Re: Bug#190672: 3 vs 9

[Michael Fedrowitz <michaelf debian org>]

On Fri, Apr 25, 2003 at 12:58:42PM -0400, Joey Hess wrote:

 Hi,

> I sopke too soon, fontconfig 2.2.0 does get dir of the AA, but that does
> not really help the problem. The leftmost pixel of the top of the 3 is
> now solid white instead of antialiased, which merely makes it visually
> closer to a 9.

I'm really surprised that fontconfig 2.2 changed anything at all. AFAIK
it changes nothing about anti-aliasing (and using the Vera fonts without
AA is generally not a good idea anyway). The only thing that it does is
turning off hinting for the Vera fonts, but only at pixel (not point!)
sizes below 7.5. Now what you could try is something like this

  <match target="font">
    <test name="family">
      <string>Bitstream Vera Sans Mono</string>
    </test>
    <test name="size" compare="less_eq">
      <double>8.0</double>
    </test>
    <edit name="hinting">
      <bool>false</bool>
    </edit>
  </match>

to turn off hinting for Vera Sans Mono at point size 8 and below. This
should definitely give you a much more readable '3', however it will
also change the shapes of all glyphs to some degree. You will just have
to try and see if you like it. Another possibility would be to use the
autohinter instead of the bytecode interpreter, but while this gives you
a readable '3', it unfortunately makes the 'm' look way off (at least
with the FreeType currently in sid).

Of course nothing of this addresses the real problem, which is IMHO that
the hinting of the '3' pulls the upper part so far down that there is
only one pixel between points 21 and 31, and if that pixel now gets
partially shaded by anti-aliasing... It would be nice if the hinting
could be tweaked to always leave at least two pixels between these two
points down to a pixel size of maybe 9 or so (though this is probably
easier said than done...).

-Michael