I implemented Hashlife for a different CA rule set earlier this year. Hashlife's data structure is a quad tree embedded in a hash table. Most Hashlife instance

I implemented Hashlife for a different CA rule set earlier this year. Hashlife's data structure is a quad tree embedded in a hash table. Most Hashlife instances only spend a few short moments simulating cellular automata at the "ground level"— the real work involves combining the future of the children of a quad tree node into the future of the node. That might be optimizable, but it feels extremely application-specific. Edit: shameless, shameless plug: https://rezmason.github.io/wireworld-player/?engine=macrocell https://rezmason.github.io/wireworld-player/?engine=macrocel...