X-Git-Url: https://git.openstreetmap.org/rails.git/blobdiff_plain/07976676decf321bffb3e1f3cb6782a15dae5ade..399fe3c12a7612f1ad79d376f2859d9c6fd38839:/app/assets/javascripts/osm.js.erb

diff --git a/app/assets/javascripts/osm.js.erb b/app/assets/javascripts/osm.js.erb
index 922bd2639..033b2de81 100644
--- a/app/assets/javascripts/osm.js.erb
+++ b/app/assets/javascripts/osm.js.erb
@@ -153,7 +153,7 @@ OSM = {
     center = center.wrap();
     layers = layers.replace('M', '');
 
-    var precision = zoomPrecision(zoom),
+    var precision = OSM.zoomPrecision(zoom),
       hash = '#map=' + zoom +
         '/' + center.lat.toFixed(precision) +
         '/' + center.lng.toFixed(precision);
@@ -163,5 +163,16 @@ OSM = {
     }
 
     return hash;
+  },
+
+  zoomPrecision: function(zoom) {
+    return Math.max(0, Math.ceil(Math.log(zoom) / Math.LN2));
+  },
+
+  locationCookie: function(map) {
+    var center = map.getCenter().wrap(),
+      zoom = map.getZoom(),
+      precision = OSM.zoomPrecision(zoom);
+    return [center.lng.toFixed(precision), center.lat.toFixed(precision), zoom, map.getLayersCode()].join('|');
   }
 };