In better news, I've been playing with Web Assembly (wasm), and it's going fairly well so far (although I'm still only at the smoke test/toy code level).

I'm using clang to compile C to wasm, and then loading it into a web page. I give the wasm VM memory from JavaScript, ABC that means I can pass data between the two. Anything more complex than numbers needs to be flattened and re-inflated across the boundary, which is a chore (but not a hard one).

Current plan is to move some of the flocking maths over to wasm to see if it's any faster, although I'm distracted by GPU.js which calls into the GPU from JavaScript. For something like "find the distance between all the pairs of points", I think it's worth looking into (although really, I should grab some 2d space partitioning algorithm and use that instead).

(Really, I should find/build a metrics framework so I can measure how much time is spent doing various bits and pieces, so I can actually compare the different ways of doing things)