To support fractional scaling, change the stage view scale to be a
float instead of an int. Also change the places where it is retrieved
and used when scaling things.
https://bugzilla.gnome.org/show_bug.cgi?id=765011
Make the nested backend emulate how the real backends actually draw,
i.e. by drawing each CRTC separately. This makes it possible to test
different configuration paths that can take place on different
hardware, without having said hardware.
For example, by setting MUTTER_DEBUG_TILED_DUMMY_MONITORS and
MUTTER_DEBUG_NESTED_OFFSCREEN_TRANSFORM to "1", one can test a system
with MST (tiled) monitors where the GPU doesn't support some transform.
https://bugzilla.gnome.org/show_bug.cgi?id=777732
Always draw the stage to an offscreen framebuffer when using the nested
backend, so that we more emulate things more similarly to how it works
real-world, i.e. it'll work the way whether stage views are enabled or
not.
https://bugzilla.gnome.org/show_bug.cgi?id=777732
Keep track of the logical monitor transform. When a logical monitor is
transformed, all of its monitors are also transformed in the same way.
A logical monitor can either be transformed on the CRTC level, or using
an offscreen intermediate buffer. In both cases will the logical
monitor be transformed, but only in the latter will the view be
transformed.
MetaCrtcs::transform currently does not represent whether the CRTC is
configured to be transformed or not; only when the backend can handle
it does it correctly correspond to the actual CRTC configuration. This
is intended to change with MetaMonitorConfigManager.
https://bugzilla.gnome.org/show_bug.cgi?id=777732
Split up the MetaRendererX11 class into one for when running as a
X11 compositing manager, and one for when running as a nested Wayland
compositor.
https://bugzilla.gnome.org/show_bug.cgi?id=777732
