fill-x()
  l 0
  r 0

fill-y()
  t 0
  b 0      

fill(dir = a, fix = false)
  if fix
    pos abso
  else
    pos fixed

  if dir is x
    fill-x()
  else if dir is y
    fill-y()
  else if dir is t
    t 0
    fill-x()
  else if dir is b
    b 0
    fill-x()
  else if dir is l
    l 0
    fill-y()
  else if dir is r
    r 0
    fill-y()
  else if dir is tl
    t 0
    l 0
  else if dir is tr
    t 0
    r 0
  else if dir is bl
    b 0
    l 0
  else if dir is br
    b 0
    r 0
  else
    fill-x()
    fill-y()