Re: SVG hack for display engine

[Alan Third <alan@idiocy.org>]

On Fri, Nov 19, 2021 at 07:02:20AM +0530, Anand Tamariya wrote:
> > > - svg-render (svg x y width height)
> > > svg is a Lisp DOM object as returned by (dom-node). This should use
> > librsvg to generate a bitmap image of
> > > svg of size (width x height) and superimpose it at position (x, y) on
> > the current bitmap being displayed by
> > > Emacs.
> > *The current image API takes either a filename or XML string for SVG. This
> > can be avoided if svg is a > Lisp DOM.* Edit: (dom-node) is defined in
> > dom.el .
> >
> Can you visualize the amount of string serialization, deserialization and
> SVG parsing happening in a draw or move operation with live feedback? Do
> you see it performing well for even a moderately sized SVG?
> 
> Without direct SVG support in the display engine ie. a way for a developer
> to tell the display engine to use a particular SVG  in a DOM form during
> it's normal display cycle, any such implementation will remain a hack - it
> works but it could be much better.

I'm curious. I can't see any functionality in librsvg for loading an
SVG DOM directly without doing a round-trip into a string. Am I
missing something?

Does this idea rely on using some Cairo functionality?
-- 
Alan Third