title: How to create FT_Face from the CGFontRef of a system font in iOS?
body: <p>In iOS, you don't know the font file path(I mean, though you can see them at somewhere of /System, there is no API for you to get a font's path, they may be changed in future), the way to access font is by its name eg. <code>[UIFont fontWithName...]</code>, <code>CGFontCreateWithFontName</code> etc..</p>
  
  <p>I need to use FreeType in my project, and I want to convert the <code>CGFontRef</code> to <code>FT_Face</code>, but as mentions above, I can't get the font's file path, so I wonder if there is some way to create <code>FT_Face</code> from <code>CGFontRef</code>?</p>