Re: [emacs-bidi] status? news?

[Eli Zaretskii]

On 18 Jan 2001, Matan Ninio wrote:

> But can you clue us in as to what files to look into?

dispnew.[ch], dispextern.h and xdisp.c are the main files, IIRC.

This is only a single layer of the display engine, the one which produces 
the glyph matrices and decides which parts of the screen need to be 
redrawn.  The code which actually draws the glyphs is elsewhere (xterm.c 
for the X display, term.c for the tty display, etc.).  But the glyph 
matrices generation is the main place where the logical to visual 
conversion should take place, so this is the right place to start.  You 
can ignore the actual screen drawing for the moment.

> A fast glimpse at dispnew.[hc] shows that the code is highly documented
> (the h file is about 40% comments), but I did not see a overview section
> (may have missed it).

The introduction you are looking for is in xdisp.c.  dispextern.h also 
explaines quite a bit about the main data structures.

> Is there some other place one can look in for
> comments, explanations and the such?  overlays, for example, where do I
> find out what they are?

The internals are not documented, unfortunately.  You will have to read 
the code and its comments, look in the relevant sections of the ELisp 
manual (the version which includes Emacs 21 features is already on 
ftp.gnu.org, in the gnu/emacs directory), and ask here what you cannot 
figure out.

For text properties (I assume that you meant them, not overlays), for 
example, see intervals.[ch] and textprop.c.