Bug 334282

Summary: The Airbrush rate option doesn't seem to work properly on a Intuous 3
Product: [Applications] krita Reporter: wolthera <griffinvalley>
Component: Tablets (tablet issues are only very rarely bugs in Krita!)Assignee: Krita Bugs <krita-bugs-null>
Status: RESOLVED WAITINGFORINFO    
Severity: normal CC: animtim, dimula73, halla, info, mirandagraphic, prodanov
Priority: NOR    
Version First Reported In: git master (please specify the git hash!)   
Target Milestone: ---   
Platform: unspecified   
OS: Unspecified   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description wolthera 2014-05-03 15:12:39 UTC 
The Airbrush option in the Pixel brush engine should build-up the stroke as the stylus is held in one place.
This functionality works fine with a mouse, and with the wacom ISDv4 E3 screen, but seems to hamper with the Intuous 3. This behaviour was found both on a Windows 7 64bit device, and a Ubuntu 13.10 64bit device.

From the forum thread: http://forum.kde.nl/viewtopic.php?f=281&t=120924

Reproducible: Always
Comment 1 Dmitry Kazakov 2014-05-05 07:49:07 UTC 
Yes, this is a Krita problem that appeared after better tablet support
Comment 2 Dmitry Kazakov 2014-05-05 08:07:41 UTC 
Ok, we have three options how Airbrushing can work:

1) The brush usually paints using "Spacing" parameter, that is depending on the distance covered by the stylus. When the stylus stops, the timer starts painting dabs. That is how it works now.

2) The brush paints with both "Spacing" and "Airbrush" options at the same time. Sometimes it can generate spurious dabs though, which might look buggy.

3) The "Spacing" is disabled and the dabs are painted only based on the internal timer.
Comment 3 wolthera 2014-05-05 12:31:39 UTC 
,
Comment 4 wolthera 2014-05-05 12:33:35 UTC 
My intuition is to have the dabs set by timer when using the airbrush, because that is similar to how real-life airbrushes work, however, I am not sure if this is fully expected behaviour.

I've added Animtim, Deevad and Ramon to the cc-list, so they can weight in as users.
I'll notify gwenouile of it as well.
Comment 5 Nik Prodanov 2014-05-09 15:15:29 UTC 
I always thought "spacing" meant the timer frequency... There is no apparent benefit to using "travelled distance" since that's not how an airbrush works. I vote for number 3.
Comment 6 Halla Rempt 2015-02-03 19:14:30 UTC 
Should be fixed in

commit 142b953c4d0f6b197435cfdcf424f88796e57c4c
Author: Dmitry Kazakov <dimula73@gmail.com>
Date:   Tue Feb 3 13:18:43 2015 +0300

    This patch should probably fix Wacom Airbrush devices
    
    This patch adds recognition of the device type on Linux, and tries to
    fix the tangential pressure parameter.
    
    If you happen to have an Airbrush device, please do test whether
    tangential pressure starts working correctly.
    
    Most probable bug: the range of the tangential pressure might be
    wrong, since I don't know in which limits it is linked in the driver.
    If you see any problems with it, please generate an event log file
    for moving the button in all directions slowly. Here is a manual how
    to do that:
    
    https://answers.launchpad.net/krita-ru/+faq/2495
    
    Thanks arturg for providing initial patches!
    
    CCBUG:343545
    CCMAIL:kimageshop@kde.org

Please check and if so, close!