Pointer glide patch for Input/synaptics

[Peter Hutterer]

On Thu, Jan 22, 2009 at 08:28:21AM -0800, Dylan McCall wrote:
> I'm just wondering what people think of the little "pointer glide" thing
> I submitted. Here would be a better place for discussion than on
> bugzilla, if anyone is interested :)

IMHO, for new features the list is a better place than bugzilla, so I do
encourage you that you send out the patch to the list, ideally as git
formatted patch.

[btw, your bug didn't get ignored, just ETIME and whatnot.]

> With a touchpad, everything is an indirect type of motion without any
> physical feedback (which is perhaps why it has been, until now, widely
> despised). The touchpad doesn't move; it just acts as a window through
> which the pointer is nudged. At the moment the pointer is a difficult
> object to nudge. A bit like pushing it through syrupy goo. It just
> doesn't move unless the user PUSHES it at all times. It doesn't make as
> much sense and it doesn't feel like it applies to the real world, no
> matter what paper-like texture the manufacturer puts over the touchpad.
> (They should really be using a sticky goo texture if they want it to
> feel natural).
> 
> My idea is to give the pointer a more believable, and at the same time
> more comfortable presence when using the touchpad. Since the device
> itself doesn't provide any kind of feedback, we have to assume "the
> pointer" is fairly light, with a small amount of friction so it can be
> pushed easily. This way the user can interact more naturally. Silly, but
> I'm sure this can all be linked to some pseudo-scientific psychology
> babble.

These are a couple of strong statements that you haven't really backed up
other than with your personal opinions. Do you have any references that this
actually improves the behaviour, or that users actually use it?
Synaptics already suffers from feature-bloat, so additional features should
at least have some potential users.
 
> This is all achieved through ridiculously primitive physics, of course!
> I have the pointer continuing along its path when the finger is
> released, slowed down gradually by a set friction and capped with a
> maximum speed to avoid anything weird happening. The pointer glide
> behaviour only gets in the way if one is expecting it, and defaults to
> being turned off.

Can you explain what reasonable defaults one should use for the friction?
The default ones (I just applied the patch here) don't really make sense to
me. If anything, they make the touchpad harder to use as there's a high chance
that the pointer keeps moving after I have released over a button and I miss
the target.

Cheers,
  Peter