Fix resize hang.

2 files changed, 1 insertions, 2 deletions

diff --git a/Demos/Pong/Main.hs b/Demos/Pong/Main.hs
index 0237a26..26ceefa 100644
--- a/Demos/Pong/Main.hs
+++ b/Demos/Pong/Main.hs
@@ -98,7 +98,6 @@ renderGO go = do
       ,vec2 xmax ymax
       ,vec2 xmin ymax)]
 
--- TODO: Fix the resize hang.
 resize :: WindowEvent -> Game GameState ()
 resize (ResizeEvent w h) =
   let r = fromIntegral w / fromIntegral h
diff --git a/Spear/Window.hs b/Spear/Window.hs
index 3cdc5f5..aafcb59 100644
--- a/Spear/Window.hs
+++ b/Spear/Window.hs
@@ -178,7 +178,7 @@ onWindowClose closeRequest window = putMVar closeRequest True
 -- the last in a poll can be ignored, we just replace the contents of the mvar
 -- here instead of adding the event to the list.
 onResize :: MVar [WindowEvent] -> GLFW.WindowSizeCallback
-onResize windowEvents window w h = putMVar windowEvents [ResizeEvent w h]
+onResize windowEvents window w h = modifyMVar_ windowEvents (return <$> const [ResizeEvent w h])
 
 onKey :: MVar [InputEvent] -> GLFW.KeyCallback
 onKey events window key _ GLFW.KeyState'Pressed   _ = addEvent events $ KeyDown (fromGLFWkey key)