   # Allows other methods to change the tween duration or disable it altogether.
   _setTweening: (speed) ->
     # To loop through the shaders, derive the correct pair from the current anchor.
-    if @lastOp.anchor is 'left' or @lastOp.anchor is 'right'
-      shaderPair = ['left', 'right']
-    else
-      shaderPair = ['top', 'bottom']
+    shaderPair = if @lastOp.anchor in anchorListV then anchorListV else anchorListH
 
     # Loop through the panels in this anchor and set the transition duration to the new speed.
     for panel, i in @panels[@lastOp.anchor]

    {@shading, @shadingIntensity, @vPanels, @hPanels} = @settings

    # Set an array of anchor names.
    @_anchors = ['left', 'right', 'top', 'bottom']
    # oriDomi starts oriented with the left anchor.
    @lastOp = anchor: @_anchors[0]
    # Create object literals to store panels and stages.
    @panels = {}
    @stages = {}

    # Disable tweening to enable instant 1 to 1 movement.
    @_setTweening 0
    # Derive the axis to fold on.
    @_touchAxis = if @lastOp.anchor in anchorListV then 'x' else 'y'
    # Set a reference to the last folded angle to accurately derive deltas.
    @["_#{ @_touchAxis }Last"] = @lastOp.angle

