From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gerd =?UTF-8?Q?M=C3=B6llmann?= Newsgroups: gmane.emacs.bugs Subject: bug#74055: 31.0.50; color-lighten-name not lightening black Date: Tue, 29 Oct 2024 09:25:38 +0100 Message-ID: References: <86plnk766i.fsf@gnu.org> <86cyjk6sz7.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="27409"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: julien@danjou.info, Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= , noah@splode.com, 74055@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue Oct 29 09:27:30 2024 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 1t5hZa-0006uD-92 for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 29 Oct 2024 09:27:30 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t5hZE-0000hk-SW; Tue, 29 Oct 2024 04:27:09 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t5hZ9-0000cn-JH for bug-gnu-emacs@gnu.org; Tue, 29 Oct 2024 04:27:05 -0400 Original-Received: from debbugs.gnu.org ([2001:470:142:5::43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1t5hZ8-000685-O8 for bug-gnu-emacs@gnu.org; Tue, 29 Oct 2024 04:27:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debbugs.gnu.org; s=debbugs-gnu-org; h=MIME-Version:Date:References:In-Reply-To:From:To:Subject; bh=+qHTlB7NibMqhqP9UxNlqEqgji0hr9iB9KDd8oYWUG8=; b=C13kGm7lBt6nwinic+359UhxWHHTemCgVsI6UTh9tQT8L1JVY7UOqJ2489ZjgR6UkGrVGaZXHNLozqaXowJWYEiUFOALvHoLER/qK/qFVrM16yLemnqhwXdC+4niAKeZhJsna5A9h7K9Pa+m4H8k/RnS5BK/PgzOcEkAwZ1Nff+iKLczTrAJ+MCL/B+tTJ6Kx8mBFfPwv351c64ooOFR2p45v5J4tghX3FqmC2Z706O09fqwy/uY5SzhKyLifXHEv+ZYaNnjP4Xacexq9013KOGjlN1V1ohA39tLEaYbJwRv5ZpIPTZ+R3kqr6C9xPEj7wB9M9d5WvhJc8ot42KcqQ==; Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1t5hZ8-0002Wh-3x for bug-gnu-emacs@gnu.org; Tue, 29 Oct 2024 04:27:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Gerd =?UTF-8?Q?M=C3=B6llmann?= Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 29 Oct 2024 08:27:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 74055 X-GNU-PR-Package: emacs Original-Received: via spool by 74055-submit@debbugs.gnu.org id=B74055.17301904039669 (code B ref 74055); Tue, 29 Oct 2024 08:27:02 +0000 Original-Received: (at 74055) by debbugs.gnu.org; 29 Oct 2024 08:26:43 +0000 Original-Received: from localhost ([127.0.0.1]:55876 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1t5hYp-0002Vt-Bi for submit@debbugs.gnu.org; Tue, 29 Oct 2024 04:26:43 -0400 Original-Received: from mail-wm1-f45.google.com ([209.85.128.45]:48623) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1t5hYm-0002Vg-7T for 74055@debbugs.gnu.org; Tue, 29 Oct 2024 04:26:42 -0400 Original-Received: by mail-wm1-f45.google.com with SMTP id 5b1f17b1804b1-43152b79d25so47682275e9.1 for <74055@debbugs.gnu.org>; Tue, 29 Oct 2024 01:26:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1730190339; x=1730795139; darn=debbugs.gnu.org; h=content-transfer-encoding:mime-version:user-agent:message-id:date :references:in-reply-to:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=+qHTlB7NibMqhqP9UxNlqEqgji0hr9iB9KDd8oYWUG8=; b=f24vVHdK51XPh/5EFv/EYYjAA2wcFV8seoydrXtMxoRw5Bdb4OKQFp3YlgEl+CjwM2 zYX+4iJPJXN0OycrDbOajpXWN5L6CLVXSzIE3BHAjI5HJJfY6MdZsiAJm9fcWg9exjax w3jG0p3kBdhp+pL2AuhxNIOhTQhsyuAixO/iNZR9NbkMTDgL8ruiFIRdI2rYEJfpbiVN IoEVhxADspaSl6PNe+lkVNfA/OVYj/ppPvMPKr0vbWgUc+s1i1rNKf3DSKf3ZCfmF9ks 0BsYYy7BooeXqN9uC8DSZYIWMLsjqRoSFWBydROQwZbeHtiHJp5Mo3IU95X7K1u25XAZ jSEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730190339; x=1730795139; h=content-transfer-encoding:mime-version:user-agent:message-id:date :references:in-reply-to:subject:cc:to:from:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=+qHTlB7NibMqhqP9UxNlqEqgji0hr9iB9KDd8oYWUG8=; b=eyDPKzF0SLZTRySiMDIpjgF8QOlZLXFvzYPSlUPmZ/DBTosmPH3ZL37CRPAxuOLllW 5FyjWaob4XolRF0hizmqkG4WpC+QunxQ3yldS/P4lOuFjv1eOas1hRyAfk6g4PaXR3tU r/coFwReuOyBvsl5/6aDxMZRZTc+oswhqrGsUXSQFiFasacK87l5nhhugjEMU2jE29Kw M5Fdd3u5Koe2yTV+oT6UxvHcTc0YEmcawcRHtFbSJ7d+UQUrcNhpW+Y0I0oJuBighjhI Xy8++sUnmAxPThVymuzW4MsrgaJnf5P5hc+BvSiYj2aKcAow4xSlPHWCJLLfJ4VpmynY /WvQ== X-Forwarded-Encrypted: i=1; AJvYcCW/DK1AI1vzkhmpUyapuGK8oHtY3INcF0pH4cc+04d3jLa6BpHZECLBSK6ATBd47nBQlB0TFA==@debbugs.gnu.org X-Gm-Message-State: AOJu0YzZ6L8lR+ou7JUAolcrRTDyR85zoQ+5INKkeIsNoIWBOq9QQsaA 5jTbAjXrXTU17hFHS1/tGp71mEGHvTS9eaQaPf3BFfwbfj88ZZth X-Google-Smtp-Source: AGHT+IFfADXyIANBZ2Zk52QALkrFeLZVySHz7WWjBMfQQ9IvdDNGHVL51xdBb1aG8xu4iM5bt0/sQw== X-Received: by 2002:a05:600c:1d15:b0:431:4a83:2d80 with SMTP id 5b1f17b1804b1-4319ab94761mr93694395e9.0.1730190339244; Tue, 29 Oct 2024 01:25:39 -0700 (PDT) Original-Received: from pro2 (p4fe3a9b1.dip0.t-ipconnect.de. [79.227.169.177]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4318b56eda3sm166812605e9.31.2024.10.29.01.25.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Oct 2024 01:25:38 -0700 (PDT) In-Reply-To: ("Gerd =?UTF-8?Q?M=C3=B6llmann?="'s message of "Tue, 29 Oct 2024 05:41:59 +0100") 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-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:294473 Archived-At: Gerd M=C3=B6llmann writes: > Eli Zaretskii writes: > >>> From: Mattias Engdeg=C3=A5rd >>> Date: Mon, 28 Oct 2024 17:57:49 +0100 >>> Cc: Gerd M=C3=B6llmann , >>> Julien Danjou , >>> 74055@debbugs.gnu.org, >>> Noah Friedman >>>=20 >>> 28 okt. 2024 kl. 13.39 skrev Eli Zaretskii : >>>=20 >>> > Our notion of "lighten color" seems to be to increase the color's >>> > luminance by P percent. Since the black color's luminance is zero, >>> > increasing that by 50% still yields zero. >>> >=20 >>> > By contrast, the page you point to seems to interpret "lighten" to >>> > mean that P is the percentage of the full scale, not of the original >>> > color's luminance. >>> >=20 >>> > This goes back to commit 656c2dd66e, which was supposed to fix >>> > bug#54514. But maybe Noah's interpretation of "lighten" was >>> > incorrect, and we should revert that change? OTOH, if we do revert >>> > it, then Noah's example will disagree with the above page. >>>=20 >>> That change may have been made in haste. For example, it didn't >>> touch the corresponding saturate and desaturate functions which use >>> similar mechanics, so there is now an inconsistency in that respect. >>>=20 >>> But which interpretation is better isn't obvious. It doesn't have >>> much to do with colour theory per se. As luminance is already a >>> percentage of sorts, it's not at all clear what it means by >>> increasing it by a certain percentage. Personally I wouldn't use >>> either function because of how ill-defined they are. >> >> Maybe there are widely-accepted de-facto standards for that? > > I think HSL colors (Hue Saturation Luminescence) are used by CSS for > example, so that's good, and color.el has support for HSL colors. Except > that something is currently not working right, I guess. TIL the L in HSL actually stands for lightness. And the math for RGB <-> HSL conversion is nicely explained here: https://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/