Sway 1.5-RC1 Wayland Compositor Brings VRR / Adaptive-Sync, New Protocol Support

Do they really need anything to agree about?
Wayland display server stores a number of buffers, one for each surface, and at some moment it composes a screen buffer from them and send it to the video driver. Also there are clients which may send to display server commands to replace a buffer of this surface. Without VRR support DS may wait for a vsync, then check if there were changes and compose a new screenbuffer.
To implement VRR support DS should just start a composition right after an application have updated it's surface. But, if there are more than one surfaces, this may lead to too frequent updates. So, compositor should decide which surfaces updates it should respect and which may wait until next occasion. This may be done by some protocol extension... But there will be many stupid programmers whose will activate this just to make animations smoother. So, perhaps it is better to use some simple heuristic, like attach VRR composition to a focused window or activate it for fullscreen apps only.

That makes perfect sense for composition of multiple windows. But, don't games need some more assistance with freesync, than just (not) waiting for vsync?

[Khrundel]

There wasn't one way to do it, so either they all agree how to do it in consistent manner, or it will be over all the place in each implementation.

Do they really need anything to agree about?
Wayland display server stores a number of buffers, one for each surface, and at some moment it composes a screen buffer from them and send it to the video driver. Also there are clients which may send to display server commands to replace a buffer of this surface. Without VRR support DS may wait for a vsync, then check if there were changes and compose a new screenbuffer.
To implement VRR support DS should just start a composition right after an application have updated it's surface. But, if there are more than one surfaces, this may lead to too frequent updates. So, compositor should decide which surfaces updates it should respect and which may wait until next occasion. This may be done by some protocol extension... But there will be many stupid programmers whose will activate this just to make animations smoother. So, perhaps it is better to use some simple heuristic, like attach VRR composition to a focused window or activate it for fullscreen apps only.

[lucrus]

Do someone have the instructions/hints to make work sway with nvidia? I'd like to give it a shot.

From https://github.com/swaywm/sway/issues/490, last comment:

There are overwhelming technical and non-technical arguments as to why we are not going to support it [nvidia]. Face it, we are never going to support them. There is absolutely no point bringing it up; you are not going to change our minds.

The only possible hint is to use the nouveau driver, assuming it supports your nvidia card enough to run sway.

[Tsih]

Does this VRR work in multi monitor environments? in particular when one monitor doesn't do GSYNC. That was the BIG issue with X11 for me, couldn't use GSYNC when second monitor was connected even if the application wasn't running fullscreen on that second monitor, it just disables gsync all together.

The other issue was this VRR/Gsync function flickered on my freesync1 monitor whereas that flicker did not exist under windows..

VRR does work with multiple monitors on AMD, I've got 4k 60Hz and 1440p 144Hz monitors with VRR enabled. However I don't think nouveau supports G-sync and Sway doesn't work with the proprietary driver.

[Zeioth]

Do someone have the instructions/hints to make work sway with nvidia? I'd like to give it a shot.

[andrei_me]

As Sway is window manager instead of a desktop environment, those programs that I'm used to use from DE work on it?

Or other programs that might used QT/GTK like firefox, sublime text, vscode, eclipse?

[kpedersen]

There wasn't one way to do it, so either they all agree how to do it in consistent manner, or it will be over all the place in each implementation.

Because of the sheer amount of engineering required to develop a compositor for Wayland, there will never be that many. It is not like X11 where anyone can commit to writing a window manager (thus driving innovation).

Because of this lack of variety, "being all over the place" will really just mean two or three different ways.

[treba]

Nice to see viewport support - that should help future performance work for firefox, see https://bugzilla.mozilla.org/show_bug.cgi?id=1617498

[polarathene]

Does this VRR work in multi monitor environments? in particular when one monitor doesn't do GSYNC. That was the BIG issue with X11 for me, couldn't use GSYNC when second monitor was connected even if the application wasn't running fullscreen on that second monitor, it just disables gsync all together.

AFAIK, that's because multi-display on X11 was one big display / buffer and it just crops from that. With Wayland that shouldn't be an issue anymore, but I don't know for sure.

[cRaZy-bisCuiT]

That sounds good!

Do you know what is the current state of wlroots regarding vulkan support? Can I natively run Vulkan fullscreen applications on Wayland nowadays? Like e.g. SDL Games with Vulkan support like Dota 2.