size 200 200 paper 100 fast command rects x y w h r g b { pen r g b repeat w1 10 h { pen r g b line (x+(w1/2)) (y-h/2) (x+(w1/2)) (y-h/2) line (x-(w1/2)) (y-h/2) (x+(w1/2)) (y+h/2) line (x+(w1/2)) (y+h/2) (x+(w1/2)) (y+h/2) line (x+(w1/2)) (y-h/2) (x-(w1/2)) (y+h/2) } } forever { rects 10 14