Added a function to return the closest ATC station of a given type

diff --git a/src/ATC/commlist.cxx b/src/ATC/commlist.cxx
index 8f282ea3bac8fd8cfd2f2cab40be5b2540c35fc4..36c5f88b53130ffecdaffe0da7cf4536bdc2903c 100644 (file)
--- a/src/ATC/commlist.cxx
+++ b/src/ATC/commlist.cxx
@@ -209,6 +209,52 @@ int FGCommList::FindByPos(double lon, double lat, double elev, double range, com
 }
 
 
+// Returns the distance in meters to the closest station of a given type,
+// with the details written into ATCData& ad.  If no type is specifed simply
+// returns the distance to the closest station of any type.
+// Returns -9999 if no stations found within max_range in nautical miles (default 100 miles).
+// Note that the search algorithm starts at 10 miles and multiplies by 10 thereafter, so if
+// say 300 miles is specifed 10, then 100, then 1000 will be searched, breaking at first result 
+// and giving up after 1000.
+double FGCommList::FindClosest( double lon, double lat, double elev, ATCData& ad, atc_type tp, double max_range) {
+       int num_stations = 0;
+       int range = 10;
+       comm_list_type stations;
+       comm_list_iterator itr;
+       double distance = -9999.0;
+       
+       while(num_stations == 0) {
+               num_stations = FindByPos(lon, lat, elev, range, &stations, tp);
+               if(num_stations) {
+                       double closest = max_range * SG_NM_TO_METER;
+                       double tmp;
+                       for(itr = stations.begin(); itr != stations.end(); ++itr) {     
+                               ATCData ad2 = *itr;
+                               //Point3D p1(*itr.lon, *itr.lat, *itr.elev);
+                               Point3D p1(ad2.lon, ad2.lat, ad2.elev);
+                               FGAirport a;
+                               if(dclFindAirportID(ad2.ident, &a)) {
+                                       Point3D p2(lon, lat, elev);
+                                       tmp = dclGetHorizontalSeparation(p1, p2);
+                                       if(tmp <= closest) {
+                                               closest = tmp;
+                                               distance = tmp;
+                                               ad = *itr;
+                                       }
+                               }
+                       }
+                       //cout << "Closest station is " << ad.ident << " at a range of " << distance << " meters\n";
+                       return(distance);
+               }
+               if(range > max_range) {
+                       break;
+               }
+               range *= 10;
+       }
+       return(-9999.0);
+}
+
+
 // Find by Airport code.
 // This is basically a wrapper for a call to the airport database to get the airport
 // position followed by a call to FindByPos(...)

diff --git a/src/ATC/commlist.hxx b/src/ATC/commlist.hxx
index 873d870be6d0b45dc329791f95a6e2196e14cc38..74ee43a4350c2cbc783bd432d92036b1f429548d 100644 (file)
--- a/src/ATC/commlist.hxx
+++ b/src/ATC/commlist.hxx
@@ -84,6 +84,17 @@ public:
        // ** stations is erased before use **
     int FindByPos( double lon, double lat, double elev, double range, comm_list_type* stations, atc_type tp = INVALID );
        
+       // Returns the distance in meters to the closest station of a given type,
+       // with the details written into ATCData& ad.  If no type is specifed simply
+       // returns the distance to the closest station of any type.
+       // Returns -9999 if no stations found within max_range in nautical miles (default 100 miles).
+       // Note that the search algorithm starts at 10 miles and multiplies by 10 thereafter, so if
+       // say 300 miles is specifed 10, then 100, then 1000 will be searched, breaking at first result 
+       // and giving up after 1000.
+       // !!!Be warned that searching anything over 100 miles will pause the sim unacceptably!!!
+       //      (The ability to search longer ranges should be used during init only).
+       double FindClosest( double lon, double lat, double elev, ATCData& ad, atc_type tp = INVALID, double max_range = 100.0 );
+       
        // Find by Airport code.
        bool FindByCode( string ICAO, ATCData& ad, atc_type tp = INVALID );