From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934140AbXC0Sgo (ORCPT ); Tue, 27 Mar 2007 14:36:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934148AbXC0Sgo (ORCPT ); Tue, 27 Mar 2007 14:36:44 -0400 Received: from ug-out-1314.google.com ([66.249.92.170]:50771 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934140AbXC0Sgm (ORCPT ); Tue, 27 Mar 2007 14:36:42 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=gHcieZzMR4qGiKbjBZPHGUlYoaRApqKnfGkqLBbDy3c45vt9Hoj7lK3trZHxcb8pHlA4Vn0r/SbFYYqX+xscBBqPGzFZk9FDyP0Vo7yUassxqR4GRB2qQ3+xI6FUiUmbWt5tFdT4fZlElSuBS1B7mS2WqzcHXhpRLcWwgQUyoKE= Message-ID: <38b3b7c0703271136s799114fcndfaa6de8db52fc70@mail.gmail.com> Date: Tue, 27 Mar 2007 20:36:38 +0200 From: "johann deneux" To: "Jiri Slaby" Subject: Re: FF layer restrictions [Was: [PATCH 1/1] Input: add sensable phantom driver] Cc: "Dmitry Torokhov" , "=?ISO-8859-1?Q?\"STenyaK_(Bruno_Gonz=E1lez)\"?=" , "Anssi Hannula" , "Linux kernel mailing list" , linux-input@atrey.karlin.mff.cuni.cz In-Reply-To: <46090BF2.2000105@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <2460126662758025813@fi.muni.cz> <46018FB8.1080601@gmail.com> <38b3b7c0703211503s3a8ee177v5b149cfd5975de8c@mail.gmail.com> <200703221150.12403.dtor@insightbb.com> <46090BF2.2000105@gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 3/27/07, Jiri Slaby wrote: > Dmitry Torokhov napsal(a): > > On Wednesday 21 March 2007 18:03, johann deneux wrote: > >> On 3/21/07, Jiri Slaby wrote: > >>> Dmitry Torokhov napsal(a): > >>>> On 3/21/07, johann deneux wrote: > >>>>> I would suggest adding a new effect type (3d effect) and extending the > >>>>> union in struct ff_effect. > >>>>> Let me know if I'm too vague, I already suggested that solution but > >>>>> got no answer. I wonder if my mail got lost, nobody understood what I > >>>>> said, or if it's just a plain bad idea. > >>>>> > >>>> My concern with a new 3D effect is that it will be a very "simple" > >>>> effect with only constant force apllied. That might be enough for > >>>> phantom but may not be sufficient for future devices. If we add > >>>> ability to specify a "plane" for an effect we will be able to add > >>>> envelopes on top of more complex effects and get desired combined > >>>> effcet. > >>> I didn't get this too much, because I don't understand the FF layer well so > >>> far. How is this going to work? Let's say, we have 3 torque values computed > >>> in US, and this structure: > >>> > >>> struct ff_effect { > >>> __u16 direction; > >>> struct ff_trigger trigger; > >>> struct ff_replay replay; > >>> > >>> struct ff_constant_effect { > >>> __s16 level; > >>> struct ff_envelope { > >>> __u16 attack_length; > >>> __u16 attack_level; > >>> __u16 fade_length; > >>> __u16 fade_level; > >>> }; > >>> }; > >>> }; > >>> > >>> and need to pass the three 16bits torques into s16 ioaddr[0..2]. How? > >>> > >> Stupid question, > > Sorry to be out for so long, maybe I'm stupid idiot, that understands > nothing, but: No, it's not you, there are still things that are unclear. For instance I think Dmitry intended to combine several planes, which I don't understand. What we want is to specify a 3d vector, which can be done using two angles and a magnitude. One angle and the magnitude we already have in ff_effect, so all we need is an additional angle, which can be specified using a new ioctl. I originally thought it could be done without a new ioctl, just by extending ff_struct, but that won't work. > > >> I have forgotten the details of ioctl: Wouldn't the > >> following work? > > No, at least, as far as I understand this. I have computed _torques_, not > forces vector (this was misleading info in my first post), the question is > "how can I pass torques through plane and direction entries into KS?". Torques and forces are both represented as 3d vectors. Are we misunderstanding eachother maybe? By "vector" I mean a triplet of numbers, when you say "torques" and "forces vector", do you mean that each effect is composed of a bunch of torques? -- Johann