FR-DSP-8's acquisition half. `dr_plat::display` surveys the session's
displays and reduces each one's profile to an output space the pipeline
can encode into, stating the mechanism per display server as
FR-PLAT-LIN-2 requires:
- X11 reads the `_ICC_PROFILE` / `_ICC_PROFILE_<n>` root-window
properties, enumerating and numbering the outputs through RandR,
which also yields the rectangles a window move is measured against.
- Wayland binds `wp_color_manager_v1` and asks each `wl_output` for
its image description, accepting either an ICC profile on a file
descriptor or primaries stated as chromaticities.
- Where neither answers, sRGB is assumed and the reason travels with
it as data rather than into a log, so the About page can say which
path the session is on.
A display profile is a measurement of one panel and is none of the four
spaces the pipeline knows. Rather than grow an ICC engine, the profile
is reduced to D50-adapted colorants and matched against the four; a
match that is merely nearest is marked as such and shown as such.
Verified on this machine: mutter 50 advertises the colour-management
global and reports eDP-1 as sRGB, and the same session forced onto X11
enumerates the output through RandR and correctly finds no atom.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>