[RFC wayland-protocols] Color management protocol

[Kai-Uwe]

Am 14.01.2017 um 03:24 schrieb Carsten Haitzler (The Rasterman):
> On Fri, 13 Jan 2017 18:08:51 +0200 Pekka Paalanen <ppaalanen at gmail.com> said:
>> Oh, ok, that's why. We could as easily have the compositor show the
>> color swatch only on a part of the output and leave the rest of the
>> area for normal use.
>>
>> However, if that is done with a special protocol so that the compositor
>> actually knows this is the profiling color swatch, it can make sure
>> other windows cannot interfere. It could be like the color swatch was
>> on an always-on-top overlay. You cannot do that any other way from a
>> Wayland client.
>>
>> And if unform color for the swatch is all you need, the protocol could
>> simply take 3 numbers for the color instead of an image buffer. Then
>> people would not get the urge to abuse this interface for e.g.
>> application splash screens.
> 
> i kind of like the idea of a special protocol with 32bit ints per rgb etc. to
> say "display this exact uncalibrated color as-is without luts or anything else
> in the way"... but apply it to a separate toplevel window/surface (and put your
> guided ui controls in another window) or... use a subsurface.

+1 for subsurface. The compositor can even take over responsibility to
move the belonging window to the desired output, for the case the
underlying application can not manage or handle that itself (e.g. for
mirrored outputs).