Re: listing the supported file formats

[Werner LEMBERG]

> Hello, I've recently started doing more in-depth development with
> Freetype2 and I was wondering if there was a way to list, or build a
> list of, the file formats supported by freetype or any extended
> modules when supplying a filepath to `FT_New_Face()`.
> 
> If freetype doesn't support a format, I would like to avoid calling
> `FT_New_Face()` entirely, rather than receiving an error for an
> unsupported format. :)

How do you know that font file X has format Y?  If you are a Windows
user you might say 'look at the extension of X'!  Such a thing doesn't
exist on GNU/Linux in general.  For example, PostScript font resources
are often files without an extension at all.

Note that even on Windows the extension check is not reliable: As an
example, both TrueType and OpenType Collections normally get the same
extension (`.ttc`).

In other words, you *must* parse a font with FreeType to find out its
type.  This is exactly what `FT_New_Face` does, as fast as possible,
if you specify -1 as the value for the function's `face_index`
parameter.

> If you could also improve the documentation to describe this
> process, it would be very helpful to avoid errors entirely. :)

What process shall be described?


    Werner