Complex 2D rigid-body simulations involving thousands of dynamic colliding bodies push JavaScript V8 execution to its limits. Compiling the open-source **Rapier2D** physics engine from Rust to **WebAssembly (WASM)** provides SIMD-vectorized, deterministic physics execution with near-native CPU speeds.
1. Zero-Copy Shared ArrayBuffer Architecture
Rather than serializing physics coordinates across the WASM boundary using expensive JSON bridges, the JavaScript rendering loop reads body coordinates directly from WebAssembly's linear memory buffer via a `Float32Array` view.
