Bug 375905 - [HUION] Incorrect pressure information with Huion WH1409
Summary: [HUION] Incorrect pressure information with Huion WH1409
Status: RESOLVED UPSTREAM
Alias: None
Product: krita
Classification: Applications
Component: Tablets (tablet issues are only very rarely bugs in Krita!) (show other bugs)
Version: 3.1.2
Platform: macOS (DMG) macOS
: NOR normal
Target Milestone: ---
Assignee: Krita Bugs
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-02-02 18:04 UTC by Ryokun
Modified: 2017-05-15 10:41 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Huion WH1409 (306.69 KB, image/jpeg)
2017-02-02 18:04 UTC, Ryokun
Details
terminal log (1.83 MB, text/plain)
2017-05-12 11:26 UTC, Ryokun
Details

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Description Ryokun 2017-02-02 18:04:45 UTC
Created attachment 103778 [details]
Huion WH1409

The strokes are not made at the right pressure with a HUION WH1409 (see the attached picture because it’s really hard to describe with words).

How to reproduce:
Select brush fill_circle (in my test: presets default, just changed the size from 50 to 100px. Opacity is 100%).
make more or less vertical and horizontal lines by pressing slightly on the pen: the pressure information seems to jump from high values to low values.

What's expected:
a line with a diameter varying smoothly.

Comments:
This one is really strange because it happens with only 1 of my 3 computers (the Retina one, unfortunately my main computer). The tablet driver is exactly the same on the 3 computers, as well as the Krita version. So if someone has an idea...

More informations:
- The pressure curve on the brush is the one by default.
- The problem occurs whatever brush you choose (unless the size variation is deactivated)
- Tested on a MacBook Air 2013 with Mac OS 10.12, the same graphics tablet with the same version of Krita (3.1.2) and the same version of the tablet driver -> all works perfectly.
- Same thing with an iMac 2009 (Mac OS 10.11, Krita has the same version number as well as for the tablet driver): all works perfectly.
- The tablet works perfectly on the same computer with Photoshop CC 2017
- The tablet works perfectly on the same computer with the application to test the tablet provided by Huion.
Comment 1 Halla Rempt 2017-05-12 08:13:31 UTC
Hm... I'm wondering about that. On OSX, the tablet api is built-in into the OS, so the driver provides the data to the os, the os to Qt, Qt to Krita. Could you make a tablet log like I explained in the other bug of yours? I figure we're just sometimes getting really weird pressure info from the OS for some reason.
Comment 2 Ryokun 2017-05-12 11:26:57 UTC
Created attachment 105471 [details]
terminal log

Hi,

The bug is no more :)

I attached the same log as the bug 375908. I made it before updating my Huion tablet drivers. You can clearly see that the pressure informations are sent 2 times with totally different values (by example: lines 4773-4774: prs: 0.323232 and prs: 0.160784 for the same x-y coordinates).
On another computer, the same pressure informations where really near one another, so I updated my tablet drivers and now it works as it should ! (note that I already updated them before posting this bug, but it still didn't work then). Maybe the Huion driver had this behavior only on Retina displays ? I don't hnow....

I still think it worked in other applications because they manage event coalescing differently than Krita (in other words, they only interpret the highest pressure value).
But Krita is not wrong on this so don't change anything. Now that Huion corrected this problem, you can close this bug.
Many thanks.
Comment 3 Halla Rempt 2017-05-15 10:41:57 UTC
Thanks for the info!