>
> I'm not sure I understand the question.  Are you saying that if you ignore
> the line overflow, termination of a line, etc., you can write code that
> does
> display characters column-wise?


I thought that displaying line row wise is the "base" of the display_line
function with code for
line truncation, overflow, bidi etc added on top of it in "if" blocks, so
if I could just get the base to work (i.e. displaying lines in a column)
then I could work on the the finer details.
Am I wrong?

In any case, it is hard to discuss this without seeing the code which
> doesn't work.  Is the code you wrote available anywhere for review?
>

Unfortunately it is no longer available.
One line which I remember causing a problem though was line 24500 in
src/xdisp.c
row->y = it->current_y;
if I changed it to: row->x = it->current_x; Emacs no longer displays
characters.


On Sun, Nov 20, 2022 at 5:13 PM Eli Zaretskii <eliz@gnu.org> wrote:

> > From: समीर सिंह Sameer Singh <lumarzeli30@gmail.com>
> > Date: Sun, 20 Nov 2022 16:48:31 +0530
> > Cc: emacs-devel@gnu.org
> >
> > I tried writing a vertical version of the display_line function but
> could not get it to work. Emacs does not
> > display any character after these changes.
> > (maybe I should have also rewrote move_it_in_display_line_to?)
>
> I don't think move_it_in_display_line_to is relevant at this early stage of
> your work.
>
> > Therefore forgive me for asking again, if for now I just want to make
> the characters appear column wise
> > instead of row wise, disregarding line overflow, or termination of a
> line etc,
> > do I still have to look into the display_line function, because as I
> recall I had once removed most of the lines
> > of the display_line function and Emacs was still displaying lines fines.
>
> I'm not sure I understand the question.  Are you saying that if you ignore
> the line overflow, termination of a line, etc., you can write code that
> does
> display characters column-wise?
>
> In any case, it is hard to discuss this without seeing the code which
> doesn't work.  Is the code you wrote available anywhere for review?
>