Re: X cursor

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).

So, the server ends up supporting software cursor for cards that don't 
have ARGB overlays (as modern cursors are all multi color), and also for 
cursors which don't fit in the overlay.

I guess we need to figure out precisely how the various systems glue would 
glue together with a GL accelerated X server so that we can add hooks in 
the right places to get from the mouse to the cursor.

-keith