MetalHorizon – FH6 Mac Launcher

Run your own Xbox / Microsoft Store copy of Forza Horizon 6 on an Apple Silicon Mac AND STEAM! Blackwell Engine (Wine) + xodus + Apple's D3DMetal, open source, no CrossOver, no DRM bypass.

MetalHorizon (latest prototype): unzip, move MetalHorizon to Applications, then right-click it → Open the first time (it is not notarized yet).

The app does the rest by itself: it installs Blackwell Engine and Apple's D3DMetal (after you accept Apple's licence), you sign in with your Microsoft account on Microsoft's own page, click Download from Xbox, then Play. No CrossOver, nothing to download by hand.

Prototype. Tested on one Mac so far (M5 Pro, macOS 27). Known: stutter, black near foliage. This is for the Xbox / Microsoft Store edition (MSIXVC). If you own the Steam edition, The steam version just got released!

Unofficial. Not affiliated with or endorsed by Microsoft, Xbox, Playground Games, Apple, CodeWeavers or NVIDIA. Forza Horizon and Xbox are trademarks of Microsoft. You need your own copy of the game on your Microsoft account.

Tested on one machine: MacBook Pro 16" M5 Pro (18-core CPU, 20-core GPU, 48 GB), macOS 27.0.1.

Known issue: leave the in-game ray tracing options alone; changing them has crashed the game (FHE11).

• The game's files are never modified or redistributed. The executable is not patched.
• The copy protection, the license check and the anti-cheat are not bypassed. The game accepts its own license. Every fix lives in the compatibility layer: Wine, the DirectX 12 shim, xodus. The protection even rejects a diagnostic change in Wine's PE ntdll.dll exception path (3 crashes in 3 starts), so that path stays stock.
• xodus decrypts the MSIXVC package with your own account's license, as the Xbox app does on Windows. The game files stay encrypted on disk.
• Your Microsoft password never goes through this project. You sign in on Microsoft's own page with a code; xodus-service keeps the account in the macOS Keychain.
• Like Highball's recipe, the game is shown an NVIDIA GPU ID (RTX 4070) so its hardware check (FH205/FH206) passes.
• Nothing from CrossOver.app is used. Apple's D3DMetal is downloaded by the app, unmodified, only after you accept Apple's licence (which allows it to be shared separately for non-commercial use).

This is unofficial software. Nobody can promise Microsoft will never act on an account used this way, especially online. Use it at your own risk.

• Apple Silicon Mac, macOS 27 or later. Memory use is high; only 48 GB has been tested so far.
• About 160 GB free, outside iCloud-synced folders (the Desktop is a bad place for the game).
• Forza Horizon 6, Xbox / Microsoft Store edition, on your Microsoft account. Game Pass is untested.
• That's all. The MetalHorizon app downloads Blackwell Engine and D3DMetal 4 by itself, then the game from the Xbox servers. No CrossOver, no manual download.

forzahorizon6.exe          (decrypted in memory by xodus, never written back)
  └─ Blackwell Engine      Wine 11 from CrossOver 26.3's LGPL sources + Ferestre + Highball + this repo's patches,
      │                    with its own GnuTLS, FreeType and MoltenVK (engine/)
      ├─ xgameruntime      Xbox layer: tokens from xodus-service, PlayFab cloud saves
      ├─ d3d12.dll shim    Highball's shim + this repo's shader fixes and inspector
      │   └─ D3DMetal 4    DirectX 12 → Metal (Apple's Game Porting Toolkit redist, unmodified)
      └─ Core Audio        surround mixed down for the Mac's speakers

Everything below is built on the Mac. Each script keeps a .bak of what it replaces and has --undo.

An experimental launch on Mullion (a DXMT fork) instead of D3DMetal is in tools/mac_launch_fh6_mullion.sh. No result yet.

What was found while fixing the graphics, 24–25 October 2026. Details and evidence: docs/PASSATION-IA.md (French).

Missing objects: 221 pipelines → 0. D3DMetal marked 221 pipelines as "no-op" and skipped every draw that used them.

1. SV_ShadingRate (148 pipelines). D3DMetal already reports no variable-rate shading (tier 0), but some pixel shaders still read SV_ShadingRate. Metal's converter turns it into an input the vertex shader never writes, and Metal refuses the pipeline. The shim relabels that input as SV_ViewportArrayIndex in the DXIL (Metal provides it; 0 means 1×1, the value without VRS). Trap: D3DMetal caches its translations on disk under the shader's HASH part, not its bytes, so the shim rewrites HASH too, or the broken translation comes back from the cache.
2. Dual-source blending without a color target (65 pipelines). Shadow passes of glass, water, ocean and dithered materials keep the material's SRC1 blend with no color target. D3DMetal then forces dual-source blending, which the converter refuses. The shim turns that unused blend off.
3. Skid marks (8 pipelines). Real dual-source blending, but the pixel shader writes three outputs and Metal wants exactly two. The same shader also serves a three-target decal pass, so only the dual-source pipelines get a replacement shader without the third output, built by tools/mac_shader_fixes.sh. A game update changes the shader hashes: the fix then stops applying, with no other effect.

Result in game (6 minutes with the inspector): 22,875 pipelines, 0 refused, 0 skipped.

Black near foliage: cause narrowed down, not fixed. The inspector (HB_TSSHIM_INSPECT=1) wraps draws in occlusion queries and replays them through invisible "twin" pipelines to see where pixels are lost. The near-foliage color pass uses an EQUAL depth test against a depth pre-pass drawn by a different vertex shader. On Metal the two depths do not match bit for bit, so EQUAL rejects the pixels: 569 of 2,521 measured draws produce pixels that the depth test then throws away. Environment and character skin pipelines show the same pattern. Turning every EQUAL into GREATER_EQUAL + bias breaks the full-screen passes that use EQUAL to sort pixels (grey blocks), so the fix has to target only the affected pipelines. Next step: measure which correction restores which pixels.

Crashes under investigation. A crash in Apple's AGX driver (libdispatch voucher read through gs:[0xe0]) while the map loads, seen so far only with the inspector on. Two threads using one freed XAsyncBlock (xgameruntime), now completed after the call returns, as Windows does. Crashes in the game's network session code during online play.

1. Frame pacing: find what the game does during a freeze (tools/mac_sample_hitch.sh), fix it in the compatibility layer.
2. Black foliage: a per-pipeline depth fix, chosen from measurements.
3. Crashes: map loading, online sessions.
4. A prebuilt engine without CrossOver: done, Blackwell Engine (engine/).
5. The MetalHorizon app installs everything by itself (done); next, signed and notarized.
6. Other Xbox-edition games people ask for (Forza Horizon 5 and 4).

Every build is free and public, the same day, for everyone. Sponsors fund the work, not access. Your support pays for an Apple Developer account (so macOS opens the app without warnings) and support its development, plus the time spent so I can try fixing stutter and graphics bugs. Thank you! ☕ Support it on Buy Me a Coffee (also the app's Support Me button); details in SPONSORS.md.

• docs/PASSATION-IA.md: full history, evidence, tools, open questions (French)
• docs/ANALYSE-FH6-STORE-MACOS.md: technical analysis of the Store edition (French)
• docs/DEVELOPPEMENT.md: developer notes and test commands (French)

On the author's setup, playing is one line: bash tools/jouer.sh.

• Highball and highball-engine, by Gauthier Piarrette (GPL-3.0): the DirectX 12 shim, Wine patches 0017–0025, the Forza recipe.
• Ferestre, by icex: Wine patches for the Xbox edition.
• xodus (GPL-3.0): MSIXVC packages and Xbox sign-in.
• Wine, and CodeWeavers for the CrossOver sources (LGPL-2.1-or-later).
• Apple's D3DMetal (Game Porting Toolkit).

GPL-3.0: this repository includes GPL-3.0 code from Highball and patches to xodus. The patches to Wine follow Wine's license, LGPL-2.1-or-later.