Re: How to Display a Zero Height Line

[Psionic K <psionik@positron.solutions>]

> I think currently, you won't be able to get down to actual zero *except*
> by making that line `invisible`.

It is appropriate to merely get "pretty close" to zero, a pixel or so.
In animation, as long as the final height is quite small, it appears
to smoothly vanish on the final frame.

Regarding Eli's reply:
> What do you mean by "extending the background of :inverse-video
> background" of a line?  Can you show some simple Lisp which produces
> this effect on display?

    (let ((buffer (get-buffer-create "testorito")))
      (set-buffer buffer)
      (erase-buffer)
      (insert "* ")
      (insert (propertize  "TODO" 'face '(:inverse-video t)))
      (insert " Org Modern Uses Inverse Video")
      (insert "\n")
      (insert "* ")
      (insert (propertize  "TODO" 'face '(:inverse-video t :foreground
"#ff2222")))
      (insert " To Draw Fancy Todos")
      (setq-local p (point-max))
      (insert "\n")
      (setq-local o (make-overlay p (1+ p)))
      (overlay-put o 'line-height 4.0)
      (switch-to-buffer buffer))

This example re-creates the situation that exists in Dslide.  I need
to separate the two lines by some floating point multiple of lines in
order to "slide in" to a vanishing degree of separation between two
lines of content.  I use the same technique between list items and
sub-headings.  All text that has a background exhibits the behavior,
not just `:inverse-video`.