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    static string tempReg;
  48 //
  49 // accel, decel, climb_rate, descent_rate, takeoff_speed, climb_speed,
  50 // cruise_speed, descent_speed, land_speed
  51 //
  52 const FGAIAircraft::PERF_STRUCT FGAIAircraft::settings[] = {
  53     // light aircraft
  54     {2.0, 2.0,  450.0, 1000.0,  70.0,  80.0, 100.0,  80.0,  60.0},
  55     // ww2_fighter
  56     {4.0, 2.0, 3000.0, 1500.0, 110.0, 180.0, 250.0, 200.0, 100.0},
  57     // jet_transport
  58     {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0},
  59     // jet_fighter
  60     {7.0, 3.0, 4000.0, 2000.0, 150.0, 350.0, 500.0, 350.0, 150.0},
  61     // tanker
  62     {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0},
  63     // ufo (extreme accel/decel)
  64     {30.0, 30.0, 6000.0, 6000.0, 150.0, 300.0, 430.0, 300.0, 130.0}
  65 };
  66
  67
  68 FGAIAircraft::FGAIAircraft(FGAISchedule *ref) :
  69     FGAIBase(otAircraft)
  70 {
  71     trafficRef = ref;
  72     if (trafficRef)
  73         groundOffset = trafficRef->getGroundOffset();
  74     else
  75         groundOffset = 0;
  76
  77     fp = 0;
  78     controller = 0;
  79     prevController = 0;
  80     dt_count = 0;
  81     dt_elev_count = 0;
  82     use_perf_vs = true;
  83     isTanker = false;
  84
  85     // set heading and altitude locks
  86     hdg_lock = false;
  87     alt_lock = false;
  88     roll = 0;
  89     headingChangeRate = 0.0;
  90
  91     holdPos = false;
  92 }
  93
  94
  95 FGAIAircraft::~FGAIAircraft() {
  96     //delete fp;
  97   if (controller)
  98     controller->signOff(getID());
  99 }
 100
 101
 102 void FGAIAircraft::readFromScenario(SGPropertyNode* scFileNode) {
 103     if (!scFileNode)
 104         return;
 105
 106     FGAIBase::readFromScenario(scFileNode);
 107
 108     setPerformance(scFileNode->getStringValue("class", "jet_transport"));
 109     setFlightPlan(scFileNode->getStringValue("flightplan"),
 110                   scFileNode->getBoolValue("repeat", false));
 111     setCallSign(scFileNode->getStringValue("callsign"));
 112     setTACANChannelID(scFileNode->getStringValue("TACAN-channel-ID"));
 113 }
 114
 115
 116 bool FGAIAircraft::init() {
 117     //refuel_node = fgGetNode("systems/refuel/contact", true);
 118     return FGAIBase::init();
 119 }
 120
 121
 122 void FGAIAircraft::bind() {
 123     FGAIBase::bind();
 124
 125     props->tie("controls/gear/gear-down",
 126                SGRawValueMethods<FGAIAircraft,bool>(*this,
 127                                               &FGAIAircraft::_getGearDown));
 128     props->tie("refuel/contact", SGRawValuePointer<bool>(&contact));
 129     props->setStringValue("callsign", callsign.c_str());
 130     props->setStringValue("navaids/tacan/channel-ID", TACAN_channel_id.c_str());
 131     props->setBoolValue("tanker",isTanker);
 132 }
 133
 134
 135 void FGAIAircraft::unbind() {
 136     FGAIBase::unbind();
 137
 138     props->untie("controls/gear/gear-down");
 139     props->untie("refuel/contact");
 140 }
 141
 142
 143 void FGAIAircraft::update(double dt) {
 144     FGAIBase::update(dt);
 145     Run(dt);
 146     Transform();
 147 }
 148
 149
 150 void FGAIAircraft::setPerformance(const std::string& acclass) {
 151     if (acclass == "light") {
 152         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::LIGHT]);
 153     } else if (acclass == "ww2_fighter") {
 154         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::WW2_FIGHTER]);
 155     } else if (acclass == "jet_transport") {
 156         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 157     } else if (acclass == "jet_fighter") {
 158         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_FIGHTER]);
 159     } else if (acclass == "tanker") {
 160         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 161         SetTanker(true);
 162     } else if (acclass == "ufo") {
 163         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::UFO]);
 164     } else {
 165         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 166     }
 167 }
 168
 169
 170 void FGAIAircraft::SetPerformance(const PERF_STRUCT *ps) {
 171
 172    performance = ps;
 173 }
 174
 175
 176 void FGAIAircraft::Run(double dt) {
 177
 178     FGAIAircraft::dt = dt;
 179
 180     if (fp) {
 181         time_t now = time(NULL) + fgGetLong("/sim/time/warp");
 182         ProcessFlightPlan(dt, now);
 183         if (now < fp->getStartTime()) {
 184             // Do execute Ground elev for inactive aircraft, so they
 185             // Are repositioned to the correct ground altitude when the user flies within visibility range.
 186             // In addition, check whether we are out of user range, so this aircraft
 187             // can be deleted.
 188             if (no_roll) {
 189                 Transform();       // make sure aip is initialized.
 190                 if (trafficRef) {
 191                   double userLatitude  = fgGetDouble("/position/latitude-deg");
 192                   double userLongitude = fgGetDouble("/position/longitude-deg");
 193                   double course, distance;
 194                   SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
 195                   SGWayPoint user (userLongitude, userLatitude, 0);
 196                   user.CourseAndDistance(current, &course, &distance);
 197                   if ((distance * SG_METER_TO_NM) > TRAFFICTOAIDIST) {
 198                     setDie(true);
 199                     return;
 200                   }
 201                   getGroundElev(dt); // make sure it's exectuted first time around, so force a large dt value
 202                   //getGroundElev(dt); // Need to do this twice.
 203                   //cerr << trafficRef->getRegistration() << " Setting altitude to " << tgt_altitude;
 204                   doGroundAltitude();
 205                   //cerr << " Actual altitude " << altitude << endl;
 206                   // Transform();
 207                   pos.setElevationFt(altitude_ft);
 208                 }
 209             }
 210             return;
 211         }
 212     } else {
 213         // no flight plan, update target heading, speed, and altitude
 214         // from control properties.  These default to the initial
 215         // settings in the config file, but can be changed "on the
 216         // fly".
 217         string lat_mode = props->getStringValue("controls/flight/lateral-mode");
 218         if ( lat_mode == "roll" ) {
 219             double angle
 220                 = props->getDoubleValue("controls/flight/target-roll" );
 221             RollTo( angle );
 222         } else {
 223              double angle
 224                 = props->getDoubleValue("controls/flight/target-hdg" );
 225             TurnTo( angle );
 226         }
 227
 228         string lon_mode
 229             = props->getStringValue("controls/flight/longitude-mode");
 230         if ( lon_mode == "alt" ) {
 231             double alt = props->getDoubleValue("controls/flight/target-alt" );
 232             ClimbTo( alt );
 233         } else {
 234             double angle
 235                 = props->getDoubleValue("controls/flight/target-pitch" );
 236             PitchTo( angle );
 237         }
 238
 239         AccelTo( props->getDoubleValue("controls/flight/target-spd" ) );
 240     }
 241     if (controller)
 242       {
 243         controller->update(getID(),
 244                            pos.getLatitudeDeg(),
 245                            pos.getLongitudeDeg(),
 246                            hdg,
 247                            speed,
 248                            altitude_ft, dt);
 249         processATC(controller->getInstruction(getID()));
 250       }
 251
 252     double turn_radius_ft;
 253     double turn_circum_ft;
 254     double speed_north_deg_sec;
 255     double speed_east_deg_sec;
 256     double dist_covered_ft;
 257     double alpha;
 258
 259     // adjust speed
 260     double speed_diff; //= tgt_speed - speed;
 261     if (!no_roll) {
 262         speed_diff = tgt_speed - speed;
 263     } else {
 264         speed_diff = groundTargetSpeed - speed;
 265     }
 266
 267     if (speed_diff > 0.0) {
 268         speed += performance->accel * dt;
 269         if (no_roll) { // apply overshoot correction
 270           if ( speed > groundTargetSpeed ) speed = groundTargetSpeed;
 271         }else {
 272           if ( speed > tgt_speed ) speed = tgt_speed;
 273         }
 274     } else if (speed_diff < 0.0) {
 275         if (no_roll) {
 276             // on ground (aircraft can't roll)
 277             // deceleration performance is better due to wheel brakes.
 278             speed -= performance->decel * dt * 3;
 279         } else {
 280             speed -= performance->decel * dt;
 281         }
 282         if (no_roll) { // apply overshoot correction
 283         if (speed < groundTargetSpeed ) speed = groundTargetSpeed;
 284         } else {
 285           if ( speed < tgt_speed ) speed = tgt_speed;
 286         }
 287     }
 288
 289
 290     // convert speed to degrees per second
 291     speed_north_deg_sec = cos( hdg * SGD_DEGREES_TO_RADIANS )
 292                           * speed * 1.686 / ft_per_deg_lat;
 293     speed_east_deg_sec  = sin( hdg * SGD_DEGREES_TO_RADIANS )
 294                           * speed * 1.686 / ft_per_deg_lon;
 295
 296     // set new position
 297     pos.setLatitudeDeg( pos.getLatitudeDeg() + speed_north_deg_sec * dt);
 298     pos.setLongitudeDeg( pos.getLongitudeDeg() + speed_east_deg_sec * dt);
 299
 300     /* printf("%.7f %0.4f %.7f %.5f %.7f %.7f %.8f %.8f %.9f %.9f\n",
 301            dt, hdg, speed, ft_per_deg_lat,
 302            cos( hdg * SGD_DEGREES_TO_RADIANS ),
 303            speed * 1.686 / ft_per_deg_lat,
 304            speed_north_deg_sec, speed_east_deg_sec,
 305            pos.getLatitudeDeg(), pos.getLongitudeDeg()); */
 306
 307     //if (!(finite(pos.lat()) && finite(pos.lon())))
 308     //  {
 309     //    cerr << "Position is not finite" << endl;
 310     //    cerr << "speed = " << speed << endl;
 311     //    cerr << "dt" << dt << endl;
 312     //    cerr << "heading " << hdg << endl;
 313     //    cerr << "speed east " << speed_east_deg_sec << endl;
 314     //    cerr << "speed nrth " << speed_north_deg_sec << endl;
 315     //    cerr << "deg_lat    " << ft_per_deg_lat << endl;
 316     //    cerr << "deg_lon    " << ft_per_deg_lon << endl;
 317     //  }
 318
 319     // adjust heading based on current bank angle
 320     if (roll == 0.0)
 321         roll = 0.01;
 322
 323     if (roll != 0.0) {
 324         // double turnConstant;
 325         //if (no_roll)
 326         //  turnConstant = 0.0088362;
 327         //else
 328         //  turnConstant = 0.088362;
 329         // If on ground, calculate heading change directly
 330         if (no_roll) {
 331             double headingDiff = fabs(hdg-tgt_heading);
 332
 333             if (headingDiff > 180)
 334                 headingDiff = fabs(headingDiff - 360);
 335
 336             groundTargetSpeed = tgt_speed - (tgt_speed * (headingDiff/45));
 337             if (sign(groundTargetSpeed) != sign(tgt_speed))
 338                 groundTargetSpeed = 0.21 * sign(tgt_speed); // to prevent speed getting stuck in 'negative' mode
 339
 340             if (headingDiff > 30.0) {
 341                 headingChangeRate += dt * sign(roll); // invert if pushed backward
 342                 // Print some debug statements to find out why aircraft may get stuck
 343                 // forever turning
 344                 //if (trafficRef->getDepartureAirport()->getId() == string("EHAM")) {
 345                 //    cerr << "Turning : " << trafficRef->getRegistration()
 346                 //    cerr <<  " Speed = " << speed << " Heading " << hdg
 347                 //         << " Target Heading " << tgt_heading
 348                 //         << " Lead Distance " <<  fp->getLeadDistance()
 349                 //         << " Distance to go "
 350                 //         << fp->getDistanceToGo(pos.lat(), pos.lon(), fp->getCurrentWaypoint())
 351                 //         << "waypoint name " << fp->getCurrentWaypoint()->name
 352                 //         << endl;
 353                 //}
 354                 if (headingChangeRate > 30)
 355                     headingChangeRate = 30;
 356                 else if (headingChangeRate < -30)
 357                     headingChangeRate = -30;
 358
 359             } else {
 360                 if (fabs(headingChangeRate) > headingDiff)
 361                     headingChangeRate = headingDiff*sign(roll);
 362                 else
 363                     headingChangeRate += dt * sign(roll);
 364             }
 365             hdg += headingChangeRate * dt;
 366             //cerr << "On ground. Heading: " << hdg << ". Target Heading: " << tgt_heading
 367             //     << ". Target speed: " << groundTargetSpeed << ". heading change rate"
 368             //     << headingChangeRate << endl;
 369
 370         } else {
 371             if (fabs(speed) > 1.0) {
 372                 turn_radius_ft = 0.088362 * speed * speed
 373                         / tan( fabs(roll) / SG_RADIANS_TO_DEGREES );
 374             } else {
 375                 turn_radius_ft = 1.0; // Check if turn_radius_ft == 0; this might lead to a division by 0.
 376             }
 377             turn_circum_ft = SGD_2PI * turn_radius_ft;
 378             dist_covered_ft = speed * 1.686 * dt;
 379             alpha = dist_covered_ft / turn_circum_ft * 360.0;
 380             hdg += alpha * sign(roll);
 381         }
 382         while ( hdg > 360.0 ) {
 383             hdg -= 360.0;
 384             spinCounter++;
 385         }
 386         while ( hdg < 0.0) {
 387             hdg += 360.0;
 388             spinCounter--;
 389         }
 390     }
 391
 392
 393     // adjust target bank angle if heading lock engaged
 394     if (hdg_lock) {
 395         double bank_sense = 0.0;
 396         double diff = fabs(hdg - tgt_heading);
 397         if (diff > 180)
 398             diff = fabs(diff - 360);
 399
 400         double sum = hdg + diff;
 401         if (sum > 360.0)
 402             sum -= 360.0;
 403         if (fabs(sum - tgt_heading) < 1.0) {
 404             bank_sense = 1.0;   // right turn
 405         } else {
 406             bank_sense = -1.0;  // left turn
 407         }
 408         if (diff < 30) {
 409             tgt_roll = diff * bank_sense;
 410         } else {
 411             tgt_roll = 30.0 * bank_sense;
 412         }
 413         if ((fabs((double) spinCounter) > 1) && (diff > 30)) {
 414             tgt_speed *= 0.999; // Ugly hack: If aircraft get stuck, they will continually spin around.
 415             // The only way to resolve this is to make them slow down.
 416             //if (tempReg.empty())
 417             //  tempReg = trafficRef->getRegistration();
 418             //if (trafficRef->getRegistration() == tempReg) {
 419             //    cerr << trafficRef->getRegistration()
 420             //         << " appears to be spinning: " << spinCounter << endl
 421             //         << " speed          " << speed << endl
 422             //         << " heading        " << hdg << endl
 423             //         << " lead distance  " << fp->getLeadDistance() << endl
 424             //         << " waypoint       " << fp->getCurrentWaypoint()->name
 425             //         << " target heading " << tgt_heading << endl
 426             //         << " lead in angle  " << fp->getLeadInAngle()<< endl
 427             //         << " roll           " << roll << endl
 428             //         << " target_roll    " << tgt_roll << endl;
 429             //}
 430         }
 431     }
 432
 433     // adjust bank angle, use 9 degrees per second
 434     double bank_diff = tgt_roll - roll;
 435     if (fabs(bank_diff) > 0.2) {
 436         if (bank_diff > 0.0)
 437             roll += 9.0 * dt;
 438
 439         if (bank_diff < 0.0)
 440             roll -= 9.0 * dt;
 441         //while (roll > 180) roll -= 360;
 442         //while (roll < 180) roll += 360;
 443     }
 444
 445     // adjust altitude (meters) based on current vertical speed (fpm)
 446     altitude_ft += vs / 60.0 * dt;
 447     pos.setElevationFt(altitude_ft);
 448
 449     // adjust target Altitude, based on ground elevation when on ground
 450     if (no_roll) {
 451         getGroundElev(dt);
 452         doGroundAltitude();
 453     } else {
 454         // find target vertical speed if altitude lock engaged
 455         if (alt_lock && use_perf_vs) {
 456             if (altitude_ft < tgt_altitude_ft) {
 457                 tgt_vs = tgt_altitude_ft - altitude_ft;
 458                 if (tgt_vs > performance->climb_rate)
 459                     tgt_vs = performance->climb_rate;
 460             } else {
 461                 tgt_vs = tgt_altitude_ft - altitude_ft;
 462                 if (tgt_vs  < (-performance->descent_rate))
 463                     tgt_vs = -performance->descent_rate;
 464             }
 465         }
 466
 467         if (alt_lock && !use_perf_vs) {
 468             double max_vs = 4*(tgt_altitude_ft - altitude_ft);
 469             double min_vs = 100;
 470             if (tgt_altitude_ft < altitude_ft)
 471                 min_vs = -100.0;
 472             if ((fabs(tgt_altitude_ft - altitude_ft) < 1500.0)
 473                     && (fabs(max_vs) < fabs(tgt_vs)))
 474                 tgt_vs = max_vs;
 475
 476             if (fabs(tgt_vs) < fabs(min_vs))
 477                 tgt_vs = min_vs;
 478         }
 479     }
 480     // adjust vertical speed
 481     double vs_diff = tgt_vs - vs;
 482     if (fabs(vs_diff) > 10.0) {
 483         if (vs_diff > 0.0) {
 484             vs += (performance->climb_rate / 3.0) * dt;
 485
 486             if (vs > tgt_vs)
 487                 vs = tgt_vs;
 488         } else {
 489             vs -= (performance->descent_rate / 3.0) * dt;
 490
 491            if (vs < tgt_vs)
 492                vs = tgt_vs;
 493         }
 494     }
 495
 496     // match pitch angle to vertical speed
 497     if (vs > 0) {
 498         pitch = vs * 0.005;
 499     } else {
 500         pitch = vs * 0.002;
 501     }
 502
 503     //###########################//
 504     // do calculations for radar //
 505     //###########################//
 506     double range_ft2 = UpdateRadar(manager);
 507
 508     //************************************//
 509     // Tanker code                        //
 510     //************************************//
 511
 512     if ( isTanker) {
 513         if ( (range_ft2 < 250.0 * 250.0) && (y_shift > 0.0)
 514                 && (elevation > 0.0) ) {
 515             //refuel_node->setBoolValue(true);
 516             contact = true;
 517         } else {
 518             //refuel_node->setBoolValue(false);
 519             contact = false;
 520         }
 521     } else {
 522         contact = false;
 523     }
 524 }
 525
 526
 527 void FGAIAircraft::AccelTo(double speed) {
 528     tgt_speed = speed;
 529 }
 530
 531
 532 void FGAIAircraft::PitchTo(double angle) {
 533     tgt_pitch = angle;
 534     alt_lock = false;
 535 }
 536
 537
 538 void FGAIAircraft::RollTo(double angle) {
 539     tgt_roll = angle;
 540     hdg_lock = false;
 541 }
 542
 543
 544 void FGAIAircraft::YawTo(double angle) {
 545     tgt_yaw = angle;
 546 }
 547
 548
 549 void FGAIAircraft::ClimbTo(double alt_ft ) {
 550     tgt_altitude_ft = alt_ft;
 551     alt_lock = true;
 552 }
 553
 554
 555 void FGAIAircraft::TurnTo(double heading) {
 556     tgt_heading = heading;
 557     hdg_lock = true;
 558 }
 559
 560
 561 double FGAIAircraft::sign(double x) {
 562     if ( x < 0.0 )
 563         return -1.0;
 564     else
 565         return 1.0;
 566 }
 567
 568
 569 void FGAIAircraft::setFlightPlan(const std::string& flightplan, bool repeat) {
 570     if (!flightplan.empty()) {
 571         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
 572         fp->setRepeat(repeat);
 573         SetFlightPlan(fp);
 574     }
 575 }
 576
 577
 578 void FGAIAircraft::SetFlightPlan(FGAIFlightPlan *f) {
 579     delete fp;
 580     fp = f;
 581 }
 582
 583
 584 void FGAIAircraft::ProcessFlightPlan( double dt, time_t now ) {
 585     bool eraseWaypoints;
 586     if (trafficRef) {
 587         eraseWaypoints = true;
 588     } else
 589         eraseWaypoints = false;
 590
 591
 592     FGAIFlightPlan::waypoint* prev = 0; // the one behind you
 593     FGAIFlightPlan::waypoint* curr = 0; // the one ahead
 594     FGAIFlightPlan::waypoint* next = 0; // the next plus 1
 595     prev = fp->getPreviousWaypoint();
 596     curr = fp->getCurrentWaypoint();
 597     next = fp->getNextWaypoint();
 598     dt_count += dt;
 599
 600     ///////////////////////////////////////////////////////////////////////////
 601     // Initialize the flightplan
 602     //////////////////////////////////////////////////////////////////////////
 603     if (!prev) {
 604
 605       spinCounter = 0;
 606       tempReg = "";
 607       fp->IncrementWaypoint(eraseWaypoints);
 608       if (!(fp->getNextWaypoint()) && trafficRef)
 609         loadNextLeg();
 610
 611       prev = fp->getPreviousWaypoint(); //first waypoint
 612       curr = fp->getCurrentWaypoint();  //second waypoint
 613       next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 614
 615       setLatitude(prev->latitude);
 616       setLongitude(prev->longitude);
 617       setSpeed(prev->speed);
 618       setAltitude(prev->altitude);
 619
 620       if (prev->speed > 0.0)
 621         setHeading(fp->getBearing(prev->latitude, prev->longitude, curr));
 622       else
 623         setHeading(fp->getBearing(curr->latitude, curr->longitude, prev));
 624
 625       // If next doesn't exist, as in incrementally created flightplans for
 626       // AI/Trafficmanager created plans,
 627       // Make sure lead distance is initialized otherwise
 628       if (next)
 629         fp->setLeadDistance(speed, hdg, curr, next);
 630
 631       if (curr->crossat > -1000.0) { //use a calculated descent/climb rate
 632         use_perf_vs = false;
 633         tgt_vs = (curr->crossat - prev->altitude)
 634           / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 635              / 6076.0 / prev->speed*60.0);
 636         tgt_altitude_ft = curr->crossat;
 637       } else {
 638         use_perf_vs = true;
 639         tgt_altitude_ft = prev->altitude;
 640       }
 641       alt_lock = hdg_lock = true;
 642       no_roll = prev->on_ground;
 643       if (no_roll) {
 644         Transform();         // make sure aip is initialized.
 645         getGroundElev(60.1); // make sure it's exectuted first time around, so force a large dt value
 646         doGroundAltitude();
 647       }
 648       // Make sure to announce the aircraft's position
 649       announcePositionToController();
 650       prevSpeed = 0;
 651       return;
 652     } // end of initialization
 653
 654     ///////////////////////////////////////////////////////////////////////////
 655     // Check Execution time (currently once every 100 ms
 656     ///////////////////////////////////////////////////////////////////////////
 657     if ((dt_count < 0.1) || (now < fp->getStartTime())) {
 658       //cerr  << "done fp dt" << endl;
 659       return;
 660     } else {
 661       dt_count = 0;
 662     }
 663     // check to see if we've reached the lead point for our next turn
 664     double dist_to_go = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 665
 666     //cerr << "2" << endl;
 667     double lead_dist = fp->getLeadDistance();
 668     //cerr << " Distance : " << dist_to_go << ": Lead distance " << lead_dist << endl;
 669     // experimental: Use fabs, because speed can be negative (I hope) during push_back.
 670
 671     if (lead_dist < fabs(2*speed)) {
 672         lead_dist = fabs(2*speed);  //don't skip over the waypoint
 673         //cerr << "Extending lead distance to " << lead_dist << endl;
 674     }
 675
 676     //prev_dist_to_go = dist_to_go;
 677
 678     if ( dist_to_go < lead_dist ) {
 679         if (curr->finished) {  //end of the flight plan
 680             if (fp->getRepeat())
 681                 fp->restart();
 682             else
 683                 setDie(true);
 684             return;
 685         }
 686
 687         if (next) {
 688             tgt_heading = fp->getBearing(curr, next);
 689             spinCounter = 0;
 690         }
 691
 692         fp->IncrementWaypoint(eraseWaypoints);
 693         if (!(fp->getNextWaypoint()) && trafficRef)
 694             loadNextLeg();
 695
 696         prev = fp->getPreviousWaypoint();
 697         curr = fp->getCurrentWaypoint();
 698         next = fp->getNextWaypoint();
 699
 700         // Now that we have incremented the waypoints, excute some traffic manager specific code
 701         if (trafficRef) {
 702             double userLatitude  = fgGetDouble("/position/latitude-deg");
 703             double userLongitude = fgGetDouble("/position/longitude-deg");
 704             double course, distance;
 705             SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
 706             SGWayPoint user (userLongitude, userLatitude, 0);
 707             user.CourseAndDistance(current, &course, &distance);
 708             if ((distance * SG_METER_TO_NM) > TRAFFICTOAIDIST) {
 709                 setDie(true);
 710                 return;
 711             }
 712
 713             FGAirport * dep = trafficRef->getDepartureAirport();
 714             FGAirport * arr = trafficRef->getArrivalAirport();
 715             if (!( dep && arr)) {
 716                 setDie(true);
 717                 return;
 718             }
 719             // This waypoint marks the fact that the aircraft has passed the initial taxi
 720             // departure waypoint, so it can release the parking.
 721             if (prev->name == "park2")
 722                 dep->getDynamics()->releaseParking(fp->getGate());
 723             // This is the last taxi waypoint, and marks the the end of the flight plan
 724             // so, the schedule should update and wait for the next departure time.
 725             if (prev->name == "END") {
 726               // make sure to wait at least 20 minutes at parking to prevent "nervous" taxi behavior
 727               // delayed aircraft.
 728               time_t nextDeparture = trafficRef->getDepartureTime();
 729               if (nextDeparture < (now+1200)) {
 730                 nextDeparture = now + 1200;
 731               }
 732               fp->setTime(trafficRef->getDepartureTime());
 733             }
 734             announcePositionToController();
 735
 736         }
 737
 738         if (next) {
 739             //cerr << "Current waypoint" << curr->name << endl;
 740             //cerr << "Next waypoint" << next->name << endl;
 741             fp->setLeadDistance(speed, tgt_heading, curr, next);
 742         }
 743
 744         //cerr << "5.1" << endl;
 745         if (!(prev->on_ground)) { // only update the tgt altitude from flightplan if not on the ground
 746             tgt_altitude_ft = prev->altitude;
 747             if (curr->crossat > -1000.0) {
 748                 //cerr << "5.1a" << endl;
 749                 use_perf_vs = false;
 750                 tgt_vs = (curr->crossat - altitude_ft) / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 751                         / 6076.0 / speed*60.0);
 752                 //cerr << "5.1b" << endl;
 753                 tgt_altitude_ft = curr->crossat;
 754             } else {
 755                 //cerr << "5.1c" << endl;
 756                 use_perf_vs = true;
 757                 //cerr << "5.1d" << endl;
 758                 //cerr << "Setting target altitude : " <<tgt_altitude_ft << endl;
 759             }
 760         }
 761         //cerr << "6" << endl;
 762         tgt_speed = prev->speed;
 763         hdg_lock = alt_lock = true;
 764         no_roll = prev->on_ground;
 765         //cout << "Crossing waypoint: " << prev->name << endl;
 766         //cout << "  Target speed:    " << tgt_speed << endl;
 767         //cout << "  Target altitude: " << tgt_altitude_ft << endl;
 768         //cout << "  Target heading:  " << tgt_heading << endl << endl;
 769
 770     } else {
 771         double calc_bearing = fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 772         //cerr << "Bearing = " << calc_bearing << endl;
 773         if (speed < 0) {
 774             calc_bearing +=180;
 775             if (calc_bearing > 360)
 776                 calc_bearing -= 360;
 777         }
 778
 779         if (finite(calc_bearing)) {
 780             double hdg_error = calc_bearing - tgt_heading;
 781             if (fabs(hdg_error) > 1.0) {
 782                 TurnTo( calc_bearing );
 783             }
 784
 785         } else {
 786             cerr << "calc_bearing is not a finite number : "
 787                  << "Speed " << speed
 788                  << "pos : " << pos.getLatitudeDeg() << ", " << pos.getLongitudeDeg()
 789                  << "waypoint " << curr->latitude << ", " << curr->longitude << endl;
 790             cerr << "waypoint name " << curr->name;
 791             exit(1);  // FIXME
 792         }
 793
 794         double speed_diff = speed - prevSpeed;
 795         // Update the lead distance calculation if speed has changed sufficiently
 796         // to prevent spinning (hopefully);
 797         if (fabs(speed_diff) > 10) {
 798             prevSpeed = speed;
 799             fp->setLeadDistance(speed, tgt_heading, curr, next);
 800         }
 801
 802         //cerr << "Done Processing FlightPlan"<< endl;
 803     }
 804 }
 805
 806 void FGAIAircraft::initializeFlightPlan()
 807 {
 808
 809 }
 810
 811
 812 bool FGAIAircraft::_getGearDown() const {
 813     return ((props->getFloatValue("position/altitude-agl-ft") < 900.0)
 814             && (props->getFloatValue("velocities/airspeed-kt")
 815             < performance->land_speed*1.25));
 816 }
 817
 818
 819 void FGAIAircraft::loadNextLeg() {
 820     //delete fp;
 821     //time_t now = time(NULL) + fgGetLong("/sim/time/warp");
 822
 823     //FGAIModelEntity entity;
 824     //entity.m_class = "jet_transport";
 825     //entity.path = modelPath.c_str();
 826     //entity.flightplan = "none";
 827     //entity.latitude = _getLatitude();
 828     //entity.longitude = _getLongitude();
 829     //entity.altitude = trafficRef->getCruiseAlt() * 100; // convert from FL to feet
 830     //entity.speed = 450; // HACK ALERT
 831     //entity.fp = new FGAIFlightPlan(&entity, courseToDest, i->getDepartureTime(), dep, arr);
 832     int leg;
 833     if ((leg = fp->getLeg())  == 10) {
 834         trafficRef->next();
 835         leg = 1;
 836         fp->setLeg(leg);
 837         //cerr << "Resetting leg : " << leg << endl;
 838     }
 839     //leg++;
 840     //fp->setLeg(leg);
 841     //cerr << "Creating leg number : " << leg << endl;
 842     FGAirport *dep = trafficRef->getDepartureAirport();
 843     FGAirport *arr = trafficRef->getArrivalAirport();
 844     if (!(dep && arr)) {
 845         setDie(true);
 846         //cerr << "Failed to get airport in AIAircraft::ProcessFlightplan()" << endl;
 847         //if (dep)
 848         //  cerr << "Departure " << dep->getId() << endl;
 849         //if (arr)
 850         //  cerr << "Arrival   " << arr->getId() << endl;
 851
 852     } else {
 853         double cruiseAlt = trafficRef->getCruiseAlt() * 100;
 854         //cerr << "Creating new leg using " << cruiseAlt << " as cruise altitude."<< endl;
 855
 856         fp->create (dep,
 857                     arr,
 858                     leg,
 859                     cruiseAlt, //(trafficRef->getCruiseAlt() * 100), // convert from FL to feet
 860                     trafficRef->getSpeed(),
 861                     _getLatitude(),
 862                     _getLongitude(),
 863                     false,
 864                     trafficRef->getRadius(),
 865                     trafficRef->getFlightType(),
 866                     acType,
 867                     company);
 868         //prev = fp->getPreviousWaypoint();
 869         //curr = fp->getCurrentWaypoint();
 870         //next = fp->getNextWaypoint();
 871         //cerr << "25" << endl;
 872         //if (next)
 873         //        {
 874         //  //cerr << "Next waypoint" << next->name << endl;
 875         //          fp->setLeadDistance(speed, tgt_heading, curr, next);
 876         //        }
 877         //cerr << "25.1" << endl;
 878         //if (curr->crossat > -1000.0) {
 879         //        //cerr << "25.1a" << endl;
 880         //        use_perf_vs = false;
 881         //
 882         //        tgt_vs = (curr->crossat - altitude_ft)/
 883         //          (fp->getDistanceToGo(pos.lat(), pos.lon(), curr)/6076.0/speed*60.0);
 884         //        //cerr << "25.1b" << endl;
 885         //        tgt_altitude_ft = curr->crossat;
 886         //} else {
 887         //        //cerr << "25.1c" << endl;
 888         //        use_perf_vs = true;
 889         //        //cerr << "25.1d" << endl;
 890         //        tgt_altitude_ft = prev->altitude;
 891         //        //cerr << "Setting target altitude : " <<tgt_altitude_ft << endl;
 892         // }
 893         //cerr << "26" << endl;
 894         //tgt_speed = prev->speed;
 895         //hdg_lock = alt_lock = true;
 896         //no_roll = prev->on_ground;
 897     }
 898     //else
 899     //{
 900     //delete entity.fp;
 901     //entity.fp = new FGAIFlightPlan(&entity,
 902     //                                 999,  // A hack
 903     //                                 trafficRef->getDepartureTime(),
 904     //                                 trafficRef->getDepartureAirport(),
 905     //                                 trafficRef->getArrivalAirport(),
 906     //                                 false,
 907     //                                 acType,
 908     //                                 company);
 909     //SetFlightPlan(entity.fp);
 910 }
 911
 912
 913 // Note: This code is copied from David Luff's AILocalTraffic
 914 // Warning - ground elev determination is CPU intensive
 915 // Either this function or the logic of how often it is called
 916 // will almost certainly change.
 917
 918 void FGAIAircraft::getGroundElev(double dt) {
 919     dt_elev_count += dt;
 920
 921     // Update minimally every three secs, but add some randomness
 922     // to prevent all IA objects doing this in synchrony
 923     if (dt_elev_count < (3.0) + (rand() % 10))
 924         return;
 925     else
 926        dt_elev_count = 0;
 927
 928     // Only do the proper hitlist stuff if we are within visible range of the viewer.
 929     if (!invisible) {
 930         double visibility_meters = fgGetDouble("/environment/visibility-m");
 931
 932         FGViewer* vw = globals->get_current_view();
 933         double course, distance;
 934
 935         SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
 936         SGWayPoint view (vw->getLongitude_deg(), vw->getLatitude_deg(), 0);
 937         view.CourseAndDistance(current, &course, &distance);
 938         if(distance > visibility_meters) {
 939             //aip.getSGLocation()->set_cur_elev_m(aptElev);
 940             return;
 941         }
 942
 943         // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
 944         double range = 500.0;
 945         if (!globals->get_tile_mgr()->scenery_available(pos.getLatitudeDeg(), pos.getLongitudeDeg(), range)) {
 946             // Try to shedule tiles for that position.
 947             globals->get_tile_mgr()->update( aip.getSGLocation(), range );
 948         }
 949
 950         // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
 951         double alt;
 952         if (globals->get_scenery()->get_elevation_m(pos.getLatitudeDeg(), pos.getLongitudeDeg(), 20000.0, alt, 0))
 953             tgt_altitude_ft = alt * SG_METER_TO_FEET;
 954
 955         //cerr << "Target altitude : " << tgt_altitude_ft << endl;
 956         // if (globals->get_scenery()->get_elevation_m(pos.lat(), pos.lon(),
 957         //                                            20000.0, alt))
 958         //    tgt_altitude_ft = alt * SG_METER_TO_FEET;
 959         //cerr << "Target altitude : " << tgt_altitude_ft << endl;
 960     }
 961 }
 962
 963
 964 void FGAIAircraft::setCallSign(const string& s) {
 965     callsign = s;
 966 }
 967
 968
 969 void FGAIAircraft::setTACANChannelID(const string& id) {
 970     TACAN_channel_id = id;
 971 }
 972
 973
 974 void FGAIAircraft::doGroundAltitude() {
 975    if (fabs(altitude_ft - (tgt_altitude_ft+groundOffset)) > 1000.0)
 976        altitude_ft = (tgt_altitude_ft + groundOffset);
 977    else
 978       altitude_ft += 0.1 * ((tgt_altitude_ft+groundOffset) - altitude_ft);
 979 }
 980
 981
 982 void FGAIAircraft::announcePositionToController()
 983 {
 984   if (trafficRef) {
 985     //FGTaxiRoute *taxiRoute = fp->getTaxiRoute();
 986
 987     int leg = fp->getLeg();
 988
 989     //if (fp->getCurrentWaypoint()->routeIndex != 0) {
 990       //char buffer[10];
 991       //snprintf (buffer, 10, "%d", node);
 992       // Note that leg was been incremented after creating the current leg, so we should use
 993       // leg numbers here that are one higher than the number that is used to create the leg
 994       //
 995       switch (leg) {
 996       case 3: // Taxiing to runway
 997         if (trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork()->exists())
 998           controller = trafficRef->getDepartureAirport()->getDynamics()->getGroundNetwork();
 999         break;
1000       case 4: //Take off tower controller
1001         if (trafficRef->getDepartureAirport()->getDynamics())
1002           {
1003             controller = trafficRef->getDepartureAirport()->getDynamics()->getTowerController();
1004             //if (trafficRef->getDepartureAirport()->getId() == "EHAM") {
1005             //cerr << trafficRef->getCallSign() << " at runway " << fp->getRunway() << "Ready for departure "
1006             //   << trafficRef->getFlightType() << " to " << trafficRef->getArrivalAirport()->getId() << endl;
1007             //  if (controller == 0) {
1008             //cerr << "Error in assigning controller at " << trafficRef->getDepartureAirport()->getId() << endl;
1009                 //}
1010
1011           }
1012         else {
1013           cerr << "Error: Could not find Dynamics at airport : " << trafficRef->getDepartureAirport()->getId() << endl;
1014         }
1015         break;
1016       case 9: // Taxiing for parking
1017         if (trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork()->exists())
1018           controller = trafficRef->getArrivalAirport()->getDynamics()->getGroundNetwork();
1019         break;
1020       default:
1021         controller = 0;
1022         break;
1023       }
1024
1025     if ((controller != prevController) && (prevController != 0)) {
1026       prevController->signOff(getID());
1027       string callsign =  trafficRef->getCallSign();
1028       if ( trafficRef->getHeavy())
1029         callsign += "Heavy";
1030       switch (leg) {
1031       case 3:
1032         cerr << callsign << " ready to taxi to runway " << fp->getRunway() << endl;
1033         break;
1034       case 4:
1035         cerr << callsign << " at runway " << fp->getRunway() << "Ready for take-off. "
1036              << trafficRef->getFlightRules() << " to " << trafficRef->getArrivalAirport()->getId()
1037              << "(" << trafficRef->getArrivalAirport()->getName() << ")."<< endl;
1038       }
1039     }
1040     prevController = controller;
1041     if (controller) {
1042       controller->announcePosition(getID(), fp, fp->getCurrentWaypoint()->routeIndex,
1043                            _getLatitude(), _getLongitude(), hdg, speed, altitude_ft,
1044                                    trafficRef->getRadius(), leg);
1045     }
1046   }
1047 }
1048
1049
1050 void FGAIAircraft::processATC(FGATCInstruction instruction)
1051 {
1052   //cerr << "Processing ATC instruction (not Implimented yet)" << endl;
1053   if (instruction.getHoldPattern   ()) {
1054   }
1055
1056   // Hold Position
1057   if (instruction.getHoldPosition  ()) {
1058     if (!holdPos) {
1059       if (trafficRef)
1060         cerr << trafficRef->getCallSign() << "Holding Position " << endl;
1061       holdPos = true;
1062     }
1063     AccelTo(0.25);
1064   } else {
1065     if (holdPos) {
1066       if (trafficRef)
1067         cerr << trafficRef->getCallSign() << " Resuming Taxi " << endl;
1068       holdPos = false;
1069     }
1070     // Change speed Instruction. This can only be excecuted when there is no
1071     // Hold position instruction.
1072     if (instruction.getChangeSpeed   ()) {
1073       AccelTo(instruction.getSpeed());
1074     }else {
1075       if (fp) AccelTo(fp->getPreviousWaypoint()->speed);
1076     }
1077   }
1078   if (instruction.getChangeHeading ()) {
1079     hdg_lock = false;
1080     TurnTo(instruction.getHeading());
1081   } else {
1082     if (fp) {hdg_lock = true;}
1083   }
1084   if (instruction.getChangeAltitude()) {
1085   }
1086
1087 }