STenyaK (Bruno González) napsal(a): > On 3/14/07, Dmitry Torokhov <[EMAIL PROTECTED]> 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, I need 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 may need more than 3 axis. no matter if torques or vector is passed -- depending on 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 Slaby faculty of informatics, masaryk university, brno, cz e-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" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
