Re: [Freetype] Which script is covered by a font

[David Turner]

Hello Ingo,

Ingo Maier wrote:
> Maybe it is a stupid question but I found no information about that. Can
> I find out for which glyph indices there are glyph images in a font?
> Or better, can I find out which unicode scripts are covered by a given
> font?
There is no easy answer to this question. Fact is that:

  - in TrueType, the OS/2 table contains bit flags that
    indicates which Unicode ranges are covered by the
    font. However, DON'T EXPECT this information to be
    correct in all fonts out there, far from it.

  - other formats don't allow you to do that. The "generic"
    solution is thus to iterate over the charmaps found in
    the font to retrieve every possible (charcode=>glyph index)
    mapping, and build a "language coverage" out of these

you'll also need to store this information outside of the font
if you don't want to scan it each time you open it. This is
what I call "font meta-data". As far as I know, FontConfig
already provides this information on Unix.

Best Regards,

- David Turner
- The FreeType Project  (www.freetype.org)