Re: [Linuxwacom-discuss] Wacom pen lagging when editing images

[Favux ... <fav...@gm...>]

On Wed, Jul 28, 2010 at 10:38 AM, Alexia Death <ale...@gm...> wrote:
> On Wednesday, July 28, 2010 16:46:46 Ashley Weaver wrote:
>> We’re having trouble with the pen lagging, and image display lag on the
>> wacom when using the editing features in an imaging program (Slicer 3D).
>> We are noticing this lag only when working on the wacom and when using a
>> regular monitor there is no lag.
> Monitor is not really a factor. Does it lag when you use a mouse? Have you
> tried a regular pen tablet?
>
>> There is also a decrease in the lagging
>> if the editing is done on a smaller portion of the wacom screen and not in
>> full screen mode so it appears to be related to the amount of information
>> processed. Is anyone else having similar issues or know a way to correct
>> this delay?   Wacom = 21UX, Machine = 64-bit linux running Red Hat.
>> Thanks!
> I am willing to bet this is a software issue. Ive encountered it in GIMP
> development. If your application uses event driven rendering, the events just
> overwhelm the CPU with screen refreshing, and yes, working in a smaller window
> would ease the load because it limits the area to be re-rendered, Tablets are
> so exact that theres many more events than would actually cause a perceptible
> change on screen and if an application still tries to refresh at each event,
> you get a huge lag. There are several issues in GIMP related to this very same
> problem and its still not completely solved but we are working on it...
>
> -- Alexia
>

Hi Alexia,

I've been meaning to ask you about this for a while.  Several of us
are noticing pronounced lag in Gimp with the stylus.  So it's a known
issue due to refresh and an underpowered CPU?  That makes sense, my
desktop CPU is old.  I'll have to see if that's true of the others.

HI Ashley,

The only thing I've found that helps is to change the RawSample rate.
Going from the default 4 to 20 helps minimize it some.  Although 30 to
35 is better the stylus then gets too jumpy outside the drawing area
for other things.

xsetwacom set "Wacom Cintiq 21UX2 stylus" RawSample "4"  # default is 4, 1-100

Anything else we can try Alexia?

Favux