Instead of ensuring the renderer and allocator are initialized in each
backend, do it in wlr_backend_autocreate. This allows compositors to
create backends without any renderer/allocator if they side-step
wlr_backend_autocreate.
Since the wlr_backend_get_renderer and backend_get_allocator end up
calling wlr_renderer_autocreate and wlr_allocator_autocreate, it sounds
like a good idea to centralize all of the opimionated bits in one place.
Custom backends and renderers need to implement
wlr_backend_impl.get_buffer_caps and
wlr_renderer_impl.get_render_buffer_caps. They can't if enum
wlr_buffer_cap isn't made public.
When picking a format, the backend needs to know whether the
buffers allocated by the allocator will be DMA-BUFs or shared
memory. So far, the backend used the renderer's supported
buffer types to guess this information.
This is pretty fragile: renderers in general don't care about the
SHM cap (they only care about the DATA_PTR one). Additionally,
nothing stops a renderer from supporting both DMA-BUFs and shared
memory, but this would break the backend's guess.
Instead, use wlr_allocator.buffer_caps. This is more reliable since
the buffers created with the allocator are guaranteed to have these
caps.
This new functions cleans up the common backend state. While this
currently only emits the destroy signal, this will also clean up
the renderer and allocator in upcoming patches.
Split render/display setups have two separate devices: one display-only
with a primary node, and one render-only with a render node. However
in these cases the EGL implementation and the Wayland compositor will
advertise the display device instead of the render device [1]. The EGL
implementation will magically open the render device when the display
device is passed in.
So just pass the display device as if it were a render device. Maybe in
the future Mesa will advertise the render device instead and we'll be
able to remove this workaround.
[1]: https://gitlab.freedesktop.org/mesa/mesa/-/issues/4178
It turns out wl_event_source_check is not enough to guarantee that the
remote wl_display will be flushed after we queue requests. We need to
explicitly flush, just like we do in our X11 code.
References: https://gitlab.freedesktop.org/wayland/wayland/-/issues/187
This callback allowed compositors to customize the EGL config used by
the renderer. However with renderer v6 EGL configs aren't used anymore.
Instead, buffers are allocated via GBM and GL FBOs are rendered to. So
customizing the EGL config is a no-op.
The Wayland platform doesn't have visuals. By chance,
WL_SHM_FORMAT_ARGB8888 is zero, which means egl_get_config was ignoring
it and everything worked fine.
Previously, an error on the remote Wayland display would result in an
infinite loop priting:
2020-01-09 13:39:03 - [wayland] Source dispatch function returned negative value!
2020-01-09 13:39:03 - [wayland] This would previously accidentally suppress a follow-up dispatch
This happens when the remote compositor disconnects the client because
of a protocol error, for instance.
Handle wl_display_dispatch and wl_display_dispatch_pending returning -1
by terminating the local display and printing an error.
Expose the remote wl_display, wl_surface and wl_seat used by the Wayland
backend.
This allows compositors to customize the Wayland backend and to have
more freedom. For instance a compositor might want to handle clipboard
and drag-and-drop from the remote Wayland compositor. Another compositor
might want to setup pointer constraints.
We just send relative motion events alongside absolute motion events.
Compositors can figure out how absolute and relative events are related
(e.g. whether they have been triggered by the same logical event) with
the frame event.
This allows wlroots based compositors to properly use graphic tablets
with the wayland backend.
This should be a decent quality of life improvement when working on
tablet related features.
