renderRW :: Canvas -> Seed -> Int -> IO ()
renderRW canv seed n = let
    r = fromIntegral (size `div` 2)
    walk = map (\(x,y) -> (x*2,y*2)) $ randWalkN (-1,1) seed n
    in do
        render canv . translate (r,r) . color backColor .  stroke . path $ walk
        renderOnTop canv . translate (r,r) .
             color mainColor .  stroke . path $ eraseWhole walk
renderRW :: Canvas -> Seed -> Int -> IO ()
renderRW canv seed n = let
    r = fromIntegral (size `div` 2)
    walk = map (\(x,y) -> (x*2,y*2)) $ randWalkN (-1,1) seed n
    in do
        render canv . translate (r,r) . color backColor .  stroke . path $ walk
        renderOnTop canv . translate (r,r) .
             color mainColor .  stroke . path $ eraseWhole walk
renderRW canv seed n = let
    r = fromIntegral (size `div` 2)
    walk = map (\(x,y) -> (x*2,y*2)) $ randWalkN (-1,1) seed n
    in do
        render canv . translate (r,r) . color backColor .  stroke . path $ walk
        renderOnTop canv . translate (r,r) .
             color mainColor .  stroke . path $ eraseWhole walk