Re: Customizing the fringe bitmaps

[Richard Stallman]

    One option is to load the bitmap from a (pbm) file.

    Another option would be to let the user draw the bitmap like this:

    (set-fringe-bitmap 'overlay-arrow 
                       '("*        "
                         "***      "
                         "*****    "
                         "*******  "
                         "*******  "
                         "*****    "
                         "***      "
                         "*        "))

How about combining the two ideas: use PBM (or one of the other
standard image formats), and provide a function to create such an
image inside Emacs using ASCII art as input.