Unexpected Gotchas in Making a Game Deterministic
a year ago
- #programming
- #game-development
- #determinism
- Deterministic programming requires careful seeding of random number generators, handling of multithreading, and floating-point computations.
- Less common pitfalls include differences in compilers, compiler options, standard library implementations, and architectures.
- Random number generation issues arise from `uint_fast32_t` usage in `std::mt19937`, which varies by architecture (32-bit vs. 64-bit).
- Standard library distributions (e.g., `std::uniform_int_distribution`) can vary across implementations, leading to non-deterministic behavior.
- Sorting and parameter evaluation order can produce different results across platforms (e.g., Linux vs. Windows).
- Memory usage limits are non-deterministic due to varying pointer sizes, alignment requirements, and STL implementations.
- Deterministic memory limitation enforcement requires higher-level abstractions than just allocation size.
- References to external resources on deterministic floating-point calculations and game determinism are provided.