macOS

Tallow builds and runs on Macs with Apple silicon (M1 and later), macOS 12 or newer. It draws with Metal, which every such Mac has. A Mac builds macOS games and web games; Linux and Windows games are built on Linux (see docs/windows.md).

Setting up, once

Tools: the Xcode command line tools (xcode-select --install), and from Homebrew brew install cmake ninja llvm@22 python@3.12.

The Beef compiler, built from source (the same commit as .github/workflows/macos.yml‘s BEEF_COMMIT):

git clone https://github.com/beefytech/Beef ~/beef
cd ~/beef/bin && PATH="$(brew --prefix llvm@22)/bin:$PATH" ./build.sh
export PATH="$HOME/beef/IDE/dist:$PATH"     # BeefBuild

The engine’s native libraries (bgfx for Metal, SDL3, Jolt, ENet, Opus…), from the engine’s folder:

python3 tools/patch_textedit.py
cmake -S native -B build/native -G Ninja -DCMAKE_BUILD_TYPE=Release -DCMAKE_OSX_DEPLOYMENT_TARGET=12.0 \
  -DCMAKE_C_COMPILER=/usr/bin/clang -DCMAKE_CXX_COMPILER=/usr/bin/clang++
cmake --build build/native --target tallow_native bgfx bimg bimg_decode bx SDL3-static joltc Jolt enet shaderc

Link settings

A Beef project that uses Tallow needs its [Configs.Debug.macOS] and [Configs.Release.macOS] link settings: the engine’s native archives and the system frameworks SDL and Metal use. python3 tools/macos_link.py --write path/to/BeefProj.toml adds them (for any number of projects), with the archives named from $(WorkspaceDir) so the file works on any machine. The engine’s own projects, the Launcher, the Tests and the Sandbox already have them.

Building a game for macOS

File > Build… in the editor on a Mac: Game, macOS and a folder. Or:

python3 tools/build_player.py /path/to/project --platform macos --output /path/to/folder

The folder holds the game’s program, its assets, the Metal shaders and the licences: copy it to another Mac and run the program. A Steam game wants libsteam_api.dylib from the Steamworks SDK beside the project, as on Linux.

The program is not signed. A Mac that downloads it marks it as from the internet and refuses to open it; the player opens it once with right-click > Open, or runs xattr -dr com.apple.quarantine <folder>. Signing and notarising need an Apple Developer account and are not done by Tallow.

File > Build… > Editor packages Tallow itself for macOS (tools/package_engine.py --platform macos).

Networking

Nothing changes: a Mac plays with and against Linux and Windows machines, as a client, a host or a dedicated server, over the same protocol. Physics runs with Jolt’s cross-platform determinism on every system, so client-side physics prediction behaves the same on a Mac (Apple silicon is ARM; Jolt is built to give the same results there as on x64).

Limits

• Script reload while playing (docs/script-hot-reload.md) is for Linux and Windows; on a Mac a script change needs Stop and Play.
• Built games are a plain folder with the program, not an .app bundle, and are not signed.
• The anti-cheat guard sees debuggers and injected libraries on macOS but cannot close the game’s memory to other programs as it does on Linux.
• The Tallow Hub has no macOS build yet.
• Intel Macs are not built for.

Tests