Optimize arc filter to stop computing distances once a point is close enough

diff --git a/gpsbabel/arcdist.c b/gpsbabel/arcdist.c
index 27499bf1e272908ca0d5b4127b4f222acaaa2198..be5d1576b301bc455733a8dedf59b5d038b5c15e 100644 (file)
--- a/gpsbabel/arcdist.c
+++ b/gpsbabel/arcdist.c
@@ -90,20 +90,6 @@ arcdist_process(void)
              QUEUE_FOR_EACH(&waypt_head, elem, tmp) {
 
                waypointp = (waypoint *)elem;
-               if ( ptsopt ) {
-                  dist = gcdist( lat2*M_PI/180.0, lon2*M_PI/180.0, 
-                                  waypointp->latitude*M_PI/180.0, 
-                                  waypointp->longitude*M_PI/180.0 );
-               }
-               else {
-                  dist = linedist(lat1, lon1, lat2, lon2, 
-                               waypointp->latitude,
-                               waypointp->longitude );
-               }
-
-               /* convert radians to float point statute miles */
-               dist = tomiles(dist);
-
                if ( waypointp->extra_data ) {
                        ed = (extra_data *) waypointp->extra_data;
                }
@@ -111,10 +97,26 @@ arcdist_process(void)
                        ed = (extra_data *) xcalloc(1, sizeof(*ed));
                        ed->distance = BADVAL;
                }
-               if ( ed->distance > dist ) {
+               if ( ed->distance == BADVAL || ed->distance >= pos_dist ) {
+                  if ( ptsopt ) {
+                     dist = gcdist( lat2*M_PI/180.0, lon2*M_PI/180.0, 
+                                  waypointp->latitude*M_PI/180.0, 
+                                  waypointp->longitude*M_PI/180.0 );
+                  }
+                  else {
+                     dist = linedist(lat1, lon1, lat2, lon2, 
+                               waypointp->latitude,
+                               waypointp->longitude );
+                  }
+
+                  /* convert radians to float point statute miles */
+                  dist = tomiles(dist);
+
+                  if ( ed->distance > dist ) {
                        ed->distance = dist;
+                  }
+                  waypointp->extra_data = ed;
                }
-               waypointp->extra_data = ed;
              }
            }
            lat1 = lat2;