[HarfBuzz] Determine whether font contains a glyph for a sequence of code points

[Richard Wordingham]

On Fri, 15 Feb 2019 11:10:48 -0800
Behdad Esfahbod <behdad at behdad.org> wrote:

> Shape and check the result.

> On Fri, Feb 15, 2019, 9:24 AM Konstantin Pozin via HarfBuzz <
> harfbuzz at lists.freedesktop.org> wrote:  

> > What is simplest (and ideally, most performant) way to check
> > whether an hb_font_t contains a glyph for a sequence of code
> > points?

Of course, that wouldn't detect an AB ligature that was only formed in
the sequence ACB or DAB or ABE.  There are Arabic fonts where the vowel
marks affect the shaping of the consonant frame, so it's not impossible.

There's a potential for fun with dotted circles introduced by the shaper
for defective sequences.

Richard.