Re: [Devel] Truetype charmap matching algorithm

[David Turner]

Hello Stephen,

stephenfung wrote:
> I am working on algorithm of 
>
> input: unicode of character
> output: the glyph of that character (ie the location of that glyph in
> TTF, say)
>
> However, as i found in the function of FT_Get_Char_Index 
> [ftobjs.c (1714)]
>
> result = cmap->clazz->char_index( cmap, charcode );
>
> and i cannot follow the function pointer of char_index any more.
Which is normal, since the function depends on the font format being
used. For TrueType fonts, have a look at the content of
"src/sfnt/ttcmap0.c" or even the now obsolete "src/sfnt/ttcmap.c"
(which we keep for reference)

> Can anyone tell me the flow of how unicode match with glyph in common
> usage?
Depends on the font format. For Postscript fonts, we generally synthetize
an artifical charmap from the glyph names themselves. Otherwise, we use
the charmap available in the font file (TrueType,PFR,etc..)

Regards,

- David Turner
- The FreeType Project  (www.freetype.org)


--
This message and any attachments (the "message") is intended solely for the
addressees and is confidential. If you receive this message in error, please
delete it and immediately notify the sender.
Any use not in accordance with its purpose, any dissemination or disclosure,
either whole or partial, is prohibited except formal approval.
The E-Mail transmission can not guarantee the integrity of this message.
CANAL+TECHNOLOGIES will not therefore be liable for the message if modified.