new font-backend mechanism

[Kenichi Handa <handa@m17n.org>]

In article <E1FVTER-000815-00@etlken>, Kenichi Handa <handa@m17n.org> writes:

> Actually, after reading codes of XFT branch, I started to
> design a new font handling mechanism.  The basic plan is to
> use multiple font-backends drivers (xcore, xft, windows,
> bdf, atm, etc).  The main motivation for this rewriting is
> that the current XFT code in the branch is very difficult to
> utilize fontconfig's help for font selection, and to drive
> OTF fonts.  And also, I want to clean up the current fairly
> complicated font related codes (including many HAVE_XFT
> conditionals, many XLFD parsing code, etc).

> But, as there are many other works to be done, the progress
> for the above code is slow.  Please don't expect a quick
> response on this matter.  Anyway, here's the current font.h
> file (not yet fully considered) with which you may get a
> feeling of the design.

I've just committed changes for this font-backend mechanism
in emacs-unicode-2 branch.  As I added two tags before and
after the commit, you can see what are changed by:

% cvs diff -Nu -r unicode-pre-font-backend -r unicode-post-font-backend

The reason I dared not make a new branch is that the new
codes don't affect the current behavior of emacs-unicode
unless you configure with "--enable-font-backend" and run
Emacs with the same arg.  README.unicode contains some more
information about the changes.

We still need many more works to make using of font-backend
the default.  But, before going ahead, I'd like to ask
people working on Windows and Mac porting to check if the
current mechanism (APIs of font-driver) is sufficient for
native fonts support.

I think it is better to use emacs-unicode@gnu.org (not
emacs-devel@gnu.org) for the further discussion on this
matter to avoid disturbing the works for the official
realease.  So, people who are interested in it please join
emacs-unicode mailing list.  For that, as far as I remember,
Eli <eliz@gnu.org> can handle a request of subscribing.

Eli, is it right?

---
Kenichi Handa
handa@m17n.org