local fn DoIt
  NSInteger  i, t
  double     length, incr, x1, y1, x2, y2, twopi, angle, w, h

  pen 2.0, fn ColorRed, NSLineCapStyleButt, NULL, 0

  incr = 0 : twopi = 2 * pi
  w = 600  : h = 600

  t = 150
  while ( t > 0 )
    incr = ( incr + 0.05 mod twopi )
    x1 = w / 2
    y1 = h / 2
    length = 1.0
    angle = incr
    line to x1, y1
    cls
    for i = 1 to 300
      x2 = x1 + cos( angle ) * length
      y2 = y1 + sin( angle ) * length
      line to x1, y1 to x2, y2
      x1 = x2 : y1 = y2
      length = length + 1.0
      angle = ( angle + incr mod twopi )
    next
    t--
  wend
end fn

window 1, @"Rosetta Code Polyspiral", fn CGRectMake( 0, 0, 600, 600 )
WindowSetBackgroundColor( 1, fn ColorBlack )

fn DoIt

HandleEvents