Return the closest match instead of the first in-range match when searching by frequency

diff --git a/src/ATC/commlist.cxx b/src/ATC/commlist.cxx
index dabb44b36bfc886ed086d4dd598c9d963f2aaa53..8d13b31339f5cd097118c3077e8eed2e978f5378 100644 (file)
--- a/src/ATC/commlist.cxx
+++ b/src/ATC/commlist.cxx
@@ -138,6 +138,8 @@ bool FGCommList::FindByFreq( double lon, double lat, double elev, double freq,
        // double az1, az2, s;
        Point3D aircraft = sgGeodToCart( Point3D(lon, lat, elev) );
        Point3D station;
+       const double orig_max_d = 1e100; 
+       double max_d = orig_max_d;
        double d;
        // TODO - at the moment this loop returns the first match found in range
        // We want to return the closest match in the event of a frequency conflict
@@ -150,21 +152,28 @@ bool FGCommList::FindByFreq( double lon, double lat, double elev, double freq,
                d = aircraft.distance3Dsquared( station );
                
                //cout << "  dist = " << sqrt(d)
-               //     << "  range = " << current->get_range() * SG_NM_TO_METER << endl;
+               //     << "  range = " << current->range * SG_NM_TO_METER << endl;
                
-               // match up to twice the published range so we can model
+               // TODO - match up to twice the published range so we can model
                // reduced signal strength
-               if ( d < (2 * current->range * SG_NM_TO_METER 
-               * 2 * current->range * SG_NM_TO_METER ) ) {
-                       //cout << "matched = " << current->get_ident() << endl;
+               // NOTE The below is squared since we match to distance3Dsquared (above) to avoid a sqrt.
+               if ( d < (current->range * SG_NM_TO_METER 
+                    * current->range * SG_NM_TO_METER ) ) {
+                       //cout << "matched = " << current->ident << endl;
                        if((tp == INVALID) || (tp == (*current).type)) {
-                               *ad = *current;
-                               return true;
+                               if(d < max_d) {
+                                       max_d = d;
+                                       *ad = *current;
+                               }
                        }
                }
        }
        
-       return false;
+       if(max_d < orig_max_d) {
+               return true;
+       } else {
+               return false;
+       }
 }
 
 int FGCommList::FindByPos(double lon, double lat, double elev, double range, comm_list_type* stations, atc_type tp)
@@ -200,8 +209,9 @@ int FGCommList::FindByPos(double lon, double lat, double elev, double range, com
                                if((current->type == tp) || (tp == INVALID)) {
                                        station = Point3D(current->x, current->y, current->z);
                                        d = aircraft.distance3Dsquared( station );
-                                       if ( d < (current->range * SG_NM_TO_METER 
-                                       * current->range * SG_NM_TO_METER ) ) {
+                                       // NOTE The below is squared since we match to distance3Dsquared (above) to avoid a sqrt.
+                                       if ( d < (current->range * SG_NM_TO_METER
+                                            * current->range * SG_NM_TO_METER ) ) {
                                                stations->push_back(*current);
                                                ++found;
                                        }