Re: [AD] al_set_mouse_xy asynchronous on X

[Peter Wang <novalazy@xxxxxxxxxx>]

On Sat, 23 Feb 2013 22:46:05 -0700, Trent Gamblin <nooskewl@xxxxxxxxxx> wrote:
> This poses a problem. In my game I have (simplified):
> 
> al_set_mouse_xy(...);
> // bunch of code later
> al_get_mouse_state();
> // state.x/y are still not the same as I set them
> 
> So my submarine crashes.
> 
> The fix that I think should be applied (but I want to check with the X/Linux "guys") is an XFlush in the X set_mouse_xy implementation. Works like a charm.
> 

That wouldn't really do it.  The XFlush forces the message out of the
library's buffer to the X server, but there's no guarantee that the X
server sends back the pointer moved event, and that it is processed by
the time you call al_get_mouse_state().

Also, wouldn't your code still be susceptible to the X event thread
changing the mouse state after the [synchronous] al_set_mouse_xy call
and al_get_mouse_state?

Peter