src/Instrumentation/dclgps.cxx

   1 // dclgps.cxx - a class to extend the operation of FG's current GPS
   2 // code, and provide support for a KLN89-specific instrument.  It
   3 // is envisioned that eventually this file and class will be split
   4 // up between current FG code and new KLN89-specific code and removed.
   5 //
   6 // Written by David Luff, started 2005.
   7 //
   8 // Copyright (C) 2005 - David C Luff - david.luff@nottingham.ac.uk
   9 //
  10 // This program is free software; you can redistribute it and/or
  11 // modify it under the terms of the GNU General Public License as
  12 // published by the Free Software Foundation; either version 2 of the
  13 // License, or (at your option) any later version.
  14 //
  15 // This program is distributed in the hope that it will be useful, but
  16 // WITHOUT ANY WARRANTY; without even the implied warranty of
  17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 // General Public License for more details.
  19 //
  20 // You should have received a copy of the GNU General Public License
  21 // along with this program; if not, write to the Free Software
  22 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 //
  24 // $Id$
  25
  26 #include "dclgps.hxx"
  27
  28 #include <simgear/sg_inlines.h>
  29 #include <iostream>
  30 SG_USING_STD(cout);
  31
  32 //using namespace std;
  33
  34 // Command callbacks for FlightGear
  35
  36 static bool do_kln89_msg_pressed(const SGPropertyNode* arg) {
  37         //cout << "do_kln89_msg_pressed called!\n";
  38         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  39         gps->MsgPressed();
  40         return(true);
  41 }
  42
  43 static bool do_kln89_obs_pressed(const SGPropertyNode* arg) {
  44         //cout << "do_kln89_obs_pressed called!\n";
  45         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  46         gps->OBSPressed();
  47         return(true);
  48 }
  49
  50 static bool do_kln89_alt_pressed(const SGPropertyNode* arg) {
  51         //cout << "do_kln89_alt_pressed called!\n";
  52         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  53         gps->AltPressed();
  54         return(true);
  55 }
  56
  57 static bool do_kln89_nrst_pressed(const SGPropertyNode* arg) {
  58         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  59         gps->NrstPressed();
  60         return(true);
  61 }
  62
  63 static bool do_kln89_dto_pressed(const SGPropertyNode* arg) {
  64         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  65         gps->DtoPressed();
  66         return(true);
  67 }
  68
  69 static bool do_kln89_clr_pressed(const SGPropertyNode* arg) {
  70         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  71         gps->ClrPressed();
  72         return(true);
  73 }
  74
  75 static bool do_kln89_ent_pressed(const SGPropertyNode* arg) {
  76         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  77         gps->EntPressed();
  78         return(true);
  79 }
  80
  81 static bool do_kln89_crsr_pressed(const SGPropertyNode* arg) {
  82         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  83         gps->CrsrPressed();
  84         return(true);
  85 }
  86
  87 static bool do_kln89_knob1left1(const SGPropertyNode* arg) {
  88         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  89         gps->Knob1Left1();
  90         return(true);
  91 }
  92
  93 static bool do_kln89_knob1right1(const SGPropertyNode* arg) {
  94         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
  95         gps->Knob1Right1();
  96         return(true);
  97 }
  98
  99 static bool do_kln89_knob2left1(const SGPropertyNode* arg) {
 100         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
 101         gps->Knob2Left1();
 102         return(true);
 103 }
 104
 105 static bool do_kln89_knob2right1(const SGPropertyNode* arg) {
 106         DCLGPS* gps = (DCLGPS*)globals->get_subsystem("kln89");
 107         gps->Knob2Right1();
 108         return(true);
 109 }
 110
 111 // End command callbacks
 112
 113 GPSWaypoint::GPSWaypoint() {
 114     appType = GPS_APP_NONE;
 115 }
 116
 117 GPSWaypoint::~GPSWaypoint() {}
 118
 119 string GPSWaypoint::GetAprId() {
 120         if(appType == GPS_IAF) return(id + 'i');
 121         else if(appType == GPS_FAF) return(id + 'f');
 122         else if(appType == GPS_MAP) return(id + 'm');
 123         else if(appType == GPS_MAHP) return(id + 'h');
 124         else return(id);
 125 }
 126
 127 ostream& operator << (ostream& os, GPSAppWpType type) {
 128         switch(type) {
 129                 case(GPS_IAF):       return(os << "IAF");
 130                 case(GPS_IAP):       return(os << "IAP");
 131                 case(GPS_FAF):       return(os << "FAF");
 132                 case(GPS_MAP):       return(os << "MAP");
 133                 case(GPS_MAHP):      return(os << "MAHP");
 134                 case(GPS_HDR):       return(os << "HEADER");
 135                 case(GPS_FENCE):     return(os << "FENCE");
 136                 case(GPS_APP_NONE):  return(os << "NONE");
 137         }
 138         return(os << "ERROR - Unknown switch in GPSAppWpType operator << ");
 139 }
 140
 141 FGIAP::FGIAP() {
 142 }
 143
 144 FGIAP::~FGIAP() {
 145 }
 146
 147 FGNPIAP::FGNPIAP() {
 148 }
 149
 150 FGNPIAP::~FGNPIAP() {
 151 }
 152
 153 GPSPage::GPSPage(DCLGPS* parent) {
 154         _parent = parent;
 155         _subPage = 0;
 156 }
 157
 158 GPSPage::~GPSPage() {
 159 }
 160
 161 void GPSPage::Update(double dt) {}
 162
 163 void GPSPage::Knob1Left1() {}
 164 void GPSPage::Knob1Right1() {}
 165
 166 void GPSPage::Knob2Left1() {
 167         _parent->_activePage->LooseFocus();
 168         _subPage--;
 169         if(_subPage < 0) _subPage = _nSubPages - 1;
 170 }
 171
 172 void GPSPage::Knob2Right1() {
 173         _parent->_activePage->LooseFocus();
 174         _subPage++;
 175         if(_subPage >= _nSubPages) _subPage = 0;
 176 }
 177
 178 void GPSPage::CrsrPressed() {}
 179 void GPSPage::EntPressed() {}
 180 void GPSPage::ClrPressed() {}
 181 void GPSPage::DtoPressed() {}
 182 void GPSPage::NrstPressed() {}
 183 void GPSPage::AltPressed() {}
 184 void GPSPage::OBSPressed() {}
 185 void GPSPage::MsgPressed() {}
 186
 187 string GPSPage::GPSitoa(int n) {
 188         char buf[4];
 189         // TODO - sanity check n!
 190         sprintf(buf, "%i", n);
 191         string s = buf;
 192         return(s);
 193 }
 194
 195 void GPSPage::CleanUp() {}
 196 void GPSPage::LooseFocus() {}
 197 void GPSPage::SetId(string s) {}
 198 string GPSPage::GetId() { return(""); }
 199
 200 // ------------------------------------------------------------------------------------- //
 201
 202 DCLGPS::DCLGPS(RenderArea2D* instrument) {
 203         _instrument = instrument;
 204         _nFields = 1;
 205         _maxFields = 2;
 206         _pages.clear();
 207
 208         // Units - lets default to US units - FG can set them to other units from config during startup if desired.
 209         _altUnits = GPS_ALT_UNITS_FT;
 210         _baroUnits = GPS_PRES_UNITS_IN;
 211         _velUnits = GPS_VEL_UNITS_KT;
 212         _distUnits = GPS_DIST_UNITS_NM;
 213
 214         _lon_node = fgGetNode("/instrumentation/gps/indicated-longitude-deg", true);
 215         _lat_node = fgGetNode("/instrumentation/gps/indicated-latitude-deg", true);
 216         _alt_node = fgGetNode("/instrumentation/gps/indicated-altitude-ft", true);
 217         _grnd_speed_node = fgGetNode("/instrumentation/gps/indicated-ground-speed-kt", true);
 218         _true_track_node = fgGetNode("/instrumentation/gps/indicated-track-true-deg", true);
 219         _mag_track_node = fgGetNode("/instrumentation/gps/indicated-track-magnetic-deg", true);
 220
 221         // Use FG's position values at construction in case FG's gps has not run first update yet.
 222         _lon = fgGetDouble("/position/longitude-deg") * SG_DEGREES_TO_RADIANS;
 223         _lat = fgGetDouble("/position/latitude-deg") * SG_DEGREES_TO_RADIANS;
 224         _alt = fgGetDouble("/position/altitude-ft");
 225         // Note - we can depriciate _gpsLat and _gpsLon if we implement error handling in FG
 226         // gps code and not our own.
 227         _gpsLon = _lon;
 228         _gpsLat = _lat;
 229         _checkLon = _gpsLon;
 230         _checkLat = _gpsLat;
 231         _groundSpeed_ms = 0.0;
 232         _groundSpeed_kts = 0.0;
 233         _track = 0.0;
 234         _magTrackDeg = 0.0;
 235
 236         // Sensible defaults.  These can be overriden by derived classes if desired.
 237         _cdiScales.clear();
 238         _cdiScales.push_back(5.0);
 239         _cdiScales.push_back(1.0);
 240         _cdiScales.push_back(0.3);
 241         _currentCdiScaleIndex = 0;
 242         _targetCdiScaleIndex = 0;
 243         _sourceCdiScaleIndex = 0;
 244         _cdiScaleTransition = false;
 245         _currentCdiScale = 5.0;
 246
 247         _cleanUpPage = -1;
 248
 249         _activeWaypoint.id.clear();
 250         _dist2Act = 0.0;
 251         _crosstrackDist = 0.0;
 252         _headingBugTo = true;
 253         _navFlagged = true;
 254         _waypointAlert = false;
 255         _departed = false;
 256         _departureTimeString = "----";
 257         _elapsedTime = 0.0;
 258
 259         // Configuration Initialisation
 260         // Should this be in kln89.cxx ?
 261         _turnAnticipationEnabled = false;
 262         _suaAlertEnabled = false;
 263         _altAlertEnabled = false;
 264
 265         _time = new SGTime;
 266
 267         _messageStack.clear();
 268
 269         _dto = false;
 270
 271         _approachLoaded = false;
 272         _approachArm = false;
 273         _approachReallyArmed = false;
 274         _approachActive = false;
 275         _approachFP = new GPSFlightPlan;
 276 }
 277
 278 DCLGPS::~DCLGPS() {
 279         delete _time;
 280         for(gps_waypoint_map_iterator itr = _waypoints.begin(); itr != _waypoints.end(); ++itr) {
 281                 for(unsigned int i = 0; i < (*itr).second.size(); ++i) {
 282                         delete(((*itr).second)[i]);
 283                 }
 284         }
 285         delete _approachFP;             // Don't need to delete the waypoints inside since they point to
 286                                                         // the waypoints in the approach database.
 287         // TODO - may need to delete the approach database!!
 288 }
 289
 290 void DCLGPS::draw() {
 291         //cout << "draw called!\n";
 292         _instrument->draw();
 293 }
 294
 295 void DCLGPS::init() {
 296         globals->get_commands()->addCommand("kln89_msg_pressed", do_kln89_msg_pressed);
 297         globals->get_commands()->addCommand("kln89_obs_pressed", do_kln89_obs_pressed);
 298         globals->get_commands()->addCommand("kln89_alt_pressed", do_kln89_alt_pressed);
 299         globals->get_commands()->addCommand("kln89_nrst_pressed", do_kln89_nrst_pressed);
 300         globals->get_commands()->addCommand("kln89_dto_pressed", do_kln89_dto_pressed);
 301         globals->get_commands()->addCommand("kln89_clr_pressed", do_kln89_clr_pressed);
 302         globals->get_commands()->addCommand("kln89_ent_pressed", do_kln89_ent_pressed);
 303         globals->get_commands()->addCommand("kln89_crsr_pressed", do_kln89_crsr_pressed);
 304         globals->get_commands()->addCommand("kln89_knob1left1", do_kln89_knob1left1);
 305         globals->get_commands()->addCommand("kln89_knob1right1", do_kln89_knob1right1);
 306         globals->get_commands()->addCommand("kln89_knob2left1", do_kln89_knob2left1);
 307         globals->get_commands()->addCommand("kln89_knob2right1", do_kln89_knob2right1);
 308
 309         // Build the GPS-specific databases.
 310         // TODO - consider splitting into real life GPS database regions - eg Americas, Europe etc.
 311         // Note that this needs to run after FG's airport and nav databases are up and running
 312         _waypoints.clear();
 313         const airport_list* apts = globals->get_airports()->getAirportList();
 314         for(unsigned int i = 0; i < apts->size(); ++i) {
 315                 FGAirport* a = (*apts)[i];
 316                 GPSWaypoint* w = new GPSWaypoint;
 317                 w->id = a->getId();
 318                 w->lat = a->getLatitude() * SG_DEGREES_TO_RADIANS;
 319                 w->lon = a->getLongitude() * SG_DEGREES_TO_RADIANS;
 320                 w->type = GPS_WP_APT;
 321                 gps_waypoint_map_iterator wtr = _waypoints.find(a->getId());
 322                 if(wtr == _waypoints.end()) {
 323                         gps_waypoint_array arr;
 324                         arr.push_back(w);
 325                         _waypoints[w->id] = arr;
 326                 } else {
 327                         wtr->second.push_back(w);
 328                 }
 329         }
 330         nav_map_type navs = globals->get_navlist()->get_navaids();
 331         for(nav_map_iterator itr = navs.begin(); itr != navs.end(); ++itr) {
 332                 nav_list_type nlst = itr->second;
 333                 for(unsigned int i = 0; i < nlst.size(); ++i) {
 334                         FGNavRecord* n = nlst[i];
 335                         if(n->get_fg_type() == FG_NAV_VOR || n->get_fg_type() == FG_NAV_NDB) {  // We don't bother with ILS etc.
 336                                 GPSWaypoint* w = new GPSWaypoint;
 337                                 w->id = n->get_ident();
 338                                 w->lat = n->get_lat() * SG_DEGREES_TO_RADIANS;
 339                                 w->lon = n->get_lon() * SG_DEGREES_TO_RADIANS;
 340                                 w->type = (n->get_fg_type() == FG_NAV_VOR ? GPS_WP_VOR : GPS_WP_NDB);
 341                                 gps_waypoint_map_iterator wtr = _waypoints.find(n->get_ident());
 342                                 if(wtr == _waypoints.end()) {
 343                                         gps_waypoint_array arr;
 344                                         arr.push_back(w);
 345                                         _waypoints[w->id] = arr;
 346                                 } else {
 347                                         wtr->second.push_back(w);
 348                                 }
 349                         }
 350                 }
 351         }
 352         const fix_map_type* fixes = globals->get_fixlist()->getFixList();
 353         for(fix_map_const_iterator itr = fixes->begin(); itr != fixes->end(); ++itr) {
 354                 FGFix f = itr->second;
 355                 GPSWaypoint* w = new GPSWaypoint;
 356                 w->id = f.get_ident();
 357                 w->lat = f.get_lat() * SG_DEGREES_TO_RADIANS;
 358                 w->lon = f.get_lon() * SG_DEGREES_TO_RADIANS;
 359                 w->type = GPS_WP_INT;
 360                 gps_waypoint_map_iterator wtr = _waypoints.find(f.get_ident());
 361                 if(wtr == _waypoints.end()) {
 362                         gps_waypoint_array arr;
 363                         arr.push_back(w);
 364                         _waypoints[w->id] = arr;
 365                 } else {
 366                         wtr->second.push_back(w);
 367                 }
 368         }
 369         // TODO - add USR waypoints as well.
 370
 371         // Not sure if this should be here, but OK for now.
 372         CreateDefaultFlightPlans();
 373
 374         // Hack - hardwire some instrument approaches for testing.
 375         // TODO - read these from file - either all at startup or as needed.
 376         FGNPIAP* iap = new FGNPIAP;
 377         iap->_id = "KHWD";
 378         iap->_name = "VOR/DME OR GPS-B";
 379         iap->_abbrev = "VOR/D";
 380         iap->_rwyStr = "B";
 381         iap->_IAF.clear();
 382         iap->_IAP.clear();
 383         iap->_MAP.clear();
 384         // -------
 385         GPSWaypoint* wp = new GPSWaypoint;
 386         wp->id = "SUNOL";
 387         bool multi;
 388         // Nasty using the find any function here, but it saves converting data from FGFix etc.
 389         const GPSWaypoint* fp = FindFirstById(wp->id, multi, true);
 390         *wp = *fp;
 391         wp->appType = GPS_IAF;
 392         iap->_IAF.push_back(wp);
 393         // -------
 394         wp = new GPSWaypoint;
 395         wp->id = "MABRY";
 396         fp = FindFirstById(wp->id, multi, true);
 397         *wp = *fp;
 398         wp->appType = GPS_IAF;
 399         iap->_IAF.push_back(wp);
 400         // -------
 401         wp = new GPSWaypoint;
 402         wp->id = "IMPLY";
 403         fp = FindFirstById(wp->id, multi, true);
 404         *wp = *fp;
 405         wp->appType = GPS_IAP;
 406         iap->_IAP.push_back(wp);
 407         // -------
 408         wp = new GPSWaypoint;
 409         wp->id = "DECOT";
 410         fp = FindFirstById(wp->id, multi, true);
 411         *wp = *fp;
 412         wp->appType = GPS_FAF;
 413         iap->_IAP.push_back(wp);
 414         // -------
 415         wp = new GPSWaypoint;
 416         wp->id = "MAPVV";
 417         fp = FindFirstById(wp->id, multi, true);
 418         *wp = *fp;
 419         wp->appType = GPS_MAP;
 420         iap->_IAP.push_back(wp);
 421         // -------
 422         wp = new GPSWaypoint;
 423         wp->id = "OAK";
 424         fp = FindFirstById(wp->id, multi, true);
 425         *wp = *fp;
 426         wp->appType = GPS_MAHP;
 427         iap->_MAP.push_back(wp);
 428         // -------
 429         _np_iap[iap->_id].push_back(iap);
 430         // -----------------------
 431         // -----------------------
 432         iap = new FGNPIAP;
 433         iap->_id = "KHWD";
 434         iap->_name = "VOR OR GPS-A";
 435         iap->_abbrev = "VOR-";
 436         iap->_rwyStr = "A";
 437         iap->_IAF.clear();
 438         iap->_IAP.clear();
 439         iap->_MAP.clear();
 440         // -------
 441         wp = new GPSWaypoint;
 442         wp->id = "SUNOL";
 443         // Nasty using the find any function here, but it saves converting data from FGFix etc.
 444         fp = FindFirstById(wp->id, multi, true);
 445         *wp = *fp;
 446         wp->appType = GPS_IAF;
 447         iap->_IAF.push_back(wp);
 448         // -------
 449         wp = new GPSWaypoint;
 450         wp->id = "MABRY";
 451         fp = FindFirstById(wp->id, multi, true);
 452         *wp = *fp;
 453         wp->appType = GPS_IAF;
 454         iap->_IAF.push_back(wp);
 455         // -------
 456         wp = new GPSWaypoint;
 457         wp->id = "IMPLY";
 458         fp = FindFirstById(wp->id, multi, true);
 459         *wp = *fp;
 460         wp->appType = GPS_IAP;
 461         iap->_IAP.push_back(wp);
 462         // -------
 463         wp = new GPSWaypoint;
 464         wp->id = "DECOT";
 465         fp = FindFirstById(wp->id, multi, true);
 466         *wp = *fp;
 467         wp->appType = GPS_FAF;
 468         iap->_IAP.push_back(wp);
 469         // -------
 470         wp = new GPSWaypoint;
 471         wp->id = "MAPVV";
 472         fp = FindFirstById(wp->id, multi, true);
 473         *wp = *fp;
 474         wp->appType = GPS_MAP;
 475         iap->_IAP.push_back(wp);
 476         // -------
 477         wp = new GPSWaypoint;
 478         wp->id = "OAK";
 479         fp = FindFirstById(wp->id, multi, true);
 480         *wp = *fp;
 481         wp->appType = GPS_MAHP;
 482         iap->_MAP.push_back(wp);
 483         // -------
 484         _np_iap[iap->_id].push_back(iap);
 485         // ------------------
 486         // ------------------
 487         /*
 488         // Ugh - don't load this one - the waypoints required aren't in fix.dat.gz - result: program crash!
 489         // TODO - make the IAP loader robust to absent waypoints.
 490         iap = new FGNPIAP;
 491         iap->_id = "KHWD";
 492         iap->_name = "GPS RWY 28L";
 493         iap->_abbrev = "GPS";
 494         iap->_rwyStr = "28L";
 495         iap->_IAF.clear();
 496         iap->_IAP.clear();
 497         iap->_MAP.clear();
 498         // -------
 499         wp = new GPSWaypoint;
 500         wp->id = "SUNOL";
 501         // Nasty using the find any function here, but it saves converting data from FGFix etc.
 502         fp = FindFirstById(wp->id, multi, true);
 503         *wp = *fp;
 504         wp->appType = GPS_IAF;
 505         iap->_IAF.push_back(wp);
 506         // -------
 507         wp = new GPSWaypoint;
 508         wp->id = "SJC";
 509         fp = FindFirstById(wp->id, multi, true);
 510         *wp = *fp;
 511         wp->appType = GPS_IAF;
 512         iap->_IAF.push_back(wp);
 513         // -------
 514         wp = new GPSWaypoint;
 515         wp->id = "JOCPI";
 516         fp = FindFirstById(wp->id, multi, true);
 517         *wp = *fp;
 518         wp->appType = GPS_IAP;
 519         iap->_IAP.push_back(wp);
 520         // -------
 521         wp = new GPSWaypoint;
 522         wp->id = "SUDGE";
 523         fp = FindFirstById(wp->id, multi, true);
 524         *wp = *fp;
 525         wp->appType = GPS_FAF;
 526         iap->_IAP.push_back(wp);
 527         // -------
 528         wp = new GPSWaypoint;
 529         wp->id = "RW28L";
 530         wp->appType = GPS_MAP;
 531         if(wp->id.substr(0, 2) == "RW" && wp->appType == GPS_MAP) {
 532                 // Assume that this is a missed-approach point based on the runway number
 533                 // Get the runway threshold location etc
 534         } else {
 535                 fp = FindFirstById(wp->id, multi, true);
 536                 if(fp == NULL) {
 537                         cout << "Failed to find waypoint " << wp->id << " in database...\n";
 538                 } else {
 539                         *wp = *fp;
 540                 }
 541         }
 542         iap->_IAP.push_back(wp);
 543         // -------
 544         wp = new GPSWaypoint;
 545         wp->id = "OAK";
 546         fp = FindFirstById(wp->id, multi, true);
 547         *wp = *fp;
 548         wp->appType = GPS_MAHP;
 549         iap->_MAP.push_back(wp);
 550         // -------
 551         _np_iap[iap->_id].push_back(iap);
 552         */
 553         iap = new FGNPIAP;
 554         iap->_id = "C83";
 555         iap->_name = "GPS RWY 30";
 556         iap->_abbrev = "GPS";
 557         iap->_rwyStr = "30";
 558         iap->_IAF.clear();
 559         iap->_IAP.clear();
 560         iap->_MAP.clear();
 561         // -------
 562         wp = new GPSWaypoint;
 563         wp->id = "PATYY";
 564         // Nasty using the find any function here, but it saves converting data from FGFix etc.
 565         fp = FindFirstById(wp->id, multi, true);
 566         *wp = *fp;
 567         wp->appType = GPS_IAF;
 568         iap->_IAF.push_back(wp);
 569         // -------
 570         wp = new GPSWaypoint;
 571         wp->id = "TRACY";
 572         fp = FindFirstById(wp->id, multi, true);
 573         *wp = *fp;
 574         wp->appType = GPS_IAF;
 575         iap->_IAF.push_back(wp);
 576         // -------
 577         wp = new GPSWaypoint;
 578         wp->id = "TRACY";
 579         fp = FindFirstById(wp->id, multi, true);
 580         *wp = *fp;
 581         wp->appType = GPS_IAP;
 582         iap->_IAP.push_back(wp);
 583         // -------
 584         wp = new GPSWaypoint;
 585         wp->id = "BABPI";
 586         fp = FindFirstById(wp->id, multi, true);
 587         *wp = *fp;
 588         wp->appType = GPS_FAF;
 589         iap->_IAP.push_back(wp);
 590         // -------
 591         wp = new GPSWaypoint;
 592         wp->id = "AMOSY";
 593         wp->appType = GPS_MAP;
 594         if(wp->id.substr(0, 2) == "RW" && wp->appType == GPS_MAP) {
 595                 // Assume that this is a missed-approach point based on the runway number
 596                 // TODO: Get the runway threshold location etc
 597                 cout << "TODO - implement missed-approach point based on rwy no.\n";
 598         } else {
 599                 fp = FindFirstById(wp->id, multi, true);
 600                 if(fp == NULL) {
 601                         cout << "Failed to find waypoint " << wp->id << " in database...\n";
 602                 } else {
 603                         *wp = *fp;
 604                         wp->appType = GPS_MAP;
 605                 }
 606         }
 607         iap->_IAP.push_back(wp);
 608         // -------
 609         wp = new GPSWaypoint;
 610         wp->id = "HAIRE";
 611         fp = FindFirstById(wp->id, multi, true);
 612         *wp = *fp;
 613         wp->appType = GPS_MAHP;
 614         iap->_MAP.push_back(wp);
 615         // -------
 616         _np_iap[iap->_id].push_back(iap);
 617 }
 618
 619 void DCLGPS::bind() {
 620         fgTie("/instrumentation/gps/waypoint-alert", this, &DCLGPS::GetWaypointAlert);
 621         fgTie("/instrumentation/gps/leg-mode", this, &DCLGPS::GetLegMode);
 622         fgTie("/instrumentation/gps/obs-mode", this, &DCLGPS::GetOBSMode);
 623         fgTie("/instrumentation/gps/approach-arm", this, &DCLGPS::GetApproachArm);
 624         fgTie("/instrumentation/gps/approach-active", this, &DCLGPS::GetApproachActive);
 625         fgTie("/instrumentation/gps/cdi-deflection", this, &DCLGPS::GetCDIDeflection);
 626         fgTie("/instrumentation/gps/to-flag", this, &DCLGPS::GetToFlag);
 627 }
 628
 629 void DCLGPS::unbind() {
 630         fgUntie("/instrumentation/gps/waypoint-alert");
 631         fgUntie("/instrumentation/gps/leg-mode");
 632         fgUntie("/instrumentation/gps/obs-mode");
 633         fgUntie("/instrumentation/gps/approach-arm");
 634         fgUntie("/instrumentation/gps/approach-active");
 635         fgUntie("/instrumentation/gps/cdi-deflection");
 636 }
 637
 638 void DCLGPS::update(double dt) {
 639         //cout << "update called!\n";
 640
 641         _lon = _lon_node->getDoubleValue() * SG_DEGREES_TO_RADIANS;
 642         _lat = _lat_node->getDoubleValue() * SG_DEGREES_TO_RADIANS;
 643         _alt = _alt_node->getDoubleValue();
 644         _groundSpeed_kts = _grnd_speed_node->getDoubleValue();
 645         _groundSpeed_ms = _groundSpeed_kts * 0.5144444444;
 646         _track = _true_track_node->getDoubleValue();
 647         _magTrackDeg = _mag_track_node->getDoubleValue();
 648         // Note - we can depriciate _gpsLat and _gpsLon if we implement error handling in FG
 649         // gps code and not our own.
 650         _gpsLon = _lon;
 651         _gpsLat = _lat;
 652         // Check for abnormal position slew
 653         if(GetGreatCircleDistance(_gpsLat, _gpsLon, _checkLat, _checkLon) > 1.0) {
 654                 OrientateToActiveFlightPlan();
 655         }
 656         _checkLon = _gpsLon;
 657         _checkLat = _gpsLat;
 658
 659         if(!_departed) {
 660                 if(_groundSpeed_kts > 30.0) {
 661                         _departed = true;
 662                         string th = fgGetString("/instrumentation/clock/indicated-hour");
 663                         string tm = fgGetString("/instrumentation/clock/indicated-min");
 664                         if(th.size() == 1) th = "0" + th;
 665                         if(tm.size() == 1) tm = "0" + tm;
 666                         _departureTimeString = th + tm;
 667                 }
 668         } else {
 669                 // TODO - check - is this prone to drift error over time?
 670                 // Should we difference the departure and current times?
 671                 // What about when the user resets the time of day from the menu?
 672                 _elapsedTime += dt;
 673         }
 674
 675         _time->update(_gpsLon * SG_DEGREES_TO_RADIANS, _gpsLat * SG_DEGREES_TO_RADIANS, 0, 0);
 676         // FIXME - currently all the below assumes leg mode and no DTO or OBS cancelled.
 677         if(_activeFP->IsEmpty()) {
 678                 // Not sure if we need to reset these each update or only when fp altered
 679                 _activeWaypoint.id.clear();
 680                 _navFlagged = true;
 681         } else if(_activeFP->waypoints.size() == 1) {
 682                 _activeWaypoint.id.clear();
 683         } else {
 684                 _navFlagged = false;
 685                 if(_activeWaypoint.id.empty() || _fromWaypoint.id.empty()) {
 686                         //cout << "Error, in leg mode with flightplan of 2 or more waypoints, but either active or from wp is NULL!\n";
 687                         OrientateToActiveFlightPlan();
 688                 }
 689
 690                 // Approach stuff
 691                 if(_approachLoaded) {
 692                         if(!_approachReallyArmed && !_approachActive) {
 693                                 // arm if within 30nm of airport.
 694                                 // TODO - let user cancel approach arm using external GPS-APR switch
 695                                 bool multi;
 696                                 const FGAirport* ap = FindFirstAptById(_approachID, multi, true);
 697                                 if(ap != NULL) {
 698                                         double d = GetGreatCircleDistance(_gpsLat, _gpsLon, ap->getLatitude() * SG_DEGREES_TO_RADIANS, ap->getLongitude() * SG_DEGREES_TO_RADIANS);
 699                                         if(d <= 30) {
 700                                                 _approachArm = true;
 701                                                 _approachReallyArmed = true;
 702                                                 _messageStack.push_back("*Press ALT To Set Baro");
 703                                                 // Not sure what we do if the user has already set CDI to 0.3 nm?
 704                                                 _targetCdiScaleIndex = 1;
 705                                                 if(_currentCdiScaleIndex == 1) {
 706                                                         // No problem!
 707                                                 } else if(_currentCdiScaleIndex == 0) {
 708                                                         _sourceCdiScaleIndex = 0;
 709                                                         _cdiScaleTransition = true;
 710                                                         _cdiTransitionTime = 30.0;
 711                                                         _currentCdiScale = _cdiScales[_currentCdiScaleIndex];
 712                                                 }
 713                                         }
 714                                 }
 715                         } else {
 716                                 // Check for approach active - we can only activate approach if it is really armed.
 717                                 if(_activeWaypoint.appType == GPS_FAF) {
 718                                         //cout << "Active waypoint is FAF, id is " << _activeWaypoint.id << '\n';
 719                                         if(GetGreatCircleDistance(_gpsLat, _gpsLon, _activeWaypoint.lat, _activeWaypoint.lon) <= 2.0 && !_obsMode) {
 720                                                 // Assume heading is OK for now
 721                                                 _approachArm = false;   // TODO - check - maybe arm is left on when actv comes on?
 722                                                 _approachReallyArmed = false;
 723                                                 _approachActive = true;
 724                                                 _targetCdiScaleIndex = 2;
 725                                                 if(_currentCdiScaleIndex == 2) {
 726                                                         // No problem!
 727                                                 } else if(_currentCdiScaleIndex == 1) {
 728                                                         _sourceCdiScaleIndex = 1;
 729                                                         _cdiScaleTransition = true;
 730                                                         _cdiTransitionTime = 30.0;      // TODO - compress it if time to FAF < 30sec
 731                                                         _currentCdiScale = _cdiScales[_currentCdiScaleIndex];
 732                                                 } else {
 733                                                         // Abort going active?
 734                                                         _approachActive = false;
 735                                                 }
 736                                         }
 737                                 }
 738                         }
 739                 }
 740
 741                 // CDI scale transition stuff
 742                 if(_cdiScaleTransition) {
 743                         if(fabs(_currentCdiScale - _cdiScales[_targetCdiScaleIndex]) < 0.001) {
 744                                 _currentCdiScale = _cdiScales[_targetCdiScaleIndex];
 745                                 _currentCdiScaleIndex = _targetCdiScaleIndex;
 746                                 _cdiScaleTransition = false;
 747                         } else {
 748                                 double scaleDiff = (_targetCdiScaleIndex > _sourceCdiScaleIndex
 749                                                     ? _cdiScales[_sourceCdiScaleIndex] - _cdiScales[_targetCdiScaleIndex]
 750                                                                         : _cdiScales[_targetCdiScaleIndex] - _cdiScales[_sourceCdiScaleIndex]);
 751                                 //cout << "ScaleDiff = " << scaleDiff << '\n';
 752                                 if(_targetCdiScaleIndex > _sourceCdiScaleIndex) {
 753                                         // Scaling down eg. 5nm -> 1nm
 754                                         _currentCdiScale -= (scaleDiff * dt / _cdiTransitionTime);
 755                                         if(_currentCdiScale < _cdiScales[_targetCdiScaleIndex]) {
 756                                                 _currentCdiScale = _cdiScales[_targetCdiScaleIndex];
 757                                                 _currentCdiScaleIndex = _targetCdiScaleIndex;
 758                                                 _cdiScaleTransition = false;
 759                                         }
 760                                 } else {
 761                                         _currentCdiScale += (scaleDiff * dt / _cdiTransitionTime);
 762                                         if(_currentCdiScale > _cdiScales[_targetCdiScaleIndex]) {
 763                                                 _currentCdiScale = _cdiScales[_targetCdiScaleIndex];
 764                                                 _currentCdiScaleIndex = _targetCdiScaleIndex;
 765                                                 _cdiScaleTransition = false;
 766                                         }
 767                                 }
 768                                 //cout << "_currentCdiScale = " << _currentCdiScale << '\n';
 769                         }
 770                 } else {
 771                         _currentCdiScale = _cdiScales[_currentCdiScaleIndex];
 772                 }
 773
 774
 775                 // Urgh - I've been setting the heading bug based on DTK,
 776                 // bug I think it should be based on heading re. active waypoint
 777                 // based on what the sim does after the final waypoint is passed.
 778                 // (DTK remains the same, but if track is held == DTK heading bug
 779                 // reverses to from once wp is passed).
 780                 /*
 781                 if(_fromWaypoint != NULL) {
 782                         // TODO - how do we handle the change of track with distance over long legs?
 783                         _dtkTrue = GetGreatCircleCourse(_fromWaypoint->lat, _fromWaypoint->lon, _activeWaypoint->lat, _activeWaypoint->lon) * SG_RADIANS_TO_DEGREES;
 784                         _dtkMag = GetMagHeadingFromTo(_fromWaypoint->lat, _fromWaypoint->lon, _activeWaypoint->lat, _activeWaypoint->lon);
 785                         // Don't change the heading bug if speed is too low otherwise it flickers to/from at rest
 786                         if(_groundSpeed_ms > 5) {
 787                                 //cout << "track = " << _track << ", dtk = " << _dtkTrue << '\n';
 788                                 double courseDev = _track - _dtkTrue;
 789                                 //cout << "courseDev = " << courseDev << ", normalized = ";
 790                                 SG_NORMALIZE_RANGE(courseDev, -180.0, 180.0);
 791                                 //cout << courseDev << '\n';
 792                                 _headingBugTo = (fabs(courseDev) > 90.0 ? false : true);
 793                         }
 794                 } else {
 795                         _dtkTrue = 0.0;
 796                         _dtkMag = 0.0;
 797                         // TODO - in DTO operation the position of initiation of DTO defines the "from waypoint".
 798                 }
 799                 */
 800                 if(!_activeWaypoint.id.empty()) {
 801                         double hdgTrue = GetGreatCircleCourse(_gpsLat, _gpsLon, _activeWaypoint.lat, _activeWaypoint.lon) * SG_RADIANS_TO_DEGREES;
 802                         if(_groundSpeed_ms > 5) {
 803                                 //cout << "track = " << _track << ", hdgTrue = " << hdgTrue << '\n';
 804                                 double courseDev = _track - hdgTrue;
 805                                 //cout << "courseDev = " << courseDev << ", normalized = ";
 806                                 SG_NORMALIZE_RANGE(courseDev, -180.0, 180.0);
 807                                 //cout << courseDev << '\n';
 808                                 _headingBugTo = (fabs(courseDev) > 90.0 ? false : true);
 809                         }
 810                         if(!_fromWaypoint.id.empty()) {
 811                                 _dtkTrue = GetGreatCircleCourse(_fromWaypoint.lat, _fromWaypoint.lon, _activeWaypoint.lat, _activeWaypoint.lon) * SG_RADIANS_TO_DEGREES;
 812                                 _dtkMag = GetMagHeadingFromTo(_fromWaypoint.lat, _fromWaypoint.lon, _activeWaypoint.lat, _activeWaypoint.lon);
 813                         } else {
 814                                 _dtkTrue = 0.0;
 815                                 _dtkMag = 0.0;
 816                         }
 817                 }
 818
 819                 _dist2Act = GetGreatCircleDistance(_gpsLat, _gpsLon, _activeWaypoint.lat, _activeWaypoint.lon) * SG_NM_TO_METER;
 820                 if(_groundSpeed_ms > 10.0) {
 821                         _eta = _dist2Act / _groundSpeed_ms;
 822                         if(_eta <= 36) {        // TODO - this is slightly different if turn anticipation is enabled.
 823                                 if(_headingBugTo) {
 824                                         _waypointAlert = true;  // TODO - not if the from flag is set.
 825                                 }
 826                         }
 827                         if(_eta < 60) {
 828                                 // Check if we should sequence to next leg.
 829                                 // Perhaps this should be done on distance instead, but 60s time (about 1 - 2 nm) seems reasonable for now.
 830                                 //double reverseHeading = GetGreatCircleCourse(_activeWaypoint->lat, _activeWaypoint->lon, _fromWaypoint->lat, _fromWaypoint->lon);
 831                                 // Hack - let's cheat and do it on heading bug for now.  TODO - that stops us 'cutting the corner'
 832                                 // when we happen to approach the inside turn of a waypoint - we should probably sequence at the midpoint
 833                                 // of the heading difference between legs in this instance.
 834                                 int idx = GetActiveWaypointIndex();
 835                                 bool finalLeg = (idx == (int)(_activeFP->waypoints.size()) - 1 ? true : false);
 836                                 bool finalDto = (_dto && idx == -1);    // Dto operation to a waypoint not in the flightplan - we don't sequence in this instance
 837                                 if(!_headingBugTo) {
 838                                         if(finalLeg) {
 839                                                 // Do nothing - not sure if Dto should switch off when arriving at the final waypoint of a flightplan
 840                                         } else if(finalDto) {
 841                                                 // Do nothing
 842                                         } else if(_activeWaypoint.appType == GPS_MAP) {
 843                                                 // Don't sequence beyond the missed approach point
 844                                                 cout << "ACTIVE WAYPOINT is MAP - not sequencing!!!!!\n";
 845                                         } else {
 846                                                 cout << "Sequencing...\n";
 847                                                 _fromWaypoint = _activeWaypoint;
 848                                                 _activeWaypoint = *_activeFP->waypoints[idx + 1];
 849                                                 _dto = false;
 850                                                 // TODO - course alteration message format is dependent on whether we are slaved HSI/CDI indicator or not.
 851                                                 // For now assume we are not.
 852                                                 string s;
 853                                                 if(fgGetBool("/instrumentation/nav[0]/slaved-to-gps")) {
 854                                                         // TODO - avoid the hardwiring on nav[0]
 855                                                         s = "Adj Nav Crs to ";
 856                                                 } else {
 857                                                         string s = "GPS Course is ";
 858                                                 }
 859                                                 double d = GetMagHeadingFromTo(_fromWaypoint.lat, _fromWaypoint.lon, _activeWaypoint.lat, _activeWaypoint.lon);
 860                                                 while(d < 0.0) d += 360.0;
 861                                                 while(d >= 360.0) d -= 360.0;
 862                                                 char buf[4];
 863                                                 snprintf(buf, 4, "%03i", (int)(d + 0.5));
 864                                                 s += buf;
 865                                                 _messageStack.push_back(s);
 866                                         }
 867                                         _waypointAlert = false;
 868                                 }
 869                         }
 870                 } else {
 871                         _eta = 0.0;
 872                 }
 873
 874                 /*
 875                 // First attempt at a sensible cross-track correction calculation
 876                 // Uh? - I think this is implemented further down the file!
 877                 if(_fromWaypoint != NULL) {
 878
 879                 } else {
 880                         _crosstrackDist = 0.0;
 881                 }
 882                 */
 883         }
 884 }
 885
 886 double DCLGPS::GetCDIDeflection() const {
 887         double xtd = CalcCrossTrackDeviation(); //nm
 888         return((xtd / _currentCdiScale) * 5.0 * 2.5 * -1.0);
 889 }
 890
 891 void DCLGPS::DtoInitiate(string s) {
 892         cout << "DtoInitiate, s = " << s << '\n';
 893         bool multi;
 894         const GPSWaypoint* wp = FindFirstById(s, multi, true);
 895         if(wp) {
 896                 cout << "Waypoint found, starting dto operation!\n";
 897                 _dto = true;
 898                 _activeWaypoint = *wp;
 899                 _fromWaypoint.lat = _gpsLat;
 900                 _fromWaypoint.lon = _gpsLon;
 901                 _fromWaypoint.type = GPS_WP_VIRT;
 902                 _fromWaypoint.id = "DTOWP";
 903         } else {
 904                 cout << "Waypoint not found, ignoring dto request\n";
 905                 // Should bring up the user waypoint page, but we're not implementing that yet.
 906                 _dto = false;   // TODO - implement this some day.
 907         }
 908 }
 909
 910 void DCLGPS::DtoCancel() {
 911         if(_dto) {
 912                 // i.e. don't bother reorientating if we're just cancelling a DTO button press
 913                 // without having previously initiated DTO.
 914                 OrientateToActiveFlightPlan();
 915         }
 916         _dto = false;
 917 }
 918
 919 void DCLGPS::Knob1Left1() {}
 920 void DCLGPS::Knob1Right1() {}
 921 void DCLGPS::Knob2Left1() {}
 922 void DCLGPS::Knob2Right1() {}
 923 void DCLGPS::CrsrPressed() { _activePage->CrsrPressed(); }
 924 void DCLGPS::EntPressed() { _activePage->EntPressed(); }
 925 void DCLGPS::ClrPressed() { _activePage->ClrPressed(); }
 926 void DCLGPS::DtoPressed() {}
 927 void DCLGPS::NrstPressed() {}
 928 void DCLGPS::AltPressed() {}
 929
 930 void DCLGPS::OBSPressed() {
 931         _obsMode = !_obsMode;
 932         if(_obsMode) {
 933                 if(!_activeWaypoint.id.empty()) {
 934                         _obsHeading = _dtkMag;
 935                 }
 936                 // TODO - the _fromWaypoint location will change as the OBS heading changes.
 937                 // Might need to store the OBS initiation position somewhere in case it is needed again.
 938                 SetOBSFromWaypoint();
 939         }
 940 }
 941
 942 // Set the _fromWaypoint position based on the active waypoint and OBS radial.
 943 void DCLGPS::SetOBSFromWaypoint() {
 944         if(!_obsMode) return;
 945         if(_activeWaypoint.id.empty()) return;
 946
 947         // TODO - base the 180 deg correction on the to/from flag.
 948         _fromWaypoint = GetPositionOnMagRadial(_activeWaypoint, 10, _obsHeading + 180.0);
 949         _fromWaypoint.id = "OBSWP";
 950 }
 951
 952 void DCLGPS::MsgPressed() {}
 953
 954 void DCLGPS::CDIFSDIncrease() {
 955         if(_currentCdiScaleIndex == 0) {
 956                 _currentCdiScaleIndex = _cdiScales.size() - 1;
 957         } else {
 958                 _currentCdiScaleIndex--;
 959         }
 960 }
 961
 962 void DCLGPS::CDIFSDDecrease() {
 963         _currentCdiScaleIndex++;
 964         if(_currentCdiScaleIndex == _cdiScales.size()) {
 965                 _currentCdiScaleIndex = 0;
 966         }
 967 }
 968
 969 void DCLGPS::DrawChar(char c, int field, int px, int py, bool bold) {
 970 }
 971
 972 void DCLGPS::DrawText(const string& s, int field, int px, int py, bool bold) {
 973 }
 974
 975 void DCLGPS::SetBaroUnits(int n, bool wrap) {
 976         if(n < 1) {
 977                 _baroUnits = (GPSPressureUnits)(wrap ? 3 : 1);
 978         } else if(n > 3) {
 979                 _baroUnits = (GPSPressureUnits)(wrap ? 1 : 3);
 980         } else {
 981                 _baroUnits = (GPSPressureUnits)n;
 982         }
 983 }
 984
 985 void DCLGPS::CreateDefaultFlightPlans() {}
 986
 987 // Get the time to the active waypoint in seconds.
 988 // Returns -1 if groundspeed < 30 kts
 989 double DCLGPS::GetTimeToActiveWaypoint() {
 990         if(_groundSpeed_kts < 30.0) {
 991                 return(-1.0);
 992         } else {
 993                 return(_eta);
 994         }
 995 }
 996
 997 // Get the time to the final waypoint in seconds.
 998 // Returns -1 if groundspeed < 30 kts
 999 double DCLGPS::GetETE() {
1000         if(_groundSpeed_kts < 30.0) {
1001                 return(-1.0);
1002         } else {
1003                 // TODO - handle OBS / DTO operation appropriately
1004                 if(_activeFP->waypoints.empty()) {
1005                         return(-1.0);
1006                 } else {
1007                         return(GetTimeToWaypoint(_activeFP->waypoints[_activeFP->waypoints.size() - 1]->id));
1008                 }
1009         }
1010 }
1011
1012 // Get the time to a given waypoint (spec'd by ID) in seconds.
1013 // returns -1 if groundspeed is less than 30kts.
1014 // If the waypoint is an unreached part of the active flight plan the time will be via each leg.
1015 // otherwise it will be a direct-to time.
1016 double DCLGPS::GetTimeToWaypoint(string id) {
1017         if(_groundSpeed_kts < 30.0) {
1018                 return(-1.0);
1019         }
1020
1021         double eta = 0.0;
1022         int n1 = GetActiveWaypointIndex();
1023         int n2 = GetWaypointIndex(id);
1024         if(n2 > n1) {
1025                 eta = _eta;
1026                 for(unsigned int i=n1+1; i<_activeFP->waypoints.size(); ++i) {
1027                         GPSWaypoint* wp1 = _activeFP->waypoints[i-1];
1028                         GPSWaypoint* wp2 = _activeFP->waypoints[i];
1029                         double distm = GetGreatCircleDistance(wp1->lat, wp1->lon, wp2->lat, wp2->lon) * SG_NM_TO_METER;
1030                         eta += (distm / _groundSpeed_ms);
1031                 }
1032                 return(eta);
1033         } else if(id == _activeWaypoint.id) {
1034                 return(_eta);
1035         } else {
1036                 bool multi;
1037                 const GPSWaypoint* wp = FindFirstById(id, multi, true);
1038                 if(wp == NULL) return(-1.0);
1039                 double distm = GetGreatCircleDistance(_gpsLat, _gpsLon, wp->lat, wp->lon);
1040                 return(distm / _groundSpeed_ms);
1041         }
1042         return(-1.0);   // Hopefully we never get here!
1043 }
1044
1045 // Returns magnetic great-circle heading
1046 // TODO - document units.
1047 float DCLGPS::GetHeadingToActiveWaypoint() {
1048         if(_activeWaypoint.id.empty()) {
1049                 return(-888);
1050         } else {
1051                 double h = GetMagHeadingFromTo(_gpsLat, _gpsLon, _activeWaypoint.lat, _activeWaypoint.lon);
1052                 while(h <= 0.0) h += 360.0;
1053                 while(h > 360.0) h -= 360.0;
1054                 return((float)h);
1055         }
1056 }
1057
1058 // Returns magnetic great-circle heading
1059 // TODO - what units?
1060 float DCLGPS::GetHeadingFromActiveWaypoint() {
1061         if(_activeWaypoint.id.empty()) {
1062                 return(-888);
1063         } else {
1064                 double h = GetMagHeadingFromTo(_activeWaypoint.lat, _activeWaypoint.lon, _gpsLat, _gpsLon);
1065                 while(h <= 0.0) h += 360.0;
1066                 while(h > 360.0) h -= 360.0;
1067                 return(h);
1068         }
1069 }
1070
1071 void DCLGPS::ClearFlightPlan(int n) {
1072         for(unsigned int i=0; i<_flightPlans[n]->waypoints.size(); ++i) {
1073                 delete _flightPlans[n]->waypoints[i];
1074         }
1075         _flightPlans[n]->waypoints.clear();
1076 }
1077
1078 void DCLGPS::ClearFlightPlan(GPSFlightPlan* fp) {
1079         for(unsigned int i=0; i<fp->waypoints.size(); ++i) {
1080                 delete fp->waypoints[i];
1081         }
1082         fp->waypoints.clear();
1083 }
1084
1085 int DCLGPS::GetActiveWaypointIndex() {
1086         for(unsigned int i=0; i<_flightPlans[0]->waypoints.size(); ++i) {
1087                 if(_flightPlans[0]->waypoints[i]->id == _activeWaypoint.id) return((int)i);
1088         }
1089         return(-1);
1090 }
1091
1092 int DCLGPS::GetWaypointIndex(string id) {
1093         for(unsigned int i=0; i<_flightPlans[0]->waypoints.size(); ++i) {
1094                 if(_flightPlans[0]->waypoints[i]->id == id) return((int)i);
1095         }
1096         return(-1);
1097 }
1098
1099 void DCLGPS::OrientateToFlightPlan(GPSFlightPlan* fp) {
1100         //cout << "Orientating...\n";
1101         //cout << "_lat = " << _lat << ", _lon = " << _lon << ", _gpsLat = " << _gpsLat << ", gpsLon = " << _gpsLon << '\n';
1102         if(fp->IsEmpty()) {
1103                 _activeWaypoint.id.clear();
1104                 _navFlagged = true;
1105         } else {
1106                 _navFlagged = false;
1107                 if(fp->waypoints.size() == 1) {
1108                         // TODO - may need to flag nav here if not dto or obs, or possibly handle it somewhere else.
1109                         _activeWaypoint = *fp->waypoints[0];
1110                         _fromWaypoint.id.clear();
1111                 } else {
1112                         // FIXME FIXME FIXME
1113                         _fromWaypoint = *fp->waypoints[0];
1114                         _activeWaypoint = *fp->waypoints[1];
1115                         double dmin = 1000000;  // nm!!
1116                         // For now we will simply start on the leg closest to our current position.
1117                         // It's possible that more fancy algorithms may take either heading or track
1118                         // into account when setting inital leg - I'm not sure.
1119                         // This method should handle most cases perfectly OK though.
1120                         for(unsigned int i = 1; i < fp->waypoints.size(); ++i) {
1121                                 //cout << "Pass " << i << ", dmin = " << dmin << ", leg is " << fp->waypoints[i-1]->id << " to " << fp->waypoints[i]->id << '\n';
1122                                 // First get the cross track correction.
1123                                 double d0 = fabs(CalcCrossTrackDeviation(*fp->waypoints[i-1], *fp->waypoints[i]));
1124                                 // That is the shortest distance away we could be though - check for
1125                                 // longer distances if we are 'off the end' of the leg.
1126                                 double ht1 = GetGreatCircleCourse(fp->waypoints[i-1]->lat, fp->waypoints[i-1]->lon,
1127                                                                   fp->waypoints[i]->lat, fp->waypoints[i]->lon)
1128                                                                                                   * SG_RADIANS_TO_DEGREES;
1129                                 // not simply the reverse of the above due to great circle navigation.
1130                                 double ht2 = GetGreatCircleCourse(fp->waypoints[i]->lat, fp->waypoints[i]->lon,
1131                                                                   fp->waypoints[i-1]->lat, fp->waypoints[i-1]->lon)
1132                                                                                                   * SG_RADIANS_TO_DEGREES;
1133                                 double hw1 = GetGreatCircleCourse(_gpsLat, _gpsLon,
1134                                                                   fp->waypoints[i]->lat, fp->waypoints[i]->lon)
1135                                                                                                   * SG_RADIANS_TO_DEGREES;
1136                                 double hw2 = GetGreatCircleCourse(_gpsLat, _gpsLon,
1137                                                                   fp->waypoints[i-1]->lat, fp->waypoints[i-1]->lon)
1138                                                                                                   * SG_RADIANS_TO_DEGREES;
1139                                 double h1 = ht1 - hw1;
1140                                 double h2 = ht2 - hw2;
1141                                 //cout << "d0, h1, h2 = " << d0 << ", " << h1 << ", " << h2 << '\n';
1142                                 //cout << "Normalizing...\n";
1143                                 SG_NORMALIZE_RANGE(h1, -180.0, 180.0);
1144                                 SG_NORMALIZE_RANGE(h2, -180.0, 180.0);
1145                                 //cout << "d0, h1, h2 = " << d0 << ", " << h1 << ", " << h2 << '\n';
1146                                 if(fabs(h1) > 90.0) {
1147                                         // We are past the end of the to waypoint
1148                                         double d = GetGreatCircleDistance(_gpsLat, _gpsLon, fp->waypoints[i]->lat, fp->waypoints[i]->lon);
1149                                         if(d > d0) d0 = d;
1150                                         //cout << "h1 triggered, d0 now = " << d0 << '\n';
1151                                 } else if(fabs(h2) > 90.0) {
1152                                         // We are past the end (not yet at!) the from waypoint
1153                                         double d = GetGreatCircleDistance(_gpsLat, _gpsLon, fp->waypoints[i-1]->lat, fp->waypoints[i-1]->lon);
1154                                         if(d > d0) d0 = d;
1155                                         //cout << "h2 triggered, d0 now = " << d0 << '\n';
1156                                 }
1157                                 if(d0 < dmin) {
1158                                         //cout << "THIS LEG NOW ACTIVE!\n";
1159                                         dmin = d0;
1160                                         _fromWaypoint = *fp->waypoints[i-1];
1161                                         _activeWaypoint = *fp->waypoints[i];
1162                                 }
1163                         }
1164                 }
1165         }
1166 }
1167
1168 void DCLGPS::OrientateToActiveFlightPlan() {
1169         OrientateToFlightPlan(_activeFP);
1170 }
1171
1172 /***************************************/
1173
1174 // Utility function - create a flightplan from a list of waypoint ids and types
1175 void DCLGPS::CreateFlightPlan(GPSFlightPlan* fp, vector<string> ids, vector<GPSWpType> wps) {
1176         if(fp == NULL) fp = new GPSFlightPlan;
1177         unsigned int i;
1178         if(!fp->waypoints.empty()) {
1179                 for(i=0; i<fp->waypoints.size(); ++i) {
1180                         delete fp->waypoints[i];
1181                 }
1182                 fp->waypoints.clear();
1183         }
1184         if(ids.size() != wps.size()) {
1185                 cout << "ID and Waypoint types list size mismatch in GPS::CreateFlightPlan - no flightplan created!\n";
1186                 return;
1187         }
1188         for(i=0; i<ids.size(); ++i) {
1189                 bool multi;
1190                 const FGAirport* ap;
1191                 FGNavRecord* np;
1192                 GPSWaypoint* wp = new GPSWaypoint;
1193                 wp->type = wps[i];
1194                 switch(wp->type) {
1195                 case GPS_WP_APT:
1196                         ap = FindFirstAptById(ids[i], multi, true);
1197                         if(ap == NULL) {
1198                                 // error
1199                                 delete wp;
1200                         } else {
1201                                 wp->lat = ap->getLatitude() * SG_DEGREES_TO_RADIANS;
1202                                 wp->lon = ap->getLongitude() * SG_DEGREES_TO_RADIANS;
1203                                 wp->id = ids[i];
1204                                 fp->waypoints.push_back(wp);
1205                         }
1206                         break;
1207                 case GPS_WP_VOR:
1208                         np = FindFirstVorById(ids[i], multi, true);
1209                         if(np == NULL) {
1210                                 // error
1211                                 delete wp;
1212                         } else {
1213                                 wp->lat = np->get_lat() * SG_DEGREES_TO_RADIANS;
1214                                 wp->lon = np->get_lon() * SG_DEGREES_TO_RADIANS;
1215                                 wp->id = ids[i];
1216                                 fp->waypoints.push_back(wp);
1217                         }
1218                         break;
1219                 case GPS_WP_NDB:
1220                         np = FindFirstNDBById(ids[i], multi, true);
1221                         if(np == NULL) {
1222                                 // error
1223                                 delete wp;
1224                         } else {
1225                                 wp->lat = np->get_lat() * SG_DEGREES_TO_RADIANS;
1226                                 wp->lon = np->get_lon() * SG_DEGREES_TO_RADIANS;
1227                                 wp->id = ids[i];
1228                                 fp->waypoints.push_back(wp);
1229                         }
1230                         break;
1231                 case GPS_WP_INT:
1232                         // TODO TODO
1233                         break;
1234                 case GPS_WP_USR:
1235                         // TODO
1236                         break;
1237                 }
1238         }
1239 }
1240
1241 /***************************************/
1242
1243 const GPSWaypoint* DCLGPS::ActualFindFirstById(string id, bool exact) {
1244     gps_waypoint_map_const_iterator itr;
1245     if(exact) {
1246         itr = _waypoints.find(id);
1247     } else {
1248         itr = _waypoints.lower_bound(id);
1249     }
1250     if(itr == _waypoints.end()) {
1251         return(NULL);
1252     } else {
1253                 // TODO - don't just return the first one - either return all or the nearest one.
1254         return((itr->second)[0]);
1255     }
1256 }
1257
1258 const GPSWaypoint* DCLGPS::FindFirstById(string id, bool &multi, bool exact) {
1259         multi = false;
1260         if(exact) return(ActualFindFirstById(id, exact));
1261
1262         // OK, that was the easy case, now the fuzzy case
1263         const GPSWaypoint* w1 = ActualFindFirstById(id);
1264         if(w1 == NULL) return(w1);
1265
1266         // The non-trivial code from here to the end of the function is all to deal with the fact that
1267         // the KLN89 alphabetical order (numbers AFTER letters) differs from ASCII order (numbers BEFORE letters).
1268         string id2 = id;
1269         //string id3 = id+'0';
1270         string id4 = id+'A';
1271         // Increment the last char to provide the boundary.  Note that 'Z' -> '[' but we also need to check '0' for all since GPS has numbers after letters
1272         //bool alfa = isalpha(id2[id2.size() - 1]);
1273         id2[id2.size() - 1] = id2[id2.size() - 1] + 1;
1274         const GPSWaypoint* w2 = ActualFindFirstById(id2);
1275         //FGAirport* a3 = globals->get_airports()->findFirstById(id3);
1276         const GPSWaypoint* w4 = ActualFindFirstById(id4);
1277         //cout << "Strings sent were " << id << ", " << id2 << " and " << id4 << '\n';
1278         //cout << "Airports returned were (a1, a2, a4): " << a1->getId() << ", " << a2->getId() << ", " << a4->getId() << '\n';
1279         //cout << "Pointers were " << a1 << ", " << a2 << ", " << a4 << '\n';
1280
1281         // TODO - the below handles the imediately following char OK
1282         // eg id = "KD" returns "KDAA" instead of "KD5"
1283         // but it doesn't handle numbers / letters further down the string,
1284         // eg - id = "I" returns "IA01" instead of "IAN"
1285         // We either need to provide a custom comparison operator, or recurse this function if !isalpha further down the string.
1286         // (Currenly fixed with recursion).
1287
1288         if(w4 != w2) { // A-Z match - preferred
1289                 //cout << "A-Z match!\n";
1290                 if(w4->id.size() - id.size() > 2) {
1291                         // Check for numbers further on
1292                         for(unsigned int i=id.size(); i<w4->id.size(); ++i) {
1293                                 if(!isalpha(w4->id[i])) {
1294                                         //cout << "SUBSTR is " << (a4->getId()).substr(0, i) << '\n';
1295                                         return(FindFirstById(w4->id.substr(0, i), multi, exact));
1296                                 }
1297                         }
1298                 }
1299                 return(w4);
1300         } else if(w1 != w2) {  // 0-9 match
1301                 //cout << "0-9 match!\n";
1302                 if(w1->id.size() - id.size() > 2) {
1303                         // Check for numbers further on
1304                         for(unsigned int i=id.size(); i<w1->id.size(); ++i) {
1305                                 if(!isalpha(w1->id[i])) {
1306                                         //cout << "SUBSTR2 is " << (a4->getId()).substr(0, i) << '\n';
1307                                         return(FindFirstById(w1->id.substr(0, i), multi, exact));
1308                                 }
1309                         }
1310                 }
1311                 return(w1);
1312         } else {  // No match
1313                 return(NULL);
1314         }
1315         return NULL;
1316 }
1317
1318 // Host specific lookup functions
1319 // TODO - add the ASCII / alphabetical stuff from the Atlas version
1320 FGNavRecord* DCLGPS::FindFirstVorById(string id, bool &multi, bool exact) {
1321         // NOTE - at the moment multi is never set.
1322         multi = false;
1323         //if(exact) return(_overlays->FindFirstVorById(id, exact));
1324
1325         nav_list_type nav = globals->get_navlist()->findFirstByIdent(id, FG_NAV_VOR, exact);
1326
1327         if(nav.size() > 1) multi = true;
1328         //return(nav.empty() ? NULL : *(nav.begin()));
1329
1330         // The above is sort of what we want - unfortunately we can't guarantee no NDB/ILS at the moment
1331         if(nav.empty()) return(NULL);
1332
1333         for(nav_list_iterator it = nav.begin(); it != nav.end(); ++it) {
1334                 if((*it)->get_type() == 3) return(*it);
1335         }
1336         return(NULL);   // Shouldn't get here!
1337 }
1338 #if 0
1339 Overlays::NAV* DCLGPS::FindFirstVorById(string id, bool &multi, bool exact) {
1340         // NOTE - at the moment multi is never set.
1341         multi = false;
1342         if(exact) return(_overlays->FindFirstVorById(id, exact));
1343
1344         // OK, that was the easy case, now the fuzzy case
1345         Overlays::NAV* n1 = _overlays->FindFirstVorById(id);
1346         if(n1 == NULL) return(n1);
1347
1348         string id2 = id;
1349         string id3 = id+'0';
1350         string id4 = id+'A';
1351         // Increment the last char to provide the boundary.  Note that 'Z' -> '[' but we also need to check '0' for all since GPS has numbers after letters
1352         bool alfa = isalpha(id2[id2.size() - 1]);
1353         id2[id2.size() - 1] = id2[id2.size() - 1] + 1;
1354         Overlays::NAV* n2 = _overlays->FindFirstVorById(id2);
1355         //Overlays::NAV* n3 = _overlays->FindFirstVorById(id3);
1356         //Overlays::NAV* n4 = _overlays->FindFirstVorById(id4);
1357         //cout << "Strings sent were " << id << ", " << id2 << ", " << id3 << ", " << id4 << '\n';
1358
1359
1360         if(alfa) {
1361                 if(n1 != n2) { // match
1362                         return(n1);
1363                 } else {
1364                         return(NULL);
1365                 }
1366         }
1367
1368         /*
1369         if(n1 != n2) {
1370                 // Something matches - the problem is the number/letter preference order is reversed between the GPS and the STL
1371                 if(n4 != n2) {
1372                         // There's a letter match - return that
1373                         return(n4);
1374                 } else {
1375                         // By definition we must have a number match
1376                         if(n3 == n2) cout << "HELP - LOGIC FLAW in find VOR!\n";
1377                         return(n3);
1378                 }
1379         } else {
1380                 // No match
1381                 return(NULL);
1382         }
1383         */
1384         return NULL;
1385 }
1386 #endif //0
1387
1388 // TODO - add the ASCII / alphabetical stuff from the Atlas version
1389 FGNavRecord* DCLGPS::FindFirstNDBById(string id, bool &multi, bool exact) {
1390         // NOTE - at the moment multi is never set.
1391         multi = false;
1392         //if(exact) return(_overlays->FindFirstVorById(id, exact));
1393
1394         nav_list_type nav = globals->get_navlist()->findFirstByIdent(id, FG_NAV_NDB, exact);
1395
1396         if(nav.size() > 1) multi = true;
1397         //return(nav.empty() ? NULL : *(nav.begin()));
1398
1399         // The above is sort of what we want - unfortunately we can't guarantee no NDB/ILS at the moment
1400         if(nav.empty()) return(NULL);
1401
1402         for(nav_list_iterator it = nav.begin(); it != nav.end(); ++it) {
1403                 if((*it)->get_type() == 2) return(*it);
1404         }
1405         return(NULL);   // Shouldn't get here!
1406 }
1407 #if 0
1408 Overlays::NAV* DCLGPS::FindFirstNDBById(string id, bool &multi, bool exact) {
1409         // NOTE - at the moment multi is never set.
1410         multi = false;
1411         if(exact) return(_overlays->FindFirstNDBById(id, exact));
1412
1413         // OK, that was the easy case, now the fuzzy case
1414         Overlays::NAV* n1 = _overlays->FindFirstNDBById(id);
1415         if(n1 == NULL) return(n1);
1416
1417         string id2 = id;
1418         string id3 = id+'0';
1419         string id4 = id+'A';
1420         // Increment the last char to provide the boundary.  Note that 'Z' -> '[' but we also need to check '0' for all since GPS has numbers after letters
1421         bool alfa = isalpha(id2[id2.size() - 1]);
1422         id2[id2.size() - 1] = id2[id2.size() - 1] + 1;
1423         Overlays::NAV* n2 = _overlays->FindFirstNDBById(id2);
1424         //Overlays::NAV* n3 = _overlays->FindFirstNDBById(id3);
1425         //Overlays::NAV* n4 = _overlays->FindFirstNDBById(id4);
1426         //cout << "Strings sent were " << id << ", " << id2 << ", " << id3 << ", " << id4 << '\n';
1427
1428
1429         if(alfa) {
1430                 if(n1 != n2) { // match
1431                         return(n1);
1432                 } else {
1433                         return(NULL);
1434                 }
1435         }
1436
1437         /*
1438         if(n1 != n2) {
1439                 // Something matches - the problem is the number/letter preference order is reversed between the GPS and the STL
1440                 if(n4 != n2) {
1441                         // There's a letter match - return that
1442                         return(n4);
1443                 } else {
1444                         // By definition we must have a number match
1445                         if(n3 == n2) cout << "HELP - LOGIC FLAW in find VOR!\n";
1446                         return(n3);
1447                 }
1448         } else {
1449                 // No match
1450                 return(NULL);
1451         }
1452         */
1453         return NULL;
1454 }
1455 #endif //0
1456
1457 // TODO - add the ASCII / alphabetical stuff from the Atlas version
1458 const FGFix* DCLGPS::FindFirstIntById(string id, bool &multi, bool exact) {
1459         // NOTE - at the moment multi is never set, and indeed can't be
1460         // since FG can only map one Fix per ID at the moment.
1461         multi = false;
1462         if(exact) return(globals->get_fixlist()->findFirstByIdent(id, exact));
1463
1464         const FGFix* f1 = globals->get_fixlist()->findFirstByIdent(id, exact);
1465         if(f1 == NULL) return(f1);
1466
1467         // The non-trivial code from here to the end of the function is all to deal with the fact that
1468         // the KLN89 alphabetical order (numbers AFTER letters) differs from ASCII order (numbers BEFORE letters).
1469         // It is copied from the airport version which is definately needed, but at present I'm not actually
1470         // sure if any fixes in FG or real-life have numbers in them!
1471         string id2 = id;
1472         //string id3 = id+'0';
1473         string id4 = id+'A';
1474         // Increment the last char to provide the boundary.  Note that 'Z' -> '[' but we also need to check '0' for all since GPS has numbers after letters
1475         //bool alfa = isalpha(id2[id2.size() - 1]);
1476         id2[id2.size() - 1] = id2[id2.size() - 1] + 1;
1477         const FGFix* f2 = globals->get_fixlist()->findFirstByIdent(id2);
1478         //const FGFix* a3 = globals->get_fixlist()->findFirstByIdent(id3);
1479         const FGFix* f4 = globals->get_fixlist()->findFirstByIdent(id4);
1480
1481         // TODO - the below handles the imediately following char OK
1482         // eg id = "KD" returns "KDAA" instead of "KD5"
1483         // but it doesn't handle numbers / letters further down the string,
1484         // eg - id = "I" returns "IA01" instead of "IAN"
1485         // We either need to provide a custom comparison operator, or recurse this function if !isalpha further down the string.
1486         // (Currenly fixed with recursion).
1487
1488         if(f4 != f2) { // A-Z match - preferred
1489                 //cout << "A-Z match!\n";
1490                 if(f4->get_ident().size() - id.size() > 2) {
1491                         // Check for numbers further on
1492                         for(unsigned int i=id.size(); i<f4->get_ident().size(); ++i) {
1493                                 if(!isalpha(f4->get_ident()[i])) {
1494                                         //cout << "SUBSTR is " << (a4->getId()).substr(0, i) << '\n';
1495                                         return(FindFirstIntById(f4->get_ident().substr(0, i), multi, exact));
1496                                 }
1497                         }
1498                 }
1499                 return(f4);
1500         } else if(f1 != f2) {  // 0-9 match
1501                 //cout << "0-9 match!\n";
1502                 if(f1->get_ident().size() - id.size() > 2) {
1503                         // Check for numbers further on
1504                         for(unsigned int i=id.size(); i<f1->get_ident().size(); ++i) {
1505                                 if(!isalpha(f1->get_ident()[i])) {
1506                                         //cout << "SUBSTR2 is " << (a4->getId()).substr(0, i) << '\n';
1507                                         return(FindFirstIntById(f1->get_ident().substr(0, i), multi, exact));
1508                                 }
1509                         }
1510                 }
1511                 return(f1);
1512         } else {  // No match
1513                 return(NULL);
1514         }
1515
1516         return NULL;    // Don't think we can ever get here.
1517 }
1518
1519 const FGAirport* DCLGPS::FindFirstAptById(string id, bool &multi, bool exact) {
1520         // NOTE - at the moment multi is never set.
1521         //cout << "FindFirstAptById, id = " << id << '\n';
1522         multi = false;
1523         if(exact) return(globals->get_airports()->findFirstById(id, exact));
1524
1525         // OK, that was the easy case, now the fuzzy case
1526         const FGAirport* a1 = globals->get_airports()->findFirstById(id);
1527         if(a1 == NULL) return(a1);
1528
1529         // The non-trivial code from here to the end of the function is all to deal with the fact that
1530         // the KLN89 alphabetical order (numbers AFTER letters) differs from ASCII order (numbers BEFORE letters).
1531         string id2 = id;
1532         //string id3 = id+'0';
1533         string id4 = id+'A';
1534         // Increment the last char to provide the boundary.  Note that 'Z' -> '[' but we also need to check '0' for all since GPS has numbers after letters
1535         //bool alfa = isalpha(id2[id2.size() - 1]);
1536         id2[id2.size() - 1] = id2[id2.size() - 1] + 1;
1537         const FGAirport* a2 = globals->get_airports()->findFirstById(id2);
1538         //FGAirport* a3 = globals->get_airports()->findFirstById(id3);
1539         const FGAirport* a4 = globals->get_airports()->findFirstById(id4);
1540         //cout << "Strings sent were " << id << ", " << id2 << " and " << id4 << '\n';
1541         //cout << "Airports returned were (a1, a2, a4): " << a1->getId() << ", " << a2->getId() << ", " << a4->getId() << '\n';
1542         //cout << "Pointers were " << a1 << ", " << a2 << ", " << a4 << '\n';
1543
1544         // TODO - the below handles the imediately following char OK
1545         // eg id = "KD" returns "KDAA" instead of "KD5"
1546         // but it doesn't handle numbers / letters further down the string,
1547         // eg - id = "I" returns "IA01" instead of "IAN"
1548         // We either need to provide a custom comparison operator, or recurse this function if !isalpha further down the string.
1549         // (Currenly fixed with recursion).
1550
1551         if(a4 != a2) { // A-Z match - preferred
1552                 //cout << "A-Z match!\n";
1553                 if(a4->getId().size() - id.size() > 2) {
1554                         // Check for numbers further on
1555                         for(unsigned int i=id.size(); i<a4->getId().size(); ++i) {
1556                                 if(!isalpha(a4->getId()[i])) {
1557                                         //cout << "SUBSTR is " << (a4->getId()).substr(0, i) << '\n';
1558                                         return(FindFirstAptById(a4->getId().substr(0, i), multi, exact));
1559                                 }
1560                         }
1561                 }
1562                 return(a4);
1563         } else if(a1 != a2) {  // 0-9 match
1564                 //cout << "0-9 match!\n";
1565                 if(a1->getId().size() - id.size() > 2) {
1566                         // Check for numbers further on
1567                         for(unsigned int i=id.size(); i<a1->getId().size(); ++i) {
1568                                 if(!isalpha(a1->getId()[i])) {
1569                                         //cout << "SUBSTR2 is " << (a4->getId()).substr(0, i) << '\n';
1570                                         return(FindFirstAptById(a1->getId().substr(0, i), multi, exact));
1571                                 }
1572                         }
1573                 }
1574                 return(a1);
1575         } else {  // No match
1576                 return(NULL);
1577         }
1578
1579         return NULL;
1580 }
1581
1582 FGNavRecord* DCLGPS::FindClosestVor(double lat_rad, double lon_rad) {
1583         return(globals->get_navlist()->findClosest(lon_rad, lat_rad, 0.0, FG_NAV_VOR));
1584 }
1585
1586 //----------------------------------------------------------------------------------------------------------
1587
1588 // Takes lat and lon in RADIANS!!!!!!!
1589 double DCLGPS::GetMagHeadingFromTo(double latA, double lonA, double latB, double lonB) {
1590         double h = GetGreatCircleCourse(latA, lonA, latB, lonB);
1591         h *= SG_RADIANS_TO_DEGREES;
1592         // TODO - use the real altitude below instead of 0.0!
1593         //cout << "MagVar = " << sgGetMagVar(_gpsLon, _gpsLat, 0.0, _time->getJD()) * SG_RADIANS_TO_DEGREES << '\n';
1594         h -= sgGetMagVar(_gpsLon, _gpsLat, 0.0, _time->getJD()) * SG_RADIANS_TO_DEGREES;
1595         while(h >= 360.0) h -= 360.0;
1596         while(h < 0.0) h += 360.0;
1597         return(h);
1598 }
1599
1600 // ---------------- Great Circle formulae from "The Aviation Formulary" -------------
1601 // Note that all of these assume that the world is spherical.
1602
1603 double Rad2Nm(double theta) {
1604         return(((180.0*60.0)/SG_PI)*theta);
1605 }
1606
1607 double Nm2Rad(double d) {
1608         return((SG_PI/(180.0*60.0))*d);
1609 }
1610
1611 /* QUOTE:
1612
1613 The great circle distance d between two points with coordinates {lat1,lon1} and {lat2,lon2} is given by:
1614
1615 d=acos(sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(lon1-lon2))
1616
1617 A mathematically equivalent formula, which is less subject to rounding error for short distances is:
1618
1619 d=2*asin(sqrt((sin((lat1-lat2)/2))^2 +
1620                  cos(lat1)*cos(lat2)*(sin((lon1-lon2)/2))^2))
1621
1622 */
1623
1624 // Returns distance in nm, takes lat & lon in RADIANS
1625 double DCLGPS::GetGreatCircleDistance(double lat1, double lon1, double lat2, double lon2) const {
1626         double d = 2.0 * asin(sqrt(((sin((lat1-lat2)/2.0))*(sin((lat1-lat2)/2.0))) +
1627                    cos(lat1)*cos(lat2)*(sin((lon1-lon2)/2.0))*(sin((lon1-lon2)/2.0))));
1628         return(Rad2Nm(d));
1629 }
1630
1631 // fmod dosen't do what we want :-(
1632 static double mod(double d1, double d2) {
1633         return(d1 - d2*floor(d1/d2));
1634 }
1635
1636 // Returns great circle course from point 1 to point 2
1637 // Input and output in RADIANS.
1638 double DCLGPS::GetGreatCircleCourse (double lat1, double lon1, double lat2, double lon2) const {
1639         //double h = 0.0;
1640         /*
1641         // Special case the poles
1642         if(cos(lat1) < SG_EPSILON) {
1643                 if(lat1 > 0) {
1644                         // Starting from North Pole
1645                         h = SG_PI;
1646                 } else {
1647                         // Starting from South Pole
1648                         h = 2.0 * SG_PI;
1649                 }
1650         } else {
1651                 // Urgh - the formula below is for negative lon +ve !!!???
1652                 double d = GetGreatCircleDistance(lat1, lon1, lat2, lon2);
1653                 cout << "d = " << d;
1654                 d = Nm2Rad(d);
1655                 //cout << ", d_theta = " << d;
1656                 //cout << ", and d = " << Rad2Nm(d) << ' ';
1657                 if(sin(lon2 - lon1) < 0) {
1658                         cout << " A ";
1659                         h = acos((sin(lat2)-sin(lat1)*cos(d))/(sin(d)*cos(lat1)));
1660                 } else {
1661                         cout << " B ";
1662                         h = 2.0 * SG_PI - acos((sin(lat2)-sin(lat1)*cos(d))/(sin(d)*cos(lat1)));
1663                 }
1664         }
1665         cout << h * SG_RADIANS_TO_DEGREES << '\n';
1666         */
1667
1668         return( mod(atan2(sin(lon2-lon1)*cos(lat2),
1669             cos(lat1)*sin(lat2)-sin(lat1)*cos(lat2)*cos(lon2-lon1)),
1670             2.0*SG_PI) );
1671 }
1672
1673 // Return a position on a radial from wp1 given distance d (nm) and magnetic heading h (degrees)
1674 // Note that d should be less that 1/4 Earth diameter!
1675 GPSWaypoint DCLGPS::GetPositionOnMagRadial(const GPSWaypoint& wp1, double d, double h) {
1676         h += sgGetMagVar(wp1.lon, wp1.lat, 0.0, _time->getJD()) * SG_RADIANS_TO_DEGREES;
1677         return(GetPositionOnRadial(wp1, d, h));
1678 }
1679
1680 // Return a position on a radial from wp1 given distance d (nm) and TRUE heading h (degrees)
1681 // Note that d should be less that 1/4 Earth diameter!
1682 GPSWaypoint DCLGPS::GetPositionOnRadial(const GPSWaypoint& wp1, double d, double h) {
1683         while(h < 0.0) h += 360.0;
1684         while(h > 360.0) h -= 360.0;
1685
1686         h *= SG_DEGREES_TO_RADIANS;
1687         d *= (SG_PI / (180.0 * 60.0));
1688
1689         double lat=asin(sin(wp1.lat)*cos(d)+cos(wp1.lat)*sin(d)*cos(h));
1690         double lon;
1691         if(cos(lat)==0) {
1692                 lon=wp1.lon;      // endpoint a pole
1693         } else {
1694                 lon=mod(wp1.lon+asin(sin(h)*sin(d)/cos(lat))+SG_PI,2*SG_PI)-SG_PI;
1695         }
1696
1697         GPSWaypoint wp;
1698         wp.lat = lat;
1699         wp.lon = lon;
1700         wp.type = GPS_WP_VIRT;
1701         return(wp);
1702 }
1703
1704 // Returns cross-track deviation in Nm.
1705 double DCLGPS::CalcCrossTrackDeviation() const {
1706         return(CalcCrossTrackDeviation(_fromWaypoint, _activeWaypoint));
1707 }
1708
1709 // Returns cross-track deviation of the current position between two arbitary waypoints in nm.
1710 double DCLGPS::CalcCrossTrackDeviation(const GPSWaypoint& wp1, const GPSWaypoint& wp2) const {
1711         //if(wp1 == NULL || wp2 == NULL) return(0.0);
1712         if(wp1.id.empty() || wp2.id.empty()) return(0.0);
1713         double xtd = asin(sin(Nm2Rad(GetGreatCircleDistance(wp1.lat, wp1.lon, _gpsLat, _gpsLon)))
1714                           * sin(GetGreatCircleCourse(wp1.lat, wp1.lon, _gpsLat, _gpsLon) - GetGreatCircleCourse(wp1.lat, wp1.lon, wp2.lat, wp2.lon)));
1715         return(Rad2Nm(xtd));
1716 }