In case the shell ignores or can't accept the restart request we should
hide the message that has been just requested to be shown.
As per ::show-restart-message signal documentation, this has to be done by
emitting the signal with a NULL message.
So follow the API properly in such case
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1780>
In non-systemd managed session we are unable to start services on
demand. Instead, gnome-session will start everything at login time,
including any X11 related service (i.e. gsd-xsettings).
However, in order to start gsd-xsettings, Xwayland needs to be started
already. Otherwise it will connect to GNOME_SETUP_DISPLAY and login will
hang at that point.
Fix this by detecting whether mutter is running in a systemd unit. If it
is, we assume that we are systemd managed and the machinery to start the
services works fine. If not, we assume that the session management may
unconditionally try to start X11 related services and Xwayland must be
started in order to not block this.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1771>
On Wayland MetaInputSettings is part of the input thread. Connecting
a GSettings binding to the default ClutterSettings could result in the
change notification being emitted on the input thread. This then could
end up triggering the same handler from two different threads at the
same time. In the case of the ClutterText layout cache it was attempting
to unref the same layout twice, leading to a crash.
This can be avoided by simply removing the GSettings bind. This does not
cause changes to this setting to be missed by ClutterSettings because it
itself already sets up a bind.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1696
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1776>
When deciding if `configure` event should be sent,
`meta_window_wayland_move_resize_internal` compares requested window size
with `window->rect` size. However, `window->rect` is only updated when `commit`
is received. So the following sequence produces incorrect result:
1. a window initially has size `size1`
2. `move_resize_internal` is called with `size2`. `configure` is sent
3. `move_resize_internal` is called with `size1` to restore original size,
but `commit` for `size2` haven't arrived yet. So `window->rect` still has size
`size1`, and thus new `configure` is not sent
4. `commit` for `size2` arrives, window changes size to `size2`
Expected window size in the end: `size1`
Actual: `size2`
To fix the issue, take size from pending `configure` events into account.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1627
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1755>
This eliminates the need for any render node or device nodes, thus can
be used without any graphics hardware available at all, or with a
graphics driver without any render node available.
The surfaceless mode currently requires EGL_KHR_no_config_context to
configure the initial EGL display.
This also means we can enable the native backend tests in CI, as it
should work without any additional privileges.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
Tests that creating and starting a virtual screen cast monitor works,
and that at least one one buffer is processed.
Currently the content of the buffer isn't checked more than it can be
mmap():ed. Only MemFd buffers are tested for for now, as DMA buffers
would need a surfaceless EGL context to check properly.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
The new RecordVirtual API creates a virtual monitor, i.e. a region of
the stage that isn't backed by real monitor hardware. It's intended to
be used by e.g. network screens on active sessions, virtual remote
desktop screens when running headless, and scenarios like that.
A major difference between the current Record* API's is that
RecordVirtual relies on PipeWire itself to negotiate the refresh rate
and size, as it can't rely on any existing monitor, for those details.
This also means that the virtual monitor is not created until the stream
negotiation has finished and a virtual monitor resolution has been
determined.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
The area source, window source, and monitor source, currently set up the
stream size up front, given the area, maximum allowed window size or
monitor resolution, but for to be introduced sources, the size will be
negotiated using PipeWire, instead of specified via the D-Bus API. This
commit changes the internal source API to allow for this. There are
currently no users of this new behaviour.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
There may be a race between the ability to turn stream relative input
coordinates and turning them into screen coordinates, due to the future
scenario where the entity backing a stream is created and managed ad-hoc
depending on PipeWire stream negotiations.
When an input event is sent during this time, drop it.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
Make it possible to create persintent virtual monitors using command
line argument. This will not be the only way to create virtual monitors,
the primary way will be using the screen cast API, but using command
line argumenst is convenient for debugging purposes.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
The testing currently done is:
* Creating a virtual monitor succeeds and gets the right configuration
* Painting a few times results in the expected output
* Changing the content of the stage also changes the painted content
accordingly
* Destroying the virtual monitor works as expected
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
This adds a test framework that makes it possible to compare the result
of painting a view against a reference image. Test reference as PNG
images are stored in src/tests/ref-tests/.
Reference images needs to be created for testing to be able to succeed.
Adding a test reference image is done using the
`MUTTER_REF_TEST_UPDATE` environment variable. See meta-ref-test.c for
details.
The image comparison code is largely based on the reference image test
framework in weston; see meta-ref-test.c for details.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
Virtual monitors are monitors that isn't backed by any monitor like
hardware. It would typically be backed by e.g. a remote desktop service,
or a network display.
It is currently only supported by the native backend, and whether the
X11 backend will ever see virtual monitors is an open question. This
rest of this commit message describes how it works under the native
backend.
Each virutal monitor consists of virtualized mode setting components:
* A virtual CRTC mode (MetaCrtcModeVirtual)
* A virtual CRTC (MetaCrtcVirtual)
* A virtual connector (MetaOutputVirtual)
In difference to the corresponding mode setting objects that represents
KMS objects, the virtual ones isn't directly tied to a MetaGpu, other
than the CoglFramebuffer being part of the GPU context of the primary
GPU, which is the case for all monitors no matter what GPU they are
connected to. Part of the reason for this is that a MetaGpu in practice
represents a mode setting device, and its CRTCs and outputs, are all
backed by real mode setting objects, while a virtual monitor is only
backed by a framebuffer that is tied to the primary GPU. Maybe this will
be reevaluated in the future, but since a virtual monitor is not tied to
any GPU currently, so is the case for the virtual mode setting objects.
The native rendering backend, including the cursor renderer, is adapted
to handle the situation where a CRTC does not have a GPU associated with
it; this in practice means that it e.g. will not try to upload HW cursor
buffers when the cursor is only on a virtual monitor. The same applies
to the native renderer, which is made to avoid creating
MetaOnscreenNative for views that are backed by virtual CRTCs, as well
as to avoid trying to mode set on such views.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
The order of which function argument expressions are executed is
undefined, so don't rely on this for setting the background colors, as
it results in different colors on different architectures.
For example, it has been observed that the order of execution is
reversed comparing x86_64 and aarch64, making these two architectures
having different background color.
Fix this confusion, and also reproduceability in future reference tests,
by making the order of execution predictable.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
It's useful to be able to have very very tiny monitors (e.g. 60x60
pixels) when doing reference testing, as tests have reference images
that the output is compared to. Smaller reference images the less
storage they use.
To avoid annoying pointless warnings when this is done, change the
pedantic workspace work area code to be more forgiving if the work area
happens to match the display size.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
When rebuilding the monitors (e.g. during hotplug), make sure to detach
the disposed monitors from any outputs before creating the new monitors.
While this isn't currently needed, as outputs are too being recreated,
with the to be introduced virtual outputs that are created for virtual
monitors, this is not always the case anymore, as these virtual outputs
are not regenerated each time anything changes.
Prepare for this by making sure that cleaning up disposed monitors
detach themself properly from the outputs, so new ones can attach
themself to outputs without running into conflicts.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
This makes it possible to pass custom properties to backends when
constructing tests. This will be used to create "headless" native
backend instances for testing the headless native backend.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
With this commit, it's possible to run mutter without being DRM master.
It's not yet possible to add virtual monitors, but one can for example
already add virtual input devices.
This currently doesn't try to hook up to any logind session, thus will
not have a real seat assigned. Currently it's hard coded to "seat0".
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
Currently our only entry point for DRM devices is MetaKms*, but in order
to run without being DRM master, we cannot use /dev/dri/card*, nor can
we be either of the existing MetaKmsImplDevice implementation (legacy
KMS, and atomic KMS), as they both depend on being DRM master.
Thus to handle running without being DRM master (i.e. headless), add a
"dummy" MetaKmsImplDevice implementation, that doesn't do any mode
setting at all, and that switches to operate on the render node, instead
of the card node itself.
This means we still use the same GBM code paths as the regular native
backend paths, except we never make use of any CRTC backed onscreen
framebuffers.
Eventually, this "dummy" MetaKmsImplDevice will be replaced separating
"KMS" device objects from "render" device objects, but that will require
more significant changes. It will, however, be necessary for e.g. going
from being headless, only having access to a render node, to turning
into a real session, with a seat, being DRM master, and having access to
a card node.
This is currently not hooked up, but will be in a later commit.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
Add a flag to MetaSeatNative and MetaSeatImpl that tells it not to
attempt to create a libinput context. This is intended to be used when
mutter is to run headless, as in without any input devices other than
virtual ones.
Currently not hooked up.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
This leaves only the atomic mode setting cap check before creating the
impl device, aiming to make it possible to create a non-mode-setting
MetaKmsImplDevice implementation.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
Make it possible to pass --headless as a command line argument in order
to turn the native backend "headless". This currently doesn't do
anything, but the intention is that it should not use logind nor KMS,
and work completely headless with only virtual outputs.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
Input settings requires a valid seat in order to initialize the a11y
settings (since commit 1609d145), however in X11 we never set it and
even if we create the input settings early (as per commit 7547891a) we
never initialize the seat for it.
This leads to startup critical errors on X11:
clutter_seat_get_pointer_a11y_settings: assertion
'CLUTTER_IS_SEAT (seat)' failed
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1763>
This commit adds the events created in the function
`meta_seat_x11_notify_devices` to the clutter events queue, which
are currently only added to the stage queue making the events not
being picked up by the `clutter_seat_handle_event_post` function.
This results in devices not getting added to the device-list of
`MetaInputSettings`.
Fixes the bug in which mouse and touchpad settings are not working in
the settings app during x11 session.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1767>
Since commit 2ceac4a device-related X11 events aren't processed anymore,
causing the input settings not to handle the devices.
This is due to the fact that we may never call clutter_seat_handle_event_post()
for such events.
While this is always happening for the native backend, it doesn't happen in
X11 because the events are removed from the queue as part of
meta_x11_handle_event(), and thus no event was queued to the stage by the
backend events source.
This also makes sure that the event post handler is called after the
event is actually processed, and not before an event is queued.
Fixes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1564
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1769>
The nested backend may need to have an input setting implementation,
while we don't want to change the host settings (re-using an X11 input
settings) we can add a dummy implementation, until something more
complex is needed.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1769>
The sync ring has an API about "frames", where it is notified about
the end of frames. However, its "insert wait" call is done before
updates, meaning that some "insert waits" will never see the "after
frame" if there was no frame drawn. This will cause mismatching in the
frame counting, causing freezes in the synchronization until something
else triggers an actual frame, effectively "unfreezing" the sync ring.
Fix this by not only notifying the sync ring about frames when there
were actual frames drawn, but also on plain updates which didn't result
in a drawn frame.
Related: https://gitlab.gnome.org/GNOME/mutter/-/issues/1516
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1754>
When a gtk theme uses larger shadows for the unfocused state than for
the focused one, this can cause a crash in meta_frame_left_click_event.
Since whether to call meta_frame_left_click_event is decided based on
the decoration size before focusing and the control that was clicked on
after focusing, this can result in an event handled in
meta_frame_left_click_event being on the client area.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1668
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1748>
With commit 7d78768809 we switched to
storing pointer coordinates in MetaInputDeviceNative instead of
ClutterInputDevice, and while we had set the coordinates of the
ClutterInputDevice in ClutterStage when queueing an event, we now set
the MetaInputDeviceNative coordinates in new_absolute_motion_event().
Here a small mistake snuck in: new_absolute_motion_event() only
translates the coordinates of the event, but we call
meta_input_device_native_set_coords() using the x and y variables
(which remain untranslated), so now the input device coordinates are no
longer translated.
Fix that by translating the coordinates of the x and y variables in case
we're we handling a tablet/stylus event instead of only translating the
event coordinates.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1685
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1760>
This fixes the interpolate test to not use the wall clock, but the
monotonic clock. It also cleans up the timestamp granularity naming, so
that the different granularity is clearer, as in the test, different
timestamps have different granularity.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1751>
This more or less rewrites this test so that it explicitly tests the
"interpolation" when a timeline loops, i.e. that if something occupies
the thread when a timeline was supposed to have looped, we end up in the
right place "in the middle" of the next timeline cycle.
The test more or less does this:
* Start a 3 second looping timeline
* Sleep so that we're in the middle of the first cycle
* Sleep again so that we end up in the middle of the next cycle
The semantics checked are that we see the following frames:
* The first frame with timestamp 0
* The second frame in the middle of the first cycle (timestamp ~= 1.5
sceonds)
* The third frame in the end of the first cycle (timestamp == 3.0
seconds)
* The fourth frame, first in the second cycle, with timestamp ~= 1.5
seconds)
This means we can increase the "grace period" to the double (from 0.5 s
to 1 s), while at the same time decrease the time spent running the test
(from 10 s to 4.5 s). This should hopefully make the test less flaky,
especially in slower runners, e.g. aarch64.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1751>
With commit c985753442 the support for
multiple hardware cursors broke, but those were never properly supported
anyway as we usually assume there's only one hardware cursor around.
With the introduction of the KMS thread in the future, we'll only have
one KMS cursor that gets updated directly from the input thread. So
apart from the fact that it never really makes sense to have two cursors
visible, in this new model having multiple cursors won't work anyway.
So make the cursor we show for stylii a software cursor again.
Eventually the plan is to make the input device that's driving the KMS
cursor interchangeable, so that we can always use hardware cursors.
This reverts commit 165b7369c8.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1645
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1758>
This commit assumes that cursor surfaces work in a "mailbox" fashion. If
they are painted multiple times before a successful flip, all commits
but the last get discarded, and the last commit gets presented after the
flip succeeds. This is more or less how it works in the atomic backend,
and also more or less how it works in other backends, with the exception
that the cursor painting might fail without any way of knowing. This
assumption is still better than unconditionally discarding all cursor
surface feedbacks as if the cursor painting always fails.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1484>
Regarding the sequence = 0 fallback: in some cases (moving a cursor
plane on atomic amdgpu) we get sequence = 0 in the page flip callback.
This seems like an amdgpu bug, so work around it by assuming a sequence
delta of 1 (it is equal to 1 because of the sequence != 0 check above).
Sequence can also legitimately be 0 if we're lucky during the 32-bit
overflow, in which case assuming a delta of 1 will give more or less
reasonable values on this and next presentation, after which it'll be
back to normal.
Sequence is also 0 on mode set fallback and when running nested, in
which case assuming a delta of 1 every frame is the best we can do.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1484>
The presentation-time protocol allows surfaces to get accurate
timestamps of when their contents were shown on screen.
This commit implements a stub version of the protocol which correctly
discards all presentation feedback objects (as if the surface contents
are never shown on screen). Subsequent commits will implement sending
the presented events to surfaces shown on screen.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1484>
This concerns only the cases when the presentation timestamp is received
directly from the device (from KMS or from GLX). In the majority of
cases this timestamp is already MONOTONIC. When it isn't, after this
commit, the current value of the MONOTONIC clock is sampled instead.
The alternative is to store the clock id alongside the timestamp, with
possible values of MONOTONIC, REALTIME (from KMS) and GETTIMEOFDAY (from
GLX; this might be the same as REALTIME, I'm not sure), and then
"convert" the timestamp to MONOTONIC when needed. An example of such a
conversion was done in compositor.c (removed in this commit). It would
also be needed for the presentation-time Wayland protocol. However, it
seems that the vast majority of up-to-date systems are using MONOTONIC
anyway, making this effort not justified.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1484>
KMS and GLX device timestamps have microsecond precision, and whenever
we sample the time ourselves it's not the real presentation time anyway,
so nanosecond precision for that case is unnecessary.
The presentation timestamp in ClutterFrameInfo is in microseconds, too,
so this commit makes them have the same precision.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1484>
A flag indicating whether the presentation timestamp was provided by
the display hardware (rather than sampled in user space).
It will be used for the presentation-time Wayland protocol.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1484>
A flag indicating whether the presentation timestamp was provided by the
display hardware (rather than sampled in user space).
It will be used for the presentation-time Wayland protocol.
This is definitely the case for page_flip_handler(), and I'm assuming
this is also the case for the two instances in the GLX code.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1484>
The old calculation was introduced to improve the precision
with commit c16a5ec1cf.
Here, I call the calculation as "revision 2", and the
calculation even older as "revision 1", and the new
calculation introduced with this commit as "reivion 3".
Revision 2 has two problems:
1. The calculation is mixed with fixed-point numbers and
floating-point numbers.
To overcome the precision loss of fixed-point numbers division,
it first "calculates refresh rate in milliHz first for extra
precision", but this requires converting the value back to Hz.
An extra calculation has performance and precision costs.
It is also hard to understand for programmers.
2. The calculation has a bias.
In the process, it does:
refresh += (drm_mode->vtotal / 2);
It prevents the value from being rounded to a smaller value in
a fixed-point integer arithmetics, but it only adds a small
bias (0.0005) and consumes some fraction bits for
floating point arithmetic.
Revision 3, introduced with this commit always uses
double-precision floating-point values for true precision and
to ease understanding of this code. It also removes the bias.
Another change is that it now has two internal values, numerator
and denominator. Revision 1 also calculated those two values
first, and later performed a division with them, which minimizes
the precision loss caused by divisions. This method has risks of
overflowing the two values and revision 1 caused problems due to
that, but revision 3 won't thanks to double-precision. Therefore,
revision 3 will theoretically have the result identical with
the calculation with infinite-precision.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1737>
Handle the case of a TOUCH_BEGIN event during window dragging separately
instead of treating it like a TOUCH_UPDATE event: Simply return TRUE to
make Clutter stop event propagation if it's the pointer emulating
sequence and let Clutter propagate the event if it isn't.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/427>
Window dragging should be cancelled when the touch sequences we're using
are no longer available. Also listen to TOUCH_CANCEL events if the
window is grabbed and cancel the grab op when a TOUCH_CANCEL event
happens.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/427>
This removes the responsibility of tracking these from the backend to
the base object. The backends are instead responsible for calling the
function to update the values.
For the native backend, it's important that this happens on the correct
thread, so each time either of these states may change, post a idle
callback on the main thread that sets the, at the time of queuing said
callback, up to date state. This means that things on the main thread
will always be able to get a "new enough but not too new" state when
listening on the 'notify::' signals and getting the property value
after.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1739>
Make sure to reset all the state that was set for an interactive grab op
back to the defaults after a grab op has ended.
Especially important here is setting grab_frame_action back to FALSE,
since this will constrain window-titlebars to the panel. We set this to
TRUE on some grabs, for example when resizing, but not when moving
windows. Since this remained being set to TRUE, it would also constrain
non-grab window movements, like calling MetaWindow.move_frame(), which
is used by gnome-shells OSK. By resetting it back to FALSE after a grab,
the OSK can now always move non-maximized windows to the position it
wants.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1736>
The cache had the size 9, which was "big enough" in the past, but when
more ways pipelines could be constructed, the size was not enough. The
need to increase the cache size was hard to spot though, since adding
pipeline flag didn't give any hints about the cache being directly tied
to these flag values.
So, when enough flag bits were set when attempting to retrieve and put a
pipeline in the cache, it'd instead overwrite some arbitrary stack
memory, which would sooner or later result in a memory corruption
induced crash. Valgrind could not detect this particular memory
corruption, as it messed up stack memory, not e.g. freed heap memory, so
it instead got confused and thought plain stack values were unreadable.
Fix these two issues by making the cache size the combination of all
pipeline flags + 1, so that we can safely put any flag combination in
the cache.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1747>
If `meta_xwayland_start_xserver()` returned via an error path, some of
the socket FDs were leaked.
Fix that, and add `steal_fd()` calls to make it clearer that FDs passed
to `g_subprocess_launcher_take_fd()` are transferred to it. There were
no bugs with how `GSubprocessLauncher` was being used.
Spotted while working on
https://gitlab.gnome.org/GNOME/glib/-/issues/2332.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1738>
Each next and current scanout buffer has a reference on them making sure
they stay alive. When dumb buffers were used on the secondary GPU state,
this didn't happen, leading to crashes due to unref:ing one time too
many, with backtraces such as
0) g_type_check_instance_is_fundamentally_a ()
1) g_object_unref ()
2) secondary_gpu_release_dumb ()
3) import_shared_framebuffer ()
4) update_secondary_gpu_state_post_swap_buffers ()
5) meta_onscreen_native_swap_buffers_with_damage ()
6) cogl_onscreen_swap_buffers_with_damage ()
7) swap_framebuffer ()
8) clutter_stage_cogl_redraw_view_primary ()
9) clutter_stage_cogl_redraw_view ()
10) _clutter_stage_window_redraw_view ()
11) handle_frame_clock_frame ()
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1746>
gnome-shell has this hack where it sets the environment variable
"NO_AT_BRIDGE" to "1" before calling meta_init() and then unsets it
after meta_init() returns.
This variable being set to "1" will then cause the ATK bridge in
at-spi2-gtk to fail to load, which GTK then ignores. This is on purpose,
since accessibility is supposed to be done done by GNOME Shell via
Clutter, not via GTK.
The problem is that, now, by default, setting "NO_AT_BRIDGE" to
"1" during meta_init() only has the desired effect on an X11 session,
where we always connect to the X11 server on startup (i.e. during
meta_init()). With Xwayland on-demand, we do not attempt to create the
GDK display during meta_init(), thus this hack falls apart.
Since there are no real altenatives to this hack, just move it to
mutter, which have a better idea when GDK displays are created or not.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1744>
Commit afa43154 tried to make sure the focus was properly changed when
calling focus_default_window() by checking the focused window just after
trying to set the focus.
However, the X11 “Inter-Client Communication Conventions Manual” version
2.0 (ICCCM 2 for short) states that some X11 client may want to use a so
called “globally active input” model in which case the client expects
keyboard input and set input focus even when it's not one of its own
window.
To comply with this, when dealing with such clients, mutter will not
change the focus and send a WM_TAKE_FOCUS message instead.
That mechanism will defeat the logic introduced by commit afa43154
because the focused window is not changed in this case. As a result, the
input focus will fallback to the no-focus window.
To avoid this, only check that the focus change occurred for windows
using a synchronous focus model.
v2: Split specific test for "globally active input" model (Florian).
v3: Remove the check for window->unmanaging which is useless (Jonas).
Fixes: afa43154 - "core: Make sure focus_default_window() worked"
Close: https://gitlab.gnome.org/GNOME/mutter/-/issues/1620
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1716>
X11 clients can use different models of input handling, of which some
may not result focus being set synchronously.
For such clients, meta_focus_window() will not change the focus itself
but rely on the client itself to set the input focus on the desired
window.
Add a new MetaWindow API to check when dealing with such a window.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1716>
Without these devices, things that depend on the existance of input
device classes won't know about the existance of e.g. pointer devices,
if the only pointer device is from a virtual one.
This requires handling situations where e.g. a device doesn't have a
device node thus can't be matched against a udev device.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1688>
Libinput will queue a few initial events when a seat is assigned to the
udev backend; a result of it probing udev adding detected devices. For
us to see these events, we need to dispatch libinput before going idle,
as nothing will show up on the libinput file descriptor until something
else (e.g. keyboard event or mouse movement) wakes us up.
Do this by adding a prepare() function to the libinput GSource, that
checks whether there are any events in the queue already, and return
TRUE if so is the case, causing us to dispatch before going fully idle.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1688>
The API for NotifyKeyboardKeycode() does not mention what type of
keycode is expected to be submitted.
So, clarify in the API that the keycode to submit is expected to be an
evdev keycode.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1732>
Currently, when a remote desktop user submits a keycode, it will be
interpreted differently, when using the x11 session, instead of a
wayland session.
In a wayland session, submitting a keycode will have the expected
result (as if the key was pressed locally).
In a x11 session, this is not the case. Instead of getting the expected
key, some other key will be pressed (or sometimes even none).
The reason for this is that the native backend interprets the keycode
as evdev keycode and the x11 backend interprets the keycode as xkb
keycode.
To ensure that both backends produce the same behaviour when submitting
a keycode, fix the x11 backend to always interpret the keycode as evdev
keycode, instead of a xkb keycode.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1732>
GObject signals pass the emitting GObject as the first argument to
signal handler callbacks. When refactoring the grab-op-begin/end signals
to remove MetaScreen with commit 1d5e37050d,
the "screen" argument was replaced with a "display" argument instead of
being removed completely. This made us call the signal handlers with two
identical MetaDisplay arguments, which is very confusing and actually
wasn't handled in a grab-op-begin handler in gnome-shell.
So fix this by not adding the MetaDisplay as an argument to those
signals, GObject will take care of that for us.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1734>
We're going to round the workspace backgrounds in the new overview for
gnome-shell 40.
So far corner-rounding was only possible for StWidgets because the
rounded clipping was done using cairo drawing. We now need rounded
clipping for ClutterActors too because backgrounds are drawn using
ClutterActors (or more specifically a ClutterContent). To implement
that, first a ClutterOffscreenEffect subclass together with a fragment
shader from GSK (see gskSetOutputColor() [1] in the GSK GL renderer
code) was investigated, and while that was generic and worked quite
well, it was extremely slow for the case of drawing wallpapers because
of all the FBOs that had to be allocated.
This is the new, more performant approach: Use the same fragment shader,
but perform the rounded clipping right in MetaBackgroundContent while
we're painting the wallpaper. This has almost no performance impact,
with the downside of not being a generic solution.
To allow for rounded clipping not only at the edges of the wallpaper,
but using any given bounding rectangle, the API exposes not only the
radius, but also a bounding rect.
[1] https://gitlab.gnome.org/GNOME/gtk/-/blob/master/gsk/resources/glsl/preamble.fs.glsl
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1717>
Currently, the documentation for NotifyPointerAxis() just mentions that
a smooth scroll event is emitted.
However, this is not entirely correct. For each NotifyPointerAxis(),
mutter emits an emulated discrete scrolling event based on the
submitted accumulated smooth scrolling deltas.
Additionally, it doesn't mention how the motion deltas need to be
interpreted.
So, document the NotifyPointerAxis() notification better by mentioning
the emulation of discrete scroll events, how these discrete scroll
events are calculated and how the motion deltas need to be interpreted.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1727>
When a remote desktop user emits a virtual smooth scrolling event, a
smooth scroll event, that is not emulated, is emitted and on occasion
a discrete scroll event, that is emulated, is emitted.
As base for the discrete scrolling event, the smooth scrolling steps
are accumulated.
When the accumulated smooth scrolling steps surpass the
DISCRETE_SCROLL_STEP, the discrete scrolling event is emitted.
Currently, mutter uses for DISCRETE_SCROLL_STEP the value 10, which is
a terrible value to work with, especially for high resolution mouse
wheels.
When a triple resolution mouse wheel is used, each scrolling step will
have the value 3 1/3.
Three of such events won't however surpass the DISCRETE_SCROLL_STEP.
To fix this situation, add DBL_EPSILON to the calculation step, when
checking for the discrete scroll event to ensure that 3 smooth scroll
events, with each having the value 3 1/3, emit a discrete scrolling
event.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1727>
MetaVirtualInputDeviceX11 currently doesn't handle smooth scroll events
at all.
So, if a user of the remote desktop API uses smooth scroll events, then
only the wayland backend handles these events.
The user of the remote desktop API however, might not know which
backend is being used and actually the user should not even have to
care about it.
Actual smooth events cannot be emulated in the X11 events.
What can be done however is accumulating smooth events and then when
the accumulated steps surpass the DISCRETE_SCROLL_STEP value, emit a
discrete scroll event.
So, do exactly that, to make smooth scroll events work when the remote
desktop API is used with the x11 backend.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1727>
Given X11 nature, the pointer "leaves" the stage anytime it wanders into
a client window, or any other areas that are not deemed part of the
stage input region.
Yet we want to stay correct in those situations, e.g. have the clutter
side reasonably in sync, picking and highlighting to work properly, etc.
In order to achieve that, emulate motion events on XI_RawMotion. These
are as much throttled as our pointer tracking for a11y, in order to avoid
too many XIQueryPointer sync calls. This emulation only kicks in anytime
that X11 notifies us that we are not "on" the stage.
This replaces some sync_pointer() calls in GNOME Shell code that are
there just to compensate for this trait of X11, e.g. in the message tray
code.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1659>
Ensure we issue a motion event for the current pointer position,
as there might be situations where compositor modals get X grabs
from other clients stacked on top, or missed events in between
otherwise.
Ensure the Clutter state is still up-to-date afterwards here. This
replaces some sync_pointer() calls done in GNOME Shell code, always
done after modality changes.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1659>
Do these Wayland operations (that apply on both native and nested backends)
in the MetaCompositorServer subclass. We want to add more backend specific
behavior here in the future.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1659>
In the case that DnD is performed and succeeds, we want to release
the grab early, and let the transfer IPC happen in the back. For
that to happen without a hitch, drag source and offer must be left
related to each other after undoing the grab, even though the default
ungrabbing code does that automatically (indirectly, by unsetting the
drag focus).
In these cases, we used to manually unset the current source, so
this decoupling was skipped. Notably, one missed case is X11 DnD,
so we might end up with the situation there that DnD did succeed,
transfer is ongoing, but the source and offer are already decoupled,
this confused the machinery and missed the finishing XdndFinished
to be emitted to the X11 drag source.
The prior commits prepared for this source/offer decoupling being
a manual operation, this commit avoids doing this automatically
when ungrabbing.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1720>
This object is just being detached, with no code unref'ing it. Do
this whenever the XDnD selection goes unowned, usually a good
indication that the drag source no longer is one.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1720>
g_set_error_literal() asserts that the provided message is not NULL.
If it is NULL, the function is entirely no-op.
This resulted in a NULL dereference of the GError, which remained
NULL in this case, when trying to print a warning in
clutter_stage_cogl_redraw_view().
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1715>
PipeWire recently introduced busy buffers, which actually fixes the last remaining
issue that blocked us from downgrading these cogl_framebuffer_finish() calls into
cogl_framebuffer_flush() ones.
Switch to cogl_framebuffer_flush() in all three stream sources.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1701>
When a transfer request is done to the MetaSelectionSourceRemote source,
it's translated to a SelectionTransfer signal, which the remote desktop
server is supposed to respond to with SelectionWrite.
A timeout (set to 15 seconds) is added to handle too long timeouts,
which cancels the transfer request.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
Nothing is hooked up, it only does basic sanity checking i.e. whether
the clipboard was enabled when interacting with it. No actual clipboard
integration is hooked up yet.
This also syncs org.gnome.Mutter.RemoteDesktop.xml from
gnome-remote-desktop.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1552>
The original implementation of ::touch-mode tested for keyboard
presence to know whether the OSK and other touch-only features were
enabled.
However that didn't pan out, every webcam, card reader and kitchen
sink like to live a second life as EV_KEY devices. This made the
detection of actual external keyboards a much harder task than it
sounds, and was thus removed in commit f8e2234ce5.
Try a different approach here, and test for pointer devices, it
doesn't matter if internal or external devices, the rationales:
- It is significantly easier to get this right, there's virtually
no devices with abs/rel axes that don't try to be a real input
device of some sorts.
- It's not as good as testing for keyboard presence, but it's the
next best thing. These usually come in pairs, except in weird
setups.
- It is better than not having anything for a number of situations:
- Non-convertible laptops with a touchscreen will get touch-mode
disabled due to touchpad presence (plus keyboard). There's
been complains about OSK triggering with those.
- Same for desktop machines with USB touchscreens, the mouse
(and presumably keyboard) attached would make touch-mode
get in the middle.
- Convertible laptops with a broken tablet-mode switch get a
chance to work on tablet modes that do disable input devices
(e.g. detachable keyboards, or via firmware)
- Kiosk machines, tablets, and other devices that have a
touchscreen but will not regularly have a mouse/keyboard
will get the touch-mode enabled.
All in all, this seems to cover more situations the way we expect it,
there's only one situation that the OSK would show where it might
not be desirable, and one that might not show when it better should:
- Tablets and kiosk machines that get one keyboard plugged, but not a
mouse, will still show the OSK, despite being able to type right
away.
- Convertible laptops with broken/unreliable tablet-mode switch (e.g.
ignored by the kernel) rely entirely on the device/firmware
characteristics to work. If after folding into tablet mode the
touchpad remains active, touch-mode will not turn on.
Fixing the tablet-mode switch on these devices should be preferred,
as that'll also make libinput magically disable the touchpad.
The latter can be worked around with the a11y toggle. The former is
merely inconvenient, and nothing prevents the user from plugging a mouse
in addition.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1710>
Technically this is still wrong if the source actor or dnd actor are
transformed in other ways. However geometry scale is the by far most
common case and we currently lack convenience API in Clutter to
easily compute the right values.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1683>
When recording the screen and real time encoding it using a gstreamer
pipeline, that pipeline can stall when the encoder is too slow. Log a
debug message using the new SCREEN_CAST debug topic in that case so we
know when framedrops are happening.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1709>
Since commit c255031b6d, we allow some modifier+scroll events to
pass through to Clutter to enable gnome-shell to handle them. That
action shouldn't trigger a modifier-only action at the same time, so
reset the corresponding tracking just like we do for modifier+click.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1695>
Since commit c255031b6d we pass scroll-events through to
the compositor if the window_grab_modifiers are pressed;
in order to allow gnome-shell to check for those events,
expose the struct member as a MetaDisplay property.
Also take the opportunity to pick a more generic name, now
that the modifier is no longer used exclusively for mouse
clicks (unless we maintain the notion of scroll events as
button 4 and 5 "clicks").
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1695>
The other end of the PipeWire stream can set the buffer data type to a
bitmask of supported buffer types. We should respect this, and not
attempt to allocate a DMA buffer if it isn't asked for.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1697>
Instead of getters, pass the width, height and stride around when
relevant. This also removes the redudant "stream_size" and
"stream_height" variables from the src struct, as they are already part
of the video format.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1697>
Mutter freezes Xwayland commits when resizing windows, and thaw them in
the window actors' after_paint() for X11.
Yet, after_paint() could be never called, as when a new window is mapped
while the overview is active in gnome-shell.
As a result, the content of the X11 window will remain invisible to the
overview.
Add a new window actor API to tell whether commits can be frozen. For
Wayland window actors, this always return FALSE, whereas for X11 window
actors, it checks whether the Clutter actor is mapped.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1678>
When (un)maximizing, (un)fullscreening, the move/resize action is
flagged with 'ACTION_MOVE' and 'ACTION_RESIZE' , while e.g.
'appears-focus' does not.
When a client misbehaved and didn't immediately reply to a configure
request with a commit with the corresponding ack_configure, the
following commit would trigger a oddly timed move, making the window
appear to move back to a previous position.
Avoid this issue by only carrying over the target window position if the
configuration actually contained a new position.
We cannot only rely on the flags however, as e.g. a new position should
be respected during interactive resize, even though only 'ACTION_RESIZE'
is passed in such scenarios.
Do the same for the size, except if the window state dictates that the
size is fixed to a certain size, e.g. being fullscreen or maximized.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1445>
Mutter needs to fetch the X11 Window ID from the onscreen and did that
by using an X11 specific API on the CoglOnscreen, where the X11 type was
"expanded" (Window -> uint32_t). Change this by introducing an interface
called CoglX11Onscreen, implemented by both the Xlib and GLX onscreen
implementations, that keeps the right type (Window), while avoiding X11
specific API for CoglOnscreen.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1514>
Instead of calling "init_onscreen()" on two different separate vtables
from the allocate() funtion, just have the CoglOnscreen sub types
themself implement allocate() and initialize in there.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1514>
Thins means that e.g. MetaOnscreenNative now inherits CoglOnscreenEgl,
which inherits CoglOnscreen which inherits CoglFramebuffer, all being
the same GObject instance.
This makes it necessary to the one creating the onscreen to know what it
wants to create. For the X11 backend, the type of renderer (Xlib EGL or
GLX) determines the type, and for the native backend, it's currently
always MetaOnscreenNative.
The "winsys" vfunc entries related to onscreens hasn't been moved yet,
that will come later.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1514>
To get meta-renderer-native.c down to a bit more managable size, and to
isolate "onscreen" functionality from other (at least partly), move out
the things related to CoglOnscreen to meta-onscreen-native.[ch].
A couple of structs are moved to a new shared header file, as
abstracting those types (e.g. (primary, secondary) render devices) will
be dealt with later.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1514>
The mutter naming convention for types and their instance variables is:
Type name:
[Namespace][BaseName][SubType]
Instance name:
[base_name]_[sub_type]
This means that e.g. CoglOnscreenGLX is renamed CoglOnscreenGlx, and
glx_onscreen is renamed onscreen_glx. This is in preparation for
GObjectification.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1514>
Makes sure that monitor specs which may be read from EDID data do not
contain characters that are invalid in XML. Makes it possible to restore
monitor configs of monitor models with characters such as '&' in them.
To make this change not break any tests, the sample monitor configs need
to be adjusted as well. Apostrophes don't strictly have to be escaped in
XML text elements. However, we now do escape the elements in
`<monitorspec>` specifically.
Closes: <https://gitlab.gnome.org/GNOME/mutter/-/issues/1011>
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1685>
Previously the wl_resource and MetaWaylandGtkSurface corresponding to
any client gtk_surface have been kept around until the exit of the
client due to the client side destroy method not signaling the
destruction to the server. Ideally the protocol would have specified a
destroy request marked as destructor to handle this automatically,
however this is no longer possible due to the destroy method being
implicitly generated in the absence of an explicit request in the
protocol. Adding a destroy request marked as destructor now would
generate a new destroy method that unconditionally would send the
request to the server, which would break clients running on servers not
supporting that request.
So instead of modifying the destroy request add a new "release"
destructor, that indicates to the server that it can release the
resource. This can be optionally be used by clients depending on the
server protocol version.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1307>
The MetaWaylandSurface corresponding to a MetaWaylandGtkSurface can be
destroyed before the MetaWaylandGtkSurface is destroyed. In its destroy
function MetaWaylandSurface however was unsetting the destructor of the
correspnding resource along with the gtk_surface1 interface
implementation. This was done to prevent further gtk_surface1 requests
on a NULLed MetaWaylandSurface, if it has been destroyed before the
MetaWaylandGtkSurface.
It would be enough to just unset the resource implementation, while
keeping the destructor to fix this leak. However the following commit
will rely on the implementation being available after the
MetaWaylandSurface has been destroyed. So instead introduce NULL checks
for all functions that can be called on the gtk_surface1 interface and
do not unset the implementation.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1307>
If the monitor configuration changed, even though the streamed monitor
didn't change, we'd still fail to continue streaming, as we failed to
update the stage watchers, meaning we wouldn't be notified about when
the stage views were painted.
Fix this by reattaching the stage watches, i.e. update the painted
signalling listeners to listen to the right views, when monitor changes
happens.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1691>
Make the API used more shared and better named.
meta_monitor_manager_on_hotplug() was renamed
meta_monitor_manager_reconfigure(), and meta_monitor_manager_reload()
was introduced to combine reading the current state and reconfiguring.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1689>
It was named "backend_native" and "backend" which is easily confused with
MetaBackendNative and MetaBackend which tends to have those names.
Prepare for introducing the usage of a MetaBackendNative and MetaBackend
pointers here by cleaning up the naming.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1689>
Fullscreen X11 windows that attempt to change the resolution on Wayland
use a surface viewport to achieve this without affecting the resolution
of the display. This however also means that pointer events will be
delivered in the display coordinates while the code handling the window
frame is not aware of any such viewport scaling. So a right click
outside of the area corresponding to the new resolution will not be
considered to be on the client area. And since the only area that is
ignored when determining whether to perform the right click action, such
as opening the context menu, is the client area, this will result in the
action being performed, despite happening on the (scaled) client area.
While it would be possible to scale the event coordinates so that
get_control() correctly determines the frame element the cursor is on,
viewport scaling only affects fullscreen windows. Since fullscreen
windows have no frame, we can always assume that if the window gets
delivered an event for a fullscreen window, it is on the client area
without doing any additional calculations.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1592
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1661>
We remove pending pings when unmanaging a window, but currently
don't prevent new pings to be scheduled after that.
The previous commit fixed a code path where this did indeed happen,
but as the result of gnome-shell trying to attach a Clutter actor
to a non-existent window actor is pretty bad, also guard can_ping()
against being called for an unmanaging window.
https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2467
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1676>
This seems to have been the default in the past, but was (accidentally?) modified
by 8adab0275.
For GNOME 40, we'll be returning to our root with horizontal workspaces, so instead
of overriding it in GNOME Shell side, change the default back to what it once was.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1684>
We'll have two persistent client connections alive for the whole test,
one X11 client, and one Wayland client. So in order to be able to set up
the async waiter, do so after setting up the X11 client, as after that
we know we'll have a MetaX11Display ready to use.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1681>
One for the public channel, and one for the private maintainance
channel. Use the public one for test clients, otherwise tests become
flaky, and the private one for MetaX11Display.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1681>
This adds a MetaKmsImplDevice backend using atomic drmMode* API in constrast to
non-atomic legacy drmMode* API used in MetaKmsImplDeviceSimple.
This has various behavioral differences worth noting, compared to the
simple backend:
* We can only commit once per CRTC per page flip.
This means that we can only update the cursor plane once. If a primary
plane composition missed a dead line, we cannot commit only a cursor
update that would be presented earlier.
* Partial success is not possible with the atomic backend.
Cursor planes may fail with the simple backend. This is not the case
with the atomic backend. This will instead later be handled using API
specific to the atomic backend, that will effectively translate into
TEST_ONLY commits.
For testing and debugging purposes, the environment variable
MUTTER_DEBUG_ENABLE_ATOMIC_KMS can be set to either 1 or 0 to
force-enable or force-disable atomic mode setting. Setting it to some
other value will cause mutter to abort().
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/548
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1488>
