Re: [Freetype] bytecode interpreter makes antialiased text worse?!

[Rogier van Dalen]

> What you see is normal. The TrueType hints are specifically written to
> distort the outline in such a way that this produces optimal monochrome
> glyphs. However, this distortion is very visible, and unpleasant when
> using anti-aliasing with a high number of gray levels...
>
> There is nothing that can be done for now, since we don't intend to modify
> the fonts :-)
>
> We could maybe patch the TrueType font driver in FT2 to use the bytecode
> interpreter _only_ when monochrome rendering is wanted, but this will
> generate glyphs with completely different metrics, and this may break
> some applications (which assume that a glyph's metrics are independent
> of the target hinting mode...)


I don't think the fact that Microsoft produces fonts that are optimised for
monochrome rendering is a good reason to auto-hint for anti-aliased
rendering.
Furthermore, TrueType does enable the instructions to find out whether aa
rendering is used (via the GETINFO structure). If a font does not use that
information, well, that means the instructions are buggy. No changes in the
renderer's behaviour can help that.
And programs that assume that a glyph's metrics don't change are buggy as
well, for the same reason.

Regards,

Rogier