1 // FGApproach - a class to provide approach control at larger airports.
3 // Written by Alexander Kappes, started March 2002.
5 // Copyright (C) 2002 Alexander Kappes
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.
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.
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.
21 #include "approach.hxx"
22 #include "transmission.hxx"
23 #include "transmissionlist.hxx"
24 #include "ATCdisplay.hxx"
25 #include "ATCDialog.hxx"
27 #include <Airports/runways.hxx>
28 #include <simgear/misc/sg_path.hxx>
31 # include <WeatherCM/FGLocalWeatherDatabase.h>
33 # include <Environment/environment_mgr.hxx>
34 # include <Environment/environment.hxx>
41 FGApproach::FGApproach(){
42 comm1_node = fgGetNode("/radios/comm[0]/frequencies/selected-mhz", true);
43 comm2_node = fgGetNode("/radios/comm[1]/frequencies/selected-mhz", true);
46 lon_node = fgGetNode("/position/longitude-deg", true);
47 lat_node = fgGetNode("/position/latitude-deg", true);
48 elev_node = fgGetNode("/position/altitude-ft", true);
49 hdg_node = fgGetNode("/orientation/heading-deg", true);
50 speed_node = fgGetNode("/velocities/airspeed-kt", true);
51 etime_node = fgGetNode("/sim/time/elapsed-ms", true);
56 for ( i=0; i<max_planes; i++) {
57 planes[i].contact = 0;
59 planes[i].dnwp = -999.;
60 planes[i].on_crs = true;
61 planes[i].turn_rate = 10.0;
62 planes[i].desc_rate = 1000.0;
63 planes[i].clmb_rate = 500.0;
67 planes[i].lmc.c3 = -1;
68 planes[i].wp_change = false;
73 FGApproach::~FGApproach(){
76 void FGApproach::Init() {
82 // ============================================================================
83 // the main update function
84 // ============================================================================
85 void FGApproach::Update(double dt) {
87 const int max_trans = 20;
88 FGTransmission tmissions[max_trans];
98 //static string atcmsg1[10];
99 //static string atcmsg2[10];
103 //static bool TransDisplayed = false;
106 if ( active_runway == "" ) get_active_runway();
108 double comm1_freq = comm1_node->getDoubleValue();
110 //bool DisplayTransmissions = true;
112 for (i=0; i<num_planes; i++) {
113 if ( planes[i].ident == "Player") {
115 tpars.station = name;
116 tpars.callsign = "Player";
117 tpars.airport = ident;
119 //cout << "ident = " << ident << " name = " << name << '\n';
122 // is the frequency of the station tuned in?
123 if ( freq == (int)(comm1_freq*100.0 + 0.5) ) {
124 current_transmissionlist->query_station( station, tmissions, max_trans, num_trans );
125 // loop over all transmissions for station
126 for ( j=0; j<=num_trans-1; j++ ) {
127 code = tmissions[j].get_code();
128 //cout << "code is " << code.c1 << " " << code.c2 << " " << code.c3 << '\n';
129 // select proper transmissions
130 if(code.c3 != 2) { // DCL - hack to prevent request crossing airspace being displayed since this isn't implemented yet.
131 if ( ( code.c2 == -1 && planes[i].lmc.c3 == 0 ) ||
132 ( code.c1 == 0 && code.c2 == planes[i].lmc.c2 ) ) {
133 mentry = current_transmissionlist->gen_text(station, code, tpars, false);
134 transm = current_transmissionlist->gen_text(station, code, tpars, true);
135 // is the transmission already registered?
136 if (!current_atcdialog->trans_reg( ident, transm )) {
137 current_atcdialog->add_entry( ident, transm, mentry );
146 for ( i=0; i<num_planes; i++ ) {
147 //cout << "TPar.airport = " << TPar.airport << " TPar.station = " << TPar.station << " TPar.callsign = " << TPar.callsign << '\n';
148 //if ( planes[i].ident == TPar.callsign && name == TPar.airport && TPar.station == "approach" ) {
149 //if ( TPar.request && TPar.intention == "landing" && ident == TPar.intid) {
150 if(planes[i].ident == "Player" && fgGetBool("/sim/atc/opt0")) {
151 //cout << "Landing requested\n";
152 fgSetBool("/sim/atc/opt0", false);
154 // ===========================
155 // === calculate waypoints ===
156 // ===========================
159 wpn = planes[i].wpn-1;
160 planes[i].aalt = planes[i].wpts[wpn-1][2];
161 planes[i].ahdg = planes[i].wpts[wpn][4];
163 // generate the message
167 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
168 tpars.station = name;
169 tpars.callsign = "Player";
170 if ( adif < 0 ) tpars.tdir = 1;
172 tpars.heading = planes[i].ahdg;
173 if (planes[i].alt-planes[i].aalt > 100.0) tpars.VDir = 1;
174 else if (planes[i].alt-planes[i].aalt < -100.0) tpars.VDir = 3;
176 tpars.alt = planes[i].aalt;
177 message = current_transmissionlist->gen_text(station, code, tpars, true );
178 //cout << message << '\n';
179 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
180 planes[i].lmc = code;
181 planes[i].tlm = etime_node->getDoubleValue();
182 planes[i].on_crs = true;
183 planes[i].contact = 1;
188 if ( planes[i].contact == 1 ) {
189 // =========================
190 // === update parameters ===
191 // =========================
193 //cout << planes[i].brg << " " << planes[i].dist << " " << planes[i].wpts[wpn+1][0]
194 //<< " " << planes[i].wpts[wpn+1][1] << " " << planes[i].wpts[wpn+1][4]
195 //cout << wpn << " distance to current course = " << planes[i].dcc << endl;
196 //cout << etime_node->getDoubleValue() << endl;
198 // =========================
199 // === reached waypoint? ===
200 // =========================
201 wpn = planes[i].wpn-2;
202 adif = angle_diff_deg( planes[i].hdg, planes[i].wpts[wpn][4] )
203 * SGD_DEGREES_TO_RADIANS;
204 datp = 2*sin(fabs(adif)/2.0)*sin(fabs(adif)/2.0) *
205 planes[i].spd/3600. * planes[i].turn_rate +
206 planes[i].spd/3600. * 3.0;
207 //cout << adif/SGD_DEGREES_TO_RADIANS << " "
208 // << datp << " " << planes[i].dnc << " " << planes[i].dcc <<endl;
209 if ( fabs(planes[i].dnc) < datp ) {
210 //if ( fabs(planes[i].dnc) < 0.3 && planes[i].dnwp < 1.0 ) {
211 //cout << "Reached next waypoint!\n";
213 wpn = planes[i].wpn-1;
214 planes[i].ahdg = planes[i].wpts[wpn][4];
215 planes[i].aalt = planes[i].wpts[wpn-1][2];
216 planes[i].wp_change = true;
218 // generate the message
219 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
220 tpars.station = name;
221 tpars.callsign = "Player";
222 if ( adif < 0 ) tpars.tdir = 1;
224 tpars.heading = planes[i].ahdg;
230 if (planes[i].alt-planes[i].aalt > 100.0) tpars.VDir = 1;
231 else if (planes[i].alt-planes[i].aalt < -100.0) tpars.VDir = 3;
233 tpars.alt = planes[i].aalt;
234 message = current_transmissionlist->gen_text(station, code, tpars, true );
235 //cout << "Approach transmitting...\n";
236 //cout << message << '\n';
237 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
244 tpars.runway = active_runway;
245 message = current_transmissionlist->gen_text(station, code, tpars, true);
246 //cout << "Approach transmitting 2 ...\n";
247 //cout << message << '\n';
248 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
250 planes[i].lmc = code;
251 planes[i].tlm = etime_node->getDoubleValue();
252 planes[i].on_crs = true;
257 // =========================
258 // === come off course ? ===
259 // =========================
260 if ( fabs(planes[i].dcc) > 1.0 &&
261 ( !planes[i].wp_change || etime_node->getDoubleValue() - planes[i].tlm > tbm ) ) {
262 //cout << "Off course!\n";
263 if ( planes[i].on_crs ) {
264 if ( planes[i].dcc < 0) {
265 planes[i].ahdg += 30.0;
268 planes[i].ahdg -= 30.0;
270 if (planes[i].ahdg > 360.0) planes[i].ahdg -= 360.0;
271 else if (planes[i].ahdg < 0.0) planes[i].ahdg += 360.0;
273 //cout << planes[i].on_crs << " "
274 // << angle_diff_deg( planes[i].hdg, planes[i].ahdg) << " "
275 // << etime_node->getDoubleValue() << " "
276 // << planes[i].tlm << endl;
277 // generate the message
278 if ( planes[i].on_crs ||
279 ( fabs(angle_diff_deg( planes[i].hdg, planes[i].ahdg )) > 30.0 &&
280 etime_node->getDoubleValue() - planes[i].tlm > tbm) ) {
281 // generate the message
285 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
286 tpars.station = name;
287 tpars.callsign = "Player";
288 tpars.miles = fabs(planes[i].dcc);
289 if ( adif < 0 ) tpars.tdir = 1;
291 tpars.heading = planes[i].ahdg;
292 message = current_transmissionlist->gen_text(station, code, tpars, true);
293 //cout << "Approach transmitting 3 ...\n";
294 //cout << message << '\n';
295 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
296 planes[i].lmc = code;
297 planes[i].tlm = etime_node->getDoubleValue();
300 planes[i].on_crs = false;
302 else if ( !planes[i].on_crs ) {
303 //cout << "Off course 2!\n";
304 wpn = planes[i].wpn-1;
305 adif = angle_diff_deg( planes[i].hdg, planes[i].wpts[wpn][4] )
306 * SGD_DEGREES_TO_RADIANS;
307 datp = 2*sin(fabs(adif)/2.0)*sin(fabs(adif)/2.0) *
308 planes[i].spd/3600. * planes[i].turn_rate +
309 planes[i].spd/3600. * 3.0;
310 if ( fabs(planes[i].dcc) < datp ) {
311 planes[i].ahdg = fabs(planes[i].wpts[wpn][4]);
313 // generate the message
317 tpars.station = name;
318 tpars.callsign = "Player";
319 if ( adif < 0 ) tpars.tdir = 1;
321 tpars.heading = planes[i].ahdg;
322 message = current_transmissionlist->gen_text(station, code, tpars, true);
323 //cout << "Approach transmitting 4 ...\n";
324 //cout << message << '\n';
325 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
326 planes[i].lmc = code;
327 planes[i].tlm = etime_node->getDoubleValue();
329 planes[i].on_crs = true;
332 else if ( planes[i].wp_change ) {
333 planes[i].wp_change = false;
336 // ===================================================================
337 // === Less than two minutes away from touchdown? -> Contact Tower ===
338 // ===================================================================
339 if ( planes[i].wpn == 2 && planes[i].dnwp < planes[i].spd/60.*2.0 ) {
341 double freq = 121.95; // Hardwired - FIXME
346 tpars.station = name;
347 tpars.callsign = "Player";
349 message = current_transmissionlist->gen_text(station, code, tpars, true);
350 //cout << "Approach transmitting 5 ...\n";
351 //cout << message << '\n';
352 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
353 planes[i].lmc = code;
354 planes[i].tlm = etime_node->getDoubleValue();
356 planes[i].contact = 2;
363 // ============================================================================
364 // update course parameters
365 // ============================================================================
366 void FGApproach::update_param( const int &i ) {
370 int wpn = planes[i].wpn-1; // this is the current waypoint
372 planes[i].dcc = calc_psl_dist(planes[i].brg, planes[i].dist,
373 planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
374 planes[i].wpts[wpn][4]);
375 planes[i].dnc = calc_psl_dist(planes[i].brg, planes[i].dist,
376 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
377 planes[i].wpts[wpn-1][4]);
378 calc_hd_course_dist(planes[i].brg, planes[i].dist,
379 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
385 // ============================================================================
386 // smallest difference between two angles in degree
387 // difference is negative if a1 > a2 and positive if a2 > a1
388 // ===========================================================================
389 double FGApproach::angle_diff_deg( const double &a1, const double &a2) {
392 if (a3 < 180.0) a3 += 360.0;
393 if (a3 > 180.0) a3 -= 360.0;
398 // ============================================================================
399 // calculate waypoints
400 // ============================================================================
401 void FGApproach::calc_wp( const int &i ) {
404 double course, d, cd, a1;
406 int wpn = planes[i].wpn;
407 // waypoint 0: Threshold of active runway
408 calc_gc_course_dist(Point3D(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0.0),
409 Point3D(active_rw_lon*SGD_DEGREES_TO_RADIANS,active_rw_lat*SGD_DEGREES_TO_RADIANS, 0.0 ),
411 double d1 = active_rw_hdg+180.0;
412 if ( d1 > 360.0 ) d1 -=360.0;
413 calc_cd_head_dist(360.0-course*SGD_RADIANS_TO_DEGREES, d/SG_NM_TO_METER,
414 d1, active_rw_len/SG_NM_TO_METER/2.0,
415 &planes[i].wpts[wpn][0], &planes[i].wpts[wpn][1]);
416 planes[i].wpts[wpn][2] = elev;
417 planes[i].wpts[wpn][4] = 0.0;
418 planes[i].wpts[wpn][5] = 0.0;
421 // ======================
422 // horizontal navigation
423 // ======================
424 // waypoint 1: point for turning onto final
425 calc_cd_head_dist(planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1], d1, lfl,
426 &planes[i].wpts[wpn][0], &planes[i].wpts[wpn][1]);
427 calc_hd_course_dist(planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
428 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
430 planes[i].wpts[wpn][4] = course;
431 planes[i].wpts[wpn][5] = d;
434 // calculate course and distance from plane position to waypoint 1
435 calc_hd_course_dist(planes[i].brg, planes[i].dist, planes[i].wpts[1][0],
436 planes[i].wpts[1][1], &course, &d);
437 // check if airport is not between plane and waypoint 1 and
438 // DCA to airport on course to waypoint 1 is larger than 10 miles
440 if ( fabs(angle_diff_deg( planes[i].wpts[1][0], planes[i].brg )) < 90.0 ||
441 calc_psl_dist( zero, zero, planes[i].brg, planes[i].dist, course ) > 10.0 ) {
442 // check if turning angle at waypoint 1 would be > max_ta
443 if ( fabs(angle_diff_deg( planes[i].wpts[1][4], course )) > max_ta ) {
444 cd = calc_psl_dist(planes[i].brg, planes[i].dist,
445 planes[i].wpts[1][0], planes[i].wpts[1][1],
446 planes[i].wpts[1][4]);
447 a1 = atan2(cd,planes[i].wpts[1][1]);
448 planes[i].wpts[wpn][0] = planes[i].wpts[1][0] - a1/SGD_DEGREES_TO_RADIANS;
449 if ( planes[i].wpts[wpn][0] < 0.0) planes[i].wpts[wpn][0] += 360.0;
450 if ( planes[i].wpts[wpn][0] > 360.0) planes[i].wpts[wpn][0] -= 360.0;
451 planes[i].wpts[wpn][1] = fabs(cd) / sin(fabs(a1));
452 calc_hd_course_dist(planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
453 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
455 planes[i].wpts[wpn][4] = course;
456 planes[i].wpts[wpn][5] = d;
459 calc_hd_course_dist(planes[i].brg, planes[i].dist, planes[i].wpts[wpn-1][0],
460 planes[i].wpts[wpn-1][1], &course, &d);
464 a1 = atan2(planes[i].wpts[1][1], leg );
466 if ( angle_diff_deg(planes[i].brg,planes[i].wpts[1][0]) < 0 )
467 planes[i].wpts[wpn][0] = planes[i].wpts[1][0] + a1/SGD_DEGREES_TO_RADIANS;
468 else planes[i].wpts[wpn][0] = planes[i].wpts[1][0] - a1/SGD_DEGREES_TO_RADIANS;
470 planes[i].wpts[wpn][1] = sqrt( planes[i].wpts[1][1]*planes[i].wpts[1][1] + leg*leg );
471 calc_hd_course_dist(planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
472 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
474 planes[i].wpts[wpn][4] = course;
475 planes[i].wpts[wpn][5] = d;
478 calc_hd_course_dist(planes[i].brg, planes[i].dist,
479 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
483 planes[i].wpts[wpn][0] = planes[i].brg;
484 planes[i].wpts[wpn][1] = planes[i].dist;
485 planes[i].wpts[wpn][2] = planes[i].alt;
486 planes[i].wpts[wpn][4] = course;
487 planes[i].wpts[wpn][5] = d;
492 // Now check if legs are too short or if legs can be shortend
493 // legs must be at least 2 flight minutes long
494 double mdist = planes[i].spd / 60.0 * 2.0;
495 for ( j=2; j<wpn-1; ++j ) {
496 if ( planes[i].wpts[j][1] < mdist) {
500 // ====================
501 // vertical navigation
502 // ====================
503 double alt = elev+3000.0;
504 planes[i].wpts[1][2] = round_alt( true, alt );
505 for ( j=2; j<wpn-1; ++j ) {
506 double dalt = planes[i].alt - planes[i].wpts[j-1][2];
508 alt = planes[i].wpts[j-1][2] +
509 (planes[i].wpts[j][5] / planes[i].spd) * 60.0 * planes[i].desc_rate;
510 planes[i].wpts[j][2] = round_alt( false, alt );
511 if ( planes[i].wpts[j][2] > planes[i].alt )
512 planes[i].wpts[j][2] = round_alt( false, planes[i].alt );
515 planes[i].wpts[j][2] = planes[i].wpts[1][2];
519 cout << "Plane position: " << planes[i].brg << " " << planes[i].dist << endl;
520 for ( j=0; j<wpn; ++j ) {
521 cout << "Waypoint " << j << endl;
522 cout << "------------------" << endl;
523 cout << planes[i].wpts[j][0] << " " << planes[i].wpts[j][1]
524 << " " << planes[i].wpts[j][2] << " " << planes[i].wpts[j][5];
525 cout << endl << endl;
531 // ============================================================================
532 // round altitude value to next highest/lowest 500 feet
533 // ============================================================================
534 double FGApproach::round_alt( const bool hl, double alt ) {
538 if ( alt > (int)(alt)+0.5 ) alt = ((int)(alt)+1)*1000.0;
539 else alt = ((int)(alt)+0.5)*1000.0;
542 if ( alt > (int)(alt)+0.5 ) alt = ((int)(alt)+0.5)*1000.0;
543 else alt = ((int)(alt))*1000.0;
550 // ============================================================================
552 // ============================================================================
553 void FGApproach::get_active_runway() {
554 //cout << "Entering FGApproach::get_active_runway()\n";
557 sgVec3 position = { lat, lon, elev };
558 FGPhysicalProperty stationweather = WeatherDatabase->get(position);
560 FGEnvironment stationweather =
561 ((FGEnvironmentMgr *)globals->get_subsystem("environment"))
562 ->getEnvironment(lat, lon, elev);
566 //Set the heading to into the wind
567 double wind_x = stationweather.Wind[0];
568 double wind_y = stationweather.Wind[1];
570 double speed = sqrt( wind_x*wind_x + wind_y*wind_y ) * SG_METER_TO_NM / (60.0*60.0);
573 //If no wind use 270degrees
577 // //normalize the wind to get the direction
578 //wind_x /= speed; wind_y /= speed;
580 hdg = - atan2 ( wind_x, wind_y ) * SG_RADIANS_TO_DEGREES ;
585 double hdg = stationweather.get_wind_from_heading_deg();
589 if ( globals->get_runways()->search( ident, int(hdg), &runway) ) {
590 active_runway = runway.rwy_no;
591 active_rw_hdg = runway.heading;
592 active_rw_lon = runway.lon;
593 active_rw_lat = runway.lat;
594 active_rw_len = runway.length;
595 //cout << "Active runway is: " << active_runway << " heading = "
597 // << " lon = " << active_rw_lon
598 // << " lat = " << active_rw_lat <<endl;
600 else cout << "FGRunways search failed\n";
604 // ========================================================================
605 // update infos about plane
606 // ========================================================================
607 void FGApproach::update_plane_dat() {
609 //cout << "Update Approach " << ident << " " << num_planes << " registered" << endl;
610 // update plane positions
612 for (i=0; i<num_planes; i++) {
613 planes[i].lon = lon_node->getDoubleValue();
614 planes[i].lat = lat_node->getDoubleValue();
615 planes[i].alt = elev_node->getDoubleValue();
616 planes[i].hdg = hdg_node->getDoubleValue();
617 planes[i].spd = speed_node->getDoubleValue();
619 /*Point3D aircraft = sgGeodToCart( Point3D(planes[i].lon*SGD_DEGREES_TO_RADIANS,
620 planes[i].lat*SGD_DEGREES_TO_RADIANS,
621 planes[i].alt*SG_FEET_TO_METER) );*/
622 double course, distance;
623 calc_gc_course_dist(Point3D(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0.0),
624 Point3D(planes[i].lon*SGD_DEGREES_TO_RADIANS,planes[i].lat*SGD_DEGREES_TO_RADIANS, 0.0 ),
626 planes[i].dist = distance/SG_NM_TO_METER;
627 planes[i].brg = 360.0-course*SGD_RADIANS_TO_DEGREES;
629 //cout << "Plane Id: " << planes[i].ident << " Distance to " << ident
630 // << " is " << planes[i].dist << " miles " << "Bearing " << planes[i].brg << endl;
635 // =======================================================================
636 // Add plane to Approach list
637 // =======================================================================
638 void FGApproach::AddPlane(string pid) {
641 for ( i=0; i<num_planes; i++) {
642 if ( planes[i].ident == pid) {
643 //cout << "Plane already registered: " << planes[i].ident << ' ' << ident << ' ' << num_planes << endl;
647 planes[num_planes].ident = pid;
649 //cout << "Plane added to list: " << ident << " " << num_planes << endl;
653 // ================================================================================
654 // closest distance between a point (h1,d1) and a straigt line (h2,d2,h3) in 2 dim.
655 // ================================================================================
656 double FGApproach::calc_psl_dist(const double &h1, const double &d1,
657 const double &h2, const double &d2,
660 double a1 = h1 * SGD_DEGREES_TO_RADIANS;
661 double a2 = h2 * SGD_DEGREES_TO_RADIANS;
662 double a3 = h3 * SGD_DEGREES_TO_RADIANS;
663 double x1 = cos(a1) * d1;
664 double y1 = sin(a1) * d1;
665 double x2 = cos(a2) * d2;
666 double y2 = sin(a2) * d2;
670 // formula: dis = sqrt( (v1-v2)**2 - ((v1-v2)*v3)**2 ); vi = (xi,yi)
671 double val1 = (x1-x2)*(x1-x2) + (y1-y2)*(y1-y2);
672 double val2 = ((x1-x2)*x3 + (y1-y2)*y3) * ((x1-x2)*x3 + (y1-y2)*y3);
673 double dis = val1 - val2;
674 // now get sign for offset
675 //cout << x1 << " " << x2 << " " << y1 << " " << y2 << " "
676 // << x3 << " " << y3 << " "
677 // << val1 << " " << val2 << " " << dis << endl;
680 double da = fabs(atan2(y3,x3) - atan2(y1-y2,x1-x2));
681 if ( da > SGD_PI ) da -= 2*SGD_PI;
682 if ( fabs(da) > SGD_PI/2.) {
683 //if ( x3*(x1-x2) < 0.0 && y3*(y1-y2) < 0.0) {
687 //cout << x3 << " " << y3 << endl;
688 double dis1 = x1-x2-x3;
689 double dis2 = y1-y2-y3;
691 da = atan2(dis2,dis1);
692 if ( da < 0.0 ) da += 2*SGD_PI;
693 if ( da < a3 ) dis *= -1.0;
694 //cout << dis1 << " " << dis2 << " " << da*SGD_RADIANS_TO_DEGREES << " " << h3
695 // << " " << sqrt(dis1*dis1 + dis2*dis2) << " " << dis << endl;
696 //cout << atan2(dis2,dis1)*SGD_RADIANS_TO_DEGREES << " " << dis << endl;
702 // ========================================================================
703 // Calculate new bear/dist given starting bear/dis, and offset radial,
705 // ========================================================================
706 void FGApproach::calc_cd_head_dist(const double &h1, const double &d1,
707 const double &course, const double &dist,
708 double *h2, double *d2)
710 double a1 = h1 * SGD_DEGREES_TO_RADIANS;
711 double a2 = course * SGD_DEGREES_TO_RADIANS;
712 double x1 = cos(a1) * d1;
713 double y1 = sin(a1) * d1;
714 double x2 = cos(a2) * dist;
715 double y2 = sin(a2) * dist;
717 *d2 = sqrt((x1+x2)*(x1+x2) + (y1+y2)*(y1+y2));
718 *h2 = atan2( (y1+y2), (x1+x2) ) * SGD_RADIANS_TO_DEGREES;
719 if ( *h2 < 0 ) *h2 = *h2+360;
724 // ========================================================================
725 // get heading and distance between two points; point1 ---> point2
726 // ========================================================================
727 void FGApproach::calc_hd_course_dist(const double &h1, const double &d1,
728 const double &h2, const double &d2,
729 double *course, double *dist)
731 double a1 = h1 * SGD_DEGREES_TO_RADIANS;
732 double a2 = h2 * SGD_DEGREES_TO_RADIANS;
733 double x1 = cos(a1) * d1;
734 double y1 = sin(a1) * d1;
735 double x2 = cos(a2) * d2;
736 double y2 = sin(a2) * d2;
738 *dist = sqrt( (y2-y1)*(y2-y1) + (x2-x1)*(x2-x1) );
739 *course = atan2( (y2-y1), (x2-x1) ) * SGD_RADIANS_TO_DEGREES;
740 if ( *course < 0 ) *course = *course+360;
741 //cout << x1 << " " << y1 << " " << x2 << " " << y2 << " " << *dist << " " << *course << endl;
746 int FGApproach::RemovePlane() {
748 // first check if anything has to be done
749 bool rmplane = false;
752 for (i=0; i<num_planes; i++) {
753 if (planes[i].dist > range*SG_NM_TO_METER) {
758 if (!rmplane) return num_planes;
760 // now make a copy of the plane list
761 PlaneApp tmp[max_planes];
762 for (i=0; i<num_planes; i++) {
767 // now check which planes are still in range
768 for (i=0; i<num_planes; i++) {
769 if (tmp[i].dist <= range*SG_NM_TO_METER) {