From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Newsgroups: gmane.emacs.bugs Subject: bug#41544: 26.3; Possible incorrect results from color-distance Date: Tue, 2 Jun 2020 17:27:46 +0200 Message-ID: <77F1DDD3-A69F-40ED-902D-74986D5E6596@acm.org> References: <5C4A633D-8222-4439-BE37-9B8674F1DA6D@acm.org> <87r1v2aat3.fsf@tromey.com> <9902865C-01B4-4E50-A433-DBC8B8311234@acm.org> <83tuzueogo.fsf@gnu.org> <6272275C-560C-4437-90F1-2A8294D27019@acm.org> <83o8q2elja.fsf@gnu.org> <83mu5mel4o.fsf@gnu.org> Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.14\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="98995"; mail-complaints-to="usenet@ciao.gmane.io" Cc: tom@tromey.com, simon@polaris64.net, 41544@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue Jun 02 17:28:11 2020 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jg8pm-000Pbx-DZ for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 02 Jun 2020 17:28:10 +0200 Original-Received: from localhost ([::1]:60480 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jg8pl-00009R-FI for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 02 Jun 2020 11:28:09 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:51052) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jg8pe-00009K-RB for bug-gnu-emacs@gnu.org; Tue, 02 Jun 2020 11:28:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:57305) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jg8pe-0001ny-Hq for bug-gnu-emacs@gnu.org; Tue, 02 Jun 2020 11:28:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jg8pe-0008NI-EJ for bug-gnu-emacs@gnu.org; Tue, 02 Jun 2020 11:28:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 02 Jun 2020 15:28:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 41544 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 41544-submit@debbugs.gnu.org id=B41544.159111167532174 (code B ref 41544); Tue, 02 Jun 2020 15:28:02 +0000 Original-Received: (at 41544) by debbugs.gnu.org; 2 Jun 2020 15:27:55 +0000 Original-Received: from localhost ([127.0.0.1]:40618 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jg8pW-0008Ms-TT for submit@debbugs.gnu.org; Tue, 02 Jun 2020 11:27:55 -0400 Original-Received: from mail171c50.megamailservers.eu ([91.136.10.181]:54736 helo=mail92c50.megamailservers.eu) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jg8pU-0008Me-57 for 41544@debbugs.gnu.org; Tue, 02 Jun 2020 11:27:54 -0400 X-Authenticated-User: mattiase@bredband.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megamailservers.eu; s=maildub; t=1591111670; bh=EiRxBbGhp6jfAwN+XKHGCHyTCvyBKXYNBE+Pu6v3iZ0=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=UcSvF0UUWQSxPwrqTwzs/BoIGlAD8nblBpPKhR9z5MuFm88I9BceOjdU8J9jdRCMq aotBJrMNAsSJVWdLS7yWm+uDfpXbra0BiXFQe/ilcUbSkYOxH0q1hJ6ZitjXfkYNy4 cJyRz6Z18FeZ8kj50/9/Fgd8D9U6JnlpU/dbLUHQ= Feedback-ID: mattiase@acm.or Original-Received: from stanniol.lan (c-4e4ae655.032-75-73746f71.bbcust.telenor.se [85.230.74.78]) (authenticated bits=0) by mail92c50.megamailservers.eu (8.14.9/8.13.1) with ESMTP id 052FRlL5027557; Tue, 2 Jun 2020 15:27:48 +0000 In-Reply-To: <83mu5mel4o.fsf@gnu.org> X-Mailer: Apple Mail (2.3445.104.14) X-CTCH-RefID: str=0001.0A782F27.5ED66F9C.006E:SCFSTAT68638221, ss=1, re=-4.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0 X-CTCH-VOD: Unknown X-CTCH-Spam: Unknown X-CTCH-Score: -4.000 X-CTCH-Flags: 0 X-CTCH-ScoreCust: 0.000 X-CSC: 0 X-CHA: v=2.3 cv=aY8fYigt c=1 sm=1 tr=0 a=klNLuyVZdLUgl+K5Uafb2A==:117 a=klNLuyVZdLUgl+K5Uafb2A==:17 a=kj9zAlcOel0A:10 a=M51BFTxLslgA:10 a=mDV3o1hIAAAA:8 a=cU5vsblOPORyMJlAhFAA:9 a=CjuIK1q_8ugA:10 a=_FVE-zBwftR9WsbkzFJk:22 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:181405 Archived-At: 1 juni 2020 kl. 19.44 skrev Eli Zaretskii : >> I'm just looking at the changes. I see a change in how colors are >> converted to RGB triplets. I see a change in what colors are >> considered dark and light, with a new function which decides that = that >> is being used for frame background mode and in several lisp/term/ >> files, including 16-color terminals. I'm asking why do we want to >> make all those changes, which modify very basic aspects of our color >> support on many terminals. >=20 > And then, of course, there are the changes in color-distance itself, > which change the values it returns. Again, why such significant > changes to fix an otherwise insignificant bug? It is difficult to give precise answers to vague complaints. Take one = thing at a time: as I wrote, there are two different patches addressing = two almost completely different issues. Let's start with the = color-distance changes, out of respect for the bug reporter if nothing = else. It is not possible to change a function without changing it. Either we = fix it or we don't. The reported bug was about broken symmetry, which is = rather embarrassing; as written previously, the first analysis uncovered = deeper issues worth fixing, such as loss of precision and (especially) = the nonlinearity that causes triangle inequality violation. The proposed fixes to color-distance, I hope you agree, are = straightforward, reasonable and address all these points. Callers have = been updated with carefully recomputed comparison constants; I detailed = how they were obtained in a previous reply, and test have all been = satisfactory.