Feature request: controlling the display white point

[Andrew Lutomirski <andy luto us>]

One thing that's bugged my about both ArgyllCMS and g-c-m is that it's
hard to set the target white point for the display.  There are a few
reasons I'd want to be able to do this:

1. If the dislpay has a strange native white point, I might want to
calibrate and profile to preserve something close to the native white
point.

2. Some rooms are different colors.  For comfort using the display,
I'd like the white point to look natural in the room I'm in.

3. There are programs like f.lux [1] that vary the white point
throughout the day.  I should be able to do this using tools like
g-c-m.


Would it make sense for ArgyllCMS and/or g-c-m to have better white
point control?  Ideally I'd be able to profile my display once
(possibly in a slower mode that collected more data points) and then,
whenever I want to set a white point, to generate the gamma ramp and
profile for that white point on the fly.  From the colord/g-c-m point
of view, being able to go into the g-c-m settings and select a white
point for immediate application would be nice (and programs like f.lux
could be replaced by some straightforward code to ask g-c-m or colord
to change the white point).


[1] http://justgetflux.com/ -- AFAICT the control / GUI source is
available (no license) and the daemon is a binary blob.  I doubt that
the daemon does anything very interesting right now, though.

--Andy