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
If a new buffer is set for a buffer node, we must update the entire
node unconditionally if the buffer size changes, or the buffer is given
a buffer where it was previously NULL.
While we're here, let's avoid calling scene_node_update on just damage
updates. If the caller hasn't given us a damage region we just assume
the whole buffer.
If the area calculations for output overlap overflow a signed int, we
may not consider it to be a primary output. Turn this into an unsigned
type so this happens less frequently.
Additionally, it is possible the overflow would produce 0, we can handle
this by simply changing the comparison to more than or equal.
While we're here, let's assert that we always assign a primary output
if there are any intersecting outputs.
We were crashing in the error codepath [1] when
wlr_drm_create_lease() fails.
To fix this, delay the creation of the wlr_drm_lease_v1 until the
request is granted. Previously we were allocating that struct early
without populating the drm_lease field. However that means we ended
up with a half-constructed struct in the error codepath which is
annoying to handle.
[1]: https://github.com/swaywm/sway/issues/7204#issuecomment-1269797356
On first commit, require a new buffer if the compositor called a
mode-setting function, even if the mode won't change. This makes it
so the swapchain is created now.
Stop trying to check whether the backend supports buffer-less modesets
because that makes everything more complicated. For instance, the
DRM backend doesn't need a new buffer if the previous DRM master left
the output enabled.
Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3499
Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3502
Some compositors want to have full control over the buffers attached
to the output, and don't want to use the internal swapchain. Such
compositors include KWinFT (allocates its buffers on its own) and
gamescope (uses a headless output without any buffers).
Let's just make output_ensure_buffer() a no-op in that case.
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
Instead of using low-level wl_shm_buffer and wlr_dmabuf_v1_buffer
APIs, use the unified wlr_buffer APIs. That way it doesn't matter
what the exact wlr_buffer implementation is used, any which provides
the necessary capabilities (data_ptr or dmabuf) would work.
Simplifies the logic a bit, and will make the transition to wlr_shm
easier.
