oops, didn't intend to commit this :-)

src/maps.js

@@ -91,6 +91,7 @@ WorldMap.prototype.refresh = function () {
 };
 
 WorldMap.prototype.wrapTile = function (n) {
+    // currently unused
     var max = Math.pow(2, this.zoom);
     return n < 0 ? max - n : n % max;
 };
@@ -179,7 +180,7 @@ WorldMap.prototype.render = function () {
     ctx = this.canvas.getContext('2d');
     for (x = 0; x < tileGrid.x; x += 1) {
         for (y = 0; y < tileGrid.y; y += 1) {
-            tileX = this.wrapTile(originTile.x + x);
+            tileX = originTile.x + x;
             tileY = originTile.y + y;
             if ((tileX >= 0 && tileX < max) && (tileY >= 0 && tileY < max)) {
                 img = new Image();