Hi!

Pressure support is provided by the Qt library Krita uses -- we don't have code for that ourselves. There is already a patch in Qt's bug tracker for adding support non-Wacom tablets, but it appears that nobody inside the Qt development team has a non-Wacom tablet, nor do any of the Krita developers. I'm not sure how expensive a g-pen tablet is, but if you can get together with some others and donate one of those to the Krita team, we can test the patch and try to get it into Qt. You could also try to help us out by testing this patch and providing feedback to the Qt team, or maybe even helping out improving the patch if necessary.

This is the link to bug with the patch: https://bugreports.qt-project.org/browse/QTBUG-25329

Thanks for the reply.

I don't know people who use g-pen in my area view. So, i'm the only one donator. G-pen Tablet costs 100$(the cheapest one)-250$.

I can use only deb packages for testing. I'm not good in compiling.

Have you taken a look at the compilation script available in the forum? viewtopic.php?f=139&t=92880

hi guys.

Sorry for long reply. I bought G-Pen F610 and it works exactly as wacom. No issues at all! Krita rules! I love this project!

Great to hear! Have fun painting!

Doing a bit of google searching on the subject, it seems like most of the issues with Krita and pressure sensitivity come from non-wacom tablets. I'm confused because I'm having the same issue (tablet itself works in Krita, but I can't seem to get pressure), but I have a Wacom Bamboo. It's working just fine in GIMP and MyPaint, but not in Krita, which seems to be the issue described in most of the bug reports for non-Wacom tablets...so I'm not sure why my Wacom tablet isn't working right, either.

I'm using Kororaa 17 (based on Fedora) and my tablet worked out of the box for everything else, it's just Krita that I can't seem to get to detect pressure. It's Krita 2.4.3 and KDE 4.8. Any help would be appreciated - I'm new to Krita, but it seems like it could be the most ideal Linux equivalent of Paint Tool Sai that I use on Windows. If I could get pressure, that is.

I'm not too familiar with Fedora, but there are certain patched revisions of X11 and Qt that kill Wacom support in Qt. *Buntu suffered most of that, in the past (12.04 seems fine), but other distributions might get those problems as well, especially if they use the custom patches that create multi-touch support in X11 and Qt.

Hmm...I seem to have fixed it - through GIMP, somehow!! By default GIMP 2.8 has some preloaded brush dynamics, ex. pen pressure controls line opacity...I decided to create the one most relevant to me, where pen pressure controls the line's size, but it didn't seem to have any effect even though the preloaded brush dynamics worked as intended with the pen's pressure. I found this on Ask Ubuntu (even though it's for GIMP 2.6, it still worked), and setting my device to Screen Mode as explained here got my brush dynamics working in GIMP as intended.

To my surprise, when I launched Krita to see if it had a similar setting that might solve my problem, I discovered that automatically I was getting pressure support, without having to mess with Krita-specific options. I'm guessing maybe the dialogue GIMP launched was connected to X as a whole and not just GIMP/GTK, and so Krita was now also able to detect my tablet in 'screen mode'. Very strange, especially since GIMP and MyPaint were both responding to pressure beforehand (as I said, GIMP was still allowing pressure to control opacity and such, it just didn't play nice when I tried to set it to control stroke size), but I didn't do anything else to Krita that should have fixed the issue, so I'm guessing this is what did it.



Maybe this will help someone else who might be experiencing problems with pressure in Krita. But for now, I'm just happy I got it to work, and now I can happily experiment with Krita!!

That's rather astonishing . But yes, it's possible that gimp might have enabled something that fedora disables by default in their config dialog. Wish what it was...

I'm pretty sure I had pressure sensitivity in a recent version of Krita, but today I was using it and found this has gone. As far as I can see there is now no Krita configuration for tablets, and there is no system-wide configuration on Fedora either (only a GUI for assigning buttons, nothing for per-app settings, or enabling or disabling pressure sensitivity).

From reading about Qt issues it seems like not only is this issue down to poor Qt support, but that tablet support may soon be removed altogether from Qt! See http://www.phoronix.com/scan.php?page=news_item&px=MTE3OTU

So my questions are:

1. Is there any way to enable pressure sensitivity in Krita / Qt apps right now (I'm running Qt 4.8 on Fedora 17, with Krita 2.5)?
2. Is there any future for Krita if Qt drops wacom support, given that Krita is a (brilliant) tablet-centric app?

1: Consider filing a bug report for Fedora. It's very likely that some change there broke it again, happens quite regularly.

2: Take that with a grain of salt. There are lots of developers using Qt's tablet api, so I'm hopeful that there will be a solution. Even in the worst case that the tablet support wouldn't work any longer, there are ways to readd it to Krita and we have done that before. This doesn't effect the future of Krita in any way.

slangkamp wrote:1: Consider filing a bug report for Fedora. It's very likely that some change there broke it again, happens quite regularly.

2: Take that with a grain of salt. There are lots of developers using Qt's tablet api, so I'm hopeful that there will be a solution. Even in the worst case that the tablet support wouldn't work any longer, there are ways to readd it to Krita and we have done that before. This doesn't effect the future of Krita in any way.

That's very reassuring to know. I'm just learning Krita and glad you guys are in it for the long term. With this in mind I'll chase up the pressure bug I'm experiencing. Thanks!