w = 1024 : h = 600
open window w, h
color 255,0,0

incr = 0 : twopi = 2 * pi

while true
    incr = mod(incr + 0.05, twopi)
    x1 = w / 2
    y1 = h / 2
    length = 5
    angle = incr

    clear window

    for i = 1 to 151
        x2 = x1 + cos(angle) * length
        y2 = y1 + sin(angle) * length
        line x1, y1, x2, y2
        x1 = x2 : y1 = y2
        length = length + 3
        angle = mod(angle + incr, twopi)
    next
    pause 1
end while