Re: [emacs-humanities] Optical Size Adjustment of Variable Fonts in Emacs

[Eli Zaretskii]

> Date: Thu, 8 Apr 2021 12:26:19 -0700
> From: Oliver Taylor via Emacs-humanities <emacs-humanities@gnu.org>
> 
> Most variable width fonts are optically smaller (meaning they look smaller) 
> than their monospace counterparts at the same point size, even those that are 
> designed to be used together.

Strangely enough, I don't see that optical effect, neither on my
system nor in the images you provided in the blog.  I guess this could
be individual.

> The relationship between the default, variable- and fixed-width faces is 
> somewhat complex and doesn’t easily allow you to optically correct your font 
> sizes in a way that works with both text-scale-adjust and in documents with 
> mixed pitches.

You have described the relationship correctly, but only for the
default case.  If the variable-pitch face and/or fixed-pitch face are
customized to be defined differently, for example, if they inherit
their size from some face other than the default face, your
conclusions might be wrong.  So some word of warning to the readers is
in order, I think.

The main issue to understand here is that faces are defined for a
frame, whereas buffer-face-mode is per-buffer.  the other important
issue is how face-remapping works, and which faces are affected when
you remap a particular face.  The latter still awaits a good writeup,
I think (although, of course, the source code has the entire story).

Thanks.