Bug 378244

Summary: connected stroke on lenovo miix 700
Product: [Applications] krita Reporter: Filippo Rossoni <filippo.rossoni>
Component: Tablets (tablet issues are only very rarely bugs in Krita!)Assignee: Krita Bugs <krita-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: alvin, dimula73
Priority: NOR    
Version First Reported In: 3.1.2   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: tablet log 1 draw directly 2 draw directly 3 wait cursor 4 between hover distance
stroke result
strange behavior 2

Description Filippo Rossoni 2017-03-29 16:10:08 UTC 
Created attachment 104798 [details]
tablet log 1 draw directly 2 draw directly 3 wait cursor 4 between hover distance

I have a Lenovo miix 700 with windows 10 
it has an ELAN screen compatible with wacom aes pen but not with wacom driver

I use a wacom Bamboo Smart (version for select tablets and 2-in-1 convertible devices)

accordind to this site
http://arthurhwalker.tumblr.com/post/139973019568/lenovo-miix-700-review
to make krita recognize the pressure I installed microsoft wintab driver for surface 4 (v 1.0.0.20)

the problem is if I draw multiple stroke i get a connection with previous stroke with a soft line

If i wait the cursor to appear before drawing a stroke I get no problem

If I stay within the hover distance (4 5 mm) between 2 strokes I get no problem
Comment 1 Filippo Rossoni 2017-03-29 16:11:10 UTC 
Created attachment 104799 [details]
stroke result
Comment 2 Dmitry Kazakov 2017-03-29 16:25:13 UTC 
The last two 'ifs' sound quite interesting...
Comment 3 Dmitry Kazakov 2017-03-29 16:26:38 UTC 
I have a feeling that the driver generates a TabletPress event after every "TabletEnterProximity" event. Which sounds weird, but correlates well with tablet log and the second 'if'
Comment 4 Filippo Rossoni 2017-03-29 16:38:20 UTC 
I'm not shure about last if becouse I move the pen slowly to not leave the shallower hover distance
Comment 5 Filippo Rossoni 2017-03-29 22:50:42 UTC 
Created attachment 104805 [details]
strange behavior 2

another strange behavior 
1 draw stroke with stylus
2 draw stroke with mouse
3 draw stroke with stylus

stroke 3 connected to stroke 1
Comment 6 Alvin Wong 2017-09-05 16:30:41 UTC 
My guess on what seems to be happening is that, whenever the stylus is pressed too quickly, it has not yet updated the stylus coordinate so it sends a tablet press event with the last remembered coordinates before the stylus last left the hover proximity. It can be guessed from the fact that there aren't any tablet hover events (TabletMove with btns=0) before the tablet press events that sends the wrong coordinates.

It can be worked around by waiting for the hover events to be sent, as observed.

Unfortunately, since it is a driver (or hardware) issue, we can't fix it on Krita's end.