The article in question, https://www.redblobgames.com/articles/sdf-fonts/ is really neat as well, especially the interactive demonstrations
Thanks!
Valve originally devised this technique in 2007:
https://steamcdn-a.akamaihd.net/apps/valve/2007/SIGGRAPH2007...
I originally had that near the top but in one of the rewrites I moved the papers to the end — https://www.redblobgames.com/articles/sdf-fonts/#appendix
Oh thank-you for the reminder to check Amit's site again! (been following since the BBS and SolarRealms days...)