The following implicit definition for `transform()` did not
correctly apply:
```
a * b = c
c * invert(b) = a
```
Crucially the following did not apply for `FLIPPED-90`
and `FLIPPED-270`:
```
a * invert(a) = identity
```
Fix this by applying the operations, first the flip, then the
rotation, in this order and add tests to ensure correct results
for the requirement above.
Also drop `relative_transform()` as it only had a single user and
can be replaced by `transform()`:
```
invert(a) * b = c
a * c = b
```
As this is not very intuitive, ensure in tests as well.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2459>
Now set as a property during construction. Only actually set by the
Xrandr backend, as it's the only one currently not supporting all
transforms, which is the default.
While at it, move the 'ALL_TRANFORMS' macro to meta-monitor-tranforms.h.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
Commit e06daa58c3 changed the tested values to use corresponding valid
enum values instead of negative ones. Unfortunately that made one value
become a duplicate of an existing one and also in part defeated the original
intention of checking the implementation of
`meta_output_crtc_to_logical_transform`.
Use `meta_monitor_transform_invert` to fix both shortcomings.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1242
A plane is one of three possible: primary, overlay and cursor. Each
plane can have various properties, such as possible rotations, formats
etc. Each plane can also be used with a set of CRTCs.
A primary plane is the "backdrop" of a CRTC, i.e. the primary output for
the composited frame that covers the whole CRTC. In general, mutter
composites to a stage view frame onto a framebuffer that is then put on
the primary plane.
An overlay plane is a rectangular area that can be displayed on top of
the primary plane. Eventually it will be used to place non-fullscreen
surfaces, potentially avoiding stage redraws.
A cursor plane is a plane placed on top of all the other planes, usually
used to put the mouse cursor sprite.
Initially, we only fetch the rotation properties, and we so far
blacklist all rotations except ones that ends up with the same
dimensions as with no rotations. This is because non-180° rotations
doesn't work yet due to incorrect buffer modifiers. To make it possible
to use non-180° rotations, changes necessary include among other things
finding compatible modifiers using atomic modesetting. Until then,
simply blacklist the ones we know doesn't work.
https://gitlab.gnome.org/GNOME/mutter/issues/548https://gitlab.gnome.org/GNOME/mutter/merge_requests/525
