On Fri, Mar 19, 2010 at 3:58 AM, Henrik Rydberg <rydberg@xxxxxxxxx> wrote: > Hi Dmitry, > > there is an ongoing discussion about adding multitouch to X > (http://lists.x.org/archives/xorg-devel/2010-March/006206.html), which is > beginning to take on more solid form. > > One of the suggestions emerging from that discussion is to add the software > finger tracking to the kernel. Back in summer 2009 when I thought about this, I > disregarded it as being too experimental. I have since then reconsidered, > starting to think it really is the right place. > > The MT protocol allows applications to take advantage of multi-contact hardware, > but leaves the problems of finger tracking and filtering to the user. Arguably, > no application can make good use of MT without these, so the problem is pushed > forward, in this case to evdev or equivalent. > > The knowledge of signal-to-noise ratios and prior input states resides in the > kernel. Because of this, the finger matching and filtering would naturally > reside within the kernel. > > So, if there were to appear patches to include matching in the input core, would > you consider them? :-) I support the idea to add a tracking ID and a filter to _MT_. I'd also like to make the filtering method more "device driver developer" friendly, i.e., give the developer the option to turn the filter on or off. If you plan to use a constant for the filtering method, please allow the developer to choose that constant too. Another attribute associated with _MT_ is the pressure/capacity. Report this value would offer more room for MT-aware application to add new features. Ping -- 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
