Any plan to promote coordinats to 32 bits?

Glynn Clements glynn at
Tue Nov 23 05:01:59 PST 2010

Teika Kazura wrote:

> X coordinates are 16 bits, but are there any plan to promote them
> to 32 bits? I couldn't find one in the Xorg site.
> In fact, 16 bits are not sufficient these days. If you have
> several screens and enlarge your desktop with a window manager
> to several X screens width / height, it can easily exceed 32767.

No, it can't exceed 32767; you might /want/ to exceed that, but that's
a different matter.

> Is this fact known to X developement society?

Yes. E.g. if you want to create a viewport on a much larger "canvas",
you can't just create a child window the size of the canvas and scroll
by changing its (parent-relative) position. You have to implement
transformation and clipping yourself.

The limitations on the core X protocol aren't likely to change; it
would cause too much breakage. For graphics, you can just use Render,
cairo, OpenGL, etc. I don't think that the 16-bit limitation on the
size of a window is likely to be a problem for the foreseeable future
(apart from anything else, you're likely to run into memory issues
with backing store or compositing buffers before that). If you want
large virtual desktops, the WM just needs to be creative.

Glynn Clements <glynn at>

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