Re: [w32] display international HELLO

[Eli Zaretskii]

> From: "Richard Wordingham" <address@hidden>
> Date: Fri, 9 Nov 2007 08:37:42 -0000
> 
> > Is there any ways to display them?
> > Or should I use other fonts?

I guess some of the useful stuff you posted should find its way into
PROBLEMS.  So please keep on with posting any findings you will
discover as result of this discussion.  Thanks!

> 2. My first discovery with Lao was that just selecting a font (Code2000) 
> that supported Lao was not enough.  It would not normally display Lao 
> characters (in the Lao charset), until I discovered that a trick such as
> 
> (set-fontset-font "fontset-myfont" 'lao '("Code2000" . "iso10646-1"))
> 
> suddenly made the Lao text displayable.  How does this work?  I have studied 
> the code of xdisp.c and its supporting functions, but I cannot find where 
> Emacs character codes are converted to Unicode.

I think you need to look in w32term.c as well.  For example, the
function w32_encode_char there seems to be a good place to start.

> I did notice that if I pasted Lao in from an MS application, Emacs
> would accept them as Unicode characters and they would be displayed
> properly if I selected an appropriate font.

Yes, Emacs on Windows uses Unicode for working with the clipboard
whenever possible.

> 4. When I explicitly specify that a buffer is to be saved in UTF-8 (or one 
> of its variants), the Lao input method suddenly switches from generating Lao 
> characters in the Lao charset to generating Lao characters in the 
> mule-unicode-0100-24ff charset.  How is this effect achieved?

That's because UTF-8 is supported only for mule-unicode-0100-24ff, so
decoding UTF-8 will _always_ produce Unicode characters.

> Characters already stored in the Lao charset remain in the Lao 
> charset in the buffer, as confirmed by C-x C-e (eval-last-sexp).

Yes.  This is because changing buffer's encoding does not change the
buffer contents in any way, it just tells Emacs how to encode the
buffer text when the time comes to write it to disk.  At that time, if
there are any characters in the buffer that cannot be encoded in the
encoding you specified, Emacs will complain and show you those files,
so that you could choose a different encoding.

> Bizarrely, selecting UTF-16 as the encoding for saving the buffer does not 
> change the charset used by the Lao charset.

Probably a bug of some sort.

> 6. Latin ligaturing does not work.

Yes, Emacs currently does not support this feature.