@JeffTalbot Thanks for sharing this development effort. I've already been studying it and developing workflows around it. Like Gael, I'm interested in using my laser for the cutting (no worrying about separating the pieces)....but there is the problem that Gael mentioned which might come into play and then the problem of having duplicate segments. The latter being that all puzzle pieces have 4 sides and where those sides overlap with the adjacent piece, the laser will run twice through that curved segment. Not only does this take much longer, but you will likely get scorching or other detrimental artifacts.
So, the ideal situation WOULD be something like Gael mentioned where we could generate continuous paths composed of b-spline curves in the vertical and horizontal "grid" locations and then do an outer box cutout at the end. I am quite versed in all the web tech, so I'm in the process of going down this path. Eventually, I'd like to refactor this (with the above changes) as a CorelDraw (VBA macro) plugin...the idea being you select an imported bitmap, you click on the jigsaw macro toolbar icon, enter your grid size values (and maybe other options) and have a perfect laserable jigsaw template laid on top. The bitmap could be engraved as part of the job or just be used as a reference for a photo-quality print and substrate piece that's already on the laser bed and just needs the cut lines executed.
Anyway, the configurable and somewhat random shapes is hands down better than any of the other implementations (commercial OR free) that I've come across. Thanks again.