X-Git-Url: https://git.openstreetmap.org/rails.git/blobdiff_plain/0de6885a91e1740e3e2740287cb2d576de827844..479b22ca772c4a128ab7d4ff33cf6a7aba320be2:/app/assets/javascripts/osm.js.erb

diff --git a/app/assets/javascripts/osm.js.erb b/app/assets/javascripts/osm.js.erb
index 103110f7e..719c6b832 100644
--- a/app/assets/javascripts/osm.js.erb
+++ b/app/assets/javascripts/osm.js.erb
@@ -170,5 +170,20 @@ OSM = {
       zoom = map.getZoom(),
       precision = OSM.zoomPrecision(zoom);
     return [center.lng.toFixed(precision), center.lat.toFixed(precision), zoom, map.getLayersCode()].join('|');
+  },
+
+  distance: function(latlng1, latlng2) {
+    var lat1 = latlng1.lat * Math.PI / 180,
+      lng1 = latlng1.lng * Math.PI / 180,
+      lat2 = latlng2.lat * Math.PI / 180,
+      lng2 = latlng2.lng * Math.PI / 180,
+      latdiff = lat2 - lat1,
+      lngdiff = lng2 - lng1;
+
+    return 6372795 * 2 * Math.asin(
+      Math.sqrt(
+        Math.pow(Math.sin(latdiff / 2), 2) + 
+        Math.cos(lat1) * Math.cos(lat2) * Math.pow(Math.sin(lngdiff / 2), 2)
+      ));
   }
 };