Bug 447006

Summary:	Regression: Different presets for different pens
Product:	[Applications] krita	Reporter:	Vladimir Savic <vladimir.firefly.savic>
Component:	* Unknown	Assignee:	Krita Bugs <krita-bugs-null>
Status:	RESOLVED INTENTIONAL
Severity:	normal	CC:	halla
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Vladimir Savic 2021-12-15 00:17:44 UTC

SUMMARY
I own two different Wacom pens and would like to use them as real-life brushes - switching pen to switch painting presets. It turned out that this functionally was present in Krita in the past. For the background take a look at the following forum post: https://krita-artists.org/t/different-pens-for-different-brushes-in-krita/26518 

After testing Appimage version 4.1.x I can confirm that it is the last version where this function worked. Since Appimage 4.2 it's gone...

I'm using GNOME DE and I confirm that both physical pens are recognized and reported by the corresponding System Settings module. Krita also acknowledges two pens and shows unique "Stylus pen id:" numbers, but it refuses to assign a Brush presets to a pan.

Comment 1 Halla Rempt 2021-12-15 09:24:34 UTC

This was intentionally removed:

commit 20cb1f86e1e129a64c111d2db3522013f534d83c
Author: Boudewijn Rempt <boud@valdyas.org>
Date:   Mon May 27 11:22:37 2019 +0200

    Do not use the stylus id to set the preset
    
    Using the stylus' unique id to set the preset allowed users to
    have different presets for e.g. an art pen and a normal stylus.
    
    However, we are seeing random stylus id's for the same actual
    stylus being reported, which means that this feature is completely
    broken.
    
    BUG:407659
    BACKPORT:krita/4.2

Comment 2 Vladimir Savic 2021-12-15 11:47:06 UTC

Does this still hold true? Can we recheck somehow?
I wouldn't mind having some kind of preferences switch for intentionally taking a risk. Even buried deeply in some .config file. :)

Comment 3 Halla Rempt 2021-12-15 12:10:47 UTC

Well, it's a LOT of work: revert the commit, add instrumentation, then make logs and check that over the course of several driver versions on macOS, Linux and Windows the ID of pens are stable we could consider reverting the commit and re-adding the feature. Not gonna lie: I am not looking forward to doing that myself.

Comment 4 Halla Rempt 2021-12-15 12:22:45 UTC

It took from 2016 to 2019 to find out what was up. Here's a video deevad made of the issue:

https://www.peppercarrot.com/extras/videos/2019-05-17_random-preset-switch-bug_investigation-A.mp4

Comment 5 Vladimir Savic 2021-12-15 13:02:52 UTC

Thanks for the follow-up. It's nasty, yes! Wait... And that happened with only one stylus? @deevad didn't even use two pens!? Really odd one from Qt...

Comment 6 Halla Rempt 2021-12-15 13:43:35 UTC

I suspect that the driver now and then thinks it's time to reset the id all by its lonesome.