benbreen/recoilengine-applesilicon

RecoilEngine-AppleSilicon is an unofficial native macOS build of the Recoil game engine, the software behind the real time strategy game Beyond All Reason. Before this project, Mac users could only run the game through emulation layers like Rosetta or a virtual machine. This port lets it run directly on Apple Silicon Macs, using Apple's own graphics system, Metal, instead of relying on translation layers. The main technical challenge this project solves is that Beyond All Reason requires every player's computer to compute the exact same simulation results, down to the smallest rounding detail, so that everyone stays in sync during a multiplayer match. Apple's math libraries and the way its processors round numbers differ slightly from the Windows and Linux computers most players use, which could cause a Mac player's game to quietly drift out of sync with everyone else. The project fixes this by building in a matching math library, correcting how numbers convert between formats, and disabling a compiler optimization that could introduce tiny rounding differences, then testing the result against real matches to confirm the outputs match exactly. A large part of the macOS specific code and these fixes were written with the help of an AI coding assistant called Claude, working under the direction of the project's maintainer. The repository also builds on earlier community work that first got the engine running on Apple hardware. Downloads are provided on the project's releases page in two forms: a version for players that includes a launcher to download and update Beyond All Reason itself, and a plain version of just the engine for other developers or communities who build their own tools on top of it. The project only distributes the engine itself, which is licensed under GPL 2.0. The actual game content, meaning the units, art, and maps, is downloaded separately from the official Beyond All Reason servers and is not hosted or reviewed by this project. This is an independent, unofficial project not affiliated with the official Recoil or Beyond All Reason teams, so any issues with this specific Mac port should be reported to this repository, not to them.