Re: How to convert char from Emacs-20 internal to UTF-8?

[Adrian Robert <arobert@cogsci.ucsd.edu>]

> The trunk of the CVS repository (which will becomes Emacs-22)
> already supports OS X (via Carbon).
>
> If that doesn't help you because you want to use some other
> API, I recommend you start from the emacs-unicode-2 branch in
> the CVS repository (which may become Emacs-23).  That branch
> changes the internal character set of Emacs to Unicode, so you
> won't need to convert chars at all.
>
> But work on Emacs-20 so obviously counter productive to me that
> I suspect I just don't understand your motivations enough to
> give you a good response,

I'm sorry, perhaps I should have explained a bit more at
first.. desire to avoid a long-winded email has led to 3
medium-winded ones.  ;)

http://emacs-on-aqua.sf.net is a project to resurrect the old
NeXTstep port of Emacs, that has actually been maintained to some
extent over the years, until the point where it was based on
Emacs 20.7 and partially working on OS X.  (The Cocoa APIs are
based on OpenStep, the successor of NeXTstep).  We are interested
in getting this running well on both OS X and GNUstep, an
open-source implementation of OpenStep, and in bringing it up to
be based on the latest Emacs.

Rather than trying to do both of these at once, we decided to
bring the port up to date first on Emacs 20.7, since the code has
gotten a little rusty over the years.  This has been going well,
but one of the remaining tasks is 2-byte font rendering, which
led to my query.  We think we can handle it as long as we deliver
UTF-8 (or possibly plain unicode) to our renderer.  But we need
to try to be sure, and then will come the task of getting
fontsets working..

So, in our code we have a function ns_dumpglyphs() which plays
the role of dumplglyphs() in xterm.c: an array of GLYPHS is
received, the character info is extracted using
GLYPH_FAST_CHAR(), along with other face-related info, and the
text is rendered.  In our case, we need to convert the result of
GLYPH_FAST_CHAR() into UTF-8 or unicode.