fcbd2e3840
This TF can't be defined as a TransferFunction enum because it needs a gamma_exp value too. Add to EOTFType enum a new type: EOTF_TYPE_GAMMA. With this new type, now EOTFs are unions that can have either a TransferFunction enum or a gamma_exp. Set gamma_exp as uniform. Add the support of it in the color management protocol. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4020>