rotating-pentagon.elm

import Window

tick : Signal Float
tick = (((+) 100) . toFloat . ((flip mod) 100)) <~ count (fps 25)

shape : Float -> Form
shape i = ngon 5 20
           |> filled (hsva (i / 16) 0.5 1.0 1.0)
           |> rotate (64 / i)
           |> scale (i / 10)

scene : Float -> [Form]
scene i = if i < 4 then []
                   else [shape i] ++ scene (i / 2)

main : Signal Element
main = let dims = Window.dimensions
       in collage <~ (fst <~ dims) ~ (snd <~ dims) ~ (scene <~ tick)