unofficial mirror of emacs-devel@gnu.org 
 help / color / mirror / code / Atom feed
From: Augusto Stoffel <arstoffel@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: jporterbugs@gmail.com, stefankangas@gmail.com, emacs-devel@gnu.org
Subject: Re: Increase default `line-spacing' to 0.05, 0.10 or 0.15 [proposal]
Date: Thu, 06 May 2021 13:47:56 +0200	[thread overview]
Message-ID: <87a6p8w0b7.fsf@gmail.com> (raw)
In-Reply-To: <83mtt8dvft.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 06 May 2021 13:10:30 +0300")

On Thu,  6 May 2021 at 13:10, Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Augusto Stoffel <arstoffel@gmail.com>
>> Date: Thu, 06 May 2021 11:26:45 +0200
>> Cc: Jim Porter <jporterbugs@gmail.com>, emacs-devel@gnu.org
>> 
>> Comparing the picture in [1] and what I see if I put the block cursor
>> over an "H", I conclude that monospaced fonts come with some built-in
>> leading.  In other words, they are "bastard fonts" [2], and a nil for
>> `line-spacing' doesn't mean "solid" typesetting.
>
> I don't think this is true.  First, what you cite refers to so-called
> "manual typesetting", not to digital typography.  And second, the
> monospaced fonts we use define ascent and descent for each glyph, and
> we use that and nothing else (unless the font is broken, in which case
> we have fallbacks in place, but that's not relevant to the issue at
> hand).  AFAIU, the ascent and descent of each font glyph in a
> monospaced font is set up such that they accommodate both the tallest
> glyph and the lowest one.  Perhaps that is why you think they have
> some "leading", because you probably didn't examine all of the font's
> glyphs (we generally use as default fonts that cover many popular
> scripts).

Okay, we could ask a font designer if this standard glyph size is chosen
so as to provide a reasonable default leading (as I was assuming), or
merely to fit the ascent and descent of the tallest/deepest glyphs.  But
I would bet that the answer is both, since designing a font, especially
monospaced, involves lots of compromises.

Anyway, I think we can agree that setting `line-spacing' to nil is *not*
analogous setting \baselineskip=0pt in TeX.  That's all I wanted to
say there.

>> Kerning, tracking and other forms of microtypography are case-by-case
>> adjustments, intended to be basically subliminal, so I'd say yes, the
>> overall condensedness is pretty much a fixed characteristic of the font.
>> And these things are out of reach for Emacs anyway.
>
> They are not out of reach for us, because the shaping engine(s) we use
> know how to apply these features.  We just don't use them by default
> with most characters, that's all: we don't ask the text-shaping engine
> how to render each sequence of characters we need to display, we only
> ask it about some relatively rare sequences.  The reason for that is
> that under the current design of the display engine, calling the
> shaping engine is very expensive, as it requires calling out to Lisp,
> which then calls back into C.  So we only do that when necessary.  But
> a Lisp program can change that.

You are right, I should have said "these things [such as kerning] are
not relevant for monospaced fonts".



  reply	other threads:[~2021-05-06 11:47 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-04 15:57 Increase default `line-spacing' to 0.05, 0.10 or 0.15 [proposal] Stefan Kangas
2021-05-04 16:12 ` Óscar Fuentes
2021-05-04 16:59   ` Jim Porter
2021-05-05  7:08     ` Augusto Stoffel
2021-05-05  8:51       ` Daniel Mendler
2021-05-05 19:47       ` Stefan Kangas
2021-05-06  9:26         ` Augusto Stoffel
2021-05-06 10:10           ` Eli Zaretskii
2021-05-06 11:47             ` Augusto Stoffel [this message]
2021-05-06 11:57               ` Eli Zaretskii
2021-05-06 12:27                 ` Augusto Stoffel
2021-05-06 15:21                   ` Eli Zaretskii
2021-05-06 15:46                     ` Augusto Stoffel
2021-05-06 16:16                       ` Eli Zaretskii
2021-05-06 12:30                 ` Gregory Heytings
2021-05-06 15:22                   ` Eli Zaretskii
2021-05-06 16:21                     ` Gregory Heytings
2021-05-06 16:29                       ` Eli Zaretskii
2021-05-06 16:57                         ` Daniele Nicolodi
2021-05-06 17:53                           ` Eli Zaretskii
2021-05-06 17:57                             ` Eli Zaretskii
2021-05-06 20:24                             ` Daniele Nicolodi
2021-05-06 17:01                         ` Gregory Heytings
2021-05-06 17:34                           ` Eli Zaretskii
2021-05-06 18:15                             ` Gregory Heytings
2021-05-06 20:22           ` Stefan Kangas
2021-05-06 20:21     ` Stefan Kangas
2021-05-06 23:17       ` Jim Porter
2021-05-07  6:03         ` Yuri Khan
2021-05-07  4:05       ` Eli Zaretskii
2021-05-04 16:18 ` Eli Zaretskii
2021-05-04 21:29   ` Stefan Kangas
2021-05-05  2:28     ` Eli Zaretskii
2021-05-05  5:14 ` Richard Stallman
2021-05-05 19:16   ` Stefan Kangas
2021-05-06 20:21     ` Stefan Kangas
2021-05-07  4:03       ` Eli Zaretskii
2021-05-07 18:43         ` Stefan Kangas
2021-05-08  6:19           ` Eli Zaretskii
2021-05-08  7:51             ` Daniele Nicolodi
2021-05-08  8:06               ` Eli Zaretskii
2021-05-08  9:40                 ` Daniele Nicolodi
2021-05-05 12:18 ` Daniele Nicolodi
2021-05-05 19:17   ` Stefan Kangas

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87a6p8w0b7.fsf@gmail.com \
    --to=arstoffel@gmail.com \
    --cc=eliz@gnu.org \
    --cc=emacs-devel@gnu.org \
    --cc=jporterbugs@gmail.com \
    --cc=stefankangas@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).