From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?=C9ric_Piel?= Subject: Re: [PATCH 7/7] elantech: average the two coordinates when 2 fingers Date: Mon, 02 Aug 2010 14:46:40 +0200 Message-ID: <4C56BE30.2070807@tudelft.nl> References: <4C1FD2B0.1080504@tudelft.nl> <4C1FD454.4050807@tudelft.nl> <20100721033655.GA9070@core.coreip.homeip.net> <4C532009.4020103@tudelft.nl> <4C533DC3.9070001@euromail.se> <4C54ABFE.8050106@tudelft.nl> <4C554058.6080203@euromail.se> <4C555A44.5050505@tudelft.nl> <4C557D3A.3050501@euromail.se> <4C567F27.7070900@tudelft.nl> <4C5697C4.1020801@euromail.se> <4C56A81E.3040703@tudelft.nl> <4C56AA67.8000902@euromail.se> <4C56AD12.1080106@tudelft.nl> <4C56B00B.50204@euromail.se> <4C56B686.60606@tudelft.nl> <4C56BA13.3030104@euromail.se> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mailservice.tudelft.nl ([130.161.131.5]:53488 "EHLO mailservice.tudelft.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751852Ab0HBMqm (ORCPT ); Mon, 2 Aug 2010 08:46:42 -0400 In-Reply-To: <4C56BA13.3030104@euromail.se> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Henrik Rydberg Cc: Chris Bagwell , Dmitry Torokhov , "linux-input@vger.kernel.org" , Florian Ragwitz Op 02-08-10 14:29, Henrik Rydberg schreef: > On 08/02/2010 02:13 PM, =C9ric Piel wrote: : >>> The above tells me that the MT situation did not improve much, and = that the >>> major improvement is to paper over the synaptics problem. >> For me it has changed because my argument was "with two finger we re= port >> crap anyway, so let's report the average". With the tracking, we >> actually (often) report the real position of the fingers, so this >> argument is not valid anymore. Now we can happily say we conform to = the >> official protocols: ST (which apparently requires to always reports = an >> actual position), and MT-A. >=20 >=20 > It does not comply with MT-A as long as two semi-random corners of a = rectangle > are reported. =46air enough. Without the tracking patch it complied with MT-A 50% of = the time, with it it's 75% of the time... I guess it's still not called "complying" ;-) >>> The argument to go forward implementing protocol B is that the curr= ent patch >>> actually does proper two-finger tracking to the extent that it is p= ossible. >>> Since mtdev cannot improve the fact that this device does not follo= wing fingers >>> but corners, it makes sense to treat this device specially, and imp= lement the >>> extra lines in the kernel to make it as good as it can be. Alternat= ively, one >>> can give up the idea of using MT in this driver altogether, and jus= t implement >>> the mean position ABS_X/Y, old-style. >> Do you think that if we implement full tracking in kernel, we can do >> _better_ than the small tracking + mtdev? I don't think so (but, hey= , >> I've been tinkering with multitouch for something like 20h in my lif= e, >> so I might have missed something ;-) ). If you have in mind a better >> performing algorithm, then let me know, and I'll happily implement i= t in >> kernel :-) >=20 >=20 > We can do better in the sense that since the device cannot comply wit= h MT-A, we > can do as close as possible to MT-B with less cpu usage. But frankly,= the best > solution at this stage seems to be to drop MT handling altogether, si= nce there > does not seem to be any plan to use it. Ah, this alternative solution is a bit boring ;-) In addition it's not compatible with my own master plan to eventually have the "pinch to zoom" and "rotate to rotate" gestures work on my laptop, like in Window= s ;-) So, let's agree on just the two patches I'm going to send to support "better than nothing" MT-protocol for now. When, later, someone has better ideas, he can send patches to improve MT-protocol support/compliance. Fine? Eric -- 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