Tearing/Vsync issues in Cinnamon/Clutter

Running nVidia hardware on multiple machines, and along with other nVidia users I have bad screen tearing in Cinnamon/Clutter unless the game has a VSYNC option which forces it on, then things work fine. For some reason VLC doesn't have tearing that I can notice, but Totem always has horrible tearing.

The solution being done by several users right now is to switch to the Compton compositor instead and forcing on VSYNC for everything through that, but can't we get an option to force it on for Cinnamon instead? For some reason the usual Cluttter options do NOT force on VSYNC. See the following threads on the Linux Mint forums and Reddit:

http://forums.linuxmint.com/viewtopic.php?f=59&t=171020
http://www.reddit.com/r/linux_gaming/comments/28skqt/psa_do_you_have_screen_tearing_issues_only_in/

Also found this suggestion to add a VSYNC option to Cinnamon options, but if that option doesn't work anyway then that won't fix the problem.

#1773

Using nVidia closed driver.

[mtwebster]

Is this something demonstrable with Intel graphics?

nVidia hardware so far as I said. No clue about Intel. Do you have Intel hardware? Do you see any screen tearing in games or movies in Totem? This has always been a problem for me on Mint.

If there is a setting that successfully can force vsync on in every app perhaps it should be made the default configuration setting for all nVidia hardware.

[pinumbernumber]

Intel here (4500MHD) and there is tearing everywhere out of the box. Adding some Clutter environment variable hacks gets rid of it but then everything is jerky and slow to respond (dragged windows lag behind the cursor).

What Clutter variable are you using out of curiosity? One or both of these?

CLUTTER_PAINT=disable-clipped-redraws:disable-culling
CLUTTER_VBLANK=True

[pinumbernumber]

Tried each of those as well as both, no dice. Note: GNOME and most other Xorg DEs also seem to do this. Weston doesn't.

But is that what you used to eliminate tearing?

As for things slowing down when you did apply whatever tearing fix you used, that might be due to some inefficiency in Clutter and/or the particular fix you used. If I were you I'd give Compton a try and see if you get no tearing + better performance than Clutter. Corvias has it posted here:

http://www.reddit.com/r/linux_gaming/comments/28skqt/psa_do_you_have_screen_tearing_issues_only_in/

[pinumbernumber]

Sorry, yes the CLUTTER_PAINT line fixes tearing by itself but it causes the other problems I described.

As for the other fix, it says to install Openbox. Is it possible to use Compton with Cinnamon?

I was curious about that myself as well, I saw it mentioned that there is no "--replace", so you cannot swap in Compton and swap out Clutter once running Cinnamon, but maybe there is a way to load up Cinnamon with Compton instead, not sure how to though.

It looks like trying out Compton is pretty easy though, just install the Openbox metapackage, Compton, make the config file and select Openbox in the login manager to log into. Curious to try it out myself now when I have some spare time to see if I get any performance differences in games.

[mtwebster]

So, here: linuxmint/muffin#86, we made detection of these types of programs better, to improve their performance (by not compositing them). People were beating down the doors saying we needed to do this if Cinnamon was to be a gaming platform. (I'm not exaggerating!)

So, now, we seem to have exposed this side effect of tearing (of course), which I can't reproduce yet, but I'm going to keep trying.

Ideally, we have the performance and the no-tearing, but aren't the two mutually exclusive to a degree? Honestly I'm not very familiar anymore with the different drivers and manufacturers out there. I'd welcome more input (and of course I'll continue to look for more info too).

Yeah it is indeed a strange issue. My understanding is X.org by default doesn't want to vsync, whereas Wayland by default does want to vsync, so Wayland apps don't have to implement code to force vsync on like they do with X apps.

There are a lot of movies and games in which tearing is particularly visible and I can easily see a line(s) across my monitor. There are several other games where it isn't though. It may depend on what monitor you have, too. That's why perhaps having a setting in Cinnamon to force on or off vsync might be the best solution, and then based upon certain hardware perhaps you could change what the default setting should be, or just not bother with that last part.

It's easiest to notice in situations where large blocks of graphics are moving, so movies are particularly noticeable.

Some Steam games I've noticed it in extra easily (pan around the screen):
Snapshot
XCOM (until they implemented vsync support, it was especially noticeable in movie sequences)
Defense Zone 1 and 2
World of Goo
Probably several others I can't think of at the moment. Many games are OK due to having vsync options in-game, especially many of the "higher-end" games like Painkiller and Civilization.

I couldn't reproduce it on any open source games yet.

Totem/Movie Player is very easy to reproduce though. Can play any movie, especially high-res movies, I get a very solid tearing line at 1/3rd of the way down my screen. However, VLC does not have this issue so that is what I use on my HTPC with Mint 17 and nVidia. Using some other type of output apparently.

What I haven't done yet is compare framerate performance between Compton and Cinnamon and other WMs. If Compton fixes screen tearing and gives a better framerate, maybe Cinnamon should switch to it instead of Mutter/Muffin. XD

I'm definitely willing to do tests and troubleshooting in my spare time if there are any helpful tests that I can do or things I can try. ^n.n^

[mtwebster]

The thing that gets me (unless I'm misreading about Compton) is an easy fix would just be to force redirection (compositing) on these windows, or simply provide a switch (like in an applet) to allow you to disable unredirect detection - nothing to do with vsync at all.

Discussing with someone who knows a bit more about video cards, and reading a bit myself, it seems like they all have their own way to force vsync on or off, and as you mentioned, some of the programs themselves do as well. So would it be satisfactory to simply avoid the issue and force compositing in these cases?

Right, unless there is a way to have Muffin adjust a program's settings to avoid screen tearing, it'd probably be best to have an option to force it on everywhere, just like you can do with Compton from what I understand from what Corvias has said here:
http://www.reddit.com/r/linux_gaming/comments/28skqt/psa_do_you_have_screen_tearing_issues_only_in/
with:
compton -b --backend glx --vsync opengl-swc

...since it looks like the "sync to vblank" option in the nVidia control panel is useless or helpless in fixing it. XD

I need to play with some Muffin settings and see if I can fix tearing through it. Do you know of any settings that might do so? If I remember correctly in Mint 16 I used some settings that fixed tearing, but Corvias tried "everything" he said and couldn't get it fixed without using Compton, but I still need to try myself.

Either way, once the right setting or solution is found, having an option in Effects or someplace better for that might be good. That'd be easy enough I could add it myself. XD

[AlbertJP]

Has any of you already tried Gnome Shell to see if the tearing (and other vsync issues) also happen there?

I've heard complaints of Gnome Shell having vsync issues, but have not tried it yet myself. I'll install a few DEs this weekend and try things out.