- 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
This is needed for compositors that want to reserve space for
XWayland panels. Such a feature can be useful in a "transitional"
setup, where only the X11 window manager and compositor is replaced
but other components of an X11 desktop environment are still used.
This change simply reads the X11 property; the compositor is free
to ignore it. Thus, compositors that don't want to support such a
"transitional" feature are not impacted.
v2: Update xwayland_surface_associate()
The invalid_destroy and invalid_unlock protocol errors aren't currently
sent by wlroots and instead left up to the compositor. However, we can
handle these as well without much additional complexity.
This also adds a missing wl_resource_destroy() call if the lock is inert
in lock_handle_unlock_and_destroy().
wlroots uses "// private state" comments to denote structure fields
which shouldn't be accessed by compositors, so let's drop
wlr_output_layout_output_state and inline its fields into
wlr_output_layout_output; this also simplifies layout output creation.
Query the formats at init time, then forget about the renderer.
This will allow wl_drm to be created with a list of formats instead
of a renderer, and will behave better after a GPU reset.
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
