From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings Newsgroups: gmane.emacs.devel Subject: Re: Increase default `line-spacing' to 0.05, 0.10 or 0.15 [proposal] Date: Thu, 06 May 2021 17:01:36 +0000 Message-ID: <531453ddd665244d7826@heytings.org> References: <871ramlbpy.fsf@telefonica.net> <87fsz1zmhv.fsf@gmail.com> <87sg30usa2.fsf@gmail.com> <83mtt8dvft.fsf@gnu.org> <87a6p8w0b7.fsf@gmail.com> <83h7jgdqhs.fsf@gnu.org> <531453ddd626d93fbb46@heytings.org> <83czu3evks.fsf@gnu.org> <531453ddd6aad581d339@heytings.org> <831rajesgw.fsf@gnu.org> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="e68ENW12BJ" Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39019"; mail-complaints-to="usenet@ciao.gmane.io" Cc: jporterbugs@gmail.com, arstoffel@gmail.com, stefankangas@gmail.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu May 06 19:04:25 2021 Return-path: Envelope-to: ged-emacs-devel@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 1lehQG-000A1B-WD for ged-emacs-devel@m.gmane-mx.org; Thu, 06 May 2021 19:04:25 +0200 Original-Received: from localhost ([::1]:38638 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lehQG-0004xf-2o for ged-emacs-devel@m.gmane-mx.org; Thu, 06 May 2021 13:04:24 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:53334) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lehNh-0003cT-1M for emacs-devel@gnu.org; Thu, 06 May 2021 13:01:46 -0400 Original-Received: from heytings.org ([95.142.160.155]:44328) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lehNb-0003fy-3x; Thu, 06 May 2021 13:01:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heytings.org; s=20210101; t=1620320496; bh=MY/42TESBuzu1FB2AizNVPLHjEmVUOQJEoxwk+eQtR4=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:From; b=izQKiaceszl3TuP3ZGH/YCynPXvTDncCRAskR9/r2Q7VZhn5vnF+Qx4s8OHqNlZ0c M3NiZV73u3GrWTFJuZox+gRxtS1vUIeeOSzG/3gIPzDeSuopgTwduYbRalFX1HdaF3 +XjK4H/moigGxvAocjjdwBhLs5oB73BA4A3RfMyczxiUMoHbtIqzpRHyZtPByJd9WG dxnt1+FwEymQhwdG6SOSRL2UhYP2lJIlCcg79+f4sN/uHceAddc9NmZdowlUtG4IIk b6F99gBLMCgyauh2I2KyU4JQZwZh3PvHiir3eJbjonM+IOAHTGC7H354sOrA+PrU9W Ts+pme1PjCx7Q== In-Reply-To: <831rajesgw.fsf@gnu.org> Received-SPF: pass client-ip=95.142.160.155; envelope-from=gregory@heytings.org; helo=heytings.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:268979 Archived-At: --e68ENW12BJ Content-Type: text/plain; format=flowed; charset=us-ascii >>>> \baselineskip=0pt means that the height and depth of a text line is >>>> equal to the maximal height and depth of the characters in that line. >>>> See the attached two screenshots that demonstrate the difference. >>> >>> That's what Emacs does as well, when line-spacing is nil, but Augusto >>> says they are different. >> >> Unless I'm missing something, that's not what Emacs does, no. I attach >> two screenshots of the exact same text with the exact same font, one >> with Emacs (setq line-spacing nil) and the other with TeX >> (\baselineskip=0pt). The effect is very different. > > Then your description of what TeX does is probably incomplete or > inaccurate. > The TeXbook says: "Whenever a box is added to a vertical list [i.e., a line is added to a page under construction], TeX inserts "interline glue" intended to make the distance between the baseline of the new box and the baseline of the previous box exactly equal to the value of \baselineskip." In more detail, the line-spacing algorithm also uses \lineskip, whose default value is 1pt. If you set both \baselineskip and \lineskip to 0pt, there is no vertical space whatsoever between the lines, see the attached screenshot. > > on the Emacs side, I can point you to the code which implements > line-spacing, which clearly shows that if line-spacing is nil, the > default, we add NOTHING (a.k.a. "zero") to the height of the line, > leaving it at its computed value of the sum of the maximum ascent and > maximum descent of the glyphs in that line. > Of course I trust you. Perhaps Emacs has a different understanding of what the ascent and descent of a glyph is? Otherwise a line of dots would use less vertical space than a line of X's, which is what happens with TeX with \baselineskip=0pt and/or \lineskip=0pt. Anyway, I'm not sure all this is really important for this discussion. --e68ENW12BJ Content-Type: image/png; name=tex.png Content-Transfer-Encoding: base64 Content-ID: <531453ddd6fc630ff30c@heytings.org> Content-Description: Content-Disposition: attachment; filename=tex.png iVBORw0KGgoAAAANSUhEUgAAAgIAAACQCAAAAABfH1xxAAAFKUlEQVR42u2c TWgcZRzGn2mSsrrGEIlJxBpNaUirZqn0Qy8qjdhDKR5axPpBBQ9eiggKgvgB xYsHg3gRDx4EQYQKPYkK1kAtVJKDNtVYURuTtGnZ2oR2mzRG7Oth11lnZ2bz LgSa+T/P7zKTZ3+z5PAwszP77j9wENysud7/gLjeqAL0qAL0qAL0qAL0qAL0 qAL0qAL0qAL0qAL0qAL0qAL0qAL0qAL0qAL0qAL0qAL0qAL0qAL0NDciH5rs 3C/DmhGkLR89WCxvX7+tmj3yTeGEjOwbNbgU1ldeP/m/bBAFGQaMKKkXgq3d AH4rRrKBxT4ZBowaXD2ei3ZJhiEjRHcE9PjeEVz5EABw69MyzBmep5Ppsl2Q YcUI8T0LtL4E4NC0DHuGbwXahgD8MC3DnqGPg/SoAvSoAvSoAvSoAvTUr8Df y94yyMiqEVK/AheAVsgwaYQkViBcQzCD5k7IsGTESazA0Pvlt/p9DAMtkGHJ iJNYgdKBR79Yght/CtiXfJiMrBpxUj4zHDkSdF1eAPpfSDtQRlaNGEnfHf3x 2l0AgKYnL0Ty6vIjGVk14qQtHz07NZnf0JuLhg8eu/87GZk3anEN0IsnZJgz Gnk6ODqBu2WYMwK/MdSTP8OderuYm+iWYc3wvBC8CwBo+kCGPSP9QXLpF2BT vvLHzT1Ax527C/N5GQaMKKnlGAZwXIHJIIK+LKZHFaBHFaAn9aZw7p/ytr2p mu0eLhyXkX0jSvovi0+XtyfvrWZXFxZkGDCi6EJAT+pZ4OMFAENfRrJ3LrbK MGDU4OqxWn4LL2PljRBdCOjxXWk8swkAMHBMhjXDtwLXLgMASjLMGb4XgttL pVLpYRkGDd+zQHATgCYZBg19HKRHFaBHFaBHFaBn2QoEy76FjKwaZepX4BJw A2SYNELqV6AItEOGSSMksQIjV8rbpZ/QmfxGMrJqxEmswOeFbwEAH81iMPkw GVk14iQ/HZx4aNvOnksjnyF4MeU4GVk1YiRWYH1ucXQUAIL3Hkg+TEZWjTiJ FXh2z+GjU5P5DX37+2teCWRk3EjAc2mJc865zdgpw5zRyNPB+V/RK8Oc0UAF 3Kvz2CXDnuG8+HT79m1twBYZ9oyG5gvsuijDnpE+ZaR0aq5943+rz8dHgNb8 mmogI8tGlJRqnN7TAmDt3gkF5oIaUirwfRuALgDtJxQYCzwrsBk4eN6dfwvY qsBY4FeBr4CXnXPOvQIMKzAVeFbgMQRnnHPOnQ2wV4GpwLMCfeFJYwvuUWAq iJH8dPAM1lX21mFKgakgRmIFZq+io7LbgVJJgaHAswI3AouV3UUEOQWGAs8K 5DrwZ2W3iO4WBYYCzwrgDoyVHxxf+xE9CkwFnhXYgZnyRIKj57BDgakgTuJ9 wnQzCnPOudkBrD2nwFQQI+UB8fPAxjcPv9EPHFBgLPCswF+PV04S+5YUGAtq SV0v8PUnY7O3FJ4ZVGAviKIZxIRGFM0gJjSiaMQEPZpBTGjU4OqxWublylh5 I0QXAno0g5je0AxiekMziOkNzSCmN/RxkB5VgB5VgB5VgB7NICY2ymgGMasR ohnErEaIZhCTGXE0g5jMiKMZxGxGDM0gJjPiaAYxmZGA59IS59xqmJcrY+UN zSCmNzSDWIbzYrXMy5Wx8oZmENMb6TOII4yPAF33dcswaHhWQNhF6wXoUQXo UQXoUQXoUQXoUQXoUQXoUQXoUQXoUQXoUQXoUQXoUQXoUQXoUQXoUQXoUQXo UQXoUQXo+Rfr/IhIqFhqfwAAAABJRU5ErkJggg== --e68ENW12BJ--