Window scaling (aka owner sizes)

Giuseppe Bilotta giuseppe.bilotta at
Mon Aug 27 09:00:47 UTC 2018

Hello Keith,

On Mon, Aug 27, 2018 at 8:25 AM Keith Packard <keithp at> wrote:
> I'm doing a bit of work to help support applications that want to run at
> a small fixed size.

Wonderful endeavor.

> The basic plan is to make the size-as-seen-by-the-owner different from
> the size seen by the rest of the system, and then to either have the
> server scale the output or get the compositing manager to do it.

I guess the only way in which this can fail is if a client tries to
draw its own decorations (or something) “outside” of their own window,
assuming that origin+width or origin+height actually brings them there
in the root context (I mean as opposed to using XTranslateCoords,
which can be handled from within the server).

> I'm wondering if there are others who would find this useful, and if
> some of them might help get this into reasonable shape. Suggestions are
> welcome!

This sounds like an excellent solution to improve Hi- and most
importantly mixed-DPI setups. I'm a bit swamped for the next month,
but after that I can at the very least help test and debug the code,
since I have multiple such setups. One thing that would definitely be
useful for the mixed DPI case is some way to more or less
automatically change the scaling factor based on window location (or
at least Monitor it belongs to), at least in the case where the X
server itself is doing the compositing.

Giuseppe "Oblomov" Bilotta

More information about the xorg-devel mailing list