`STenyaK (Bruno González) napsal(a):> On 3/14/07, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:>> > I have a question: if the force is to be 3D, why only 3 possible>> values?>> > What would they be, 3 torques or 3 forces? In the case of car sims (ff>> > steering wheels), only one axis of torque is usually used (except>> for 6 dof>> > platforms, as mentioned).>> >>>>> I wonder if we could somehow extend or augment FF envelope se we could>> specify a plane for the effect.. Then a vector could be represented by>> a sum 3 constant effects in 3 separate planes and we could also use>> spring and other effects as well.> > Ideally, afaik we should use:> -3 values for translation force (linear force): x,y,z components of> the force vector.> -4 values for rotation force (torque): x,y,z,w components of the> quaternion. You can also use euler angles (and i think there are> another one or two notations), which is just 3 values, but i'm not> sure it will be a correct decision (due to the gimbal lock problem,> which may or may not be present in ff devices, dunno).So, the resolution is? Since I want no longer have out-of-kernel driver, Ineed to know how to implement the phantom driver -- merge it `as is', i.e.control through mmio or rewrite ff layer somehow, and in that case how?There seem to be only few possibilities:- new 3D effect, which will be problematic in any other future use, that mayneed more than 3 axis. no matter if torques or vector is passed -- dependingon device and programmer (as I need to compute torques from forces in FP).Maybe struct with 2x 3 axis is OK- "raw" effect, which may contain more axis, but this is ugly in Anssi's eyes- something else? (did I forget something)thanks,-- http://www.fi.muni.cz/~xslaby/            Jiri Slabyfaculty of informatics, masaryk university, brno, cze-mail: jirislaby gmail com, gpg pubkey fingerprint:B674 9967 0407 CE62 ACC8  22A0 32CC 55C3 39D4 7A7E-To unsubscribe from this list: send the line "unsubscribe linux-kernel" inthe body of a message to majordomo@vger.kernel.orgMore majordomo info at  http://vger.kernel.org/majordomo-info.htmlPlease read the FAQ at  http://www.tux.org/lkml/`