I also think there are issues with syncing window changes, in general. IIRC, Owen Taylor wrote about this on his blog and was saying that that was one of the reasons why you can't drag a window around without there being some lag. I have to admit I don't understand why this is the case b/c it seems like the lag problem would of one of syncing cursor/input and drawing to vblank (i.e. compositor related, though I'm not sure what handles the cursor (maybe X itself thus you'd need to have X comunicate the position at a monotonic that is different than what the compositor is using for the scene?)). The other issue, as you touched on I believe, is that there is a texture separation between window contents and border (you know that gap tha between contents and border you get when doing wobbly windows?).
Originally Posted by nerdopolis
Anyway, I really see this as a TK issue.