As it was originally reported on
https://bugzilla.gnome.org/show_bug.cgi?id=779234#c0, the hottest path was
convert_ubyte() in mesa. Reverting this shows no trace of those hot paths,
nor any higher than usual CPU activity.
As the improvements at the time were real, I can only conclude that pixel
conversion was happening somewhere further the pipeline, and swizzling just
helped indirectly. That got eventually fixed, so swizzling just stayed to
cause grief. And lots it caused.
Time to bin this, it seems.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/486
This basically reverts commit 54735dec, which tried to avoid the
GLib-defined types in favor the standard C ones. One exception to this
is the bool type, for which the commit introduces a new type CoglBool.
Let's just get rid of this type in favor of having consistency with the
GLib types. Note by the way that neither CoglBool nor gboolean (which
has a size of `int`) are completely compatible with bool (size `char`).
https://gitlab.gnome.org/GNOME/mutter/merge_requests/321
This is used by the GL driver in order to determine whether swizzling
actually applies given the bitmap and target texture internal format.
If both agree that they store BGRA, then swizzling may apply.
https://bugzilla.gnome.org/show_bug.cgi?id=779234
