Before of this patch, as explained in the usual
commented-wall-of-text-longer-than-the-actual-patch-itself™, due to the
multithreaded nature of the Wayland thread, it was possible to commit a
surface while the renderer was doing stuff, which was _very_ wrong.
Initially the consequences of such a sin weren't obvious but, now that
explicit synchronization is becoming more and more common, we can't
commit a buffer randomly without basically guaranteeing a nasty, nasty
crash (and we should have avoided commits altogether in the first place
to ensure atomic surface updates).
We now only trigger a commit _in the main thread_ when low processor usage
mode is on _and_ if we know that we won't be rendering anything as, due to
its intermittent nature, it makes "legacy" (pre xdg_wm_base v6) frame
callback based suspension quite annoying.
This avoids any assumption from the driver, which would otherwise select
a specific platform and potentially mess up everything, resulting
usually in a display server failure.
Mainly, this fixes auto UI scaling with _single-monitor_ fractional
setups (see the comment in `display_server_wayland.cpp` for more info).
This is the result of a bunch of current limitations, mainly the fact
that the UI scale is static (it's probed at startup) and the fact that
Wayland exposes fractional scales only at the window-level, by design.
The `screen_get_scale` special case should help in 99% of cases, while
the auto UI scale part will unfortunately only help with single-screen
situations, as multi-screen fractional scaling requires dynamic UI
scale changing.
Random-access access to `List` when iterating is `O(n^2)` (`O(n)` when
accessing a single element)
* Removed subscript operator, in favor of a more explicit `get`
* Added conversion from `Iterator` to `ConstIterator`
* Remade existing operations into other solutions when applicable
Previously we pretty much hardcoded most of the globals we requested,
causing compatibility issues with certain compositors like Weston, which
support only some pretty old versions or miss some more advanced
protocols.
To put fuel on the fire, we also errored out when certain protocols
weren't available, despite us being able to boot a game just fine (but
obviously with a degraded featureset).
The solution is to simply allow all the way from version 1 to the
current latest, adding some compatibility code (such as for older
`wl_output`s or newer `wl_pointer`s).
While we're at it, this commit also fixes a few typos and naming inconsistencies
I found.
Before, the cursor kept updating for no good reason really.
It's also a bit neater and it ever-so-slightly makes `WAYLAND_DEBUG`
logs easier to read, although they're still spammed by the window's
frame logic (which is needed).
This code was already partially there, although heavily incomplete and
nowadays commented out.
It got broken after the `WaylandThread` refactor and I didn't bother to
bring it over, preferring to `#if 0` it into oblivion for the time
being as I don't have a tablet/pen which support an eraser and tilt
reporting.
This commit brings it back and adds proper multi-tool support (needed
for eraser detection) thanks to winston-yallow, who could test this code
with their more capable tablet.
This is a pretty popular approach that took a while for me to wrap my
head around and which only recently got "official" support through an
update (xdg_shell version 6), so I think that this is all-in-all a
better option than the overkill 2000Hz ticking we have now :P
Basically, we wait for a frame event and, if either too much time passes
or we get the new `suspended` state, we consider the window as "hidden"
and stop drawing, ticking by the low usage rate.
This should work great for KDE and Mutter, which support the new state,
but not yet for sway, which is still stuck at a very old xdg_shell
version and thus falls back to the timeout approach.
Be aware that if we rely on timing out the engine will have to stall for
the whole timeout, which _could_ be problematic but doensn't seem like
it. Further testing is needed.
Special thanks go to the guys over at #wayland on OFTC, who very
patiently explained me this approach way too many times.
Using 2.2.7.dev115+g0eb441d6.
Had to add `cancelled` to the ignore list, as it's a Wayland signal which
we're handling in our code, so we don't want codespell to fix that "typo".
Also includes the typo fix from #87927.
Co-authored-by: Divyanshu Shekhar <61140213+divshekhar@users.noreply.github.com>
