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/math/polar3d.hxx>
29 #include <simgear/misc/sg_path.hxx>
32 # include <WeatherCM/FGLocalWeatherDatabase.h>
34 # include <Environment/environment_mgr.hxx>
35 # include <Environment/environment.hxx>
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);
47 lon_node = fgGetNode("/position/longitude-deg", true);
48 lat_node = fgGetNode("/position/latitude-deg", true);
49 elev_node = fgGetNode("/position/altitude-ft", true);
50 hdg_node = fgGetNode("/orientation/heading-deg", true);
51 speed_node = fgGetNode("/velocities/airspeed-kt", true);
52 etime_node = fgGetNode("/sim/time/elapsed-ms", true);
57 for ( i=0; i<max_planes; i++) {
58 planes[i].contact = 0;
60 planes[i].dnwp = -999.;
61 planes[i].on_crs = true;
62 planes[i].turn_rate = 10.0;
63 planes[i].desc_rate = 1000.0;
64 planes[i].clmb_rate = 500.0;
68 planes[i].lmc.c3 = -1;
69 planes[i].wp_change = false;
74 FGApproach::~FGApproach(){
77 void FGApproach::Init() {
83 // ============================================================================
84 // the main update function
85 // ============================================================================
86 void FGApproach::Update(double dt) {
88 const int max_trans = 20;
89 FGTransmission tmissions[max_trans];
91 atc_type station = APPROACH;
99 //static string atcmsg1[10];
100 //static string atcmsg2[10];
104 //static bool TransDisplayed = false;
107 if ( active_runway == "" ) get_active_runway();
109 double comm1_freq = comm1_node->getDoubleValue();
111 //bool DisplayTransmissions = true;
113 for (i=0; i<num_planes; i++) {
114 if ( planes[i].ident == "Player") {
116 tpars.station = name;
117 tpars.callsign = "Player";
118 tpars.airport = ident;
120 //cout << "ident = " << ident << " name = " << name << '\n';
123 // is the frequency of the station tuned in?
124 if ( freq == (int)(comm1_freq*100.0 + 0.5) ) {
125 current_transmissionlist->query_station( station, tmissions, max_trans, num_trans );
126 // loop over all transmissions for station
127 for ( j=0; j<=num_trans-1; j++ ) {
128 code = tmissions[j].get_code();
129 //cout << "code is " << code.c1 << " " << code.c2 << " " << code.c3 << '\n';
130 // select proper transmissions
131 if(code.c3 != 2) { // DCL - hack to prevent request crossing airspace being displayed since this isn't implemented yet.
132 if ( ( code.c2 == -1 && planes[i].lmc.c3 == 0 ) ||
133 ( code.c1 == 0 && code.c2 == planes[i].lmc.c2 ) ) {
134 mentry = current_transmissionlist->gen_text(station, code, tpars, false);
135 transm = current_transmissionlist->gen_text(station, code, tpars, true);
136 // is the transmission already registered?
137 if (!current_atcdialog->trans_reg( ident, transm, APPROACH )) {
138 current_atcdialog->add_entry( ident, transm, mentry, APPROACH, 0 );
147 for ( i=0; i<num_planes; i++ ) {
148 //cout << "TPar.airport = " << TPar.airport << " TPar.station = " << TPar.station << " TPar.callsign = " << TPar.callsign << '\n';
149 //if ( planes[i].ident == TPar.callsign && name == TPar.airport && TPar.station == "approach" ) {
150 //if ( TPar.request && TPar.intention == "landing" && ident == TPar.intid) {
151 if(planes[i].ident == "Player" && fgGetBool("/sim/atc/opt0")) {
152 //cout << "Landing requested\n";
153 fgSetBool("/sim/atc/opt0", false);
155 // ===========================
156 // === calculate waypoints ===
157 // ===========================
160 wpn = planes[i].wpn-1;
161 planes[i].aalt = planes[i].wpts[wpn-1][2];
162 planes[i].ahdg = planes[i].wpts[wpn][4];
164 // generate the message
168 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
169 tpars.station = name;
170 tpars.callsign = "Player";
171 if ( adif < 0 ) tpars.tdir = 1;
173 tpars.heading = planes[i].ahdg;
174 if (planes[i].alt-planes[i].aalt > 100.0) tpars.VDir = 1;
175 else if (planes[i].alt-planes[i].aalt < -100.0) tpars.VDir = 3;
177 tpars.alt = planes[i].aalt;
178 message = current_transmissionlist->gen_text(station, code, tpars, true );
179 //cout << message << '\n';
180 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
181 planes[i].lmc = code;
182 planes[i].tlm = etime_node->getDoubleValue();
183 planes[i].on_crs = true;
184 planes[i].contact = 1;
189 if ( planes[i].contact == 1 ) {
190 // =========================
191 // === update parameters ===
192 // =========================
194 //cout << planes[i].brg << " " << planes[i].dist << " " << planes[i].wpts[wpn+1][0]
195 //<< " " << planes[i].wpts[wpn+1][1] << " " << planes[i].wpts[wpn+1][4]
196 //cout << wpn << " distance to current course = " << planes[i].dcc << endl;
197 //cout << etime_node->getDoubleValue() << endl;
199 // =========================
200 // === reached waypoint? ===
201 // =========================
202 wpn = planes[i].wpn-2;
203 adif = angle_diff_deg( planes[i].hdg, planes[i].wpts[wpn][4] )
204 * SGD_DEGREES_TO_RADIANS;
205 datp = 2*sin(fabs(adif)/2.0)*sin(fabs(adif)/2.0) *
206 planes[i].spd/3600. * planes[i].turn_rate +
207 planes[i].spd/3600. * 3.0;
208 //cout << adif/SGD_DEGREES_TO_RADIANS << " "
209 // << datp << " " << planes[i].dnc << " " << planes[i].dcc <<endl;
210 if ( fabs(planes[i].dnc) < datp ) {
211 //if ( fabs(planes[i].dnc) < 0.3 && planes[i].dnwp < 1.0 ) {
212 //cout << "Reached next waypoint!\n";
214 wpn = planes[i].wpn-1;
215 planes[i].ahdg = planes[i].wpts[wpn][4];
216 planes[i].aalt = planes[i].wpts[wpn-1][2];
217 planes[i].wp_change = true;
219 // generate the message
220 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
221 tpars.station = name;
222 tpars.callsign = "Player";
223 if ( adif < 0 ) tpars.tdir = 1;
225 tpars.heading = planes[i].ahdg;
231 if (planes[i].alt-planes[i].aalt > 100.0) tpars.VDir = 1;
232 else if (planes[i].alt-planes[i].aalt < -100.0) tpars.VDir = 3;
234 tpars.alt = planes[i].aalt;
235 message = current_transmissionlist->gen_text(station, code, tpars, true );
236 //cout << "Approach transmitting...\n";
237 //cout << message << endl;
238 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
245 tpars.runway = active_runway;
246 message = current_transmissionlist->gen_text(station, code, tpars, true);
247 //cout << "Approach transmitting 2 ...\n";
248 //cout << message << endl;
249 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
251 planes[i].lmc = code;
252 planes[i].tlm = etime_node->getDoubleValue();
253 planes[i].on_crs = true;
258 // =========================
259 // === come off course ? ===
260 // =========================
261 if ( fabs(planes[i].dcc) > 1.0 &&
262 ( !planes[i].wp_change || etime_node->getDoubleValue() - planes[i].tlm > tbm ) ) {
263 //cout << "Off course!\n";
264 if ( planes[i].on_crs ) {
265 if ( planes[i].dcc < 0) {
266 planes[i].ahdg += 30.0;
269 planes[i].ahdg -= 30.0;
271 if (planes[i].ahdg > 360.0) planes[i].ahdg -= 360.0;
272 else if (planes[i].ahdg < 0.0) planes[i].ahdg += 360.0;
274 //cout << planes[i].on_crs << " "
275 // << angle_diff_deg( planes[i].hdg, planes[i].ahdg) << " "
276 // << etime_node->getDoubleValue() << " "
277 // << planes[i].tlm << endl;
278 // generate the message
279 if ( planes[i].on_crs ||
280 ( fabs(angle_diff_deg( planes[i].hdg, planes[i].ahdg )) > 30.0 &&
281 etime_node->getDoubleValue() - planes[i].tlm > tbm) ) {
282 // generate the message
286 adif = angle_diff_deg( planes[i].hdg, planes[i].ahdg );
287 tpars.station = name;
288 tpars.callsign = "Player";
289 tpars.miles = fabs(planes[i].dcc);
290 if ( adif < 0 ) tpars.tdir = 1;
292 tpars.heading = planes[i].ahdg;
293 message = current_transmissionlist->gen_text(station, code, tpars, true);
294 //cout << "Approach transmitting 3 ...\n";
295 //cout << message << '\n';
296 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
297 planes[i].lmc = code;
298 planes[i].tlm = etime_node->getDoubleValue();
301 planes[i].on_crs = false;
303 else if ( !planes[i].on_crs ) {
304 //cout << "Off course 2!\n";
305 wpn = planes[i].wpn-1;
306 adif = angle_diff_deg( planes[i].hdg, planes[i].wpts[wpn][4] )
307 * SGD_DEGREES_TO_RADIANS;
308 datp = 2*sin(fabs(adif)/2.0)*sin(fabs(adif)/2.0) *
309 planes[i].spd/3600. * planes[i].turn_rate +
310 planes[i].spd/3600. * 3.0;
311 if ( fabs(planes[i].dcc) < datp ) {
312 planes[i].ahdg = fabs(planes[i].wpts[wpn][4]);
314 // generate the message
318 tpars.station = name;
319 tpars.callsign = "Player";
320 if ( adif < 0 ) tpars.tdir = 1;
322 tpars.heading = planes[i].ahdg;
323 message = current_transmissionlist->gen_text(station, code, tpars, true);
324 //cout << "Approach transmitting 4 ...\n";
325 //cout << message << '\n';
326 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
327 planes[i].lmc = code;
328 planes[i].tlm = etime_node->getDoubleValue();
330 planes[i].on_crs = true;
333 else if ( planes[i].wp_change ) {
334 planes[i].wp_change = false;
337 // ===================================================================
338 // === Less than two minutes away from touchdown? -> Contact Tower ===
339 // ===================================================================
340 if ( planes[i].wpn == 2 && planes[i].dnwp < planes[i].spd/60.*2.0 ) {
342 double freq = 121.95; // Hardwired - FIXME
347 tpars.station = name;
348 tpars.callsign = "Player";
350 message = current_transmissionlist->gen_text(station, code, tpars, true);
351 //cout << "Approach transmitting 5 ...\n";
352 //cout << message << '\n';
353 globals->get_ATC_display()->RegisterSingleMessage( message, 0 );
354 planes[i].lmc = code;
355 planes[i].tlm = etime_node->getDoubleValue();
357 planes[i].contact = 2;
364 // ============================================================================
365 // update course parameters
366 // ============================================================================
367 void FGApproach::update_param( const int &i ) {
371 int wpn = planes[i].wpn-1; // this is the current waypoint
373 planes[i].dcc = calc_psl_dist(planes[i].brg, planes[i].dist,
374 planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
375 planes[i].wpts[wpn][4]);
376 planes[i].dnc = calc_psl_dist(planes[i].brg, planes[i].dist,
377 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
378 planes[i].wpts[wpn-1][4]);
379 calc_hd_course_dist(planes[i].brg, planes[i].dist,
380 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
386 // ============================================================================
387 // smallest difference between two angles in degree
388 // difference is negative if a1 > a2 and positive if a2 > a1
389 // ===========================================================================
390 double FGApproach::angle_diff_deg( const double &a1, const double &a2) {
393 if (a3 < 180.0) a3 += 360.0;
394 if (a3 > 180.0) a3 -= 360.0;
399 // ============================================================================
400 // calculate waypoints
401 // ============================================================================
402 void FGApproach::calc_wp( const int &i ) {
405 double course, d, cd, a1;
407 int wpn = planes[i].wpn;
408 // waypoint 0: Threshold of active runway
409 calc_gc_course_dist(Point3D(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0.0),
410 Point3D(active_rw_lon*SGD_DEGREES_TO_RADIANS,active_rw_lat*SGD_DEGREES_TO_RADIANS, 0.0 ),
412 double d1 = active_rw_hdg+180.0;
413 if ( d1 > 360.0 ) d1 -=360.0;
414 calc_cd_head_dist(360.0-course*SGD_RADIANS_TO_DEGREES, d/SG_NM_TO_METER,
415 d1, active_rw_len/SG_NM_TO_METER/2.0,
416 &planes[i].wpts[wpn][0], &planes[i].wpts[wpn][1]);
417 planes[i].wpts[wpn][2] = elev;
418 planes[i].wpts[wpn][4] = 0.0;
419 planes[i].wpts[wpn][5] = 0.0;
422 // ======================
423 // horizontal navigation
424 // ======================
425 // waypoint 1: point for turning onto final
426 calc_cd_head_dist(planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1], d1, lfl,
427 &planes[i].wpts[wpn][0], &planes[i].wpts[wpn][1]);
428 calc_hd_course_dist(planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
429 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
431 planes[i].wpts[wpn][4] = course;
432 planes[i].wpts[wpn][5] = d;
435 // calculate course and distance from plane position to waypoint 1
436 calc_hd_course_dist(planes[i].brg, planes[i].dist, planes[i].wpts[1][0],
437 planes[i].wpts[1][1], &course, &d);
438 // check if airport is not between plane and waypoint 1 and
439 // DCA to airport on course to waypoint 1 is larger than 10 miles
441 if ( fabs(angle_diff_deg( planes[i].wpts[1][0], planes[i].brg )) < 90.0 ||
442 calc_psl_dist( zero, zero, planes[i].brg, planes[i].dist, course ) > 10.0 ) {
443 // check if turning angle at waypoint 1 would be > max_ta
444 if ( fabs(angle_diff_deg( planes[i].wpts[1][4], course )) > max_ta ) {
445 cd = calc_psl_dist(planes[i].brg, planes[i].dist,
446 planes[i].wpts[1][0], planes[i].wpts[1][1],
447 planes[i].wpts[1][4]);
448 a1 = atan2(cd,planes[i].wpts[1][1]);
449 planes[i].wpts[wpn][0] = planes[i].wpts[1][0] - a1/SGD_DEGREES_TO_RADIANS;
450 if ( planes[i].wpts[wpn][0] < 0.0) planes[i].wpts[wpn][0] += 360.0;
451 if ( planes[i].wpts[wpn][0] > 360.0) planes[i].wpts[wpn][0] -= 360.0;
452 planes[i].wpts[wpn][1] = fabs(cd) / sin(fabs(a1));
453 calc_hd_course_dist(planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
454 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
456 planes[i].wpts[wpn][4] = course;
457 planes[i].wpts[wpn][5] = d;
460 calc_hd_course_dist(planes[i].brg, planes[i].dist, planes[i].wpts[wpn-1][0],
461 planes[i].wpts[wpn-1][1], &course, &d);
465 a1 = atan2(planes[i].wpts[1][1], leg );
467 if ( angle_diff_deg(planes[i].brg,planes[i].wpts[1][0]) < 0 )
468 planes[i].wpts[wpn][0] = planes[i].wpts[1][0] + a1/SGD_DEGREES_TO_RADIANS;
469 else planes[i].wpts[wpn][0] = planes[i].wpts[1][0] - a1/SGD_DEGREES_TO_RADIANS;
471 planes[i].wpts[wpn][1] = sqrt( planes[i].wpts[1][1]*planes[i].wpts[1][1] + leg*leg );
472 calc_hd_course_dist(planes[i].wpts[wpn][0], planes[i].wpts[wpn][1],
473 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
475 planes[i].wpts[wpn][4] = course;
476 planes[i].wpts[wpn][5] = d;
479 calc_hd_course_dist(planes[i].brg, planes[i].dist,
480 planes[i].wpts[wpn-1][0], planes[i].wpts[wpn-1][1],
484 planes[i].wpts[wpn][0] = planes[i].brg;
485 planes[i].wpts[wpn][1] = planes[i].dist;
486 planes[i].wpts[wpn][2] = planes[i].alt;
487 planes[i].wpts[wpn][4] = course;
488 planes[i].wpts[wpn][5] = d;
493 // Now check if legs are too short or if legs can be shortend
494 // legs must be at least 2 flight minutes long
495 double mdist = planes[i].spd / 60.0 * 2.0;
496 for ( j=2; j<wpn-1; ++j ) {
497 if ( planes[i].wpts[j][1] < mdist) {
501 // ====================
502 // vertical navigation
503 // ====================
504 double alt = elev+3000.0;
505 planes[i].wpts[1][2] = round_alt( true, alt );
506 for ( j=2; j<wpn-1; ++j ) {
507 double dalt = planes[i].alt - planes[i].wpts[j-1][2];
509 alt = planes[i].wpts[j-1][2] +
510 (planes[i].wpts[j][5] / planes[i].spd) * 60.0 * planes[i].desc_rate;
511 planes[i].wpts[j][2] = round_alt( false, alt );
512 if ( planes[i].wpts[j][2] > planes[i].alt )
513 planes[i].wpts[j][2] = round_alt( false, planes[i].alt );
516 planes[i].wpts[j][2] = planes[i].wpts[1][2];
520 cout << "Plane position: " << planes[i].brg << " " << planes[i].dist << endl;
521 for ( j=0; j<wpn; ++j ) {
522 cout << "Waypoint " << j << endl;
523 cout << "------------------" << endl;
524 cout << planes[i].wpts[j][0] << " " << planes[i].wpts[j][1]
525 << " " << planes[i].wpts[j][2] << " " << planes[i].wpts[j][5];
526 cout << endl << endl;
532 // ============================================================================
533 // round altitude value to next highest/lowest 500 feet
534 // ============================================================================
535 double FGApproach::round_alt( const bool hl, double alt ) {
539 if ( alt > (int)(alt)+0.5 ) alt = ((int)(alt)+1)*1000.0;
540 else alt = ((int)(alt)+0.5)*1000.0;
543 if ( alt > (int)(alt)+0.5 ) alt = ((int)(alt)+0.5)*1000.0;
544 else alt = ((int)(alt))*1000.0;
551 // ============================================================================
553 // ============================================================================
554 void FGApproach::get_active_runway() {
555 //cout << "Entering FGApproach::get_active_runway()\n";
558 sgVec3 position = { lat, lon, elev };
559 FGPhysicalProperty stationweather = WeatherDatabase->get(position);
561 FGEnvironment stationweather =
562 ((FGEnvironmentMgr *)globals->get_subsystem("environment"))
563 ->getEnvironment(lat, lon, elev);
567 //Set the heading to into the wind
568 double wind_x = stationweather.Wind[0];
569 double wind_y = stationweather.Wind[1];
571 double speed = sqrt( wind_x*wind_x + wind_y*wind_y ) * SG_METER_TO_NM / (60.0*60.0);
574 //If no wind use 270degrees
578 // //normalize the wind to get the direction
579 //wind_x /= speed; wind_y /= speed;
581 hdg = - atan2 ( wind_x, wind_y ) * SG_RADIANS_TO_DEGREES ;
586 double hdg = stationweather.get_wind_from_heading_deg();
590 if ( globals->get_runways()->search( ident, int(hdg), &runway) ) {
591 active_runway = runway.rwy_no;
592 active_rw_hdg = runway.heading;
593 active_rw_lon = runway.lon;
594 active_rw_lat = runway.lat;
595 active_rw_len = runway.length;
596 //cout << "Active runway is: " << active_runway << " heading = "
598 // << " lon = " << active_rw_lon
599 // << " lat = " << active_rw_lat <<endl;
601 else cout << "FGRunways search failed\n";
605 // ========================================================================
606 // update infos about plane
607 // ========================================================================
608 void FGApproach::update_plane_dat() {
610 //cout << "Update Approach " << ident << " " << num_planes << " registered" << endl;
611 // update plane positions
613 for (i=0; i<num_planes; i++) {
614 planes[i].lon = lon_node->getDoubleValue();
615 planes[i].lat = lat_node->getDoubleValue();
616 planes[i].alt = elev_node->getDoubleValue();
617 planes[i].hdg = hdg_node->getDoubleValue();
618 planes[i].spd = speed_node->getDoubleValue();
620 /*Point3D aircraft = sgGeodToCart( Point3D(planes[i].lon*SGD_DEGREES_TO_RADIANS,
621 planes[i].lat*SGD_DEGREES_TO_RADIANS,
622 planes[i].alt*SG_FEET_TO_METER) );*/
623 double course, distance;
624 calc_gc_course_dist(Point3D(lon*SGD_DEGREES_TO_RADIANS, lat*SGD_DEGREES_TO_RADIANS, 0.0),
625 Point3D(planes[i].lon*SGD_DEGREES_TO_RADIANS,planes[i].lat*SGD_DEGREES_TO_RADIANS, 0.0 ),
627 planes[i].dist = distance/SG_NM_TO_METER;
628 planes[i].brg = 360.0-course*SGD_RADIANS_TO_DEGREES;
630 //cout << "Plane Id: " << planes[i].ident << " Distance to " << ident
631 // << " is " << planes[i].dist << " miles " << "Bearing " << planes[i].brg << endl;
636 // =======================================================================
637 // Add plane to Approach list
638 // =======================================================================
639 void FGApproach::AddPlane(string pid) {
642 for ( i=0; i<num_planes; i++) {
643 if ( planes[i].ident == pid) {
644 //cout << "Plane already registered: " << planes[i].ident << ' ' << ident << ' ' << num_planes << endl;
648 planes[num_planes].ident = pid;
650 //cout << "Plane added to list: " << ident << " " << num_planes << endl;
654 // ================================================================================
655 // closest distance between a point (h1,d1) and a straigt line (h2,d2,h3) in 2 dim.
656 // ================================================================================
657 double FGApproach::calc_psl_dist(const double &h1, const double &d1,
658 const double &h2, const double &d2,
661 double a1 = h1 * SGD_DEGREES_TO_RADIANS;
662 double a2 = h2 * SGD_DEGREES_TO_RADIANS;
663 double a3 = h3 * SGD_DEGREES_TO_RADIANS;
664 double x1 = cos(a1) * d1;
665 double y1 = sin(a1) * d1;
666 double x2 = cos(a2) * d2;
667 double y2 = sin(a2) * d2;
671 // formula: dis = sqrt( (v1-v2)**2 - ((v1-v2)*v3)**2 ); vi = (xi,yi)
672 double val1 = (x1-x2)*(x1-x2) + (y1-y2)*(y1-y2);
673 double val2 = ((x1-x2)*x3 + (y1-y2)*y3) * ((x1-x2)*x3 + (y1-y2)*y3);
674 double dis = val1 - val2;
675 // now get sign for offset
676 //cout << x1 << " " << x2 << " " << y1 << " " << y2 << " "
677 // << x3 << " " << y3 << " "
678 // << val1 << " " << val2 << " " << dis << endl;
681 double da = fabs(atan2(y3,x3) - atan2(y1-y2,x1-x2));
682 if ( da > SGD_PI ) da -= 2*SGD_PI;
683 if ( fabs(da) > SGD_PI/2.) {
684 //if ( x3*(x1-x2) < 0.0 && y3*(y1-y2) < 0.0) {
688 //cout << x3 << " " << y3 << endl;
689 double dis1 = x1-x2-x3;
690 double dis2 = y1-y2-y3;
692 da = atan2(dis2,dis1);
693 if ( da < 0.0 ) da += 2*SGD_PI;
694 if ( da < a3 ) dis *= -1.0;
695 //cout << dis1 << " " << dis2 << " " << da*SGD_RADIANS_TO_DEGREES << " " << h3
696 // << " " << sqrt(dis1*dis1 + dis2*dis2) << " " << dis << endl;
697 //cout << atan2(dis2,dis1)*SGD_RADIANS_TO_DEGREES << " " << dis << endl;
703 // ========================================================================
704 // Calculate new bear/dist given starting bear/dis, and offset radial,
706 // ========================================================================
707 void FGApproach::calc_cd_head_dist(const double &h1, const double &d1,
708 const double &course, const double &dist,
709 double *h2, double *d2)
711 double a1 = h1 * SGD_DEGREES_TO_RADIANS;
712 double a2 = course * SGD_DEGREES_TO_RADIANS;
713 double x1 = cos(a1) * d1;
714 double y1 = sin(a1) * d1;
715 double x2 = cos(a2) * dist;
716 double y2 = sin(a2) * dist;
718 *d2 = sqrt((x1+x2)*(x1+x2) + (y1+y2)*(y1+y2));
719 *h2 = atan2( (y1+y2), (x1+x2) ) * SGD_RADIANS_TO_DEGREES;
720 if ( *h2 < 0 ) *h2 = *h2+360;
725 // ========================================================================
726 // get heading and distance between two points; point1 ---> point2
727 // ========================================================================
728 void FGApproach::calc_hd_course_dist(const double &h1, const double &d1,
729 const double &h2, const double &d2,
730 double *course, double *dist)
732 double a1 = h1 * SGD_DEGREES_TO_RADIANS;
733 double a2 = h2 * SGD_DEGREES_TO_RADIANS;
734 double x1 = cos(a1) * d1;
735 double y1 = sin(a1) * d1;
736 double x2 = cos(a2) * d2;
737 double y2 = sin(a2) * d2;
739 *dist = sqrt( (y2-y1)*(y2-y1) + (x2-x1)*(x2-x1) );
740 *course = atan2( (y2-y1), (x2-x1) ) * SGD_RADIANS_TO_DEGREES;
741 if ( *course < 0 ) *course = *course+360;
742 //cout << x1 << " " << y1 << " " << x2 << " " << y2 << " " << *dist << " " << *course << endl;
747 int FGApproach::RemovePlane() {
749 // first check if anything has to be done
750 bool rmplane = false;
753 for (i=0; i<num_planes; i++) {
754 if (planes[i].dist > range*SG_NM_TO_METER) {
759 if (!rmplane) return num_planes;
761 // now make a copy of the plane list
762 PlaneApp tmp[max_planes];
763 for (i=0; i<num_planes; i++) {
768 // now check which planes are still in range
769 for (i=0; i<num_planes; i++) {
770 if (tmp[i].dist <= range*SG_NM_TO_METER) {