Pressure sensitive tablet: stylus paints off-cursor in Gimp and Inkscape

[Hernando Torque]

Binary package hint: wacom-tools

When activating the "Wacom Bamboo" device in Gimp or Inkscape (http://img.xrmb2.net/images/599671.png), stylus and cursor position don't match. This happens on a notebook with VESA driver, no twin view or similar setup.

Wacom Bamboo device:
- mode "Disabled": stylus and cursor position match, but only works like a cursor (no pressure sensitivity).
- mode "Screen": stylus has a fixed offset but works like expected.
- mode "Window": stylus offset varies.

See attached screen casts.

This worked flawlessly in Ubuntu 9.04.

ProblemType: Bug
Architecture: i386
Date: Fri Aug 7 14:19:57 2009
DistroRelease: Ubuntu 9.10
MachineType: Zepto Znote
Package: xserver-xorg-input-wacom 1:0.8.3.2-1ubuntu1
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-5-generic root=UUID=46ae9ffe-1df7-4a98-a602-25b2b4aca963 ro crashkernel=384M-2G:64M,2G-:128M bootchart=disable
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-5.24-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu5
 libgl1-mesa-glx 7.5-1ubuntu1
 libdrm2 2.4.12-1ubuntu1
 xserver-xorg-video-intel 2:2.8.0-0ubuntu2
 xserver-xorg-video-ati 1:6.12.99+git20090629.f39cafc5-0ubuntu5
SourcePackage: wacom-tools
Uname: Linux 2.6.31-5-generic i686
dmi.bios.date: 06/18/07
dmi.bios.vendor: ZEPTO
dmi.bios.version: Z1.23
dmi.board.name: MPAD-MSAE Customer Reference Boards
dmi.board.vendor: Acer,inc
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 1
dmi.chassis.vendor: Acer,inc
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnZEPTO:bvrZ1.23:bd06/18/07:svnZepto:pnZnote:pvr6214W:rvnAcer,inc:rnMPAD-MSAECustomerReferenceBoards:rvrNotApplicable:cvnAcer,inc:ct1:cvrN/A:
dmi.product.name: Znote
dmi.product.version: 6214W
dmi.sys.vendor: Zepto
fglrx: Not loaded
system:
 distro: Ubuntu
 architecture: i686kernel: 2.6.31-5-generic

[Hernando Torque (htorque)]

I only have a Jaunty Alpha Live-CD to test and it definitely works (also Inkscape's calligraphy tool) with:

- wacom-tools/xserver-xorg-input-wacom 1:0.8.2.2-0ubuntu2
- kernel 2.6.28-4.9

[Hernando Torque (htorque)]

More information on the offset:

*) Screen mode
The amount of x- and y-offset equal the space between window border and visible canvas (image canvas + space around), like ruler/menu bar:

http://img.xrmb2.net/images/770432.png

Removing the rulers reduces the offset by the rulers widths:

http://img.xrmb2.net/images/945369.png

*) Window mode
The stylus' x- and y-position within the visible canvas area seems to be equal to the relative position of the cursor on screen, e.g.
cursor position x (on screen) = screen width * 0.75
cursor position y (on screen) = screen height * 0.5
=>
stylus position x (within canvas) = canvas width * 0.75
stylus position y (within canvas) = canvas height * 0.5:

http://img.xrmb2.net/images/171503.png

[ScislaC (scislac)]

It seems like this might not be an issue only for Wacom tablets.

Someone has the same issue with a "Genius" tablet, which would not use wacom-tools:
http://ubuntuforums.org/showpost.php?p=869907&postcount=1

[ScislaC (scislac)]

Sorry, wrong link... Here is the correct one:

http://ubuntuforums.org/showpost.php?p=7644570&postcount=1

[ScislaC (scislac)]

Sorry about commenting again, I have an Intuos 2 tablet which has the same issue, so this is definitely not a Bamboo issue only.

[ScislaC (scislac)]

Hernando,

The Inkscape issue you see there is actually an unrelated inkscape bug. Adjust the width slider to see if it fixes the problem for you. If it does not, try deleting your inkscape preferences file. The problem has since been fixed in Inkscape SVN, so it will not be in 0.47.

[Bryce Harrington (bryce)]

I'm really doubting this could be a bug in -vesa. Vesa doesn't touch on the input system much. I doublechecked the changelogs just in case and saw nothing related to input/coordinate handling. Further, confirmed with ScislaC that his issue was seen on -ati.

Most of the input system changes from Jaunty to Karmic are in the xserver, so I think this is a better guess than -vesa. Particularly so if ScislaC sees the same bug on input drivers other than wacom.

[Hernando Torque (htorque)]

Doesn't matter if I use vesa, nv, nouveau, or the binary blob. I also remember reading somewhere (not uf.org) that it happens with ATI drivers.

@ ScislaC: Thanks for the info about inkscape. The lagging stayed even at width 1, so I guess the fix isn't in Karmic yet.

[Juan Sebastián Marulanda (juanchito2006)]

Greetings, I'm the poster of the linked thread, and I confirm this still happening with my G-Pen 4500. I'm using the -intel driver.

[Juan Sebastián Marulanda (juanchito2006)]

I forgot, I'm using the wizardpen driver for my tablet.

[Rewben (mastodront)]

Just came in to say that I have the same problem as the posters above.

I have a Wacom Graphire (sorry but I can't tell if it's 3 or 4, the model is CTE-440) and both Inkscape and Gimp has an annoying offset.

I've tried it on two computers;

My stationary, which runs Kubuntu Karmic (64) Alpha 4. I'm using the nvidia driver, and have a twinview setup on this computer. I'm pretty sure it worked just fine when I ran Ubuntu 9.04 (don't use my wacom frequently) but I booted up an 8.10 live-cd and it worked perfectly there.

My other computer is a laptop running Kubuntu Karmic (32), but an older build, probably from early June. This one is using an Intel driver (x3100 is the chip if I remember correctly). It has the exact same problem as the other computer, and because the install is a couple of months old, the problem should be too.

For what it's worth, I'm attaching a screen recording similar to Mr Torques'. I used Inkscape for it, but the result is the same as in Gimp.

[Mathieu Comandon (strycore)]

I confirm this bug is related to window borders. This bug also occurs in MyPaint with one exception : When in fullscreen mode (by pressing F11) , the screen is just one big drawing area and the tablet works as expected.

I wish I had a clue for what to do to analyse the problem further. I could inspect the diffs between Jaunty and Karmic but the origin of the problem still isn't clear. It might also be the window decorator's fault (but I doubt it)

[Mathieu Comandon (strycore)]

The wacom-tools package can be uninstalled and the bug still is the same. This is really an issue at a lower level (driver or xserver)

[ScislaC (scislac)]

I'm wondering if this is actually a GTK issue... it definitely relates to other widgets causing a canvas offset. In Inkscape when you enable or disable toolbars, rulers, or the toolbox it offsets the coords on-canvas by that same amount.

[ScislaC (scislac)]

Alright... it appears to be the bug linked to now.

http://bugzilla.gnome.org/show_bug.cgi?id=588649

If anyone here has the appropriate bugsquad permissions in bugzilla, please do change the status there appropriately.

[Loïc Martin (loic-martin3)]

Just to note that in Karmic with latest updates and Wacom 0.8.4.1 (Timo's package, soon in the repos), the stylus paints way off cursor in Inkscape, but in Gimp it's not off cursor at all (for example, when painting with the Paintbrush tool, the painting appears exactly inside the little circle that represents the brush.

[RZ (rufei-z)]

I can confirm that GIMP paints inside the circle with an up-to-date Karmic and Wacom Driver 0.8.4-2. However, the circle in the paintbrush tool (and any other tool with the circle) is off-cursor for me.

[ScislaC (scislac)]

RZ,

Correct... it paints inside the circle, but the circle is offset from where it should be.

[Mackenzie Morgan (maco.m)]

With latest updates in Karmic it's in exactly the right spot on MyPaint
(another GTK+ app where it was incorrectly placed--someone from Inkscape asked
that I test with it as well, though it's not in Ubuntu).

[ScislaC (scislac)]

Mackenzie,

Unfortunately my Tablet is packed up so I can't verify, but in MyPaint, is it also using the extended tablet features such as Pressure?

[Mackenzie Morgan (maco.m)]

Yes. A couple weeks ago it drew incorrectly in MyPaint just like in the
others. As of when I tried it on Friday, it was working properly.

[Juan Sebastián Marulanda (juanchito2006)]

In GIMP, there seems to be a lazy solution, moving the circle cursor according to the offset. In Inkscape, the issue persists.

[Hernando Torque (htorque)]

Mackenzie, did you set the mode for input devices in MyPaint to either "screen" or "window" (Edit > Settings... > Pressure tab)?

I see no change in MyPaint, Gimp, and Inkscape.

[Mackenzie Morgan (maco.m)]

MyPaint is set to "screen" (which is its default).

[Rewben (mastodront)]

Updated my Kubuntu Karmic today, and sadly the problem remains for me in both Inkscape and Gimp.

[Mathieu Comandon (strycore)]

This bug has no reason to be fixed yet. Carlos Garnacho has released 3 patches yesterday for libgtk, and these patches have not yet been applied on Karmic's libgtk.

I will try them out today and also I will try to repackage the patched libgtk and upload it on my PPA if it fixes the bug.

[Mathieu Comandon (strycore)]

Ok, i've applied the patch and Gimp, Inkscape and MyPaint are behaving perfectly with my Wacom tablet.
I've uploaded the fixed libgtk to my PPA : https://launchpad.net/~strycore/+archive/ppa . When Launchpad has built the binaries, you're good to go.

[Mathieu Comandon (strycore)]

Since the patch works, here's the debdiff so it can be merged in the main repos

[Loïc Martin (loic-martin3)]

Matthieu's debdiff works for me on an Intuos3 tablet with either Inkscape of the Gimp. Input 100% matches the cursor, with pressure still there as expected.

It also seems to have fixed Bug #433121, which resulted on an immediate Inkscape segfault that is not happening any more with the patches in the debdiff.

[Loïc Martin (loic-martin3)]

Note that the patches only fix the Screen mode (most used mode, only way to get a decent precision with the devices), the Window mode still draws off cursor. But it's by far the mode where it's important (even though fixing the behavior in Window mode would still be a good thing).

[Stefan van der Walt (stefanv)]

Thanks very much, Mathieu! I can also confirm that the fix works.

[ScislaC (scislac)]

I see that GTK 2.18 is in the repos and unfortunately my tablet is packed away still, can anyone comment on if the fix is in this release?

[Juan Sebastián Marulanda (juanchito2006)]

Seems fixed for me in 2.18.

[Loïc Martin (loic-martin3)]

Same, fixed with libgtk2.0-0 2.18.

[Tom Jaeger (thjaeger)]

We still need 2.18.1 for a proper fix that works with devices using the evdev driver.

[kaeru (kaeru)]

Does it work for window mode as well?

At least for me in Window mode, for both Inkscape and GIMP with libgtk 2.18.3-1ubuntu2.2 the offset issue is still there.

[Juan Sebastián Marulanda (juanchito2006)]

It doesn't work in Window mode, it's a known issue.

On Thu, Feb 4, 2010 at 9:05 PM, kaeru <email address hidden> wrote:
> Does it work for window mode as well?
>
> At least for me in Window mode, for both Inkscape and GIMP with libgtk
> 2.18.3-1ubuntu2.2 the offset issue is still there.
>
> --
> Pressure sensitive tablet: stylus paints off-cursor in Gimp and Inkscape
> https://bugs.launchpad.net/bugs/410267
> You received this bug notification because you are a direct subscriber
> of the bug.
>

--
Juan S. Marulanda
aka Richard Wolf VI
aka Pequeñín