[Openicc] ICC Profiles in X Specification 0.4

[Richard Hughes]

On 24 March 2010 08:11, Kai-Uwe Behrmann <ku.b at gmx.de> wrote:
> However I think we would add already complexity by using the per output atom
> as the spec has already the per root window ones.

Sure, but you only used the root window because XRandR didn't exist
when the spec was started. Now it seems a crying shame not to use a
new framework designed for this kind of per-output setting, in a new
standard (_ICC_DEVICE_PROFILE_xxx) that nothing supports yet.

> I see adding XRandR at the moment as
> redundant, when we need root atoms anyway in the spec.

I see adding an arbitrary suffix to X atoms and putting it in the root
window to be redundant. XRandR is the future,  it's not going away.
Xinerama is however, going away.

> Again, we do not create a spec from scratch. The 0.1 version is already
> widely adopted and used. I guess the following versions are as well. So if
> we break existing applications, user will blame us. And IMHO they would be
> right in doing so.

Sure, the _ICC_PROFILE stays on the root window, it would be madness
to change that. _ICC_PROFILE specifies what the color aware
applications render to, which is either the monitor profile, or some
arbitrary space like sRGB. Applications don't change. Applications
don't have to read the XRandR properties, as this will be the job of
the late-color bound color manager, e.g. compiz.

> _ICC_DEVICE_PROFILE by the colour server at run time. Apps supporting the
> per window region communication can use that _ICC_DEVICE_PROFILE atom(s).

I don't think that makes sense at all.

> Agreed, these two later atoms are not much thought out. Perhaps colour
> servers can communicate switching just by property notification of the
> _NET_COLOR_DESKTOP atom containing the new colour servers pid. That later
> atom can be interpreted that a colour server wants to take over the service.
> This would obsolete the _ICC_PROFILE_SETUP* atoms sections.

Sure, I though all the _ICC_PROFILE_SETUP* atoms were completely
redundant to be honest.

Richard.