Re: Allowing point to be outside the window?

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

> This is sometimes set for Emacs itself, regardless of the user
> commands.  So all such uses should be audited.

Most of the uses seem fine to me (mostly in the scrolling commands,
which I've already modified as appropriate, and also when the cursor is
obscured and make-cursor-line-fully-visible is non-nil), but I have one
question about the following code:

      /* We used to issue a CHECK_MARGINS argument to try_window here,
         but this causes scrolling to fail when point begins inside
         the scroll margin (bug#148) -- cyd  */
      clear_glyph_matrix (w->desired_matrix);
      if (!try_window (window, startp, 0))
        {
          w->force_start = true;
          clear_glyph_matrix (w->desired_matrix);
          goto need_larger_matrices;
        }

Why does it have to force start?  Doesn't need_larger_matrices take care
of resizing the matrix when, for instance, fonts change?

Thanks.

> Yes.  I'm saying that if point is allowed to be outside of the window
> during some redisplay cycle, we'd need a different criteria for when
> and how to change w->start.

Why is that so (for the "how to change w->start" part)?  Making point
display in the center of the screen in that case will be intuitive for
most users.