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. > Concerning 3 fingers (and more), the hardware reports only one set of > coordinates, the lower ones. So in this case, tracking is definitely not > possible. Ok. 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
