pointer (touchpad) aceleration and threshold too low in 11.3.* builds
Eduardo H. Silva
hoboprimate at gmail.com
Thu May 17 22:40:52 EDT 2012
2012/5/17 Paul Fox <pgf at laptop.org>:
> eduardo h. silva wrote:
> > 2012/5/17 Paul Fox <pgf at laptop.org>:
> > > eduardo h. silva wrote:
> > > > xset q tells that in 11.3.1, the pointer is configured with the values:
> > > >
> > > > acceleration 7/4 threshold: 1
> > > >
> > > > This takes 2, 3 and sometimes 4 swipes to move across the screen. It's
> > > > quite a difference with a typical touchpad on bigger laptops, and
> > > > although the experience can't be duplicated because we can't expect
> > > > kids to be already highly trained with a touchpad, I think it could be
> > > > improved.
> > > >
> > > > I think the balance is to have a larger threshold, so that slow
> > > > movements are allways acurate, and a higher acceleration, so that
> > > > movements across the screen are sufficiently fast (very important in
> > > > Sugar to access the frame for example). Managing to drop down the
> > > > amount of swipes needed to move across the screen (like 2 swipes)
> > > > would be excellent and more in par with the older pre 11.3.* behavior.
> > >
> > > so you think it was better, previously?
> > >
> > > i wonder what has changed. those xset values were chosen specifically
> > > to be appropriate for the original ALPS touchpad on XO-1. it's
> > > entirely possible, now that we're two laptops and at least as many
> > > touchpads beyond that, those numbers are incorrect.
> > I meant to compare between the setting of the builds back in 2008 and
> > 2011 when I began using the XO after a hiatus of years.
> > I found a discussion started about the change from "acceleration 7/4
> > threshold: 1" to "acceleration 7/4 threshold: 0)
> > (http://lists.laptop.org/pipermail/devel/2010-January/027245.html ). A
> > few messages later, it's shown in xset man page:
> > "If the `threshold' parameter is provided and 0, the
> > `acceleration' parameter will be used in the exponent of a
> > more natural and continous formula, giving precise control
> > for slow motion but big reach for fast motion, and a
> > progresive transition for motions in between. Recommended
> > `acceleration' value in this case is 3/2 to 2, but not
> > limited to that range "
> > Which is exactly what I was looking for. A bit later, Richard A. Smith tells:
> > "2 of the apps that our deployments spend a lot of time in are scratch
> > and etoys. Both of these are not completely sugarized apps and thus
> > some of the UI elements on the 200 dpi screen are quite small and hard
> > to use with a fast accel." Though I don't know if he used higher
> > acceleration values, or with threshold set to 0.
> > So the thread ends with:
> > "Find someone with kids and figure out whats the best settings for them."
> > Next time I am with my nephews I'll be sure to do this, but I already
> > find threshold 0 a lot better. Perhaps the problem Richard was having
> > could be solved with a lower acceleration, like 3/2, but still with
> > threshold 0.
> i'm sure you're right, and i think we had consensus around that
> several years ago. it's my belief (after skimming old mail) that the
> very earliest X servers shipped on XO-1 a) did treat a threshold of 0
> as special, but b) did not do it correctly. so using '1' at that time
> was deliberate. but after a time we (i, certainly) agreed that we
> should be using 0.
> we also had a discussion about lowering the 7/4 -- at the time i thought
> 3/2 was too slow, and suggested 165/100, but i suspect that that's
> splitting hairs. (i.e. 1.5 vs. 1.65).
> after verifying, we should at least fix the '0' threshold as a bug, in
If it's to be fixed, can't it be changed for the upcoming 11.3.1 as well?
More information about the Devel