Trick around graphics limitations  

$$B Trick around graphics limitations
$$ +--------------------
$$ | + + + + + + + + + +
$$ | + . X . . X . X . .
$$ | + X X . . X X X . .
$$ | + . . . . . . . . .
$$ {LN 1:1 1:3}
$$ {LN 1:3 3:3}
$$ {LN 3:3 3:1}
$$ {LN 3:1 1:1}
$$ {LN 6:1 6:3}
$$ {LN 6:3 8:3}
$$ {LN 8:3 8:1}
$$ {LN 8:1 6:1}