showWorld :: IORef World -> IO ()
showWorld worldRef = do
    clear [ColorBuffer]
    world <- readIORef worldRef
    drawSquares world
    swapBuffers
showWorld :: IORef World -> IO ()
showWorld worldRef = do
    clear [ColorBuffer]
    world <- readIORef worldRef
    drawSquares world
    swapBuffers
showWorld worldRef = do
    clear [ColorBuffer]
    world <- readIORef worldRef
    drawSquares world
    swapBuffers