The nphysics physics simulation library for gamedev used this approach of using fixed point math whenever cross-platform determinism was wanted, with CORDIC. Nphysics however was deprecated.
The newer Rapier library (which is a rewrite of the nphysics) instead relies on the guarantees of IEEE-754 2008 to provide cross-platform determinism, which means that it doesn't work with old platforms, but it is deterministic across modern platforms, including wasm. And yes, you can't rely on the transcedental routines provided by each platform (like sine, cosine, etc), those need to be implemented in a way to work the same everywhere. But, this is possible if avoid running on non-compliant platforms.
The newer Rapier library (which is a rewrite of the nphysics) instead relies on the guarantees of IEEE-754 2008 to provide cross-platform determinism, which means that it doesn't work with old platforms, but it is deterministic across modern platforms, including wasm. And yes, you can't rely on the transcedental routines provided by each platform (like sine, cosine, etc), those need to be implemented in a way to work the same everywhere. But, this is possible if avoid running on non-compliant platforms.
https://www.rustsim.org/blog/2020/06/01/this-month-in-rustsi...
https://rapier.rs/docs/user_guides/rust/determinism/