighter
60     {7.0, 3.0, 4000.0, 2000.0, 150.0, 350.0, 500.0, 350.0, 150.0},
61     // tanker
62     {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0},
63     // ufo (extreme accel/decel)
64     {30.0, 30.0, 6000.0, 6000.0, 150.0, 300.0, 430.0, 300.0, 130.0}
65 };
66
67
68 FGAIAircraft::FGAIAircraft(FGAISchedule *ref) :
69     FGAIBase(otAircraft)
70 {
71     trafficRef = ref;
72     if (trafficRef)
73         groundOffset = trafficRef->getGroundOffset();
74     else
75         groundOffset = 0;
76
77     fp = 0;
78     controller = 0;
79     prevController = 0;
80     dt_count = 0;
81     dt_elev_count = 0;
82     use_perf_vs = true;
83     isTanker = false;
84
85     no_roll = false;
86     tgt_speed = 0;
87     speed = 0;
88     groundTargetSpeed = 0;
89
90     // set heading and altitude locks
91     hdg_lock = false;
92     alt_lock = false;
93     roll = 0;
94     headingChangeRate = 0.0;
95
96     holdPos = false;
97 }
98
99
100 FGAIAircraft::~FGAIAircraft() {
101     //delete fp;
102   if (controller)
103     controller->signOff(getID());
104 }
105
106
107 void FGAIAircraft::readFromScenario(SGPropertyNode* scFileNode) {
108     if (!scFileNode)
109         return;
110
111     FGAIBase::readFromScenario(scFileNode);
112
113     setPerformance(scFileNode->getStringValue("class", "jet_transport"));
114     setFlightPlan(scFileNode->getStringValue("flightplan"),
115                   scFileNode->getBoolValue("repeat", false));
116     setCallSign(scFileNode->getStringValue("callsign"));
117     setTACANChannelID(scFileNode->getStringValue("TACAN-channel-ID"));
118 }
119
120
121 bool FGAIAircraft::init() {
122     //refuel_node = fgGetNode("systems/refuel/contact", true);
123     return FGAIBase::init(true);
124 }
125
126
127 void FGAIAircraft::bind() {
128     FGAIBase::bind();
129
130     props->tie("controls/gear/gear-down",
131                SGRawValueMethods<FGAIAircraft,bool>(*this,
132                                               &FGAIAircraft::_getGearDown));
133     props->tie("refuel/contact", SGRawValuePointer<bool>(&contact));
134     props->setStringValue("callsign", callsign.c_str());
135     props->setStringValue("navaids/tacan/channel-ID", TACAN_channel_id.c_str());
136     props->setBoolValue("tanker",isTanker);
137 }
138
139
140 void FGAIAircraft::unbind() {
141     FGAIBase::unbind();
142
143     props->untie("controls/gear/gear-down");
144     props->untie("refuel/contact");
145 }
146
147
148 void FGAIAircraft::update(double dt) {
149     FGAIBase::update(dt);
150     Run(dt);
151     Transform();
152 }
153
154
155 void FGAIAircraft::setPerformance(const std::string& acclass) {
156     if (acclass == "light") {
157         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::LIGHT]);
158     } else if (acclass == "ww2_fighter") {
159         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::WW2_FIGHTER]);
160     } else if (acclass == "jet_transport") {
161         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
162     } else if (acclass == "jet_fighter") {
163         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_FIGHTER]);
164     } else if (acclass == "tanker") {
165         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
166         SetTanker(true);
167     } else if (acclass == "ufo") {
168         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::UFO]);
169     } else {
170         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
171     }
172 }
173
174
175 void FGAIAircraft::SetPerformance(const PERF_STRUCT *ps) {
176
177    performance = ps;
178 }
179
180
181 void FGAIAircraft::Run(double dt) {
182
183     FGAIAircraft::dt = dt;
184     
185     if (fp) {
186         time_t now = time(NULL) + fgGetLong("/sim/time/warp");
187         ProcessFlightPlan(dt, now);
188         if (now < fp->getStartTime()) {
189             // Do execute Ground elev for inactive aircraft, so they
190             // Are repositioned to the correct ground altitude when the user flies within visibility range.
191             // In addition, check whether we are out of user range, so this aircraft
192             // can be deleted.
193             if (no_roll) {
194                 Transform();       // make sure aip is initialized.
195                 if (trafficRef) {
196                   double userLatitude  = fgGetDouble("/position/latitude-deg");
197                   double userLongitude = fgGetDouble("/position/longitude-deg");
198                   double course, distance;
199                   SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
200                   SGWayPoint user (userLongitude, userLatitude, 0);
201                   user.CourseAndDistance(current, &course, &distance);
202                   if ((distance * SG_METER_TO_NM) > TRAFFICTOAIDIST) {
203                     setDie(true);
204                     return;
205                   }
206                   getGroundElev(dt); // make sure it's exectuted first time around, so force a large dt value
207                   //getGroundElev(dt); // Need to do this twice.
208                   //cerr << trafficRef->getRegistration() << " Setting altitude to " << tgt_altitude;
209                   doGroundAltitude();
210                   //cerr << " Actual altitude " << altitude << endl;
211                   // Transform();
212                   pos.setElevationFt(altitude_ft);
213                 }
214             }
215             return;
216         }
217     } else {
218         // no flight plan, update target heading, speed, and altitude
219         // from control properties.  These default to the initial
220         // settings in the config file, but can be changed "on the
221         // fly".
222         string lat_mode = props->getStringValue("controls/flight/lateral-mode");
223         if ( lat_mode == "roll" ) {
224             double angle
225                 = props->getDoubleValue("controls/flight/target-roll" );
226             RollTo( angle );
227         } else {
228              double angle
229                 = props->getDoubleValue("controls/flight/target-hdg" );
230             TurnTo( angle );
231         }
232
233         string lon_mode
234             = props->getStringValue("controls/flight/longitude-mode");
235         if ( lon_mode == "alt" ) {
236             double alt = props->getDoubleValue("controls/flight/target-alt" );
237             ClimbTo( alt );
238         } else {
239             double angle
240                 = props->getDoubleValue("controls/flight/target-pitch" );
241             PitchTo( angle );
242         }
243
244         AccelTo( props->getDoubleValue("controls/flight/target-spd" ) );
245     }
246     if (controller)
247       {
248         controller->update(getID(), 
249                            pos.getLatitudeDeg(), 
250                            pos.getLongitudeDeg(),
251                            hdg,
252                            speed,
253                            altitude_ft, dt);
254         processATC(controller->getInstruction(getID()));
255       }
256       
257     double turn_radius_ft;
258     double turn_circum_ft;
259     double speed_north_deg_sec;
260     double speed_east_deg_sec;
261     double dist_covered_ft;
262     double alpha;
263
264     // adjust speed
265     double speed_diff; //= tgt_speed - speed;
266     if (!no_roll) {
267         speed_diff = tgt_speed - speed;
268     } else {
269         speed_diff = groundTargetSpeed - speed;
270     }
271
272     if (speed_diff > 0.0) {
273         speed += performance->accel * dt;
274         if (no_roll) { // apply overshoot correction
275           if ( speed > groundTargetSpeed ) speed = groundTargetSpeed;
276         }else {
277           if ( speed > tgt_speed ) speed = tgt_speed;
278         }
279     } else if (speed_diff < 0.0) {
280         if (no_roll) {
281             // on ground (aircraft can't roll)
282             // deceleration performance is better due to wheel brakes.
283             speed -= performance->decel * dt * 3;
284         } else {
285             speed -= performance->decel * dt;
286         }
287         if (no_roll) { // apply overshoot correction
288         if (speed < groundTargetSpeed ) speed = groundTargetSpeed;
289         } else { 
290           if ( speed < tgt_speed ) speed = tgt_speed;
291         }
292     }
293     
294     
295     // convert speed to degrees per second
296     speed_north_deg_sec = cos( hdg * SGD_DEGREES_TO_RADIANS )
297                           * speed * 1.686 / ft_per_deg_lat;
298     speed_east_deg_sec  = sin( hdg * SGD_DEGREES_TO_RADIANS )
299                           * speed * 1.686 / ft_per_deg_lon;
300
301     // set new position
302     pos.setLatitudeDeg( pos.getLatitudeDeg() + speed_north_deg_sec * dt);
303     pos.setLongitudeDeg( pos.getLongitudeDeg() + speed_east_deg_sec * dt); 
304
305     /* printf("%.7f %0.4f %.7f %.5f %.7f %.7f %.8f %.8f %.9f %.9f\n",
306            dt, hdg, speed, ft_per_deg_lat,
307            cos( hdg * SGD_DEGREES_TO_RADIANS ),
308            speed * 1.686 / ft_per_deg_lat,
309            speed_north_deg_sec, speed_east_deg_sec,
310            pos.getLatitudeDeg(), pos.getLongitudeDeg()); */
311
312     //if (!(finite(pos.lat()) && finite(pos.lon())))
313     //  {
314     //    cerr << "Position is not finite" << endl;
315     //    cerr << "speed = " << speed << endl;
316     //    cerr << "dt" << dt << endl;
317     //    cerr << "heading " << hdg << endl;
318     //    cerr << "speed east " << speed_east_deg_sec << endl;
319     //    cerr << "speed nrth " << speed_north_deg_sec << endl;
320     //    cerr << "deg_lat    " << ft_per_deg_lat << endl;
321     //    cerr << "deg_lon    " << ft_per_deg_lon << endl;
322     //  }
323
324     // adjust heading based on current bank angle
325     if (roll == 0.0)
326         roll = 0.01;
327
328     if (roll != 0.0) {
329         // double turnConstant;
330         //if (no_roll)
331         //  turnConstant = 0.0088362;
332         //else
333         //  turnConstant = 0.088362;
334         // If on ground, calculate heading change directly
335         if (no_roll) {
336             double headingDiff = fabs(hdg-tgt_heading);
337
338             if (headingDiff > 180)
339                 headingDiff = fabs(headingDiff - 360);
340
341             groundTargetSpeed = tgt_speed - (tgt_speed * (headingDiff/45));
342             if (sign(groundTargetSpeed) != sign(tgt_speed))
343                 groundTargetSpeed = 0.21 * sign(tgt_speed); // to prevent speed getting stuck in 'negative' mode
344
345             if (headingDiff > 30.0) {
346                 headingChangeRate += dt * sign(roll); // invert if pushed backward
347                 // Print some debug statements to find out why aircraft may get stuck
348                 // forever turning
349                 //if (trafficRef->getDepartureAirport()->getId() == string("EHAM")) {
350                 //    cerr << "Turning : " << trafficRef->getRegistration()
351                 //    cerr <<  " Speed = " << speed << " Heading " << hdg
352                 //         << " Target Heading " << tgt_heading
353                 //         << " Lead Distance " <<  fp->getLeadDistance()
354                 //         << " Distance to go "
355                 //         << fp->getDistanceToGo(pos.lat(), pos.lon(), fp->getCurrentWaypoint())
356                 //         << "waypoint name " << fp->getCurrentWaypoint()->name
357                 //         << endl;
358                 //}
359                 if (headingChangeRate > 30)
360                     headingChangeRate = 30;
361                 else if (headingChangeRate < -30)
362                     headingChangeRate = -30;
363
364             } else {
365                 if (fabs(headingChangeRate) > headingDiff)
366                     headingChangeRate = headingDiff*sign(roll);
367                 else
368                     headingChangeRate += dt * sign(roll);
369             }
370             hdg += headingChangeRate * dt;
371             //cerr << "On ground. Heading: " << hdg << ". Target Heading: " << tgt_heading
372             //     << ". Target speed: " << groundTargetSpeed << ". heading change rate"
373             //     << headingChangeRate << endl;
374
375         } else {
376             if (fabs(speed) > 1.0) {
377                 turn_radius_ft = 0.088362 * speed * speed
378                         / tan( fabs(roll) / SG_RADIANS_TO_DEGREES );
379             } else {
380                 turn_radius_ft = 1.0; // Check if turn_radius_ft == 0; this might lead to a division by 0.
381             }
382             turn_circum_ft = SGD_2PI * turn_radius_ft;
383             dist_covered_ft = speed * 1.686 * dt;
384             alpha = dist_covered_ft / turn_circum_ft * 360.0;
385             hdg += alpha * sign(roll);
386         }
387         while ( hdg > 360.0 ) {
388             hdg -= 360.0;
389             spinCounter++;
390         }
391         while ( hdg < 0.0) {
392             hdg += 360.0;
393             spinCounter--;
394         }
395     }
396
397
398     // adjust target bank angle if heading lock engaged
399     if (hdg_lock) {
400         double bank_sense = 0.0;
401         double diff = fabs(hdg - tgt_heading);
402         if (diff > 180)
403             diff = fabs(diff - 360);
404
405         double sum = hdg + diff;
406         if (sum > 360.0)
407             sum -= 360.0;
408         if (fabs(sum - tgt_heading) < 1.0) {
409             bank_sense = 1.0;   // right turn
410         } else {
411             bank_sense = -1.0;  // left turn
412         }
413         if (diff < 30) {
414             tgt_roll = diff * bank_sense;
415         } else {
416             tgt_roll = 30.0 * bank_sense;
417         }
418         if ((fabs((double) spinCounter) > 1) && (diff > 30)) {
419             tgt_speed *= 0.999; // Ugly hack: If aircraft get stuck, they will continually spin around.
420             // The only way to resolve this is to make them slow down.
421             //if (tempReg.empty())
422             //  tempReg = trafficRef->getRegistration();
423             //if (trafficRef->getRegistration() == tempReg) {
424             //    cerr << trafficRef->getRegistration()
425             //         << " appears to be spinning: " << spinCounter << endl
426             //         << " speed          " << speed << endl
427             //         << " heading        " << hdg << endl
428             //         << " lead distance  " << fp->getLeadDistance() << endl
429             //         << " waypoint       " << fp->getCurrentWaypoint()->name
430             //         << " target heading " << tgt_heading << endl
431             //         << " lead in angle  " << fp->getLeadInAngle()<< endl
432             //         << " roll           " << roll << endl
433             //         << " target_roll    " << tgt_roll << endl;
434             //}
435         }
436     }
437
438     // adjust bank angle, use 9 degrees per second
439     double bank_diff = tgt_roll - roll;
440     if (fabs(bank_diff) > 0.2) {
441         if (bank_diff > 0.0)
442             roll += 9.0 * dt;
443
444         if (bank_diff < 0.0)
445             roll -= 9.0 * dt;
446         //while (roll > 180) roll -= 360;
447         //while (roll < 180) roll += 360;
448     }
449
450     // adjust altitude (meters) based on current vertical speed (fpm)
451     altitude_ft += vs / 60.0 * dt;
452     pos.setElevationFt(altitude_ft);  
453
454     // adjust target Altitude, based on ground elevation when on ground
455     if (no_roll) {
456         getGroundElev(dt);
457         doGroundAltitude();
458     } else {
459         // find target vertical speed if altitude lock engaged
460         if (alt_lock && use_perf_vs) {
461             if (altitude_ft < tgt_altitude_ft) {
462                 tgt_vs = tgt_altitude_ft - altitude_ft;
463                 if (tgt_vs > performance->climb_rate)
464                     tgt_vs = performance->climb_rate;
465             } else {
466                 tgt_vs = tgt_altitude_ft - altitude_ft;
467                 if (tgt_vs  < (-performance->descent_rate))
468                     tgt_vs = -performance->descent_rate;
469             }
470         }
471
472         if (alt_lock && !use_perf_vs) {
473             double max_vs = 4*(tgt_altitude_ft - altitude_ft);
474             double min_vs = 100;
475             if (tgt_altitude_ft < altitude_ft)
476                 min_vs = -100.0;
477             if ((fabs(tgt_altitude_ft - altitude_ft) < 1500.0)
478                     && (fabs(max_vs) < fabs(tgt_vs)))
479                 tgt_vs = max_vs;
480
481             if (fabs(tgt_vs) < fabs(min_vs))
482                 tgt_vs = min_vs;
483         }
484     }
485     // adjust vertical speed
486     double vs_diff = tgt_vs - vs;
487     if (fabs(vs_diff) > 10.0) {
488         if (vs_diff > 0.0) {
489             vs += (performance->climb_rate / 3.0) * dt;
490
491             if (vs > tgt_vs)
492                 vs = tgt_vs;
493         } else {
494             vs -= (performance->descent_rate / 3.0) * dt;
495
496            if (vs < tgt_vs)
497                vs = tgt_vs;
498         }
499     }
500
501     // match pitch angle to vertical speed
502     if (vs > 0) {
503         pitch = vs * 0.005;
504     } else {
505         pitch = vs * 0.002;
506     }
507
508     //###########################//
509     // do calculations for radar //
510     //###########################//
511     double range_ft2 = UpdateRadar(manager);
512
513     //************************************//
514     // Tanker code                        //
515     //************************************//
516
517     if ( isTanker) {
518         if ( (range_ft2 < 250.0 * 250.0) && (y_shift > 0.0)
519                 && (elevation > 0.0) ) {
520             //refuel_node->setBoolValue(true);
521             contact = true;
522         } else {
523             //refuel_node->setBoolValue(false);
524             contact = false;
525         }
526     } else {
527         contact = false;
528     }
529 }
530
531
532 void FGAIAircraft::AccelTo(double speed) {
533     tgt_speed = speed;
534 }
535
536
537 void FGAIAircraft::PitchTo(double angle) {
538     tgt_pitch = angle;
539     alt_lock = false;
540 }
541
542
543 void FGAIAircraft::RollTo(double angle) {
544     tgt_roll = angle;
545     hdg_lock = false;
546 }
547
548
549 void FGAIAircraft::YawTo(double angle) {
550     tgt_yaw = angle;
551 }
552
553
554 void FGAIAircraft::ClimbTo(double alt_ft ) {
555     tgt_altitude_ft = alt_ft;
556     alt_lock = true;
557 }
558
559
560 void FGAIAircraft::TurnTo(double heading) {
561     tgt_heading = heading;
562     hdg_lock = true;
563 }
564
565
566 double FGAIAircraft::sign(double x) {
567     if ( x < 0.0 )
568         return -1.0;
569     else
570         return 1.0;
571 }
572
573
574 void FGAIAircraft::setFlightPlan(const std::string& flightplan, bool repeat) {
575     if (!flightplan.empty()) {
576         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
577         fp->setRepeat(repeat);
578         SetFlightPlan(fp);
579     }
580 }
581
582
583 void FGAIAircraft::SetFlightPlan(FGAIFlightPlan *f) {
584     delete fp;
585     fp = f;
586 }
587
588
589 void FGAIAircraft::ProcessFlightPlan( double dt, time_t now ) {
590     bool eraseWaypoints;
591     if (trafficRef) {
592         eraseWaypoints = true;
593     } else
594         eraseWaypoints = false;
595
596  
597     FGAIFlightPlan::waypoint* prev = 0; // the one behind you
598     FGAIFlightPlan::waypoint* curr = 0; // the one ahead
599     FGAIFlightPlan::waypoint* next = 0; // the next plus 1
600     prev = fp->getPreviousWaypoint();
601     curr = fp->getCurrentWaypoint();
602     next = fp->getNextWaypoint();
603     dt_count += dt;
604
605     ///////////////////////////////////////////////////////////////////////////
606     // Initialize the flightplan
607     //////////////////////////////////////////////////////////////////////////
608     if (!prev) {
609
610       spinCounter = 0;
611       tempReg = "";
612       fp->IncrementWaypoint(eraseWaypoints);
613       if (!(fp->getNextWaypoint()) && trafficRef)
614         loadNextLeg();
615       
616       prev = fp->getPreviousWaypoint(); //first waypoint
617       curr = fp->getCurrentWaypoint();  //second waypoint
618       next = fp->getNextWaypoint();     //third waypoint (might not exist!)
619       
620       setLatitude(prev->latitude);
621       setLongitude(prev->longitude);
622       setSpeed(prev->speed);
623       setAltitude(prev->altitude);
624       
625       if (prev->speed > 0.0)
626         setHeading(fp->getBearing(prev->latitude, prev->longitude, curr));
627       else
628         setHeading(fp->getBearing(curr->latitude, curr->longitude, prev));
629       
630       // If next doesn't exist, as in incrementally created flightplans for
631       // AI/Trafficmanager created plans,
632       // Make sure lead distance is initialized otherwise
633       if (next)
634         fp->setLeadDistance(speed, hdg, curr, next);
635       
636       if (curr->crossat > -1000.0) { //use a calculated descent/climb rate
637         use_perf_vs = false;
638         tgt_vs = (curr->crossat - prev->altitude)
639           / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
640              / 6076.0 / prev->speed*60.0);
641         tgt_altitude_ft = curr->crossat;
642       } else {
643         use_perf_vs = true;
644         tgt_altitude_ft = prev->altitude;
645       }
646       alt_lock = hdg_lock = true;
647       no_roll = prev->on_ground;
648       if (no_roll) {
649         Transform();         // make sure aip is initialized.
650         getGroundElev(60.1); // make sure it's executed first time around, so force a large dt value
651         doGroundAltitude(); 
652       }
653       // Make sure to announce the aircraft's position 
654       announcePositionToController();
655       prevSpeed = 0;
656       return;
657     } // end of initialization
658      ///////////////////////////////////////////////////////////////////////////
659     // Check Execution time (currently once every 100 ms) 
660     // Add a bit of randomization to prevent the execution of all flight plans
661     // in synchrony, which can add significant periodic framerate flutter.
662     ///////////////////////////////////////////////////////////////////////////
663     double rand_exec_time = (rand() % 100) / 100;
664     if ((dt_count < (0.1+rand_exec_time)) || (now < fp->getStartTime())) {
665       //cerr  << "done fp dt" << endl;
666       return;
667     } else {
668       dt_count = 0;
669     }
670
671     // check to see if we've reached the lead point for our next turn
672     double dist_to_go = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
673
674     //cerr << "2" << endl;
675     double lead_dist = fp->getLeadDistance();
676     //cerr << " Distance : " << dist_to_go << ": Lead distance " << lead_dist << endl;
677     // experimental: Use fabs, because speed can be negative (I hope) during push_back.
678
679     if (lead_dist < fabs(2*speed)) {
680         lead_dist = fabs(2*speed);  //don't skip over the waypoint
681         //cerr << "Extending lead distance to " << lead_dist << endl;
682     }
683
684     //prev_dist_to_go = dist_to_go;
685
686     if ( dist_to_go < lead_dist ) {
687         if (curr->finished) {  //end of the flight plan
688             if (fp->getRepeat())
689                 fp->restart();
690             else
691                 setDie(true);
692             return;
693         }
694
695         if (next) {
696             tgt_heading = fp->getBearing(curr, next);
697             spinCounter = 0;
698         }
699
700         fp->IncrementWaypoint(eraseWaypoints);
701         if (!(fp->getNextWaypoint()) && trafficRef)
702             loadNextLeg();
703
704         prev = fp->getPreviousWaypoint();
705         curr = fp->getCurrentWaypoint();
706         next = fp->getNextWaypoint();
707
708         // Now that we have incremented the waypoints, excute some traffic manager specific code
709         if (trafficRef) {
710             double userLatitude  = fgGetDouble("/position/latitude-deg");
711             double userLongitude = fgGetDouble("/position/longitude-deg");
712             double course, distance;
713             SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
714             SGWayPoint user (userLongitude, userLatitude, 0);
715             user.CourseAndDistance(current, &course, &distance);
716             if ((distance * SG_METER_TO_NM) > TRAFFICTOAIDIST) {
717                 setDie(true);
718                 return;
719             }
720
721             FGAirport * dep = trafficRef->getDepartureAirport();
722             FGAirport * arr = trafficRef->getArrivalAirport();
723             if (!( dep && arr)) {
724                 setDie(true);
725                 return;
726             }
727             // This waypoint marks the fact that the aircraft has passed the initial taxi
728             // departure waypoint, so it can release the parking.
729             if (prev->name == "park2")
730                 dep->getDynamics()->releaseParking(fp->getGate());
731             // This is the last taxi waypoint, and marks the the end of the flight plan
732             // so, the schedule should update and wait for the next departure time. 
733             if (prev->name == "END") {
734               // make sure to wait at least 20 minutes at parking to prevent "nervous" taxi behavior
735               // delayed aircraft. 
736               time_t nextDeparture = trafficRef->getDepartureTime();
737               if (nextDeparture < (now+1200)) {
738                 nextDeparture = now + 1200; 
739               }
740               fp->setTime(trafficRef->getDepartureTime());
741             }
742             announcePositionToController();
743             
744         }
745
746         if (next) {
747             //cerr << "Current waypoint" << curr->name << endl;
748             //cerr << "Next waypoint" << next->name << endl;
749             fp->setLeadDistance(speed, tgt_heading, curr, next);
750         }
751
752         //cerr << "5.1" << endl;
753         if (!(prev->on_ground)) { // only update the tgt altitude from flightplan if not on the ground
754             tgt_altitude_ft = prev->altitude;
755             if (curr->crossat > -1000.0) {
756                 //cerr << "5.1a" << endl;
757                 use_perf_vs = false;
758                 tgt_vs = (curr->crossat - altitude_ft) / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
759                         / 6076.0 / speed*60.0);
760                 //cerr << "5.1b" << endl;
761                 tgt_altitude_ft = curr->crossat;
762             } else {
763                 //cerr << "5.1c" << endl;
764                 use_perf_vs = true;
765                 //cerr << "5.1d" << endl;
766                 //cerr << "Setting target altitude : " <<tgt_altitude_ft << endl;
767             }
768         }
769         //cerr << "6" << endl;
770         tgt_speed = prev->speed;
771         hdg_lock = alt_lock = true;
772         no_roll = prev->on_ground;
773         //cout << "Crossing waypoint: " << prev->name << endl;
774         //cout << "  Target speed:    " << tgt_speed << endl;
775         //cout << "  Target altitude: " << tgt_altitude_ft << endl;
776         //cout << "  Target heading:  " << tgt_heading << endl << endl;
777
778     } else {
779         double calc_bearing = fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
780         //cerr << "Bearing = " << calc_bearing << endl;
781         if (speed < 0) {
782             calc_bearing +=180;
783             if (calc_bearing > 360)
784                 calc_bearing -= 360;
785         }
786
787         if (finite(calc_bearing)) {
788             double hdg_error = calc_bearing - tgt_heading;
789             if (fabs(hdg_error) > 1.0) {
790                 TurnTo( calc_bearing );
791             }
792
793         } else {
794             cerr << "calc_bearing is not a finite number : "
795                  << "Speed " << speed
796                  << "pos : " << pos.getLatitudeDeg() << ", " << pos.getLongitudeDeg()
797                  << "waypoint " << curr->latitude << ", " << curr->longitude << endl;
798             cerr << "waypoint name " << curr->name;
799             exit(1);  // FIXME
800         }
801
802         double speed_diff = speed - prevSpeed;
803         // Update the lead distance calculation if speed has changed sufficiently
804         // to prevent spinning (hopefully);
805         if (fabs(speed_diff) > 10) {
806             prevSpeed = speed;
807             fp->setLeadDistance(speed, tgt_heading, curr, next);
808         }
809
810         //cerr << "Done Processing FlightPlan"<< endl;
811     }
812 }
813
814 void FGAIAircraft::initializeFlightPlan() 
815 {
816
817 }
818
819
820 bool FGAIAircraft::_getGearDown() const {
821     return ((props->getFloatValue("position/altitude-agl-ft") < 900.0)
822             && (props->getFloatValue("velocities/airspeed-kt")
823             < performance->land_speed*1.25));
824 }
825
826
827 void FGAIAircraft::loadNextLeg() {
828     //delete fp;
829     //time_t now = time(NULL) + fgGetLong("/sim/time/warp");
830
831     //FGAIModelEntity entity;
832     //entity.m_class = "jet_transport";
833     //entity.path = modelPath.c_str();
834     //entity.flightplan = "none";
835     //entity.latitude = _getLatitude();
836     //entity.longitude = _getLongitude();
837     //entity.altitude = trafficRef->getCruiseAlt() * 100; // convert from FL to feet
838     //entity.speed = 450; // HACK ALERT
839     //entity.fp = new FGAIFlightPlan(&entity, courseToDest, i->getDepartureTime(), dep, arr);
840     int leg;
841     if ((leg = fp->getLeg())  == 10) {
842         trafficRef->next();
843         leg = 1;
844         fp->setLeg(leg);
845         //cerr << "Resetting leg : " << leg << endl;
846     }
847     //leg++;
848     //fp->setLeg(leg);
849     //cerr << "Creating leg number : " << leg << endl;
850     FGAirport *dep = trafficRef->getDepartureAirport();
851     FGAirport *arr = trafficRef->getArrivalAirport();
852     if (!(dep && arr)) {
853         setDie(true);
854         //cerr << "Failed to get airport in AIAircraft::ProcessFlightplan()" << endl;
855         //if (dep)
856         //  cerr << "Departure " << dep->getId() << endl;
857         //if (arr)
858         //  cerr << "Arrival   " << arr->getId() << endl;
859
860     } else {
861         double cruiseAlt = trafficRef->getCruiseAlt() * 100;
862         //cerr << "Creating new leg using " << cruiseAlt << " as cruise altitude."<< endl;
863
864         fp->create (dep,
865                     arr,
866                     leg,
867                     cruiseAlt, //(trafficRef->getCruiseAlt() * 100), // convert from FL to feet
868                     trafficRef->getSpeed(),
869                     _getLatitude(),
870                     _getLongitude(),
871                     false,
872                     trafficRef->getRadius(),
873                     trafficRef->getFlightType(),
874                     acType,
875                     company);
876         //prev = fp->getPreviousWaypoint();
877         //curr = fp->getCurrentWaypoint();
878         //next = fp->getNextWaypoint();
879         //cerr << "25" << endl;
880         //if (next)
881         //        {
882         //  //cerr << "Next waypoint" << next->name << endl;
883         //          fp->setLeadDistance(speed, tgt_heading, curr, next);
884         //        }
885         //cerr << "25.1" << endl;
886         //if (curr->crossat > -1000.0) {
887         //        //cerr << "25.1a" << endl;
888         //        use_perf_vs = false;
889         //
890         //        tgt_vs = (curr->crossat - altitude_ft)/
891         //          (fp->getDistanceToGo(pos.lat(), pos.lon(), curr)/6076.0/speed*60.0);
892         //        //cerr << "25.1b" << endl;
893         //        tgt_altitude_ft = curr->crossat;
894         //} else {
895         //        //cerr << "25.1c" << endl;
896         //        use_perf_vs = true;
897         //        //cerr << "25.1d" << endl;
898         //        tgt_altitude_ft = prev->altitude;
899         //        //cerr << "Setting target altitude : " <<tgt_altitude_ft << endl;
900         // }
901         //cerr << "26" << endl;
902         //tgt_speed = prev->speed;
903         //hdg_lock = alt_lock = true;
904         //no_roll = prev->on_ground;
905     }
906     //else
907     //{
908     //delete entity.fp;
909     //entity.fp = new FGAIFlightPlan(&entity,
910     //                                 999,  // A hack
911     //                                 trafficRef->getDepartureTime(),
912     //                                 trafficRef->getDepartureAirport(),
913     //                                 trafficRef->getArrivalAirport(),
914     //                                 false,
915     //                                 acType,
916     //                                 company);
917     //SetFlightPlan(entity.fp);
918 }
919
920
921 // Note: This code is copied from David Luff's AILocalTraffic
922 // Warning - ground elev determination is CPU intensive
923 // Either this function or the logic of how often it is called
924 // will almost certainly change.
925
926 void FGAIAircraft::getGroundElev(double dt) {
927     dt_elev_count += dt;
928
929     // Update minimally every three secs, but add some randomness
930     // to prevent all IA objects doing this in synchrony
931     if (dt_elev_count < (3.0) + (rand() % 10))
932         return;
933     else
934        dt_elev_count = 0;
935
936     // Only do the proper hitlist stuff if we are within visible range of the viewer.
937     if (!invisible) {
938         double visibility_meters = fgGetDouble("/environment/visibility-m");
939
940         FGViewer* vw = globals->get_current_view();
941         double course, distance;
942
943         SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
944         SGWayPoint view (vw->getLongitude_deg(), vw->getLatitude_deg(), 0);
945         view.CourseAndDistance(current, &course, &distance);
946         if(distance > visibility_meters) {
947             //aip.getSGLocation()->set_cur_elev_m(aptElev);
948             return;
949         }
950
951         // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
952         double range = 500.0;
953         if (!globals->get_tile_mgr()->scenery_available(pos.getLatitudeDeg(), pos.getLongitudeDeg(), range)) {
954             // Try to shedule tiles for that position.
955             globals->get_tile_mgr()->update( aip.getSGLocation(), range );
956         }
957
958         // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
959         double alt;
960         if (globals->get_scenery()->get_elevation_m(pos.getLatitudeDeg(), pos.getLongitudeDeg(), 20000.0, alt, 0))
961             tgt_altitude_ft = alt * SG_METER_TO_FEET;
962
963         //cerr << "Target altitude : " << tgt_altitude_ft << endl;
964         // if (globals->get_scenery()->get_elevation_m(pos.lat(), pos.lon(),
965         //                                            20000.0, alt))
966         //    tgt_altitude_ft = alt * SG_METER_TO_FEET;
967         //cerr << "Target altitude : " << tgt_altitude_ft << endl;
968     }
969 }
970
971
972 void FGAIAircraft::setCallSign(const string& s) {
973     callsign = s;
974 }
975
976
977 void FGAIAircraft::setTACANChannelID(const string& id) {
978     TACAN_channel_id = id;
979 }
980
981
982 void FGAIAircraft::doGroundAltitude() {
983    if (fabs(altitude_ft - (tgt_altitude_ft+groundOffset)) > 1000.0)
984        altitude_ft = (tgt_altitude_ft + groundOffset);
985    else
986       altitude_ft += 0.1 * ((tgt_altitude_ft+groundOffset) - altitude_ft);
987 }
988
989
990 void FGAIAircraft::announcePositionToController() 
991 {
992   if (trafficRef) {
993     //FGTaxiRoute *taxiRoute = fp->getTaxiRoute();
994     
995     int leg = fp->getLeg();
996     
997     //if (fp->getCurrentWaypoint()->routeIndex != 0) {
998       //char buffer[10];
999       //snprintf (buffer, 10, "%d", node);
1000       // Note that leg was been incremented after creating the current leg, so we should use
1001       // leg numbers here that are one higher than the number that is used to create the leg
1002       //
1003       switch (leg) {
1004       case 3: // Taxiing to runway
1005         if (trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork()->exists())
1006           controller = trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork();
1007         break;
1008       case 4: //Take off tower controller
1009         if (trafficRef->getDepartureAirport()->getDynamics())
1010           {
1011             controller = trafficRef->getDepartureAirport()->getDynamics()->getTowerController();           
1012             //if (trafficRef->getDepartureAirport()->getId() == "EHAM") {
1013             //cerr << trafficRef->getCallSign() << " at runway " << fp->getRunway() << "Ready for departure "
1014             //   << trafficRef->getFlightType() << " to " << trafficRef->getArrivalAirport()->getId() << endl;
1015             //  if (controller == 0) {
1016             //cerr << "Error in assigning controller at " << trafficRef->getDepartureAirport()->getId() << endl;
1017                 //}
1018               
1019           } 
1020         else {
1021           cerr << "Error: Could not find Dynamics at airport : " << trafficRef->getDepartureAirport()->getId() << endl;
1022         }
1023         break;
1024       case 9: // Taxiing for parking
1025         if (trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork()->exists())
1026           controller = trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork();
1027         break;
1028       default: 
1029         controller = 0;
1030         break;
1031       }
1032       
1033     if ((controller != prevController) && (prevController != 0)) {
1034       prevController->signOff(getID());
1035       string callsign =  trafficRef->getCallSign();
1036       if ( trafficRef->getHeavy())
1037         callsign += "Heavy";
1038       switch (leg) {
1039       case 3:
1040         //cerr << callsign << " ready to taxi to runway " << fp->getRunway() << endl;
1041         break;
1042       case 4:
1043         //cerr << callsign << " at runway " << fp->getRunway() << "Ready for take-off. "
1044         //     << trafficRef->getFlightRules() << " to " << trafficRef->getArrivalAirport()->getId() 
1045         //     << "(" << trafficRef->getArrivalAirport()->getName() << ")."<< endl;
1046         break;
1047       }
1048     }
1049     prevController = controller;
1050     if (controller) {
1051       controller->announcePosition(getID(), fp, fp->getCurrentWaypoint()->routeIndex,
1052                            _getLatitude(), _getLongitude(), hdg, speed, altitude_ft, 
1053                                    trafficRef->getRadius(), leg, trafficRef->getCallSign());
1054     }
1055   }
1056 }
1057
1058
1059 void FGAIAircraft::processATC(FGATCInstruction instruction)
1060 {
1061   //cerr << "Processing ATC instruction (not Implimented yet)" << endl;
1062   if (instruction.getHoldPattern   ()) {
1063   }
1064   
1065   // Hold Position
1066   if (instruction.getHoldPosition  ()) {
1067     if (!holdPos) {
1068       //if (trafficRef)
1069       //cerr << trafficRef->getCallSign() << "Holding Position " << endl;
1070       holdPos = true;
1071     }
1072     AccelTo(0.0);
1073   } else {
1074     if (holdPos) {
1075       //if (trafficRef)
1076       //        cerr << trafficRef->getCallSign() << " Resuming Taxi " << endl;
1077       holdPos = false;
1078     }    
1079     // Change speed Instruction. This can only be excecuted when there is no 
1080     // Hold position instruction.
1081     if (instruction.getChangeSpeed   ()) {
1082       //  if (trafficRef)
1083       //cerr << trafficRef->getCallSign() << " Changing Speed " << endl;
1084       AccelTo(instruction.getSpeed());
1085     }else {
1086       if (fp) AccelTo(fp->getPreviousWaypoint()->speed);
1087     }
1088   }
1089   if (instruction.getChangeHeading ()) { 
1090     hdg_lock = false;
1091     TurnTo(instruction.getHeading());
1092   } else {
1093     if (fp) {hdg_lock = true;}
1094   }
1095   if (instruction.getChangeAltitude()) { 
1096   }
1097
1098 }