State of XDBE

Adam Jackson ajax at
Tue Dec 14 13:08:50 PST 2010

On Tue, 2010-12-14 at 08:08 +0100, Lars Segerlund wrote:
> Hi All,
>  I am trying to add support for xdbe in xcb,  which in itself looks
> simple, but someone said that xdbe is deprecated ?

The major toolkits don't bother to use it, so presumably they think
explicitly managing the backing pixmap is a better idea.

>  The Composite extension is not really an option on small framebuffer
> devices ....


If what you mean is "small memory devices", DBE's not really a clear-cut
win for you there either.  You'll use less memory in the steady state of
no named buffers in your client, but when you do have named DBE buffers
(or whenever the DBE window gets resized) you'll need twice as much
memory as Composite would, since DBE creates pixmaps for both the front
and back buffers where Composite merely holds one offscreen pixmap.

Don't let this dissuade you from completing the XCB support for it, but
I _would_ dissuade you from trying to actually use DBE.

- ajax
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