simon-git: technicality (main): Simon Tatham

[Commits to Tartarus hosted VCS]

TL;DR:
  8d115c1 Work around a bug in Fontforge's simplifier.

Repository:     https://git.tartarus.org/simon/technicality.git
On the web:     https://git.tartarus.org/?p=simon/technicality.git
Branch updated: main
Committer:      Simon Tatham <anakin at pobox.com>
Date:           2025-05-01 17:05:54

commit 8d115c17837986f9236668eda32f963640b33bb4
web diff https://git.tartarus.org/?p=simon/technicality.git;a=commitdiff;h=8d115c17837986f9236668eda32f963640b33bb4;hp=b6ae0e522d1f8576a623a3776aeffcea2c443e09
Author: Simon Tatham <anakin at pobox.com>
Date:   Wed Apr 30 16:25:56 2025 +0100

    Work around a bug in Fontforge's simplifier.
    
    A user (wow, a user!) reported that on Windows 11 these fonts had
    twice the line spacing they should, in the form of a huge descender
    section. That turned out to be because the OS/2 winDescent metric was
    more like 1500 design units than the expected 200. That in turn was
    caused by some glyphs having a huge bounding box, which was apparently
    introduced when I called contour.simplify().
    
    (I wasn't seeing the wrong line spacing on _my_ Windows machine. But
    that's Windows 10, so I have to guess that some change in OS font
    handling affects which of the 'descent' header fields to use.)
    
    I have no idea what contour.simplify() is playing at. I've done the
    very simplest workaround, which is to check whether the bounding box
    of a contour has hugely increased during simplification, and if so,
    revert to the unsimplified version!
    
    With this change, the metrics go back to being reasonably sensible.

 gfparse.py | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)