[jsrjenkins]

The best I've found is emacs picture-mode.

https://www.gnu.org/software/emacs/manual/html_node/emacs/Ba...

Here is a good summary:

http://ergoemacs.org/emacs/emacs_ascii_diagram.html

[arminiusreturns]

I love how after all these years I can still find out random new things about emacs I didn't know. It's a treasure trove of capabilities.