src/ATC/groundlist.cxx

   1 // groundlist.cxx -- ATC Ground data management class
   2 //
   3 // Written by David Luff, started November 2002.
   4 // Based on navlist.cxx by Curtis Olson, started April 2000.
   5 //
   6 // Copyright (C) 2000  Curtis L. Olson - curt@flightgear.org
   7 //
   8 // This program is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU General Public License as
  10 // published by the Free Software Foundation; either version 2 of the
  11 // License, or (at your option) any later version.
  12 //
  13 // This program is distributed in the hope that it will be useful, but
  14 // WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 // General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include <config.h>
  25 #endif
  26
  27 #include <simgear/debug/logstream.hxx>
  28 #include <simgear/misc/sgstream.hxx>
  29 #include <simgear/math/sg_geodesy.hxx>
  30 #include <simgear/math/sg_random.h>
  31
  32 #include "groundlist.hxx"
  33
  34 FGGroundList *current_groundlist;
  35
  36 // Constructor
  37 FGGroundList::FGGroundList( void ) {
  38 }
  39
  40
  41 // Destructor
  42 FGGroundList::~FGGroundList( void ) {
  43 }
  44
  45
  46 // load the navaids and build the map
  47 bool FGGroundList::init( SGPath path ) {
  48
  49         groundlist.erase( groundlist.begin(), groundlist.end() );
  50
  51         sg_gzifstream in( path.str() );
  52         if ( !in.is_open() ) {
  53                 SG_LOG( SG_GENERAL, SG_ALERT, "Cannot open file: " << path.str() );
  54                 exit(-1);
  55         }
  56
  57         // read in each line of the file
  58
  59         in >> skipcomment;
  60
  61         #ifdef __MWERKS__
  62         char c = 0;
  63         while ( in.get(c) && c != '\0' ) {
  64                 in.putback(c);
  65                 #else
  66                 while ( !in.eof() ) {
  67                         #endif
  68
  69                         FGGround g;
  70                         in >> g;
  71                         if ( g.get_type() == '[' ) {
  72                                 break;
  73                         }
  74
  75                         //cout << "id = " << t.GetIdent() << endl;
  76                         //cout << " type = " << t.get_type() << endl;
  77                         //cout << " lon = " << t.get_lon() << endl;
  78                         //cout << " lat = " << t.get_lat() << endl;
  79                         //cout << " elev = " << t.get_elev() << endl;
  80                         //cout << " freq = " << t.get_freq() << endl;
  81                         //cout << " range = " << t.get_range() << endl;
  82
  83                         groundlist[g.get_freq()].push_back(g);
  84                         in >> skipcomment;
  85                 }
  86
  87                 return true;
  88         }
  89
  90
  91         // query the database for the specified frequency, lon and lat are in
  92         // degrees, elev is in meters
  93         bool FGGroundList::query( double lon, double lat, double elev, double freq,
  94         FGGround *g )
  95         {
  96                 lon *= SGD_DEGREES_TO_RADIANS;
  97                 lat *= SGD_DEGREES_TO_RADIANS;
  98                 //cout << "lon = " << lon << '\n';
  99                 //cout << "lat = " << lat << '\n';
 100                 //cout << "elev = " << elev << '\n';
 101                 //cout << "freq = " << freq << '\n';
 102
 103                 ground_list_type stations = groundlist[(int)(freq*100.0 + 0.5)];
 104
 105                 ground_list_iterator current = stations.begin();
 106                 ground_list_iterator last = stations.end();
 107
 108                 // double az1, az2, s;
 109                 Point3D aircraft = sgGeodToCart( Point3D(lon, lat, elev) );
 110                 Point3D station;
 111                 double d;
 112                 for ( ; current != last ; ++current ) {
 113                         //cout << "testing " << current->GetIdent() << endl;
 114                         station = Point3D(current->get_x(), current->get_y(), current->get_z());
 115                         //cout << "aircraft = " << aircraft << endl;
 116                         //cout << "station = " << station << endl;
 117
 118                         d = aircraft.distance3Dsquared( station );
 119
 120                         //cout << "  dist = " << sqrt(d)
 121                         //     << "  range = " << current->get_range() * SG_NM_TO_METER << endl;
 122
 123                         // match up to twice the published range so we can model
 124                         // reduced signal strength
 125                         if ( d < (2 * current->get_range() * SG_NM_TO_METER
 126                                 * 2 * current->get_range() * SG_NM_TO_METER ) ) {
 127                                         //cout << "matched = " << current->GetIdent() << endl;
 128                                         *g = *current;
 129                                         return true;
 130                                 }
 131                 }
 132
 133                 return false;
 134         }