altos-mapd: Check nearest portion of tile to launch site

[fw/altos] / map-server / altos-mapd / AltosMapd.java

diff --git a/map-server/altos-mapd/AltosMapd.java b/map-server/altos-mapd/AltosMapd.java
index b4105861049c3e648639e75d86a6e09e236d0c7a..1be1655d5eddfd88c0c98cfb76907d4b0cb31989 100644 (file)
--- a/map-server/altos-mapd/AltosMapd.java
+++ b/map-server/altos-mapd/AltosMapd.java
@@ -57,7 +57,23 @@ public class AltosMapd implements AltosLaunchSiteListener {
                }
        }
 
-       public static boolean check_lat_lon(double lat, double lon) {
+       private static boolean west_of(double a, double b) {
+               double  diff = b - a;
+
+               while (diff >= 360.0)
+                       diff -= 360.0;
+               while (diff <= -360.0)
+                       diff += 360.0;
+
+               return diff >= 0;
+       }
+
+       public static boolean check_lat_lon(double lat, double lon, int zoom) {
+               AltosMapTransform       transform = new AltosMapTransform(px_size, px_size, zoom, new AltosLatLon(lat, lon));
+
+               AltosLatLon             upper_left = transform.screen_lat_lon(new AltosPointInt(0, 0));
+               AltosLatLon             lower_right = transform.screen_lat_lon(new AltosPointInt(px_size, px_size));
+
                synchronized (launch_sites_ready) {
                        if (launch_sites == null) {
                                try {
@@ -73,8 +89,34 @@ public class AltosMapd implements AltosLaunchSiteListener {
                }
 
                for (AltosLaunchSite site : launch_sites) {
+
+                       /* Figure out which point in the tile to
+                        * measure to the site That's one of the edges
+                        * or the site location depend on where the
+                        * site is in relation to the tile
+                        */
+
+                       double          check_lon;
+
+                       if (west_of(site.longitude, upper_left.lon))
+                               check_lon = upper_left.lon;
+                       else if (west_of(lower_right.lon, site.longitude))
+                               check_lon = lower_right.lon;
+                       else
+                               check_lon = site.longitude;
+
+                       double          check_lat;
+
+                       if (site.latitude < lower_right.lat)
+                               check_lat = lower_right.lat;
+                       else if (upper_left.lat < site.latitude)
+                               check_lat = upper_left.lat;
+                       else
+                               check_lat = site.latitude;
+
                        AltosGreatCircle gc = new AltosGreatCircle(site.latitude, site.longitude,
-                                                                  lat, lon);
+                                                                  check_lat, check_lon);
+
                        if (gc.distance <= valid_radius)
                                return true;
                }