1 // marker_beacon.cxx -- class to manage the marker beacons
3 // Written by Curtis Olson, started April 2000.
5 // Copyright (C) 2000 Curtis L. Olson - http://www.flightgear.org/~curt
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.
28 #include <stdio.h> // snprintf
30 #include <simgear/compiler.h>
31 #include <simgear/math/sg_random.h>
33 #include <Aircraft/aircraft.hxx>
34 #include <Navaids/navlist.hxx>
36 #include "marker_beacon.hxx"
43 FGMarkerBeacon::FGMarkerBeacon(SGPropertyNode *node) :
48 name("marker-beacon"),
51 SGPath path( globals->get_fg_root() );
53 term.append( "Navaids/range.term" );
55 low.append( "Navaids/range.low" );
57 high.append( "Navaids/range.high" );
59 term_tbl = new SGInterpTable( term.str() );
60 low_tbl = new SGInterpTable( low.str() );
61 high_tbl = new SGInterpTable( high.str() );
64 for ( i = 0; i < node->nChildren(); ++i ) {
65 SGPropertyNode *child = node->getChild(i);
66 string cname = child->getName();
67 string cval = child->getStringValue();
68 if ( cname == "name" ) {
70 } else if ( cname == "number" ) {
71 num = child->getIntValue();
73 SG_LOG( SG_INSTR, SG_WARN,
74 "Error in marker beacon config logic" );
75 if ( name.length() ) {
76 SG_LOG( SG_INSTR, SG_WARN, "Section = " << name );
84 FGMarkerBeacon::~FGMarkerBeacon()
93 FGMarkerBeacon::init ()
96 branch = "/instrumentation/" + name;
98 SGPropertyNode *node = fgGetNode(branch.c_str(), num, true );
100 lon_node = fgGetNode("/position/longitude-deg", true);
101 lat_node = fgGetNode("/position/latitude-deg", true);
102 alt_node = fgGetNode("/position/altitude-ft", true);
103 bus_power = fgGetNode("/systems/electrical/outputs/navcom[0]", true);
104 power_btn = node->getChild("power-btn", 0, true);
105 audio_btn = node->getChild("audio-btn", 0, true);
106 serviceable = node->getChild("serviceable", 0, true);
108 power_btn->setBoolValue( true );
109 audio_btn->setBoolValue( true );
110 serviceable->setBoolValue( true );
119 FGMarkerBeacon::bind ()
122 branch = "/instrumentation/" + name;
124 fgTie((branch + "/inner").c_str(), this,
125 &FGMarkerBeacon::get_inner_blink);
127 fgTie((branch + "/middle").c_str(), this,
128 &FGMarkerBeacon::get_middle_blink);
130 fgTie((branch + "/outer").c_str(), this,
131 &FGMarkerBeacon::get_outer_blink);
136 FGMarkerBeacon::unbind ()
139 branch = "/instrumentation/" + name;
141 fgUntie((branch + "/inner").c_str());
142 fgUntie((branch + "/middle").c_str());
143 fgUntie((branch + "/outer").c_str());
147 // Update the various nav values based on position and valid tuned in navs
149 FGMarkerBeacon::update(double dt)
153 if ( has_power() && serviceable->getBoolValue() ) {
155 // On timeout, scan again
156 _time_before_search_sec -= dt;
157 if ( _time_before_search_sec < 0 ) {
160 // marker beacon blinking
161 bool light_on = ( outer_blink || middle_blink || inner_blink );
165 if ( light_on && (current - blink > 400000) ) {
168 } else if ( !light_on && (current - blink > 100000) ) {
173 if ( outer_marker ) {
174 outer_blink = light_on;
179 if ( middle_marker ) {
180 middle_blink = light_on;
182 middle_blink = false;
185 if ( inner_marker ) {
186 inner_blink = light_on;
191 // cout << outer_blink << " " << middle_blink << " "
192 // << inner_blink << endl;
194 inner_blink = middle_blink = outer_blink = false;
199 static bool check_beacon_range( double lon_rad, double lat_rad, double elev_m,
202 Point3D aircraft = sgGeodToCart( Point3D(lon_rad, lat_rad, elev_m) );
203 Point3D station = Point3D( b->get_x(), b->get_y(), b->get_z() );
204 // cout << " aircraft = " << aircraft << " station = " << station
207 double d = aircraft.distance3Dsquared( station ); // meters^2
208 // cout << " distance = " << d << " ("
209 // << FG_ILS_DEFAULT_RANGE * SG_NM_TO_METER
210 // * FG_ILS_DEFAULT_RANGE * SG_NM_TO_METER
213 // cout << " range = " << sqrt(d) << endl;
215 // cout << "elev = " << elev * SG_METER_TO_FEET
216 // << " current->get_elev() = " << current->get_elev() << endl;
217 double elev_ft = elev_m * SG_METER_TO_FEET;
218 double delev = elev_ft - b->get_elev_ft();
220 // max range is the area under r = 2.4 * alt or r^2 = 4000^2 - alt^2
221 // whichever is smaller. The intersection point is 1538 ...
222 double maxrange2; // feet^2
223 if ( delev < 1538.0 ) {
224 maxrange2 = 2.4 * 2.4 * delev * delev;
225 } else if ( delev < 4000.0 ) {
226 maxrange2 = 4000 * 4000 - delev * delev;
230 maxrange2 *= SG_FEET_TO_METER * SG_FEET_TO_METER; // convert to meter^2
231 // cout << "delev = " << delev << " maxrange = " << maxrange << endl;
233 // match up to twice the published range so we can model
234 // reduced signal strength
235 if ( d < maxrange2 ) {
242 // Update current nav/adf radio stations based on current postition
243 void FGMarkerBeacon::search()
247 _time_before_search_sec = 1.0;
249 static fgMkrBeacType last_beacon = NOBEACON;
251 double lon_rad = lon_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
252 double lat_rad = lat_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
253 double elev_m = alt_node->getDoubleValue() * SG_FEET_TO_METER;
255 ////////////////////////////////////////////////////////////////////////
257 ////////////////////////////////////////////////////////////////////////
259 // get closest marker beacon
261 = globals->get_mkrlist()->findClosest( lon_rad, lat_rad, elev_m );
263 // cout << "marker beacon = " << b << " (" << b->get_type() << ")" << endl;
265 fgMkrBeacType beacon_type = NOBEACON;
266 bool inrange = false;
268 if ( b->get_type() == 7 ) {
270 } else if ( b->get_type() == 8 ) {
271 beacon_type = MIDDLE;
272 } else if ( b->get_type() == 9 ) {
275 inrange = check_beacon_range( lon_rad, lat_rad, elev_m, b );
276 // cout << " inrange = " << inrange << endl;
279 outer_marker = middle_marker = inner_marker = false;
281 if ( b == NULL || !inrange || !has_power() || !serviceable->getBoolValue() )
283 // cout << "no marker" << endl;
284 globals->get_soundmgr()->stop( "outer-marker" );
285 globals->get_soundmgr()->stop( "middle-marker" );
286 globals->get_soundmgr()->stop( "inner-marker" );
287 } else if ( beacon_type == OUTER ) {
289 // cout << "OUTER MARKER" << endl;
290 if ( last_beacon != OUTER ) {
291 if ( ! globals->get_soundmgr()->exists( "outer-marker" ) ) {
292 SGSoundSample *sound = beacon.get_outer();
293 sound->set_volume( 0.3 );
294 globals->get_soundmgr()->add( sound, "outer-marker" );
297 if ( audio_btn->getBoolValue() ) {
298 if ( !globals->get_soundmgr()->is_playing("outer-marker") ) {
299 globals->get_soundmgr()->play_looped( "outer-marker" );
302 globals->get_soundmgr()->stop( "outer-marker" );
304 } else if ( beacon_type == MIDDLE ) {
305 middle_marker = true;
306 // cout << "MIDDLE MARKER" << endl;
307 if ( last_beacon != MIDDLE ) {
308 if ( ! globals->get_soundmgr()->exists( "middle-marker" ) ) {
309 SGSoundSample *sound = beacon.get_middle();
310 sound->set_volume( 0.3 );
311 globals->get_soundmgr()->add( sound, "middle-marker" );
314 if ( audio_btn->getBoolValue() ) {
315 if ( !globals->get_soundmgr()->is_playing("middle-marker") ) {
316 globals->get_soundmgr()->play_looped( "middle-marker" );
319 globals->get_soundmgr()->stop( "middle-marker" );
321 } else if ( beacon_type == INNER ) {
323 // cout << "INNER MARKER" << endl;
324 if ( last_beacon != INNER ) {
325 if ( ! globals->get_soundmgr()->exists( "inner-marker" ) ) {
326 SGSoundSample *sound = beacon.get_inner();
327 sound->set_volume( 0.3 );
328 globals->get_soundmgr()->add( sound, "inner-marker" );
331 if ( audio_btn->getBoolValue() ) {
332 if ( !globals->get_soundmgr()->is_playing("inner-marker") ) {
333 globals->get_soundmgr()->play_looped( "inner-marker" );
336 globals->get_soundmgr()->stop( "inner-marker" );
341 last_beacon = beacon_type;
343 last_beacon = NOBEACON;