From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: CSS contrast (#30295) (was Re: Heads-up: Emacs 26.1 RC1) Date: Wed, 21 Mar 2018 14:47:32 +0200 Message-ID: <83y3ilk32z.fsf@gnu.org> References: <83muz2lfo9.fsf@gnu.org> <837eq5lvyx.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1521636743 5088 195.159.176.226 (21 Mar 2018 12:52:23 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 21 Mar 2018 12:52:23 +0000 (UTC) Cc: johnw@gnu.org, tom@tromey.com, emacs-devel@gnu.org To: Richard Copley Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Mar 21 13:52:19 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eydE2-0001DC-SP for ged-emacs-devel@m.gmane.org; Wed, 21 Mar 2018 13:52:18 +0100 Original-Received: from localhost ([::1]:54806 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eydG4-00059P-CV for ged-emacs-devel@m.gmane.org; Wed, 21 Mar 2018 08:54:24 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35343) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eyd9I-00079t-LQ for emacs-devel@gnu.org; Wed, 21 Mar 2018 08:47:25 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eyd9H-0000Ht-Qw for emacs-devel@gnu.org; Wed, 21 Mar 2018 08:47:24 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:49898) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eyd9C-0000FG-T1; Wed, 21 Mar 2018 08:47:18 -0400 Original-Received: from [176.228.60.248] (port=2744 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1eyd9C-0000RQ-9S; Wed, 21 Mar 2018 08:47:18 -0400 In-reply-to: (message from Richard Copley on Wed, 21 Mar 2018 11:34:47 +0000) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:223885 Archived-At: > From: Richard Copley > Date: Wed, 21 Mar 2018 11:34:47 +0000 > Cc: John Wiegley , Tom Tromey , > Emacs Development > > Is the current criterion (use white text on backgrounds inside a sphere of a given radius centred on black, in > the color-distance metric space) a standard way of doing things? We do something very similar in frame-set-background-mode and in tty-color-approximate. Also note that color-distance is based on a metric that we didn't invent. Not sure whether it makes that "standard". > I'm not saying that the luminance-less-than-50% calculation is a standard, either, but I've seen it used before, > which is more than I can say for the color-inside-a-sphere calculation. > I'm also not saying that color-distance is any more or less "invented" than luminance. I'm not dismissing these arguments, I'm just saying that it's too late to raise them for what will become Emacs 26.1. We can make those changes on master, if people agree with your reasoning, or we could use the contrast criterion there, or something else. But for the release branch, the only change I can think of which will allow you to get what you want in a safe way is the one I proposed: introduce a customizable threshold.