From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Alexander E. Patrakov" Subject: directcolor colormap question Date: Mon, 19 Sep 2005 20:00:47 +0600 Message-ID: <432EC48F.40804@ums.usu.ru> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1EHMHG-0005Hm-Ev for linux-fbdev-devel@lists.sourceforge.net; Mon, 19 Sep 2005 07:05:50 -0700 Received: from relay4.usu.ru ([194.226.235.39]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1EHMHC-0004uq-M5 for linux-fbdev-devel@lists.sourceforge.net; Mon, 19 Sep 2005 07:05:50 -0700 Received: from relay4.usu.ru (localhost [127.0.0.1]) by relay4.usu.ru (PostSystem) with ESMTP id 1055316A66 for ; Mon, 19 Sep 2005 20:05:35 +0600 (YEKST) Received: from usu2.usu.ru (usu2.usu.ru [194.226.237.16]) by relay4.usu.ru (PostSystem) with ESMTP id 9896616A66 for ; Mon, 19 Sep 2005 20:05:34 +0600 (YEKST) Received: from localhost.usu2.usu.ru (localhost.usu2.usu.ru [127.0.0.1]) by usu2.usu.ru (Postfix) with ESMTP id 60183A7A32 for ; Mon, 19 Sep 2005 20:05:32 +0600 (YEKST) Received: from ums.usu.ru (ums.usu.ru [194.226.236.116]) by usu2.usu.ru (Postfix) with ESMTP id 55E1FA7A2F for ; Mon, 19 Sep 2005 20:05:32 +0600 (YEKST) 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 development list Hello, I am still writing a framebuffer driver for S3 Trio 3D/2X cards. Since this card supports (hardware) gamma correction in Windows 98, I decided to implement directcolor visuals (Xorg guys: you can set SR1B to 0x18 if bpp>8, and then standard VGA PEL registers will alter the hardware colormap). The problem here is that I don't know the proper semantics for colormap persistence. Consider the following scenario: fbset -depth 16 -rgba 5,5,5,1 -nonstd 1 run some program that sets a colormap, e.g. Xorg with the "fbdev" driver fbset -depth 16 -rgba 5,6,5,0 -nonstd 1 (oops, the text is all purple!) The problem is that the program sets the following colormap: reg 0 -> (0,0,0) reg 1 -> (8,4,8) ... reg 31 -> (255,125,255) reg 32 -> (0,129,0) reg 33 -> (0,133,0) ... reg 62 -> (0,250,0) reg 63 -> (0,255,0) (i.e. just a linear colormap for 16 bpp). When I switch the framebuffer to 15bpp, the colormap persists, but it is no longer a proper colormap for that mode! Is this colormap persistence an expected behaviour, or should I somehow initialize the colormap to something sane on depth switch? If that's a bug in my driver, could you please point me where some other driver does this colormap initialization? -- Alexander E. Patrakov ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php