From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752218Ab2EHXsg (ORCPT ); Tue, 8 May 2012 19:48:36 -0400 Received: from leo.clearchain.com ([199.73.29.74]:25199 "EHLO mail.clearchain.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751149Ab2EHXse (ORCPT ); Tue, 8 May 2012 19:48:34 -0400 Date: Wed, 9 May 2012 09:52:19 +1000 From: Peter Hutterer To: Henrik Rydberg Cc: Benjamin Tissoires , Dmitry Torokhov , Jiri Kosina , chatty@enac.fr, chasedouglas@gmail.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] Input: MT - Include win8 support Message-ID: <20120508235219.GA4067@yabbi.redhat.com> References: <1336230499-1450-1-git-send-email-rydberg@euromail.se> <20120506182835.GA12221@polaris.bitmath.org> <20120508060221.GA15925@yabbi.bne.redhat.com> <20120508184052.GA23748@polaris.bitmath.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120508184052.GA23748@polaris.bitmath.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Greylist: Sender is SPF-compliant, not delayed by milter-greylist-4.0.1 (mail.clearchain.com [127.0.0.1]); Wed, 09 May 2012 09:18:33 +0930 (CST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 08, 2012 at 08:40:52PM +0200, Henrik Rydberg wrote: > > > to aid in the discussion, I have shared a drawing of the MT model > > > and the (supposed) win8 model. > > > > > > https://docs.google.com/document/d/1KKu7kqPOsvE9tCmWhdGnmO8tgmN0Cd-Mv_crVaCZueY/view > > > > having an asciiart version of this in Documentation/ would be quite useful, > > IMO > > Yep, that ought to be possible to arrange. > > > Insert a paragraph into the actual documentation. I think that's more > > helpful than tacking it on (if not quite as nice in a diff) > > > > "The orientation of the ellipse. The value should describe a signed quarter > > of a revolution clockwise around the touch center. The signed value range > > is arbitrary, but zero should be returned for a finger aligned along the Y > > axis of the surface, a negative value when finger is turned to the left, and > > a positive value when finger turned to the right. When completely aligned > > with the X axis, the range max should be returned. > > > > Touch ellipsis are symmetrical by default. For devices capable of true 360 > > degree orientation, the reported orientation must exceed the range max to > > indicate more than a quarter of a revolution. For an upside-down finger, > > range max * 2 should be returned. > > > > Orientation can be omitted if the touching object is circular, or if the > > information is not available in the kernel driver. Partial orientation > > support is possible if the device can distinguish between the two axis, but > > not (uniquely) any values in between. In such cases, the range of > > ABS_MT_ORIENTATION should be [0, 1] [4]." > > Looks good, will copy that in its entirety. :-) > > > Not a big fan of reporting values above absmin/absmax, tbh. It means we > > can't rely on the axis values and have to special-case it. Plus, there's no > > way to detect this before you actually get a value. > > True, and I am open to other suggestions. However, I think the > proposal integrates pretty well with the existing model and is likely > to produce reasonable results without userland modifications. > > > > Looking at the figure, it is clear that the MT model has two centers, > > > one for each ellipse. Thus, center is not discriminating > > > enough. Perhaps ABS_MT_OUTER_X/Y is more appropriate, then? > > > > ABS_MT_OUTER_CENTER > > I appreciate the suggestion, but along two-word combinations, > ABS_MT_OUTER_POSITION would integrate better with existing names. Both > seem awfully long, though. problem I see with "outer position" is that I'd associate it with the top/left position of whatever "outer" is, not with the center of said envelope. that's why I'd argue that "center" should be somewhere in the name. Cheers, Peter