ender ()
renderSlide s p w h = do
  renderSlideFilter w h (s !! p)
  renderTurtle $ toDouble p / toDouble (length s - 1)

renderSlide :: [[Double -> C.Render Double]] -> Int -> Int -> Int -> C.Render ()
renderSlide s p w h = do
  renderSlideFilter w h (s !! p)
  renderTurtle $ toDouble p / toDouble (length s - 1)
renderSlide s p w h = do
  renderSlideFilter w h (s !! p)
  renderTurtle $ toDouble p / toDouble (length s - 1)