From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Antonino A. Daplas" Subject: Re: fixing fbdev for various framebuffer configs Date: Fri, 29 Jul 2005 19:44:36 +0800 Message-ID: <42EA16A4.2050709@gmail.com> References: <9e473391050729035370d76cc5@mail.gmail.com> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 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.sourceforge.net with esmtp (Exim 4.30) id 1DyTIN-0001f1-0W for linux-fbdev-devel@lists.sourceforge.net; Fri, 29 Jul 2005 04:44:55 -0700 Received: from wproxy.gmail.com ([64.233.184.201]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1DyTIL-0004N8-N0 for linux-fbdev-devel@lists.sourceforge.net; Fri, 29 Jul 2005 04:44:55 -0700 Received: by wproxy.gmail.com with SMTP id i3so618241wra for ; Fri, 29 Jul 2005 04:44:42 -0700 (PDT) In-Reply-To: <9e473391050729035370d76cc5@mail.gmail.com> Sender: linux-fbdev-devel-admin@lists.sourceforge.net Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: linux-fbdev-devel@lists.sourceforge.net Cc: "Antonino A. Daplas" , Geert Uytterhoeven , James Simmons Jon Smirl wrote: > It has been determined that bits per pixel is insuffucient to > enumerate all the needed fbconfigs. Here are the possible fgconfigs > from the OpenGL headers: > > total bits > 8 GL_R3_G3_B2 > 8 GL_RGBA2 > 12 GL_RGB4 > 15 GL_RGB5 > 16 GL_R5_G6_B5 > 16 GL_RGBA4 > 16 GL_RGB5_A1 > 24 GL_RGB8 > 30 GL_RGB10 > 32 GL_RGBA8 > 32 GL_RGB10_A2 > 36 GL_RGB12 > 48 GL_RGB16 > 48 GL_RGBA12 > 48 GL_FLOAT_RGB16 > 64 GL_RGBA16 > 64 GL_FLOAT_RGBA16 > 96 GL_FLOAT_RGB32 > 128 GL_FLOAT_RGBA32 > > We need to be able to set any of these through the fbdev interface. We > also need to allow for possible future expansion. To set for example, RGBA16, set {transp|green|red|blue}.len to 16, the offsets to 0, 16, 32, 48, and bits_per_pixel to 64. Then let the driver sort it out. I don't know what we can do about the FLOAT formats... > > Ideas on how to adjust the fbdev interface? Well, no need to adjust the interface. But it is limited though to 16 bits per channel. Redefining them to 32 will break a lot of apps. > > What is the effect of alpha bits on the scanout buffer, do they do anything? > I think if there is another layer such as an overlay, the alpha bits can control the transparency between the framebuffer and the overlay. If only the framebuffer is active, I don't believe it has any effects. Tony ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf