From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denis Oliver Kropp Subject: Re: DirectFB without FBDev Date: Wed, 28 May 2008 20:33:35 +0200 Message-ID: <483DA57F.6070602@directfb.org> References: <483D7344.6030503@directfb.org> <483D9453.1080700@directfb.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1K1QUH-0006y9-Cl for linux-fbdev-devel@lists.sourceforge.net; Wed, 28 May 2008 11:35:01 -0700 Received: from directfb.org ([212.227.87.76] helo=www.directfb.org) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1K1QUC-0002hz-Qa for linux-fbdev-devel@lists.sourceforge.net; Wed, 28 May 2008 11:35:01 -0700 In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: Geert Uytterhoeven Cc: linux-fbdev-devel@lists.sourceforge.net, directfb-users@directfb.org, directfb-dev@directfb.org Geert Uytterhoeven wrote: > On Wed, 28 May 2008, Denis Oliver Kropp wrote: >> Geert Uytterhoeven wrote: >>> On Wed, 28 May 2008, Denis Oliver Kropp wrote: >>>> One major bug at the moment is mode switching and pitch values being >>>> wrong. It's dumb to >>>> return the pitch of the variable mode settings in the fixed settings >>>> structure anyhow, but >>>> if you like to start with the above mentioned mission, that's where it >>>> could begin. >>> Do you care to tell us why this is dumb? >> Ok, the fixed information should not contain information that changes over >> time, >> otherwise it is not fixed, at least that's my understanding of "fixed". > > It's `fixed' not in the sense that it can never change, but that it > purely depends on the info in struct fb_var_screeninfo. I'd prefer an ioctl which has input and output fields in the accompanied struct, so that the resulting pitch is returned to the user space with the same system call. >>> The pitch depends on the video mode and the hardware requirements, >>> that's why it's in struct fb_fix_screeninfo. >> It would suffice to encode the pitch requirements independent from the video >> mode, >> i.e. just put the pixel or byte alignment into the fixed structure. > > What if the pitch requirements depend on the video mode? Haven't seen that, usually either pixels or bytes just needs to be a multiple of something. In these cases you could simply forbid/fail to choose the pitch and just return it in the variable structure. > There exists graphics hardware where fb_fix_screeninfo.type depends on > the video mode. Sure, type depends on the pixelformat :) -- Best regards, Denis Oliver Kropp .------------------------------------------. | DirectFB - Hardware accelerated graphics | | http://www.directfb.org/ | "------------------------------------------" ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/