From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trilok Soni Subject: Re: input: mt: Software finger tracking in the kernel? Date: Sun, 21 Mar 2010 00:57:20 +0530 Message-ID: <5d5443651003201227w27314533w6be3cdd8fb9bf5aa@mail.gmail.com> References: <4BA358DB.20708@enmesh.se> <167e8a331003192151o593809bbhcda68e284185dd4a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-qy0-f179.google.com ([209.85.221.179]:52449 "EHLO mail-qy0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751457Ab0CTT1W convert rfc822-to-8bit (ORCPT ); Sat, 20 Mar 2010 15:27:22 -0400 In-Reply-To: <167e8a331003192151o593809bbhcda68e284185dd4a@mail.gmail.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Ping Cheng Cc: Henrik Rydberg , Dmitry Torokhov , linux-input , "linux-kernel@vger.kernel.org" Hi Ping, On Sat, Mar 20, 2010 at 10:21 AM, Ping Cheng wrot= e: > On Fri, Mar 19, 2010 at 3:58 AM, Henrik Rydberg w= rote: >> Hi Dmitry, >> >> there is an ongoing discussion about adding multitouch to X >> (http://lists.x.org/archives/xorg-devel/2010-March/006206.html), whi= ch is >> beginning to take on more solid form. >> >> One of the suggestions emerging from that discussion is to add the s= oftware >> finger tracking to the kernel. Back in summer 2009 when I thought ab= out this, I >> disregarded it as being too experimental. I have since then reconsid= ered, >> starting to think it really is the right place. >> >> The MT protocol allows applications to take advantage of multi-conta= ct hardware, >> but leaves the problems of finger tracking and filtering to the user= =2E 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 resid= es in the >> kernel. Because of this, the finger matching and filtering would nat= urally >> 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_. =A0I'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 o= r > off. =A0If you plan to use a constant for the filtering method, pleas= e > 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. We have ABS_MT_PRESSURE added recently. I hope you are asking the same. --=20 ---Trilok Soni http://triloksoni.wordpress.com http://www.linkedin.com/in/triloksoni -- To unsubscribe from this list: send the line "unsubscribe linux-input" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html