src/ATCDCL/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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20
  21 #ifdef HAVE_CONFIG_H
  22 #  include <config.h>
  23 #endif
  24
  25 #include <iostream>
  26
  27 #include "approach.hxx"
  28 #include "transmission.hxx"
  29 #include "transmissionlist.hxx"
  30 #include "ATCDialog.hxx"
  31
  32 #include <Airports/runways.hxx>
  33 #include <Airports/simple.hxx>
  34
  35 #include <simgear/constants.h>
  36 #include <simgear/math/polar3d.hxx>
  37 #include <simgear/misc/sg_path.hxx>
  38
  39 #include <Environment/environment_mgr.hxx>
  40 #include <Environment/environment.hxx>
  41
  42
  43 #include <GUI/gui.h>
  44
  45 using std::cout;
  46 using std::endl;
  47
  48 //Constructor
  49 FGApproach::FGApproach(){
  50   comm1_node = fgGetNode("/instrumentation/comm[0]/frequencies/selected-mhz", true);
  51   comm2_node = fgGetNode("/instrumentation/comm[1]/frequencies/selected-mhz", true);
  52
  53   _type = APPROACH;
  54
  55   num_planes = 0;
  56   lon_node   = fgGetNode("/position/longitude-deg", true);
  57   lat_node   = fgGetNode("/position/latitude-deg", true);
  58   elev_node  = fgGetNode("/position/altitude-ft", true);
  59   hdg_node   = fgGetNode("/orientation/heading-deg", true);
  60   speed_node = fgGetNode("/velocities/airspeed-kt", true);
  61   etime_node = fgGetNode("/sim/time/elapsed-sec", true);
  62
  63   first = true;
  64   active_runway = "";
  65   int i;
  66   for ( i=0; i<max_planes; i++) {
  67     planes[i].contact   = 0;
  68     planes[i].wpn       = 0;
  69     planes[i].dnwp      = -999.;
  70     planes[i].on_crs    = true;
  71     planes[i].turn_rate = 10.0;
  72     planes[i].desc_rate = 1000.0;
  73     planes[i].clmb_rate = 500.0;
  74     planes[i].tlm       = 0.0;
  75     planes[i].lmc.c1    = 0;
  76     planes[i].lmc.c2    = 0;
  77     planes[i].lmc.c3    = -1;
  78     planes[i].wp_change = false;
  79   }
  80 }
  81
  82 //Destructor
  83 FGApproach::~FGApproach(){
  84 }
  85
  86 void FGApproach::Init() {
  87 }
  88
  89
  90
  91 // ============================================================================
  92 // the main update function
  93 // ============================================================================
  94 void FGApproach::Update(double dt) {
  95
  96         const int max_trans = 20;
  97         FGTransmission tmissions[max_trans];
  98         int    wpn;
  99         atc_type station = APPROACH;
 100         TransCode code;
 101         TransPar TPar;
 102         int    i,j;
 103         //double course, d,
 104         double adif, datp;
 105         //char   buf[10];
 106         string message;
 107         //static string atcmsg1[10];
 108         //static string atcmsg2[10];
 109         string mentry;
 110         string transm;
 111         TransPar tpars;
 112         //static bool TransDisplayed = false;
 113
 114         update_plane_dat();
 115         if ( active_runway == "" ) get_active_runway();
 116
 117         double comm1_freq = comm1_node->getDoubleValue();
 118
 119         //bool DisplayTransmissions = true;
 120
 121         for (i=0; i<num_planes; i++) {
 122                 if ( planes[i].ident == "Player") {
 123                         station = APPROACH;
 124                         tpars.station = name;
 125                         tpars.callsign = "Player";
 126                         tpars.airport = ident;
 127
 128                         //cout << "ident = " << ident << " name = " << name << '\n';
 129
 130                         int num_trans = 0;
 131                         // is the frequency of the station tuned in?
 132                         if ( freq == (int)(comm1_freq*100.0 + 0.5) ) {
 133                                 current_transmissionlist->query_station( station, tmissions, max_trans, num_trans );
 134                                 // loop over all transmissions for station
 135                                 for ( j=0; j<=num_trans-1; j++ ) {
 136                                         code = tmissions[j].get_code();
 137                                         //cout << "code is " << code.c1 << "  " << code.c2 << "  " << code.c3 << '\n';
 138                                         // select proper transmissions
 139                                         if(code.c3 != 2) {    // DCL - hack to prevent request crossing airspace being displayed since this isn't implemented yet.
 140                                             if ( ( code.c2 == -1 && planes[i].lmc.c3 == 0 ) ||
 141                                                     ( code.c1 == 0  && code.c2 == planes[i].lmc.c2 ) ) {
 142                                                     mentry = current_transmissionlist->gen_text(station, code, tpars, false);
 143                                                     transm = current_transmissionlist->gen_text(station, code, tpars, true);
 144                                                     // is the transmission already registered?
 145                                                     if (!current_atcdialog->trans_reg( ident, transm, APPROACH )) {
 146                                                             current_atcdialog->add_entry( ident, transm, mentry, APPROACH, 0 );
 147                                                     }
 148                                             }
 149                                         }
 150                                 }
 151                         }
 152                 }
 153         }
 154
 155         for ( i=0; i<num_planes; i++ ) {
 156                 //cout << "TPar.airport = " << TPar.airport << " TPar.station = " << TPar.station << " TPar.callsign = " << TPar.callsign << '\n';
 157                 //if ( planes[i].ident == TPar.callsign && name == TPar.airport && TPar.station == "approach" ) {
 158                         //if ( TPar.request && TPar.intention == "landing" && ident == TPar.intid) {
 159                         if(planes[i].ident == "Player" && fgGetBool("/sim/atc/opt0")) {
 160                                 //cout << "Landing requested\n";
 161                                 fgSetBool("/sim/atc/opt0", false);
 162                                 planes[i].wpn = 0;
 163                                 // ===========================
 164                                 // === calculate waypoints ===
 165                                 // ===========================
 166                                 calc_wp( i );
 167                                 update_param( i );
 168                                 wpn = planes[i].wpn-1;
 169                                 planes[i].aalt = planes[i].wpts[wpn-1][2];
 170                                 planes[i].ahdg = planes[i].wpts[wpn][4];
 171
 172                                 // generate the message
 173                                 code.c1 = 1;
 174                                 code.c2 = 1;
 175                                 code.c3 = 0;
 176                                 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
 177                                 tpars.station = name;
 178                                 tpars.callsign = "Player";
 179                                 if ( adif < 0 ) tpars.tdir = 1;
 180                                 else            tpars.tdir = 2;
 181                                 tpars.heading = planes[i].ahdg;
 182                                 if      (planes[i].alt-planes[i].aalt > 100.0)  tpars.VDir = 1;
 183                                 else if (planes[i].alt-planes[i].aalt < -100.0) tpars.VDir = 3;
 184                                 else tpars.VDir = 2;
 185                                 tpars.alt = planes[i].aalt;
 186                                 message = current_transmissionlist->gen_text(station, code, tpars, true );
 187                                 //cout << message << '\n';
 188                                 set_message(message);
 189                                 planes[i].lmc = code;
 190                                 planes[i].tlm = etime_node->getDoubleValue();
 191                                 planes[i].on_crs = true;
 192                                 planes[i].contact = 1;
 193                         }
 194                 //}
 195
 196                 //if(1) {
 197                 if ( planes[i].contact == 1 ) {
 198                         // =========================
 199                         // === update parameters ===
 200                         // =========================
 201                         update_param( i );
 202                         //cout << planes[i].brg << " " << planes[i].dist << " " << planes[i].wpts[wpn+1][0]
 203                         //<< " " << planes[i].wpts[wpn+1][1] << " " << planes[i].wpts[wpn+1][4]
 204                         //cout << wpn << " distance to current course = " << planes[i].dcc << endl;
 205                         //cout << etime_node->getDoubleValue() << endl;
 206
 207                         // =========================
 208                         // === reached waypoint? ===
 209                         // =========================
 210                         wpn = planes[i].wpn-2;
 211                         adif = angle_diff_deg( planes[i].hdg, planes[i].wpts[wpn][4] )
 212                         * SGD_DEGREES_TO_RADIANS;
 213                         datp = 2*sin(fabs(adif)/2.0)*sin(fabs(adif)/2.0) *
 214                                planes[i].spd/3600. * planes[i].turn_rate +
 215                                planes[i].spd/3600. * 3.0;
 216                         //cout << adif/SGD_DEGREES_TO_RADIANS << " "
 217                         //     << datp << " " << planes[i].dnc << " " << planes[i].dcc <<endl;
 218                         if ( fabs(planes[i].dnc) < datp ) {
 219                         //if ( fabs(planes[i].dnc) < 0.3 && planes[i].dnwp < 1.0 ) {
 220                                 //cout << "Reached next waypoint!\n";
 221                                 planes[i].wpn -= 1;
 222                                 wpn = planes[i].wpn-1;
 223                                 planes[i].ahdg = planes[i].wpts[wpn][4];
 224                                 planes[i].aalt = planes[i].wpts[wpn-1][2];
 225                                 planes[i].wp_change = true;
 226
 227                                 // generate the message
 228                                 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
 229                                 tpars.station = name;
 230                                 tpars.callsign = "Player";
 231                                 if ( adif < 0 ) tpars.tdir = 1;
 232                                 else            tpars.tdir = 2;
 233                                 tpars.heading = planes[i].ahdg;
 234
 235                                 if ( wpn-1 != 0) {
 236                                         code.c1 = 1;
 237                                         code.c2 = 1;
 238                                         code.c3 = 0;
 239                                         if      (planes[i].alt-planes[i].aalt > 100.0)  tpars.VDir = 1;
 240                                         else if (planes[i].alt-planes[i].aalt < -100.0) tpars.VDir = 3;
 241                                         else tpars.VDir = 2;
 242                                         tpars.alt = planes[i].aalt;
 243                                         message = current_transmissionlist->gen_text(station, code, tpars, true );
 244                                         //cout << "Approach transmitting...\n";
 245                                         //cout << message << endl;
 246                                         set_message(message);
 247                                 }
 248                                 else {
 249                                         code.c1 = 1;
 250                                         code.c2 = 3;
 251                                         code.c3 = 0;
 252                                         tpars.runway = active_runway;
 253                                         message = current_transmissionlist->gen_text(station, code, tpars, true);
 254                                         //cout << "Approach transmitting 2 ...\n";
 255                                         //cout << message << endl;
 256                                         set_message(message);
 257                                 }
 258                                 planes[i].lmc = code;
 259                                 planes[i].tlm = etime_node->getDoubleValue();
 260                                 planes[i].on_crs = true;
 261
 262                                 update_param( i );
 263                         }
 264
 265                         // =========================
 266                         // === come off course ? ===
 267                         // =========================
 268                         if ( fabs(planes[i].dcc) > 1.0 &&
 269                            ( !planes[i].wp_change || etime_node->getDoubleValue() - planes[i].tlm > tbm ) ) {
 270                                 //cout << "Off course!\n";
 271                                 if ( planes[i].on_crs ) {
 272                                         if ( planes[i].dcc < 0) {
 273                                                 planes[i].ahdg += 30.0;
 274                                         }
 275                                         else {
 276                                                 planes[i].ahdg -= 30.0;
 277                                         }
 278                                         if (planes[i].ahdg > 360.0) planes[i].ahdg -= 360.0;
 279                                         else if (planes[i].ahdg < 0.0) planes[i].ahdg += 360.0;
 280                                 }
 281                                 //cout << planes[i].on_crs << " "
 282                                 //     << angle_diff_deg( planes[i].hdg, planes[i].ahdg) << " "
 283                                 //     << etime_node->getDoubleValue() << " "
 284                                 //     << planes[i].tlm << endl;
 285                                 // generate the message
 286                                 if ( planes[i].on_crs ||
 287                                    ( fabs(angle_diff_deg( planes[i].hdg, planes[i].ahdg )) >  30.0  &&
 288                                     etime_node->getDoubleValue() - planes[i].tlm > tbm) ) {
 289                                         // generate the message
 290                                         code.c1 = 1;
 291                                         code.c2 = 4;
 292                                         code.c3 = 0;
 293                                         adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
 294                                         tpars.station = name;
 295                                         tpars.callsign = "Player";
 296                                         tpars.miles   = fabs(planes[i].dcc);
 297                                         if ( adif < 0 ) tpars.tdir = 1;
 298                                         else            tpars.tdir = 2;
 299                                         tpars.heading = planes[i].ahdg;
 300                                         message = current_transmissionlist->gen_text(station, code, tpars, true);
 301                                         //cout << "Approach transmitting 3 ...\n";
 302                                         //cout << message << '\n';
 303                                         set_message(message);
 304                                         planes[i].lmc = code;
 305                                         planes[i].tlm = etime_node->getDoubleValue();
 306                                 }
 307
 308                                 planes[i].on_crs = false;
 309                         }
 310                         else if ( !planes[i].on_crs ) {
 311                                 //cout << "Off course 2!\n";
 312                                 wpn = planes[i].wpn-1;
 313                                 adif = angle_diff_deg( planes[i].hdg, planes[i].wpts[wpn][4] )
 314                                        * SGD_DEGREES_TO_RADIANS;
 315                                 datp = 2*sin(fabs(adif)/2.0)*sin(fabs(adif)/2.0) *
 316                                 planes[i].spd/3600. * planes[i].turn_rate +
 317                                 planes[i].spd/3600. * 3.0;
 318                                 if ( fabs(planes[i].dcc) < datp ) {
 319                                         planes[i].ahdg = fabs(planes[i].wpts[wpn][4]);
 320
 321                                         // generate the message
 322                                         code.c1 = 1;
 323                                         code.c2 = 2;
 324                                         code.c3 = 0;
 325                                         tpars.station = name;
 326                                         tpars.callsign = "Player";
 327                                         if ( adif < 0 ) tpars.tdir = 1;
 328                                         else            tpars.tdir = 2;
 329                                         tpars.heading = planes[i].ahdg;
 330                                         message = current_transmissionlist->gen_text(station, code, tpars, true);
 331                                         //cout << "Approach transmitting 4 ...\n";
 332                                         //cout << message << '\n';
 333                                         set_message(message);
 334                                         planes[i].lmc = code;
 335                                         planes[i].tlm = etime_node->getDoubleValue();
 336
 337                                         planes[i].on_crs = true;
 338                                 }
 339                         }
 340                         else if ( planes[i].wp_change  ) {
 341                                 planes[i].wp_change = false;
 342                         }
 343
 344                         // ===================================================================
 345                         // === Less than two minutes away from touchdown? -> Contact Tower ===
 346                         // ===================================================================
 347                         if ( planes[i].wpn == 2 && planes[i].dnwp < planes[i].spd/60.*2.0 ) {
 348
 349                                 double freq = 121.95;   // Hardwired - FIXME
 350                                 // generate message
 351                                 code.c1 = 1;
 352                                 code.c2 = 5;
 353                                 code.c3 = 0;
 354                                 tpars.station = name;
 355                                 tpars.callsign = "Player";
 356                                 tpars.freq    = freq;
 357                                 message = current_transmissionlist->gen_text(station, code, tpars, true);
 358                                 //cout << "Approach transmitting 5 ...\n";
 359                                 //cout << message << '\n';
 360                                 set_message(message);
 361                                 planes[i].lmc = code;
 362                                 planes[i].tlm = etime_node->getDoubleValue();
 363
 364                                 planes[i].contact = 2;
 365                         }
 366                 }
 367         }
 368 }
 369
 370
 371 // ============================================================================
 372 // update course parameters
 373 // ============================================================================
 374 void FGApproach::update_param( const int &i ) {
 375
 376   double course, d;
 377
 378   int wpn = planes[i].wpn-1;            // this is the current waypoint
 379
 380   planes[i].dcc  = calc_psl_dist(planes[i].brg, planes[i].dist,
 381                                  planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
 382                                  planes[i].wpts[wpn][4]);
 383   planes[i].dnc  = calc_psl_dist(planes[i].brg, planes[i].dist,
 384                                  planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 385                                  planes[i].wpts[wpn-1][4]);
 386   calc_hd_course_dist(planes[i].brg, planes[i].dist,
 387                       planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 388                       &course, &d);
 389   planes[i].dnwp = d;
 390
 391 }
 392
 393 // ============================================================================
 394 // smallest difference between two angles in degree
 395 // difference is negative if a1 > a2 and positive if a2 > a1
 396 // ===========================================================================
 397 double FGApproach::angle_diff_deg( const double &a1, const double &a2) {
 398
 399   double a3 = a2 - a1;
 400   if (a3 < 180.0) a3 += 360.0;
 401   if (a3 > 180.0) a3 -= 360.0;
 402
 403   return a3;
 404 }
 405
 406 // ============================================================================
 407 // calculate waypoints
 408 // ============================================================================
 409 void FGApproach::calc_wp( const int &i ) {
 410
 411         int j;
 412         double course, d, cd, a1;
 413
 414         int wpn = planes[i].wpn;
 415         // waypoint 0: Threshold of active runway
 416         calc_gc_course_dist(Point3D(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0.0),
 417                             Point3D(active_rw_lon*SGD_DEGREES_TO_RADIANS,active_rw_lat*SGD_DEGREES_TO_RADIANS, 0.0 ),
 418                             &course, &d);
 419         double d1 = active_rw_hdg+180.0;
 420         if ( d1 > 360.0 ) d1 -=360.0;
 421         calc_cd_head_dist(360.0-course*SGD_RADIANS_TO_DEGREES, d/SG_NM_TO_METER,
 422                           d1, active_rw_len/SG_NM_TO_METER/2.0,
 423                           &planes[i].wpts[wpn][0], &planes[i].wpts[wpn][1]);
 424         planes[i].wpts[wpn][2] = elev;
 425         planes[i].wpts[wpn][4] = 0.0;
 426         planes[i].wpts[wpn][5] = 0.0;
 427         wpn += 1;
 428
 429         // ======================
 430         // horizontal navigation
 431         // ======================
 432         // waypoint 1: point for turning onto final
 433         calc_cd_head_dist(planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1], d1, lfl,
 434                           &planes[i].wpts[wpn][0], &planes[i].wpts[wpn][1]);
 435         calc_hd_course_dist(planes[i].wpts[wpn][0],   planes[i].wpts[wpn][1],
 436                             planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 437                             &course, &d);
 438         planes[i].wpts[wpn][4] = course;
 439         planes[i].wpts[wpn][5] = d;
 440         wpn += 1;
 441
 442         // calculate course and distance from plane position to waypoint 1
 443         calc_hd_course_dist(planes[i].brg, planes[i].dist, planes[i].wpts[1][0],
 444                             planes[i].wpts[1][1], &course, &d);
 445         // check if airport is not between plane and waypoint 1 and
 446         // DCA to airport on course to waypoint 1 is larger than 10 miles
 447         double zero = 0.0;
 448         if ( fabs(angle_diff_deg( planes[i].wpts[1][0], planes[i].brg  )) < 90.0 ||
 449                 calc_psl_dist( zero, zero, planes[i].brg, planes[i].dist, course ) > 10.0 ) {
 450                 // check if turning angle at waypoint 1 would be > max_ta
 451                 if ( fabs(angle_diff_deg( planes[i].wpts[1][4], course )) > max_ta ) {
 452                         cd = calc_psl_dist(planes[i].brg, planes[i].dist,
 453                              planes[i].wpts[1][0], planes[i].wpts[1][1],
 454                              planes[i].wpts[1][4]);
 455                         a1 = atan2(cd,planes[i].wpts[1][1]);
 456                         planes[i].wpts[wpn][0] = planes[i].wpts[1][0] - a1/SGD_DEGREES_TO_RADIANS;
 457                         if ( planes[i].wpts[wpn][0] < 0.0)   planes[i].wpts[wpn][0] += 360.0;
 458                         if ( planes[i].wpts[wpn][0] > 360.0) planes[i].wpts[wpn][0] -= 360.0;
 459                         planes[i].wpts[wpn][1] = fabs(cd) / sin(fabs(a1));
 460                         calc_hd_course_dist(planes[i].wpts[wpn][0],   planes[i].wpts[wpn][1],
 461                                             planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 462                                             &course, &d);
 463                         planes[i].wpts[wpn][4] = course;
 464                         planes[i].wpts[wpn][5] = d;
 465                         wpn += 1;
 466
 467                         calc_hd_course_dist(planes[i].brg, planes[i].dist, planes[i].wpts[wpn-1][0],
 468                                             planes[i].wpts[wpn-1][1], &course, &d);
 469                 }
 470         } else {
 471                 double leg = 10.0;
 472                 a1 = atan2(planes[i].wpts[1][1], leg );
 473
 474                 if ( angle_diff_deg(planes[i].brg,planes[i].wpts[1][0]) < 0 )
 475                         planes[i].wpts[wpn][0] = planes[i].wpts[1][0] + a1/SGD_DEGREES_TO_RADIANS;
 476                 else planes[i].wpts[wpn][0] = planes[i].wpts[1][0] - a1/SGD_DEGREES_TO_RADIANS;
 477
 478                 planes[i].wpts[wpn][1] = sqrt( planes[i].wpts[1][1]*planes[i].wpts[1][1] + leg*leg );
 479                 calc_hd_course_dist(planes[i].wpts[wpn][0],   planes[i].wpts[wpn][1],
 480                                     planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 481                                     &course, &d);
 482                 planes[i].wpts[wpn][4] = course;
 483                 planes[i].wpts[wpn][5] = d;
 484                 wpn += 1;
 485
 486                 calc_hd_course_dist(planes[i].brg, planes[i].dist,
 487                                     planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
 488                                     &course, &d);
 489         }
 490
 491         planes[i].wpts[wpn][0] = planes[i].brg;
 492         planes[i].wpts[wpn][1] = planes[i].dist;
 493         planes[i].wpts[wpn][2] = planes[i].alt;
 494         planes[i].wpts[wpn][4] = course;
 495         planes[i].wpts[wpn][5] = d;
 496         wpn += 1;
 497
 498         planes[i].wpn = wpn;
 499
 500         // Now check if legs are too short or if legs can be shortend
 501         // legs must be at least 2 flight minutes long
 502         double mdist = planes[i].spd / 60.0 * 2.0;
 503         for ( j=2; j<wpn-1; ++j ) {
 504                 if ( planes[i].wpts[j][1] < mdist) {
 505                 }
 506         }
 507
 508         // ====================
 509         // vertical navigation
 510         // ====================
 511         double alt = elev+3000.0;
 512         planes[i].wpts[1][2] = round_alt( true, alt );
 513         for ( j=2; j<wpn-1; ++j ) {
 514                 double dalt = planes[i].alt - planes[i].wpts[j-1][2];
 515                 if ( dalt > 0 ) {
 516                         alt = planes[i].wpts[j-1][2] +
 517                               (planes[i].wpts[j][5] / planes[i].spd) * 60.0 * planes[i].desc_rate;
 518                         planes[i].wpts[j][2] = round_alt( false, alt );
 519                         if ( planes[i].wpts[j][2] > planes[i].alt )
 520                                 planes[i].wpts[j][2] = round_alt( false, planes[i].alt );
 521                 }
 522                 else {
 523                         planes[i].wpts[j][2] = planes[i].wpts[1][2];
 524                 }
 525         }
 526
 527         cout << "Plane position: " << planes[i].brg << " " << planes[i].dist << endl;
 528         for ( j=0; j<wpn; ++j ) {
 529                 cout << "Waypoint " << j << endl;
 530                 cout << "------------------" << endl;
 531                 cout << planes[i].wpts[j][0] << "   " << planes[i].wpts[j][1]
 532                      << "   " << planes[i].wpts[j][2] << "   " << planes[i].wpts[j][5];
 533                 cout << endl << endl;
 534         }
 535
 536 }
 537
 538
 539 // ============================================================================
 540 // round altitude value to next highest/lowest 500 feet
 541 // ============================================================================
 542 double FGApproach::round_alt( const bool hl, double alt ) {
 543
 544   alt = alt/1000.0;
 545   if ( hl ) {
 546     if ( alt > (int)(alt)+0.5 ) alt = ((int)(alt)+1)*1000.0;
 547     else alt = ((int)(alt)+0.5)*1000.0;
 548   }
 549   else {
 550     if ( alt > (int)(alt)+0.5 ) alt = ((int)(alt)+0.5)*1000.0;
 551     else alt = ((int)(alt))*1000.0;
 552   }
 553
 554   return alt;
 555 }
 556
 557
 558 // ============================================================================
 559 // get active runway
 560 // ============================================================================
 561 void FGApproach::get_active_runway() {
 562         //cout << "Entering FGApproach::get_active_runway()\n";
 563
 564   const FGAirport* apt = fgFindAirportID(ident);
 565   assert(apt);
 566   FGRunway* runway = apt->getActiveRunwayForUsage();
 567
 568   active_runway = runway->ident();
 569   active_rw_hdg = runway->headingDeg();
 570   active_rw_lon = runway->longitude();
 571   active_rw_lat = runway->latitude();
 572   active_rw_len = runway->lengthFt();
 573 }
 574
 575 // ========================================================================
 576 // update infos about plane
 577 // ========================================================================
 578 void FGApproach::update_plane_dat() {
 579
 580   //cout << "Update Approach " << ident << "   " << num_planes << " registered" << endl;
 581   // update plane positions
 582   int i;
 583   for (i=0; i<num_planes; i++) {
 584     planes[i].lon = lon_node->getDoubleValue();
 585     planes[i].lat = lat_node->getDoubleValue();
 586     planes[i].alt = elev_node->getDoubleValue();
 587     planes[i].hdg = hdg_node->getDoubleValue();
 588     planes[i].spd = speed_node->getDoubleValue();
 589
 590     /*Point3D aircraft = sgGeodToCart( Point3D(planes[i].lon*SGD_DEGREES_TO_RADIANS,
 591                                              planes[i].lat*SGD_DEGREES_TO_RADIANS,
 592                                              planes[i].alt*SG_FEET_TO_METER) );*/
 593     double course, distance;
 594     calc_gc_course_dist(Point3D(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0.0),
 595                         Point3D(planes[i].lon*SGD_DEGREES_TO_RADIANS,planes[i].lat*SGD_DEGREES_TO_RADIANS, 0.0 ),
 596                         &course, &distance);
 597     planes[i].dist = distance/SG_NM_TO_METER;
 598     planes[i].brg  = 360.0-course*SGD_RADIANS_TO_DEGREES;
 599
 600     //cout << "Plane Id: " << planes[i].ident << "  Distance to " << ident
 601     // << " is " << planes[i].dist << " miles   " << "Bearing " << planes[i].brg << endl;
 602
 603   }
 604 }
 605
 606 // =======================================================================
 607 // Add plane to Approach list
 608 // =======================================================================
 609 void FGApproach::AddPlane(const string& pid) {
 610
 611   int i;
 612   for ( i=0; i<num_planes; i++) {
 613     if ( planes[i].ident == pid) {
 614       //cout << "Plane already registered: " << planes[i].ident << ' ' << ident << ' ' << num_planes << endl;
 615       return;
 616     }
 617   }
 618   planes[num_planes].ident = pid;
 619   ++num_planes;
 620   //cout << "Plane added to list: " << ident << " " << num_planes << endl;
 621   return;
 622 }
 623
 624 // ================================================================================
 625 // closest distance between a point (h1,d1) and a straigt line (h2,d2,h3) in 2 dim.
 626 // ================================================================================
 627 double FGApproach::calc_psl_dist(const double &h1, const double &d1,
 628                                  const double &h2, const double &d2,
 629                                  const double &h3)
 630 {
 631   double a1 = h1 * SGD_DEGREES_TO_RADIANS;
 632   double a2 = h2 * SGD_DEGREES_TO_RADIANS;
 633   double a3 = h3 * SGD_DEGREES_TO_RADIANS;
 634   double x1 = cos(a1) * d1;
 635   double y1 = sin(a1) * d1;
 636   double x2 = cos(a2) * d2;
 637   double y2 = sin(a2) * d2;
 638   double x3 = cos(a3);
 639   double y3 = sin(a3);
 640
 641   // formula: dis = sqrt( (v1-v2)**2 - ((v1-v2)*v3)**2 ); vi = (xi,yi)
 642   double val1   = (x1-x2)*(x1-x2) + (y1-y2)*(y1-y2);
 643   double val2   = ((x1-x2)*x3 + (y1-y2)*y3) * ((x1-x2)*x3 + (y1-y2)*y3);
 644   double dis    = val1 - val2;
 645   // now get sign for offset
 646   //cout << x1 << " " << x2 << " " << y1 << " " << y2 << " "
 647   //     << x3 << " " << y3 << " "
 648   //     << val1 << " " << val2 << " " << dis << endl;
 649   x3 *= sqrt(val2);
 650   y3 *= sqrt(val2);
 651   double da = fabs(atan2(y3,x3) - atan2(y1-y2,x1-x2));
 652   if ( da > SGD_PI ) da -= SGD_2PI;
 653   if ( fabs(da) > SGD_PI_2) {
 654     //if ( x3*(x1-x2) < 0.0 && y3*(y1-y2) < 0.0) {
 655     x3 *= -1.0;
 656     y3 *= -1.0;
 657   }
 658   //cout << x3 << " " << y3 << endl;
 659   double dis1   = x1-x2-x3;
 660   double dis2   = y1-y2-y3;
 661   dis = sqrt(dis);
 662   da = atan2(dis2,dis1);
 663   if ( da < 0.0 ) da  += SGD_2PI;
 664   if ( da < a3 )  dis *= -1.0;
 665   //cout << dis1 << " " << dis2 << " " << da*SGD_RADIANS_TO_DEGREES << " " << h3
 666   //     << " " << sqrt(dis1*dis1 + dis2*dis2) << " " << dis << endl;
 667   //cout << atan2(dis2,dis1)*SGD_RADIANS_TO_DEGREES << " " << dis << endl;
 668
 669   return dis;
 670 }
 671
 672
 673 // ========================================================================
 674 // Calculate new bear/dist given starting bear/dis, and offset radial,
 675 // and distance.
 676 // ========================================================================
 677 void FGApproach::calc_cd_head_dist(const double &h1, const double &d1,
 678                                    const double &course, const double &dist,
 679                                    double *h2, double *d2)
 680 {
 681   double a1 = h1 * SGD_DEGREES_TO_RADIANS;
 682   double a2 = course * SGD_DEGREES_TO_RADIANS;
 683   double x1 = cos(a1) * d1;
 684   double y1 = sin(a1) * d1;
 685   double x2 = cos(a2) * dist;
 686   double y2 = sin(a2) * dist;
 687
 688   *d2 = sqrt((x1+x2)*(x1+x2) + (y1+y2)*(y1+y2));
 689   *h2 = atan2( (y1+y2), (x1+x2) ) * SGD_RADIANS_TO_DEGREES;
 690   if ( *h2 < 0 ) *h2 = *h2+360;
 691 }
 692
 693
 694
 695 // ========================================================================
 696 // get heading and distance between two points; point1 ---> point2
 697 // ========================================================================
 698 void FGApproach::calc_hd_course_dist(const double &h1, const double &d1,
 699                                      const double &h2, const double &d2,
 700                                      double *course, double *dist)
 701 {
 702   double a1 = h1 * SGD_DEGREES_TO_RADIANS;
 703   double a2 = h2 * SGD_DEGREES_TO_RADIANS;
 704   double x1 = cos(a1) * d1;
 705   double y1 = sin(a1) * d1;
 706   double x2 = cos(a2) * d2;
 707   double y2 = sin(a2) * d2;
 708
 709   *dist   = sqrt( (y2-y1)*(y2-y1) + (x2-x1)*(x2-x1) );
 710   *course = atan2( (y2-y1), (x2-x1) ) * SGD_RADIANS_TO_DEGREES;
 711   if ( *course < 0 ) *course = *course+360;
 712   //cout << x1 << " " << y1 << " " << x2 << " " << y2 << " " << *dist << " " << *course << endl;
 713 }
 714
 715
 716
 717 int FGApproach::RemovePlane() {
 718
 719   // first check if anything has to be done
 720   bool rmplane = false;
 721   int i;
 722
 723   for (i=0; i<num_planes; i++) {
 724     if (planes[i].dist > range*SG_NM_TO_METER) {
 725       rmplane = true;
 726       break;
 727     }
 728   }
 729   if (!rmplane) return num_planes;
 730
 731   // now make a copy of the plane list
 732   PlaneApp tmp[max_planes];
 733   for (i=0; i<num_planes; i++) {
 734     tmp[i] = planes[i];
 735   }
 736
 737   int np = 0;
 738   // now check which planes are still in range
 739   for (i=0; i<num_planes; i++) {
 740     if (tmp[i].dist <= range*SG_NM_TO_METER) {
 741       planes[np] = tmp[i];
 742       np += 1;
 743     }
 744   }
 745   num_planes = np;
 746
 747   return num_planes;
 748 }
 749
 750
 751 void FGApproach::set_message(const string &msg)
 752 {
 753   fgSetString("/sim/messages/approach", msg.c_str());
 754 }
 755