src/ATC/approach.cxx

   1 // FGApproach - a class to provide approach control at larger airports.
   2 //
   3 // Written by Alexander Kappes, started March 2002.
   4 //
   5 // Copyright (C) 2002  Alexander Kappes
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 #include "approach.hxx"
  22 #include "transmission.hxx"
  23 #include "transmissionlist.hxx"
  24 #include "ATCdisplay.hxx"
  25 #include "ATCDialog.hxx"
  26
  27 #include <Airports/runways.hxx>
  28 #include <simgear/math/polar3d.hxx>
  29 #include <simgear/misc/sg_path.hxx>
  30
  31 #ifdef FG_WEATHERCM
  32 # include <WeatherCM/FGLocalWeatherDatabase.h>
  33 #else
  34 # include <Environment/environment_mgr.hxx>
  35 # include <Environment/environment.hxx>
  36 #endif
  37
  38
  39 #include <GUI/gui.h>
  40
  41 //Constructor
  42 FGApproach::FGApproach(){
  43   comm1_node = fgGetNode("/radios/comm[0]/frequencies/selected-mhz", true);
  44   comm2_node = fgGetNode("/radios/comm[1]/frequencies/selected-mhz", true);
  45
  46   _type = APPROACH;
  47
  48   num_planes = 0;
  49   lon_node   = fgGetNode("/position/longitude-deg", true);
  50   lat_node   = fgGetNode("/position/latitude-deg", true);
  51   elev_node  = fgGetNode("/position/altitude-ft", true);
  52   hdg_node   = fgGetNode("/orientation/heading-deg", true);
  53   speed_node = fgGetNode("/velocities/airspeed-kt", true);
  54   etime_node = fgGetNode("/sim/time/elapsed-ms", true);
  55
  56   first = true;
  57   active_runway = "";
  58   int i;
  59   for ( i=0; i<max_planes; i++) {
  60     planes[i].contact   = 0;
  61     planes[i].wpn       = 0;
  62     planes[i].dnwp      = -999.;
  63     planes[i].on_crs    = true;
  64     planes[i].turn_rate = 10.0;
  65     planes[i].desc_rate = 1000.0;
  66     planes[i].clmb_rate = 500.0;
  67     planes[i].tlm       = 0.0;
  68     planes[i].lmc.c1    = 0;
  69     planes[i].lmc.c2    = 0;
  70     planes[i].lmc.c3    = -1;
  71     planes[i].wp_change = false;
  72   }
  73 }
  74
  75 //Destructor
  76 FGApproach::~FGApproach(){
  77 }
  78
  79 void FGApproach::Init() {
  80 }
  81
  82
  83
  84 // ============================================================================
  85 // the main update function
  86 // ============================================================================
  87 void FGApproach::Update(double dt) {
  88
  89         const int max_trans = 20;
  90         FGTransmission tmissions[max_trans];
  91         int    wpn;
  92         atc_type station = APPROACH;
  93         TransCode code;
  94         TransPar TPar;
  95         int    i,j;
  96         //double course, d,
  97         double adif, datp;
  98         //char   buf[10];
  99         string message;
 100         //static string atcmsg1[10];
 101         //static string atcmsg2[10];
 102         string mentry;
 103         string transm;
 104         TransPar tpars;
 105         //static bool TransDisplayed = false;
 106
 107         update_plane_dat();
 108         if ( active_runway == "" ) get_active_runway();
 109
 110         double comm1_freq = comm1_node->getDoubleValue();
 111
 112         //bool DisplayTransmissions = true;
 113
 114         for (i=0; i<num_planes; i++) {
 115                 if ( planes[i].ident == "Player") {
 116                         station = APPROACH;
 117                         tpars.station = name;
 118                         tpars.callsign = "Player";
 119                         tpars.airport = ident;
 120
 121                         //cout << "ident = " << ident << " name = " << name << '\n';
 122
 123                         int num_trans = 0;
 124                         // is the frequency of the station tuned in?
 125                         if ( freq == (int)(comm1_freq*100.0 + 0.5) ) {
 126                                 current_transmissionlist->query_station( station, tmissions, max_trans, num_trans );
 127                                 // loop over all transmissions for station
 128                                 for ( j=0; j<=num_trans-1; j++ ) {
 129                                         code = tmissions[j].get_code();
 130                                         //cout << "code is " << code.c1 << "  " << code.c2 << "  " << code.c3 << '\n';
 131                                         // select proper transmissions
 132                                         if(code.c3 != 2) {    // DCL - hack to prevent request crossing airspace being displayed since this isn't implemented yet.
 133                                             if ( ( code.c2 == -1 && planes[i].lmc.c3 == 0 ) ||
 134                                                     ( code.c1 == 0  && code.c2 == planes[i].lmc.c2 ) ) {
 135                                                     mentry = current_transmissionlist->gen_text(station, code, tpars, false);
 136                                                     transm = current_transmissionlist->gen_text(station, code, tpars, true);
 137                                                     // is the transmission already registered?
 138                                                     if (!current_atcdialog->trans_reg( ident, transm, APPROACH )) {
 139                                                             current_atcdialog->add_entry( ident, transm, mentry, APPROACH, 0 );
 140                                                     }
 141                                             }
 142                                         }
 143                                 }
 144                         }
 145                 }
 146         }
 147
 148         for ( i=0; i<num_planes; i++ ) {
 149                 //cout << "TPar.airport = " << TPar.airport << " TPar.station = " << TPar.station << " TPar.callsign = " << TPar.callsign << '\n';
 150                 //if ( planes[i].ident == TPar.callsign && name == TPar.airport && TPar.station == "approach" ) {
 151                         //if ( TPar.request && TPar.intention == "landing" && ident == TPar.intid) {
 152                         if(planes[i].ident == "Player" && fgGetBool("/sim/atc/opt0")) {
 153                                 //cout << "Landing requested\n";
 154                                 fgSetBool("/sim/atc/opt0", false);
 155                                 planes[i].wpn = 0;
 156                                 // ===========================
 157                                 // === calculate waypoints ===
 158                                 // ===========================
 159                                 calc_wp( i );
 160                                 update_param( i );
 161                                 wpn = planes[i].wpn-1;
 162                                 planes[i].aalt = planes[i].wpts[wpn-1][2];
 163                                 planes[i].ahdg = planes[i].wpts[wpn][4];
 164
 165                                 // generate the message
 166                                 code.c1 = 1;
 167                                 code.c2 = 1;
 168                                 code.c3 = 0;
 169                                 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
 170                                 tpars.station = name;
 171                                 tpars.callsign = "Player";
 172                                 if ( adif < 0 ) tpars.tdir = 1;
 173                                 else            tpars.tdir = 2;
 174                                 tpars.heading = planes[i].ahdg;
 175                                 if      (planes[i].alt-planes[i].aalt > 100.0)  tpars.VDir = 1;
 176                                 else if (planes[i].alt-planes[i].aalt < -100.0) tpars.VDir = 3;
 177                                 else tpars.VDir = 2;
 178                                 tpars.alt = planes[i].aalt;
 179                                 message = current_transmissionlist->gen_text(station, code, tpars, true );
 180                                 //cout << message << '\n';
 181                                 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
 182                                 planes[i].lmc = code;
 183                                 planes[i].tlm = etime_node->getDoubleValue();
 184                                 planes[i].on_crs = true;
 185                                 planes[i].contact = 1;
 186                         }
 187                 //}
 188
 189                 //if(1) {
 190                 if ( planes[i].contact == 1 ) {
 191                         // =========================
 192                         // === update parameters ===
 193                         // =========================
 194                         update_param( i );
 195                         //cout << planes[i].brg << " " << planes[i].dist << " " << planes[i].wpts[wpn+1][0]
 196                         //<< " " << planes[i].wpts[wpn+1][1] << " " << planes[i].wpts[wpn+1][4]
 197                         //cout << wpn << " distance to current course = " << planes[i].dcc << endl;
 198                         //cout << etime_node->getDoubleValue() << endl;
 199
 200                         // =========================
 201                         // === reached waypoint? ===
 202                         // =========================
 203                         wpn = planes[i].wpn-2;
 204                         adif = angle_diff_deg( planes[i].hdg, planes[i].wpts[wpn][4] )
 205                         * SGD_DEGREES_TO_RADIANS;
 206                         datp = 2*sin(fabs(adif)/2.0)*sin(fabs(adif)/2.0) *
 207                                planes[i].spd/3600. * planes[i].turn_rate +
 208                                planes[i].spd/3600. * 3.0;
 209                         //cout << adif/SGD_DEGREES_TO_RADIANS << " "
 210                         //     << datp << " " << planes[i].dnc << " " << planes[i].dcc <<endl;
 211                         if ( fabs(planes[i].dnc) < datp ) {
 212                         //if ( fabs(planes[i].dnc) < 0.3 && planes[i].dnwp < 1.0 ) {
 213                                 //cout << "Reached next waypoint!\n";
 214                                 planes[i].wpn -= 1;
 215                                 wpn = planes[i].wpn-1;
 216                                 planes[i].ahdg = planes[i].wpts[wpn][4];
 217                                 planes[i].aalt = planes[i].wpts[wpn-1][2];
 218                                 planes[i].wp_change = true;
 219
 220                                 // generate the message
 221                                 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
 222                                 tpars.station = name;
 223                                 tpars.callsign = "Player";
 224                                 if ( adif < 0 ) tpars.tdir = 1;
 225                                 else            tpars.tdir = 2;
 226                                 tpars.heading = planes[i].ahdg;
 227
 228                                 if ( wpn-1 != 0) {
 229                                         code.c1 = 1;
 230                                         code.c2 = 1;
 231                                         code.c3 = 0;
 232                                         if      (planes[i].alt-planes[i].aalt > 100.0)  tpars.VDir = 1;
 233                                         else if (planes[i].alt-planes[i].aalt < -100.0) tpars.VDir = 3;
 234                                         else tpars.VDir = 2;
 235                                         tpars.alt = planes[i].aalt;
 236                                         message = current_transmissionlist->gen_text(station, code, tpars, true );
 237                                         //cout << "Approach transmitting...\n";
 238                                         //cout << message << endl;
 239                                         globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
 240
 241                                 }
 242                                 else {
 243                                         code.c1 = 1;
 244                                         code.c2 = 3;
 245                                         code.c3 = 0;
 246                                         tpars.runway = active_runway;
 247                                         message = current_transmissionlist->gen_text(station, code, tpars, true);
 248                                         //cout << "Approach transmitting 2 ...\n";
 249                                         //cout << message << endl;
 250                                         globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
 251                                 }
 252                                 planes[i].lmc = code;
 253                                 planes[i].tlm = etime_node->getDoubleValue();
 254                                 planes[i].on_crs = true;
 255
 256                                 update_param( i );
 257                         }
 258
 259                         // =========================
 260                         // === come off course ? ===
 261                         // =========================
 262                         if ( fabs(planes[i].dcc) > 1.0 &&
 263                            ( !planes[i].wp_change || etime_node->getDoubleValue() - planes[i].tlm > tbm ) ) {
 264                                 //cout << "Off course!\n";
 265                                 if ( planes[i].on_crs ) {
 266                                         if ( planes[i].dcc < 0) {
 267                                                 planes[i].ahdg += 30.0;
 268                                         }
 269                                         else {
 270                                                 planes[i].ahdg -= 30.0;
 271                                         }
 272                                         if (planes[i].ahdg > 360.0) planes[i].ahdg -= 360.0;
 273                                         else if (planes[i].ahdg < 0.0) planes[i].ahdg += 360.0;
 274                                 }
 275                                 //cout << planes[i].on_crs << " "
 276                                 //     << angle_diff_deg( planes[i].hdg, planes[i].ahdg) << " "
 277                                 //     << etime_node->getDoubleValue() << " "
 278                                 //     << planes[i].tlm << endl;
 279                                 // generate the message
 280                                 if ( planes[i].on_crs ||
 281                                    ( fabs(angle_diff_deg( planes[i].hdg, planes[i].ahdg )) >  30.0  &&
 282                                     etime_node->getDoubleValue() - planes[i].tlm > tbm) ) {
 283                                         // generate the message
 284                                         code.c1 = 1;
 285                                         code.c2 = 4;
 286                                         code.c3 = 0;
 287                                         adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
 288                                         tpars.station = name;
 289                                         tpars.callsign = "Player";
 290                                         tpars.miles   = fabs(planes[i].dcc);
 291                                         if ( adif < 0 ) tpars.tdir = 1;
 292                                         else            tpars.tdir = 2;
 293                                         tpars.heading = planes[i].ahdg;
 294                                         message = current_transmissionlist->gen_text(station, code, tpars, true);
 295                                         //cout << "Approach transmitting 3 ...\n";
 296                                         //cout << message << '\n';
 297                                         globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
 298                                         planes[i].lmc = code;
 299                                         planes[i].tlm = etime_node->getDoubleValue();
 300                                 }
 301
 302                                 planes[i].on_crs = false;
 303                         }
 304                         else if ( !planes[i].on_crs ) {
 305                                 //cout << "Off course 2!\n";
 306                                 wpn = planes[i].wpn-1;
 307                                 adif = angle_diff_deg( planes[i].hdg, planes[i].wpts[wpn][4] )
 308                                        * SGD_DEGREES_TO_RADIANS;
 309                                 datp = 2*sin(fabs(adif)/2.0)*sin(fabs(adif)/2.0) *
 310                                 planes[i].spd/3600. * planes[i].turn_rate +
 311                                 planes[i].spd/3600. * 3.0;
 312                                 if ( fabs(planes[i].dcc) < datp ) {
 313                                         planes[i].ahdg = fabs(planes[i].wpts[wpn][4]);
 314
 315                                         // generate the message
 316                                         code.c1 = 1;
 317                                         code.c2 = 2;
 318                                         code.c3 = 0;
 319                                         tpars.station = name;
 320                                         tpars.callsign = "Player";
 321                                         if ( adif < 0 ) tpars.tdir = 1;
 322                                         else            tpars.tdir = 2;
 323                                         tpars.heading = planes[i].ahdg;
 324                                         message = current_transmissionlist->gen_text(station, code, tpars, true);
 325                                         //cout << "Approach transmitting 4 ...\n";
 326                                         //cout << message << '\n';
 327                                         globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
 328                                         planes[i].lmc = code;
 329                                         planes[i].tlm = etime_node->getDoubleValue();
 330
 331                                         planes[i].on_crs = true;
 332                                 }
 333                         }
 334                         else if ( planes[i].wp_change  ) {
 335                                 planes[i].wp_change = false;
 336                         }
 337
 338                         // ===================================================================
 339                         // === Less than two minutes away from touchdown? -> Contact Tower ===
 340                         // ===================================================================
 341                         if ( planes[i].wpn == 2 && planes[i].dnwp < planes[i].spd/60.*2.0 ) {
 342
 343                                 double freq = 121.95;   // Hardwired - FIXME
 344                                 // generate message
 345                                 code.c1 = 1;
 346                                 code.c2 = 5;
 347                                 code.c3 = 0;
 348                                 tpars.station = name;
 349                                 tpars.callsign = "Player";
 350                                 tpars.freq    = freq;
 351                                 message = current_transmissionlist->gen_text(station, code, tpars, true);
 352                                 //cout << "Approach transmitting 5 ...\n";
 353                                 //cout << message << '\n';
 354                                 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
 355                                 planes[i].lmc = code;
 356                                 planes[i].tlm = etime_node->getDoubleValue();
 357
 358                                 planes[i].contact = 2;
 359                         }
 360                 }
 361         }
 362 }
 363
 364
 365 // ============================================================================
 366 // update course parameters
 367 // ============================================================================
 368 void FGApproach::update_param( const int &i ) {
 369
 370   double course, d;
 371
 372   int wpn = planes[i].wpn-1;            // this is the current waypoint
 373
 374   planes[i].dcc  = calc_psl_dist(planes[i].brg, planes[i].dist,
 375                                  planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
 376                                  planes[i].wpts[wpn][4]);
 377   planes[i].dnc  = calc_psl_dist(planes[i].brg, planes[i].dist,
 378                                  planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 379                                  planes[i].wpts[wpn-1][4]);
 380   calc_hd_course_dist(planes[i].brg, planes[i].dist,
 381                       planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 382                       &course, &d);
 383   planes[i].dnwp = d;
 384
 385 }
 386
 387 // ============================================================================
 388 // smallest difference between two angles in degree
 389 // difference is negative if a1 > a2 and positive if a2 > a1
 390 // ===========================================================================
 391 double FGApproach::angle_diff_deg( const double &a1, const double &a2) {
 392
 393   double a3 = a2 - a1;
 394   if (a3 < 180.0) a3 += 360.0;
 395   if (a3 > 180.0) a3 -= 360.0;
 396
 397   return a3;
 398 }
 399
 400 // ============================================================================
 401 // calculate waypoints
 402 // ============================================================================
 403 void FGApproach::calc_wp( const int &i ) {
 404
 405         int j;
 406         double course, d, cd, a1;
 407
 408         int wpn = planes[i].wpn;
 409         // waypoint 0: Threshold of active runway
 410         calc_gc_course_dist(Point3D(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0.0),
 411                             Point3D(active_rw_lon*SGD_DEGREES_TO_RADIANS,active_rw_lat*SGD_DEGREES_TO_RADIANS, 0.0 ),
 412                             &course, &d);
 413         double d1 = active_rw_hdg+180.0;
 414         if ( d1 > 360.0 ) d1 -=360.0;
 415         calc_cd_head_dist(360.0-course*SGD_RADIANS_TO_DEGREES, d/SG_NM_TO_METER,
 416                           d1, active_rw_len/SG_NM_TO_METER/2.0,
 417                           &planes[i].wpts[wpn][0], &planes[i].wpts[wpn][1]);
 418         planes[i].wpts[wpn][2] = elev;
 419         planes[i].wpts[wpn][4] = 0.0;
 420         planes[i].wpts[wpn][5] = 0.0;
 421         wpn += 1;
 422
 423         // ======================
 424         // horizontal navigation
 425         // ======================
 426         // waypoint 1: point for turning onto final
 427         calc_cd_head_dist(planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1], d1, lfl,
 428                           &planes[i].wpts[wpn][0], &planes[i].wpts[wpn][1]);
 429         calc_hd_course_dist(planes[i].wpts[wpn][0],   planes[i].wpts[wpn][1],
 430                             planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 431                             &course, &d);
 432         planes[i].wpts[wpn][4] = course;
 433         planes[i].wpts[wpn][5] = d;
 434         wpn += 1;
 435
 436         // calculate course and distance from plane position to waypoint 1
 437         calc_hd_course_dist(planes[i].brg, planes[i].dist, planes[i].wpts[1][0],
 438                             planes[i].wpts[1][1], &course, &d);
 439         // check if airport is not between plane and waypoint 1 and
 440         // DCA to airport on course to waypoint 1 is larger than 10 miles
 441         double zero = 0.0;
 442         if ( fabs(angle_diff_deg( planes[i].wpts[1][0], planes[i].brg  )) < 90.0 ||
 443                 calc_psl_dist( zero, zero, planes[i].brg, planes[i].dist, course ) > 10.0 ) {
 444                 // check if turning angle at waypoint 1 would be > max_ta
 445                 if ( fabs(angle_diff_deg( planes[i].wpts[1][4], course )) > max_ta ) {
 446                         cd = calc_psl_dist(planes[i].brg, planes[i].dist,
 447                              planes[i].wpts[1][0], planes[i].wpts[1][1],
 448                              planes[i].wpts[1][4]);
 449                         a1 = atan2(cd,planes[i].wpts[1][1]);
 450                         planes[i].wpts[wpn][0] = planes[i].wpts[1][0] - a1/SGD_DEGREES_TO_RADIANS;
 451                         if ( planes[i].wpts[wpn][0] < 0.0)   planes[i].wpts[wpn][0] += 360.0;
 452                         if ( planes[i].wpts[wpn][0] > 360.0) planes[i].wpts[wpn][0] -= 360.0;
 453                         planes[i].wpts[wpn][1] = fabs(cd) / sin(fabs(a1));
 454                         calc_hd_course_dist(planes[i].wpts[wpn][0],   planes[i].wpts[wpn][1],
 455                                             planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 456                                             &course, &d);
 457                         planes[i].wpts[wpn][4] = course;
 458                         planes[i].wpts[wpn][5] = d;
 459                         wpn += 1;
 460
 461                         calc_hd_course_dist(planes[i].brg, planes[i].dist, planes[i].wpts[wpn-1][0],
 462                                             planes[i].wpts[wpn-1][1], &course, &d);
 463                 }
 464         } else {
 465                 double leg = 10.0;
 466                 a1 = atan2(planes[i].wpts[1][1], leg );
 467
 468                 if ( angle_diff_deg(planes[i].brg,planes[i].wpts[1][0]) < 0 )
 469                         planes[i].wpts[wpn][0] = planes[i].wpts[1][0] + a1/SGD_DEGREES_TO_RADIANS;
 470                 else planes[i].wpts[wpn][0] = planes[i].wpts[1][0] - a1/SGD_DEGREES_TO_RADIANS;
 471
 472                 planes[i].wpts[wpn][1] = sqrt( planes[i].wpts[1][1]*planes[i].wpts[1][1] + leg*leg );
 473                 calc_hd_course_dist(planes[i].wpts[wpn][0],   planes[i].wpts[wpn][1],
 474                                     planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 475                                     &course, &d);
 476                 planes[i].wpts[wpn][4] = course;
 477                 planes[i].wpts[wpn][5] = d;
 478                 wpn += 1;
 479
 480                 calc_hd_course_dist(planes[i].brg, planes[i].dist,
 481                                     planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 482                                     &course, &d);
 483         }
 484
 485         planes[i].wpts[wpn][0] = planes[i].brg;
 486         planes[i].wpts[wpn][1] = planes[i].dist;
 487         planes[i].wpts[wpn][2] = planes[i].alt;
 488         planes[i].wpts[wpn][4] = course;
 489         planes[i].wpts[wpn][5] = d;
 490         wpn += 1;
 491
 492         planes[i].wpn = wpn;
 493
 494         // Now check if legs are too short or if legs can be shortend
 495         // legs must be at least 2 flight minutes long
 496         double mdist = planes[i].spd / 60.0 * 2.0;
 497         for ( j=2; j<wpn-1; ++j ) {
 498                 if ( planes[i].wpts[j][1] < mdist) {
 499                 }
 500         }
 501
 502         // ====================
 503         // vertical navigation
 504         // ====================
 505         double alt = elev+3000.0;
 506         planes[i].wpts[1][2] = round_alt( true, alt );
 507         for ( j=2; j<wpn-1; ++j ) {
 508                 double dalt = planes[i].alt - planes[i].wpts[j-1][2];
 509                 if ( dalt > 0 ) {
 510                         alt = planes[i].wpts[j-1][2] +
 511                               (planes[i].wpts[j][5] / planes[i].spd) * 60.0 * planes[i].desc_rate;
 512                         planes[i].wpts[j][2] = round_alt( false, alt );
 513                         if ( planes[i].wpts[j][2] > planes[i].alt )
 514                                 planes[i].wpts[j][2] = round_alt( false, planes[i].alt );
 515                 }
 516                 else {
 517                         planes[i].wpts[j][2] = planes[i].wpts[1][2];
 518                 }
 519         }
 520
 521         cout << "Plane position: " << planes[i].brg << " " << planes[i].dist << endl;
 522         for ( j=0; j<wpn; ++j ) {
 523                 cout << "Waypoint " << j << endl;
 524                 cout << "------------------" << endl;
 525                 cout << planes[i].wpts[j][0] << "   " << planes[i].wpts[j][1]
 526                      << "   " << planes[i].wpts[j][2] << "   " << planes[i].wpts[j][5];
 527                 cout << endl << endl;
 528         }
 529
 530 }
 531
 532
 533 // ============================================================================
 534 // round altitude value to next highest/lowest 500 feet
 535 // ============================================================================
 536 double FGApproach::round_alt( const bool hl, double alt ) {
 537
 538   alt = alt/1000.0;
 539   if ( hl ) {
 540     if ( alt > (int)(alt)+0.5 ) alt = ((int)(alt)+1)*1000.0;
 541     else alt = ((int)(alt)+0.5)*1000.0;
 542   }
 543   else {
 544     if ( alt > (int)(alt)+0.5 ) alt = ((int)(alt)+0.5)*1000.0;
 545     else alt = ((int)(alt))*1000.0;
 546   }
 547
 548   return alt;
 549 }
 550
 551
 552 // ============================================================================
 553 // get active runway
 554 // ============================================================================
 555 void FGApproach::get_active_runway() {
 556         //cout << "Entering FGApproach::get_active_runway()\n";
 557
 558 #ifdef FG_WEATHERCM
 559   sgVec3 position = { lat, lon, elev };
 560   FGPhysicalProperty stationweather = WeatherDatabase->get(position);
 561 #else
 562   FGEnvironment stationweather =
 563       ((FGEnvironmentMgr *)globals->get_subsystem("environment"))
 564         ->getEnvironment(lat, lon, elev);
 565 #endif
 566
 567 #ifdef FG_WEATHERCM
 568   //Set the heading to into the wind
 569   double wind_x = stationweather.Wind[0];
 570   double wind_y = stationweather.Wind[1];
 571
 572   double speed = sqrt( wind_x*wind_x + wind_y*wind_y ) * SG_METER_TO_NM / (60.0*60.0);
 573   double hdg;
 574
 575   //If no wind use 270degrees
 576   if(speed == 0) {
 577     hdg = 270;
 578   } else {
 579     // //normalize the wind to get the direction
 580     //wind_x /= speed; wind_y /= speed;
 581
 582     hdg = - atan2 ( wind_x, wind_y ) * SG_RADIANS_TO_DEGREES ;
 583     if (hdg < 0.0)
 584       hdg += 360.0;
 585   }
 586 #else
 587   double hdg = stationweather.get_wind_from_heading_deg();
 588 #endif
 589
 590   FGRunway runway;
 591   if ( globals->get_runways()->search( ident, int(hdg), &runway) ) {
 592     active_runway = runway.rwy_no;
 593     active_rw_hdg = runway.heading;
 594     active_rw_lon = runway.lon;
 595     active_rw_lat = runway.lat;
 596     active_rw_len = runway.length;
 597     //cout << "Active runway is: " << active_runway << "  heading = "
 598     // << active_rw_hdg
 599     // << " lon = " << active_rw_lon
 600     // << " lat = " << active_rw_lat <<endl;
 601   }
 602   else cout << "FGRunways search failed\n";
 603
 604 }
 605
 606 // ========================================================================
 607 // update infos about plane
 608 // ========================================================================
 609 void FGApproach::update_plane_dat() {
 610
 611   //cout << "Update Approach " << ident << "   " << num_planes << " registered" << endl;
 612   // update plane positions
 613   int i;
 614   for (i=0; i<num_planes; i++) {
 615     planes[i].lon = lon_node->getDoubleValue();
 616     planes[i].lat = lat_node->getDoubleValue();
 617     planes[i].alt = elev_node->getDoubleValue();
 618     planes[i].hdg = hdg_node->getDoubleValue();
 619     planes[i].spd = speed_node->getDoubleValue();
 620
 621     /*Point3D aircraft = sgGeodToCart( Point3D(planes[i].lon*SGD_DEGREES_TO_RADIANS,
 622                                              planes[i].lat*SGD_DEGREES_TO_RADIANS,
 623                                              planes[i].alt*SG_FEET_TO_METER) );*/
 624     double course, distance;
 625     calc_gc_course_dist(Point3D(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0.0),
 626                         Point3D(planes[i].lon*SGD_DEGREES_TO_RADIANS,planes[i].lat*SGD_DEGREES_TO_RADIANS, 0.0 ),
 627                         &course, &distance);
 628     planes[i].dist = distance/SG_NM_TO_METER;
 629     planes[i].brg  = 360.0-course*SGD_RADIANS_TO_DEGREES;
 630
 631     //cout << "Plane Id: " << planes[i].ident << "  Distance to " << ident
 632     // << " is " << planes[i].dist << " miles   " << "Bearing " << planes[i].brg << endl;
 633
 634   }
 635 }
 636
 637 // =======================================================================
 638 // Add plane to Approach list
 639 // =======================================================================
 640 void FGApproach::AddPlane(string pid) {
 641
 642   int i;
 643   for ( i=0; i<num_planes; i++) {
 644     if ( planes[i].ident == pid) {
 645       //cout << "Plane already registered: " << planes[i].ident << ' ' << ident << ' ' << num_planes << endl;
 646       return;
 647     }
 648   }
 649   planes[num_planes].ident = pid;
 650   ++num_planes;
 651   //cout << "Plane added to list: " << ident << " " << num_planes << endl;
 652   return;
 653 }
 654
 655 // ================================================================================
 656 // closest distance between a point (h1,d1) and a straigt line (h2,d2,h3) in 2 dim.
 657 // ================================================================================
 658 double FGApproach::calc_psl_dist(const double &h1, const double &d1,
 659                                  const double &h2, const double &d2,
 660                                  const double &h3)
 661 {
 662   double a1 = h1 * SGD_DEGREES_TO_RADIANS;
 663   double a2 = h2 * SGD_DEGREES_TO_RADIANS;
 664   double a3 = h3 * SGD_DEGREES_TO_RADIANS;
 665   double x1 = cos(a1) * d1;
 666   double y1 = sin(a1) * d1;
 667   double x2 = cos(a2) * d2;
 668   double y2 = sin(a2) * d2;
 669   double x3 = cos(a3);
 670   double y3 = sin(a3);
 671
 672   // formula: dis = sqrt( (v1-v2)**2 - ((v1-v2)*v3)**2 ); vi = (xi,yi)
 673   double val1   = (x1-x2)*(x1-x2) + (y1-y2)*(y1-y2);
 674   double val2   = ((x1-x2)*x3 + (y1-y2)*y3) * ((x1-x2)*x3 + (y1-y2)*y3);
 675   double dis    = val1 - val2;
 676   // now get sign for offset
 677   //cout << x1 << " " << x2 << " " << y1 << " " << y2 << " "
 678   //     << x3 << " " << y3 << " "
 679   //     << val1 << " " << val2 << " " << dis << endl;
 680   x3 *= sqrt(val2);
 681   y3 *= sqrt(val2);
 682   double da = fabs(atan2(y3,x3) - atan2(y1-y2,x1-x2));
 683   if ( da > SGD_PI ) da -= 2*SGD_PI;
 684   if ( fabs(da) > SGD_PI/2.) {
 685     //if ( x3*(x1-x2) < 0.0 && y3*(y1-y2) < 0.0) {
 686     x3 *= -1.0;
 687     y3 *= -1.0;
 688   }
 689   //cout << x3 << " " << y3 << endl;
 690   double dis1   = x1-x2-x3;
 691   double dis2   = y1-y2-y3;
 692   dis = sqrt(dis);
 693   da = atan2(dis2,dis1);
 694   if ( da < 0.0 ) da  += 2*SGD_PI;
 695   if ( da < a3 )  dis *= -1.0;
 696   //cout << dis1 << " " << dis2 << " " << da*SGD_RADIANS_TO_DEGREES << " " << h3
 697   //     << " " << sqrt(dis1*dis1 + dis2*dis2) << " " << dis << endl;
 698   //cout << atan2(dis2,dis1)*SGD_RADIANS_TO_DEGREES << " " << dis << endl;
 699
 700   return dis;
 701 }
 702
 703
 704 // ========================================================================
 705 // Calculate new bear/dist given starting bear/dis, and offset radial,
 706 // and distance.
 707 // ========================================================================
 708 void FGApproach::calc_cd_head_dist(const double &h1, const double &d1,
 709                                    const double &course, const double &dist,
 710                                    double *h2, double *d2)
 711 {
 712   double a1 = h1 * SGD_DEGREES_TO_RADIANS;
 713   double a2 = course * SGD_DEGREES_TO_RADIANS;
 714   double x1 = cos(a1) * d1;
 715   double y1 = sin(a1) * d1;
 716   double x2 = cos(a2) * dist;
 717   double y2 = sin(a2) * dist;
 718
 719   *d2 = sqrt((x1+x2)*(x1+x2) + (y1+y2)*(y1+y2));
 720   *h2 = atan2( (y1+y2), (x1+x2) ) * SGD_RADIANS_TO_DEGREES;
 721   if ( *h2 < 0 ) *h2 = *h2+360;
 722 }
 723
 724
 725
 726 // ========================================================================
 727 // get heading and distance between two points; point1 ---> point2
 728 // ========================================================================
 729 void FGApproach::calc_hd_course_dist(const double &h1, const double &d1,
 730                                      const double &h2, const double &d2,
 731                                      double *course, double *dist)
 732 {
 733   double a1 = h1 * SGD_DEGREES_TO_RADIANS;
 734   double a2 = h2 * SGD_DEGREES_TO_RADIANS;
 735   double x1 = cos(a1) * d1;
 736   double y1 = sin(a1) * d1;
 737   double x2 = cos(a2) * d2;
 738   double y2 = sin(a2) * d2;
 739
 740   *dist   = sqrt( (y2-y1)*(y2-y1) + (x2-x1)*(x2-x1) );
 741   *course = atan2( (y2-y1), (x2-x1) ) * SGD_RADIANS_TO_DEGREES;
 742   if ( *course < 0 ) *course = *course+360;
 743   //cout << x1 << " " << y1 << " " << x2 << " " << y2 << " " << *dist << " " << *course << endl;
 744 }
 745
 746
 747
 748 int FGApproach::RemovePlane() {
 749
 750   // first check if anything has to be done
 751   bool rmplane = false;
 752   int i;
 753
 754   for (i=0; i<num_planes; i++) {
 755     if (planes[i].dist > range*SG_NM_TO_METER) {
 756       rmplane = true;
 757       break;
 758     }
 759   }
 760   if (!rmplane) return num_planes;
 761
 762   // now make a copy of the plane list
 763   PlaneApp tmp[max_planes];
 764   for (i=0; i<num_planes; i++) {
 765     tmp[i] = planes[i];
 766   }
 767
 768   int np = 0;
 769   // now check which planes are still in range
 770   for (i=0; i<num_planes; i++) {
 771     if (tmp[i].dist <= range*SG_NM_TO_METER) {
 772       planes[np] = tmp[i];
 773       np += 1;
 774     }
 775   }
 776   num_planes = np;
 777
 778   return num_planes;
 779 }