Re: Stylus drawing input?

[Eli Zaretskii]

> From: Dov Grobgeld <dov.grobgeld@gmail.com>
> Date: Tue, 24 Jan 2023 10:03:02 +0200
> Cc: emacs-devel@gnu.org, tomas@tuxteam.de
> 
> Thanks. I need some guidance on how feasible the following is and how
> I would go about doing it.
> 
> 1. How do I draw vector graphics object in an emacs buffer. I.e.
> line-to, move-to, close-path, fill etc. Do I need to generate the
> pixels on my own (can be done e.g. with the agg library or with
> libcairo) and then place the image as on overlay (how?), or is there
> higher lever interface? Is it accessible from elisp or from C?
> 2. How can I trace the x,y input coordinates of mouse movement. E.g.
> I'd like to run a command to enter capture mode, and then catch
> subsequent motion events of the mouse, until the mouse button is
> raised. The resulting object should be a list of motion coordinates.
> 3. How would I do the same for a stylus while catching additional pressure 
> data?
> 4. Given some vector graphics objects drawn on the screen, how would I
> do mouse hit detection, so that doing a mouse click on the object,
> returns the object id? (This I can do "offline" though, by drawing a
> "label image" of the buffer contents on mouse press end then finding
> the label of the object under the mouse.)

Does the svg.el library help with some of the above?