src/AIModel/AICarrier.cxx

   1 // FGAICarrier - FGAIShip-derived class creates an AI aircraft carrier
   2 //
   3 // Written by David Culp, started October 2004.
   4 // - davidculp2@comcast.net
   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 #include <algorithm>
  25 #include <string>
  26 #include <vector>
  27
  28 #include <osg/Geode>
  29 #include <osg/Drawable>
  30 #include <osg/Transform>
  31 #include <osg/NodeVisitor>
  32 #include <osg/TemplatePrimitiveFunctor>
  33
  34 #include <simgear/sg_inlines.h>
  35 #include <simgear/math/SGMath.hxx>
  36 #include <simgear/math/sg_geodesy.hxx>
  37 #include <simgear/scene/util/SGSceneUserData.hxx>
  38 #include <simgear/scene/bvh/BVHGroup.hxx>
  39 #include <simgear/scene/bvh/BVHLineGeometry.hxx>
  40
  41 #include <math.h>
  42 #include <Main/util.hxx>
  43 #include <Main/viewer.hxx>
  44
  45 #include "AICarrier.hxx"
  46
  47 /// Hmm: move that kind of configuration into the model file???
  48 class LineCollector : public osg::NodeVisitor {
  49     struct LinePrimitiveFunctor {
  50         LinePrimitiveFunctor() : _lineCollector(0)
  51         { }
  52         void operator() (const osg::Vec3&, bool)
  53         { }
  54         void operator() (const osg::Vec3& v1, const osg::Vec3& v2, bool)
  55         { if (_lineCollector) _lineCollector->addLine(v1, v2); }
  56         void operator() (const osg::Vec3&, const osg::Vec3&, const osg::Vec3&,
  57                          bool)
  58         { }
  59         void operator() (const osg::Vec3&, const osg::Vec3&, const osg::Vec3&,
  60                          const osg::Vec3&, bool)
  61         { }
  62         LineCollector* _lineCollector;
  63     };
  64
  65 public:
  66     LineCollector() :
  67         osg::NodeVisitor(osg::NodeVisitor::NODE_VISITOR,
  68                          osg::NodeVisitor::TRAVERSE_ALL_CHILDREN)
  69     { }
  70     virtual void apply(osg::Geode& geode)
  71     {
  72         osg::TemplatePrimitiveFunctor<LinePrimitiveFunctor> pf;
  73         pf._lineCollector = this;
  74         for (unsigned i = 0; i < geode.getNumDrawables(); ++i) {
  75             geode.getDrawable(i)->accept(pf);
  76         }
  77     }
  78     virtual void apply(osg::Node& node)
  79     {
  80         traverse(node);
  81     }
  82     virtual void apply(osg::Transform& transform)
  83     {
  84         osg::Matrix matrix = _matrix;
  85         if (transform.computeLocalToWorldMatrix(_matrix, this))
  86             traverse(transform);
  87         _matrix = matrix;
  88     }
  89
  90     const std::vector<SGLineSegmentf>& getLineSegments() const
  91     { return _lineSegments; }
  92
  93     void addLine(const osg::Vec3& v1, const osg::Vec3& v2)
  94     {
  95         // Trick to get the ends in the right order.
  96         // Use the x axis in the original coordinate system. Choose the
  97         // most negative x-axis as the one pointing forward
  98         SGVec3f tv1(_matrix.preMult(v1));
  99         SGVec3f tv2(_matrix.preMult(v2));
 100         if (tv1[0] > tv2[0])
 101             _lineSegments.push_back(SGLineSegmentf(tv1, tv2));
 102         else
 103             _lineSegments.push_back(SGLineSegmentf(tv2, tv1));
 104     }
 105
 106     void addBVHElements(osg::Node& node, simgear::BVHLineGeometry::Type type)
 107     {
 108         if (_lineSegments.empty())
 109             return;
 110
 111         SGSceneUserData* userData;
 112         userData = SGSceneUserData::getOrCreateSceneUserData(&node);
 113
 114         simgear::BVHNode* bvNode = userData->getBVHNode();
 115         if (!bvNode && _lineSegments.size() == 1) {
 116             simgear::BVHLineGeometry* bvLine;
 117             bvLine = new simgear::BVHLineGeometry(_lineSegments.front(), type);
 118             userData->setBVHNode(bvLine);
 119             return;
 120         }
 121
 122         simgear::BVHGroup* group = new simgear::BVHGroup;
 123         if (bvNode)
 124             group->addChild(bvNode);
 125
 126         for (unsigned i = 0; i < _lineSegments.size(); ++i) {
 127             simgear::BVHLineGeometry* bvLine;
 128             bvLine = new simgear::BVHLineGeometry(_lineSegments[i], type);
 129             group->addChild(bvLine);
 130         }
 131         userData->setBVHNode(group);
 132     }
 133
 134 private:
 135     osg::Matrix _matrix;
 136     std::vector<SGLineSegmentf> _lineSegments;
 137 };
 138
 139 class FGCarrierVisitor : public osg::NodeVisitor {
 140 public:
 141     FGCarrierVisitor(FGAICarrier* carrier,
 142                      const std::list<std::string>& wireObjects,
 143                      const std::list<std::string>& catapultObjects) :
 144         osg::NodeVisitor(osg::NodeVisitor::NODE_VISITOR,
 145                          osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
 146         mWireObjects(wireObjects),
 147         mCatapultObjects(catapultObjects)
 148     { }
 149     virtual void apply(osg::Node& node)
 150     {
 151         if (std::find(mWireObjects.begin(), mWireObjects.end(), node.getName())
 152             != mWireObjects.end()) {
 153             LineCollector lineCollector;
 154             node.accept(lineCollector);
 155             simgear::BVHLineGeometry::Type type;
 156             type = simgear::BVHLineGeometry::CarrierWire;
 157             lineCollector.addBVHElements(node, type);
 158         }
 159         if (std::find(mCatapultObjects.begin(), mCatapultObjects.end(),
 160                       node.getName()) != mCatapultObjects.end()) {
 161             LineCollector lineCollector;
 162             node.accept(lineCollector);
 163             simgear::BVHLineGeometry::Type type;
 164             type = simgear::BVHLineGeometry::CarrierCatapult;
 165             lineCollector.addBVHElements(node, type);
 166         }
 167
 168         traverse(node);
 169     }
 170
 171 private:
 172     std::list<std::string> mWireObjects;
 173     std::list<std::string> mCatapultObjects;
 174 };
 175
 176 FGAICarrier::FGAICarrier() : FGAIShip(otCarrier) {
 177 }
 178
 179 FGAICarrier::~FGAICarrier() {
 180 }
 181
 182 void FGAICarrier::readFromScenario(SGPropertyNode* scFileNode) {
 183   if (!scFileNode)
 184     return;
 185
 186   FGAIShip::readFromScenario(scFileNode);
 187
 188   setRadius(scFileNode->getDoubleValue("turn-radius-ft", 2000));
 189   setSign(scFileNode->getStringValue("pennant-number"));
 190   setWind_from_east(scFileNode->getDoubleValue("wind_from_east", 0));
 191   setWind_from_north(scFileNode->getDoubleValue("wind_from_north", 0));
 192   setTACANChannelID(scFileNode->getStringValue("TACAN-channel-ID", "029Y"));
 193   setMaxLat(scFileNode->getDoubleValue("max-lat", 0));
 194   setMinLat(scFileNode->getDoubleValue("min-lat", 0));
 195   setMaxLong(scFileNode->getDoubleValue("max-long", 0));
 196   setMinLong(scFileNode->getDoubleValue("min-long", 0));
 197   setMPControl(scFileNode->getBoolValue("mp-control", false));
 198
 199   SGPropertyNode* flols = scFileNode->getChild("flols-pos");
 200   if (flols) {
 201     // Transform to the right coordinate frame, configuration is done in
 202     // the usual x-back, y-right, z-up coordinates, computations
 203     // in the simulation usual body x-forward, y-right, z-down coordinates
 204     flols_off(0) = - flols->getDoubleValue("x-offset-m", 0);
 205     flols_off(1) = flols->getDoubleValue("y-offset-m", 0);
 206     flols_off(2) = - flols->getDoubleValue("z-offset-m", 0);
 207   } else
 208     flols_off = SGVec3d::zeros();
 209
 210   std::vector<SGPropertyNode_ptr> props = scFileNode->getChildren("wire");
 211   std::vector<SGPropertyNode_ptr>::const_iterator it;
 212   for (it = props.begin(); it != props.end(); ++it) {
 213     std::string s = (*it)->getStringValue();
 214     if (!s.empty())
 215       wire_objects.push_back(s);
 216   }
 217
 218   props = scFileNode->getChildren("catapult");
 219   for (it = props.begin(); it != props.end(); ++it) {
 220     std::string s = (*it)->getStringValue();
 221     if (!s.empty())
 222       catapult_objects.push_back(s);
 223   }
 224
 225   props = scFileNode->getChildren("parking-pos");
 226   for (it = props.begin(); it != props.end(); ++it) {
 227     string name = (*it)->getStringValue("name", "unnamed");
 228     // Transform to the right coordinate frame, configuration is done in
 229     // the usual x-back, y-right, z-up coordinates, computations
 230     // in the simulation usual body x-forward, y-right, z-down coordinates
 231     double offset_x = -(*it)->getDoubleValue("x-offset-m", 0);
 232     double offset_y = (*it)->getDoubleValue("y-offset-m", 0);
 233     double offset_z = -(*it)->getDoubleValue("z-offset-m", 0);
 234     double hd = (*it)->getDoubleValue("heading-offset-deg", 0);
 235     ParkPosition pp(name, SGVec3d(offset_x, offset_y, offset_z), hd);
 236     ppositions.push_back(pp);
 237   }
 238 }
 239
 240 void FGAICarrier::setWind_from_east(double fps) {
 241     wind_from_east = fps;
 242 }
 243
 244 void FGAICarrier::setWind_from_north(double fps) {
 245     wind_from_north = fps;
 246 }
 247
 248 void FGAICarrier::setMaxLat(double deg) {
 249     max_lat = fabs(deg);
 250 }
 251
 252 void FGAICarrier::setMinLat(double deg) {
 253     min_lat = fabs(deg);
 254 }
 255
 256 void FGAICarrier::setMaxLong(double deg) {
 257     max_long = fabs(deg);
 258 }
 259
 260 void FGAICarrier::setMinLong(double deg) {
 261     min_long = fabs(deg);
 262 }
 263
 264 void FGAICarrier::setSign(const string& s) {
 265     sign = s;
 266 }
 267
 268 void FGAICarrier::setTACANChannelID(const string& id) {
 269     TACAN_channel_id = id;
 270 }
 271
 272 void FGAICarrier::setMPControl(bool c) {
 273     MPControl = c;
 274 }
 275
 276 void FGAICarrier::update(double dt) {
 277     // Now update the position and heading. This will compute new hdg and
 278     // roll values required for the rotation speed computation.
 279     FGAIShip::update(dt);
 280
 281     //automatic turn into wind with a target wind of 25 kts otd
 282     //SG_LOG(SG_GENERAL, SG_ALERT, "AICarrier: MPControl " << MPControl );
 283     if (!MPControl){
 284
 285         if(turn_to_launch_hdg){
 286             TurnToLaunch();
 287         } else if(turn_to_recovery_hdg ){
 288             TurnToRecover();
 289         } else if(OutsideBox() || returning ) {// check that the carrier is inside
 290             ReturnToBox();                     // the operating box,
 291         } else {
 292             TurnToBase();
 293         }
 294
 295     } else {
 296         FGAIShip::TurnTo(tgt_heading);
 297         FGAIShip::AccelTo(tgt_speed);
 298     }
 299
 300     UpdateWind(dt);
 301     UpdateElevator(dt, transition_time);
 302     UpdateJBD(dt, jbd_transition_time);
 303
 304     // Transform that one to the horizontal local coordinate system.
 305     SGQuatd ec2hl = SGQuatd::fromLonLat(pos);
 306     // The orientation of the carrier wrt the horizontal local frame
 307     SGQuatd hl2body = SGQuatd::fromYawPitchRollDeg(hdg, pitch, roll);
 308     // and postrotate the orientation of the AIModel wrt the horizontal
 309     // local frame
 310     SGQuatd ec2body = ec2hl*hl2body;
 311     // The cartesian position of the carrier in the wgs84 world
 312     SGVec3d cartPos = SGVec3d::fromGeod(pos);
 313
 314     // The position of the eyepoint - at least near that ...
 315     SGVec3d eyePos(globals->get_current_view()->get_view_pos());
 316     // Add the position offset of the AIModel to gain the earth
 317     // centered position
 318     SGVec3d eyeWrtCarrier = eyePos - cartPos;
 319     // rotate the eyepoint wrt carrier vector into the carriers frame
 320     eyeWrtCarrier = ec2body.transform(eyeWrtCarrier);
 321     // the eyepoints vector wrt the flols position
 322     SGVec3d eyeWrtFlols = eyeWrtCarrier - flols_off;
 323
 324     // the distance from the eyepoint to the flols
 325     dist = norm(eyeWrtFlols);
 326
 327     // now the angle, positive angles are upwards
 328     if (fabs(dist) < SGLimits<float>::min()) {
 329       angle = 0;
 330     } else {
 331       double sAngle = -eyeWrtFlols(2)/dist;
 332       sAngle = SGMiscd::min(1, SGMiscd::max(-1, sAngle));
 333       angle = SGMiscd::rad2deg(asin(sAngle));
 334     }
 335
 336     // set the value of source
 337     if ( angle <= 4.35 && angle > 4.01 )
 338       source = 1;
 339     else if ( angle <= 4.01 && angle > 3.670 )
 340       source = 2;
 341     else if ( angle <= 3.670 && angle > 3.330 )
 342       source = 3;
 343     else if ( angle <= 3.330 && angle > 2.990 )
 344       source = 4;
 345     else if ( angle <= 2.990 && angle > 2.650 )
 346       source = 5;
 347     else if ( angle <= 2.650 )
 348       source = 6;
 349     else
 350       source = 0;
 351 } //end update
 352
 353 bool FGAICarrier::init(bool search_in_AI_path) {
 354     if (!FGAIShip::init(search_in_AI_path))
 355         return false;
 356
 357     _longitude_node = fgGetNode("/position/longitude-deg", true);
 358     _latitude_node = fgGetNode("/position/latitude-deg", true);
 359     _altitude_node = fgGetNode("/position/altitude-ft", true);
 360
 361     _launchbar_state_node = fgGetNode("/gear/launchbar/state", true);
 362
 363     _surface_wind_from_deg_node =
 364             fgGetNode("/environment/config/boundary/entry[0]/wind-from-heading-deg", true);
 365     _surface_wind_speed_node =
 366             fgGetNode("/environment/config/boundary/entry[0]/wind-speed-kt", true);
 367
 368
 369     turn_to_launch_hdg = false;
 370     turn_to_recovery_hdg = false;
 371     turn_to_base_course = true;
 372     returning = false;
 373     in_to_wind = false;
 374
 375     mOpBoxPos = pos;
 376     base_course = hdg;
 377     base_speed = speed;
 378
 379     pos_norm = raw_pos_norm = 0;
 380     elevators = false;
 381     transition_time = 150;
 382     time_constant = 0.005;
 383     jbd_pos_norm = raw_jbd_pos_norm = 0;
 384     jbd = false ;
 385     jbd_transition_time = 3;
 386     jbd_time_constant = 0.1;
 387     return true;
 388 }
 389
 390 void FGAICarrier::initModel(osg::Node *node)
 391 {
 392     // SG_LOG(SG_GENERAL, SG_BULK, "AICarrier::initModel()" );
 393     FGAIShip::initModel(node);
 394     // process the 3d model here
 395     // mark some objects solid, mark the wires ...
 396     FGCarrierVisitor carrierVisitor(this, wire_objects, catapult_objects);
 397     node->accept(carrierVisitor);
 398 }
 399
 400 void FGAICarrier::bind() {
 401     FGAIShip::bind();
 402
 403     props->untie("velocities/true-airspeed-kt");
 404
 405     props->tie("controls/flols/source-lights",
 406                 SGRawValuePointer<int>(&source));
 407     props->tie("controls/flols/distance-m",
 408                 SGRawValuePointer<double>(&dist));
 409     props->tie("controls/flols/angle-degs",
 410                 SGRawValuePointer<double>(&angle));
 411     props->tie("controls/turn-to-launch-hdg",
 412                 SGRawValuePointer<bool>(&turn_to_launch_hdg));
 413     props->tie("controls/in-to-wind",
 414                 SGRawValuePointer<bool>(&turn_to_launch_hdg));
 415     props->tie("controls/base-course-deg",
 416                 SGRawValuePointer<double>(&base_course));
 417     props->tie("controls/base-speed-kts",
 418                 SGRawValuePointer<double>(&base_speed));
 419     props->tie("controls/start-pos-lat-deg",
 420                SGRawValueMethods<SGGeod,double>(pos, &SGGeod::getLatitudeDeg));
 421     props->tie("controls/start-pos-long-deg",
 422                SGRawValueMethods<SGGeod,double>(pos, &SGGeod::getLongitudeDeg));
 423     props->tie("controls/mp-control",
 424         SGRawValuePointer<bool>(&MPControl));
 425     props->tie("velocities/speed-kts",
 426                 SGRawValuePointer<double>(&speed));
 427     props->tie("environment/surface-wind-speed-true-kts",
 428                 SGRawValuePointer<double>(&wind_speed_kts));
 429     props->tie("environment/surface-wind-from-true-degs",
 430                 SGRawValuePointer<double>(&wind_from_deg));
 431     props->tie("environment/rel-wind-from-degs",
 432                 SGRawValuePointer<double>(&rel_wind_from_deg));
 433     props->tie("environment/rel-wind-from-carrier-hdg-degs",
 434                 SGRawValuePointer<double>(&rel_wind));
 435     props->tie("environment/rel-wind-speed-kts",
 436                 SGRawValuePointer<double>(&rel_wind_speed_kts));
 437     props->tie("environment/in-to-wind",
 438         SGRawValuePointer<bool>(&in_to_wind));
 439     props->tie("controls/flols/wave-off-lights",
 440                 SGRawValuePointer<bool>(&wave_off_lights));
 441     props->tie("controls/elevators",
 442                 SGRawValuePointer<bool>(&elevators));
 443     props->tie("surface-positions/elevators-pos-norm",
 444                 SGRawValuePointer<double>(&pos_norm));
 445     props->tie("controls/constants/elevators/trans-time-s",
 446                 SGRawValuePointer<double>(&transition_time));
 447     props->tie("controls/constants/elevators/time-constant",
 448                 SGRawValuePointer<double>(&time_constant));
 449     props->tie("controls/jbd",
 450         SGRawValuePointer<bool>(&jbd));
 451     props->tie("surface-positions/jbd-pos-norm",
 452         SGRawValuePointer<double>(&jbd_pos_norm));
 453     props->tie("controls/constants/jbd/trans-time-s",
 454         SGRawValuePointer<double>(&jbd_transition_time));
 455     props->tie("controls/constants/jbd/time-constant",
 456         SGRawValuePointer<double>(&jbd_time_constant));
 457     props->tie("controls/turn-to-recovery-hdg",
 458         SGRawValuePointer<bool>(&turn_to_recovery_hdg));
 459     props->tie("controls/turn-to-base-course",
 460         SGRawValuePointer<bool>(&turn_to_base_course));
 461
 462
 463     props->setBoolValue("controls/flols/cut-lights", false);
 464     props->setBoolValue("controls/flols/wave-off-lights", false);
 465     props->setBoolValue("controls/flols/cond-datum-lights", true);
 466     props->setBoolValue("controls/crew", false);
 467     props->setStringValue("navaids/tacan/channel-ID", TACAN_channel_id.c_str());
 468     props->setStringValue("sign", sign.c_str());
 469     props->setBoolValue("controls/lighting/deck-lights", false);
 470     props->setDoubleValue("controls/lighting/flood-lights-red-norm", 0);
 471 }
 472
 473
 474 void FGAICarrier::unbind() {
 475     FGAIShip::unbind();
 476
 477     props->untie("velocities/true-airspeed-kt");
 478     props->untie("controls/flols/source-lights");
 479     props->untie("controls/flols/distance-m");
 480     props->untie("controls/flols/angle-degs");
 481     props->untie("controls/turn-to-launch-hdg");
 482     props->untie("velocities/speed-kts");
 483     props->untie("environment/wind-speed-true-kts");
 484     props->untie("environment/wind-from-true-degs");
 485     props->untie("environment/rel-wind-from-degs");
 486     props->untie("environment/rel-wind-speed-kts");
 487     props->untie("environment/in-to-wind");
 488     props->untie("controls/flols/wave-off-lights");
 489     props->untie("controls/elevators");
 490     props->untie("surface-positions/elevators-pos-norm");
 491     props->untie("controls/constants/elevators/trans-time-secs");
 492     props->untie("controls/constants/elevators/time-constant");
 493     props->untie("controls/jbd");
 494     props->untie("surface-positions/jbd/pos-norm");
 495     props->untie("controls/constants/jbd/trans-time-s");
 496     props->untie("controls/jbd-time-constant");
 497     props->untie("controls/mp-control");
 498     props->untie("controls/turn-to-recovery-hdg");
 499     props->untie("controls/turn-to-base-course");
 500 }
 501
 502
 503 bool FGAICarrier::getParkPosition(const string& id, SGGeod& geodPos,
 504                                   double& hdng, SGVec3d& uvw)
 505 {
 506
 507     // FIXME: does not yet cover rotation speeds.
 508     list<ParkPosition>::iterator it = ppositions.begin();
 509     while (it != ppositions.end()) {
 510         // Take either the specified one or the first one ...
 511         if ((*it).name == id || id.empty()) {
 512             ParkPosition ppos = *it;
 513             SGVec3d cartPos = getCartPosAt(ppos.offset);
 514             geodPos = SGGeod::fromCart(cartPos);
 515             hdng = hdg + ppos.heading_deg;
 516             double shdng = sin(ppos.heading_deg * SGD_DEGREES_TO_RADIANS);
 517             double chdng = cos(ppos.heading_deg * SGD_DEGREES_TO_RADIANS);
 518             double speed_fps = speed*1.6878099;
 519             uvw = SGVec3d(chdng*speed_fps, shdng*speed_fps, 0);
 520             return true;
 521         }
 522         ++it;
 523     }
 524
 525     return false;
 526 }
 527
 528 // find relative wind
 529 void FGAICarrier::UpdateWind( double dt) {
 530
 531     //get the surface wind speed and direction
 532     wind_from_deg = _surface_wind_from_deg_node->getDoubleValue();
 533     wind_speed_kts  = _surface_wind_speed_node->getDoubleValue();
 534
 535     //calculate the surface wind speed north and east in kts
 536     double wind_speed_from_north_kts = cos( wind_from_deg / SGD_RADIANS_TO_DEGREES )* wind_speed_kts ;
 537     double wind_speed_from_east_kts  = sin( wind_from_deg / SGD_RADIANS_TO_DEGREES )* wind_speed_kts ;
 538
 539     //calculate the carrier speed north and east in kts
 540     double speed_north_kts = cos( hdg / SGD_RADIANS_TO_DEGREES )* speed ;
 541     double speed_east_kts  = sin( hdg / SGD_RADIANS_TO_DEGREES )* speed ;
 542
 543     //calculate the relative wind speed north and east in kts
 544     double rel_wind_speed_from_east_kts = wind_speed_from_east_kts + speed_east_kts;
 545     double rel_wind_speed_from_north_kts = wind_speed_from_north_kts + speed_north_kts;
 546
 547     //combine relative speeds north and east to get relative windspeed in kts
 548     rel_wind_speed_kts = sqrt((rel_wind_speed_from_east_kts * rel_wind_speed_from_east_kts)
 549     + (rel_wind_speed_from_north_kts * rel_wind_speed_from_north_kts));
 550
 551     //calculate the relative wind direction
 552     rel_wind_from_deg = atan2(rel_wind_speed_from_east_kts, rel_wind_speed_from_north_kts)
 553                             * SG_RADIANS_TO_DEGREES;
 554
 555     //calculate rel wind
 556     rel_wind = rel_wind_from_deg - hdg;
 557     SG_NORMALIZE_RANGE(rel_wind, -180.0, 180.0);
 558
 559     //switch the wave-off lights
 560     if (InToWind())
 561        wave_off_lights = false;
 562     else
 563        wave_off_lights = true;
 564
 565     // cout << "rel wind: " << rel_wind << endl;
 566
 567 }// end update wind
 568
 569
 570 void FGAICarrier::TurnToLaunch(){
 571
 572     // calculate tgt heading
 573     if (wind_speed_kts < 3){
 574         tgt_heading = base_course;
 575     } else {
 576         tgt_heading = wind_from_deg;
 577     }
 578
 579     //calculate tgt speed
 580     double tgt_speed = 25 - wind_speed_kts;
 581     if (tgt_speed < 10)
 582         tgt_speed = 10;
 583
 584     //turn the carrier
 585     FGAIShip::TurnTo(tgt_heading);
 586     FGAIShip::AccelTo(tgt_speed);
 587
 588 }
 589
 590 void FGAICarrier::TurnToRecover(){
 591
 592     //these are the rules for adjusting heading to provide a relative wind
 593     //down the angled flightdeck
 594
 595     if (wind_speed_kts < 3){
 596         tgt_heading = base_course + 60;
 597     } else if (rel_wind < -9 && rel_wind >= -180){
 598         tgt_heading = wind_from_deg;
 599     } else if (rel_wind > -7 && rel_wind < 45){
 600         tgt_heading = wind_from_deg + 60;
 601     } else if (rel_wind >=45 && rel_wind < 180){
 602         tgt_heading = wind_from_deg + 45;
 603     } else
 604         tgt_heading = hdg;
 605
 606     SG_NORMALIZE_RANGE(tgt_heading, 0.0, 360.0);
 607
 608     //calculate tgt speed
 609     double tgt_speed = 26 - wind_speed_kts;
 610     if (tgt_speed < 10)
 611         tgt_speed = 10;
 612
 613     //turn the carrier
 614     FGAIShip::TurnTo(tgt_heading);
 615     FGAIShip::AccelTo(tgt_speed);
 616
 617 }
 618 void FGAICarrier::TurnToBase(){
 619
 620     //turn the carrier
 621     FGAIShip::TurnTo(base_course);
 622     FGAIShip::AccelTo(base_speed);
 623
 624 }
 625
 626
 627 void FGAICarrier::ReturnToBox(){
 628     double course, distance, az2;
 629
 630     //calculate the bearing and range of the initial position from the carrier
 631     geo_inverse_wgs_84(pos, mOpBoxPos, &course, &az2, &distance);
 632
 633     distance *= SG_METER_TO_NM;
 634
 635     //cout << "return course: " << course << " distance: " << distance << endl;
 636     //turn the carrier
 637     FGAIShip::TurnTo(course);
 638     FGAIShip::AccelTo(base_speed);
 639
 640     if (distance >= 1)
 641         returning = true;
 642     else
 643         returning = false;
 644
 645 } //  end turn to base
 646
 647
 648 bool FGAICarrier::OutsideBox() { //returns true if the carrier is outside operating box
 649
 650     if ( max_lat == 0 && min_lat == 0 && max_long == 0 && min_long == 0) {
 651         SG_LOG(SG_GENERAL, SG_DEBUG, "AICarrier: No Operating Box defined" );
 652         return false;
 653     }
 654
 655     if (mOpBoxPos.getLatitudeDeg() >= 0) { //northern hemisphere
 656         if (pos.getLatitudeDeg() >= mOpBoxPos.getLatitudeDeg() + max_lat)
 657             return true;
 658
 659         if (pos.getLatitudeDeg() <= mOpBoxPos.getLatitudeDeg() - min_lat)
 660             return true;
 661
 662     } else {                  //southern hemisphere
 663         if (pos.getLatitudeDeg() <= mOpBoxPos.getLatitudeDeg() - max_lat)
 664             return true;
 665
 666         if (pos.getLatitudeDeg() >= mOpBoxPos.getLatitudeDeg() + min_lat)
 667             return true;
 668     }
 669
 670     if (mOpBoxPos.getLongitudeDeg() >=0) { //eastern hemisphere
 671         if (pos.getLongitudeDeg() >= mOpBoxPos.getLongitudeDeg() + max_long)
 672             return true;
 673
 674         if (pos.getLongitudeDeg() <= mOpBoxPos.getLongitudeDeg() - min_long)
 675             return true;
 676
 677     } else {                 //western hemisphere
 678         if (pos.getLongitudeDeg() <= mOpBoxPos.getLongitudeDeg() - max_long)
 679             return true;
 680
 681         if (pos.getLongitudeDeg() >= mOpBoxPos.getLongitudeDeg() + min_long)
 682             return true;
 683     }
 684
 685     SG_LOG(SG_GENERAL, SG_DEBUG, "AICarrier: Inside Operating Box" );
 686     return false;
 687
 688 } // end OutsideBox
 689
 690
 691 bool FGAICarrier::InToWind() {
 692     in_to_wind = false;
 693
 694     if ( fabs(rel_wind) < 10 ){
 695         in_to_wind = true;
 696         return true;
 697     }
 698     return false;
 699 }
 700
 701
 702 void FGAICarrier::UpdateElevator(double dt, double transition_time) {
 703
 704     double step = 0;
 705
 706     if ((elevators && pos_norm >= 1 ) || (!elevators && pos_norm <= 0 ))
 707         return;
 708
 709     // move the elevators
 710     if ( elevators ) {
 711         step = dt/transition_time;
 712         if ( step > 1 )
 713             step = 1;
 714     } else {
 715         step = -dt/transition_time;
 716         if ( step < -1 )
 717             step = -1;
 718     }
 719     // assume a linear relationship
 720     raw_pos_norm += step;
 721
 722     //low pass filter
 723     pos_norm = (raw_pos_norm * time_constant) + (pos_norm * (1 - time_constant));
 724
 725     //sanitise the output
 726     if (raw_pos_norm >= 1) {
 727         raw_pos_norm = 1;
 728     } else if (raw_pos_norm <= 0) {
 729         raw_pos_norm = 0;
 730     }
 731     return;
 732
 733 } // end UpdateElevator
 734
 735 void FGAICarrier::UpdateJBD(double dt, double jbd_transition_time) {
 736
 737     string launchbar_state = _launchbar_state_node->getStringValue();
 738     double step = 0;
 739
 740     if (launchbar_state == "Engaged"){
 741         jbd = true;
 742     } else {
 743         jbd = false;
 744     }
 745
 746     if (( jbd && jbd_pos_norm >= 1 ) || ( !jbd && jbd_pos_norm <= 0 )){
 747         return;
 748     }
 749
 750     // move the jbds
 751     if ( jbd ) {
 752         step = dt/jbd_transition_time;
 753         if ( step > 1 )
 754             step = 1;
 755     } else {
 756         step = -dt/jbd_transition_time;
 757         if ( step < -1 )
 758             step = -1;
 759     }
 760
 761     // assume a linear relationship
 762     raw_jbd_pos_norm += step;
 763
 764     //low pass filter
 765     jbd_pos_norm = (raw_jbd_pos_norm * jbd_time_constant) + (jbd_pos_norm * (1 - jbd_time_constant));
 766
 767     //sanitise the output
 768     if (jbd_pos_norm >= 1) {
 769         jbd_pos_norm = 1;
 770     } else if (jbd_pos_norm <= 0) {
 771         jbd_pos_norm = 0;
 772     }
 773
 774     return;
 775
 776 } // end UpdateJBD