Re: [IDEA] Facilities to extract TT fonts from TTC font collections

If you don't need to do this from C necessarily, check out ftCLI:

  https://github.com/ftCLI/FoundryTools-CLI

Or "fonttools ttLib --help" from fonttools:

  https://github.com/fonttools/fonttools

behdad
http://behdad.org/


On Mon, Oct 23, 2023 at 6:44 AM Francesco Pretto <[email protected]> wrote:

> Hello,
>
> I recently had to extract a TrueType font from a TTC font collection
> as part of fixing bugs in the podofo library[1]. Since I couldn't find
> an API suited for the task, I found myself in need to manually parse
> the TTC Header, which is not a type exposed in the FreeType public
> API. I believe FreeType could have helped me much better if, for
> example, it would have provided a way to extract the actual face Table
> Directory[2] from the font data. For example, a special tag TTAG_tdir
> could be defined to access the raw Table Directory data with
> FT_Load_Sfnt_Table, like the following:
>
> FT_ULong size = 0;
> FT_Load_Sfnt_Table(face, TTAG_tdir, 0, NULL, &size);
>
> Interestingly enough, Windows GetFontData[3] seems to do something
> similar (but with inverted semantics) when using the special table
> "0", while to access whole file in case of collections it uses the
> special ttcf "table tag".
>
> Since I already crafted my own solution, I'm not in a rush for
> improvements in FreeType, but it could be something good to have in a
> future release.
>
> Regards,
> Francesco
>
> [1]
> https://github.com/podofo/podofo/blob/df36740b176fa535a8dc6dfc5a1b940f84710aa8/src/podofo/private/FreetypePrivate.cpp#L177
> [2]
> https://learn.microsoft.com/en-us/typography/opentype/spec/otff#table-directory
> [3]
> https://learn.microsoft.com/en-us/windows/win32/api/wingdi/nf-wingdi-getfontdata
>
>