Re: [ft-devel] Make FT_GlyphSlot_Embolden standard API?

[Shunsaku Hirata]

> > >I think glyph metrics should be changed automagically.
> >
> > Umm, yes, so, when fixed-width font is embolded, the result can be
> > proportional? I think there are many X applications (terminal emulators
> > and curses applications may be typical examples) which assumes/expects
> > the Hanzi glyphs are always fixed to full-width, regardless with
> > bold/oblique style. Therefore (if i'm not misunderstanding) switch
> > to enable/disable changing glyph metrics is required.
>
> If we don't change glyph metrics accordingly, won't the script be
> rendered wrongly (e.g. two glyphs comes too close)?

I think "correct result" depends on the script and also on intended use of
individual glyphs.

For examples, some Japanese font contains various glyphs for '2', '0', '5',
each glyphs having full-, half-, third-, or quater- (and proportional) widths.
In horizontal text "2005" placed within vertical writing, quater-width glyphs
may be used to make "2005" nicely fit into a single vertical line. In this
case, the result may be "wrong" for embolded glyphs if composition program
does not understand why quater-width version is choosed and if it does not
adjust widths as appropriate. (but I think it's ignorable.)

Maybe that's not something FreeType library should care, but some programs
that requires precise positioning of glyphs may not want glyph metrics to
be modified in uncontrollable manner. And I think keeping full-width always
to be full-width is the best way for CJK.


Regards,

Hirata