Non-wacom tablets broken on Blender in linux? #43367

New Issue

Bastien Montagne · 2015-01-22T13:13:14+01:00

Bastien Montagne commented

2015-01-22 13:13:14 +01:00

Disclaimer: I already spent one whole day investigating that, so report will be quite long.

Affects at least Blender 2.69 to 2.73 (and latest master). Suspect it is related to newest Xorg somehow.

Issue

On my OS (debian64 testing, up-to-date), in Blender, is have no pressure when using my tablet (Genius 450). Each stroke gets the init pressure, and keep it until the end.
Same tablet works perfectly under Gimp (not so relevant, afaik GDK uses new X11 device handling) and Krita (which uses very similar code as Blender when handling tablets).

Note I tried another (even more name-less) tablet, with exact same results.

Question 1: can anybody else confirm the issue?

Investigations

Issue is, X11 Ghost does not get 'tablet' events (XDeviceMotionEvent) once pen is down. When pen is only hovering (without being pressed), those events reach ghost without any issue.

Here is a (cleaned up) example of events as processed by GHOST_SystemX11::processEvents:

[...]

pen is hovering tablet...

processEvents:
    TabletEvent
    MotionNotify

processEvents:
    TabletEvent
    MotionNotify

pen goes down

processEvents:
    TabletEvent (p: 473)  <- only time we get some pressure info
    MotionNotify
    ButtonPress

pen is drawing

processEvents:
    MotionNotify

processEvents:
    MotionNotify

[...]

processEvents:
    MotionNotify

pen goes up

processEvents:
    MotionNotify
    ButtonRelease

pen is hovering tablet again...

processEvents:
    TabletEvent
    MotionNotify

processEvents:
    TabletEvent
    MotionNotify

Built krita to add prints there too, and tablet events reach krita in all cases (pressed or hovering pen).

So from this it looks like Blender does (or does not) do something that prevents it to get XDeviceMotionEvent's once pen is pressed. Odd thing is, afaik there were no changes here since my last fix (in 2014/01), and at that time it worked perfectly. So would expect some kind of change in API or behavior of recent X libs.

I also used XGetDeviceMotionEvents to get 'history' of tablet events, and there pressure changes are available. So it’s clearly a problem of not getting some X11 events we should get.

Unfortunately, I’m starting to be short on ideas to try here, not an X11 expert at all… :(

Disclaimer: I already spent one whole day investigating that, so report will be quite long. Affects at least Blender 2.69 to 2.73 (and latest master). Suspect it is related to newest Xorg somehow. # Issue On my OS (debian64 testing, up-to-date), in Blender, is have no pressure when using my tablet (Genius 450). Each stroke gets the init pressure, and keep it until the end. Same tablet works perfectly under Gimp (not so relevant, afaik GDK uses new X11 device handling) and Krita (which uses very similar code as Blender when handling tablets). Note I tried another (even more name-less) tablet, with exact same results. Question 1: can anybody else confirm the issue? # Investigations Issue is, X11 Ghost does not get 'tablet' events (XDeviceMotionEvent) once pen is down. When pen is only hovering (without being pressed), those events reach ghost without any issue. Here is a (cleaned up) example of events as processed by `GHOST_SystemX11::processEvents`: ``` [...] ``` # pen is hovering tablet... ``` processEvents: TabletEvent MotionNotify ``` ``` processEvents: TabletEvent MotionNotify ``` # pen goes down ``` processEvents: TabletEvent (p: 473) <- only time we get some pressure info MotionNotify ButtonPress ``` # pen is drawing ``` processEvents: MotionNotify ``` ``` processEvents: MotionNotify ``` ``` [...] ``` ``` processEvents: MotionNotify ``` # pen goes up ``` processEvents: MotionNotify ButtonRelease ``` # pen is hovering tablet again... ``` processEvents: TabletEvent MotionNotify ``` ``` processEvents: TabletEvent MotionNotify ``` Built krita to add prints there too, and tablet events reach krita in all cases (pressed or hovering pen). So from this it looks like Blender does (or does not) do something that prevents it to get XDeviceMotionEvent's once pen is pressed. Odd thing is, afaik there were no changes here since my last fix (in 2014/01), and at that time it worked perfectly. So would expect some kind of change in API or behavior of recent X libs. I also used `XGetDeviceMotionEvents` to get 'history' of tablet events, and there pressure changes are available. So it’s clearly a problem of not getting some X11 events we should get. Unfortunately, I’m starting to be short on ideas to try here, not an X11 expert at all… :(

Bastien Montagne commented

2015-01-22 13:13:14 +01:00

Changed status to: 'Open'

Bastien Montagne commented

2015-01-22 13:13:14 +01:00

Added subscriber: @mont29

Julian Eisel commented

2015-01-22 16:29:58 +01:00

Added subscriber: @JulianEisel

Julian Eisel commented

2015-01-22 16:29:58 +01:00

Have a Wacom here, so I doubt I can help on the coding side. But I recently learned about a nice tool to print out X11 events called "xev" maybe that's helpful for troubleshooting.

blender-admin commented

2015-01-27 16:23:56 +01:00

This issue was referenced by 0d5ebabe43

This issue was referenced by 0d5ebabe437dcf5ce48685667d479d4706ba9d76

Bastien Montagne commented

2015-01-27 16:30:28 +01:00

Changed status from 'Open' to: 'Resolved'

Bastien Montagne closed this issue

2015-01-27 16:30:28 +01:00

Bastien Montagne commented

2015-01-27 16:30:28 +01:00

Closed by commit 0d5ebabe43.

Closed by commit 0d5ebabe43.

Cédric PAILLE commented

2015-02-10 16:51:39 +01:00

Added subscriber: @CedricPAILLE

Cédric PAILLE commented

2015-02-10 16:51:39 +01:00

Hi,

We had a similar problem here with Wacom tablets, I was able to make the pressure work. The problem is in GHOST_WindowX11, the events are overwritten by the X11's macros (DeviceMotionNotify), once for the sytus and secondly for the eraser case (line 587-607).

Here's the patch:

diff --git i/intern/ghost/intern/GHOST_SystemX11.cpp w/intern/ghost/intern/GHOST_SystemX11.cpp
index d4693e9..1a80efd 100644
--- i/intern/ghost/intern/GHOST_SystemX11.cpp
+++ w/intern/ghost/intern/GHOST_SystemX11.cpp
@@ -1181,7 +1181,10 @@ GHOST_SystemX11::processEvent(XEvent *xe)
 		default:
 		{
 #ifdef WITH_X11_XINPUT
-			if (xe->type == m_xtablet.MotionEvent) {
+			if (xe->type == m_xtablet.MotionEvent ||
+				xe->type == m_xtablet.MotionEventEraser ||
+				xe->type == m_xtablet.PressEvent ||
+				xe->type == m_xtablet.PressEventEraser) {
 				XDeviceMotionEvent *data = (XDeviceMotionEvent *)xe;
 				const unsigned char axis_first = data->first_axis;
 				const unsigned char axes_end = axis_first + data->axes_count;  /* after the last */
diff --git i/intern/ghost/intern/GHOST_SystemX11.h w/intern/ghost/intern/GHOST_SystemX11.h
index bc35b6c..378f07d 100644
--- i/intern/ghost/intern/GHOST_SystemX11.h
+++ w/intern/ghost/intern/GHOST_SystemX11.h
@@ -286,6 +286,12 @@ public:
 		int MotionEvent;
 		int ProxInEvent;
 		int ProxOutEvent;
+		int PressEvent;
+
+		int MotionEventEraser;
+		int ProxInEventEraser;
+		int ProxOutEventEraser;
+		int PressEventEraser;
 
 		int PressureLevels;
 		int XtiltLevels, YtiltLevels;
diff --git i/intern/ghost/intern/GHOST_WindowX11.cpp w/intern/ghost/intern/GHOST_WindowX11.cpp
index 125ec26..0b3df19 100644
--- i/intern/ghost/intern/GHOST_WindowX11.cpp
+++ w/intern/ghost/intern/GHOST_WindowX11.cpp
@@ -577,7 +577,7 @@ void GHOST_WindowX11::initXInputDevices()
 	if (version && (version != (XExtensionVersion *)NoSuchExtension)) {
 		if (version->present) {
 			GHOST_SystemX11::GHOST_TabletX11 &xtablet = m_system->GetXTablet();
-			XEventClass xevents[10], ev;
+			XEventClass xevents[8], ev;
 			int dcount = 0;
 
 			/* With modern XInput (xlib 1.6.2 at least and/or evdev 2.9.0) and some 'no-name' tablets
@@ -588,7 +588,7 @@ void GHOST_WindowX11::initXInputDevices()
 			if (xtablet.StylusDevice) {
 				DeviceMotionNotify(xtablet.StylusDevice, xtablet.MotionEvent, ev);
 				if (ev) xevents[dcount++] = ev;
-				DeviceButton1Motion(xtablet.StylusDevice, xtablet.MotionEvent, ev);
+				DeviceButtonPress(xtablet.StylusDevice, xtablet.PressEvent, ev);
 				if (ev) xevents[dcount++] = ev;
 				ProximityIn(xtablet.StylusDevice, xtablet.ProxInEvent, ev);
 				if (ev) xevents[dcount++] = ev;
@@ -596,13 +596,13 @@ void GHOST_WindowX11::initXInputDevices()
 				if (ev) xevents[dcount++] = ev;
 			}
 			if (xtablet.EraserDevice) {
-				DeviceMotionNotify(xtablet.EraserDevice, xtablet.MotionEvent, ev);
+				DeviceMotionNotify(xtablet.EraserDevice, xtablet.MotionEventEraser, ev);
 				if (ev) xevents[dcount++] = ev;
-				DeviceButton1Motion(xtablet.EraserDevice, xtablet.MotionEvent, ev);
+				DeviceButtonPress(xtablet.EraserDevice, xtablet.PressEventEraser, ev);
 				if (ev) xevents[dcount++] = ev;
-				ProximityIn(xtablet.EraserDevice, xtablet.ProxInEvent, ev);
+				ProximityIn(xtablet.EraserDevice, xtablet.ProxInEventEraser, ev);
 				if (ev) xevents[dcount++] = ev;
-				ProximityOut(xtablet.EraserDevice, xtablet.ProxOutEvent, ev);
+				ProximityOut(xtablet.EraserDevice, xtablet.ProxOutEventEraser, ev);
 				if (ev) xevents[dcount++] = ev;
 			}

Hi, We had a similar problem here with Wacom tablets, I was able to make the pressure work. The problem is in GHOST_WindowX11, the events are overwritten by the X11's macros (DeviceMotionNotify), once for the sytus and secondly for the eraser case (line 587-607). Here's the patch: ``` diff --git i/intern/ghost/intern/GHOST_SystemX11.cpp w/intern/ghost/intern/GHOST_SystemX11.cpp index d4693e9..1a80efd 100644 --- i/intern/ghost/intern/GHOST_SystemX11.cpp +++ w/intern/ghost/intern/GHOST_SystemX11.cpp @@ -1181,7 +1181,10 @@ GHOST_SystemX11::processEvent(XEvent *xe) default: { #ifdef WITH_X11_XINPUT - if (xe->type == m_xtablet.MotionEvent) { + if (xe->type == m_xtablet.MotionEvent || + xe->type == m_xtablet.MotionEventEraser || + xe->type == m_xtablet.PressEvent || + xe->type == m_xtablet.PressEventEraser) { XDeviceMotionEvent *data = (XDeviceMotionEvent *)xe; const unsigned char axis_first = data->first_axis; const unsigned char axes_end = axis_first + data->axes_count; /* after the last */ diff --git i/intern/ghost/intern/GHOST_SystemX11.h w/intern/ghost/intern/GHOST_SystemX11.h index bc35b6c..378f07d 100644 --- i/intern/ghost/intern/GHOST_SystemX11.h +++ w/intern/ghost/intern/GHOST_SystemX11.h @@ -286,6 +286,12 @@ public: int MotionEvent; int ProxInEvent; int ProxOutEvent; + int PressEvent; + + int MotionEventEraser; + int ProxInEventEraser; + int ProxOutEventEraser; + int PressEventEraser; int PressureLevels; int XtiltLevels, YtiltLevels; diff --git i/intern/ghost/intern/GHOST_WindowX11.cpp w/intern/ghost/intern/GHOST_WindowX11.cpp index 125ec26..0b3df19 100644 --- i/intern/ghost/intern/GHOST_WindowX11.cpp +++ w/intern/ghost/intern/GHOST_WindowX11.cpp @@ -577,7 +577,7 @@ void GHOST_WindowX11::initXInputDevices() if (version && (version != (XExtensionVersion *)NoSuchExtension)) { if (version->present) { GHOST_SystemX11::GHOST_TabletX11 &xtablet = m_system->GetXTablet(); - XEventClass xevents[10], ev; + XEventClass xevents[8], ev; int dcount = 0; /* With modern XInput (xlib 1.6.2 at least and/or evdev 2.9.0) and some 'no-name' tablets @@ -588,7 +588,7 @@ void GHOST_WindowX11::initXInputDevices() if (xtablet.StylusDevice) { DeviceMotionNotify(xtablet.StylusDevice, xtablet.MotionEvent, ev); if (ev) xevents[dcount++] = ev; - DeviceButton1Motion(xtablet.StylusDevice, xtablet.MotionEvent, ev); + DeviceButtonPress(xtablet.StylusDevice, xtablet.PressEvent, ev); if (ev) xevents[dcount++] = ev; ProximityIn(xtablet.StylusDevice, xtablet.ProxInEvent, ev); if (ev) xevents[dcount++] = ev; @@ -596,13 +596,13 @@ void GHOST_WindowX11::initXInputDevices() if (ev) xevents[dcount++] = ev; } if (xtablet.EraserDevice) { - DeviceMotionNotify(xtablet.EraserDevice, xtablet.MotionEvent, ev); + DeviceMotionNotify(xtablet.EraserDevice, xtablet.MotionEventEraser, ev); if (ev) xevents[dcount++] = ev; - DeviceButton1Motion(xtablet.EraserDevice, xtablet.MotionEvent, ev); + DeviceButtonPress(xtablet.EraserDevice, xtablet.PressEventEraser, ev); if (ev) xevents[dcount++] = ev; - ProximityIn(xtablet.EraserDevice, xtablet.ProxInEvent, ev); + ProximityIn(xtablet.EraserDevice, xtablet.ProxInEventEraser, ev); if (ev) xevents[dcount++] = ev; - ProximityOut(xtablet.EraserDevice, xtablet.ProxOutEvent, ev); + ProximityOut(xtablet.EraserDevice, xtablet.ProxOutEventEraser, ev); if (ev) xevents[dcount++] = ev; } ```

Bastien Montagne commented

2015-02-10 17:22:15 +01:00

Grrr… new x11 seems picky here.

Thanks for the patch, have a brand new wacom tablet, so will check (and hopefully apply!) soon. :)

Grrr… new x11 seems picky here. Thanks for the patch, have a brand new wacom tablet, so will check (and hopefully apply!) soon. :)

Cédric PAILLE commented

2015-02-10 17:32:19 +01:00

:)
Yes, would be interesting to know if it fixes for non-wacom tablets too...

:) Yes, would be interesting to know if it fixes for non-wacom tablets too...

Bastien Montagne commented

2015-02-13 11:06:46 +01:00

Applied, thanks again for the patch! :D

Cédric PAILLE commented

2015-02-13 11:10:05 +01:00

You're welcome !

Glad to hear it's working

You're welcome ! Glad to hear it's working

Storm commented

2015-03-05 17:08:36 +01:00

Changed status from 'Resolved' to: 'Open'

Storm reopened this issue

2015-03-05 17:08:36 +01:00

Storm commented

2015-03-05 17:08:36 +01:00

Added subscriber: @Storm-14

Storm commented

2015-03-05 17:08:36 +01:00

I'm still experiencing this issue as of today, with the latest Arch Linux package:
https://www.archlinux.org/packages/community/x86_64/blender/

My tablet is a Genius i608x, using udev drivers. Pressure works in Krita (painting program).

system-info.txt

I'm still experiencing this issue as of today, with the latest Arch Linux package: https://www.archlinux.org/packages/community/x86_64/blender/ My tablet is a Genius i608x, using udev drivers. Pressure works in Krita (painting program). [system-info.txt](https://archive.blender.org/developer/F147439/system-info.txt)

Bastien Montagne commented

2015-03-05 17:14:10 +01:00

Changed status from 'Open' to: 'Resolved'

Bastien Montagne closed this issue

2015-03-05 17:14:10 +01:00

Bastien Montagne self-assigned this 2015-03-05 17:14:10 +01:00

Bastien Montagne commented

2015-03-05 17:14:10 +01:00

Please do not reopen bugs yourself, this is manager task. If you had checked carefully, you would have seen that Arch package is 31/01, while last commit related to this report in Blender is from two weeks later (13/02)…

Furthermore, please always test with latest official version (from our buildbot), non-official builds such as distribution packages are not accepted in a bug report.

Please **do not** reopen bugs yourself, this is manager task. If you had checked carefully, you would have seen that Arch package is 31/01, while last commit related to this report in Blender is from two weeks later (13/02)… Furthermore, please **always** test with **latest official** version (from [our buildbot](https://builder.blender.org/download)), non-official builds such as distribution packages are not accepted in a bug report.

Storm commented

2015-03-06 18:33:24 +01:00

My apologies. I thought it's OK to change status, since the system allows me to do it...

This issue was said to be fixed on 27/01 (in a forum thread about the issue, linking to the 27/01 commit above: https://developer.blender.org/T43367#284437 ) which is 4 days before the Arch package build date so I expected it should already be in there.

I'm going to contact the Arch package maintainer then.

My apologies. I thought it's OK to change status, since the system allows me to do it... This issue was said to be fixed on 27/01 (in a forum thread about the issue, linking to the 27/01 commit above: https://developer.blender.org/T43367#284437 ) which is 4 days before the Arch package build date so I expected it should already be in there. I'm going to contact the Arch package maintainer then.

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Non-wacom tablets broken on Blender in linux? #43367

Issue

Investigations

pen is hovering tablet...

pen goes down

pen is drawing

pen goes up

pen is hovering tablet again...