When starting up, the compositor might call wlr_output_set_mode()
with a mode which is already the current one. wlroots will detect
this and make the wlr_output_set_mode() call a no-op. During the
next wlr_output_commit() call, wlroots will perform an atomic
commit without the ALLOW_MODESET flag.
This is an issue, because some drivers need ALLOW_MODESET even if
the mode is the same. For instance, if the FB stride or modifier
changed, some drivers require a modeset.
Add a new flag "allow_artifacts" which is set when the compositor
calls mode-setting functions. Use this flag to figure out whether
we want to perform atomic commits with ALLOW_MODESET.
(The name "allow_artifacts" is picked because ALLOW_MODESET is a
misnomer, see [1].)
[1]: https://patchwork.freedesktop.org/patch/505107/
Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3499
In wlr_output_attach_render(), stop setting
wlr_output.pending.buffer. This removes one footgun: using the
wlr_buffer at that stage is invalid, because rendering operations
haven't been flushed to the GPU yet. We need to wait until
output_clear_back_buffer() for the wlr_buffer to be used safely.
Instead, set wlr_output.pending.buffer in wlr_output_test() and
wlr_output_commit().
Additionally, move the output_clear_back_buffer() from
wlr_output_commit_state() to wlr_output_commit(). This reduces the
number of calls in the failure path.
We can just use pending.buffer instead. It's completely fine to
call wlr_swapchain_set_buffer_submitted() with a buffer which
doesn't come from the swapchain, in which case it's a no-op.
This is documented to reset the gamma LUT, but we don't handle this
properly.
While at it, make sure we leave wlr_output.pending in a good state
on allocation failure.
If the first test in output_ensure_buffer() fails with modifiers we
replace the swapchain with a modifierless swapchain and try again.
However if that fails as well the output is currently stuck without
modifiers until the next modeset.
To fix this, destroy the modifierless swapchain if the test using it
fails. The next output_attach_back_buffer() call will create a swapchain
that allows modifiers when needed.
When using direct scanout back_buffer is NULL. We'd emit a commit
event with WLR_OUTPUT_STATE_BUFFER set but with a NULL buffer field,
which is non-sensical.
The previous wlr_output_cursor_set_image() allows setting a NULL buffer for the
cursor to hide it. This functionality was used by sway to hide the cursor,
restore the original semantics by allowing NULL buffers again by avoiding the
wlr_buffer allocation in case we have NULL pixels and handing a NULL wlr_buffer
to wlr_output_cursor_set_buffer().
Before calling wlr_output_impl.{test,commit}, perform a cheap
comparison between the current and candidate state. Unset any
fields which didn't change.
This refactors output_ensure_buffer() to not mutate the state passed,
making the previous subtle behavior much more explicit.
Fixes: d483dd2f ("output: add wlr_output_commit_state")
Closes: #3442
This allows the make/model/serial to be NULL when unset, and allows
them to be longer than the hardcoded array length.
This is a breaking change: compositors need to handle the new NULL
case, and we stop setting make/model to useless "headless" or
"wayland" strings.
When calling wlr_output_test an empty buffer might be created. This implicitly
changes the pending state of the output. Ensure that such a change is only
temporarily and clear such an empty buffer before returning the test result.
wlroots picks names for all outputs, but it might be desirable for
compositor to override it.
For instance, Sway will use a headless output as a fallback in
case no outputs are connected. Sway wants to clearly label the
fallback output as such and label "real" headless outputs starting
from HEADLESS-1.
This allows output commit listeners to access the newly committed
buffer. Currently wlr_output.front_buffer is used but it'll get
removed in the next commit.
DRM formats with an empty modifier list are invalid. Instead of
emptying the list, reduce it to { INVALID }.
Add a check to make sure the renderer and backend support implicit
modifiers, so that we don't fallback on e.g. Vulkan.
Closes: https://github.com/swaywm/sway/issues/6692
This allows compositors to get primary formats without manually
calling wlr_output_impl.get_primary_formats.
For example, the Sway patch for linux-dmabuf feedback [1] needs
this.
[1]: https://github.com/swaywm/sway/pull/6313
Sometimes we were calling wlr_output_impl.set_cursor with a NULL
buffer, but we weren't clearing wlr_output.cursor_front_buffer.
Avoid leaving a dangling buffer behind.
Introduce a helper function output_set_hardware_cursor which calls
wlr_output_impl.set_cursor and keeps cursor_front_buffer in sync.
All graphics drivers supporting cursor planes support ARGB8888,
the default cursor format, so this fallback is almost certainly
unused.
Essentially all cursor themes use alpha transparency to make it
clearer where relative to the screen content the cursor hotspot is.
It is better to fall back to a slightly slower software cursor than
it is to fall back to the opaque square that is a hardware cursor
without an alpha channel.
This change introduces new double buffered state to the wlr_output,
corresponding to the buffer format to render to.
The format being rendered to does not control the bit depth of colors
being sent to the display; it does generally determine the format with
which screenshot data is provided. The DRM backend _may_ sent higher
bit depths if the render format depth is increased, but hardware and
other limitations may apply.
Most (and possibly all) compositors using wlroots only ever render
fully opaque content. To provide better performance, this change
switches the default format used by wlr_output buffers from
ARGB8888 to the opaque XRGB8888.
Compositors like mutter, kwin, and weston already default to
XRGB8888, so this change is unlikely to expose any new bugs in
underlying drivers and hardware.
This does not affect the hardware cursor's buffer format, which is
still ARGB8888 by default.
As part of this change, the X11 backend (which does not support
changing format at runtime) now picks a true color, 24 bit depth
visual (i.e. XRGB8888) instead of a 32 bit depth (ARGB8888) one.
This makes it possible for the two functions using output_pick_format
(output_pick_cursor_format and output_create_swapchain) to select
different buffer formats.
The backend and renderer don't directly interact together, so there's
no point in checking that their buffer caps intersect. What we want to
check is that:
- The backend and allocator buffer caps are compatible, because the
backend consumes buffers to display them.
- The renderer and allocator buffer caps are compatible, because the
renderer imports buffers to sample them or render to them.
For instance, when running with the DRM backend and the Pixman renderer,
the (backend & renderer) check will fail because backend = DMABUF and
renderer = DATA_PTR.
