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 #include <signal.h>
  51
  52 //#include <Airports/trafficcontroller.hxx>
  53
  54 FGAIAircraft::FGAIAircraft(FGAISchedule *ref) :
  55      /* HOT must be disabled for AI Aircraft,
  56       * otherwise traffic detection isn't working as expected.*/
  57      FGAIBase(otAircraft, false)
  58 {
  59     trafficRef = ref;
  60     if (trafficRef) {
  61         groundOffset = trafficRef->getGroundOffset();
  62         setCallSign(trafficRef->getCallSign());
  63     }
  64     else
  65         groundOffset = 0;
  66
  67     fp              = 0;
  68     controller      = 0;
  69     prevController  = 0;
  70     towerController = 0;
  71     dt_count = 0;
  72     dt_elev_count = 0;
  73     use_perf_vs = true;
  74
  75     no_roll = false;
  76     tgt_speed = 0;
  77     speed = 0;
  78     groundTargetSpeed = 0;
  79
  80     // set heading and altitude locks
  81     hdg_lock = false;
  82     alt_lock = false;
  83     roll = 0;
  84     headingChangeRate = 0.0;
  85     headingError = 0;
  86     minBearing = 360;
  87     speedFraction =1.0;
  88
  89     holdPos = false;
  90     needsTaxiClearance = false;
  91     _needsGroundElevation = true;
  92
  93     _performance = 0; //TODO initialize to JET_TRANSPORT from PerformanceDB
  94     dt = 0;
  95     takeOffStatus = 0;
  96 }
  97
  98
  99 FGAIAircraft::~FGAIAircraft() {
 100     //delete fp;
 101     if (controller)
 102         controller->signOff(getID());
 103 }
 104
 105
 106 void FGAIAircraft::readFromScenario(SGPropertyNode* scFileNode) {
 107     if (!scFileNode)
 108         return;
 109
 110     FGAIBase::readFromScenario(scFileNode);
 111
 112     setPerformance(scFileNode->getStringValue("class", "jet_transport"));
 113     setFlightPlan(scFileNode->getStringValue("flightplan"),
 114                   scFileNode->getBoolValue("repeat", false));
 115     setCallSign(scFileNode->getStringValue("callsign"));
 116 }
 117
 118
 119 void FGAIAircraft::bind() {
 120     FGAIBase::bind();
 121
 122     props->tie("controls/gear/gear-down",
 123                SGRawValueMethods<FGAIAircraft,bool>(*this,
 124                                                     &FGAIAircraft::_getGearDown));
 125     props->tie("transponder-id",
 126                SGRawValueMethods<FGAIAircraft,const char*>(*this,
 127                                                     &FGAIAircraft::_getTransponderCode));
 128 }
 129
 130
 131 void FGAIAircraft::unbind() {
 132     FGAIBase::unbind();
 133
 134     props->untie("controls/gear/gear-down");
 135     props->untie("transponder-id");
 136 }
 137
 138
 139 void FGAIAircraft::update(double dt) {
 140     FGAIBase::update(dt);
 141     Run(dt);
 142     Transform();
 143 }
 144
 145 void FGAIAircraft::setPerformance(const std::string& acclass) {
 146      static PerformanceDB perfdb; //TODO make it a global service
 147      setPerformance(perfdb.getDataFor(acclass));
 148   }
 149
 150
 151  void FGAIAircraft::setPerformance(PerformanceData *ps) {
 152      _performance = ps;
 153   }
 154
 155
 156  void FGAIAircraft::Run(double dt) {
 157       FGAIAircraft::dt = dt;
 158
 159      bool outOfSight = false,
 160         flightplanActive = true;
 161      updatePrimaryTargetValues(flightplanActive, outOfSight); // target hdg, alt, speed
 162      if (outOfSight) {
 163         return;
 164      }
 165
 166      if (!flightplanActive) {
 167         groundTargetSpeed = 0;
 168      }
 169
 170      handleATCRequests(); // ATC also has a word to say
 171      updateSecondaryTargetValues(); // target roll, vertical speed, pitch
 172      updateActualState();
 173     // We currently have one situation in which an AIAircraft object is used that is not attached to the
 174     // AI manager. In this particular case, the AIAircraft is used to shadow the user's aircraft's behavior in the AI world.
 175     // Since we perhaps don't want a radar entry of our own aircraft, the following conditional should probably be adequate
 176     // enough
 177      if (manager)
 178         UpdateRadar(manager);
 179      checkVisibility();
 180   }
 181
 182 void FGAIAircraft::checkVisibility()
 183 {
 184   double visibility_meters = fgGetDouble("/environment/visibility-m");
 185   FGViewer* vw = globals->get_current_view();
 186   invisible = (SGGeodesy::distanceM(vw->getPosition(), pos) > visibility_meters);
 187 }
 188
 189
 190
 191 void FGAIAircraft::AccelTo(double speed) {
 192     tgt_speed = speed;
 193     assertSpeed(speed);
 194     if (!isStationary())
 195         _needsGroundElevation = true;
 196 }
 197
 198
 199 void FGAIAircraft::PitchTo(double angle) {
 200     tgt_pitch = angle;
 201     alt_lock = false;
 202 }
 203
 204
 205 void FGAIAircraft::RollTo(double angle) {
 206     tgt_roll = angle;
 207     hdg_lock = false;
 208 }
 209
 210
 211 void FGAIAircraft::YawTo(double angle) {
 212     tgt_yaw = angle;
 213 }
 214
 215
 216 void FGAIAircraft::ClimbTo(double alt_ft ) {
 217     tgt_altitude_ft = alt_ft;
 218     alt_lock = true;
 219 }
 220
 221
 222 void FGAIAircraft::TurnTo(double heading) {
 223     tgt_heading = heading;
 224     hdg_lock = true;
 225 }
 226
 227
 228 double FGAIAircraft::sign(double x) {
 229     if (x == 0.0)
 230         return x;
 231     else
 232         return x/fabs(x);
 233 }
 234
 235
 236 void FGAIAircraft::setFlightPlan(const std::string& flightplan, bool repeat) {
 237     if (!flightplan.empty()) {
 238         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
 239         fp->setRepeat(repeat);
 240         SetFlightPlan(fp);
 241     }
 242 }
 243
 244
 245 void FGAIAircraft::SetFlightPlan(FGAIFlightPlan *f) {
 246     delete fp;
 247     fp = f;
 248 }
 249
 250
 251 void FGAIAircraft::ProcessFlightPlan( double dt, time_t now ) {
 252
 253     // the one behind you
 254     FGAIWaypoint* prev = 0;
 255     // the one ahead
 256     FGAIWaypoint* curr = 0;
 257     // the next plus 1
 258     FGAIWaypoint* next = 0;
 259
 260     prev = fp->getPreviousWaypoint();
 261     curr = fp->getCurrentWaypoint();
 262     next = fp->getNextWaypoint();
 263
 264     dt_count += dt;
 265
 266     ///////////////////////////////////////////////////////////////////////////
 267     // Initialize the flightplan
 268     //////////////////////////////////////////////////////////////////////////
 269     if (!prev) {
 270         handleFirstWaypoint();
 271         return;
 272     }                            // end of initialization
 273     if (! fpExecutable(now))
 274           return;
 275     dt_count = 0;
 276
 277     double distanceToDescent;
 278     if(reachedEndOfCruise(distanceToDescent)) {
 279         if (!loadNextLeg(distanceToDescent)) {
 280             setDie(true);
 281             return;
 282         }
 283         prev = fp->getPreviousWaypoint();
 284         curr = fp->getCurrentWaypoint();
 285         next = fp->getNextWaypoint();
 286     }
 287     if (! leadPointReached(curr)) {
 288         controlHeading(curr);
 289         controlSpeed(curr, next);
 290
 291             /*
 292             if (speed < 0) {
 293                 cerr << getCallSign()
 294                      << ": verifying lead distance to waypoint : "
 295                      << fp->getCurrentWaypoint()->name << " "
 296                      << fp->getLeadDistance() << ". Distance to go "
 297                      << (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr))
 298                      << ". Target speed = "
 299                      << tgt_speed
 300                      << ". Current speed = "
 301                      << speed
 302                      << ". Minimum Bearing " << minBearing
 303                      << endl;
 304             } */
 305     } else {
 306         if (curr->isFinished())      //end of the flight plan
 307         {
 308             if (fp->getRepeat())
 309                 fp->restart();
 310             else
 311                 setDie(true);
 312             return;
 313         }
 314
 315         if (next) {
 316             //TODO more intelligent method in AIFlightPlan, no need to send data it already has :-)
 317             tgt_heading = fp->getBearing(curr, next);
 318             spinCounter = 0;
 319         }
 320
 321         //TODO let the fp handle this (loading of next leg)
 322         fp->IncrementWaypoint( trafficRef != 0 );
 323         if  ( ((!(fp->getNextWaypoint()))) && (trafficRef != 0) )
 324             if (!loadNextLeg()) {
 325                 setDie(true);
 326                 return;
 327             }
 328
 329         prev = fp->getPreviousWaypoint();
 330         curr = fp->getCurrentWaypoint();
 331         next = fp->getNextWaypoint();
 332
 333         // Now that we have incremented the waypoints, excute some traffic manager specific code
 334         if (trafficRef) {
 335             //TODO isn't this best executed right at the beginning?
 336             if (! aiTrafficVisible()) {
 337                 setDie(true);
 338                 return;
 339             }
 340
 341             if (! handleAirportEndPoints(prev, now)) {
 342                 setDie(true);
 343                 return;
 344             }
 345
 346             announcePositionToController();
 347
 348         }
 349
 350         if (next) {
 351             fp->setLeadDistance(tgt_speed, tgt_heading, curr, next);
 352         }
 353
 354
 355         if (!(prev->getOn_ground()))  // only update the tgt altitude from flightplan if not on the ground
 356         {
 357             tgt_altitude_ft = prev->getAltitude();
 358             if (curr->getCrossat() > -1000.0) {
 359                 use_perf_vs = false;
 360                 // Distance to go in meters
 361                 double vert_dist_ft = curr->getCrossat() - altitude_ft;
 362                 double err_dist     = prev->getCrossat() - altitude_ft;
 363                 double dist_m       = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 364                 tgt_vs = calcVerticalSpeed(vert_dist_ft, dist_m, speed, err_dist);
 365
 366                 checkTcas();
 367                 tgt_altitude_ft = curr->getCrossat();
 368             } else {
 369                 use_perf_vs = true;
 370             }
 371         }
 372         AccelTo(prev->getSpeed());
 373         hdg_lock = alt_lock = true;
 374         no_roll = prev->getOn_ground();
 375     }
 376 }
 377
 378 double FGAIAircraft::calcVerticalSpeed(double vert_ft, double dist_m, double speed, double err)
 379 {
 380     // err is negative when we passed too high
 381     double vert_m = vert_ft * SG_FEET_TO_METER;
 382     double err_m  = err     * SG_FEET_TO_METER;
 383     //double angle = atan2(vert_m, dist_m);
 384     double speedMs = (speed * SG_NM_TO_METER) / 3600;
 385     //double vs = cos(angle) * speedMs; // Now in m/s
 386     double vs = 0;
 387     //cerr << "Error term = " << err_m << endl;
 388     if (dist_m) {
 389         vs = ((vert_m) / dist_m) * speedMs;
 390     }
 391     // Convert to feet per minute
 392     vs *= (SG_METER_TO_FEET * 60);
 393     //if (getCallSign() == "LUFTHANSA2002")
 394     //if (fabs(vs) > 100000) {
 395 //     if (getCallSign() == "LUFTHANSA2057") {
 396 //         cerr << getCallSign() << " " << fp->getPreviousWaypoint()->getName() << ". Alt = " << altitude_ft <<  " vertical dist = " << vert_m << " horiz dist = " << dist_m << " << angle  = " << angle * SG_RADIANS_TO_DEGREES << " vs " << vs << " horizontal speed " << speed << "Previous crossAT " << fp->getPreviousWaypoint()->getCrossat() << endl;
 397 //     //= (curr->getCrossat() - altitude_ft) / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 398 //     //                     / 6076.0 / speed*60.0);
 399 //         //raise(SIGSEGV);
 400 //     }
 401     return vs;
 402 }
 403
 404 void FGAIAircraft::assertSpeed(double speed)
 405 {
 406     if ((speed < -50) || (speed > 1000)) {
 407         cerr << getCallSign() << " "
 408             << "Previous waypoint " << fp->getPreviousWaypoint()->getName() << " "
 409             << "Departure airport " << trafficRef->getDepartureAirport() << " "
 410             << "Leg " << fp->getLeg() <<  " "
 411             << "target_speed << " << tgt_speed <<  " "
 412             << "speedFraction << " << speedFraction << " "
 413             << "Currecnt speed << " << speed << " "
 414             << endl;
 415        raise(SIGSEGV);
 416     }
 417 }
 418
 419
 420
 421 void FGAIAircraft::checkTcas(void)
 422 {
 423     if (props->getIntValue("tcas/threat-level",0)==3)
 424     {
 425         int RASense = props->getIntValue("tcas/ra-sense",0);
 426         if ((RASense>0)&&(tgt_vs<4000))
 427             // upward RA: climb!
 428             tgt_vs = 4000;
 429         else
 430         if (RASense<0)
 431         {
 432             // downward RA: descend!
 433             if (altitude_ft < 1000)
 434             {
 435                 // too low: level off
 436                 if (tgt_vs>0)
 437                     tgt_vs = 0;
 438             }
 439             else
 440             {
 441                 if (tgt_vs >- 4000)
 442                     tgt_vs = -4000;
 443             }
 444         }
 445     }
 446 }
 447
 448 void FGAIAircraft::initializeFlightPlan() {
 449 }
 450
 451
 452 bool FGAIAircraft::_getGearDown() const {
 453     return _performance->gearExtensible(this);
 454 }
 455
 456
 457 const char * FGAIAircraft::_getTransponderCode() const {
 458   return transponderCode.c_str();
 459 }
 460
 461 // NOTE: Check whether the new (delayed leg increment code has any effect on this code.
 462 // Probably not, because it should only be executed after we have already passed the leg incrementing waypoint.
 463
 464 bool FGAIAircraft::loadNextLeg(double distance) {
 465
 466     int leg;
 467     if ((leg = fp->getLeg())  == 9) {
 468         if (!trafficRef->next()) {
 469             return false;
 470         }
 471         setCallSign(trafficRef->getCallSign());
 472         leg = 0;
 473         fp->setLeg(leg);
 474     }
 475
 476     FGAirport *dep = trafficRef->getDepartureAirport();
 477     FGAirport *arr = trafficRef->getArrivalAirport();
 478     if (!(dep && arr)) {
 479         setDie(true);
 480
 481     } else {
 482         double cruiseAlt = trafficRef->getCruiseAlt() * 100;
 483
 484         fp->create (this,
 485                     dep,
 486                     arr,
 487                     leg+1,
 488                     cruiseAlt,
 489                     trafficRef->getSpeed(),
 490                     _getLatitude(),
 491                     _getLongitude(),
 492                     false,
 493                     trafficRef->getRadius(),
 494                     trafficRef->getFlightType(),
 495                     acType,
 496                     company,
 497                     distance);
 498        //cerr << "created  leg " << leg << " for " << trafficRef->getCallSign() << endl;
 499     }
 500     return true;
 501 }
 502
 503
 504 // Note: This code is copied from David Luff's AILocalTraffic
 505 // Warning - ground elev determination is CPU intensive
 506 // Either this function or the logic of how often it is called
 507 // will almost certainly change.
 508
 509 void FGAIAircraft::getGroundElev(double dt) {
 510     dt_elev_count += dt;
 511
 512     if (!needGroundElevation())
 513         return;
 514     // Update minimally every three secs, but add some randomness
 515     // to prevent all AI objects doing this in synchrony
 516     if (dt_elev_count < (3.0) + (rand() % 10))
 517         return;
 518
 519     dt_elev_count = 0;
 520
 521     // Only do the proper hitlist stuff if we are within visible range of the viewer.
 522     if (!invisible) {
 523         double visibility_meters = fgGetDouble("/environment/visibility-m");
 524         FGViewer* vw = globals->get_current_view();
 525
 526         if (SGGeodesy::distanceM(vw->getPosition(), pos) > visibility_meters) {
 527             return;
 528         }
 529
 530         double range = 500.0;
 531         if (globals->get_tile_mgr()->schedule_scenery(pos, range, 5.0))
 532         {
 533             double alt;
 534             if (getGroundElevationM(SGGeod::fromGeodM(pos, 20000), alt, 0))
 535             {
 536                 tgt_altitude_ft = alt * SG_METER_TO_FEET;
 537                 if (isStationary())
 538                 {
 539                     // aircraft is stationary and we obtained altitude for this spot - we're done.
 540                     _needsGroundElevation = false;
 541                 }
 542             }
 543         }
 544     }
 545 }
 546
 547
 548 void FGAIAircraft::doGroundAltitude() {
 549     if ((fp->getLeg() == 7) && ((altitude_ft -  tgt_altitude_ft) > 5)) {
 550         tgt_vs = -500;
 551     } else {
 552         if ((fabs(altitude_ft - (tgt_altitude_ft+groundOffset)) > 1000.0)||
 553             (isStationary()))
 554             altitude_ft = (tgt_altitude_ft + groundOffset);
 555         else
 556             altitude_ft += 0.1 * ((tgt_altitude_ft+groundOffset) - altitude_ft);
 557         tgt_vs = 0;
 558     }
 559 }
 560
 561
 562 void FGAIAircraft::announcePositionToController() {
 563     if (trafficRef) {
 564         int leg = fp->getLeg();
 565
 566         // Note that leg has been incremented after creating the current leg, so we should use
 567         // leg numbers here that are one higher than the number that is used to create the leg
 568         // NOTE: As of July, 30, 2011, the post-creation leg updating is no longer happening.
 569         // Leg numbers are updated only once the aircraft passes the last waypoint created for that legm so I should probably just use
 570         // the original leg numbers here!
 571         switch (leg) {
 572           case 1:              // Startup and Push back
 573             if (trafficRef->getDepartureAirport()->getDynamics())
 574                 controller = trafficRef->getDepartureAirport()->getDynamics()->getStartupController();
 575             break;
 576         case 2:              // Taxiing to runway
 577             if (trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork()->exists())
 578                 controller = trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork();
 579             break;
 580         case 3:              //Take off tower controller
 581             if (trafficRef->getDepartureAirport()->getDynamics()) {
 582                 controller = trafficRef->getDepartureAirport()->getDynamics()->getTowerController();
 583                 towerController = 0;
 584             } else {
 585                 cerr << "Error: Could not find Dynamics at airport : " << trafficRef->getDepartureAirport()->getId() << endl;
 586             }
 587             break;
 588         case 6:
 589              if (trafficRef->getDepartureAirport()->getDynamics()) {
 590                  controller = trafficRef->getArrivalAirport()->getDynamics()->getApproachController();
 591               }
 592               break;
 593         case 8:              // Taxiing for parking
 594             if (trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork()->exists())
 595                 controller = trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork();
 596             break;
 597         default:
 598             controller = 0;
 599             break;
 600         }
 601
 602         if ((controller != prevController) && (prevController != 0)) {
 603             prevController->signOff(getID());
 604         }
 605         prevController = controller;
 606         if (controller) {
 607             controller->announcePosition(getID(), fp, fp->getCurrentWaypoint()->getRouteIndex(),
 608                                          _getLatitude(), _getLongitude(), hdg, speed, altitude_ft,
 609                                          trafficRef->getRadius(), leg, this);
 610         }
 611     }
 612 }
 613
 614 void FGAIAircraft::scheduleForATCTowerDepartureControl(int state) {
 615     if (!takeOffStatus) {
 616         int leg = fp->getLeg();
 617         if (trafficRef) {
 618             if (trafficRef->getDepartureAirport()->getDynamics()) {
 619                 towerController = trafficRef->getDepartureAirport()->getDynamics()->getTowerController();
 620             } else {
 621                 cerr << "Error: Could not find Dynamics at airport : " << trafficRef->getDepartureAirport()->getId() << endl;
 622             }
 623             if (towerController) {
 624                 towerController->announcePosition(getID(), fp, fp->getCurrentWaypoint()->getRouteIndex(),
 625                                                    _getLatitude(), _getLongitude(), hdg, speed, altitude_ft,
 626                                                     trafficRef->getRadius(), leg, this);
 627                 //cerr << "Scheduling " << trafficRef->getCallSign() << " for takeoff " << endl;
 628             }
 629         }
 630     }
 631     takeOffStatus = state;
 632 }
 633
 634 // Process ATC instructions and report back
 635
 636 void FGAIAircraft::processATC(FGATCInstruction instruction) {
 637     if (instruction.getCheckForCircularWait()) {
 638         // This is not exactly an elegant solution,
 639         // but at least it gives me a chance to check
 640         // if circular waits are resolved.
 641         // For now, just take the offending aircraft
 642         // out of the scene
 643         setDie(true);
 644         // a more proper way should be - of course - to
 645         // let an offending aircraft take an evasive action
 646         // for instance taxi back a little bit.
 647     }
 648     //cerr << "Processing ATC instruction (not Implimented yet)" << endl;
 649     if (instruction.getHoldPattern   ()) {}
 650
 651     // Hold Position
 652     if (instruction.getHoldPosition  ()) {
 653         if (!holdPos) {
 654             holdPos = true;
 655         }
 656         AccelTo(0.0);
 657     } else {
 658         if (holdPos) {
 659             //if (trafficRef)
 660             //  cerr << trafficRef->getCallSign() << " Resuming Taxi." << endl;
 661             holdPos = false;
 662         }
 663         // Change speed Instruction. This can only be excecuted when there is no
 664         // Hold position instruction.
 665         if (instruction.getChangeSpeed   ()) {
 666             //  if (trafficRef)
 667             //cerr << trafficRef->getCallSign() << " Changing Speed " << endl;
 668             AccelTo(instruction.getSpeed());
 669         } else {
 670             if (fp) AccelTo(fp->getPreviousWaypoint()->getSpeed());
 671         }
 672     }
 673     if (instruction.getChangeHeading ()) {
 674         hdg_lock = false;
 675         TurnTo(instruction.getHeading());
 676     } else {
 677         if (fp) {
 678             hdg_lock = true;
 679         }
 680     }
 681     if (instruction.getChangeAltitude()) {}
 682
 683 }
 684
 685
 686 void FGAIAircraft::handleFirstWaypoint() {
 687     bool eraseWaypoints;         //TODO YAGNI
 688     headingError = 0;
 689     if (trafficRef) {
 690         eraseWaypoints = true;
 691     } else {
 692         eraseWaypoints = false;
 693     }
 694
 695     FGAIWaypoint* prev = 0; // the one behind you
 696     FGAIWaypoint* curr = 0; // the one ahead
 697     FGAIWaypoint* next = 0;// the next plus 1
 698
 699     spinCounter = 0;
 700
 701     //TODO fp should handle this
 702     fp->IncrementWaypoint(eraseWaypoints);
 703     if (!(fp->getNextWaypoint()) && trafficRef)
 704         if (!loadNextLeg()) {
 705             setDie(true);
 706             return;
 707         }
 708
 709     prev = fp->getPreviousWaypoint();   //first waypoint
 710     curr = fp->getCurrentWaypoint();    //second waypoint
 711     next = fp->getNextWaypoint();       //third waypoint (might not exist!)
 712
 713     setLatitude(prev->getLatitude());
 714     setLongitude(prev->getLongitude());
 715     setSpeed(prev->getSpeed());
 716     setAltitude(prev->getAltitude());
 717
 718     if (prev->getSpeed() > 0.0)
 719         setHeading(fp->getBearing(prev->getLatitude(), prev->getLongitude(), curr));
 720     else
 721         setHeading(fp->getBearing(curr->getLatitude(), curr->getLongitude(), prev));
 722
 723     // If next doesn't exist, as in incrementally created flightplans for
 724     // AI/Trafficmanager created plans,
 725     // Make sure lead distance is initialized otherwise
 726     if (next)
 727         fp->setLeadDistance(speed, hdg, curr, next);
 728
 729     if (curr->getCrossat() > -1000.0) //use a calculated descent/climb rate
 730     {
 731         use_perf_vs = false;
 732         //tgt_vs = (curr->getCrossat() - prev->getAltitude())
 733         //         / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 734         //            / 6076.0 / prev->getSpeed()*60.0);
 735         double vert_dist_ft = curr->getCrossat() - altitude_ft;
 736         double err_dist     = prev->getCrossat() - altitude_ft;
 737         double dist_m       = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 738         tgt_vs = calcVerticalSpeed(vert_dist_ft, dist_m, speed, err_dist);
 739         checkTcas();
 740         tgt_altitude_ft = curr->getCrossat();
 741     } else {
 742         use_perf_vs = true;
 743         tgt_altitude_ft = prev->getAltitude();
 744     }
 745     alt_lock = hdg_lock = true;
 746     no_roll = prev->getOn_ground();
 747     if (no_roll) {
 748         Transform();             // make sure aip is initialized.
 749         getGroundElev(60.1);     // make sure it's executed first time around, so force a large dt value
 750         doGroundAltitude();
 751         _needsGroundElevation = true; // check ground elevation again (maybe scenery wasn't available yet)
 752     }
 753     // Make sure to announce the aircraft's position
 754     announcePositionToController();
 755     prevSpeed = 0;
 756 }
 757
 758
 759 /**
 760  * Check Execution time (currently once every 100 ms)
 761  * Add a bit of randomization to prevent the execution of all flight plans
 762  * in synchrony, which can add significant periodic framerate flutter.
 763  *
 764  * @param now
 765  * @return
 766  */
 767 bool FGAIAircraft::fpExecutable(time_t now) {
 768     double rand_exec_time = (rand() % 100) / 100;
 769     return (dt_count > (0.1+rand_exec_time)) && (fp->isActive(now));
 770 }
 771
 772
 773 /**
 774  * Check to see if we've reached the lead point for our next turn
 775  *
 776  * @param curr
 777  * @return
 778  */
 779 bool FGAIAircraft::leadPointReached(FGAIWaypoint* curr) {
 780     double dist_to_go = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 781
 782     //cerr << "2" << endl;
 783     double lead_dist = fp->getLeadDistance();
 784     // experimental: Use fabs, because speed can be negative (I hope) during push_back.
 785     if ((dist_to_go < fabs(10.0* speed)) && (speed < 0) && (tgt_speed < 0) && fp->getCurrentWaypoint()->contains("PushBackPoint")) {
 786           tgt_speed = -(dist_to_go / 10.0);
 787           if (tgt_speed > -0.5) {
 788                 tgt_speed = -0.5;
 789           }
 790           assertSpeed(tgt_speed);
 791           if (fp->getPreviousWaypoint()->getSpeed() < tgt_speed) {
 792               fp->getPreviousWaypoint()->setSpeed(tgt_speed);
 793           }
 794     }
 795     if (lead_dist < fabs(2*speed)) {
 796       //don't skip over the waypoint
 797       lead_dist = fabs(2*speed);
 798       //cerr << "Extending lead distance to " << lead_dist << endl;
 799     }
 800
 801     //prev_dist_to_go = dist_to_go;
 802     //if (dist_to_go < lead_dist)
 803     //     cerr << trafficRef->getCallSign() << " Distance : "
 804     //          << dist_to_go << ": Lead distance "
 805     //          << lead_dist << " " << curr->name
 806     //          << " Ground target speed " << groundTargetSpeed << endl;
 807     double bearing = 0;
 808     if (speed > 50) { // don't do bearing calculations for ground traffic
 809        bearing = getBearing(fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr));
 810        if (bearing < minBearing) {
 811             minBearing = bearing;
 812             if (minBearing < 10) {
 813                  minBearing = 10;
 814             }
 815             if ((minBearing < 360.0) && (minBearing > 10.0)) {
 816                 speedFraction = 0.5 + (cos(minBearing *SG_DEGREES_TO_RADIANS) * 0.5);
 817             } else {
 818                 speedFraction = 1.0;
 819             }
 820        }
 821     }
 822     if (trafficRef) {
 823          //cerr << "Tracking callsign : \"" << fgGetString("/ai/track-callsign") << "\"" << endl;
 824 /*         if (trafficRef->getCallSign() == fgGetString("/ai/track-callsign")) {
 825               cerr << trafficRef->getCallSign() << " " << tgt_altitude_ft << " " << _getSpeed() << " "
 826                    << _getAltitude() << " "<< _getLatitude() << " " << _getLongitude() << " " << dist_to_go << " " << lead_dist << " " << curr->name << " " << vs << " " << tgt_vs << " " << bearing << " " << minBearing << " " << speedFraction << endl;
 827          }*/
 828      }
 829     if ((dist_to_go < lead_dist) || (bearing > (minBearing * 1.1))) {
 830         minBearing = 360;
 831         speedFraction = 1.0;
 832         return true;
 833     } else {
 834         return false;
 835     }
 836 }
 837
 838
 839 bool FGAIAircraft::aiTrafficVisible() {
 840   SGGeod userPos(SGGeod::fromDeg(fgGetDouble("/position/longitude-deg"),
 841     fgGetDouble("/position/latitude-deg")));
 842
 843   return (SGGeodesy::distanceNm(userPos, pos) <= TRAFFICTOAIDISTTODIE);
 844 }
 845
 846
 847 /**
 848  * Handle release of parking gate, once were taxiing. Also ensure service time at the gate
 849  * in the case of an arrival.
 850  *
 851  * @param prev
 852  * @return
 853  */
 854
 855 //TODO the trafficRef is the right place for the method
 856 bool FGAIAircraft::handleAirportEndPoints(FGAIWaypoint* prev, time_t now) {
 857     // prepare routing from one airport to another
 858     FGAirport * dep = trafficRef->getDepartureAirport();
 859     FGAirport * arr = trafficRef->getArrivalAirport();
 860
 861     if (!( dep && arr))
 862         return false;
 863
 864     // This waypoint marks the fact that the aircraft has passed the initial taxi
 865     // departure waypoint, so it can release the parking.
 866     //cerr << trafficRef->getCallSign() << " has passed waypoint " << prev->name << " at speed " << speed << endl;
 867     //cerr << "Passing waypoint : " << prev->getName() << endl;
 868     if (prev->contains("PushBackPoint")) {
 869         dep->getDynamics()->releaseParking(fp->getGate());
 870         AccelTo(0.0);
 871         //setTaxiClearanceRequest(true);
 872     }
 873     if (prev->contains("legend")) {
 874         fp->incrementLeg();
 875     }
 876     if (prev->contains(string("DepartureHold"))) {
 877         //cerr << "Passing point DepartureHold" << endl;
 878         scheduleForATCTowerDepartureControl(1);
 879     }
 880     if (prev->contains(string("Accel"))) {
 881         takeOffStatus = 3;
 882     }
 883     /*if (prev->contains(string("final"))) {
 884
 885          cerr << getCallSign() << " "
 886             << fp->getPreviousWaypoint()->getName()
 887             << ". Alt = " << altitude_ft
 888             << " vs " << vs
 889             << " horizontal speed " << speed
 890             << "Previous crossAT " << fp->getPreviousWaypoint()->getCrossat()
 891             << "Airport elevation" << getTrafficRef()->getArrivalAirport()->getElevation()
 892             << "Altitude difference " << (altitude_ft -  fp->getPreviousWaypoint()->getCrossat()) << endl;
 893     }*/
 894     // This is the last taxi waypoint, and marks the the end of the flight plan
 895     // so, the schedule should update and wait for the next departure time.
 896     if (prev->contains("END")) {
 897         time_t nextDeparture = trafficRef->getDepartureTime();
 898         // make sure to wait at least 20 minutes at parking to prevent "nervous" taxi behavior
 899         if (nextDeparture < (now+1200)) {
 900             nextDeparture = now + 1200;
 901         }
 902         fp->setTime(nextDeparture);
 903     }
 904
 905     return true;
 906 }
 907
 908
 909 /**
 910  * Check difference between target bearing and current heading and correct if necessary.
 911  *
 912  * @param curr
 913  */
 914 void FGAIAircraft::controlHeading(FGAIWaypoint* curr) {
 915     double calc_bearing = fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 916     //cerr << "Bearing = " << calc_bearing << endl;
 917     if (speed < 0) {
 918         calc_bearing +=180;
 919         if (calc_bearing > 360)
 920             calc_bearing -= 360;
 921     }
 922
 923     if (finite(calc_bearing)) {
 924         double hdg_error = calc_bearing - tgt_heading;
 925         if (fabs(hdg_error) > 0.01) {
 926             TurnTo( calc_bearing );
 927         }
 928
 929     } else {
 930         cerr << "calc_bearing is not a finite number : "
 931         << "Speed " << speed
 932         << "pos : " << pos.getLatitudeDeg() << ", " << pos.getLongitudeDeg()
 933         << "waypoint " << curr->getLatitude() << ", " << curr->getLongitude() << endl;
 934         cerr << "waypoint name " << curr->getName();
 935         exit(1);                 // FIXME
 936     }
 937 }
 938
 939
 940 /**
 941  * Update the lead distance calculation if speed has changed sufficiently
 942  * to prevent spinning (hopefully);
 943  *
 944  * @param curr
 945  * @param next
 946  */
 947 void FGAIAircraft::controlSpeed(FGAIWaypoint* curr, FGAIWaypoint* next) {
 948     double speed_diff = speed - prevSpeed;
 949
 950     if (fabs(speed_diff) > 10) {
 951         prevSpeed = speed;
 952         assertSpeed(speed);
 953         if (next) {
 954             fp->setLeadDistance(speed, tgt_heading, curr, next);
 955         }
 956     }
 957 }
 958
 959
 960 /**
 961  * Update target values (heading, alt, speed) depending on flight plan or control properties
 962  */
 963 void FGAIAircraft::updatePrimaryTargetValues(bool& flightplanActive, bool& aiOutOfSight) {
 964     if (fp)                      // AI object has a flightplan
 965     {
 966         //TODO make this a function of AIBase
 967         time_t now = time(NULL) + fgGetLong("/sim/time/warp");
 968         //cerr << "UpateTArgetValues() " << endl;
 969         ProcessFlightPlan(dt, now);
 970
 971         // Do execute Ground elev for inactive aircraft, so they
 972         // Are repositioned to the correct ground altitude when the user flies within visibility range.
 973         // In addition, check whether we are out of user range, so this aircraft
 974         // can be deleted.
 975         if (onGround()) {
 976                 Transform();     // make sure aip is initialized.
 977                 getGroundElev(dt);
 978                 doGroundAltitude();
 979                 // Transform();
 980                 pos.setElevationFt(altitude_ft);
 981         }
 982         if (trafficRef) {
 983            //cerr << trafficRef->getRegistration() << " Setting altitude to " << altitude_ft;
 984             aiOutOfSight = !aiTrafficVisible();
 985             if (aiOutOfSight) {
 986                 setDie(true);
 987                 //cerr << trafficRef->getRegistration() << " is set to die " << endl;
 988                 aiOutOfSight = true;
 989                 return;
 990             }
 991         }
 992         timeElapsed = now - fp->getStartTime();
 993         flightplanActive = fp->isActive(now);
 994     } else {
 995         // no flight plan, update target heading, speed, and altitude
 996         // from control properties.  These default to the initial
 997         // settings in the config file, but can be changed "on the
 998         // fly".
 999         string lat_mode = props->getStringValue("controls/flight/lateral-mode");
1000         if ( lat_mode == "roll" ) {
1001             double angle
1002             = props->getDoubleValue("controls/flight/target-roll" );
1003             RollTo( angle );
1004         } else {
1005             double angle
1006             = props->getDoubleValue("controls/flight/target-hdg" );
1007             TurnTo( angle );
1008         }
1009
1010         string lon_mode
1011         = props->getStringValue("controls/flight/longitude-mode");
1012         if ( lon_mode == "alt" ) {
1013             double alt = props->getDoubleValue("controls/flight/target-alt" );
1014             ClimbTo( alt );
1015         } else {
1016             double angle
1017             = props->getDoubleValue("controls/flight/target-pitch" );
1018             PitchTo( angle );
1019         }
1020
1021         AccelTo( props->getDoubleValue("controls/flight/target-spd" ) );
1022     }
1023 }
1024
1025 void FGAIAircraft::updatePosition() {
1026     // convert speed to degrees per second
1027     double speed_north_deg_sec = cos( hdg * SGD_DEGREES_TO_RADIANS )
1028                                  * speed * 1.686 / ft_per_deg_lat;
1029     double speed_east_deg_sec  = sin( hdg * SGD_DEGREES_TO_RADIANS )
1030                                  * speed * 1.686 / ft_per_deg_lon;
1031
1032     // set new position
1033     pos.setLatitudeDeg( pos.getLatitudeDeg() + speed_north_deg_sec * dt);
1034     pos.setLongitudeDeg( pos.getLongitudeDeg() + speed_east_deg_sec * dt);
1035 }
1036
1037
1038 void FGAIAircraft::updateHeading() {
1039     // adjust heading based on current bank angle
1040     if (roll == 0.0)
1041         roll = 0.01;
1042
1043     if (roll != 0.0) {
1044         // double turnConstant;
1045         //if (no_roll)
1046         //  turnConstant = 0.0088362;
1047         //else
1048         //  turnConstant = 0.088362;
1049         // If on ground, calculate heading change directly
1050         if (onGround()) {
1051             double headingDiff = fabs(hdg-tgt_heading);
1052             double bank_sense = 0.0;
1053         /*
1054         double diff = fabs(hdg - tgt_heading);
1055         if (diff > 180)
1056             diff = fabs(diff - 360);
1057
1058         double sum = hdg + diff;
1059         if (sum > 360.0)
1060             sum -= 360.0;
1061         if (fabs(sum - tgt_heading) < 1.0) {
1062             bank_sense = 1.0;    // right turn
1063         } else {
1064             bank_sense = -1.0;   // left turn
1065         }*/
1066             if (headingDiff > 180)
1067                 headingDiff = fabs(headingDiff - 360);
1068             double sum = hdg + headingDiff;
1069             if (sum > 360.0)
1070                 sum -= 360.0;
1071             if (fabs(sum - tgt_heading) > 0.0001) {
1072                 bank_sense = -1.0;
1073             } else {
1074                 bank_sense = 1.0;
1075             }
1076             //if (trafficRef)
1077             //  cerr << trafficRef->getCallSign() << " Heading "
1078             //         << hdg << ". Target " << tgt_heading <<  ". Diff " << fabs(sum - tgt_heading) << ". Speed " << speed << endl;
1079             //if (headingDiff > 60) {
1080             groundTargetSpeed = tgt_speed; // * cos(headingDiff * SG_DEGREES_TO_RADIANS);
1081             assertSpeed(groundTargetSpeed);
1082                 //groundTargetSpeed = tgt_speed - tgt_speed * (headingDiff/180);
1083             //} else {
1084             //    groundTargetSpeed = tgt_speed;
1085             //}
1086             if (sign(groundTargetSpeed) != sign(tgt_speed))
1087                 groundTargetSpeed = 0.21 * sign(tgt_speed); // to prevent speed getting stuck in 'negative' mode
1088             assertSpeed(groundTargetSpeed);
1089             // Only update the target values when we're not moving because otherwise we might introduce an enormous target change rate while waiting a the gate, or holding.
1090             if (speed != 0) {
1091                 if (headingDiff > 30.0) {
1092                     // invert if pushed backward
1093                     headingChangeRate += 10.0 * dt * sign(roll);
1094
1095                     // Clamp the maximum steering rate to 30 degrees per second,
1096                     // But only do this when the heading error is decreasing.
1097                     if ((headingDiff < headingError)) {
1098                         if (headingChangeRate > 30)
1099                             headingChangeRate = 30;
1100                         else if (headingChangeRate < -30)
1101                             headingChangeRate = -30;
1102                     }
1103                 } else {
1104                     if (speed != 0) {
1105                         if (fabs(headingChangeRate) > headingDiff)
1106                             headingChangeRate = headingDiff*sign(roll);
1107                         else
1108                             headingChangeRate += dt * sign(roll);
1109                     }
1110                 }
1111             }
1112             if (trafficRef)
1113                 //cerr << trafficRef->getCallSign() << " Heading "
1114                 //     << hdg << ". Target " << tgt_heading <<  ". Diff " << fabs(sum - tgt_heading) << ". Speed " << speed << "Heading change rate : " << headingChangeRate << " bacnk sence " << bank_sense << endl;
1115             hdg += headingChangeRate * dt * sqrt(fabs(speed) / 15);
1116             headingError = headingDiff;
1117         } else {
1118             if (fabs(speed) > 1.0) {
1119                 turn_radius_ft = 0.088362 * speed * speed
1120                                  / tan( fabs(roll) / SG_RADIANS_TO_DEGREES );
1121             } else {
1122                 // Check if turn_radius_ft == 0; this might lead to a division by 0.
1123                 turn_radius_ft = 1.0;
1124             }
1125             double turn_circum_ft = SGD_2PI * turn_radius_ft;
1126             double dist_covered_ft = speed * 1.686 * dt;
1127             double alpha = dist_covered_ft / turn_circum_ft * 360.0;
1128             hdg += alpha * sign(roll);
1129         }
1130         while ( hdg > 360.0 ) {
1131             hdg -= 360.0;
1132             spinCounter++;
1133         }
1134         while ( hdg < 0.0) {
1135             hdg += 360.0;
1136             spinCounter--;
1137         }
1138     }
1139 }
1140
1141
1142 void FGAIAircraft::updateBankAngleTarget() {
1143     // adjust target bank angle if heading lock engaged
1144     if (hdg_lock) {
1145         double bank_sense = 0.0;
1146         double diff = fabs(hdg - tgt_heading);
1147         if (diff > 180)
1148             diff = fabs(diff - 360);
1149
1150         double sum = hdg + diff;
1151         if (sum > 360.0)
1152             sum -= 360.0;
1153         if (fabs(sum - tgt_heading) < 1.0) {
1154             bank_sense = 1.0;    // right turn
1155         } else {
1156             bank_sense = -1.0;   // left turn
1157         }
1158         if (diff < _performance->maximumBankAngle()) {
1159             tgt_roll = diff * bank_sense;
1160         } else {
1161             tgt_roll = _performance->maximumBankAngle() * bank_sense;
1162         }
1163         if ((fabs((double) spinCounter) > 1) && (diff > _performance->maximumBankAngle())) {
1164             tgt_speed *= 0.999;  // Ugly hack: If aircraft get stuck, they will continually spin around.
1165             // The only way to resolve this is to make them slow down.
1166         }
1167     }
1168 }
1169
1170
1171 void FGAIAircraft::updateVerticalSpeedTarget() {
1172     // adjust target Altitude, based on ground elevation when on ground
1173     if (onGround()) {
1174         getGroundElev(dt);
1175         doGroundAltitude();
1176     } else if (alt_lock) {
1177         // find target vertical speed
1178         if (use_perf_vs) {
1179             if (altitude_ft < tgt_altitude_ft) {
1180                 tgt_vs = tgt_altitude_ft - altitude_ft;
1181                 if (tgt_vs > _performance->climbRate())
1182                     tgt_vs = _performance->climbRate();
1183             } else {
1184                 tgt_vs = tgt_altitude_ft - altitude_ft;
1185                 if (tgt_vs  < (-_performance->descentRate()))
1186                     tgt_vs = -_performance->descentRate();
1187             }
1188         } else {
1189             double vert_dist_ft = fp->getCurrentWaypoint()->getCrossat() - altitude_ft;
1190             double err_dist     = 0; //prev->getCrossat() - altitude_ft;
1191             double dist_m       = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), fp->getCurrentWaypoint());
1192             tgt_vs = calcVerticalSpeed(vert_dist_ft, dist_m, speed, err_dist);
1193             //cerr << "Target vs before : " << tgt_vs;
1194 /*            double max_vs = 10*(tgt_altitude_ft - altitude_ft);
1195             double min_vs = 100;
1196             if (tgt_altitude_ft < altitude_ft)
1197                 min_vs = -100.0;
1198             if ((fabs(tgt_altitude_ft - altitude_ft) < 1500.0)
1199                     && (fabs(max_vs) < fabs(tgt_vs)))
1200                 tgt_vs = max_vs;
1201
1202             if (fabs(tgt_vs) < fabs(min_vs))
1203                 tgt_vs = min_vs;*/
1204             //cerr << "target vs : after " << tgt_vs << endl;
1205         }
1206     } //else
1207     //    tgt_vs = 0.0;
1208     checkTcas();
1209 }
1210
1211 void FGAIAircraft::updatePitchAngleTarget() {
1212     // if on ground and above vRotate -> initial rotation
1213     if (onGround() && (speed > _performance->vRotate()))
1214         tgt_pitch = 8.0; // some rough B737 value
1215
1216     //TODO pitch angle on approach and landing
1217
1218     // match pitch angle to vertical speed
1219     else if (tgt_vs > 0) {
1220         tgt_pitch = tgt_vs * 0.005;
1221     } else {
1222         tgt_pitch = tgt_vs * 0.002;
1223     }
1224 }
1225
1226 string FGAIAircraft::atGate() {
1227      string tmp("");
1228      if (fp->getLeg() < 3) {
1229          if (trafficRef) {
1230              if (fp->getGate() > 0) {
1231                  FGParking *park =
1232                      trafficRef->getDepartureAirport()->getDynamics()->getParking(fp->getGate());
1233                  tmp = park->getName();
1234              }
1235          }
1236      }
1237      return tmp;
1238 }
1239
1240 void FGAIAircraft::handleATCRequests() {
1241     //TODO implement NullController for having no ATC to save the conditionals
1242     if (controller) {
1243         controller->updateAircraftInformation(getID(),
1244                                               pos.getLatitudeDeg(),
1245                                               pos.getLongitudeDeg(),
1246                                               hdg,
1247                                               speed,
1248                                               altitude_ft, dt);
1249         processATC(controller->getInstruction(getID()));
1250     }
1251     if (towerController) {
1252         towerController->updateAircraftInformation(getID(),
1253                                               pos.getLatitudeDeg(),
1254                                               pos.getLongitudeDeg(),
1255                                               hdg,
1256                                               speed,
1257                                               altitude_ft, dt);
1258     }
1259 }
1260
1261 void FGAIAircraft::updateActualState() {
1262     //update current state
1263     //TODO have a single tgt_speed and check speed limit on ground on setting tgt_speed
1264     updatePosition();
1265
1266     if (onGround())
1267         speed = _performance->actualSpeed(this, groundTargetSpeed, dt);
1268     else
1269         speed = _performance->actualSpeed(this, (tgt_speed *speedFraction), dt);
1270     assertSpeed(speed);
1271     updateHeading();
1272     roll = _performance->actualBankAngle(this, tgt_roll, dt);
1273
1274     // adjust altitude (meters) based on current vertical speed (fpm)
1275     altitude_ft += vs / 60.0 * dt;
1276     pos.setElevationFt(altitude_ft);
1277
1278     vs = _performance->actualVerticalSpeed(this, tgt_vs, dt);
1279     pitch = _performance->actualPitch(this, tgt_pitch, dt);
1280 }
1281
1282 void FGAIAircraft::updateSecondaryTargetValues() {
1283     // derived target state values
1284     updateBankAngleTarget();
1285     updateVerticalSpeedTarget();
1286     updatePitchAngleTarget();
1287
1288     //TODO calculate wind correction angle (tgt_yaw)
1289 }
1290
1291
1292 bool FGAIAircraft::reachedEndOfCruise(double &distance) {
1293     FGAIWaypoint* curr = fp->getCurrentWaypoint();
1294     if (curr->getName() == string("BOD")) {
1295         double dist = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
1296         double descentSpeed = (getPerformance()->vDescent() * SG_NM_TO_METER) / 3600.0;     // convert from kts to meter/s
1297         double descentRate  = (getPerformance()->descentRate() * SG_FEET_TO_METER) / 60.0;  // convert from feet/min to meter/s
1298
1299         double verticalDistance  = ((altitude_ft - 2000.0) - trafficRef->getArrivalAirport()->getElevation()) *SG_FEET_TO_METER;
1300         double descentTimeNeeded = verticalDistance / descentRate;
1301         double distanceCovered   = descentSpeed * descentTimeNeeded;
1302
1303         //cerr << "Tracking  : " << fgGetString("/ai/track-callsign");
1304         if (trafficRef->getCallSign() == fgGetString("/ai/track-callsign")) {
1305             cerr << "Checking for end of cruise stage for :" << trafficRef->getCallSign() << endl;
1306             cerr << "Descent rate      : " << descentRate << endl;
1307             cerr << "Descent speed     : " << descentSpeed << endl;
1308             cerr << "VerticalDistance  : " << verticalDistance << ". Altitude : " << altitude_ft << ". Elevation " << trafficRef->getArrivalAirport()->getElevation() << endl;
1309             cerr << "DecentTimeNeeded  : " << descentTimeNeeded << endl;
1310             cerr << "DistanceCovered   : " << distanceCovered   << endl;
1311         }
1312         //cerr << "Distance = " << distance << endl;
1313         distance = distanceCovered;
1314         if (dist < distanceCovered) {
1315               if (trafficRef->getCallSign() == fgGetString("/ai/track-callsign")) {
1316                    //exit(1);
1317               }
1318               return true;
1319         } else {
1320               return false;
1321         }
1322     } else {
1323          return false;
1324     }
1325 }
1326
1327 void FGAIAircraft::resetPositionFromFlightPlan()
1328 {
1329     // the one behind you
1330     FGAIWaypoint* prev = 0;
1331     // the one ahead
1332     FGAIWaypoint* curr = 0;
1333     // the next plus 1
1334     FGAIWaypoint* next = 0;
1335
1336     prev = fp->getPreviousWaypoint();
1337     curr = fp->getCurrentWaypoint();
1338     next = fp->getNextWaypoint();
1339
1340     setLatitude(prev->getLatitude());
1341     setLongitude(prev->getLongitude());
1342     double tgt_heading = fp->getBearing(curr, next);
1343     setHeading(tgt_heading);
1344     setAltitude(prev->getAltitude());
1345     setSpeed(prev->getSpeed());
1346 }
1347
1348 double FGAIAircraft::getBearing(double crse)
1349 {
1350   double hdgDiff = fabs(hdg-crse);
1351   if (hdgDiff > 180)
1352       hdgDiff = fabs(hdgDiff - 360);
1353   return hdgDiff;
1354 }
1355
1356 time_t FGAIAircraft::checkForArrivalTime(string wptName) {
1357      FGAIWaypoint* curr = 0;
1358      curr = fp->getCurrentWaypoint();
1359
1360      double tracklength = fp->checkTrackLength(wptName);
1361      if (tracklength > 0.1) {
1362           tracklength += fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
1363      } else {
1364          return 0;
1365      }
1366      time_t now = time(NULL) + fgGetLong("/sim/time/warp");
1367      time_t arrivalTime = fp->getArrivalTime();
1368
1369      time_t ete = tracklength / ((speed * SG_NM_TO_METER) / 3600.0);
1370      time_t secondsToGo = arrivalTime - now;
1371      if (trafficRef->getCallSign() == fgGetString("/ai/track-callsign")) {
1372           cerr << "Checking arrival time: ete " << ete << ". Time to go : " << secondsToGo << ". Track length = " << tracklength << endl;
1373      }
1374      return (ete - secondsToGo); // Positive when we're too slow...
1375 }