module Main where import Graphics.Blank main = blankCanvas 3000 $ \ context -> loop context (0 :: Float) loop context n = do send context $ do (width,height) <- size clearRect (0,0,width,height) beginPath() save() translate (width / 2,height / 2) rotate (pi * n) beginPath() moveTo(-100,-100) lineTo(-100,100) lineTo(100,100) lineTo(100,-100) closePath() lineWidth 10 strokeStyle "green" stroke() restore() loop context (n + 0.01)