On 08/02/2010 06:26 PM, Dmitry Torokhov wrote: > On Mon, Aug 02, 2010 at 01:22:15PM +0200, Henrik Rydberg wrote: >> On 08/02/2010 01:12 PM, Éric Piel wrote: >> >>> Op 02-08-10 12:02, Henrik Rydberg schreef: >>>> On 08/02/2010 10:17 AM, Éric Piel wrote: >>>> >>>>> Op 01-08-10 15:57, Henrik Rydberg schreef: >>>>>> On 08/01/2010 01:28 PM, Éric Piel wrote: >>>>> : >>>>>>> I still think that for the very specific use case of scrolling when >>>>>>> pressing one finger and moving up and dow the other one, reporting the >>>>>>> average works better than the first finger. However, I guess this can be >>>>>>> considered just as a drawback of the ST protocol, and fixed in userspace >>>>>>> by using the MT protocol. >>>>>>> >>>>>>> What do you think? Does it look fine to you? Below is the code. >>>>>> >>>>>> >>>>>> I might have lost track of what problem needs to be solved. The current patch >>>>>> seems to implement tracking, but still does not solve the individual MT finger >>>>>> problem. And, it uses the same definition of ABS_X/Y as before. I was also under >>>>>> the impression that synaptics needs fixing, anyways. All of this taken together >>>>>> sadly suggests that this patch could just as well be reverted to the original >>>>>> one. Or? Alternatively, one could switch to the type B protocol, since no >>>>>> further tracking improvement is possible in userspace. The implementation is >>>>>> tidy and simple enough, I think. >>>>> Yes, you're right, the patch I've sent was still with the "average of >>>>> the 2 fingers", but I'm now willing to drop it. With the tracking, at >>>>> least we can keep sending info about a real finger and avoid jumps at >>>>> the transition 1->2, so reporting the first finger might have advantages >>>>> over reporting the average :-) The improvement for the test case can >>>>> just go to userspace. >>>>> >>>>> The tracking is still not so clever, so it's definitly not adapted to a >>>>> type B MT protocol (think transition 2->1). >>>> >>>> >>>> You need to add the tracking id and a couple of lines, but i do not see why the >>>> 2->1 transition would be treated any differently. The one-finger coordinate >>>> would be close to either position[0] or position[1], which would determine the >>>> tracking id to keep. Every time you add a finger you add a new tracking id. What >>>> is your planned support for three fingers? >>> Yes, yes, it's probably fairly easy to do some kind of tracking. But I >>> think that as long as the hardware does not provide such a thing, it's >>> better to do the minimum in kernel space, just enough to be meaningful, >>> and leave the rest to userspace. >> >> >> The implemented part could also be done in userspace. Going half-way just to >> circumvent buggy behavior in synaptics is really not a good idea. >> > > What synaptics you are talking about here? Userspace driver or the > in-kernel synaptics support? If the latter, then the device is not truly > multitouch device (latest versions of the hardware/firmware aside) as it > is capable of reportiong only one set of coordinates (X/Y) in addition > to number of fingers on the surface. > I was referring to the user-space driver. Henrik -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
