Re: [Devel] FT_Face_GetAdvancesFunc

[Masatake YAMATO]

> >   typedef FT_Error
> >   (*FT_Face_GetAdvancesFunc)( FT_Face     face,
> >                               FT_UInt     first,
> >                               FT_UInt     count,
> >                               FT_Bool     vertical,
> >                               FT_UShort*  advances );
> >
> >   /*    get_advances     :: A function handle used to return the advances  
> > */
> >   /*                        of 'count' glyphs, starting at `index'.  the   
> > */
> >   /*                        `vertical' flags must be set when vertical     
> > */
> >   /*                        advances are queried.  The advances buffer is  
> > */
> >   /*                        caller-allocated.                              
> > */
> >
> > I cannot find `index' in the typedef.  Maybe the correct typedef is
> >
> >   typedef FT_Error
> >   (*FT_Face_GetAdvancesFunc)( FT_Face     face,
> >                               FT_UInt*    index,
> >                               FT_UInt     count,
> >                               FT_Bool     vertical,
> >                               FT_UShort*  advances );
> 
> I don't think so.  I rather believe that you simply should replace
> `index' with `first' in the documentation comment.
>
> > BTW, what is `advance'?  I guess the the advance is something like
> > kerning: kerning value between index[n-1] and index[n] is
> > advance[n].  Right?  Misunderstanding?
> 
> I think this is not correct.  `Advance' appears to be the advance
> value as stored in a font, in font units.

I misunderstood `advance'. I expected I can get kerning and/or
tracking value for glyph arrays.

> > If my guessing is correct, I propose to change the typedef to
> >
> >
> >   typedef FT_Error
> >   (*FT_Face_GetAdvancesFunc)( FT_Face     face,
> >                               FT_UInt*    index,
> >                               FT_UInt     count,
> >                               FT_Bool     vertical,
> >                               FT_Vector*  advances );
> >
> > So we can support cross-stream kerning like TeX.
> 
> Cross-stream kerning?  Standard TeX doesn't support this AFAIK, except
> if you use virtual fonts -- but then you can add almost arbitrary code
> into a glyph slot.  What exactly do you mean?

No. I'was talking about the logo, T X.
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