Re: [ft-devel] FT_Get_PS_Font_Private in CFF driver

[Werner LEMBERG]

Hello Michael!


> I need to lookup the StdVW value that is in the Type1 private dict
> of an OpenType font (with CFF outlines).

Why?

> And since I already have the font loaded in FreeType, I was looking
> for a way to get the value from there.  But the
> FT_Get_PS_Font_Private service is not available in the CFF driver,
> it appears (-- the comment says "unsupported with CFF fonts").  One
> problem with CFF fonts is the fact that the font may have several
> sub fonts, I guess.

Exactly.  Additionally, in case of subfonts, the private dictionary of
the top-level font is empty.

> But on the other hand, the FT_Get_PS_Font_Info service _is_
> implemented by the CFF driver (by ignoring the sub fonts).

Yes, sub-fonts are ignored.  However, they aren't needed since only
the information of the top-level font info dictionary is returned.

> I do not know enough about the font specs to tell if it is okay to
> ignore subfonts for the Type1 font dict but not for the Type1
> private dict, but I consider implementing the private dict service
> along the lines of the available font dict implementation in
> cffdrivr.c.

This doesn't help in the general case: Which subfont's StdVW value do
you want to return?  Fonts like `ShinGo' have zillions of subfonts,
and most of them have different StdVW values.

> Do you have any comments on this? -- or do you have a suggestion for
> other ways of finding the StdVW value of a CFF font?

I need more information to give a qualified answer.


   Werner