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/math/point3d.hxx>
  26 #include <simgear/route/waypoint.hxx>
  27 #include <Main/fg_props.hxx>
  28 #include <Main/globals.hxx>
  29 #include <Main/viewer.hxx>
  30 #include <Scenery/scenery.hxx>
  31 #include <Scenery/tilemgr.hxx>
  32
  33 #include <string>
  34 #include <math.h>
  35 #include <time.h>
  36 #ifdef _MSC_VER
  37 #  include <float.h>
  38 #  define finite _finite
  39 #elif defined(__sun) || defined(sgi)
  40 #  include <ieeefp.h>
  41 #endif
  42
  43 SG_USING_STD(string);
  44
  45 #include "AIAircraft.hxx"
  46 //#include <Airports/trafficcontroller.hxx>
  47
  48 static string tempReg;
  49 //
  50 // accel, decel, climb_rate, descent_rate, takeoff_speed, climb_speed,
  51 // cruise_speed, descent_speed, land_speed
  52 //
  53
  54 const FGAIAircraft::PERF_STRUCT FGAIAircraft::settings[] =
  55 {
  56     // light aircraft
  57     {2.0, 2.0,  450.0, 1000.0,  70.0,  80.0, 100.0,  80.0,  60.0},
  58     // ww2_fighter
  59     {4.0, 2.0, 3000.0, 1500.0, 110.0, 180.0, 250.0, 200.0, 100.0},
  60     // jet_transport
  61     {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0},
  62     // jet_fighter
  63     {7.0, 3.0, 4000.0, 2000.0, 150.0, 350.0, 500.0, 350.0, 150.0},
  64     // tanker
  65     {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0},
  66     // ufo (extreme accel/decel)
  67     {30.0, 30.0, 6000.0, 6000.0, 150.0, 300.0, 430.0, 300.0, 130.0}
  68 };
  69
  70 FGAIAircraft::FGAIAircraft(FGAISchedule *ref) : FGAIBase(otAircraft)
  71 {
  72     trafficRef = ref;
  73     if (trafficRef)
  74         groundOffset = trafficRef->getGroundOffset();
  75     else
  76         groundOffset = 0;
  77
  78     fp = 0;
  79     controller = 0;
  80     prevController = 0;
  81     dt_count = 0;
  82     dt_elev_count = 0;
  83     use_perf_vs = true;
  84
  85     no_roll = false;
  86     tgt_speed = 0;
  87     speed = 0;
  88     groundTargetSpeed = 0;
  89
  90     // set heading and altitude locks
  91     hdg_lock = false;
  92     alt_lock = false;
  93     roll = 0;
  94     headingChangeRate = 0.0;
  95
  96     holdPos = false;
  97 }
  98
  99
 100 FGAIAircraft::~FGAIAircraft()
 101 {
 102     //delete fp;
 103     if (controller)
 104         controller->signOff(getID());
 105 }
 106
 107
 108 void FGAIAircraft::readFromScenario(SGPropertyNode* scFileNode)
 109 {
 110     if (!scFileNode)
 111         return;
 112
 113     FGAIBase::readFromScenario(scFileNode);
 114
 115     setPerformance(scFileNode->getStringValue("class", "jet_transport"));
 116     setFlightPlan(scFileNode->getStringValue("flightplan"),
 117         scFileNode->getBoolValue("repeat", false));
 118     setCallSign(scFileNode->getStringValue("callsign"));
 119 }
 120
 121
 122 void FGAIAircraft::bind()
 123 {
 124     FGAIBase::bind();
 125
 126     props->tie("controls/gear/gear-down",
 127         SGRawValueMethods<FGAIAircraft,bool>(*this,
 128         &FGAIAircraft::_getGearDown));
 129     props->setStringValue("callsign", callsign.c_str());
 130 }
 131
 132
 133 void FGAIAircraft::unbind()
 134 {
 135     FGAIBase::unbind();
 136
 137     props->untie("controls/gear/gear-down");
 138 }
 139
 140
 141 void FGAIAircraft::update(double dt)
 142 {
 143     FGAIBase::update(dt);
 144     Run(dt);
 145     Transform();
 146 }
 147
 148
 149 void FGAIAircraft::setPerformance(const std::string& acclass)
 150 {
 151     if (acclass == "light")
 152     {
 153         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::LIGHT]);
 154     }
 155     else if (acclass == "ww2_fighter")
 156     {
 157         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::WW2_FIGHTER]);
 158     }
 159     else if (acclass == "jet_transport")
 160     {
 161         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 162     }
 163     else if (acclass == "jet_fighter")
 164     {
 165         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_FIGHTER]);
 166     }
 167     else if (acclass == "tanker")
 168     {
 169         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 170     }
 171     else if (acclass == "ufo")
 172     {
 173         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::UFO]);
 174     }
 175     else
 176     {
 177         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 178     }
 179 }
 180
 181
 182 void FGAIAircraft::SetPerformance(const PERF_STRUCT *ps)
 183 {
 184
 185     performance = ps;
 186 }
 187
 188
 189 void FGAIAircraft::Run(double dt)
 190 {
 191
 192     FGAIAircraft::dt = dt;
 193     if(!updateTargetValues())
 194         return;
 195
 196     if (controller)
 197     {
 198         controller->update(getID(),
 199             pos.getLatitudeDeg(),
 200             pos.getLongitudeDeg(),
 201             hdg,
 202             speed,
 203             altitude_ft, dt);
 204         processATC(controller->getInstruction(getID()));
 205     }
 206
 207     if (no_roll)
 208     {
 209         adjustSpeed(groundTargetSpeed);
 210     }
 211     else
 212     {
 213         adjustSpeed(tgt_speed);
 214     }
 215
 216     updatePosition();
 217     updateHeading();
 218     updateBankAngles();
 219     updateAltitudes();
 220     updateVerticalSpeed();
 221     matchPitchAngle();
 222 }
 223
 224
 225 void FGAIAircraft::AccelTo(double speed)
 226 {
 227     tgt_speed = speed;
 228 }
 229
 230
 231 void FGAIAircraft::PitchTo(double angle)
 232 {
 233     tgt_pitch = angle;
 234     alt_lock = false;
 235 }
 236
 237
 238 void FGAIAircraft::RollTo(double angle)
 239 {
 240     tgt_roll = angle;
 241     hdg_lock = false;
 242 }
 243
 244
 245 void FGAIAircraft::YawTo(double angle)
 246 {
 247     tgt_yaw = angle;
 248 }
 249
 250
 251 void FGAIAircraft::ClimbTo(double alt_ft )
 252 {
 253     tgt_altitude_ft = alt_ft;
 254     alt_lock = true;
 255 }
 256
 257
 258 void FGAIAircraft::TurnTo(double heading)
 259 {
 260     tgt_heading = heading;
 261     hdg_lock = true;
 262 }
 263
 264
 265 double FGAIAircraft::sign(double x)
 266 {
 267     if (x == 0.0)
 268         return x;
 269     else
 270         return x/fabs(x);
 271 }
 272
 273
 274 void FGAIAircraft::setFlightPlan(const std::string& flightplan, bool repeat)
 275 {
 276     if (!flightplan.empty())
 277     {
 278         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
 279         fp->setRepeat(repeat);
 280         SetFlightPlan(fp);
 281     }
 282 }
 283
 284
 285 void FGAIAircraft::SetFlightPlan(FGAIFlightPlan *f)
 286 {
 287     delete fp;
 288     fp = f;
 289 }
 290
 291
 292 void FGAIAircraft::ProcessFlightPlan( double dt, time_t now )
 293 {
 294
 295     //if (! fpExecutable(now))
 296     //      return;
 297
 298     // the one behind you
 299     FGAIFlightPlan::waypoint* prev = 0;
 300     // the one ahead
 301     FGAIFlightPlan::waypoint* curr = 0;
 302     // the next plus 1
 303     FGAIFlightPlan::waypoint* next = 0;
 304
 305     prev = fp->getPreviousWaypoint();
 306     curr = fp->getCurrentWaypoint();
 307     next = fp->getNextWaypoint();
 308
 309     dt_count += dt;
 310
 311     ///////////////////////////////////////////////////////////////////////////
 312     // Initialize the flightplan
 313     //////////////////////////////////////////////////////////////////////////
 314     if (!prev)
 315     {
 316         handleFirstWaypoint();
 317         return;
 318     }                            // end of initialization
 319
 320     dt_count = 0;
 321
 322     if (! leadPointReached(curr))
 323     {
 324         controlHeading(curr);
 325         controlSpeed(curr, next);
 326     }
 327     else
 328     {
 329         if (curr->finished)      //end of the flight plan
 330         {
 331             if (fp->getRepeat())
 332                 fp->restart();
 333             else
 334                 setDie(true);
 335             return;
 336         }
 337
 338         if (next)
 339         {
 340             //TODO more intelligent method in AIFlightPlan, no need to send data it already has :-)
 341             tgt_heading = fp->getBearing(curr, next);
 342             spinCounter = 0;
 343         }
 344
 345         //TODO let the fp handle this (loading of next leg)
 346         fp->IncrementWaypoint((bool) trafficRef);
 347         if (!(fp->getNextWaypoint()) && trafficRef)
 348             loadNextLeg();
 349
 350         prev = fp->getPreviousWaypoint();
 351         curr = fp->getCurrentWaypoint();
 352         next = fp->getNextWaypoint();
 353
 354         // Now that we have incremented the waypoints, excute some traffic manager specific code
 355         if (trafficRef)
 356         {
 357             //TODO isn't this best executed right at the beginning?
 358             if (! aiTrafficVisible())
 359             {
 360                 setDie(true);
 361                 return;
 362             }
 363
 364             if (! handleAirportEndPoints(prev, now))
 365             {
 366                 setDie(true);
 367                 return;
 368             }
 369
 370             announcePositionToController();
 371
 372         }
 373
 374         if (next)
 375         {
 376             fp->setLeadDistance(speed, tgt_heading, curr, next);
 377         }
 378
 379         if (!(prev->on_ground))  // only update the tgt altitude from flightplan if not on the ground
 380         {
 381             tgt_altitude_ft = prev->altitude;
 382             if (curr->crossat > -1000.0)
 383             {
 384                 use_perf_vs = false;
 385                 tgt_vs = (curr->crossat - altitude_ft) / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 386                     / 6076.0 / speed*60.0);
 387                 tgt_altitude_ft = curr->crossat;
 388             }
 389             else
 390             {
 391                 use_perf_vs = true;
 392             }
 393         }
 394         tgt_speed = prev->speed;
 395         hdg_lock = alt_lock = true;
 396         no_roll = prev->on_ground;
 397     }
 398 }
 399
 400
 401 void FGAIAircraft::initializeFlightPlan()
 402 {
 403
 404 }
 405
 406
 407 bool FGAIAircraft::_getGearDown() const
 408 {
 409     return ((props->getFloatValue("position/altitude-agl-ft") < 900.0)
 410         && (props->getFloatValue("velocities/airspeed-kt")
 411         < performance->land_speed*1.25));
 412 }
 413
 414
 415 void FGAIAircraft::loadNextLeg()
 416 {
 417
 418     int leg;
 419     if ((leg = fp->getLeg())  == 10)
 420     {
 421         trafficRef->next();
 422         leg = 1;
 423         fp->setLeg(leg);
 424     }
 425
 426     FGAirport *dep = trafficRef->getDepartureAirport();
 427     FGAirport *arr = trafficRef->getArrivalAirport();
 428     if (!(dep && arr))
 429     {
 430         setDie(true);
 431
 432     }
 433     else
 434     {
 435         double cruiseAlt = trafficRef->getCruiseAlt() * 100;
 436
 437         fp->create (dep,
 438             arr,
 439             leg,
 440             cruiseAlt,           //(trafficRef->getCruiseAlt() * 100), // convert from FL to feet
 441             trafficRef->getSpeed(),
 442             _getLatitude(),
 443             _getLongitude(),
 444             false,
 445             trafficRef->getRadius(),
 446             trafficRef->getFlightType(),
 447             acType,
 448             company);
 449     }
 450 }
 451
 452
 453 // Note: This code is copied from David Luff's AILocalTraffic
 454 // Warning - ground elev determination is CPU intensive
 455 // Either this function or the logic of how often it is called
 456 // will almost certainly change.
 457
 458 void FGAIAircraft::getGroundElev(double dt)
 459 {
 460     dt_elev_count += dt;
 461
 462     // Update minimally every three secs, but add some randomness
 463     // to prevent all IA objects doing this in synchrony
 464     if (dt_elev_count < (3.0) + (rand() % 10))
 465         return;
 466     else
 467         dt_elev_count = 0;
 468
 469     // Only do the proper hitlist stuff if we are within visible range of the viewer.
 470     if (!invisible)
 471     {
 472         double visibility_meters = fgGetDouble("/environment/visibility-m");
 473
 474         FGViewer* vw = globals->get_current_view();
 475         double course, distance;
 476
 477         SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
 478         SGWayPoint view (vw->getLongitude_deg(), vw->getLatitude_deg(), 0);
 479         view.CourseAndDistance(current, &course, &distance);
 480         if(distance > visibility_meters)
 481         {
 482             //aip.getSGLocation()->set_cur_elev_m(aptElev);
 483             return;
 484         }
 485
 486         // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
 487         double range = 500.0;
 488         if (!globals->get_tile_mgr()->scenery_available(pos.getLatitudeDeg(), pos.getLongitudeDeg(), range))
 489         {
 490             // Try to shedule tiles for that position.
 491             globals->get_tile_mgr()->update( aip.getSGLocation(), range );
 492         }
 493
 494         // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
 495         double alt;
 496         if (globals->get_scenery()->get_elevation_m(pos.getLatitudeDeg(), pos.getLongitudeDeg(), 20000.0, alt, 0))
 497             tgt_altitude_ft = alt * SG_METER_TO_FEET;
 498     }
 499 }
 500
 501
 502 void FGAIAircraft::setCallSign(const string& s)
 503 {
 504     callsign = s;
 505 }
 506
 507
 508 void FGAIAircraft::doGroundAltitude()
 509 {
 510     if (fabs(altitude_ft - (tgt_altitude_ft+groundOffset)) > 1000.0)
 511         altitude_ft = (tgt_altitude_ft + groundOffset);
 512     else
 513         altitude_ft += 0.1 * ((tgt_altitude_ft+groundOffset) - altitude_ft);
 514 }
 515
 516
 517 void FGAIAircraft::announcePositionToController()
 518 {
 519     if (trafficRef)
 520     {
 521         int leg = fp->getLeg();
 522
 523         // Note that leg was been incremented after creating the current leg, so we should use
 524         // leg numbers here that are one higher than the number that is used to create the leg
 525         //
 526         switch (leg)
 527         {
 528             case 3:              // Taxiing to runway
 529                 if (trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork()->exists())
 530                     controller = trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork();
 531                 break;
 532             case 4:              //Take off tower controller
 533                 if (trafficRef->getDepartureAirport()->getDynamics())
 534                 {
 535                     controller = trafficRef->getDepartureAirport()->getDynamics()->getTowerController();
 536                     //if (trafficRef->getDepartureAirport()->getId() == "EHAM") {
 537                     //cerr << trafficRef->getCallSign() << " at runway " << fp->getRunway() << "Ready for departure "
 538                     //   << trafficRef->getFlightType() << " to " << trafficRef->getArrivalAirport()->getId() << endl;
 539                     //  if (controller == 0) {
 540                     //cerr << "Error in assigning controller at " << trafficRef->getDepartureAirport()->getId() << endl;
 541                     //}
 542
 543                 }
 544                 else
 545                 {
 546                     cerr << "Error: Could not find Dynamics at airport : " << trafficRef->getDepartureAirport()->getId() << endl;
 547                 }
 548                 break;
 549             case 9:              // Taxiing for parking
 550                 if (trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork()->exists())
 551                     controller = trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork();
 552                 break;
 553             default:
 554                 controller = 0;
 555                 break;
 556         }
 557
 558         if ((controller != prevController) && (prevController != 0))
 559         {
 560             prevController->signOff(getID());
 561             string callsign =  trafficRef->getCallSign();
 562             if ( trafficRef->getHeavy())
 563                 callsign += "Heavy";
 564             switch (leg)
 565             {
 566                 case 3:
 567                     //cerr << callsign << " ready to taxi to runway " << fp->getRunway() << endl;
 568                     break;
 569                 case 4:
 570                     //cerr << callsign << " at runway " << fp->getRunway() << "Ready for take-off. "
 571                     //     << trafficRef->getFlightRules() << " to " << trafficRef->getArrivalAirport()->getId()
 572                     //     << "(" << trafficRef->getArrivalAirport()->getName() << ")."<< endl;
 573                     break;
 574             }
 575         }
 576         prevController = controller;
 577         if (controller)
 578         {
 579             controller->announcePosition(getID(), fp, fp->getCurrentWaypoint()->routeIndex,
 580                 _getLatitude(), _getLongitude(), hdg, speed, altitude_ft,
 581                 trafficRef->getRadius(), leg, trafficRef->getCallSign());
 582         }
 583     }
 584 }
 585
 586
 587 void FGAIAircraft::processATC(FGATCInstruction instruction)
 588 {
 589     //cerr << "Processing ATC instruction (not Implimented yet)" << endl;
 590     if (instruction.getHoldPattern   ())
 591     {
 592     }
 593
 594     // Hold Position
 595     if (instruction.getHoldPosition  ())
 596     {
 597         if (!holdPos)
 598         {
 599             holdPos = true;
 600         }
 601         AccelTo(0.0);
 602     }
 603     else
 604     {
 605         if (holdPos)
 606         {
 607             //if (trafficRef)
 608             //  cerr << trafficRef->getCallSign() << " Resuming Taxi " << endl;
 609             holdPos = false;
 610         }
 611         // Change speed Instruction. This can only be excecuted when there is no
 612         // Hold position instruction.
 613         if (instruction.getChangeSpeed   ())
 614         {
 615             //  if (trafficRef)
 616             //cerr << trafficRef->getCallSign() << " Changing Speed " << endl;
 617             AccelTo(instruction.getSpeed());
 618         }
 619         else
 620         {
 621             if (fp) AccelTo(fp->getPreviousWaypoint()->speed);
 622         }
 623     }
 624     if (instruction.getChangeHeading ())
 625     {
 626         hdg_lock = false;
 627         TurnTo(instruction.getHeading());
 628     }
 629     else
 630     {
 631         if (fp) {hdg_lock = true;}
 632     }
 633     if (instruction.getChangeAltitude())
 634     {
 635     }
 636
 637 }
 638
 639
 640 void FGAIAircraft::handleFirstWaypoint()
 641 {
 642     bool eraseWaypoints;         //TODO YAGNI
 643     if (trafficRef)
 644     {
 645         eraseWaypoints = true;
 646     }
 647     else
 648     {
 649         eraseWaypoints = false;
 650     }
 651
 652     FGAIFlightPlan::waypoint* prev = 0; // the one behind you
 653     FGAIFlightPlan::waypoint* curr = 0; // the one ahead
 654     FGAIFlightPlan::waypoint* next = 0;// the next plus 1
 655
 656     spinCounter = 0;
 657     tempReg = "";
 658
 659     //TODO fp should handle this
 660     fp->IncrementWaypoint(eraseWaypoints);
 661     if (!(fp->getNextWaypoint()) && trafficRef)
 662         loadNextLeg();
 663
 664     prev = fp->getPreviousWaypoint();   //first waypoint
 665     curr = fp->getCurrentWaypoint();    //second waypoint
 666     next = fp->getNextWaypoint();       //third waypoint (might not exist!)
 667
 668     setLatitude(prev->latitude);
 669     setLongitude(prev->longitude);
 670     setSpeed(prev->speed);
 671     setAltitude(prev->altitude);
 672
 673     if (prev->speed > 0.0)
 674         setHeading(fp->getBearing(prev->latitude, prev->longitude, curr));
 675     else
 676         setHeading(fp->getBearing(curr->latitude, curr->longitude, prev));
 677
 678     // If next doesn't exist, as in incrementally created flightplans for
 679     // AI/Trafficmanager created plans,
 680     // Make sure lead distance is initialized otherwise
 681     if (next)
 682         fp->setLeadDistance(speed, hdg, curr, next);
 683
 684     if (curr->crossat > -1000.0) //use a calculated descent/climb rate
 685     {
 686         use_perf_vs = false;
 687         tgt_vs = (curr->crossat - prev->altitude)
 688             / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 689             / 6076.0 / prev->speed*60.0);
 690         tgt_altitude_ft = curr->crossat;
 691     }
 692     else
 693     {
 694         use_perf_vs = true;
 695         tgt_altitude_ft = prev->altitude;
 696     }
 697     alt_lock = hdg_lock = true;
 698     no_roll = prev->on_ground;
 699     if (no_roll)
 700     {
 701         Transform();             // make sure aip is initialized.
 702         getGroundElev(60.1);     // make sure it's executed first time around, so force a large dt value
 703         doGroundAltitude();
 704     }
 705     // Make sure to announce the aircraft's position
 706     announcePositionToController();
 707     prevSpeed = 0;
 708 }
 709
 710
 711 /**
 712  * Check Execution time (currently once every 100 ms)
 713  * Add a bit of randomization to prevent the execution of all flight plans
 714  * in synchrony, which can add significant periodic framerate flutter.
 715  *
 716  * @param now
 717  * @return
 718  */
 719 bool FGAIAircraft::fpExecutable(time_t now)
 720 {
 721     double rand_exec_time = (rand() % 100) / 100;
 722     return (dt_count > (0.1+rand_exec_time)) && (fp->isActive(now));
 723 }
 724
 725
 726 /**
 727  * Check to see if we've reached the lead point for our next turn
 728  *
 729  * @param curr
 730  * @return
 731  */
 732 bool FGAIAircraft::leadPointReached(FGAIFlightPlan::waypoint* curr)
 733 {
 734     double dist_to_go = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 735
 736     //cerr << "2" << endl;
 737     double lead_dist = fp->getLeadDistance();
 738     //cerr << " Distance : " << dist_to_go << ": Lead distance " << lead_dist << endl;
 739     // experimental: Use fabs, because speed can be negative (I hope) during push_back.
 740
 741     if (lead_dist < fabs(2*speed))
 742     {
 743         //don't skip over the waypoint
 744         lead_dist = fabs(2*speed);
 745         //cerr << "Extending lead distance to " << lead_dist << endl;
 746     }
 747
 748     //prev_dist_to_go = dist_to_go;
 749     return dist_to_go < lead_dist;
 750 }
 751
 752
 753 bool FGAIAircraft::aiTrafficVisible()
 754 {
 755     double userLatitude  = fgGetDouble("/position/latitude-deg");
 756     double userLongitude = fgGetDouble("/position/longitude-deg");
 757     double course, distance;
 758
 759     SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
 760     SGWayPoint user (userLongitude, userLatitude, 0);
 761
 762     user.CourseAndDistance(current, &course, &distance);
 763
 764     return ((distance * SG_METER_TO_NM) <= TRAFFICTOAIDIST);
 765 }
 766
 767
 768 /**
 769  * Handle release of parking gate, once were taxiing. Also ensure service time at the gate
 770  * in the case of an arrival.
 771  *
 772  * @param prev
 773  * @return
 774  */
 775
 776 //TODO the trafficRef is the right place for the method
 777 bool FGAIAircraft::handleAirportEndPoints(FGAIFlightPlan::waypoint* prev, time_t now)
 778 {
 779     // prepare routing from one airport to another
 780     FGAirport * dep = trafficRef->getDepartureAirport();
 781     FGAirport * arr = trafficRef->getArrivalAirport();
 782
 783     if (!( dep && arr))
 784         return false;
 785
 786     // This waypoint marks the fact that the aircraft has passed the initial taxi
 787     // departure waypoint, so it can release the parking.
 788     if (prev->name == "park2")
 789         dep->getDynamics()->releaseParking(fp->getGate());
 790
 791     // This is the last taxi waypoint, and marks the the end of the flight plan
 792     // so, the schedule should update and wait for the next departure time.
 793     if (prev->name == "END")
 794     {
 795         time_t nextDeparture = trafficRef->getDepartureTime();
 796         // make sure to wait at least 20 minutes at parking to prevent "nervous" taxi behavior
 797         if (nextDeparture < (now+1200))
 798         {
 799             nextDeparture = now + 1200;
 800         }
 801         fp->setTime(nextDeparture);
 802     }
 803
 804     return true;
 805 }
 806
 807
 808 /**
 809  * Check difference between target bearing and current heading and correct if necessary.
 810  *
 811  * @param curr
 812  */
 813 void FGAIAircraft::controlHeading(FGAIFlightPlan::waypoint* curr)
 814 {
 815     double calc_bearing = fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 816     //cerr << "Bearing = " << calc_bearing << endl;
 817     if (speed < 0)
 818     {
 819         calc_bearing +=180;
 820         if (calc_bearing > 360)
 821             calc_bearing -= 360;
 822     }
 823
 824     if (finite(calc_bearing))
 825     {
 826         double hdg_error = calc_bearing - tgt_heading;
 827         if (fabs(hdg_error) > 1.0)
 828         {
 829             TurnTo( calc_bearing );
 830         }
 831
 832     }
 833     else
 834     {
 835         cerr << "calc_bearing is not a finite number : "
 836             << "Speed " << speed
 837             << "pos : " << pos.getLatitudeDeg() << ", " << pos.getLongitudeDeg()
 838             << "waypoint " << curr->latitude << ", " << curr->longitude << endl;
 839         cerr << "waypoint name " << curr->name;
 840         exit(1);                 // FIXME
 841     }
 842 }
 843
 844
 845 /**
 846  * Update the lead distance calculation if speed has changed sufficiently
 847  * to prevent spinning (hopefully);
 848  *
 849  * @param curr
 850  * @param next
 851  */
 852 void FGAIAircraft::controlSpeed(FGAIFlightPlan::waypoint* curr, FGAIFlightPlan::waypoint* next)
 853 {
 854     double speed_diff = speed - prevSpeed;
 855
 856     if (fabs(speed_diff) > 10)
 857     {
 858         prevSpeed = speed;
 859         fp->setLeadDistance(speed, tgt_heading, curr, next);
 860     }
 861 }
 862
 863
 864 /**
 865  * Update target values (heading, alt, speed) depending on flight plan or control properties
 866  */
 867 bool FGAIAircraft::updateTargetValues()
 868 {
 869     if (fp)                      // AI object has a flightplan
 870     {
 871         //TODO make this a function of AIBase
 872         time_t now = time(NULL) + fgGetLong("/sim/time/warp");
 873         //cerr << "UpateTArgetValues() " << endl;
 874         ProcessFlightPlan(dt, now);
 875         if (! fp->isActive(now))
 876         {
 877             // Do execute Ground elev for inactive aircraft, so they
 878             // Are repositioned to the correct ground altitude when the user flies within visibility range.
 879             // In addition, check whether we are out of user range, so this aircraft
 880             // can be deleted.
 881             if (no_roll)
 882             {
 883                 Transform();     // make sure aip is initialized.
 884                 if (trafficRef)
 885                 {
 886                     //cerr << trafficRef->getRegistration() << " Setting altitude to " << altitude_ft;
 887                     if (! aiTrafficVisible())
 888                     {
 889                         setDie(true);
 890                         return false;
 891                     }
 892                     getGroundElev(dt);
 893                     doGroundAltitude();
 894                     // Transform();
 895                     pos.setElevationFt(altitude_ft);
 896                 }
 897             }
 898             return false;
 899         }
 900     }
 901     else
 902     {
 903         // no flight plan, update target heading, speed, and altitude
 904         // from control properties.  These default to the initial
 905         // settings in the config file, but can be changed "on the
 906         // fly".
 907         string lat_mode = props->getStringValue("controls/flight/lateral-mode");
 908         if ( lat_mode == "roll" )
 909         {
 910             double angle
 911                 = props->getDoubleValue("controls/flight/target-roll" );
 912             RollTo( angle );
 913         }
 914         else
 915         {
 916             double angle
 917                 = props->getDoubleValue("controls/flight/target-hdg" );
 918             TurnTo( angle );
 919         }
 920
 921         string lon_mode
 922             = props->getStringValue("controls/flight/longitude-mode");
 923         if ( lon_mode == "alt" )
 924         {
 925             double alt = props->getDoubleValue("controls/flight/target-alt" );
 926             ClimbTo( alt );
 927         }
 928         else
 929         {
 930             double angle
 931                 = props->getDoubleValue("controls/flight/target-pitch" );
 932             PitchTo( angle );
 933         }
 934
 935         AccelTo( props->getDoubleValue("controls/flight/target-spd" ) );
 936     }
 937     return true;
 938 }
 939
 940
 941 /**
 942  * Adjust the speed (accelerate/decelerate) to tgt_speed.
 943  */
 944 void FGAIAircraft::adjustSpeed(double tgt_speed)
 945 {
 946     double speed_diff = tgt_speed - speed;
 947     speed_diff = groundTargetSpeed - speed;
 948
 949     if (speed_diff > 0.0)        // need to accelerate
 950     {
 951         speed += performance->accel * dt;
 952         if ( speed > tgt_speed )
 953             speed = tgt_speed;
 954
 955     }
 956     else if (speed_diff < 0.0)
 957     {
 958         if (no_roll)
 959         {
 960             // on ground (aircraft can't roll)
 961             // deceleration performance is better due to wheel brakes.
 962             speed -= performance->decel * dt * 3;
 963         }
 964         else
 965         {
 966             speed -= performance->decel * dt;
 967         }
 968
 969         if ( speed < tgt_speed )
 970             speed = tgt_speed;
 971
 972     }
 973 }
 974
 975
 976 void FGAIAircraft::updatePosition()
 977 {
 978     // convert speed to degrees per second
 979     double speed_north_deg_sec = cos( hdg * SGD_DEGREES_TO_RADIANS )
 980         * speed * 1.686 / ft_per_deg_lat;
 981     double speed_east_deg_sec  = sin( hdg * SGD_DEGREES_TO_RADIANS )
 982         * speed * 1.686 / ft_per_deg_lon;
 983
 984     // set new position
 985     pos.setLatitudeDeg( pos.getLatitudeDeg() + speed_north_deg_sec * dt);
 986     pos.setLongitudeDeg( pos.getLongitudeDeg() + speed_east_deg_sec * dt);
 987 }
 988
 989
 990 void FGAIAircraft::updateHeading()
 991 {
 992     // adjust heading based on current bank angle
 993     if (roll == 0.0)
 994         roll = 0.01;
 995
 996     if (roll != 0.0)
 997     {
 998         // double turnConstant;
 999         //if (no_roll)
1000         //  turnConstant = 0.0088362;
1001         //else
1002         //  turnConstant = 0.088362;
1003         // If on ground, calculate heading change directly
1004         if (no_roll)
1005         {
1006             double headingDiff = fabs(hdg-tgt_heading);
1007
1008             if (headingDiff > 180)
1009                 headingDiff = fabs(headingDiff - 360);
1010
1011             groundTargetSpeed = tgt_speed - (tgt_speed * (headingDiff/45));
1012             if (sign(groundTargetSpeed) != sign(tgt_speed))
1013                 groundTargetSpeed = 0.21 * sign(tgt_speed); // to prevent speed getting stuck in 'negative' mode
1014
1015             if (headingDiff > 30.0)
1016             {
1017                 // invert if pushed backward
1018                 headingChangeRate += dt * sign(roll);
1019
1020                 if (headingChangeRate > 30)
1021                     headingChangeRate = 30;
1022                 else if (headingChangeRate < -30)
1023                     headingChangeRate = -30;
1024
1025             }
1026             else
1027             {
1028                 if (fabs(headingChangeRate) > headingDiff)
1029                     headingChangeRate = headingDiff*sign(roll);
1030                 else
1031                     headingChangeRate += dt * sign(roll);
1032             }
1033             hdg += headingChangeRate * dt;
1034         }
1035         else
1036         {
1037             if (fabs(speed) > 1.0)
1038             {
1039                 turn_radius_ft = 0.088362 * speed * speed
1040                     / tan( fabs(roll) / SG_RADIANS_TO_DEGREES );
1041             }
1042             else
1043             {
1044                 // Check if turn_radius_ft == 0; this might lead to a division by 0.
1045                 turn_radius_ft = 1.0;
1046             }
1047             double turn_circum_ft = SGD_2PI * turn_radius_ft;
1048             double dist_covered_ft = speed * 1.686 * dt;
1049             double alpha = dist_covered_ft / turn_circum_ft * 360.0;
1050             hdg += alpha * sign(roll);
1051         }
1052         while ( hdg > 360.0 )
1053         {
1054             hdg -= 360.0;
1055             spinCounter++;
1056         }
1057         while ( hdg < 0.0)
1058         {
1059             hdg += 360.0;
1060             spinCounter--;
1061         }
1062     }
1063 }
1064
1065
1066 void FGAIAircraft::updateBankAngles()
1067 {
1068     // adjust target bank angle if heading lock engaged
1069     if (hdg_lock)
1070     {
1071         double bank_sense = 0.0;
1072         double diff = fabs(hdg - tgt_heading);
1073         if (diff > 180)
1074             diff = fabs(diff - 360);
1075
1076         double sum = hdg + diff;
1077         if (sum > 360.0)
1078             sum -= 360.0;
1079         if (fabs(sum - tgt_heading) < 1.0)
1080         {
1081             bank_sense = 1.0;    // right turn
1082         }
1083         else
1084         {
1085             bank_sense = -1.0;   // left turn
1086         }
1087         if (diff < 30)
1088         {
1089             tgt_roll = diff * bank_sense;
1090         }
1091         else
1092         {
1093             tgt_roll = 30.0 * bank_sense;
1094         }
1095         if ((fabs((double) spinCounter) > 1) && (diff > 30))
1096         {
1097             tgt_speed *= 0.999;  // Ugly hack: If aircraft get stuck, they will continually spin around.
1098             // The only way to resolve this is to make them slow down.
1099         }
1100     }
1101
1102     // adjust bank angle, use 9 degrees per second
1103     double bank_diff = tgt_roll - roll;
1104     if (fabs(bank_diff) > 0.2)
1105     {
1106         if (bank_diff > 0.0)
1107             roll += 9.0 * dt;
1108
1109         if (bank_diff < 0.0)
1110             roll -= 9.0 * dt;
1111         //while (roll > 180) roll -= 360;
1112         //while (roll < 180) roll += 360;
1113     }
1114 }
1115
1116
1117 void FGAIAircraft::updateAltitudes()
1118 {
1119     // adjust altitude (meters) based on current vertical speed (fpm)
1120     altitude_ft += vs / 60.0 * dt;
1121     pos.setElevationFt(altitude_ft);
1122
1123     // adjust target Altitude, based on ground elevation when on ground
1124     if (no_roll)
1125     {
1126         getGroundElev(dt);
1127         doGroundAltitude();
1128     }
1129     else
1130     {
1131         // find target vertical speed if altitude lock engaged
1132         if (alt_lock && use_perf_vs)
1133         {
1134             if (altitude_ft < tgt_altitude_ft)
1135             {
1136                 tgt_vs = tgt_altitude_ft - altitude_ft;
1137                 if (tgt_vs > performance->climb_rate)
1138                     tgt_vs = performance->climb_rate;
1139             }
1140             else
1141             {
1142                 tgt_vs = tgt_altitude_ft - altitude_ft;
1143                 if (tgt_vs  < (-performance->descent_rate))
1144                     tgt_vs = -performance->descent_rate;
1145             }
1146         }
1147
1148         if (alt_lock && !use_perf_vs)
1149         {
1150             double max_vs = 4*(tgt_altitude_ft - altitude_ft);
1151             double min_vs = 100;
1152             if (tgt_altitude_ft < altitude_ft)
1153                 min_vs = -100.0;
1154             if ((fabs(tgt_altitude_ft - altitude_ft) < 1500.0)
1155                 && (fabs(max_vs) < fabs(tgt_vs)))
1156                 tgt_vs = max_vs;
1157
1158             if (fabs(tgt_vs) < fabs(min_vs))
1159                 tgt_vs = min_vs;
1160         }
1161     }
1162 }
1163
1164
1165 void FGAIAircraft::updateVerticalSpeed()
1166 {
1167     // adjust vertical speed
1168     double vs_diff = tgt_vs - vs;
1169     if (fabs(vs_diff) > 10.0)
1170     {
1171         if (vs_diff > 0.0)
1172         {
1173             vs += (performance->climb_rate / 3.0) * dt;
1174
1175             if (vs > tgt_vs)
1176                 vs = tgt_vs;
1177         }
1178         else
1179         {
1180             vs -= (performance->descent_rate / 3.0) * dt;
1181
1182             if (vs < tgt_vs)
1183                 vs = tgt_vs;
1184         }
1185     }
1186 }
1187
1188
1189 void FGAIAircraft::matchPitchAngle()
1190 {
1191     // match pitch angle to vertical speed
1192     if (vs > 0)
1193     {
1194         pitch = vs * 0.005;
1195     }
1196     else
1197     {
1198         pitch = vs * 0.002;
1199     }
1200 }