handle closing windows

src/Events.hs

@@ -4,15 +4,24 @@ import qualified SDL
 
 import Linear
 
+import Control.Concurrent.MVar
+
 -- internal impomrts
 
 import Util
 
-eventHandler :: SDL.Event -> IO ()
-eventHandler (SDL.Event _ payload) =
-  handlePayload payload
+eventHandler :: MVar Bool -> SDL.Event -> IO ()
+eventHandler run (SDL.Event _ payload) =
+  handlePayload run payload
 
-handlePayload :: SDL.EventPayload -> IO ()
-handlePayload (SDL.WindowResizedEvent (SDL.WindowResizedEventData _ dim)) =
+handlePayload :: MVar Bool -> SDL.EventPayload -> IO ()
+
+handlePayload _ (SDL.WindowResizedEvent (SDL.WindowResizedEventData _ dim)) =
   fitViewport (800 / 600) dim
-handlePayload _ = return ()
+
+handlePayload run (SDL.WindowClosedEvent _) = do
+  _ <- swapMVar run False
+  return ()
+
+-- catch all other events
+handlePayload _ _ = return ()

src/Main.hs

@@ -101,7 +101,7 @@ main = do
     mapM_ (\(ident, context) -> do
       let win = fromJust (lookup ident wins)
       SDL.glMakeCurrent win context
-      mapM_ eventHandler =<< SDL.pollEvents
+      mapM_ (eventHandler run) =<< SDL.pollEvents
       GL.clear [GL.ColorBuffer, GL.DepthBuffer, GL.StencilBuffer]
       GL.flush
       SDL.glSwapWindow win