# Scrolling map
      vx = 0
      vy = 0
      Crafty.addEvent document, Crafty.stage.elem, 'mousedown', (e) ->
      return if e.button > 1
      base = { x: e.clientX, y: e.clientY }
      scroll = (e) ->
        dx = base.x - e.clientX
        dy = base.y - e.clientY
        base = { x: e.clientX, y: e.clientY }
        Crafty.viewport.x = (vx -= dx)
        Crafty.viewport.y = (vy -= dy)

      Crafty.addEvent document, Crafty.stage.elem, 'mousemove', scroll
      Crafty.addEvent document, Crafty.stage.elem, 'mouseup', ->
        Crafty.removeEvent document, Crafty.stage.elem, 'mousemove', scroll