More HDR Preparations Merged In Time For GNOME 47

Following the recent Mutter 47 beta release that also marks the feature freze point for GNOME 47, there still are some High Dynamic Range (HDR) display preparations being merged ahead of this next stable desktop release due out in September.

Hitting Mutter Git today is this merge request for MetaColorDevice/Manager to track the color state of monitors and be able to apply calibrations. Developer Sebastian Wick explained in that merge:

"Another prep MR for the HDR and color management MR.

This time we expand the usage of the MetaColorDevice. The lifetime had to change a bit so it can stay around as long as the monitors do. It takes over applying the calibration (KMS Colorspace and HDR_OUTPUT_METADATA props) and derives the resulting ClutterColorState."

The 15 now merged patches allow reading the temperature from the manager, applying HDR and color-space calibration, and related preparations as GNOME developers work to ultimately deliver a nice Linux HDR desktop experience.

Not yet merged but tagged for the GNOME 47 milestone is also this merge request opened three weeks ago by Jonas Ådahl. That code makes SDR white luminance variable rather than hard-coded and adding an HDR brightness factor.

Those wishing to track the overall and ongoing progress of HDR for GNOME's Mutter can see Draft: HDR support in Mutter. If 2024 was the year of the Wayland Linux desktop, perhaps 2025 will finally see the culmination of HDR on the Linux desktop?