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    static string tempReg;
  47 //
  48 // accel, decel, climb_rate, descent_rate, takeoff_speed, climb_speed,
  49 // cruise_speed, descent_speed, land_speed
  50 //
  51 const FGAIAircraft::PERF_STRUCT FGAIAircraft::settings[] = {
  52     // light aircraft
  53     {2.0, 2.0,  450.0, 1000.0,  70.0,  80.0, 100.0,  80.0,  60.0},
  54     // ww2_fighter
  55     {4.0, 2.0, 3000.0, 1500.0, 110.0, 180.0, 250.0, 200.0, 100.0},
  56     // jet_transport
  57     {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0},
  58     // jet_fighter
  59     {7.0, 3.0, 4000.0, 2000.0, 150.0, 350.0, 500.0, 350.0, 150.0},
  60     // tanker
  61     {5.0, 2.0, 3000.0, 1500.0, 140.0, 300.0, 430.0, 300.0, 130.0}
  62 };
  63
  64
  65 FGAIAircraft::FGAIAircraft(FGAISchedule *ref) :
  66     FGAIBase(otAircraft)
  67 {
  68     trafficRef = ref;
  69     if (trafficRef)
  70         groundOffset = trafficRef->getGroundOffset();
  71     else
  72         groundOffset = 0;
  73
  74     fp = 0;
  75     dt_count = 0;
  76     dt_elev_count = 0;
  77     use_perf_vs = true;
  78     isTanker = false;
  79
  80     // set heading and altitude locks
  81     hdg_lock = false;
  82     alt_lock = false;
  83     roll = 0;
  84     headingChangeRate = 0.0;
  85 }
  86
  87
  88 FGAIAircraft::~FGAIAircraft() {
  89     //delete fp;
  90 }
  91
  92
  93 void FGAIAircraft::readFromScenario(SGPropertyNode* scFileNode) {
  94     if (!scFileNode)
  95         return;
  96
  97     FGAIBase::readFromScenario(scFileNode);
  98
  99     setPerformance(scFileNode->getStringValue("class", "jet_transport"));
 100     setFlightPlan(scFileNode->getStringValue("flightplan"),
 101                   scFileNode->getBoolValue("repeat", false));
 102     setCallSign(scFileNode->getStringValue("callsign"));
 103     setTACANChannelID(scFileNode->getStringValue("TACAN-channel-ID"));
 104 }
 105
 106
 107 bool FGAIAircraft::init() {
 108     //refuel_node = fgGetNode("systems/refuel/contact", true);
 109     return FGAIBase::init();
 110 }
 111
 112
 113 void FGAIAircraft::bind() {
 114     FGAIBase::bind();
 115
 116     props->tie("controls/gear/gear-down",
 117                SGRawValueMethods<FGAIAircraft,bool>(*this,
 118                                               &FGAIAircraft::_getGearDown));
 119     props->tie("refuel/contact", SGRawValuePointer<bool>(&contact));
 120     props->setStringValue("callsign", callsign.c_str());
 121     props->setStringValue("navaids/tacan/channel-ID", TACAN_channel_id.c_str());
 122     props->setBoolValue("tanker",isTanker);
 123 }
 124
 125
 126 void FGAIAircraft::unbind() {
 127     FGAIBase::unbind();
 128
 129     props->untie("controls/gear/gear-down");
 130     props->untie("refuel/contact");
 131 }
 132
 133
 134 void FGAIAircraft::update(double dt) {
 135     FGAIBase::update(dt);
 136     Run(dt);
 137     Transform();
 138 }
 139
 140
 141 void FGAIAircraft::setPerformance(const std::string& acclass) {
 142     if (acclass == "light") {
 143         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::LIGHT]);
 144     } else if (acclass == "ww2_fighter") {
 145         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::WW2_FIGHTER]);
 146     } else if (acclass == "jet_transport") {
 147         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 148     } else if (acclass == "jet_fighter") {
 149         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_FIGHTER]);
 150     } else if (acclass == "tanker") {
 151         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 152         SetTanker(true);
 153     } else {
 154         SetPerformance(&FGAIAircraft::settings[FGAIAircraft::JET_TRANSPORT]);
 155     }
 156 }
 157
 158
 159 void FGAIAircraft::SetPerformance(const PERF_STRUCT *ps) {
 160
 161    performance = ps;
 162 }
 163
 164
 165 void FGAIAircraft::Run(double dt) {
 166
 167     FGAIAircraft::dt = dt;
 168
 169     if (fp) {
 170         time_t now = time(NULL) + fgGetLong("/sim/time/warp");
 171         ProcessFlightPlan(dt, now);
 172         if (now < fp->getStartTime()) {
 173             // Do execute Ground elev for inactive aircraft, so they
 174             // Are repositioned to the correct ground altitude when the user flies within visibility range.
 175             if (no_roll) {
 176                 Transform();       // make sure aip is initialized.
 177                 getGroundElev(dt); // make sure it's exectuted first time around, so force a large dt value
 178                 //getGroundElev(dt); // Need to do this twice.
 179                 //cerr << trafficRef->getRegistration() << " Setting altitude to " << tgt_altitude;
 180                 doGroundAltitude();
 181                 //cerr << " Actual altitude " << altitude << endl;
 182                 // Transform();
 183                 pos.setElevationFt(altitude);
 184             }
 185             return;
 186         }
 187     } else {
 188         // no flight plan, update target heading, speed, and altitude
 189         // from control properties.  These default to the initial
 190         // settings in the config file, but can be changed "on the
 191         // fly".
 192
 193         string lat_mode = props->getStringValue("controls/flight/lateral-mode");
 194         if ( lat_mode == "roll" ) {
 195             double angle
 196                 = props->getDoubleValue("controls/flight/target-roll" );
 197             RollTo( angle );
 198         } else {
 199              double angle
 200                 = props->getDoubleValue("controls/flight/target-hdg" );
 201             TurnTo( angle );
 202         }
 203
 204         string lon_mode
 205             = props->getStringValue("controls/flight/longitude-mode");
 206         if ( lon_mode == "alt" ) {
 207             double alt = props->getDoubleValue("controls/flight/target-alt" );
 208             ClimbTo( alt );
 209         } else {
 210             double angle
 211                 = props->getDoubleValue("controls/flight/target-pitch" );
 212             PitchTo( angle );
 213         }
 214
 215         AccelTo( props->getDoubleValue("controls/flight/target-spd" ) );
 216     }
 217
 218     double turn_radius_ft;
 219     double turn_circum_ft;
 220     double speed_north_deg_sec;
 221     double speed_east_deg_sec;
 222     double dist_covered_ft;
 223     double alpha;
 224
 225     // adjust speed
 226     double speed_diff; //= tgt_speed - speed;
 227     if (!no_roll) {
 228         speed_diff = tgt_speed - speed;
 229     } else {
 230         speed_diff = groundTargetSpeed - speed;
 231     }
 232     if (fabs(speed_diff) > 0.2) {
 233         if (speed_diff > 0.0)
 234             speed += performance->accel * dt;
 235         if (speed_diff < 0.0) {
 236             if (no_roll) { // was (!no_roll) but seems more logical this way (ground brakes).
 237                 speed -= performance->decel * dt * 3;
 238             } else {
 239                 speed -= performance->decel * dt;
 240             }
 241         }
 242     }
 243
 244     // convert speed to degrees per second
 245     speed_north_deg_sec = cos( hdg / SG_RADIANS_TO_DEGREES )
 246                           * speed * 1.686 / ft_per_deg_lat;
 247     speed_east_deg_sec  = sin( hdg / SG_RADIANS_TO_DEGREES )
 248                           * speed * 1.686 / ft_per_deg_lon;
 249
 250     // set new position
 251     pos.setLatitudeDeg( pos.getLatitudeDeg() + speed_north_deg_sec * dt);
 252     pos.setLongitudeDeg( pos.getLongitudeDeg() + speed_east_deg_sec * dt);
 253     //if (!(finite(pos.lat()) && finite(pos.lon())))
 254     //  {
 255     //    cerr << "Position is not finite" << endl;
 256     //    cerr << "speed = " << speed << endl;
 257     //    cerr << "dt" << dt << endl;
 258     //    cerr << "heading " << hdg << endl;
 259     //    cerr << "speed east " << speed_east_deg_sec << endl;
 260     //    cerr << "speed nrth " << speed_north_deg_sec << endl;
 261     //    cerr << "deg_lat    " << ft_per_deg_lat << endl;
 262     //    cerr << "deg_lon    " << ft_per_deg_lon << endl;
 263     //  }
 264
 265     // adjust heading based on current bank angle
 266     if (roll == 0.0)
 267         roll = 0.01;
 268
 269     if (roll != 0.0) {
 270         // double turnConstant;
 271         //if (no_roll)
 272         //  turnConstant = 0.0088362;
 273         //else
 274         //  turnConstant = 0.088362;
 275         // If on ground, calculate heading change directly
 276         if (no_roll) {
 277             double headingDiff = fabs(hdg-tgt_heading);
 278
 279             if (headingDiff > 180)
 280                 headingDiff = fabs(headingDiff - 360);
 281
 282             groundTargetSpeed = tgt_speed - (tgt_speed * (headingDiff/45));
 283             if (sign(groundTargetSpeed) != sign(tgt_speed))
 284                 groundTargetSpeed = 0.21 * sign(tgt_speed); // to prevent speed getting stuck in 'negative' mode
 285
 286             if (headingDiff > 30.0) {
 287                 headingChangeRate += dt * sign(roll); // invert if pushed backward
 288                 // Print some debug statements to find out why aircraft may get stuck
 289                 // forever turning
 290                 //if (trafficRef->getDepartureAirport()->getId() == string("EHAM")) {
 291                 //    cerr << "Turning : " << trafficRef->getRegistration()
 292                 //    cerr <<  " Speed = " << speed << " Heading " << hdg
 293                 //         << " Target Heading " << tgt_heading
 294                 //         << " Lead Distance " <<  fp->getLeadDistance()
 295                 //         << " Distance to go "
 296                 //         << fp->getDistanceToGo(pos.lat(), pos.lon(), fp->getCurrentWaypoint())
 297                 //         << "waypoint name " << fp->getCurrentWaypoint()->name
 298                 //         << endl;
 299                 //}
 300                 if (headingChangeRate > 30)
 301                     headingChangeRate = 30;
 302                 else if (headingChangeRate < -30)
 303                     headingChangeRate = -30;
 304
 305             } else {
 306                 if (fabs(headingChangeRate) > headingDiff)
 307                     headingChangeRate = headingDiff*sign(roll);
 308                 else
 309                     headingChangeRate += dt * sign(roll);
 310             }
 311             hdg += headingChangeRate * dt;
 312             //cerr << "On ground. Heading: " << hdg << ". Target Heading: " << tgt_heading
 313             //     << ". Target speed: " << groundTargetSpeed << ". heading change rate"
 314             //     << headingChangeRate << endl;
 315
 316         } else {
 317             if (fabs(speed) > 1.0) {
 318                 turn_radius_ft = 0.088362 * speed * speed
 319                         / tan( fabs(roll) / SG_RADIANS_TO_DEGREES );
 320             } else {
 321                 turn_radius_ft = 1.0; // Check if turn_radius_ft == 0; this might lead to a division by 0.
 322             }
 323             turn_circum_ft = SGD_2PI * turn_radius_ft;
 324             dist_covered_ft = speed * 1.686 * dt;
 325             alpha = dist_covered_ft / turn_circum_ft * 360.0;
 326             hdg += alpha * sign(roll);
 327         }
 328         while ( hdg > 360.0 ) {
 329             hdg -= 360.0;
 330             spinCounter++;
 331         }
 332         while ( hdg < 0.0) {
 333             hdg += 360.0;
 334             spinCounter--;
 335         }
 336     }
 337
 338
 339     // adjust target bank angle if heading lock engaged
 340     if (hdg_lock) {
 341         double bank_sense = 0.0;
 342         double diff = fabs(hdg - tgt_heading);
 343         if (diff > 180)
 344             diff = fabs(diff - 360);
 345
 346         double sum = hdg + diff;
 347         if (sum > 360.0)
 348             sum -= 360.0;
 349         if (fabs(sum - tgt_heading) < 1.0) {
 350             bank_sense = 1.0;   // right turn
 351         } else {
 352             bank_sense = -1.0;  // left turn
 353         }
 354         if (diff < 30) {
 355             tgt_roll = diff * bank_sense;
 356         } else {
 357             tgt_roll = 30.0 * bank_sense;
 358         }
 359         if ((fabs((double) spinCounter) > 1) && (diff > 30)) {
 360             tgt_speed *= 0.999; // Ugly hack: If aircraft get stuck, they will continually spin around.
 361             // The only way to resolve this is to make them slow down.
 362             //if (tempReg.empty())
 363             //  tempReg = trafficRef->getRegistration();
 364             //if (trafficRef->getRegistration() == tempReg) {
 365             //    cerr << trafficRef->getRegistration()
 366             //         << " appears to be spinning: " << spinCounter << endl
 367             //         << " speed          " << speed << endl
 368             //         << " heading        " << hdg << endl
 369             //         << " lead distance  " << fp->getLeadDistance() << endl
 370             //         << " waypoint       " << fp->getCurrentWaypoint()->name
 371             //         << " target heading " << tgt_heading << endl
 372             //         << " lead in angle  " << fp->getLeadInAngle()<< endl
 373             //         << " roll           " << roll << endl
 374             //         << " target_roll    " << tgt_roll << endl;
 375             //}
 376         }
 377     }
 378
 379     // adjust bank angle, use 9 degrees per second
 380     double bank_diff = tgt_roll - roll;
 381     if (fabs(bank_diff) > 0.2) {
 382         if (bank_diff > 0.0)
 383             roll += 9.0 * dt;
 384
 385         if (bank_diff < 0.0)
 386             roll -= 9.0 * dt;
 387         //while (roll > 180) roll -= 360;
 388         //while (roll < 180) roll += 360;
 389     }
 390
 391     // adjust altitude (meters) based on current vertical speed (fpm)
 392     altitude += vs / 60.0 * dt;
 393     pos.setElevationFt(altitude);
 394     double altitude_ft = altitude;
 395
 396     // adjust target Altitude, based on ground elevation when on ground
 397     if (no_roll) {
 398         getGroundElev(dt);
 399         doGroundAltitude();
 400     } else {
 401         // find target vertical speed if altitude lock engaged
 402         if (alt_lock && use_perf_vs) {
 403             if (altitude_ft < tgt_altitude) {
 404                 tgt_vs = tgt_altitude - altitude_ft;
 405                 if (tgt_vs > performance->climb_rate)
 406                     tgt_vs = performance->climb_rate;
 407             } else {
 408                 tgt_vs = tgt_altitude - altitude_ft;
 409                 if (tgt_vs  < (-performance->descent_rate))
 410                     tgt_vs = -performance->descent_rate;
 411             }
 412         }
 413
 414         if (alt_lock && !use_perf_vs) {
 415             double max_vs = 4*(tgt_altitude - altitude);
 416             double min_vs = 100;
 417             if (tgt_altitude < altitude)
 418                 min_vs = -100.0;
 419             if ((fabs(tgt_altitude - altitude) < 1500.0)
 420                     && (fabs(max_vs) < fabs(tgt_vs)))
 421                 tgt_vs = max_vs;
 422
 423             if (fabs(tgt_vs) < fabs(min_vs))
 424                 tgt_vs = min_vs;
 425         }
 426     }
 427     // adjust vertical speed
 428     double vs_diff = tgt_vs - vs;
 429     if (fabs(vs_diff) > 10.0) {
 430         if (vs_diff > 0.0) {
 431             vs += 900.0 * dt;
 432
 433             if (vs > tgt_vs)
 434                 vs = tgt_vs;
 435         } else {
 436             vs -= 400.0 * dt;
 437
 438            if (vs < tgt_vs)
 439                vs = tgt_vs;
 440         }
 441     }
 442
 443     // match pitch angle to vertical speed
 444     if (vs > 0) {
 445         pitch = vs * 0.005;
 446     } else {
 447         pitch = vs * 0.002;
 448     }
 449
 450     //###########################//
 451     // do calculations for radar //
 452     //###########################//
 453     double range_ft2 = UpdateRadar(manager);
 454
 455     //************************************//
 456     // Tanker code                        //
 457     //************************************//
 458
 459     if ( isTanker) {
 460         if ( (range_ft2 < 250.0 * 250.0) && (y_shift > 0.0)
 461                 && (elevation > 0.0) ) {
 462             //refuel_node->setBoolValue(true);
 463             contact = true;
 464         } else {
 465             //refuel_node->setBoolValue(false);
 466             contact = false;
 467         }
 468     } else {
 469         contact = false;
 470     }
 471 }
 472
 473
 474 void FGAIAircraft::AccelTo(double speed) {
 475     tgt_speed = speed;
 476 }
 477
 478
 479 void FGAIAircraft::PitchTo(double angle) {
 480     tgt_pitch = angle;
 481     alt_lock = false;
 482 }
 483
 484
 485 void FGAIAircraft::RollTo(double angle) {
 486     tgt_roll = angle;
 487     hdg_lock = false;
 488 }
 489
 490
 491 void FGAIAircraft::YawTo(double angle) {
 492     tgt_yaw = angle;
 493 }
 494
 495
 496 void FGAIAircraft::ClimbTo(double altitude) {
 497     tgt_altitude = altitude;
 498     alt_lock = true;
 499 }
 500
 501
 502 void FGAIAircraft::TurnTo(double heading) {
 503     tgt_heading = heading;
 504     hdg_lock = true;
 505 }
 506
 507
 508 double FGAIAircraft::sign(double x) {
 509     if ( x < 0.0 )
 510         return -1.0;
 511     else
 512         return 1.0;
 513 }
 514
 515
 516 void FGAIAircraft::setFlightPlan(const std::string& flightplan, bool repeat) {
 517     if (!flightplan.empty()) {
 518         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
 519         fp->setRepeat(repeat);
 520         SetFlightPlan(fp);
 521     }
 522 }
 523
 524
 525 void FGAIAircraft::SetFlightPlan(FGAIFlightPlan *f) {
 526     delete fp;
 527     fp = f;
 528 }
 529
 530
 531 void FGAIAircraft::ProcessFlightPlan( double dt, time_t now ) {
 532     bool eraseWaypoints;
 533     if (trafficRef) {
 534 //      FGAirport *arr;
 535 //      FGAirport *dep;
 536         eraseWaypoints = true;
 537 //      cerr << trafficRef->getRegistration();
 538 //      cerr << "Departure airport " << endl;
 539 //      dep = trafficRef->getDepartureAirport();
 540 //      if (dep)
 541 //          cerr << dep->getId() << endl;
 542 //      cerr << "Arrival   airport " << endl;
 543 //      arr = trafficRef->getArrivalAirport();
 544 //      if (arr)
 545 //          cerr << arr->getId() <<endl << endl;;
 546     } else
 547         eraseWaypoints = false;
 548
 549     //cerr << "Processing Flightplan" << endl;
 550     FGAIFlightPlan::waypoint* prev = 0; // the one behind you
 551     FGAIFlightPlan::waypoint* curr = 0; // the one ahead
 552     FGAIFlightPlan::waypoint* next = 0; // the next plus 1
 553     prev = fp->getPreviousWaypoint();
 554     curr = fp->getCurrentWaypoint();
 555     next = fp->getNextWaypoint();
 556     dt_count += dt;
 557
 558     if (!prev) {  //beginning of flightplan, do this initialization once
 559         //setBank(0.0);
 560         spinCounter = 0;
 561         tempReg = "";
 562         //prev_dist_to_go = HUGE;
 563         //cerr << "Before increment " << curr-> name << endl;
 564         fp->IncrementWaypoint(eraseWaypoints);
 565         //prev = fp->getPreviousWaypoint(); //first waypoint
 566         //curr = fp->getCurrentWaypoint();  //second waypoint
 567         //next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 568         //cerr << "After increment " << prev-> name << endl;
 569         if (!(fp->getNextWaypoint()) && trafficRef)
 570             loadNextLeg();
 571
 572         //cerr << "After load " << prev-> name << endl;
 573         prev = fp->getPreviousWaypoint(); //first waypoint
 574         curr = fp->getCurrentWaypoint();  //second waypoint
 575         next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 576         //cerr << "After load " << prev-> name << endl;
 577         setLatitude(prev->latitude);
 578         setLongitude(prev->longitude);
 579         setSpeed(prev->speed);
 580         setAltitude(prev->altitude);
 581
 582         if (prev->speed > 0.0)
 583             setHeading(fp->getBearing(prev->latitude, prev->longitude, curr));
 584         else
 585             setHeading(fp->getBearing(curr->latitude, curr->longitude, prev));
 586
 587         // If next doesn't exist, as in incrementally created flightplans for
 588         // AI/Trafficmanager created plans,
 589         // Make sure lead distance is initialized otherwise
 590         if (next)
 591             fp->setLeadDistance(speed, hdg, curr, next);
 592
 593         if (curr->crossat > -1000.0) { //use a calculated descent/climb rate
 594             use_perf_vs = false;
 595             tgt_vs = (curr->crossat - prev->altitude)
 596                     / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 597                     / 6076.0 / prev->speed*60.0);
 598             tgt_altitude = curr->crossat;
 599         } else {
 600             use_perf_vs = true;
 601             tgt_altitude = prev->altitude;
 602         }
 603         alt_lock = hdg_lock = true;
 604         no_roll = prev->on_ground;
 605         if (no_roll) {
 606             Transform();         // make sure aip is initialized.
 607             getGroundElev(60.1); // make sure it's exectuted first time around, so force a large dt value
 608             //getGroundElev(60.1); // Need to do this twice.
 609             //cerr << trafficRef->getRegistration() << " Setting altitude to " << tgt_altitude << endl;
 610             doGroundAltitude(); //(tgt_altitude);
 611         }
 612         prevSpeed = 0;
 613         //cout << "First waypoint:  " << prev->name << endl;
 614         //cout << "  Target speed:    " << tgt_speed << endl;
 615         //cout << "  Target altitude: " << tgt_altitude << endl;
 616         //cout << "  Target heading:  " << tgt_heading << endl << endl;
 617         //cerr << "Done Flightplan init" << endl;
 618         return;
 619     } // end of initialization
 620
 621     // let's only process the flight plan every 100 ms.
 622     if ((dt_count < 0.1) || (now < fp->getStartTime())) {
 623         //cerr  << "done fp dt" << endl;
 624         return;
 625     } else {
 626         dt_count = 0;
 627     }
 628     // check to see if we've reached the lead point for our next turn
 629     double dist_to_go = fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 630
 631     //cerr << "2" << endl;
 632     double lead_dist = fp->getLeadDistance();
 633     //cerr << " Distance : " << dist_to_go << ": Lead distance " << lead_dist << endl;
 634     // experimental: Use fabs, because speed can be negative (I hope) during push_back.
 635
 636     if (lead_dist < fabs(2*speed)) {
 637         lead_dist = fabs(2*speed);  //don't skip over the waypoint
 638         //cerr << "Extending lead distance to " << lead_dist << endl;
 639     }
 640 //  FGAirport * apt = trafficRef->getDepartureAirport();
 641 //  if ((dist_to_go > prev_dist_to_go) && trafficRef && apt) {
 642 //      if (apt->getId() == string("EHAM"))
 643 //          cerr << "Alert: " << trafficRef->getRegistration() << " is moving away from waypoint " << curr->name  << endl
 644 //               << "Target heading : " << tgt_heading << "act heading " << hdg << " Tgt speed : " << tgt_speed << endl
 645 //               << "Lead distance : " << lead_dist  << endl
 646 //               << "Distance to go: " << dist_to_go << endl;
 647 //  }
 648
 649     prev_dist_to_go = dist_to_go;
 650     //cerr << "2" << endl;
 651     //if (no_roll)
 652     //  lead_dist = 10.0;
 653     //cout << "Leg : " << (fp->getLeg()-1) << ". dist_to_go: " << dist_to_go << ",  lead_dist: "
 654     //     << lead_dist << ", tgt_speed " << tgt_speed << ", tgt_heading " << tgt_heading
 655     //     << " speed " << speed << " hdg " << hdg << ". Altitude "  << altitude << " TAget alt :"
 656     //     << tgt_altitude << endl;
 657
 658     if ( dist_to_go < lead_dist ) {
 659         //prev_dist_to_go = HUGE;
 660         // For traffic manager generated aircraft:
 661         // check if the aircraft flies of of user range. And adjust the
 662         // Current waypoint's elevation according to Terrain Elevation
 663         if (curr->finished) {  //end of the flight plan
 664             if (fp->getRepeat())
 665                 fp->restart();
 666             else
 667                 setDie(true);
 668
 669             //cerr << "Done die end of fp" << endl;
 670             return;
 671         }
 672
 673         // we've reached the lead-point for the waypoint ahead
 674         //cerr << "4" << endl;
 675         //cerr << "Situation after lead point" << endl;
 676         //cerr << "Prviious: " << prev->name << endl;
 677         //cerr << "Current : " << curr->name << endl;
 678         //cerr << "Next    : " << next->name << endl;
 679         if (next) {
 680             tgt_heading = fp->getBearing(curr, next);
 681             spinCounter = 0;
 682         }
 683
 684         fp->IncrementWaypoint(eraseWaypoints);
 685         if (!(fp->getNextWaypoint()) && trafficRef)
 686             loadNextLeg();
 687
 688         prev = fp->getPreviousWaypoint();
 689         curr = fp->getCurrentWaypoint();
 690         next = fp->getNextWaypoint();
 691
 692         // Now that we have incremented the waypoints, excute some traffic manager specific code
 693         // based on the name of the waypoint we just passed.
 694         if (trafficRef) {
 695             double userLatitude  = fgGetDouble("/position/latitude-deg");
 696             double userLongitude = fgGetDouble("/position/longitude-deg");
 697             double course, distance;
 698             SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
 699             SGWayPoint user (userLongitude, userLatitude, 0);
 700             user.CourseAndDistance(current, &course, &distance);
 701             if ((distance * SG_METER_TO_NM) > TRAFFICTOAIDIST) {
 702                 setDie(true);
 703                 //cerr << "done fp die out of range" << endl;
 704                 return;
 705             }
 706
 707             FGAirport * dep = trafficRef->getDepartureAirport();
 708             FGAirport * arr = trafficRef->getArrivalAirport();
 709             // At parking the beginning of the airport
 710             if (!( dep && arr)) {
 711                 setDie(true);
 712                 return;
 713             }
 714
 715             //if ((dep->getId() == string("EHAM") || (arr->getId() == string("EHAM")))) {
 716             //    cerr << trafficRef->getRegistration()
 717             //         << " Enroute from " << dep->getId()
 718             //         << " to "           << arr->getId()
 719             //         << " just crossed " << prev->name
 720             //         << " Assigned rwy     " << fp->getRunwayId()
 721             //         << " " << fp->getRunway() << endl;
 722             // }
 723             //if ((dep->getId() == string("EHAM")) && (prev->name == "park2")) {
 724             //    cerr << "Schiphol ground "
 725             //         << trafficRef->getCallSign();
 726             //    if (trafficRef->getHeavy())
 727             //        cerr << "Heavy";
 728             //    cerr << ", is type "
 729             //         << trafficRef->getAircraft()
 730             //         << " ready to go. IFR to "
 731             //         << arr->getId() <<endl;
 732             // }
 733
 734             if (prev->name == "park2")
 735                 dep->getDynamics()->releaseParking(fp->getGate());
 736
 737             // Some debug messages, specific to testing the Logical networks.
 738             // if ((arr->getId() == string("EHAM")) && (prev->name  == "Center")) {
 739             //     cerr << "Schiphol ground "
 740             //          << trafficRef->getRegistration() << " "
 741             //          << trafficRef->getCallSign();
 742             //     if (trafficRef->getHeavy())
 743             //         cerr << "Heavy";
 744             //     cerr << ", arriving from " << dep->getName() ;
 745             //     cerr << " landed runway "
 746             //          << fp->getRunway()
 747             //          << " request taxi to gate "
 748             //          << arr->getDynamics()->getParkingName(fp->getGate())
 749             //          << endl;
 750             // }
 751             if (prev->name == "END")
 752                 fp->setTime(trafficRef->getDepartureTime());
 753             //cerr << "5" << endl;
 754         }
 755
 756         if (next) {
 757             //cerr << "Current waypoint" << curr->name << endl;
 758             //cerr << "Next waypoint" << next->name << endl;
 759             fp->setLeadDistance(speed, tgt_heading, curr, next);
 760         }
 761
 762         //cerr << "5.1" << endl;
 763         if (!(prev->on_ground)) { // only update the tgt altitude from flightplan if not on the ground
 764             tgt_altitude = prev->altitude;
 765             if (curr->crossat > -1000.0) {
 766                 //cerr << "5.1a" << endl;
 767                 use_perf_vs = false;
 768                 tgt_vs = (curr->crossat - altitude) / (fp->getDistanceToGo(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr)
 769                         / 6076.0 / speed*60.0);
 770                 //cerr << "5.1b" << endl;
 771                 tgt_altitude = curr->crossat;
 772             } else {
 773                 //cerr << "5.1c" << endl;
 774                 use_perf_vs = true;
 775                 //cerr << "5.1d" << endl;
 776                 //cerr << "Setting target altitude : " <<tgt_altitude << endl;
 777             }
 778         }
 779         //cerr << "6" << endl;
 780         tgt_speed = prev->speed;
 781         hdg_lock = alt_lock = true;
 782         no_roll = prev->on_ground;
 783         //cout << "Crossing waypoint: " << prev->name << endl;
 784         //cout << "  Target speed:    " << tgt_speed << endl;
 785         //cout << "  Target altitude: " << tgt_altitude << endl;
 786         //cout << "  Target heading:  " << tgt_heading << endl << endl;
 787
 788     } else {
 789         double calc_bearing = fp->getBearing(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr);
 790         //cerr << "Bearing = " << calc_bearing << endl;
 791         if (speed < 0) {
 792             calc_bearing +=180;
 793             if (calc_bearing > 360)
 794                 calc_bearing -= 360;
 795         }
 796
 797         if (finite(calc_bearing)) {
 798             double hdg_error = calc_bearing - tgt_heading;
 799             if (fabs(hdg_error) > 1.0) {
 800                 TurnTo( calc_bearing );
 801             }
 802
 803         } else {
 804             cerr << "calc_bearing is not a finite number : "
 805                  << "Speed " << speed
 806                  << "pos : " << pos.getLatitudeDeg() << ", " << pos.getLongitudeDeg()
 807                  << "waypoint " << curr->latitude << ", " << curr->longitude << endl;
 808             cerr << "waypoint name " << curr->name;
 809             exit(1);  // FIXME
 810         }
 811
 812         double speed_diff = speed - prevSpeed;
 813         // Update the lead distance calculation if speed has changed sufficiently
 814         // to prevent spinning (hopefully);
 815         if (fabs(speed_diff) > 10) {
 816             prevSpeed = speed;
 817             fp->setLeadDistance(speed, tgt_heading, curr, next);
 818         }
 819
 820         //cerr << "Done Processing FlightPlan"<< endl;
 821     }
 822 }
 823
 824
 825 bool FGAIAircraft::_getGearDown() const {
 826     return ((props->getFloatValue("position/altitude-agl-ft") < 900.0)
 827             && (props->getFloatValue("velocities/airspeed-kt")
 828             < performance->land_speed*1.25));
 829 }
 830
 831
 832 void FGAIAircraft::loadNextLeg() {
 833     //delete fp;
 834     //time_t now = time(NULL) + fgGetLong("/sim/time/warp");
 835
 836     //FGAIModelEntity entity;
 837     //entity.m_class = "jet_transport";
 838     //entity.path = modelPath.c_str();
 839     //entity.flightplan = "none";
 840     //entity.latitude = _getLatitude();
 841     //entity.longitude = _getLongitude();
 842     //entity.altitude = trafficRef->getCruiseAlt() * 100; // convert from FL to feet
 843     //entity.speed = 450; // HACK ALERT
 844     //entity.fp = new FGAIFlightPlan(&entity, courseToDest, i->getDepartureTime(), dep, arr);
 845     int leg;
 846     if ((leg = fp->getLeg())  == 10) {
 847         trafficRef->next();
 848         leg = 1;
 849         fp->setLeg(leg);
 850         //cerr << "Resetting leg : " << leg << endl;
 851     }
 852     //leg++;
 853     //fp->setLeg(leg);
 854     //cerr << "Creating leg number : " << leg << endl;
 855     FGAirport *dep = trafficRef->getDepartureAirport();
 856     FGAirport *arr = trafficRef->getArrivalAirport();
 857     if (!(dep && arr)) {
 858         setDie(true);
 859         //cerr << "Failed to get airport in AIAircraft::ProcessFlightplan()" << endl;
 860         //if (dep)
 861         //  cerr << "Departure " << dep->getId() << endl;
 862         //if (arr)
 863         //  cerr << "Arrival   " << arr->getId() << endl;
 864
 865     } else {
 866         double cruiseAlt = trafficRef->getCruiseAlt() * 100;
 867         //cerr << "Creating new leg using " << cruiseAlt << " as cruise altitude."<< endl;
 868
 869         fp->create (dep,
 870                     arr,
 871                     leg,
 872                     cruiseAlt, //(trafficRef->getCruiseAlt() * 100), // convert from FL to feet
 873                     trafficRef->getSpeed(),
 874                     _getLatitude(),
 875                     _getLongitude(),
 876                     false,
 877                     trafficRef->getRadius(),
 878                     trafficRef->getFlightType(),
 879                     acType,
 880                     company);
 881         //prev = fp->getPreviousWaypoint();
 882         //curr = fp->getCurrentWaypoint();
 883         //next = fp->getNextWaypoint();
 884         //cerr << "25" << endl;
 885         //if (next)
 886         //        {
 887         //  //cerr << "Next waypoint" << next->name << endl;
 888         //          fp->setLeadDistance(speed, tgt_heading, curr, next);
 889         //        }
 890         //cerr << "25.1" << endl;
 891         //if (curr->crossat > -1000.0) {
 892         //        //cerr << "25.1a" << endl;
 893         //        use_perf_vs = false;
 894         //
 895         //        tgt_vs = (curr->crossat - altitude)/
 896         //          (fp->getDistanceToGo(pos.lat(), pos.lon(), curr)/6076.0/speed*60.0);
 897         //        //cerr << "25.1b" << endl;
 898         //        tgt_altitude = curr->crossat;
 899         //} else {
 900         //        //cerr << "25.1c" << endl;
 901         //        use_perf_vs = true;
 902         //        //cerr << "25.1d" << endl;
 903         //        tgt_altitude = prev->altitude;
 904         //        //cerr << "Setting target altitude : " <<tgt_altitude << endl;
 905         // }
 906         //cerr << "26" << endl;
 907         //tgt_speed = prev->speed;
 908         //hdg_lock = alt_lock = true;
 909         //no_roll = prev->on_ground;
 910     }
 911     //else
 912     //{
 913     //delete entity.fp;
 914     //entity.fp = new FGAIFlightPlan(&entity,
 915     //                                 999,  // A hack
 916     //                                 trafficRef->getDepartureTime(),
 917     //                                 trafficRef->getDepartureAirport(),
 918     //                                 trafficRef->getArrivalAirport(),
 919     //                                 false,
 920     //                                 acType,
 921     //                                 company);
 922     //SetFlightPlan(entity.fp);
 923 }
 924
 925
 926 // Note: This code is copied from David Luff's AILocalTraffic
 927 // Warning - ground elev determination is CPU intensive
 928 // Either this function or the logic of how often it is called
 929 // will almost certainly change.
 930
 931 void FGAIAircraft::getGroundElev(double dt) {
 932     dt_elev_count += dt;
 933
 934     // Update minimally every three secs, but add some randomness
 935     // to prevent all IA objects doing this in synchrony
 936     if (dt_elev_count < (3.0) + (rand() % 10))
 937         return;
 938     else
 939        dt_elev_count = 0;
 940
 941     // Only do the proper hitlist stuff if we are within visible range of the viewer.
 942     if (!invisible) {
 943         double visibility_meters = fgGetDouble("/environment/visibility-m");
 944
 945         FGViewer* vw = globals->get_current_view();
 946         double course, distance;
 947
 948         SGWayPoint current(pos.getLongitudeDeg(), pos.getLatitudeDeg(), 0);
 949         SGWayPoint view (vw->getLongitude_deg(), vw->getLatitude_deg(), 0);
 950         view.CourseAndDistance(current, &course, &distance);
 951         if(distance > visibility_meters) {
 952             //aip.getSGLocation()->set_cur_elev_m(aptElev);
 953             return;
 954         }
 955
 956         // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
 957         double range = 500.0;
 958         if (!globals->get_tile_mgr()->scenery_available(pos.getLatitudeDeg(), pos.getLongitudeDeg(), range)) {
 959             // Try to shedule tiles for that position.
 960             globals->get_tile_mgr()->update( aip.getSGLocation(), range );
 961         }
 962
 963         // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
 964         double alt;
 965         if (globals->get_scenery()->get_elevation_m(pos.getLatitudeDeg(), pos.getLongitudeDeg(), 20000.0, alt, 0))
 966             tgt_altitude = alt * SG_METER_TO_FEET;
 967
 968         //cerr << "Target altitude : " << tgt_altitude << endl;
 969         // if (globals->get_scenery()->get_elevation_m(pos.lat(), pos.lon(),
 970         //                                            20000.0, alt))
 971         //    tgt_altitude = alt * SG_METER_TO_FEET;
 972         //cerr << "Target altitude : " << tgt_altitude << endl;
 973     }
 974 }
 975
 976
 977 void FGAIAircraft::setCallSign(const string& s) {
 978     callsign = s;
 979 }
 980
 981
 982 void FGAIAircraft::setTACANChannelID(const string& id) {
 983     TACAN_channel_id = id;
 984 }
 985
 986
 987 void FGAIAircraft::doGroundAltitude() {
 988    if (fabs(altitude - (tgt_altitude+groundOffset)) > 1000.0)
 989        altitude = (tgt_altitude + groundOffset);
 990    else
 991       altitude += 0.1 * ((tgt_altitude+groundOffset) - altitude);
 992 }
 993