Spiral and other coordinate systems are on my list of things to add to the page. In addition to the Paul Bourke page, I have these bookmarked:

- https://gamedev.stackexchange.com/questions/71785/converting...

- https://tex.stackexchange.com/questions/275490/is-there-an-e...

- https://github.com/cooscoos/spiral_cube

- https://web.archive.org/web/20160309172431/http://www.pyxisi...

- https://www.sciencedirect.com/science/article/pii/0166218X92...

- https://thoughtstreams.io/jtauber/hex-map-addressing/

- http://tzaphiriron.sidemoon.net/static/hex/hex.html

- https://tilde.zone/@misterdave/109736460410840020

There's so much more to add to the page, and I keep adding over time. Thanks for the link to the hex-spiral crate; I'll add it to my bookmarks.