Truchet tiles

https://github.com/nedbat/truchet/blob/main/Truchet.ipynb

Ned Batchelder's implementation of a scale-free tile system by Christopher Carlson

“Truchet tiles” originate with a treatise by Sebastien Truchet published in 1704, Mémoir sur les Combinaisons, in which Truchet investigates the kinds of patterns that can be made with a simple square tile divided diagonally, white on one side and black on the other. Cyril Stanley Smith popularized the idea in his 1987 paper, The tiling patterns of Sebastian Truchet and the topology of structural hierarchy. Toward the end of that paper, Smith introduces a tile that has become the most popular representative of the idea of Truchet tiles: