Re: X cursor

On Fri, 2003-11-14 at 05:22, Keith Packard wrote:
> Around 21 o'clock on Nov 13, David Morse wrote:
> 
> > I've always wondered, what *is* the mouse cursor?  Do video cards have a 
> > 2 bit overlay plane just for the mouse cursor, or are they doing 
> > save-unders, or what?
> 
> Most have a 2-bit overlay, newer ones have a 32-bit ARGB overlay.  Using
> the overlay is really nice as it allows you to update the mouse position
> from the mouse input processing handler directly (a SIGIO handler in most
> Linux X servers).

That may actually be undesirable though under some circumstances, e.g.
when you move a window and it lags behind the cursor slightly. Might be
better to decouple keeping track of the cursor position (possibly still
via SIGIO) and rendering it (preferably composing it along with
everything else).


-- 
Earthling Michel Dänzer      |     Debian (powerpc), X and DRI developer
Software libre enthusiast    |   http://svcs.affero.net/rm.php?r=daenzer