[Interest] Slow pointer follow in Qt 5.2.2 (git) on freescale i.MX6 with tslib

[Stefano Cordibella]

Thank you for reporting your experience Jacob!

My problem is that I am forced to use an ltib environment for cross 
compiling, so it isn't so simple to compile the required libraries to 
support X11 backend...

Btw I see that using eglfs in an application that don't use QML (the Qt 
fingerpaint example), the pointer follow the finger at higher speed, as 
it should happen...
IMHO I think that the problem is bound to the new qml engine or in the 
interaction with the tslib plugin... But I don't know the library 
internals, so I cannot find any solution right now.

Stefano.


On 03/06/2014 10:45 AM, Jacob Kroon wrote:
> On Thu, Mar 6, 2014 at 10:20 AM, Stefano Cordibella 
> <stefano.cordibella at edalab.it <mailto:stefano.cordibella at edalab.it>> 
> wrote:
>
>     Thank you Jacob for your suggestion,
>         for this application the choice of using eglfs is not under my
>     direct control, in addition to this I suppose that the use of X11
>     can degrade the performance of the application (the target is a
>     imx6 Single...).
>
>     Did you noticed a decrease in performance moving from eglfs to X11?
>     Which imx6 did you used? Single Dual or Quad?
>
>
> It's just been some very rude basic testing, running a custom QML 
> application on Wandboard Solo and Wandboard Quad.
> I can't say I've seen any particular overhead in performance in 
> comparing X11/eglfs, but eglfs should in theory use less resources as 
> I see it.
> As a humble Qt5 user I'm simply suspecting that the eglfs backend has 
> seen less use, and is not as mature as the X11 backend yet.
>
>
>     Stefano.
>
>
>     On 03/06/2014 10:05 AM, Jacob Kroon wrote:
>>     Hi Stefano,
>>
>>     On Thu, Mar 6, 2014 at 9:22 AM, Stefano Cordibella
>>     <stefano.cordibella at edalab.it
>>     <mailto:stefano.cordibella at edalab.it>> wrote:
>>
>>         Hi Jacob,
>>             right, I did not specify that I use eglfs.
>>
>>
>>     I can just talk from my own personal experience in using
>>     Qt5+iMX6. In 5.1.1, eglfs had a hard time tracking the mouse
>>     pointer, 5.2.0 improved things a lot. But best experience sofar
>>     has been in using the X11 backend instead of eglfs.
>>
>>         Stefano.
>>
>>
>>         On 03/06/2014 08:53 AM, Jacob Kroon wrote:
>>>         Hi Stefano,
>>>
>>>         On Thu, Mar 6, 2014 at 8:47 AM, Stefano Cordibella
>>>         <stefano.cordibella at edalab.it
>>>         <mailto:stefano.cordibella at edalab.it>> wrote:
>>>
>>>             Hi list,
>>>                 using qt 5.2.2 (release branch from git, but I
>>>             noticed the same issue with 5.2.1) on I.MX6 it is
>>>             impossible to flick on qml elements, because the pointer
>>>             does not "follow" the finger on touchscreen...
>>>
>>>             The strange issue is that with non-qml application
>>>             (fingerpaint example) or using tslib test application
>>>             (ts_test) on device the cursor follow the finger at
>>>             higher speed.
>>>             Is this a libqtslibplugin.so or a qml issue?
>>>             I generated the plugin without any option, only qmake,
>>>             make and make install...
>>>
>>>             I am using tslib library because my touchscreen does not
>>>             support evdev (it is resistive?); I mean, trying to use
>>>             EvdevTouch does not work at all, using EvdevMouse I see
>>>             the pointer moving on screen, but the click doesn't work...
>>>
>>>             Any suggestion will be appreciated...
>>>
>>>         Which qpa backend are you using, xcb, wayland or eglfs ?
>>
>>
>>         -- 
>>         *Stefano Cordibella*
>>         EDALab s.r.l. - Networked Embedded Systems
>>
>>         Strada Le Grazie, 15 - 37134 Verona - Italy
>>         email : stefano.cordibella at edalab.it
>>         <mailto:stefano.cordibella at edalab.it>
>>         skype : stefano.cordibella
>>         tel. : +39 045 802 70 85 <tel:%2B39%20045%20802%2070%2085>
>>         web : www.edalab.it <http://www.edalab.it>
>>
>>
>>
>>
>>     -- 
>>       -- Jacob
>
>
>     -- 
>     *Stefano Cordibella*
>     EDALab s.r.l. - Networked Embedded Systems
>
>     Strada Le Grazie, 15 - 37134 Verona - Italy
>     email : stefano.cordibella at edalab.it
>     <mailto:stefano.cordibella at edalab.it>
>     skype : stefano.cordibella
>     tel. : +39 045 802 70 85 <tel:%2B39%20045%20802%2070%2085>
>     web : www.edalab.it <http://www.edalab.it>
>
>
>
>
> -- 
>   -- Jacob


-- 
*Stefano Cordibella*
EDALab s.r.l. - Networked Embedded Systems

Strada Le Grazie, 15 - 37134 Verona - Italy
email : stefano.cordibella at edalab.it
skype : stefano.cordibella
tel. : +39 045 802 70 85
web : www.edalab.it
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