Re: FF layer restrictions [Was: [PATCH 1/1] Input: add sensable phantom driver]

[johann deneux]

On 3/16/07, Pavel Machek <pavel@xxxxxx> wrote:
> Hi!
>
> > >Why did you remove all Cced people? Anyway I filtered
> > >some of them out
> > >
> > >johann deneux napsal(a):
> > >> You are right, the direction in ff_effect is meant to
> > >be an angle.
> > >> A dirty solution would be to use the 16 bits as two
> > >8-bits angles. Or
> > >
> > >That would be a problem as I need 3x 16bits.
> > >
> > >> maybe we should change the API. I don't think there
> > >are many
> > >> applications using force feedback yet, so maybe that
> > >should be ok?
> > >>
> > >> If we change the API, we should remove the assumption
> > >that a device has
> > >> at most two axes to render effects. We could for
> > >instance have a
> > >> magnitude argument for each axis which is capable of
> > >rendering effects.
> > >> That might be necessary even for more common gaming
> > >devices like racing
> > >> wheels: One can think pedals could also be capable of
> > >force feedback
> > >> some day, not just the steering wheel.
> > >
> > >I can do that, but in that case, I need to know how
> > >people (especially those
> > >input one) want me to do...
> > >
> >
> > Since we have no idea how many programs (if any) are
> > using force
> > feedback interface I would be wary of changing existing
> > effcets and
> > rather add new set of 3D effects.
> >
> > Do we have any idea if there any users of FF out there?
>
> Number of linux games is quite low, so...
>
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Games are not the only application type using FF. I got a few
enquiries from universities working on robotics project.
I think keeping backward compatibility is not a problem here. The
problem is to make an extension that does not duplicate the
capabilities of the existing API. We don't want to have two ways of
specifying the same effects.

--
Johann
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