From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Echtler Subject: Re: Questions about Multi-touch Protocal Date: Tue, 05 Jan 2010 13:42:13 +0100 Message-ID: <1262695333.8529.8.camel@pancake> References: <4B42D998.4050303@samsung.com> <4B432BDB.3000103@euromail.se> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from static.88-198-47-201.clients.your-server.de ([88.198.47.201]:60167 "EHLO butterbrot.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751563Ab0AEMsa (ORCPT ); Tue, 5 Jan 2010 07:48:30 -0500 In-Reply-To: <4B432BDB.3000103@euromail.se> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Henrik Rydberg Cc: Joonyoung Shim , linux-input@vger.kernel.org, dmitry.torokhov@gmail.com, jkosina@suse.cz > The TOUCH and WIDTH parameters have a geometrical interpretation; imagine > looking through a window at someone gently holding a finger against the glass. > You will see two regions, one inner region consisting of the part of the finger > actually touching the glass, and one outer region formed by the perimeter of the > finger. The diameter of the inner region is the ABS_MT_TOUCH_MAJOR, the diameter > of the outer region is ABS_MT_WIDTH_MAJOR. Now imagine the person pressing the > finger harder against the glass. The inner region will increase, and in general, > the ratio ABS_MT_TOUCH_MAJOR / ABS_MT_WIDTH_MAJOR, which is always smaller than > unity, is related to the finger pressure. > In addition to the MAJOR parameters, the oval shape of the finger can be > described by adding the MINOR parameters, such that MAJOR and MINOR are the > major and minor axis of an ellipse. Finally, the orientation of the oval shape > can be describe with the ORIENTATION parameter. > Hope this explains it a bit further. Very interesting writeup, thanks a lot. Is there any currently any hardware which is available to end-users and does support these features? AFAIR most capacitive touchscreens don't have high enough resolution to actually detect, e.g., twisting. If there's a commercial option, I'd like to hear about it.. Florian -- 0666 - Filemode of the Beast