don't waste coordinate space by using a smaller renderer extent and updating it on moveend. r=bartvde (closes #3359)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@12163 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Renderer/NG.js

@@ -38,10 +38,14 @@ OpenLayers.Renderer.NG = OpenLayers.Class(OpenLayers.Renderer.Elements, {
      * To be extended by subclasses - here we set positioning related styles
      * on HTML elements, subclasses have to do the same for renderer specific
      * elements (e.g. viewBox, width and height of the rendererRoot)
+     *
+     * Parameters:
+     * zoomChanged - {Boolean} Has the zoom changed? If so, subclasses may have
+     *     to update feature styles/dimensions.
      */
-    updateDimensions: function() {
+    updateDimensions: function(zoomChanged) {
         var mapExtent = this.map.getExtent();
-        var renderExtent = this.map.getMaxExtent();
+        var renderExtent = mapExtent.scale(3);
         this.setExtent(renderExtent, true);
         var res = this.getResolution();
         var div = this.rendererRoot.parentNode;