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".
next prev parent 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
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