From mboxrd@z Thu Jan 1 00:00:00 1970 From: Damien Lespiau Subject: Re: [PATCH 3/4] drm/i915: Enabling pre-multiplied alpha drm property Date: Thu, 20 Mar 2014 14:00:05 +0000 Message-ID: <20140320140005.GP6912@strange.amr.corp.intel.com> References: <1394266879-20522-1-git-send-email-sagar.a.kamble@intel.com> <1394266879-20522-4-git-send-email-sagar.a.kamble@intel.com> <20140319151008.GB27717@strange.amr.corp.intel.com> <1395309582.2740.9.camel@sagar-desktop> <20140320113818.GL6912@strange.amr.corp.intel.com> <20140320135120.GN30571@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id 6B2276E09D for ; Thu, 20 Mar 2014 07:00:53 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20140320135120.GN30571@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Daniel Vetter Cc: "Srinivas, Vidya" , David Airlie , Daniel Vetter , intel-gfx@lists.freedesktop.org, Sagar Arun Kamble List-Id: intel-gfx@lists.freedesktop.org On Thu, Mar 20, 2014 at 02:51:20PM +0100, Daniel Vetter wrote: > I don't really have a decent opinion on the pre-multiplied vs > non-premultiplied ARGB formats issue at hand. In case of doubt I think we > should follow what gl does. But I have no clue how that's handled in gl > ;-) I'd still like a premultipled DRM format, but let's wait for Ville opinion. In GL, the blending equation doesn't do anything automatically. So if you have a premultiplied source, you need to setup the blending function/factor accordingly. -- Damien