#136 Glitches - Xinput + Wacom

v1.0_(example)
open
nobody
xinput (1)
5
2014-07-06
2014-07-02
Leandro Heck
No

Using Xinput 0.4.8 with Wacom Pen, the lines have an odd behavior when the pen goes out of the tablet as shown in the attachment.

1 Attachments

Discussion

  • Denis Auroux
    Denis Auroux
    2014-07-02

    Was it any different in 0.4.7? i.e., is this a new problem in 0.4.8? I
    don't think the part of the code that reads pressure data to assign
    stroke width has changed at all. On my system I don't observe this
    behavior, but wacom pressure calibration seems to vary a LOT from a
    tablet PC pen to the next one.

    Denis

     
  • Leandro Heck
    Leandro Heck
    2014-07-02

    Yes, this happens only in 0.4.8.
    In 0.4.7 I never noticed the problem.
    I did not find a menu to enable the pressure.
    It is enabled by default.
    There was a menu for it?

     
    • Denis Auroux
      Denis Auroux
      2014-07-02

      On 07/01/2014 07:20 PM, Leandro Heck wrote:

      Yes, this happens only in 0.4.8.
      In 0.4.7 I never noticed the problem.
      I did not find a menu to enable the pressure.
      It is enabled by default.
      There was a menu for it?

      Yes:
      Options -> Pressure sensitivity in 0.4.7,
      Options -> Pen and touch -> Pressure sensitivity in 0.4.8.

      Can you e-mail me (myusername@math.berkeley.edu) sample xoj files
      containing a few pressure-sensitive strokes you drew with 0.4.7, and
      with 0.4.8 ? (without the problem, and with the problem) ? I suspect
      your pen might report a pressure of 0.00 as it is about to leave the
      screen, which has never happened for me on any of my machines. In this
      case, a bugfix introduced recently to handle devices that always report
      a pressure of 0.00 might be causing the behavior -- but I'd like to check.

      Thanks,
      Denis

       
  • Leandro Heck
    Leandro Heck
    2014-07-02

    True! There is the setting... then by disabling the pressure this behavior disappear. :)

     
  • Jim
    Jim
    2014-07-02

    Just to follow up, I see the same behaviour with 0.4.8 on a Fujitsu T900 (which has a wacom screen and a touchscreen). If I can be of any assistance on this (running tests on yet another device, etc) just let me know.

    On that laptop the behaviour is more sporadic/subtle than what Leandro is seeing; I didn't notice it until I read his bug report.

     
  • Denis Auroux
    Denis Auroux
    2014-07-02

    The regression should be fixed in the CVS and GIT repository: if the device reports zero pressure, we no longer view the value as invalid, unless no positive pressure data has been received on this stroke.

    (For me this restores the same behavior on pen strokes as for version 0.4.7. The end of my strokes still sometimes looks funny even with the patch, but as far as I can tell it is a bug in linuxwacom for my tablet model causing the driver to report full pressure when the pressure is actually fairly light).

    If you are affected by this bug, please try recompiling from the code in the repository and see if this fixes the issue (i.e., pressure sensitivity works as well as in 0.4.7).

    Denis

     
  • Jim
    Jim
    2014-07-02

    Looks good to me on my system.

    I (apparently) am the current xournal SlackBuild maintainer. If "everyone" is happy with the CVS/GIT version, are you planning to create a 0.4.9 version? (If not, I'll create a patch set for an updated SlackBuild.)
    Thanks.

     
    • Denis Auroux
      Denis Auroux
      2014-07-02

      On 07/02/2014 08:13 AM, Jim wrote:

      Looks good to me on my system.

      I (apparently) am the current xournal SlackBuild maintainer. If
      "everyone" is happy with the CVS/GIT version, are you planning to create
      a 0.4.9 version? (If not, I'll create a patch set for an updated
      SlackBuild.)

      This bug is not significant enough in my book to warrant a 0.4.9 version
      so soon after 0.4.8 (released just two days ago). I think it would be
      great if SlackBuild can update either to 0.4.8 if not done yet or even
      better to 0.4.8 + the latest patches (= the current state of the GIT
      repository). Before there's a further version number change I want to
      fix a number of other outstanding input related issues.

      Best,
      Denis

      --
      Denis Auroux auroux@math.berkeley.edu
      University of California, Berkeley Tel: 510-642-4367
      Department of Mathematics Fax: 510-642-8204
      817 Evans Hall # 3840
      Berkeley, CA 94720-3840

       
  • Skyler
    Skyler
    2014-07-06

    I am also experiencing this on my Lenovo ThinkPad X230i tablet, which has a wacom stylus. I've attached a screenshot of an .xoj file made with both 0.4.7 and 0.4.8, and the .xoj file itself. If you look at the tips of the letters, where my pen strokes become lighter, in 0.4.7, they become smaller and come to a point, whereas in 0.4.8, it seems to make a fat glob when I release the stylus. I'll have to stick to 0.4.7 until this is patched in the official Arch repo.

     
    Last edit: Skyler 2014-07-06
  • Denis Auroux
    Denis Auroux
    2014-07-06

    It is patched in the upstream git and cvs repositories, so if you ask the maintainer for the Arch respository, a new version of the Arch package can probably be made... You can also disable pressure sensitivity...