src/AIModel/AIAircraft.cxx

   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/route/waypoint.hxx>
  26 #include <Main/fg_props.hxx>
  27 #include <Main/globals.hxx>
  28 #include <Main/viewer.hxx>
  29 #include <Scenery/scenery.hxx>
  30 #include <Scenery/tilemgr.hxx>
  31 #include <Airports/dynamics.hxx>
  32 #include <Airports/simple.hxx>
  33
  34 #include <string>
  35 #include <math.h>
  36 #include <time.h>
  37
  38 #ifdef _MSC_VER
  39 #  include <float.h>
  40 #  define finite _finite
  41 #elif defined(__sun) || defined(sgi)
  42 #  include <ieeefp.h>
  43 #endif
  44
  45 using std::string;
  46
  47 #include "AIAircraft.hxx"
  48 #include "performancedata.hxx"
  49 #include "performancedb.hxx"
  50
  51 //#include <Airports/trafficcontroller.hxx>
  52
  53 static string tempReg;
  54
  55 FGAIAircraft::FGAIAircraft(FGAISchedule *ref) : FGAIBase(otAircraft) {
  56     trafficRef = ref;
  57     if (trafficRef) {
  58         groundOffset = trafficRef->getGroundOffset();
  59         setCallSign(trafficRef->getCallSign());
  60     }
  61     else
  62         groundOffset = 0;
  63
  64     fp = 0;
  65     controller = 0;
  66     prevController = 0;
  67     dt_count = 0;
  68     dt_elev_count = 0;
  69     use_perf_vs = true;
  70
  71     no_roll = false;
  72     tgt_speed = 0;
  73     speed = 0;
  74     groundTargetSpeed = 0;
  75
  76     // set heading and altitude locks
  77     hdg_lock = false;
  78     alt_lock = false;
  79     roll = 0;
  80     headingChangeRate = 0.0;
  81     headingError = 0;
  82     minBearing = 360;
  83     speedFraction =1.0;
  84
  85     holdPos = false;
  86     needsTaxiClearance = false;
  87     _needsGroundElevation = true;
  88
  89     _performance = 0; //TODO initialize to JET_TRANSPORT from PerformanceDB
  90     dt = 0;
  91 }
  92
  93
  94 FGAIAircraft::~FGAIAircraft() {
  95     //delete fp;
  96     if (controller)
  97         controller->signOff(getID());
  98 }
  99
 100
 101 void FGAIAircraft::readFromScenario(SGPropertyNode* scFileNode) {
 102     if (!scFileNode)
 103         return;
 104
 105     FGAIBase::readFromScenario(scFileNode);
 106
 107     setPerformance(scFileNode->getStringValue("class", "jet_transport"));
 108     setFlightPlan(scFileNode->getStringValue("flightplan"),
 109                   scFileNode->getBoolValue("repeat", false));
 110     setCallSign(scFileNode->getStringValue("callsign"));
 111 }
 112
 113
 114 void FGAIAircraft::bind() {
 115     FGAIBase::bind();
 116
 117     props->tie("controls/gear/gear-down",
 118                SGRawValueMethods<FGAIAircraft,bool>(*this,
 119                                                     &FGAIAircraft::_getGearDown));
 120     props->tie("transponder-id",
 121                SGRawValueMethods<FGAIAircraft,const char*>(*this,
 122                                                     &FGAIAircraft::_getTransponderCode));
 123 }
 124
 125
 126 void FGAIAircraft::unbind() {
 127     FGAIBase::unbind();
 128
 129     props->untie("controls/gear/gear-down");
 130     props->untie("transponder-id");
 131 }
 132
 133
 134 void FGAIAircraft::update(double dt) {
 135     FGAIBase::update(dt);
 136     Run(dt);
 137     Transform();
 138 }
 139
 140 void FGAIAircraft::setPerformance(const std::string& acclass) {
 141      static PerformanceDB perfdb; //TODO make it a global service
 142      setPerformance(perfdb.getDataFor(acclass));
 143   }
 144
 145
 146  void FGAIAircraft::setPerformance(PerformanceData *ps) {
 147      _performance = ps;
 148   }
 149
 150
 151  void FGAIAircraft::Run(double dt) {
 152       FGAIAircraft::dt = dt;
 153
 154      bool outOfSight = false,
 155         flightplanActive = true;
 156      updatePrimaryTargetValues(flightplanActive, outOfSight); // target hdg, alt, speed
 157      if (outOfSight) {
 158         return;
 159      }
 160
 161      if (!flightplanActive) {
 162         groundTargetSpeed = 0;
 163      }
 164
 165      handleATCRequests(); // ATC also has a word to say
 166      updateSecondaryTargetValues(); // target roll, vertical speed, pitch
 167      updateActualState();
 168      UpdateRadar(manager);
 169      checkVisibility();
 170   }
 171
 172 void FGAIAircraft::checkVisibility()
 173 {
 174   double visibility_meters = fgGetDouble("/environment/visibility-m");
 175   FGViewer* vw = globals->get_current_view();
 176   invisible = (SGGeodesy::distanceM(vw->getPosition(), pos) > visibility_meters);
 177 }
 178
 179
 180
 181 void FGAIAircraft::AccelTo(double speed) {
 182     tgt_speed = speed;
 183     if (!isStationary())
 184         _needsGroundElevation = true;
 185 }
 186
 187
 188 void FGAIAircraft::PitchTo(double angle) {
 189     tgt_pitch = angle;
 190     alt_lock = false;
 191 }
 192
 193
 194 void FGAIAircraft::RollTo(double angle) {
 195     tgt_roll = angle;
 196     hdg_lock = false;
 197 }
 198
 199
 200 void FGAIAircraft::YawTo(double angle) {
 201     tgt_yaw = angle;
 202 }
 203
 204
 205 void FGAIAircraft::ClimbTo(double alt_ft ) {
 206     tgt_altitude_ft = alt_ft;
 207     alt_lock = true;
 208 }
 209
 210
 211 void FGAIAircraft::TurnTo(double heading) {
 212     tgt_heading = heading;
 213     hdg_lock = true;
 214 }
 215
 216
 217 double FGAIAircraft::sign(double x) {
 218     if (x == 0.0)
 219         return x;
 220     else
 221         return x/fabs(x);
 222 }
 223
 224
 225 void FGAIAircraft::setFlightPlan(const std::string& flightplan, bool repeat) {
 226     if (!flightplan.empty()) {
 227         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
 228         fp->setRepeat(repeat);
 229         SetFlightPlan(fp);
 230     }
 231 }
 232
 233
 234 void FGAIAircraft::SetFlightPlan(FGAIFlightPlan *f) {
 235     delete fp;
 236     fp = f;
 237 }
 238
 239
 240 void FGAIAircraft::ProcessFlightPlan( double dt, time_t now ) {
 241
 242     // the one behind you
 243     FGAIFlightPlan::waypoint* prev = 0;
 244     // the one ahead
 245     FGAIFlightPlan::waypoint* curr = 0;
 246     // the next plus 1
 247     FGAIFlightPlan::waypoint* next = 0;
 248
 249     prev = fp->getPreviousWaypoint();
 250     curr = fp->getCurrentWaypoint();
 251     next = fp->getNextWaypoint();
 252
 253     dt_count += dt;
 254
 255     ///////////////////////////////////////////////////////////////////////////
 256     // Initialize the flightplan
 257     //////////////////////////////////////////////////////////////////////////
 258     if (!prev) {
 259         handleFirstWaypoint();
 260         return;
 261     }                            // end of initialization
 262     if (! fpExecutable(now))
 263           return;
 264     dt_count = 0;
 265
 266     double distanceToDescent;
 267     if(reachedEndOfCruise(distanceToDescent)) {
 268         if (!loadNextLeg(distanceToDescent)) {
 269             setDie(true);
 270             return;
 271         }
 272         prev = fp->getPreviousWaypoint();
 273         curr = fp->getCurrentWaypoint();
 274         next = fp->getNextWaypoint();
 275     }
 276     if (! leadPointReached(curr)) {
 277         controlHeading(curr);
 278         controlSpeed(curr, next);
 279     } else {
 280         if (curr->finished)      //end of the flight plan
 281         {
 282             if (fp->getRepeat())
 283                 fp->restart();
 284             else
 285                 setDie(true);
 286             return;
 287         }
 288
 289         if (next) {
 290             //TODO more intelligent method in AIFlightPlan, no need to send data it already has :-)
 291             tgt_heading = fp->getBearing(curr, next);
 292             spinCounter = 0;
 293         }
 294
 295         //TODO let the fp handle this (loading of next leg)
 296         fp->IncrementWaypoint( trafficRef != 0 );
 297         if  ( ((!(fp->getNextWaypoint()))) && (trafficRef != 0) )
 298             if (!loadNextLeg()) {
 299                 setDie(true);
 300                 return;
 301             }
 302
 303         prev = fp->getPreviousWaypoint();
 304         curr = fp->getCurrentWaypoint();
 305         next = fp->getNextWaypoint();
 306
 307         // Now that we have incremented the waypoints, excute some traffic manager specific code
 308         if (trafficRef) {
 309             //TODO isn't this best executed right at the beginning?
 310             if (! aiTrafficVisible()) {
 311                 setDie(true);
 312                 return;
 313             }
 314
 315             if (! handleAirportEndPoints(prev, now)) {
 316                 setDie(true);
 317                 return;
 318             }
 319
 320             announcePositionToController();
 321
 322         }
 323
 324         if (next) {
 325             fp->setLeadDistance(tgt_speed, tgt_heading, curr, next);
 326         }
 327
 328         if (!(prev->on_ground))  // only update the tgt altitude from flightplan if not on the ground
 329         {
 330             tgt_altitude_ft = prev->altitude;
 331             if (curr->crossat > -1000.0) {
 332                 use_perf_vs = false;
 333                 tgt_vs = (curr->crossat - altitude_ft) / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 334                          / 6076.0 / speed*60.0);
 335                 checkTcas();
 336                 tgt_altitude_ft = curr->crossat;
 337             } else {
 338                 use_perf_vs = true;
 339             }
 340         }
 341         AccelTo(prev->speed);
 342         hdg_lock = alt_lock = true;
 343         no_roll = prev->on_ground;
 344     }
 345 }
 346
 347 void FGAIAircraft::checkTcas(void)
 348 {
 349     if (props->getIntValue("tcas/threat-level",0)==3)
 350     {
 351         int RASense = props->getIntValue("tcas/ra-sense",0);
 352         if ((RASense>0)&&(tgt_vs<4000))
 353             // upward RA: climb!
 354             tgt_vs = 4000;
 355         else
 356         if (RASense<0)
 357         {
 358             // downward RA: descend!
 359             if (altitude_ft < 1000)
 360             {
 361                 // too low: level off
 362                 if (tgt_vs>0)
 363                     tgt_vs = 0;
 364             }
 365             else
 366             {
 367                 if (tgt_vs >- 4000)
 368                     tgt_vs = -4000;
 369             }
 370         }
 371     }
 372 }
 373
 374 void FGAIAircraft::initializeFlightPlan() {
 375 }
 376
 377
 378 bool FGAIAircraft::_getGearDown() const {
 379     return _performance->gearExtensible(this);
 380 }
 381
 382
 383 const char * FGAIAircraft::_getTransponderCode() const {
 384   return transponderCode.c_str();
 385 }
 386
 387
 388 bool FGAIAircraft::loadNextLeg(double distance) {
 389
 390     int leg;
 391     if ((leg = fp->getLeg())  == 10) {
 392         if (!trafficRef->next()) {
 393             return false;
 394         }
 395         setCallSign(trafficRef->getCallSign());
 396         leg = 1;
 397         fp->setLeg(leg);
 398     }
 399
 400     FGAirport *dep = trafficRef->getDepartureAirport();
 401     FGAirport *arr = trafficRef->getArrivalAirport();
 402     if (!(dep && arr)) {
 403         setDie(true);
 404
 405     } else {
 406         double cruiseAlt = trafficRef->getCruiseAlt() * 100;
 407
 408         fp->create (this,
 409                     dep,
 410                     arr,
 411                     leg,
 412                     cruiseAlt,
 413                     trafficRef->getSpeed(),
 414                     _getLatitude(),
 415                     _getLongitude(),
 416                     false,
 417                     trafficRef->getRadius(),
 418                     trafficRef->getFlightType(),
 419                     acType,
 420                     company,
 421                     distance);
 422        //cerr << "created  leg " << leg << " for " << trafficRef->getCallSign() << endl;
 423     }
 424     return true;
 425 }
 426
 427
 428 // Note: This code is copied from David Luff's AILocalTraffic
 429 // Warning - ground elev determination is CPU intensive
 430 // Either this function or the logic of how often it is called
 431 // will almost certainly change.
 432
 433 void FGAIAircraft::getGroundElev(double dt) {
 434     dt_elev_count += dt;
 435
 436     if (!needGroundElevation())
 437         return;
 438     // Update minimally every three secs, but add some randomness
 439     // to prevent all AI objects doing this in synchrony
 440     if (dt_elev_count < (3.0) + (rand() % 10))
 441         return;
 442
 443     dt_elev_count = 0;
 444
 445     // Only do the proper hitlist stuff if we are within visible range of the viewer.
 446     if (!invisible) {
 447         double visibility_meters = fgGetDouble("/environment/visibility-m");
 448         FGViewer* vw = globals->get_current_view();
 449
 450         if (SGGeodesy::distanceM(vw->getPosition(), pos) > visibility_meters) {
 451             return;
 452         }
 453
 454         double range = 500.0;
 455         if (globals->get_tile_mgr()->schedule_scenery(pos, range, 5.0))
 456         {
 457             double alt;
 458             if (getGroundElevationM(SGGeod::fromGeodM(pos, 20000), alt, 0))
 459             {
 460                 tgt_altitude_ft = alt * SG_METER_TO_FEET;
 461                 if (isStationary())
 462                 {
 463                     // aircraft is stationary and we obtained altitude for this spot - we're done.
 464                     _needsGroundElevation = false;
 465                 }
 466             }
 467         }
 468     }
 469 }
 470
 471
 472 void FGAIAircraft::doGroundAltitude() {
 473     if ((fabs(altitude_ft - (tgt_altitude_ft+groundOffset)) > 1000.0)||
 474         (isStationary()))
 475         altitude_ft = (tgt_altitude_ft + groundOffset);
 476     else
 477         altitude_ft += 0.1 * ((tgt_altitude_ft+groundOffset) - altitude_ft);
 478     tgt_vs = 0;
 479 }
 480
 481
 482 void FGAIAircraft::announcePositionToController() {
 483     if (trafficRef) {
 484         int leg = fp->getLeg();
 485
 486         // Note that leg has been incremented after creating the current leg, so we should use
 487         // leg numbers here that are one higher than the number that is used to create the leg
 488         //
 489         switch (leg) {
 490           case 2:              // Startup and Push back
 491             if (trafficRef->getDepartureAirport()->getDynamics())
 492                 controller = trafficRef->getDepartureAirport()->getDynamics()->getStartupController();
 493             break;
 494         case 3:              // Taxiing to runway
 495             if (trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork()->exists())
 496                 controller = trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork();
 497             break;
 498         case 4:              //Take off tower controller
 499             if (trafficRef->getDepartureAirport()->getDynamics()) {
 500                 controller = trafficRef->getDepartureAirport()->getDynamics()->getTowerController();
 501             } else {
 502                 cerr << "Error: Could not find Dynamics at airport : " << trafficRef->getDepartureAirport()->getId() << endl;
 503             }
 504             break;
 505         case 7:
 506              if (trafficRef->getDepartureAirport()->getDynamics()) {
 507                  controller = trafficRef->getArrivalAirport()->getDynamics()->getApproachController();
 508               }
 509               break;
 510         case 9:              // Taxiing for parking
 511             if (trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork()->exists())
 512                 controller = trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork();
 513             break;
 514         default:
 515             controller = 0;
 516             break;
 517         }
 518
 519         if ((controller != prevController) && (prevController != 0)) {
 520             prevController->signOff(getID());
 521         }
 522         prevController = controller;
 523         if (controller) {
 524             controller->announcePosition(getID(), fp, fp->getCurrentWaypoint()->routeIndex,
 525                                          _getLatitude(), _getLongitude(), hdg, speed, altitude_ft,
 526                                          trafficRef->getRadius(), leg, this);
 527         }
 528     }
 529 }
 530
 531 // Process ATC instructions and report back
 532
 533 void FGAIAircraft::processATC(FGATCInstruction instruction) {
 534     if (instruction.getCheckForCircularWait()) {
 535         // This is not exactly an elegant solution,
 536         // but at least it gives me a chance to check
 537         // if circular waits are resolved.
 538         // For now, just take the offending aircraft
 539         // out of the scene
 540         setDie(true);
 541         // a more proper way should be - of course - to
 542         // let an offending aircraft take an evasive action
 543         // for instance taxi back a little bit.
 544     }
 545     //cerr << "Processing ATC instruction (not Implimented yet)" << endl;
 546     if (instruction.getHoldPattern   ()) {}
 547
 548     // Hold Position
 549     if (instruction.getHoldPosition  ()) {
 550         if (!holdPos) {
 551             holdPos = true;
 552         }
 553         AccelTo(0.0);
 554     } else {
 555         if (holdPos) {
 556             //if (trafficRef)
 557             //  cerr << trafficRef->getCallSign() << " Resuming Taxi." << endl;
 558             holdPos = false;
 559         }
 560         // Change speed Instruction. This can only be excecuted when there is no
 561         // Hold position instruction.
 562         if (instruction.getChangeSpeed   ()) {
 563             //  if (trafficRef)
 564             //cerr << trafficRef->getCallSign() << " Changing Speed " << endl;
 565             AccelTo(instruction.getSpeed());
 566         } else {
 567             if (fp) AccelTo(fp->getPreviousWaypoint()->speed);
 568         }
 569     }
 570     if (instruction.getChangeHeading ()) {
 571         hdg_lock = false;
 572         TurnTo(instruction.getHeading());
 573     } else {
 574         if (fp) {
 575             hdg_lock = true;
 576         }
 577     }
 578     if (instruction.getChangeAltitude()) {}
 579
 580 }
 581
 582
 583 void FGAIAircraft::handleFirstWaypoint() {
 584     bool eraseWaypoints;         //TODO YAGNI
 585     headingError = 0;
 586     if (trafficRef) {
 587         eraseWaypoints = true;
 588     } else {
 589         eraseWaypoints = false;
 590     }
 591
 592     FGAIFlightPlan::waypoint* prev = 0; // the one behind you
 593     FGAIFlightPlan::waypoint* curr = 0; // the one ahead
 594     FGAIFlightPlan::waypoint* next = 0;// the next plus 1
 595
 596     spinCounter = 0;
 597     tempReg = "";
 598
 599     //TODO fp should handle this
 600     fp->IncrementWaypoint(eraseWaypoints);
 601     if (!(fp->getNextWaypoint()) && trafficRef)
 602         if (!loadNextLeg()) {
 603             setDie(true);
 604             return;
 605         }
 606
 607     prev = fp->getPreviousWaypoint();   //first waypoint
 608     curr = fp->getCurrentWaypoint();    //second waypoint
 609     next = fp->getNextWaypoint();       //third waypoint (might not exist!)
 610
 611     setLatitude(prev->latitude);
 612     setLongitude(prev->longitude);
 613     setSpeed(prev->speed);
 614     setAltitude(prev->altitude);
 615
 616     if (prev->speed > 0.0)
 617         setHeading(fp->getBearing(prev->latitude, prev->longitude, curr));
 618     else
 619         setHeading(fp->getBearing(curr->latitude, curr->longitude, prev));
 620
 621     // If next doesn't exist, as in incrementally created flightplans for
 622     // AI/Trafficmanager created plans,
 623     // Make sure lead distance is initialized otherwise
 624     if (next)
 625         fp->setLeadDistance(speed, hdg, curr, next);
 626
 627     if (curr->crossat > -1000.0) //use a calculated descent/climb rate
 628     {
 629         use_perf_vs = false;
 630         tgt_vs = (curr->crossat - prev->altitude)
 631                  / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 632                     / 6076.0 / prev->speed*60.0);
 633         checkTcas();
 634         tgt_altitude_ft = curr->crossat;
 635     } else {
 636         use_perf_vs = true;
 637         tgt_altitude_ft = prev->altitude;
 638     }
 639     alt_lock = hdg_lock = true;
 640     no_roll = prev->on_ground;
 641     if (no_roll) {
 642         Transform();             // make sure aip is initialized.
 643         getGroundElev(60.1);     // make sure it's executed first time around, so force a large dt value
 644         doGroundAltitude();
 645         _needsGroundElevation = true; // check ground elevation again (maybe scenery wasn't available yet)
 646     }
 647     // Make sure to announce the aircraft's position
 648     announcePositionToController();
 649     prevSpeed = 0;
 650 }
 651
 652
 653 /**
 654  * Check Execution time (currently once every 100 ms)
 655  * Add a bit of randomization to prevent the execution of all flight plans
 656  * in synchrony, which can add significant periodic framerate flutter.
 657  *
 658  * @param now
 659  * @return
 660  */
 661 bool FGAIAircraft::fpExecutable(time_t now) {
 662     double rand_exec_time = (rand() % 100) / 100;
 663     return (dt_count > (0.1+rand_exec_time)) && (fp->isActive(now));
 664 }
 665
 666
 667 /**
 668  * Check to see if we've reached the lead point for our next turn
 669  *
 670  * @param curr
 671  * @return
 672  */
 673 bool FGAIAircraft::leadPointReached(FGAIFlightPlan::waypoint* curr) {
 674     double dist_to_go = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 675
 676     //cerr << "2" << endl;
 677     double lead_dist = fp->getLeadDistance();
 678     // experimental: Use fabs, because speed can be negative (I hope) during push_back.
 679
 680     if (lead_dist < fabs(2*speed)) {
 681       //don't skip over the waypoint
 682       lead_dist = fabs(2*speed);
 683       //cerr << "Extending lead distance to " << lead_dist << endl;
 684     }
 685
 686     //prev_dist_to_go = dist_to_go;
 687     //if (dist_to_go < lead_dist)
 688     //     cerr << trafficRef->getCallSign() << " Distance : "
 689     //          << dist_to_go << ": Lead distance "
 690     //          << lead_dist << " " << curr->name
 691     //          << " Ground target speed " << groundTargetSpeed << endl;
 692     double bearing = 0;
 693     if (speed > 50) { // don't do bearing calculations for ground traffic
 694        bearing = getBearing(fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr));
 695        if (bearing < minBearing) {
 696             minBearing = bearing;
 697             if (minBearing < 10) {
 698                  minBearing = 10;
 699             }
 700             if ((minBearing < 360.0) && (minBearing > 10.0)) {
 701                 speedFraction = cos(minBearing *SG_DEGREES_TO_RADIANS);
 702             } else {
 703                 speedFraction = 1.0;
 704             }
 705        }
 706     }
 707     if (trafficRef) {
 708          //cerr << "Tracking callsign : \"" << fgGetString("/ai/track-callsign") << "\"" << endl;
 709 /*         if (trafficRef->getCallSign() == fgGetString("/ai/track-callsign")) {
 710               cerr << trafficRef->getCallSign() << " " << tgt_altitude_ft << " " << _getSpeed() << " "
 711                    << _getAltitude() << " "<< _getLatitude() << " " << _getLongitude() << " " << dist_to_go << " " << lead_dist << " " << curr->name << " " << vs << " " << tgt_vs << " " << bearing << " " << minBearing << " " << speedFraction << endl;
 712          }*/
 713      }
 714     if ((dist_to_go < lead_dist) || (bearing > (minBearing * 1.1))) {
 715         minBearing = 360;
 716         return true;
 717     } else {
 718         return false;
 719     }
 720 }
 721
 722
 723 bool FGAIAircraft::aiTrafficVisible() {
 724   SGGeod userPos(SGGeod::fromDeg(fgGetDouble("/position/longitude-deg"),
 725     fgGetDouble("/position/latitude-deg")));
 726
 727   return (SGGeodesy::distanceNm(userPos, pos) <= TRAFFICTOAIDISTTODIE);
 728 }
 729
 730
 731 /**
 732  * Handle release of parking gate, once were taxiing. Also ensure service time at the gate
 733  * in the case of an arrival.
 734  *
 735  * @param prev
 736  * @return
 737  */
 738
 739 //TODO the trafficRef is the right place for the method
 740 bool FGAIAircraft::handleAirportEndPoints(FGAIFlightPlan::waypoint* prev, time_t now) {
 741     // prepare routing from one airport to another
 742     FGAirport * dep = trafficRef->getDepartureAirport();
 743     FGAirport * arr = trafficRef->getArrivalAirport();
 744
 745     if (!( dep && arr))
 746         return false;
 747
 748     // This waypoint marks the fact that the aircraft has passed the initial taxi
 749     // departure waypoint, so it can release the parking.
 750     //cerr << trafficRef->getCallSign() << " has passed waypoint " << prev->name << " at speed " << speed << endl;
 751     if (prev->name == "PushBackPoint") {
 752         dep->getDynamics()->releaseParking(fp->getGate());
 753         AccelTo(0.0);
 754         setTaxiClearanceRequest(true);
 755     }
 756
 757     // This is the last taxi waypoint, and marks the the end of the flight plan
 758     // so, the schedule should update and wait for the next departure time.
 759     if (prev->name == "END") {
 760         time_t nextDeparture = trafficRef->getDepartureTime();
 761         // make sure to wait at least 20 minutes at parking to prevent "nervous" taxi behavior
 762         if (nextDeparture < (now+1200)) {
 763             nextDeparture = now + 1200;
 764         }
 765         fp->setTime(nextDeparture); // should be "next departure"
 766     }
 767
 768     return true;
 769 }
 770
 771
 772 /**
 773  * Check difference between target bearing and current heading and correct if necessary.
 774  *
 775  * @param curr
 776  */
 777 void FGAIAircraft::controlHeading(FGAIFlightPlan::waypoint* curr) {
 778     double calc_bearing = fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 779     //cerr << "Bearing = " << calc_bearing << endl;
 780     if (speed < 0) {
 781         calc_bearing +=180;
 782         if (calc_bearing > 360)
 783             calc_bearing -= 360;
 784     }
 785
 786     if (finite(calc_bearing)) {
 787         double hdg_error = calc_bearing - tgt_heading;
 788         if (fabs(hdg_error) > 0.01) {
 789             TurnTo( calc_bearing );
 790         }
 791
 792     } else {
 793         cerr << "calc_bearing is not a finite number : "
 794         << "Speed " << speed
 795         << "pos : " << pos.getLatitudeDeg() << ", " << pos.getLongitudeDeg()
 796         << "waypoint " << curr->latitude << ", " << curr->longitude << endl;
 797         cerr << "waypoint name " << curr->name;
 798         exit(1);                 // FIXME
 799     }
 800 }
 801
 802
 803 /**
 804  * Update the lead distance calculation if speed has changed sufficiently
 805  * to prevent spinning (hopefully);
 806  *
 807  * @param curr
 808  * @param next
 809  */
 810 void FGAIAircraft::controlSpeed(FGAIFlightPlan::waypoint* curr, FGAIFlightPlan::waypoint* next) {
 811     double speed_diff = speed - prevSpeed;
 812
 813     if (fabs(speed_diff) > 10) {
 814         prevSpeed = speed;
 815         if (next) {
 816             fp->setLeadDistance(speed, tgt_heading, curr, next);
 817         }
 818     }
 819 }
 820
 821
 822 /**
 823  * Update target values (heading, alt, speed) depending on flight plan or control properties
 824  */
 825 void FGAIAircraft::updatePrimaryTargetValues(bool& flightplanActive, bool& aiOutOfSight) {
 826     if (fp)                      // AI object has a flightplan
 827     {
 828         //TODO make this a function of AIBase
 829         time_t now = time(NULL) + fgGetLong("/sim/time/warp");
 830         //cerr << "UpateTArgetValues() " << endl;
 831         ProcessFlightPlan(dt, now);
 832
 833         // Do execute Ground elev for inactive aircraft, so they
 834         // Are repositioned to the correct ground altitude when the user flies within visibility range.
 835         // In addition, check whether we are out of user range, so this aircraft
 836         // can be deleted.
 837         if (onGround()) {
 838                 Transform();     // make sure aip is initialized.
 839                 getGroundElev(dt);
 840                 doGroundAltitude();
 841                 // Transform();
 842                 pos.setElevationFt(altitude_ft);
 843         }
 844         if (trafficRef) {
 845            //cerr << trafficRef->getRegistration() << " Setting altitude to " << altitude_ft;
 846             aiOutOfSight = !aiTrafficVisible();
 847             if (aiOutOfSight) {
 848                 setDie(true);
 849                 //cerr << trafficRef->getRegistration() << " is set to die " << endl;
 850                 aiOutOfSight = true;
 851                 return;
 852             }
 853         }
 854         timeElapsed = now - fp->getStartTime();
 855         flightplanActive = fp->isActive(now);
 856     } else {
 857         // no flight plan, update target heading, speed, and altitude
 858         // from control properties.  These default to the initial
 859         // settings in the config file, but can be changed "on the
 860         // fly".
 861         string lat_mode = props->getStringValue("controls/flight/lateral-mode");
 862         if ( lat_mode == "roll" ) {
 863             double angle
 864             = props->getDoubleValue("controls/flight/target-roll" );
 865             RollTo( angle );
 866         } else {
 867             double angle
 868             = props->getDoubleValue("controls/flight/target-hdg" );
 869             TurnTo( angle );
 870         }
 871
 872         string lon_mode
 873         = props->getStringValue("controls/flight/longitude-mode");
 874         if ( lon_mode == "alt" ) {
 875             double alt = props->getDoubleValue("controls/flight/target-alt" );
 876             ClimbTo( alt );
 877         } else {
 878             double angle
 879             = props->getDoubleValue("controls/flight/target-pitch" );
 880             PitchTo( angle );
 881         }
 882
 883         AccelTo( props->getDoubleValue("controls/flight/target-spd" ) );
 884     }
 885 }
 886
 887 void FGAIAircraft::updatePosition() {
 888     // convert speed to degrees per second
 889     double speed_north_deg_sec = cos( hdg * SGD_DEGREES_TO_RADIANS )
 890                                  * speed * 1.686 / ft_per_deg_lat;
 891     double speed_east_deg_sec  = sin( hdg * SGD_DEGREES_TO_RADIANS )
 892                                  * speed * 1.686 / ft_per_deg_lon;
 893
 894     // set new position
 895     pos.setLatitudeDeg( pos.getLatitudeDeg() + speed_north_deg_sec * dt);
 896     pos.setLongitudeDeg( pos.getLongitudeDeg() + speed_east_deg_sec * dt);
 897 }
 898
 899
 900 void FGAIAircraft::updateHeading() {
 901     // adjust heading based on current bank angle
 902     if (roll == 0.0)
 903         roll = 0.01;
 904
 905     if (roll != 0.0) {
 906         // double turnConstant;
 907         //if (no_roll)
 908         //  turnConstant = 0.0088362;
 909         //else
 910         //  turnConstant = 0.088362;
 911         // If on ground, calculate heading change directly
 912         if (onGround()) {
 913             double headingDiff = fabs(hdg-tgt_heading);
 914             double bank_sense = 0.0;
 915         /*
 916         double diff = fabs(hdg - tgt_heading);
 917         if (diff > 180)
 918             diff = fabs(diff - 360);
 919
 920         double sum = hdg + diff;
 921         if (sum > 360.0)
 922             sum -= 360.0;
 923         if (fabs(sum - tgt_heading) < 1.0) {
 924             bank_sense = 1.0;    // right turn
 925         } else {
 926             bank_sense = -1.0;   // left turn
 927         }*/
 928             if (headingDiff > 180)
 929                 headingDiff = fabs(headingDiff - 360);
 930             double sum = hdg + headingDiff;
 931             if (sum > 360.0)
 932                 sum -= 360.0;
 933             if (fabs(sum - tgt_heading) > 0.0001) {
 934                 bank_sense = -1.0;
 935             } else {
 936                 bank_sense = 1.0;
 937             }
 938             //if (trafficRef)
 939                 //cerr << trafficRef->getCallSign() << " Heading "
 940                 //     << hdg << ". Target " << tgt_heading <<  ". Diff " << fabs(sum - tgt_heading) << ". Speed " << speed << endl;
 941             //if (headingDiff > 60) {
 942             groundTargetSpeed = tgt_speed; // * cos(headingDiff * SG_DEGREES_TO_RADIANS);
 943                 //groundTargetSpeed = tgt_speed - tgt_speed * (headingDiff/180);
 944             //} else {
 945             //    groundTargetSpeed = tgt_speed;
 946             //}
 947             if (sign(groundTargetSpeed) != sign(tgt_speed))
 948                 groundTargetSpeed = 0.21 * sign(tgt_speed); // to prevent speed getting stuck in 'negative' mode
 949
 950             if (headingDiff > 30.0) {
 951                 // invert if pushed backward
 952                 headingChangeRate += 10.0 * dt * sign(roll);
 953
 954                 // Clamp the maximum steering rate to 30 degrees per second,
 955                 // But only do this when the heading error is decreasing.
 956                 if ((headingDiff < headingError)) {
 957                     if (headingChangeRate > 30)
 958                         headingChangeRate = 30;
 959                     else if (headingChangeRate < -30)
 960                         headingChangeRate = -30;
 961                 }
 962             } else {
 963                    if (fabs(headingChangeRate) > headingDiff)
 964                        headingChangeRate = headingDiff*sign(roll);
 965                    else
 966                        headingChangeRate += dt * sign(roll);
 967             }
 968
 969             hdg += headingChangeRate * dt * (fabs(speed) / 15);
 970             headingError = headingDiff;
 971         } else {
 972             if (fabs(speed) > 1.0) {
 973                 turn_radius_ft = 0.088362 * speed * speed
 974                                  / tan( fabs(roll) / SG_RADIANS_TO_DEGREES );
 975             } else {
 976                 // Check if turn_radius_ft == 0; this might lead to a division by 0.
 977                 turn_radius_ft = 1.0;
 978             }
 979             double turn_circum_ft = SGD_2PI * turn_radius_ft;
 980             double dist_covered_ft = speed * 1.686 * dt;
 981             double alpha = dist_covered_ft / turn_circum_ft * 360.0;
 982             hdg += alpha * sign(roll);
 983         }
 984         while ( hdg > 360.0 ) {
 985             hdg -= 360.0;
 986             spinCounter++;
 987         }
 988         while ( hdg < 0.0) {
 989             hdg += 360.0;
 990             spinCounter--;
 991         }
 992     }
 993 }
 994
 995
 996 void FGAIAircraft::updateBankAngleTarget() {
 997     // adjust target bank angle if heading lock engaged
 998     if (hdg_lock) {
 999         double bank_sense = 0.0;
1000         double diff = fabs(hdg - tgt_heading);
1001         if (diff > 180)
1002             diff = fabs(diff - 360);
1003
1004         double sum = hdg + diff;
1005         if (sum > 360.0)
1006             sum -= 360.0;
1007         if (fabs(sum - tgt_heading) < 1.0) {
1008             bank_sense = 1.0;    // right turn
1009         } else {
1010             bank_sense = -1.0;   // left turn
1011         }
1012         if (diff < _performance->maximumBankAngle()) {
1013             tgt_roll = diff * bank_sense;
1014         } else {
1015             tgt_roll = _performance->maximumBankAngle() * bank_sense;
1016         }
1017         if ((fabs((double) spinCounter) > 1) && (diff > _performance->maximumBankAngle())) {
1018             tgt_speed *= 0.999;  // Ugly hack: If aircraft get stuck, they will continually spin around.
1019             // The only way to resolve this is to make them slow down.
1020         }
1021     }
1022 }
1023
1024
1025 void FGAIAircraft::updateVerticalSpeedTarget() {
1026     // adjust target Altitude, based on ground elevation when on ground
1027     if (onGround()) {
1028         getGroundElev(dt);
1029         doGroundAltitude();
1030     } else if (alt_lock) {
1031         // find target vertical speed
1032         if (use_perf_vs) {
1033             if (altitude_ft < tgt_altitude_ft) {
1034                 tgt_vs = tgt_altitude_ft - altitude_ft;
1035                 if (tgt_vs > _performance->climbRate())
1036                     tgt_vs = _performance->climbRate();
1037             } else {
1038                 tgt_vs = tgt_altitude_ft - altitude_ft;
1039                 if (tgt_vs  < (-_performance->descentRate()))
1040                     tgt_vs = -_performance->descentRate();
1041             }
1042         } else {
1043             double max_vs = 4*(tgt_altitude_ft - altitude_ft);
1044             double min_vs = 100;
1045             if (tgt_altitude_ft < altitude_ft)
1046                 min_vs = -100.0;
1047             if ((fabs(tgt_altitude_ft - altitude_ft) < 1500.0)
1048                     && (fabs(max_vs) < fabs(tgt_vs)))
1049                 tgt_vs = max_vs;
1050
1051             if (fabs(tgt_vs) < fabs(min_vs))
1052                 tgt_vs = min_vs;
1053         }
1054     } //else
1055     //    tgt_vs = 0.0;
1056     checkTcas();
1057 }
1058
1059 void FGAIAircraft::updatePitchAngleTarget() {
1060     // if on ground and above vRotate -> initial rotation
1061     if (onGround() && (speed > _performance->vRotate()))
1062         tgt_pitch = 8.0; // some rough B737 value
1063
1064     //TODO pitch angle on approach and landing
1065
1066     // match pitch angle to vertical speed
1067     else if (tgt_vs > 0) {
1068         tgt_pitch = tgt_vs * 0.005;
1069     } else {
1070         tgt_pitch = tgt_vs * 0.002;
1071     }
1072 }
1073
1074 string FGAIAircraft::atGate() {
1075      string tmp("");
1076      if (fp->getLeg() < 3) {
1077          if (trafficRef) {
1078              if (fp->getGate() > 0) {
1079                  FGParking *park =
1080                      trafficRef->getDepartureAirport()->getDynamics()->getParking(fp->getGate());
1081                  tmp = park->getName();
1082              }
1083          }
1084      }
1085      return tmp;
1086 }
1087
1088 void FGAIAircraft::handleATCRequests() {
1089     //TODO implement NullController for having no ATC to save the conditionals
1090     if (controller) {
1091         controller->update(getID(),
1092                            pos.getLatitudeDeg(),
1093                            pos.getLongitudeDeg(),
1094                            hdg,
1095                            speed,
1096                            altitude_ft, dt);
1097         processATC(controller->getInstruction(getID()));
1098     }
1099 }
1100
1101 void FGAIAircraft::updateActualState() {
1102     //update current state
1103     //TODO have a single tgt_speed and check speed limit on ground on setting tgt_speed
1104     updatePosition();
1105
1106     if (onGround())
1107         speed = _performance->actualSpeed(this, groundTargetSpeed, dt);
1108     else
1109         speed = _performance->actualSpeed(this, (tgt_speed *speedFraction), dt);
1110
1111     updateHeading();
1112     roll = _performance->actualBankAngle(this, tgt_roll, dt);
1113
1114     // adjust altitude (meters) based on current vertical speed (fpm)
1115     altitude_ft += vs / 60.0 * dt;
1116     pos.setElevationFt(altitude_ft);
1117
1118     vs = _performance->actualVerticalSpeed(this, tgt_vs, dt);
1119     pitch = _performance->actualPitch(this, tgt_pitch, dt);
1120 }
1121
1122 void FGAIAircraft::updateSecondaryTargetValues() {
1123     // derived target state values
1124     updateBankAngleTarget();
1125     updateVerticalSpeedTarget();
1126     updatePitchAngleTarget();
1127
1128     //TODO calculate wind correction angle (tgt_yaw)
1129 }
1130
1131
1132 bool FGAIAircraft::reachedEndOfCruise(double &distance) {
1133     FGAIFlightPlan::waypoint* curr = fp->getCurrentWaypoint();
1134     if (curr->name == "BOD") {
1135         double dist = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
1136         double descentSpeed = (getPerformance()->vDescent() * SG_NM_TO_METER) / 3600.0;     // convert from kts to meter/s
1137         double descentRate  = (getPerformance()->descentRate() * SG_FEET_TO_METER) / 60.0;  // convert from feet/min to meter/s
1138
1139         double verticalDistance  = ((altitude_ft - 2000.0) - trafficRef->getArrivalAirport()->getElevation()) *SG_FEET_TO_METER;
1140         double descentTimeNeeded = verticalDistance / descentRate;
1141         double distanceCovered   = descentSpeed * descentTimeNeeded;
1142
1143         //cerr << "Tracking  : " << fgGetString("/ai/track-callsign");
1144         if (trafficRef->getCallSign() == fgGetString("/ai/track-callsign")) {
1145             cerr << "Checking for end of cruise stage for :" << trafficRef->getCallSign() << endl;
1146             cerr << "Descent rate      : " << descentRate << endl;
1147             cerr << "Descent speed     : " << descentSpeed << endl;
1148             cerr << "VerticalDistance  : " << verticalDistance << ". Altitude : " << altitude_ft << ". Elevation " << trafficRef->getArrivalAirport()->getElevation() << endl;
1149             cerr << "DecentTimeNeeded  : " << descentTimeNeeded << endl;
1150             cerr << "DistanceCovered   : " << distanceCovered   << endl;
1151         }
1152         //cerr << "Distance = " << distance << endl;
1153         distance = distanceCovered;
1154         if (dist < distanceCovered) {
1155               if (trafficRef->getCallSign() == fgGetString("/ai/track-callsign")) {
1156                    //exit(1);
1157               }
1158               return true;
1159         } else {
1160               return false;
1161         }
1162     } else {
1163          return false;
1164     }
1165 }
1166
1167 void FGAIAircraft::resetPositionFromFlightPlan()
1168 {
1169     // the one behind you
1170     FGAIFlightPlan::waypoint* prev = 0;
1171     // the one ahead
1172     FGAIFlightPlan::waypoint* curr = 0;
1173     // the next plus 1
1174     FGAIFlightPlan::waypoint* next = 0;
1175
1176     prev = fp->getPreviousWaypoint();
1177     curr = fp->getCurrentWaypoint();
1178     next = fp->getNextWaypoint();
1179
1180     setLatitude(prev->latitude);
1181     setLongitude(prev->longitude);
1182     double tgt_heading = fp->getBearing(curr, next);
1183     setHeading(tgt_heading);
1184     setAltitude(prev->altitude);
1185     setSpeed(prev->speed);
1186 }
1187
1188 double FGAIAircraft::getBearing(double crse)
1189 {
1190   double hdgDiff = fabs(hdg-crse);
1191   if (hdgDiff > 180)
1192       hdgDiff = fabs(hdgDiff - 360);
1193   return hdgDiff;
1194 }
1195
1196 time_t FGAIAircraft::checkForArrivalTime(string wptName) {
1197      FGAIFlightPlan::waypoint* curr = 0;
1198      curr = fp->getCurrentWaypoint();
1199
1200      double tracklength = fp->checkTrackLength(wptName);
1201      if (tracklength > 0.1) {
1202           tracklength += fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
1203      } else {
1204          return 0;
1205      }
1206      time_t now = time(NULL) + fgGetLong("/sim/time/warp");
1207      time_t arrivalTime = fp->getArrivalTime();
1208
1209      time_t ete = tracklength / ((speed * SG_NM_TO_METER) / 3600.0);
1210      time_t secondsToGo = arrivalTime - now;
1211      if (trafficRef->getCallSign() == fgGetString("/ai/track-callsign")) {
1212           cerr << "Checking arrival time: ete " << ete << ". Time to go : " << secondsToGo << ". Track length = " << tracklength << endl;
1213      }
1214      return (ete - secondsToGo); // Positive when we're too slow...
1215 }