A Direct3D 9 to Metal translation layer for running Fallout: New Vegas on macOS via Wine. A Wine-side d3d9.dll captures D3D9 state and bulk uploads, a shared backend bridge serializes the frame into IPC, and a native Metal viewer replays the frame on Apple GPUs.
As of March 5, 2026:
- Main menu rendering is stable.
- In-game 3D rendering is now working in the Metal viewer.
- Offscreen HDR render targets and
StretchRectreplay are working well enough for the world scene to reach the drawable. - The frame is still visibly corrupted: large white/light-blue planar bands, exploding billboard or foliage geometry, and incomplete composite or post-process passes remain.
- The translated shader path is now the primary render path, with per-hash shader and PSO failure artifacts written into the session output directory.
FalloutNV.exe (i686 / Wine)
|
v
+------------------------------------+
| d3d9.dll (PE32, MinGW) |
| Implements IDirect3DDevice9 |
| Captures draws, clears, blits, |
| shaders, textures, and state |
+----------------+-------------------+
| packets + 3 x 256MB upload refs
v
+------------------------------------+
| Backend Bridge (compiled twice) |
| PE32 inside the DLL, ARM64 inside |
| libdx9mt_unixlib.dylib |
| Validates packets and assembles |
| shared-memory IPC on Present() |
+----------------+-------------------+
| 256MB IPC file
v
+------------------------------------+
| Metal Viewer (native ARM64 macOS) |
| Replays draws and StretchRect |
| Translates D3D9 bytecode to MSL |
| Renders via Metal into NSWindow |
+------------------------------------+
The frontend DLL replaces the system d3d9.dll inside a Wine prefix. Each indexed draw snapshots the device state into a packet and uploads bulk geometry, constants, shader bytecode, declarations, and texture payloads into a rotating arena. The backend serializes the frame into /tmp/dx9mt_metal_frame.bin, and the standalone Metal viewer snapshots and replays that frame.
- Shader translation covers D3D9 shader model 1.x through 3.0 bytecode and caches compiled Metal functions by bytecode hash.
- Viewer replay covers indexed draws,
Clear, offscreen render targets,StretchRect, depth and stencil state, blending, scissor, cull, fog parameters, and up to 8 texture stages. - Supported sampled or render-target formats include DXT1, DXT3, DXT5, A8R8G8B8, X8R8G8B8, A8, R32F, and A16B16G16R16F.
- Render-target-to-texture linkage is tracked explicitly, so later passes can sample earlier offscreen output.
- Diagnostics emit
dx9mt_runtime.log,dx9mt_viewer.log,dx9mt_shader_fail_*.txt,dx9mt_pso_fail_*.txt, and frame dumps indx9mt-output/session-*.
- Scene composition is not yet correct; the current gameplay image still contains large planar corruption across the screen.
- Some billboard, alpha-tested, or foliage-heavy draws are still exploding into spikes or dense point clouds.
- Not every translated VS/PS pair produces a valid Metal pipeline yet.
- Some draws still depend on textures that arrive with metadata but no upload payload, relying on cache or render-target override state the viewer may not have yet.
- Heavy frames can still hit upload-arena pressure or bulk-range validation failures.
Requires macOS (ARM64), Xcode command-line tools, and an i686-w64-mingw32-gcc cross-compiler.
# Build the DLL, backend dylib, viewer, and native tests
make -C dx9mt
# Run native contract tests
make test
# Build, install into the Wine prefix, and launch FNV plus the viewer
make run| Artifact | Arch | Description |
|---|---|---|
build/d3d9.dll |
PE32 (i686) | D3D9 frontend injected into Wine |
build/libdx9mt_unixlib.dylib |
ARM64 | Backend bridge library |
build/dx9mt_metal_viewer |
ARM64 | Standalone Metal frame replay app |
docs/architecture.md: current packet, IPC, and viewer architecturedocs/rendering_findings.md: current visual state and active bug bucketsdocs/insights.md: implementation gotchas and debugging notesdx9mt/README.md: inner build notes for the source tree
MIT License