src/AIModel/AIShip.cxx

   1 // FGAIShip - FGAIBase-derived class creates an AI ship
   2 //
   3 // Written by David Culp, started October 2003.
   4 // with major amendments and additions by Vivian Meazza, 2004 - 2007
   5 //
   6 // This program is free software; you can redistribute it and/or
   7 // modify it under the terms of the GNU General Public License as
   8 // published by the Free Software Foundation; either version 2 of the
   9 // License, or (at your option) any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software
  18 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19
  20 #ifdef HAVE_CONFIG_H
  21 #  include <config.h>
  22 #endif
  23
  24 #ifdef _MSC_VER
  25 #  include <float.h>
  26 #  define finite _finite
  27 #elif defined(__sun) || defined(sgi)
  28 #  include <ieeefp.h>
  29 #endif
  30
  31 #include <math.h>
  32
  33 #include <simgear/sg_inlines.h>
  34 #include <simgear/math/sg_geodesy.hxx>
  35 #include <simgear/timing/sg_time.hxx>
  36 #include <simgear/math/sg_random.h>
  37
  38 #include <simgear/scene/util/SGNodeMasks.hxx>
  39 #include <Scenery/scenery.hxx>
  40
  41 #include "AIShip.hxx"
  42
  43
  44 FGAIShip::FGAIShip(object_type ot) :
  45 // allow HOT to be enabled
  46 FGAIBase(ot, true),
  47
  48
  49 _waiting(false),
  50 _new_waypoint(true),
  51 _tunnel(false),
  52 _initial_tunnel(false),
  53 _restart(false),
  54 _hdg_constant(0.01),
  55 _limit(100),
  56 _elevation_m(0),
  57 _elevation_ft(0),
  58 _tow_angle(0),
  59 _missed_count(0),
  60 _wp_range(0),
  61 _dt_count(0),
  62 _next_run(0),
  63 _roll_constant(0.001),
  64 _roll_factor(-0.0083335),
  65 _old_range(0),
  66 _range_rate(0),
  67 _missed_time_sec(30),
  68 _day(86400),
  69 _lead_angle(0),
  70 _xtrack_error(0),
  71 _curr_alt(0),
  72 _prev_alt(0),
  73 _until_time(""),
  74 _fp_init(false),
  75 _missed(false)
  76 {
  77         invisible = false;
  78 }
  79
  80 FGAIShip::~FGAIShip() {
  81 }
  82
  83 void FGAIShip::readFromScenario(SGPropertyNode* scFileNode) {
  84
  85     if (!scFileNode)
  86         return;
  87
  88     FGAIBase::readFromScenario(scFileNode);
  89
  90     setRudder(scFileNode->getFloatValue("rudder", 0.0));
  91     setName(scFileNode->getStringValue("name", "Titanic"));
  92     setRadius(scFileNode->getDoubleValue("turn-radius-ft", 2000));
  93     std::string flightplan = scFileNode->getStringValue("flightplan");
  94     setRepeat(scFileNode->getBoolValue("repeat", false));
  95     setRestart(scFileNode->getBoolValue("restart", false));
  96     setStartTime(scFileNode->getStringValue("time", ""));
  97     setLeadAngleGain(scFileNode->getDoubleValue("lead-angle-gain", 1.5));
  98     setLeadAngleLimit(scFileNode->getDoubleValue("lead-angle-limit-deg", 15));
  99     setLeadAngleProp(scFileNode->getDoubleValue("lead-angle-proportion", 0.75));
 100     setRudderConstant(scFileNode->getDoubleValue("rudder-constant", 0.5));
 101     setFixedTurnRadius(scFileNode->getDoubleValue("fixed-turn-radius-ft", 500));
 102     setSpeedConstant(scFileNode->getDoubleValue("speed-constant", 0.5));
 103     setSMPath(scFileNode->getStringValue("submodel-path", ""));
 104
 105     if (!flightplan.empty()) {
 106         SG_LOG(SG_GENERAL, SG_ALERT, "getting flightplan: " << _name );
 107
 108         FGAIFlightPlan* fp = new FGAIFlightPlan(flightplan);
 109         setFlightPlan(fp);
 110     }
 111
 112 }
 113
 114 bool FGAIShip::init(bool search_in_AI_path) {
 115     prev = 0; // the one behind you
 116     curr = 0; // the one ahead
 117     next = 0; // the next plus 1
 118
 119     props->setStringValue("name", _name.c_str());
 120     props->setStringValue("waypoint/name-prev", _prev_name.c_str());
 121     props->setStringValue("waypoint/name-curr", _curr_name.c_str());
 122     props->setStringValue("waypoint/name-next", _next_name.c_str());
 123     props->setStringValue("submodels/path", _path.c_str());
 124     props->setStringValue("waypoint/start-time", _start_time.c_str());
 125     props->setStringValue("waypoint/wait-until-time", _until_time.c_str());
 126
 127     _hdg_lock = false;
 128     _rudder = 0.0;
 129     no_roll = false;
 130
 131     _rd_turn_radius_ft = _sp_turn_radius_ft = turn_radius_ft;
 132
 133     if (fp)
 134         _fp_init = initFlightPlan();
 135
 136     return FGAIBase::init(search_in_AI_path);
 137 }
 138
 139 void FGAIShip::bind() {
 140     FGAIBase::bind();
 141
 142     props->tie("surface-positions/rudder-pos-deg",
 143         SGRawValuePointer<float>(&_rudder));
 144     props->tie("controls/heading-lock",
 145         SGRawValuePointer<bool>(&_hdg_lock));
 146     props->tie("controls/tgt-speed-kts",
 147         SGRawValuePointer<double>(&tgt_speed));
 148     props->tie("controls/tgt-heading-degs",
 149         SGRawValuePointer<double>(&tgt_heading));
 150     props->tie("controls/constants/rudder",
 151         SGRawValuePointer<double>(&_rudder_constant));
 152     props->tie("controls/constants/roll-factor",
 153         SGRawValuePointer<double>(&_roll_factor));
 154     props->tie("controls/constants/roll",
 155         SGRawValuePointer<double>(&_roll_constant));
 156     props->tie("controls/constants/rudder",
 157         SGRawValuePointer<double>(&_rudder_constant));
 158     props->tie("controls/constants/speed",
 159         SGRawValuePointer<double>(&_speed_constant));
 160     props->tie("waypoint/range-nm",
 161         SGRawValuePointer<double>(&_wp_range));
 162     props->tie("waypoint/brg-deg",
 163         SGRawValuePointer<double>(&_course));
 164     props->tie("waypoint/rangerate-nm-sec",
 165         SGRawValuePointer<double>(&_range_rate));
 166     props->tie("waypoint/new",
 167         SGRawValuePointer<bool>(&_new_waypoint));
 168     props->tie("waypoint/missed",
 169         SGRawValuePointer<bool>(&_missed));
 170     props->tie("waypoint/missed-count-sec",
 171         SGRawValuePointer<double>(&_missed_count));
 172     props->tie("waypoint/missed-range-nm",
 173         SGRawValuePointer<double>(&_missed_range));
 174     props->tie("waypoint/missed-time-sec",
 175         SGRawValuePointer<double>(&_missed_time_sec));
 176     props->tie("waypoint/wait-count-sec",
 177         SGRawValuePointer<double>(&_wait_count));
 178     props->tie("waypoint/xtrack-error-ft",
 179         SGRawValuePointer<double>(&_xtrack_error));
 180     props->tie("waypoint/waiting",
 181         SGRawValuePointer<bool>(&_waiting));
 182     props->tie("waypoint/lead-angle-deg",
 183         SGRawValuePointer<double>(&_lead_angle));
 184     props->tie("waypoint/tunnel",
 185         SGRawValuePointer<bool>(&_tunnel));
 186     props->tie("waypoint/alt-curr-m",
 187         SGRawValuePointer<double>(&_curr_alt));
 188     props->tie("waypoint/alt-prev-m",
 189         SGRawValuePointer<double>(&_prev_alt));
 190     props->tie("submodels/serviceable",
 191         SGRawValuePointer<bool>(&_serviceable));
 192     props->tie("controls/turn-radius-ft",
 193         SGRawValuePointer<double>(&turn_radius_ft));
 194     props->tie("controls/turn-radius-corrected-ft",
 195         SGRawValuePointer<double>(&_rd_turn_radius_ft));
 196     props->tie("controls/constants/lead-angle/gain",
 197         SGRawValuePointer<double>(&_lead_angle_gain));
 198     props->tie("controls/constants/lead-angle/limit-deg",
 199         SGRawValuePointer<double>(&_lead_angle_limit));
 200     props->tie("controls/constants/lead-angle/proportion",
 201         SGRawValuePointer<double>(&_proportion));
 202     props->tie("controls/fixed-turn-radius-ft",
 203         SGRawValuePointer<double>(&_fixed_turn_radius));
 204     props->tie("controls/restart",
 205         SGRawValuePointer<bool>(&_restart));
 206     props->tie("velocities/speed-kts",
 207                 SGRawValuePointer<double>(&speed));
 208 }
 209
 210 void FGAIShip::unbind() {
 211     FGAIBase::unbind();
 212     props->untie("surface-positions/rudder-pos-deg");
 213     props->untie("controls/heading-lock");
 214     props->untie("controls/tgt-speed-kts");
 215     props->untie("controls/tgt-heading-degs");
 216     props->untie("controls/constants/roll");
 217     props->untie("controls/constants/rudder");
 218     props->untie("controls/constants/roll-factor");
 219     props->untie("controls/constants/speed");
 220     props->untie("waypoint/range-nm");
 221     props->untie("waypoint/range-brg-deg");
 222     props->untie("waypoint/rangerate-nm-sec");
 223     props->untie("waypoint/new");
 224     props->untie("waypoint/missed");
 225     props->untie("waypoint/missed-count-sec");
 226     props->untie("waypoint/missed-time-sec");
 227     props->untie("waypoint/missed-range");
 228     props->untie("waypoint/wait-count-sec");
 229     props->untie("waypoint/lead-angle-deg");
 230     props->untie("waypoint/xtrack-error-ft");
 231     props->untie("waypoint/waiting");
 232     props->untie("waypoint/tunnel");
 233     props->untie("waypoint/alt-curr-m");
 234     props->untie("waypoint/alt-prev-m");
 235     props->untie("submodels/serviceable");
 236     props->untie("controls/turn-radius-ft");
 237     props->untie("controls/turn-radius-corrected-ft");
 238     props->untie("controls/constants/lead-angle/gain");
 239     props->untie("controls/constants/lead-angle/limit-deg");
 240     props->untie("controls/constants/lead-angle/proportion");
 241     props->untie("controls/fixed-turn-radius-ft");
 242     props->untie("controls/constants/speed");
 243     props->untie("controls/restart");
 244     props->untie("velocities/speed-kts");
 245
 246 }
 247 void FGAIShip::update(double dt) {
 248     //SG_LOG(SG_GENERAL, SG_ALERT, "updating Ship: " << _name <<hdg<<pitch<<roll);
 249     // For computation of rotation speeds we just use finite differences here.
 250     // That is perfectly valid since this thing is not driven by accelerations
 251     // but by just apply discrete changes at its velocity variables.
 252     // Update the velocity information stored in those nodes.
 253     // Transform that one to the horizontal local coordinate system.
 254     SGQuatd ec2hl = SGQuatd::fromLonLat(pos);
 255     // The orientation of the ship wrt the horizontal local frame
 256     SGQuatd hl2body = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 257     // and postrotate the orientation of the AIModel wrt the horizontal
 258     // local frame
 259     SGQuatd ec2body = ec2hl*hl2body;
 260     // The cartesian position of the ship in the wgs84 world
 261     SGVec3d cartPos = SGVec3d::fromGeod(pos);
 262
 263     // The simulation time this transform is meant for
 264     aip.setReferenceTime(globals->get_sim_time_sec());
 265
 266     // Compute the velocity in m/s in the body frame
 267     aip.setBodyLinearVelocity(SGVec3d(0.51444444*speed, 0, 0));
 268
 269     FGAIBase::update(dt);
 270     Run(dt);
 271     Transform();
 272     if (fp)
 273         setXTrackError();
 274
 275     // Only change these values if we are able to compute them safely
 276     if (SGLimits<double>::min() < dt) {
 277         // Now here is the finite difference ...
 278
 279         // Transform that one to the horizontal local coordinate system.
 280         SGQuatd ec2hlNew = SGQuatd::fromLonLat(pos);
 281         // compute the new orientation
 282         SGQuatd hl2bodyNew = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 283         // The rotation difference
 284         SGQuatd dOr = inverse(ec2body)*ec2hlNew*hl2bodyNew;
 285         SGVec3d dOrAngleAxis;
 286         dOr.getAngleAxis(dOrAngleAxis);
 287         // divided by the time difference provides a rotation speed vector
 288         dOrAngleAxis /= dt;
 289
 290         aip.setBodyAngularVelocity(dOrAngleAxis);
 291     }
 292 }
 293
 294 void FGAIShip::Run(double dt) {
 295     if (_fp_init)
 296         ProcessFlightPlan(dt);
 297
 298     string type = getTypeString();
 299
 300     double alpha;
 301     double rudder_limit;
 302     double raw_roll;
 303
 304     // adjust speed
 305     double speed_diff = tgt_speed - speed;
 306
 307     if (fabs(speed_diff) > 0.1) {
 308
 309         if (speed_diff > 0.0)
 310             speed += _speed_constant * dt;
 311
 312         if (speed_diff < 0.0)
 313             speed -= _speed_constant * dt;
 314
 315     }
 316
 317     // do not allow unreasonable speeds
 318     SG_CLAMP_RANGE(speed, -_limit * 0.75, _limit);
 319
 320     // convert speed to degrees per second
 321     speed_north_deg_sec = cos(hdg / SGD_RADIANS_TO_DEGREES)
 322         * speed * 1.686 / ft_per_deg_lat;
 323     speed_east_deg_sec = sin(hdg / SGD_RADIANS_TO_DEGREES)
 324         * speed * 1.686 / ft_per_deg_lon;
 325
 326     // set new position
 327     //cout << _name << " " << type << " run: " << _elevation_m << " " <<_elevation_ft << endl;
 328     pos.setLatitudeDeg(pos.getLatitudeDeg() + speed_north_deg_sec * dt);
 329     pos.setLongitudeDeg(pos.getLongitudeDeg() + speed_east_deg_sec * dt);
 330     pos.setElevationFt(tgt_altitude_ft);
 331     pitch = tgt_pitch;
 332
 333     // adjust heading based on current _rudder angle
 334     if (turn_radius_ft <= 0)
 335         turn_radius_ft = 0; // don't allow nonsense values
 336
 337     if (_rudder > 45)
 338         _rudder = 45;
 339
 340     if (_rudder < -45)
 341         _rudder = -45;
 342
 343
 344     //we assume that at slow speed ships will manoeuvre using engines/bow thruster
 345         if(type == "ship" || type == "carrier" || type == "escort"){
 346
 347                 if (fabs(speed)<=5)
 348                         _sp_turn_radius_ft = _fixed_turn_radius;
 349                 else {
 350                         // adjust turn radius for speed. The equation is very approximate.
 351                         // we need to allow for negative speeds
 352                         _sp_turn_radius_ft = 10 * pow ((fabs(speed) - 15), 2) + turn_radius_ft;
 353                 }
 354
 355         } else {
 356
 357                 if (fabs(speed) <= 40)
 358            _sp_turn_radius_ft = _fixed_turn_radius;
 359                 else {
 360                         // adjust turn radius for speed.
 361                         _sp_turn_radius_ft = turn_radius_ft;
 362                 }
 363         }
 364
 365
 366     if (_rudder <= -0.25 || _rudder >= 0.25) {
 367         // adjust turn radius for _rudder angle. The equation is even more approximate.
 368         float a = 19;
 369         float b = -0.2485;
 370         float c = 0.543;
 371
 372         _rd_turn_radius_ft = (a * exp(b * fabs(_rudder)) + c) * _sp_turn_radius_ft;
 373
 374         // calculate the angle, alpha, subtended by the arc traversed in time dt
 375         alpha = ((speed * 1.686 * dt) / _rd_turn_radius_ft) * SG_RADIANS_TO_DEGREES;
 376         //cout << _name << " alpha " << alpha << endl;
 377         // make sure that alpha is applied in the right direction
 378         hdg += alpha * sign(_rudder);
 379
 380         SG_NORMALIZE_RANGE(hdg, 0.0, 360.0);
 381
 382         //adjust roll for rudder angle and speed. Another bit of voodoo
 383         raw_roll = _roll_factor * speed * _rudder;
 384     } else {
 385         // _rudder angle is 0
 386         raw_roll = 0;
 387     }
 388
 389     //low pass filter
 390     if (speed < 0)
 391         roll = -roll;
 392
 393     roll = (raw_roll * _roll_constant) + (roll * (1 - _roll_constant));
 394
 395     // adjust target _rudder angle if heading lock engaged
 396     double rudder_diff = 0.0;
 397     if (_hdg_lock) {
 398         double rudder_sense = 0.0;
 399         double diff = fabs(hdg - tgt_heading);
 400         //cout << "_rudder diff" << diff << endl;
 401         if (diff > 180)
 402             diff = fabs(diff - 360);
 403
 404         double sum = hdg + diff;
 405
 406         if (sum > 360.0)
 407             sum -= 360.0;
 408
 409         if (fabs(sum - tgt_heading)< 1.0)
 410             rudder_sense = 1.0;
 411         else
 412             rudder_sense = -1.0;
 413
 414         if (speed < 0)
 415             rudder_sense = -rudder_sense;
 416
 417         if (diff < 15)
 418             _tgt_rudder = diff * rudder_sense;
 419         else
 420             _tgt_rudder = 45 * rudder_sense;
 421
 422         rudder_diff = _tgt_rudder - _rudder;
 423     }
 424
 425     // set the _rudder limit by speed
 426     if (type == "ship" || type == "carrier" || type == "escort"){
 427
 428         if (speed <= 40)
 429             rudder_limit = (-0.825 * speed) + 35;
 430         else
 431             rudder_limit = 2;
 432
 433     } else
 434         rudder_limit = 20;
 435
 436     if (fabs(rudder_diff)> 0.1) { // apply dead zone
 437
 438         if (rudder_diff > 0.0) {
 439             _rudder += _rudder_constant * dt;
 440
 441             if (_rudder > rudder_limit) // apply the _rudder limit
 442                 _rudder = rudder_limit;
 443
 444         } else if (rudder_diff < 0.0) {
 445             _rudder -= _rudder_constant * dt;
 446
 447             if (_rudder < -rudder_limit)
 448                 _rudder = -rudder_limit;
 449
 450         }
 451
 452         // do calculations for radar
 453         UpdateRadar(manager);
 454     }
 455 }//end function
 456
 457 void FGAIShip::AccelTo(double speed) {
 458     tgt_speed = speed;
 459 }
 460
 461 void FGAIShip::PitchTo(double angle) {
 462     tgt_pitch = angle;
 463 }
 464
 465 void FGAIShip::RollTo(double angle) {
 466     tgt_roll = angle;
 467 }
 468
 469 void FGAIShip::YawTo(double angle) {
 470 }
 471
 472 void FGAIShip::ClimbTo(double altitude) {
 473     tgt_altitude_ft = altitude;
 474     _setAltitude(altitude);
 475 }
 476
 477 void FGAIShip::TurnTo(double heading) {
 478     tgt_heading = heading - _lead_angle + _tow_angle;
 479     SG_NORMALIZE_RANGE(tgt_heading, 0.0, 360.0);
 480     _hdg_lock = true;
 481 }
 482
 483 double FGAIShip::sign(double x) {
 484     if (x < 0.0)
 485         return -1.0;
 486     else
 487         return 1.0;
 488 }
 489
 490 void FGAIShip::setFlightPlan(FGAIFlightPlan* f) {
 491     fp = f;
 492 }
 493
 494 void FGAIShip::setStartTime(const string& st) {
 495     _start_time = st;
 496 }
 497
 498 void FGAIShip::setUntilTime(const string& ut) {
 499     _until_time = ut;
 500     props->setStringValue("waypoint/wait-until-time", _until_time.c_str());
 501 }
 502
 503 void FGAIShip::setCurrName(const string& c) {
 504     _curr_name = c;
 505     props->setStringValue("waypoint/name-curr", _curr_name.c_str());
 506 }
 507
 508 void FGAIShip::setNextName(const string& n) {
 509     _next_name = n;
 510     props->setStringValue("waypoint/name-next", _next_name.c_str());
 511 }
 512
 513 void FGAIShip::setPrevName(const string& p) {
 514     _prev_name = p;
 515     props->setStringValue("waypoint/name-prev", _prev_name.c_str());
 516 }
 517
 518 void FGAIShip::setRepeat(bool r) {
 519     _repeat = r;
 520 }
 521
 522 void FGAIShip::setRestart(bool r) {
 523     _restart = r;
 524 }
 525
 526 void FGAIShip::setMissed(bool m) {
 527     _missed = m;
 528     props->setBoolValue("waypoint/missed", _missed);
 529 }
 530
 531 void FGAIShip::setRudder(float r) {
 532     _rudder = r;
 533 }
 534
 535 void FGAIShip::setRoll(double rl) {
 536     roll = rl;
 537 }
 538
 539 void FGAIShip::setLeadAngleGain(double g) {
 540     _lead_angle_gain = g;
 541 }
 542
 543 void FGAIShip::setLeadAngleLimit(double l) {
 544     _lead_angle_limit = l;
 545 }
 546
 547 void FGAIShip::setLeadAngleProp(double p) {
 548     _proportion = p;
 549 }
 550
 551 void FGAIShip::setRudderConstant(double rc) {
 552     _rudder_constant = rc;
 553 }
 554
 555 void FGAIShip::setSpeedConstant(double sc) {
 556     _speed_constant = sc;
 557 }
 558
 559 void FGAIShip::setFixedTurnRadius(double ftr) {
 560     _fixed_turn_radius = ftr;
 561 }
 562
 563 void FGAIShip::setInitialTunnel(bool t) {
 564     _initial_tunnel = t;
 565     setTunnel(_initial_tunnel);
 566 }
 567
 568 void FGAIShip::setTunnel(bool t) {
 569     _tunnel = t;
 570 }
 571
 572 void FGAIShip::setWPNames() {
 573
 574     if (prev != 0)
 575         setPrevName(prev->getName());
 576     else
 577         setPrevName("");
 578
 579     if (curr != 0)
 580         setCurrName(curr->getName());
 581     else{
 582         setCurrName("");
 583         SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: current wp name error" );
 584     }
 585
 586     if (next != 0)
 587         setNextName(next->getName());
 588     else
 589         setNextName("");
 590
 591     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: prev wp name " << prev->getName());
 592     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: current wp name " << curr->getName());
 593     SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: next wp name " << next->getName());
 594
 595 }
 596
 597 double FGAIShip::getRange(double lat, double lon, double lat2, double lon2) const {
 598
 599     double course, distance, az2;
 600
 601     //calculate the bearing and range of the second pos from the first
 602     geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &az2, &distance);
 603     distance *= SG_METER_TO_NM;
 604     return distance;
 605 }
 606
 607 double FGAIShip::getCourse(double lat, double lon, double lat2, double lon2) const {
 608
 609     double course, distance, recip;
 610
 611     //calculate the bearing and range of the second pos from the first
 612     geo_inverse_wgs_84(lat, lon, lat2, lon2, &course, &recip, &distance);
 613     if (tgt_speed >= 0) {
 614         return course;
 615         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: course " << course);
 616     } else {
 617         return recip;
 618         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: recip " << recip);
 619     }
 620 }
 621
 622 void FGAIShip::ProcessFlightPlan(double dt) {
 623
 624     if ( dt < 0.00001 ) {
 625         return;
 626     }
 627
 628     double time_sec = getDaySeconds();
 629
 630     _dt_count += dt;
 631
 632     ///////////////////////////////////////////////////////////////////////////
 633     // Check Execution time (currently once every 1 sec)
 634     // Add a bit of randomization to prevent the execution of all flight plans
 635     // in synchrony, which can add significant periodic framerate flutter.
 636     ///////////////////////////////////////////////////////////////////////////
 637
 638     //cout << "_start_sec " << _start_sec << " time_sec " << time_sec << endl;
 639     if (_dt_count < _next_run && _start_sec < time_sec)
 640         return;
 641
 642     _next_run = 0.05 + (0.025 * sg_random());
 643
 644     double until_time_sec = 0;
 645     _missed = false;
 646
 647     // check to see if we've reached the point for our next turn
 648     // if the range to the waypoint is less than the calculated turn
 649     // radius we can start the turn to the next leg
 650     _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->getLatitude(), curr->getLongitude());
 651     _range_rate = (_wp_range - _old_range) / _dt_count;
 652     double sp_turn_radius_nm = _sp_turn_radius_ft / 6076.1155;
 653     // we need to try to identify a _missed waypoint
 654
 655     // calculate the time needed to turn through an arc of 90 degrees,
 656     // and allow a time error
 657     if (speed != 0)
 658         _missed_time_sec = 10 + ((SGD_PI * sp_turn_radius_nm * 60 * 60) / (2 * fabs(speed)));
 659     else
 660         _missed_time_sec = 10;
 661
 662     _missed_range = 4 * sp_turn_radius_nm;
 663
 664     //cout << _name << " range_rate " << _range_rate << " " << _new_waypoint<< endl ;
 665     //if ((_range_rate > 0) && !_new_waypoint){
 666     if (_range_rate > 0 && _wp_range < _missed_range && !_new_waypoint){
 667         _missed_count += _dt_count;
 668     }
 669
 670     if (_missed_count >= 120)
 671         setMissed(true);
 672     else if (_missed_count >= _missed_time_sec)
 673         setMissed(true);
 674     else
 675         setMissed(false);
 676
 677     _old_range = _wp_range;
 678     setWPNames();
 679
 680     if ((_wp_range < (sp_turn_radius_nm * 1.25)) || _missed || (_waiting && !_new_waypoint)) {
 681
 682         if (_next_name == "TUNNEL"){
 683             _tunnel = !_tunnel;
 684
 685             SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " " << sp_turn_radius_nm );
 686
 687             fp->IncrementWaypoint(false);
 688             next = fp->getNextWaypoint();
 689
 690             if (next->getName() == "WAITUNTIL" || next->getName() == "WAIT"
 691                 || next->getName() == "END" || next->getName() == "TUNNEL")
 692                 return;
 693
 694             prev = curr;
 695             fp->IncrementWaypoint(false);
 696             curr = fp->getCurrentWaypoint();
 697             next = fp->getNextWaypoint();
 698
 699         }else if(_next_name == "END" || fp->getNextWaypoint() == 0) {
 700
 701             if (_repeat) {
 702                 SG_LOG(SG_GENERAL, SG_INFO, "AIShip: "<< _name << " Flightplan repeating ");
 703                 fp->restart();
 704                 prev = curr;
 705                 curr = fp->getCurrentWaypoint();
 706                 next = fp->getNextWaypoint();
 707                 setWPNames();
 708                 _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->getLatitude(), curr->getLongitude());
 709                 _old_range = _wp_range;
 710                 _range_rate = 0;
 711                 _new_waypoint = true;
 712                 _missed_count = 0;
 713                 _lead_angle = 0;
 714                 AccelTo(prev->getSpeed());
 715             } else if (_restart){
 716                 SG_LOG(SG_GENERAL, SG_INFO, "AIShip: " << _name << " Flightplan restarting ");
 717                 _missed_count = 0;
 718                 initFlightPlan();
 719             } else {
 720                 SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " Flightplan dying ");
 721                 setDie(true);
 722                 _dt_count = 0;
 723                 return;
 724             }
 725
 726         } else if (_next_name == "WAIT") {
 727
 728             if (_wait_count < next->getTime_sec()) {
 729                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " waiting ");
 730                 setSpeed(0);
 731                 _waiting = true;
 732                 _wait_count += _dt_count;
 733                 _dt_count = 0;
 734                 _lead_angle = 0;
 735                 return;
 736             } else {
 737                 SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name
 738                     << " wait done: getting new waypoints ");
 739                 _waiting = false;
 740                 _wait_count = 0;
 741                 fp->IncrementWaypoint(false);
 742                 next = fp->getNextWaypoint();
 743
 744                 if (next->getName() == "WAITUNTIL" || next->getName() == "WAIT"
 745                     || next->getName() == "END" || next->getName() == "TUNNEL")
 746                     return;
 747
 748                 prev = curr;
 749                 fp->IncrementWaypoint(false);
 750                 curr = fp->getCurrentWaypoint();
 751                 next = fp->getNextWaypoint();
 752             }
 753
 754         } else if (_next_name == "WAITUNTIL") {
 755             time_sec = getDaySeconds();
 756             until_time_sec = processTimeString(next->getTime());
 757             _until_time = next->getTime();
 758             setUntilTime(next->getTime());
 759             if (until_time_sec > time_sec) {
 760                 SG_LOG(SG_GENERAL, SG_INFO, "AIShip: " << _name << " "
 761                     << curr->getName() << " waiting until: "
 762                     << _until_time << " " << until_time_sec << " now " << time_sec );
 763                 setSpeed(0);
 764                 _lead_angle = 0;
 765                 _waiting = true;
 766                 return;
 767             } else {
 768                 SG_LOG(SG_GENERAL, SG_INFO, "AIShip: "
 769                     << _name << " wait until done: getting new waypoints ");
 770                 setUntilTime("");
 771                 fp->IncrementWaypoint(false);
 772
 773                 while (next->getName() == "WAITUNTIL") {
 774                     fp->IncrementWaypoint(false);
 775                     next = fp->getNextWaypoint();
 776                 }
 777
 778                 if (next->getName() == "WAIT")
 779                     return;
 780
 781                 prev = curr;
 782                 fp->IncrementWaypoint(false);
 783                 curr = fp->getCurrentWaypoint();
 784                 next = fp->getNextWaypoint();
 785                 _waiting = false;
 786             }
 787
 788         } else {
 789             //now reorganise the waypoints, so that next becomes current and so on
 790             SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " getting new waypoints ");
 791             fp->IncrementWaypoint(false);
 792             prev = fp->getPreviousWaypoint(); //first waypoint
 793             curr = fp->getCurrentWaypoint();  //second waypoint
 794             next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 795         }
 796
 797         setWPNames();
 798         _new_waypoint = true;
 799         _missed_count = 0;
 800         _range_rate = 0;
 801         _lead_angle = 0;
 802         _wp_range = getRange(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->getLatitude(), curr->getLongitude());
 803         _old_range = _wp_range;
 804         setWPPos();
 805         object_type type = getType();
 806
 807         if (type != 10)
 808             AccelTo(prev->getSpeed());
 809
 810         _curr_alt = curr->getAltitude();
 811         _prev_alt = prev->getAltitude();
 812
 813     } else {
 814         _new_waypoint = false;
 815     }
 816
 817     //   now revise the required course for the next way point
 818     _course = getCourse(pos.getLatitudeDeg(), pos.getLongitudeDeg(), curr->getLatitude(), curr->getLongitude());
 819
 820     if (finite(_course))
 821         TurnTo(_course);
 822     else
 823         SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: Bearing or Range is not a finite number");
 824
 825     _dt_count = 0;
 826 } // end Processing FlightPlan
 827
 828 bool FGAIShip::initFlightPlan() {
 829
 830     SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " initializing waypoints ");
 831
 832     bool init = false;
 833     _start_sec = 0;
 834     _tunnel = _initial_tunnel;
 835
 836     fp->restart();
 837     fp->IncrementWaypoint(false);
 838
 839     prev = fp->getPreviousWaypoint(); //first waypoint
 840     curr = fp->getCurrentWaypoint();  //second waypoint
 841     next = fp->getNextWaypoint();     //third waypoint (might not exist!)
 842
 843     while (curr->getName() == "WAIT" || curr->getName() == "WAITUNTIL") {  // don't wait when initialising
 844         SG_LOG(SG_GENERAL, SG_DEBUG, "AIShip: " << _name << " re-initializing waypoints ");
 845         fp->IncrementWaypoint(false);
 846         curr = fp->getCurrentWaypoint();
 847         next = fp->getNextWaypoint();
 848     } // end while loop
 849
 850     if (!_start_time.empty()){
 851         _start_sec = processTimeString(_start_time);
 852         double day_sec = getDaySeconds();
 853
 854         if (_start_sec < day_sec){
 855             //cout << "flight plan has already started " << _start_time << endl;
 856             init = advanceFlightPlan(_start_sec, day_sec);
 857
 858         } else if (_start_sec > day_sec && _repeat) {
 859             //cout << "flight plan has not started, " << _start_time;
 860             //cout << "offsetting start time by -24 hrs" << endl;
 861             _start_sec -= _day;
 862             init = advanceFlightPlan(_start_sec, day_sec);
 863         }
 864
 865         if (init)
 866             _start_sec = 0; // set to zero for an immediate start of the Flight Plan
 867         else {
 868             fp->restart();
 869             fp->IncrementWaypoint(false);
 870             prev = fp->getPreviousWaypoint();
 871             curr = fp->getCurrentWaypoint();
 872             next = fp->getNextWaypoint();
 873             return false;
 874         }
 875
 876     } else {
 877         setLatitude(prev->getLatitude());
 878         setLongitude(prev->getLongitude());
 879         setSpeed(prev->getSpeed());
 880     }
 881
 882     setWPNames();
 883     setHeading(getCourse(prev->getLatitude(), prev->getLongitude(), curr->getLatitude(), curr->getLongitude()));
 884     _wp_range = getRange(prev->getLatitude(), prev->getLongitude(), curr->getLatitude(), curr->getLongitude());
 885     _old_range = _wp_range;
 886     _range_rate = 0;
 887     _hdg_lock = true;
 888     _missed = false;
 889     _missed_count = 0;
 890     _new_waypoint = true;
 891
 892     SG_LOG(SG_GENERAL, SG_ALERT, "AIShip: " << _name << " done initialising waypoints " << _tunnel);
 893     if (prev)
 894         init = true;
 895
 896     if (init)
 897         return true;
 898     else
 899         return false;
 900
 901 } // end of initialization
 902
 903
 904 double FGAIShip::processTimeString(const string& theTime) {
 905
 906     int Hour;
 907     int Minute;
 908     int Second;
 909
 910     // first split theTime string into
 911     //  hour, minute, second and convert to int;
 912     Hour   = atoi(theTime.substr(0,2).c_str());
 913     Minute = atoi(theTime.substr(3,5).c_str());
 914     Second = atoi(theTime.substr(6,8).c_str());
 915
 916     // offset by a day-sec to allow for starting a day earlier
 917     double time_seconds = Hour * 3600
 918         + Minute * 60
 919         + Second;
 920
 921     return time_seconds;
 922 }
 923
 924 double FGAIShip::getDaySeconds () {
 925     // Date and time
 926     struct tm *t = globals->get_time_params()->getGmt();
 927
 928     double day_seconds = t->tm_hour * 3600
 929         + t->tm_min * 60
 930         + t->tm_sec;
 931
 932     return day_seconds;
 933 }
 934
 935 bool FGAIShip::advanceFlightPlan (double start_sec, double day_sec) {
 936
 937     double elapsed_sec = start_sec;
 938     double distance_nm = 0;
 939
 940     //cout << "advancing flight plan start_sec: " << start_sec << " " << day_sec << endl;
 941
 942     while ( elapsed_sec < day_sec ) {
 943
 944         if (next->getName() == "END" || fp->getNextWaypoint() == 0) {
 945
 946             if (_repeat ) {
 947                 //cout << _name << ": " << "restarting flightplan" << endl;
 948                 fp->restart();
 949                 curr = fp->getCurrentWaypoint();
 950                 next = fp->getNextWaypoint();
 951             } else {
 952                 //cout << _name << ": " << "ending flightplan" << endl;
 953                 setDie(true);
 954                 return false;
 955             }
 956
 957         } else if (next->getName() == "WAIT") {
 958             //cout << _name << ": begin WAIT: " << prev->name << " ";
 959             //cout << curr->name << " " << next->name << endl;
 960
 961             elapsed_sec += next->getTime_sec();
 962
 963             if ( elapsed_sec >= day_sec)
 964                 continue;
 965
 966             fp->IncrementWaypoint(false);
 967             next = fp->getNextWaypoint();
 968
 969             if (next->getName() != "WAITUNTIL" && next->getName() != "WAIT"
 970                 && next->getName() != "END") {
 971                     prev = curr;
 972                     fp->IncrementWaypoint(false);
 973                     curr = fp->getCurrentWaypoint();
 974                     next = fp->getNextWaypoint();
 975             }
 976
 977         } else if (next->getName() == "WAITUNTIL") {
 978             double until_sec = processTimeString(next->getTime());
 979
 980             if (until_sec > _start_sec && start_sec < 0)
 981                 until_sec -= _day;
 982
 983             if (elapsed_sec < until_sec)
 984                 elapsed_sec = until_sec;
 985
 986             if (elapsed_sec >= day_sec )
 987                 break;
 988
 989             fp->IncrementWaypoint(false);
 990             next = fp->getNextWaypoint();
 991
 992             if (next->getName() != "WAITUNTIL" && next->getName() != "WAIT") {
 993                 prev = curr;
 994                 fp->IncrementWaypoint(false);
 995                 curr = fp->getCurrentWaypoint();
 996                 next = fp->getNextWaypoint();
 997             }
 998
 999             //cout << _name << ": end WAITUNTIL: ";
1000             //cout << prev->name << " " << curr->name << " " << next->name <<  endl;
1001
1002         } else {
1003             distance_nm = getRange(prev->getLatitude(), prev->getLongitude(), curr->getLatitude(), curr->getLongitude());
1004             elapsed_sec += distance_nm * 60 * 60 / prev->getSpeed();
1005
1006             if (elapsed_sec >= day_sec)
1007                 continue;
1008
1009             fp->IncrementWaypoint(false);
1010             prev = fp->getPreviousWaypoint();
1011             curr = fp->getCurrentWaypoint();
1012             next = fp->getNextWaypoint();
1013         }
1014
1015     }   // end while
1016
1017     // the required position lies between the previous and current waypoints
1018     // so we will calculate the distance back up the track from the current waypoint
1019     // then calculate the lat and lon.
1020
1021     //cout << "advancing flight plan done elapsed_sec: " << elapsed_sec
1022     //    << " " << day_sec << endl;
1023
1024     double time_diff = elapsed_sec - day_sec;
1025     double lat, lon, recip;
1026
1027     //cout << " time diff " << time_diff << endl;
1028
1029     if (next->getName() == "WAIT" ){
1030         setSpeed(0);
1031         lat = curr->getLatitude();
1032         lon = curr->getLongitude();
1033         _wait_count= time_diff;
1034         _waiting = true;
1035     } else if (next->getName() == "WAITUNTIL") {
1036         setSpeed(0);
1037         lat = curr->getLatitude();
1038         lon = curr->getLongitude();
1039         _waiting = true;
1040     } else {
1041         setSpeed(prev->getSpeed());
1042         distance_nm = speed * time_diff / (60 * 60);
1043         double brg = getCourse(curr->getLatitude(), curr->getLongitude(), prev->getLatitude(), prev->getLongitude());
1044
1045         //cout << " brg " << brg << " from " << curr->name << " to " << prev->name << " "
1046         //    << " lat "  << curr->latitude << " lon " << curr->longitude
1047         //    << " distance m " << distance_nm * SG_NM_TO_METER << endl;
1048
1049         lat = geo_direct_wgs_84 (curr->getLatitude(), curr->getLongitude(), brg,
1050             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1051         lon = geo_direct_wgs_84 (curr->getLatitude(), curr->getLongitude(), brg,
1052             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1053         recip = geo_direct_wgs_84 (curr->getLatitude(), curr->getLongitude(), brg,
1054             distance_nm * SG_NM_TO_METER, &lat, &lon, &recip );
1055     }
1056
1057     setLatitude(lat);
1058     setLongitude(lon);
1059
1060     return true;
1061 }
1062
1063 void FGAIShip::setWPPos() {
1064
1065     if (curr->getName() == "END" || curr->getName() == "WAIT"
1066         || curr->getName() == "WAITUNTIL" || curr->getName() == "TUNNEL"){
1067             //cout << curr->name << " returning" << endl;
1068             return;
1069     }
1070
1071     double elevation_m = 0;
1072     wppos.setLatitudeDeg(curr->getLatitude());
1073     wppos.setLongitudeDeg(curr->getLongitude());
1074     wppos.setElevationM(0);
1075
1076     if (curr->getOn_ground()){
1077
1078         if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(wppos, 3000),
1079             elevation_m, &_material, 0)){
1080                 wppos.setElevationM(elevation_m);
1081         }
1082
1083         //cout << curr->name << " setting measured  elev " << elevation_m << endl;
1084
1085     } else {
1086         wppos.setElevationM(curr->getAltitude());
1087         //cout << curr->name << " setting FP elev " << elevation_m << endl;
1088     }
1089
1090     curr->setAltitude(wppos.getElevationM());
1091
1092 }
1093
1094 void FGAIShip::setXTrackError() {
1095
1096     double course = getCourse(prev->getLatitude(), prev->getLongitude(),
1097         curr->getLatitude(), curr->getLongitude());
1098     double brg = getCourse(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
1099         curr->getLatitude(), curr->getLongitude());
1100     double xtrack_error_nm = sin((course - brg)* SG_DEGREES_TO_RADIANS) * _wp_range;
1101     double factor = -0.0045 * speed + 1;
1102     double limit = _lead_angle_limit * factor;
1103
1104     if (_wp_range > 0){
1105         _lead_angle = atan2(xtrack_error_nm,(_wp_range * _proportion)) * SG_RADIANS_TO_DEGREES;
1106     } else
1107         _lead_angle = 0;
1108
1109     _lead_angle *= _lead_angle_gain * factor;
1110     _xtrack_error = xtrack_error_nm * 6076.1155;
1111
1112     SG_CLAMP_RANGE(_lead_angle, -limit, limit);
1113
1114 }