d9mt — D3D9 on Metal for Apple Silicon

A from-scratch Direct3D 9 → Metal driver for Wine/CrossOver on Apple Silicon. No Vulkan, no MoltenVK — D3D9 calls are translated to Metal directly.

It pairs DXVK's battle-tested D3D9 front-end (D3D9 → SPIR-V → MSL) with a custom Metal backend that talks to the GPU through DXMT's winemetal bridge.

Tested with exactly one game so far. It has only been run against a single D3D9 title (GTA IV) — no other DirectX 9 game has been tried yet, so expect unimplemented paths on anything else.

YourGame.exe  (32-bit Windows PE, runs under Rosetta 2)
   │  loads
   ▼
d3d9.dll      ← THIS PROJECT (mingw PE):  DXVK D3D9 front-end + d9mt Metal backend
   │            DXSO bytecode → SPIR-V (DXVK) → MSL (spirv-cross) → metallib
   ▼
winemetal.dll / .so   (DXMT prebuilt, Wine builtin)  ──►  Metal  ──►  CAMetalLayer
   ▲
d9mtmetal.so  (our native arm64 Wine unixlib: PSO creation, MSL→metallib compile, shader disk cache)

• Playable. A real, draw-call-heavy D3D9 title renders and runs end-to-end on an M1 Max at roughly 50-90 fps depending on how many draws a scene issues.
• Shader disk cache: each shader compiles once ever (out-of-process via the Metal toolchain), is cached to disk, and reloads instantly — no compile stutter, fast warm boot.
• Performance work landed: async pipeline compilation, command batching, buffer suballocation, residency dedup. Frame pacing is clean.
• This is research-grade software for a single platform (Apple Silicon + CrossOver). Expect rough edges on untested games.

• Apple Silicon Mac (M1/M2/M3…), macOS 14+.
• CrossOver (tested on CrossOver 26, which bundles DXMT/winemetal). A plain Wine prefix with the DXMT winemetal builtin also works.
• Xcode Command Line Tools + the Metal toolchain — xcrun metal must resolve. The native unixlib links Metal/Foundation, and the shader cache shells out to metal to compile MSL → metallib. Check: xcrun --sdk macosx --find metal.
• mingw-w64 (both i686-w64-mingw32 and x86_64-w64-mingw32) — e.g. brew install mingw-w64.
• glslang (brew install glslang), python3, and a working sqlite3 (system-provided on macOS).

Three steps, from the repo root. DXVK and spirv-cross are vendored in vendor/ — nothing to fetch for the front-end.

# 1. Pull DXMT's winemetal binaries into prebuilt/ (needed to link against).
bash scripts/fetch-winemetal.sh

# 2. Build the native companion unixlib (d9mtmetal.so + PE shims) and install
#    it into CrossOver. Set BOTTLE to your game's bottle name.
BOTTLE="My Game" bash tools/build-d9mtmetal.sh

# 3. Build the driver itself -> build/d3d9fe.dll
bash scripts/build-dxvkfe.sh

For a production build — -O3, asserts stripped, and the in-engine profiler + file logging compiled out (zero hot-path instrumentation):

RELEASE=1 bash scripts/build-dxvkfe.sh

It uses a separate object cache (build/dxvkfe-obj-release), so it won't clash with the default dev build.

1. Deploy the driver as d3d9.dll into your game's folder:

   GAME_DIR="$HOME/Library/Application Support/CrossOver/Bottles/My Game/drive_c/.../YourGame"
   cp build/d3d9fe.dll "$GAME_DIR/d3d9.dll"

2. Launch with d3d9 overridden to the native (our) DLL:

   CX="/Applications/CrossOver.app/Contents/SharedSupport/CrossOver"
   WINEDLLOVERRIDES="d3d9=n" "$CX/bin/wine" --bottle "My Game" \
     start /unix "$GAME_DIR/YourGame.exe"

Step 2 of the build already installed winemetal/d9mtmetal into the bottle and registered them as Wine builtins. If a game ships its own d3d9.dll, your copy in the game folder takes precedence with the override above.

All performance features are on by default; set to 0 to disable for A/B.

Example — run with the cache off to measure cold compile: D9MT_METALLIB_CACHE=0 wine ...

• SIP can stay enabled; the driver itself doesn't require disabling it.

• The DXVK D3D9 front-end (vendored) turns the game's DXSO shader bytecode into SPIR-V and tracks all D3D9 state; spirv-cross turns SPIR-V into MSL.
• The d9mt backend (src/d3d9fe/) replaces DXVK's Vulkan layer: it builds Metal render pipelines, argument buffers, and command streams, and submits them through winemetal.
• d9mtmetal (src/d9mtmetal/) is our small native Wine unixlib for the two things winemetal doesn't expose: pipeline-state creation with a vertex descriptor, and the MSL→metallib compile + on-disk shader cache.
• See docs/ for the architecture notes (Metal backend, shader cache design).

• DXVK — the D3D9 front-end (DXSO → SPIR-V) and spirv-cross plumbing, vendored under vendor/.
• DXMT — the winemetal bridge that carries Metal calls across the Wine wow64 boundary.
• spirv-cross — SPIR-V → MSL.

See the licenses of the vendored components (DXVK, spirv-cross) under vendor/. d9mt's own code follows suit.