Re: [ft-devel] Fw: HarfBuzz API design

[mpsuzuki]

Hi Werner,

On Sat, 22 Aug 2009 17:04:05 +0200 (CEST)
Werner LEMBERG <address@hidden> wrote:
>Something I think should be posted on this list too...
>
>Please subscribe to the harfbuzz mailing list if you are interested in
>the follow-ups to this mail.

Thank you for posting that. One of the most interesting
news in the message is that Behdad notices the support
of Unicode Variation Sequence in future HarfBuzz.

>Font callbacks
>==============

...

>typedef hb_codepoint_t
>(*hb_font_get_glyph_func_t) (hb_font_t *font, hb_face_t
>                              *face, const void *user_data,
>                              hb_codepoint_t unicode,
>                              hb_codepoint_t variant_selector);
>
>This is the cmap callback.  Note the variant_selector: it
>supports new cmap14 tables.  For older clients, they can
>ignore that argument and do the mapping. We probably will
>implement support for Unicode cmaps internally, but chain 
>to this function for missing-glyphs or if no suitable cmap
>was found.  That has three advantages:
>
>   - Pango etc can pass whatever code they want for missing
>     glyphs, to use later to draw hexbox,
>
>   - Pango, through fontconfig, knows how to handle non-Unicode
>     cmaps, so that will continue to work,
>
>   - For non-SFNT fonts, HarfBuzz should happily sit back
>     and make things work still, this is how that will work.

Regards,
mpsuzuki