I'm trying to create a hand-writing animation effect for video presentations. The standard open tool trick for this is to draw SVG paths and animate the dash pattern from 0 to the end of the path.
This works well for standard paths, but if I convert naively a letter, or a mathematical symbol, to SVG paths, they come out as filled outlines, and drawing the path looks unnatural at best.
For standard text, there are fonts such as Hershey that have just the central stroke, which should work fine, but with math fonts I have not had any luck finding one that LaTeX followed by svg conversion would produce single strokes (and ideally in a natural calligraphic drawing order).
Of course this all is quite reminiscent of Metafont itself — pick up a pen, move there, etc. Makes me thin that the most elegant solution would be a Metafont/post-created font that only has single strokes (no filling) and has all the kerning etc. bells-and-whistles for use in TeX.
I've looked a bit into the Punk font, http://metapolator.com, and the like but having no experience with Metapost it's unclear to me how difficult the task would be. In essence, I'd like to make a dumbed-down copy of a standard Metafont, such that every glyph is a skeleton rather than a filled outline.
I'm not too worried about the poor aesthetics as typically the final SVG would be drawn with a fairly thick pen, again with the intention to mimic chalk/whiteboard pen handwriting — no fine serifs etc. there...
PS: One possible variation of this idea is to use the skeleton font as SVG mask to uncover a better-looking font behind it — the single strokes simply define the order of unveiling what's behind.
Edit: simplified sub-problem
Let's assume I have created all the glyphs I need, both text and maths, e.g. tracing over a comprehensive list such as that of Stix glyphs, imported it into FontForge and created a font out of it (I'm not sure how some aspects work, but sounds doable). How would I then enable it for LaTeX (/xe/lua, ...), such that the boxes containing those strokes are correctly positioned?
Addendum:
After even more googling I found a couple of relevant links:
How to create non-outlined SVG files from LaTeX formulae
https://github.com/KaTeX/katex-fonts/
It sounds like standard font formats don't like single-line descriptions, so the question become: how do I use a SVG font with a TeX-like box-positioning engine? Might be that Katex/Mathjax is the easier route here (with obvious limitations, but I'm interested in simple-enough output).
Edit (2021): after further searching and experimenting (dvisvgm, notably) I believe I've found a promising strategy with Mathjax, which can produce SVG output from given equations (the coverage is quite substantial). SVG paths are stored in Mathjax internal routines but in principle one can replace them with single-stroke alternatives. Now all that's left for me to do is draw them ;) (or, ideally, convince Metapost to do it for me?)
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