This mocks gsd-colord to enable night ligth at a given temperature. The
test then verifies that the result exactly matches that of the gamma
ramps gsd-color generated for the same temperature and ICC profile.
There are two types of profiles tested; ones with VCGT, i.e. calibrated
profiles, and ones without. These are tested as the VCGT affects how the
gamma curve looks, while the non-VCGT profiles all only rely on
the blackbody temperature to generate a gamma ramp.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2165>
We created device profiles, that we manage the lifetime of in colord,
but color devices can be assigned profiles other than the ones it was
created for. For example, this can include the standard sRGB profile
provided by colord.
To achieve this, keep track of the default profile of the CdDevice as
the "assigned" color profile of the device. Given this profile
(CdProfile), construct a MetaColorProfile that can then be interacted
with as if it was generated by ourself.
The assigned profile (default profile in colord terms) does nothing
special so far, but will later be used to determine how to apply CRTC
gamma ramps etc.
The sRGB.icc file used in the tests was copied from colord. It was
stated in the repository that it has no known copyright restrictions.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2164>