Sub get_distance_p_l(xx, yy, x1, y1, x2, y2, distance)
    dx = (x2 - x1): dy = (y2 - y1)
    a = dx ^ 2 + dy ^ 2: b = dx * (x1 - xx) + dy * (y1 - yy)
    t = -b / a
    If t < 0 Then t = 0
    If t > 1 Then t = 1
    tx = x1 + dx * t: ty = y1 + dy * t
    distance = Sqr((xx - tx) ^ 2 + (yy - ty) ^ 2)
End Sub