[ft] Regression of Andale Mono with v35 vs v40

[Fredrik Roubert]

Hello!

I just updated my Debian workstation to current "sid" and with that I
got an updated version of FreeType which, unfortunately, seems to give
me a rendering regression of the Andale Mono font (which I've grown very
attached to as a terminal font).

These are my installed Debian packages for FreeType and Fontconfig:

libfreetype6 2.8-0.2
libfontconfig1 2.12.3-0.2

I get the Andale Mono font from the file Andale_Mono.ttf which I once
downloaded from Microsoft using the Debian installer for the Microsoft
True Type Core Fonts, and it has file date 1998-11-12.

I've written two Fontconfig configuration files, one that explicitly
disables antialiasing and one that explicitly enabled antialiasing (see
attached files fonts.conf.noalias and fonts.conf.alias).

Then I've taken screenshots of Gnome Terminal, first with this:

export FREETYPE_PROPERTIES='truetype:interpreter-version=35'

Then with this:

export FREETYPE_PROPERTIES='truetype:interpreter-version=40'

As you can see in v35-noalias.png, the fully hinted rendering without
antialiasing works fine with v35, just as expected, but as you can see
in v40-noalias.png there is something seriously wrong with v40.

I suspect that this would have the same root cause as for the
differences seen in v35-alias.png and v40-alias.png, even though it
there isn't obvious that something is wrong with v40, the rendering is
just fuzzier than it was with v35.

Is this known behaviour?

For me personally, I have at the moment solved my immediate problem by
forcing the use of v35 but I'd like to figure out what to do going
forward.

Are there any settings that could get v40 to render Andale Mono like
shown in v35-alias.png?

Would it somehow be possible, using Fontconfig rules or something else,
to force the use of v35 only for this particular font?

The rendering shown in v35-noalias.png is something that I think that
v40 ought to be able to do. Isn't it? Is this a bug?

Cheers // Fredrik Roubert

-- 
Forsterstrasse 64  |  +41 78 8170377
CH-8044 Zürich     |  https://roubert.name/fredrik/

<?xml version="1.0" encoding="UTF-8"?>
<!-- vim: set ft=xml sw=2 sts=2 et: -->
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>

  <match target="font">
    <edit name="rgba" mode="assign">
      <const>none</const>
    </edit>
    <edit name="autohint" mode="assign">
      <bool>false</bool>
    </edit>
    <edit name="hinting" mode="assign">
      <bool>true</bool>
    </edit>
    <edit name="hintstyle" mode="assign">
      <const>hintfull</const>
    </edit>
    <edit name="antialias" mode="assign">
      <bool>false</bool>
    </edit>
    <edit name="lcdfilter" mode="assign">
      <const>lcdnone</const>
    </edit>
  </match>

</fontconfig>

<?xml version="1.0" encoding="UTF-8"?>
<!-- vim: set ft=xml sw=2 sts=2 et: -->
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>

  <match target="font">
    <edit name="rgba" mode="assign">
      <const>rgb</const>
    </edit>
    <edit name="autohint" mode="assign">
      <bool>false</bool>
    </edit>
    <edit name="hinting" mode="assign">
      <bool>true</bool>
    </edit>
    <edit name="hintstyle" mode="assign">
      <const>hintfull</const>
    </edit>
    <edit name="antialias" mode="assign">
      <bool>true</bool>
    </edit>
    <edit name="lcdfilter" mode="assign">
      <const>lcddefault</const>
    </edit>
  </match>

</fontconfig>