+ function getTileURL( bounds ) {
+ var res = this.map.getResolution();
+ var x = Math.round ((bounds.left - this.maxExtent.left) / (res * this.tileSize.w));
+ var y = Math.round ((this.maxExtent.top - bounds.top) / (res * this.tileSize.h));
+ var z = this.map.getZoom();
+ return this.url + z + "/" + x + "/" + y + "." + this.type;
+ }
+