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