This changes the semantics of wlr_output_state. Instead of having
fields with uninitialized memory when missing from the committed
bitflag, all fields are always initialized (and maybe NULL/empty),
just like we do in wlr_surface_state. This reduces the chances of
footguns when reading a field, and removes the need to check for
the committed bitfield everywhere.
A new wlr_output_state_init() function takes care of initializing
the Pixman region.
Add a src_box state field. Use the SRC_* KMS props in the DRM
backend, reject the layers in the Wayland backend (for now, we can
support it later via viewporter).
wlr_output is not well-suited to checking whether direct scan-out
is happening or not. Compositors may want to use their own external
swapchains, for instance.
Additionally, ab7eabac84 ("output: leverage
wlr_output_configure_primary_swapchain()") makes it so
output_basic_test() is called before the output swapchain is
initialized, resulting in false positives.
References: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3620
This allows callers to set a destination size different from the
buffer size to scale them.
The DRM backend supports this. The Wayland backend doesn't yet
(we'd need to wire up viewporter).
- Simplifies the backends
- Avoids having two ways to do the same thing: previously one could
disable a layer by either omitting it from wlr_output_state.layers,
or by passing a NULL buffer
- We can change our mind in the future: we can allow users to omit
some layers and define a meaning without breaking the API.
References: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/4017#note_1783997
We've had this struct for a while. It'd be useful for compositors
if they want to manage the swap chains themselves instead of being
forced to use wlr_output's. Some compositors might also want to use
a swapchain without an output.
This is based on previous work [1] [2].
This new API allows compositors to display buffers without needing to
perform rendering operations. This API can be implemented on Wayland
using subsurfaces and on DRM using KMS planes.
Compared to [1], this approach leverages wlr_addon_set to let backends
attach their own private state to layers, removes the pending
state (necessary for interop with wlr_output_commit_state()) and
enum wlr_output_layer_state_field.
[1]: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/1985
[2]: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/3447
The backend no longer changes the output state behind the
compositor's back. Instead, compositors can listen to the "commit"
event and check for WLR_OUTPUT_STATE_ENABLED/WLR_OUTPUT_STATE_MODE.
Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/2300
If a fixed mode matching the user requirements is available, use
that. This avoids generating the mode with GTF or CVT in the DRM
backend, and instead uses mode timings advertised by the output.
References: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3514
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.
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.
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
Alexander Orzechowski
Simon Ser
Kirill Primak
Alexander Orzechowski
Isaac Freund