Inspired by this post two years ago, I wrote a more comprehensive version: https://chidiwilliams.com/post/quadtrees/ https://chidiwilliams.com/post/quadtrees/.

Inspired by this post two years ago, I wrote a more comprehensive version: https://chidiwilliams.com/post/quadtrees/ https://chidiwilliams.com/post/quadtrees/. Also showed how quadtrees could be used for compression.