CoglJournal tracks a few OpenGL states so that they can
be batch-applied if necessary. It also has a nice property
of allowing purely CPU-based glReadPixels() when the scene
is composed of simple rectangles.
However, the current journal implementation leaves various
other GL states out, such as dithering and the viewport.
In Clutter, that causes the journal to be flushed when
picking, touching the GPU when we didn't really need to.
Track the viewport of the framebuffer in the journal so that
we can avoid flushing the journal so often.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/402
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
