fixed problem in google maps with wrapped maps

lib/torque/gmaps/CanvasLayer.js

@@ -443,6 +443,14 @@ CanvasLayer.prototype.repositionCanvas_ = function() {
   // overlayView's projection, not the map's
   var projection = this.getProjection();
   var divTopLeft = projection.fromLatLngToDivPixel(this.topLeft_);
+
+  console.log(this.topLeft_.lng(), divTopLeft.x);
+  // when the zoom level is low, more than one map can be shown in the screen
+  // so the canvas should be attach to the map with more are in the screen
+  var mapSize = (1 << this.getMap().getZoom())*256;
+  if (Math.abs(divTopLeft.x) > mapSize) {
+    divTopLeft.x -= mapSize;
+  }
   this.canvas.style[CanvasLayer.CSS_TRANSFORM_] = 'translate(' +
       Math.round(divTopLeft.x) + 'px,' + Math.round(divTopLeft.y) + 'px)';
 

lib/torque/gmaps/gmaps_tileloader_mixin.js

@@ -105,6 +105,13 @@ GMapsTileLoader.prototype = {
   },
 
   getTilePos: function (tilePoint) {
+    var limit = (1 << this._map.getZoom());
+    // wrap tile
+    tilePoint = {
+      x: ((tilePoint.x % limit) + limit) % limit,
+      y: tilePoint.y
+    };
+
     tilePoint = new google.maps.Point(
       tilePoint.x * this.tileSize, 
       tilePoint.y * this.tileSize