Messages in this thread | | | Date | Wed, 14 Mar 2007 20:04:32 +0200 | From | Anssi Hannula <> | Subject | Re: FF layer restrictions [Was: [PATCH 1/1] Input: add sensable phantom driver] |
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Jiri Slaby wrote: > Dmitry Torokhov napsal(a): >> On 3/13/07, Jiri Slaby <jirislaby@gmail.com> wrote: >>> 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.
Interesting. What kind of device is that? i.e. what is the third direction value?
>>>> 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 > > I definitely agree. > >> rather add new set of 3D effects. > > I was thinking about having "raw" (e.g. FF_RAW) effect, which would be only > X "axes"/entries of u32, where X is about 10 for future use and simply > posting these values further to HW (maybe after clamping or driver specific > processing) from this array. This seems to be augmentation of FF_CONSTANT > but the fact, it doesn't compute forces from direction.
I don't like the idea of a driver-specific "raw" effect, I'd rather add real effect types.
> Also yet another one such as FF_VECTOR or FF_3D could be considered as one > posibility, but it's still the same -- to have no more than 3 entries to > pass forces... > >> Do we have any idea if there any users of FF out there? > > At least me :). I'm using it for wheel and joystick in modules for locally > developped multiplatform virtual reality system.
Wine and BZflag come to mind, though I think the support is quite limited in both.
-- Anssi Hannula
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