Old school D3 from simpler times

This animation shows how successively adding points to a quadtree changes its structure. Each red dot represents a point; each gray rectangle represents a leaf node in the quadtree; black lines separate internal nodes. Assuming no coincident points, each gray leaf contains exactly one point. (If some points are coincident, the leaf node contains a linked list of the coincident points.)

https://d3js.org/d3-timer.v0.4.min.js

https://d3js.org/d3-random.v0.2.min.js