void local fn BarnsleyFern( height as long )
  double x = 0, y = 0, xn, yn, f = height / 10.6
  long n, r, offsetX = height / 4 - height / 40

  for n = 1 to height * 50
    r = rnd(100) - 1
    select
      case r >= 0 && r <= 84
        xn = 0.85 * x + 0.04 * y
        yn = -0.04 * x + 0.85 * y + 1.6
      case r >= 85 && r <= 91
        xn = 0.2 * x - 0.26 * y
        yn = 0.23 * x + 0.22 * y + 1.6
      case r >= 92 && r <= 98
        xn = -0.15 * x + 0.28 * y
        yn = 0.26 * x + 0.24 * y + 0.44
      case else
        xn = 0
        yn = 0.16 * y
    end select

    x = xn : y = yn
    pen -1
    oval fill (offsetX + x * f, height - y * f, 1.5, 1.5), _zGreen
  next

end fn

window 1, @"Barnsley fern", (0,0,300,600)
WindowSetBackgroundColor( 1, fn ColorBlack )

fn BarnsleyFern( 600 )

HandleEvents