[geeks] X [was Re: nVidia 8800GT for Apple Mac Pro]

[Shannon Hendrix]

On May 22, 2008, at 23:49 , der Mouse wrote:

>> You are talking about redraws triggered by expose events.
>
> Yes.
>
>> He's talking about redraws triggered by map and unmap events.
>
> That wokuld be...bizarre.  That's what Expose events are for; drawing
> based on MapNotify is pointless.

No, you are just hung on the word "draw".  To me any time pixels are  
put on screen it is drawing, even if it is just a copy triggered by  
asking for a window to be mapped.

I'm not talking about X conventions, but just literally when pixels  
are plotted, blitted, whatever.

Yes, I realize that by X documentation/terminology that isn't drawing.

Also, most of the time you end up with quite a few expose events when  
the WM maps a bunch of previously closed or "off screen" windows, so  
it is really a combination.

Hopefully backing store and more recently OpenGL tricks prevent a lot  
of expose events, but some will inevitably happen.

>> What he's talking about is that some X pagers "move" to another
>> desktop by telling one set of apps to unmap their windows, and
>> another to map them.
>
> Actually, the window manager (or session manager) is what maps and
> unmaps them; this isn't something the WM has to ask the client to do.

I know that, just didn't state it that way.

Also, it's not entirely true any more either.

Modern X has better standards for communication between apps and  
managers, and apps do now have code that deals with being paged,  
closed, moved, etc.

Some apps might want to do certain things if they are unmapped, or  
even request to be managed in some way.

For years that was a horrible mess.

The Free Desktop project was supposed to start helping standardize all  
of that stuff, making ICCCM stronger, etc.

> (Well, not in X.  As mentioned before, in a hybrid system like OS X,
> non-X clients may of course operate with non-X semantics.)
>
> If they get mapped and unmapped at all, of course; as you mention,
> off-desktop windows are sometimes just moved off-screen instead of
> being unmapped.

OpenGL opens up new possibilities of course, like using 2D surfaces in  
3D space to manage desktops.

I'm not sure how truly useful that is, but the end candy factor has  
people talking.

-- 
Shannon Hendrix
shannon at widomaker.com