Re: [TurboVNC-Users] Can wacom support be made to work on non wacom tablet?

[DRC]

It should be possible, yes.  TurboVNC uses an RFB extension called "GII" that is basically designed as a remote interface for X Input.  The Linux TurboVNC Viewer clones any X Input extended pointer devices from the client into the TurboVNC Server session.  It sounds like it is doing that properly, but perhaps there is some issue with the translation of events.  Can you send me the output of

    xinput --list --long

both on the client and in the TurboVNC Server session?

Also double check the Inkscape settings on the server.  I know that, with GIMP, it is necessary to map the X Input devices to pressure and other parameters within the GIMP settings, and you have to do that once for your account on the server before remote pressure events can be properly interpreted by that application.

On 8/15/19 3:28 PM, joakimv wrote:

I Have a hp laptop with a pen screen.

The pen screen isnt wacom but some other type of generic device, a little unclear which.

On the laptop I can use the pen screen pressure sensitivity in inkscape for instance.

There, the device is reported as xwayland-stylus.

Remotely using turbovnc, I also see xwayland-stylus in the remote inkscape, but pressure events are not propagated.

Is there some type of workaround for this?

Regards

/Joakim

[joa...@verona.se]

DRC <d...@virtualgl.org> writes:

> It should be possible, yes. TurboVNC uses an RFB extension called "GII" that is basically designed as a remote interface for X Input. The Linux TurboVNC Viewer clones any X Input extended pointer devices from the client into the
> TurboVNC Server session. It sounds like it is doing that properly, but perhaps there is some issue with the translation of events. Can you send me the output of
>
> xinput --list --long
>
> both on the client and in the TurboVNC Server session?
>
> Also double check the Inkscape settings on the server. I know that, with GIMP, it is necessary to map the X Input devices to pressure and other parameters within the GIMP settings, and you have to do that once for your account on the
> server before remote pressure events can be properly interpreted by that application.

I was able to get pressure sensitivity working in Gimp, on the server.
So at least something is working properly.

Now that I changed to X rather than Wayland on the client, the devices
are reported as Wacom.

Inkscape and Krita are still missbehaving.

Inkscape shows the extended devices, but I cant seem to enable them,
which is different on the client side.

I attach the xinput logs below.

[DRC]

Ah, OK.  I think you're running into this issue, then, which only affects applications that use Qt5:

https://github.com/TurboVNC/turbovnc/issues/154#issuecomment-446469303

Qt5 is overly strict in its support for extended input devices.  It expects the valuator for pressure to be literally called "Abs Pressure", and if it can't find a valuator with that name, it doesn't properly read pressure events.  The current workaround is to start the TurboVNC Server with -virtualtablet, but I expect to fix this issue properly in TurboVNC 3.0 by dropping support for X Input v1:

https://github.com/TurboVNC/turbovnc/issues/156

On 8/15/19 3:28 PM, joakimv wrote:

 I Have a hp laptop with a pen screen.

 The pen screen isnt wacom but some other type of generic device, a little unclear which.

 On the laptop I can use the pen screen pressure sensitivity in inkscape for instance. 

 There, the device is reported as xwayland-stylus.

 Remotely using turbovnc, I also see xwayland-stylus in the remote inkscape, but pressure events are not propagated.

 Is there some type of workaround for this?

 Regards
 /Joakim

[joa...@verona.se]

DRC <d...@virtualgl.org> writes:

> Ah, OK. I think you're running into this issue, then, which only affects applications that use Qt5:
>
> https://github.com/TurboVNC/turbovnc/issues/154#issuecomment-446469303
>
> Qt5 is overly strict in its support for extended input devices. It expects the valuator for pressure to be literally called "Abs Pressure", and if it can't find a valuator with that name, it doesn't properly read pressure events.
> The current workaround is to start the TurboVNC Server with -virtualtablet, but I expect to fix this issue properly in TurboVNC 3.0 by dropping support for X Input v1:
>
> https://github.com/TurboVNC/turbovnc/issues/156

Thanks, I will look into this!

--
Joakim Verona
joa...@verona.se

[joa...@verona.se]

DRC <d...@virtualgl.org> writes:

> Ah, OK. I think you're running into this issue, then, which only affects applications that use Qt5:
>
> https://github.com/TurboVNC/turbovnc/issues/154#issuecomment-446469303
>
> Qt5 is overly strict in its support for extended input devices. It expects the valuator for pressure to be literally called "Abs Pressure", and if it can't find a valuator with that name, it doesn't properly read pressure events.
> The current workaround is to start the TurboVNC Server with -virtualtablet, but I expect to fix this issue properly in TurboVNC 3.0 by dropping support for X Input v1:
>
> https://github.com/TurboVNC/turbovnc/issues/156

I tried setting the -virtualtablet flag.

- The automatic desktop resize when resizing the turbovnc client window
stopped working. The remote desktop is a fixed size.

- Pressure sensitivity in Krita started working.

- Pressure sensitivity in Inkscape still didnt work.

I think Inkscape uses GTK 2. I can maybe try recompiling it with gtk3 to
see if it makes a difference (but im not sure the inkscape devs finished
their gtk3 port yet.)

Regards
/Joakim

--
Joakim Verona
joa...@verona.se

[DRC]

-virtualtablet should have no effect on remote desktop resizing. The
company that paid for the remote X Input/Wacom feature uses remote
desktop resizing in their deployment, and there have been no issues
reported with that.

If I recall, I did encounter some problems when trying to use a Wacom
tablet remotely with GIMP on a GTK 2 machine (CentOS 6, specifically),
so that might have something to do with the problem you are
experiencing. I will try to bring up Inkscape.

[joa...@verona.se]

DRC <d...@virtualgl.org> writes:

> -virtualtablet should have no effect on remote desktop resizing. The
> company that paid for the remote X Input/Wacom feature uses remote
> desktop resizing in their deployment, and there have been no issues
> reported with that.

Ok, I will try to see if it can be replicated.

>
> If I recall, I did encounter some problems when trying to use a Wacom
> tablet remotely with GIMP on a GTK 2 machine (CentOS 6, specifically),
> so that might have something to do with the problem you are
> experiencing. I will try to bring up Inkscape.

Thanks!

Meanwhile, I compiled Inkscape from source, and it behaves the same
way. I can see the wacom devices in inkscapes input device dialog, but
fiddling with the devices there makes no difference, pressure
sensitivity is not received properly in the application.

> On 8/16/19 4:40 PM, joa...@verona.se wrote:
>> DRC <d...@virtualgl.org> writes:
>>
>>> Ah, OK. I think you're running into this issue, then, which only affects applications that use Qt5:
>>>
>>> https://github.com/TurboVNC/turbovnc/issues/154#issuecomment-446469303
>>>
>>> Qt5 is overly strict in its support for extended input devices. It expects the valuator for pressure to be literally called "Abs Pressure", and if it can't find a valuator with that name, it doesn't properly read pressure events.
>>> The current workaround is to start the TurboVNC Server with -virtualtablet, but I expect to fix this issue properly in TurboVNC 3.0 by dropping support for X Input v1:
>>>
>>> https://github.com/TurboVNC/turbovnc/issues/156
>>
>> I tried setting the -virtualtablet flag.
>>
>> - The automatic desktop resize when resizing the turbovnc client window
>> stopped working. The remote desktop is a fixed size.
>>
>> - Pressure sensitivity in Krita started working.
>>
>> - Pressure sensitivity in Inkscape still didnt work.
>>
>> I think Inkscape uses GTK 2. I can maybe try recompiling it with gtk3 to
>> see if it makes a difference (but im not sure the inkscape devs finished
>> their gtk3 port yet.)
>>
>> Regards
>> /Joakim

--
Joakim Verona
joa...@verona.se

[joa...@verona.se]

DRC <d...@virtualgl.org> writes:

> -virtualtablet should have no effect on remote desktop resizing. The
> company that paid for the remote X Input/Wacom feature uses remote
> desktop resizing in their deployment, and there have been no issues
> reported with that.
>
> If I recall, I did encounter some problems when trying to use a Wacom
> tablet remotely with GIMP on a GTK 2 machine (CentOS 6, specifically),
> so that might have something to do with the problem you are
> experiencing. I will try to bring up Inkscape.

Ok, I tried again, and now everything works much better!

This is what worked for me:

- tvncserver:

VNCSERVERS="1:joakim"
VNCSERVERARGS[1]="-virtualtablet -geometry 1920x1080 -nohttpd -localhost"

- fedora 30 in both ends

- turbovnc, external ssh due to funky ssh setup

- gnome desktop

- inkscape, gimp and krita where all tested, and works this time.

- desktop resizing works

I'm quite sure I tested this exact same configuration before sending my
mail last time, but now the results are different, for whatever reason.

Anyway, thanks again!

>
> On 8/16/19 4:40 PM, joa...@verona.se wrote:
>> DRC <d...@virtualgl.org> writes:
>>
>>> Ah, OK. I think you're running into this issue, then, which only affects applications that use Qt5:
>>>
>>> https://github.com/TurboVNC/turbovnc/issues/154#issuecomment-446469303
>>>
>>> Qt5 is overly strict in its support for extended input devices. It expects the valuator for pressure to be literally called "Abs Pressure", and if it can't find a valuator with that name, it doesn't properly read pressure events.
>>> The current workaround is to start the TurboVNC Server with -virtualtablet, but I expect to fix this issue properly in TurboVNC 3.0 by dropping support for X Input v1:
>>>
>>> https://github.com/TurboVNC/turbovnc/issues/156
>>
>> I tried setting the -virtualtablet flag.
>>
>> - The automatic desktop resize when resizing the turbovnc client window
>> stopped working. The remote desktop is a fixed size.
>>
>> - Pressure sensitivity in Krita started working.
>>
>> - Pressure sensitivity in Inkscape still didnt work.
>>
>> I think Inkscape uses GTK 2. I can maybe try recompiling it with gtk3 to
>> see if it makes a difference (but im not sure the inkscape devs finished
>> their gtk3 port yet.)
>>
>> Regards
>> /Joakim

--
Joakim Verona
joa...@verona.se

[DRC]

Glad to hear it.  My favorite problems are the ones that solve themselves.  Please let me know if either problem (remote desktop resizing not working or Inkscape pressure events not working) resurfaces.  I have seen, on extremely rare occasions, the viewer and server fail to negotiate remote desktop resizing capabilities, but I haven't ever been able to nail down the exact cause.  I thought that 5cb50b8f8732d0d79689e207fd67bc9692c38e69 in TurboVNC 2.2.1 fixed those issues.