From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: David De La Harpe Golden Newsgroups: gmane.emacs.devel Subject: Re: Changes 2009-07-15/16 in branch? Date: Tue, 28 Jul 2009 21:33:21 +0100 Message-ID: <4A6F6091.1000906@harpegolden.net> References: <4A692E0A.9060108@gnu.org> <4A6E0A8E.3030407@harpegolden.net> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1248813312 3564 80.91.229.12 (28 Jul 2009 20:35:12 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 28 Jul 2009 20:35:12 +0000 (UTC) Cc: Emacs-Devel devel To: Adrian Robert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Jul 28 22:35:05 2009 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1MVtO4-0000Rs-GN for ged-emacs-devel@m.gmane.org; Tue, 28 Jul 2009 22:35:04 +0200 Original-Received: from localhost ([127.0.0.1]:51722 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MVtO3-0004LJ-T8 for ged-emacs-devel@m.gmane.org; Tue, 28 Jul 2009 16:35:03 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MVtMd-0002yo-O3 for emacs-devel@gnu.org; Tue, 28 Jul 2009 16:33:35 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MVtMZ-0002sW-Qj for emacs-devel@gnu.org; Tue, 28 Jul 2009 16:33:35 -0400 Original-Received: from [199.232.76.173] (port=33596 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MVtMZ-0002s6-KQ for emacs-devel@gnu.org; Tue, 28 Jul 2009 16:33:31 -0400 Original-Received: from harpegolden.net ([65.99.215.13]:59582) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MVtMZ-00087M-6g for emacs-devel@gnu.org; Tue, 28 Jul 2009 16:33:31 -0400 Original-Received: from [87.198.54.192] (87-198-54-192.ptr.magnet.ie [87.198.54.192]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "David De La Harpe Golden", Issuer "David De La Harpe Golden Personal CA rev 3" (verified OK)) by harpegolden.net (Postfix) with ESMTP id A1A5781AF; Tue, 28 Jul 2009 21:33:28 +0100 (IST) User-Agent: Mozilla-Thunderbird 2.0.0.22 (X11/20090701) In-Reply-To: X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:113301 Archived-At: Adrian Robert wrote: > This sort of thing [in-emacs alphablending] would likely layer > over alpha support at the lower level such as that provided by the NS port. Not necessarily at all, all realised colors could be without alpha, the idea was raised in the context of 256-color terminal users in fact where alpha computations would be internal to emacs. (otoh might as well pass it through if it's also there at the OS level, but that would just be a "final alpha" as an output of the blending process). > Does emacs support rgb(r, g, b) or rgb:r/g/b already? > The latter on X11, but N.B. it's really X11 itself supporting it, not emacs - i.e. emacs directly asks X11 for colors via the libX11 XParseColor() API [1] (internally emulated on most other platforms and text terminals IIRC) X11 supports a range of device-dependent and (rather obscure for most people) device-independent color specification strings, as well as previously mentioned well-known and user-defined names for those colors. (None include alpha since alpha isn't historically part of the X color) Given your interest is alpha and hsv (hsl is neater...), maybe imitating the CSS2/3 syntax which includes alpha might be better - and is more likely to avoid clashing if X.org extend XParseColor() one fine day. CSS syntax could also serve to indicate an sRGB colorspace interpretation of rgb triples. rgb() rgba() hsl() hsla() [1] http://linux.die.net/man/3/xparsecolor e.g. rgb:// rgbi:// CIEXYZ:// CIEuvY:// CIExyY:// CIELab:// CIELuv:// TekHVC://