"same-runtime" — identical results for the same build on the same JS
engine, OS, and hardware. The engine's initial target
(DEFAULT_DETERMINISM_LEVEL, Appendix A).
"same-platform" — additionally stable across runs and engine minor
versions on one platform, which requires avoiding JS Math transcendentals
in simulation paths.
"cross-platform" — additionally stable across OS and hardware;
effectively the whole simulation path must run in deterministic
WebAssembly or software floating point.
The tiers are ordered by strength — see DETERMINISM_LEVELS, whose
index is that order. Adapters declare the tier they can actually achieve in
PhysicsCapabilities.determinism (§37); a world may not ask for more than
its adapter declares.
Declared reproducibility of a simulation (§33).
"none"— no reproducibility is claimed."same-runtime"— identical results for the same build on the same JS engine, OS, and hardware. The engine's initial target (DEFAULT_DETERMINISM_LEVEL, Appendix A)."same-platform"— additionally stable across runs and engine minor versions on one platform, which requires avoiding JSMathtranscendentals in simulation paths."cross-platform"— additionally stable across OS and hardware; effectively the whole simulation path must run in deterministic WebAssembly or software floating point.The tiers are ordered by strength — see DETERMINISM_LEVELS, whose index is that order. Adapters declare the tier they can actually achieve in
PhysicsCapabilities.determinism(§37); a world may not ask for more than its adapter declares.