     half = scale / 2
     "m#{-half},#{-half}  h#{scale} v#{scale} h-#{scale } v#{-scale}"
   signals: {
-    left:  {name: "L", do: "turn", dir: 1}
-    right: {name: "R", do: "turn", dir: -1}
+    left:  {name: "LL", do: "turn", dir: 1}
+    right: {name: "RR", do: "turn", dir: -1}
     front: {name: "GO", do: "go", dir: 1}
     back: {name: "REV", do: "go", dir: -1}
     step: {name: "1>", do: "step", n: 1}

    col: 0
    i: (world, args) -> offset(world, 'col')
    j: (world, args) -> offset(world, 'row')
    click: (world, args) ->
      action = world.get('action')
      current = world.get('current')
      #console.log "click #{world} -> #{current} do #{action}"
      current.call(action['do'], action)
  }
  _CHILDREN: [

        current = world.get('current')
        "#{current} #{current.get('i')}x#{current.get('j')} -> #{current.get('v_i')}x#{current.get('v_j')}"
    }
    {_LABEL: "left", row: 1, col: 0}
    {_LABEL: "front", row: 1, col: 1}
    {_LABEL: "right", row: 1, col: 2}
    {
      row: 2, col: 0
      name: "Step"
