Re: [emacs-bidi] using fribidi and Pango

[Eli Zaretskii]

> Date: Sun, 4 Dec 2005 16:24:28 -0500 (EST)
> From: Behdad Esfahbod <address@hidden>
> Cc: address@hidden
> 
> Fortunately a lot of data tables and other stuff can be replaced by
> FriBidi's structures, chopping some 500 lines of it I guess.

If you mean the tables of character properties, then these will
eventually go away in Emacs as well; see the FIXMEs there.

> The rest needs some restructuring.

What kind of restructuring, and why is it needed?

> But then the question is, is the API usable in more than Emacs
> only?

Potentially, any display engine that needs to examine text one
character at a time.

> Even an array containing the input text is being problematic.
> There's always someone asking for UTF-8, one for UTF-16, another for
> UTF-32.

You will see that my code calls a bunch of macros to fetch characters.
Any general-purpose library needs to give these or similar
macros/functions to the caller as part of the API, because each caller
will have its own way of walking the characters.  Those functions will
also take care of converting from whatever representation they use for
characters into Unicode codepoints.

> I'm more interested to see the highlevel PangoLayout object
> extended to cover needs of applications like Emacs and AbiWord.

I doubt that heavyweight display monsters like Emacs will ever
delegate the layout job to libraries.

> And I'm willing to hear more about those needs :).

What do you want to know?

In general, reading xdisp.c and dispnew.c in Emacs sources will give
you some ideas about what's involved.