XRender/Xcomposite semantics (issues?)

[Keith Packard]

On Thu, 2006-03-09 at 11:17 +0900, Carsten Haitzler wrote:

> now this brings up a big fat ugly problem... what IF the wm wants to
> have an argb FRAME (a window border design with alpha) but a CLIENT is
> old-school and non ARGB. all "child" windows of an ARGB window have
> their alpha channel basically not filled in solid automatically - this
> leads to some problems if a wm ever wants to do this. it REQUIRES the
> client to realise its frame is ARGB before mapping - in fact creating
> its window, so it can also be ARGB and fill dst alpha right.

The client is free to create an RGB window. When that is placed within
an ARGB window, the server will automatically redirect it to a pixmap
separate from the frame and paint frame contents with the client window
as it changes. This 'should' work, although you can see that it won't be
stunningly efficient.

The best approach we've found so far is for the wm to be the same as the
cm (composite manager), and to paint the frame right onto the desktop
without reparenting the client windows at all. That way it gets whatever
semantics it wants for the frame contents, and gets to do whatever it
wants with window contents as well.

-- 
keith.packard at intel.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL: <http://lists.x.org/archives/xorg/attachments/20060308/2b5b14f9/attachment.pgp>