Stylus drawing input?

[Dov Grobgeld <dov.grobgeld@gmail.com>]

Hello,

I wonder if anyone has ever worked on stylus (or mouse actually)
drawing input for emacs, which stores a "path" [*] of the stylus input
events?

Here are some possible use cases for such support:

In PDF-Mode there is an annotation option that allows attaching text
to various points in the document. It would be a nice addition to be
able to scribble with a stylus on top of the document and leaving
behind a "path" annotation as well.

Another use for such a mode would be for the android port, where we
may send the path to a path-to-text algorithm, for stylus text input.

When giving a presentation, it is often quicker to scribble on top of
the slides to illustrate a point, than it is to edit the source text
of the presentation.

Thanks!

[1] A path is here defined as a sequence of moveto xy, lineto xy,
(curveto(?), closepath) commands. Possibly with with additional vertex
attributes like time, pressure, tilt, etc.