Bug 430829

Summary: Pen lag / latency when on ChromeOS (Google Pixel Slate i5)
Product: [Applications] krita Reporter: Luc <lafreniere.luc>
Component: Tablets (tablet issues are only very rarely bugs in Krita!)Assignee: sh_zam <shzam>
Status: ASSIGNED ---    
Severity: normal CC: griffinvalley, halla
Priority: NOR    
Version First Reported In: 4.4.2-beta1   
Target Milestone: ---   
Platform: Android   
OS: ChromeOS   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Luc 2020-12-26 14:21:39 UTC 
Although the new Krita for Android on a Chromebook is very usable, there is significant lag when using an active stylus as compared to the best apps available.

For some reason, MANY art based programs have lag issues when it comes to using the stylus. BUT there are two examples of software that has practically minimal lag.

https://canvas.apps.chrome/ is a web based PWA made by Google. When drawing in this program, the lag is incredibly small. It feels practically non existent.

https://www.squidnotes.com/ this Android app is not an art based program but for note taking. Regardless, it has achieved similar latency as the Canvas PWA by Google.

Both of those examples are the best with pen lag. My wife, a fine arts major, art teacher and avid home artist loves Krita now that it's available on ChromeOS. But watching her draw on Krita vs. Canvas is night and day. She loves all the extra functionality of Krita but sadly the pen lag is a pretty big issue. Canvas on the other hand has no pen lag but severely lacks in features. Squid is just a note taking app, but it's an example of an Android app achieve no lag.

So the question becomes, is it possible for Krita to have this level of lag? Squid proves that Android apps can achieve this... Canvas, although a PWA, also proves this. It would be awesome if Krita could have reduced pen lag matching those.

More than happy to do any testing required.

Merci.
Comment 1 Luc 2021-01-21 13:56:12 UTC 
Any chance this will get any attention? Thanks.
Comment 2 Halla Rempt 2021-01-21 14:50:33 UTC 
Google has created a special low-level, low-latency stylus api that went in beta last year. Unfortunately, it's directly tied to the display system as well, and we cannot use it.
Comment 3 Luc 2021-01-21 14:51:50 UTC 
(In reply to Halla Rempt from comment #2)
> Google has created a special low-level, low-latency stylus api that went in
> beta last year. Unfortunately, it's directly tied to the display system as
> well, and we cannot use it.

Fascinating... and Squid got access to it somehow? That's frustrating if it's capable but not available...
Comment 4 Halla Rempt 2021-01-21 15:10:03 UTC 
We were offered access as well, but it doesn't fit in with Krita's current architecture.
Comment 5 Luc 2021-01-21 15:12:42 UTC 
(In reply to Halla Rempt from comment #4)
> We were offered access as well, but it doesn't fit in with Krita's current
> architecture.

OK, thanks. Something to hopefully consider down the line? Chromebooks are pretty popular and from what I've seen in the tech world, getting more popular, especially in education. Krita is a wonderful program, my wife is very impressed with it after trying everything available. But the latency is sadly one of the only significant problems we've had with Krita It's obviously a huge and obvious "issue". Still workable, but when you see "what could have been"... 

Well thanks for responding and clarifying. I won't get my hopes up on this one. Too bad...