     @el.innerHTML = ''
     @el.appendChild @cleanEl
     @el.appendChild @stageEl
+
+    # These properties record starting angles for touch/drag events.
+    # Initialize both to zero.
+    [@_xLast, @_yLast] = [0, 0]
 
     # Cache a jQuery object of the element if applicable.
     @$el = $ @el if $

      @reset =>
        # Show the stage element of the originally requested anchor.
        @_showStage anchor

        # Defer this operation until the next event loop to prevent a sudden jump.
        setTimeout =>
          # `foldUp` is a special method that doesn't accept an angle argument.

      callback?()


  # Enables touch events and sets cursor.
  enableTouch: ->
    @_touchEnabled = true
    @_setCursor()


  # Disables touch events.
  disableTouch: ->
    @_touchEnabled = false
    @_setCursor()


  # Convenient way to retrieve an oriDomi instance from jQuery object.
  # For example, `$oriDiv.oriDomi('getInstance')` will return the oriDomi instance
  # instead of the jQuery selection.
