dxvk-igdext

igdext64.dll for Wine/DXVK: lets games use Intel D3D11 Graphics Extensions (UAV overlap, MultiDrawIndirect, depth bounds) under Wine by forwarding them to DXVK's native implementation, instead of the game silently falling back to slower default D3D11 behavior when the extensions aren't available.

Note: Linux/Wine only for now, not for use on native Windows.

Build

cmake -B build -DCMAKE_TOOLCHAIN_FILE=./toolchain-mingw64.cmake
cmake --build build

Needs a MinGW-w64 cross toolchain. Produces build/igdext64.dll.

Note: the CMake project also configures and builds under MSVC (drop -DCMAKE_TOOLCHAIN_FILE) if you need to build it by hand on Windows.

Layout

src/           Modern (_INTC_-prefixed) extension context and public API types
├── dll/       DLL export entry points (Igdext.def + the exported functions)
└── legacy/    Legacy (pre-2019 ABI, non-INTC-prefixed) extension context and types

Deploy

igdext64.dll needs to end up at:

C:\windows\system32\DriverStore\FileRepository\igd_faux.inf_1\

On Linux, that maps to a real path under the Wine/Proton prefix's drive_c:

$WINEPREFIX/drive_c/windows/system32/DriverStore/FileRepository/igd_faux.inf_1/

or, for a Steam Proton prefix specifically:

<Steam library>/steamapps/compatdata/<appid>/pfx/drive_c/windows/system32/DriverStore/FileRepository/igd_faux.inf_1/

Handled automatically by Proton

A proton build places igdext64.dll there itself - no manual copy step. That only works if wine and dxvk include these commits:

• wine: the fake DX11 Intel UMD (igd10iumd64.dll) and that DriverStore path come from HACK/INTEL patches - fake UMD DLL, DriverInfPath, SetupGetInfDriverStoreLocationW
• DXVK: needs the [d3d11] Load Intel vendor hack DLL patch, which loads that fake UMD DLL
• proton: needs dxvk-igdext added as a submodule and wired into the build - TBD, not merged yet

Exports

igdext64.dll exports two API generations, because games can be built against either one depending on which version of Intel's SDK they linked:

• Legacy (D3D11CreateDeviceExtensionContext, etc., no _INTC_ prefix) - the pre-2019 ABI (LegacyD3D11ExtensionFuncs.h; the D3D12 counterpart is stub-only and needs no header of its own), taking ExtensionContextBase**/LegacyExtensionInfo* instead of the modern INTCExtensionContext**/INTCExtensionInfo*.
• Modern (_INTC_D3D11_*/_INTC_D3D12_*, plus a few loader-compat entry points without the underscore, like D3D11GetSupportedVersions2)
  • the current SDK's ABI.

Both generations exist side by side so either kind of game finds what it's looking for. D3D11 entries actually forward to DXVK; D3D12 entries are inert stubs (GetSupportedVersions reports zero, CreateDeviceExtensionContext always fails) kept only because igdext.lib's loader requires the export to exist at all.

All 38 exports are also listed by name in Igdext.def, the module definition file the linker uses to build the export table.

Export	Family	Behavior
D3D11CreateDeviceExtensionContext	Legacy D3D11	fills function table forwarding to DXVK
D3D11CreateDeviceExtensionContext1	Legacy D3D11	fills function table forwarding to DXVK
D3D11DestroyDeviceExtensionContext	Legacy D3D11	frees context
D3D11GetSupportedVersions	Legacy D3D11	reports hardcoded max version
D3D12CreateDeviceExtensionContext	Legacy D3D12	stub
D3D12DestroyDeviceExtensionContext	Legacy D3D12	stub
D3D12GetSupportedVersions	Legacy D3D12	stub
D3D11EnumInternalExtensions	Modern D3D11	reports zero (correct)
D3D11GetSupportedVersions2	Modern D3D11	reports hardcoded max version
_INTC_D3D11_BeginUAVOverlap	Modern D3D11	→ DXVK
_INTC_D3D11_EndUAVOverlap	Modern D3D11	→ DXVK
_INTC_D3D11_MultiDrawIndexedInstancedIndirect	Modern D3D11	→ DXVK
_INTC_D3D11_MultiDrawIndexedInstancedIndirectCountIndirect	Modern D3D11	→ DXVK
_INTC_D3D11_MultiDrawInstancedIndirect	Modern D3D11	→ DXVK
_INTC_D3D11_MultiDrawInstancedIndirectCountIndirect	Modern D3D11	→ DXVK
_INTC_D3D11_SetDepthBounds	Modern D3D11	→ DXVK
_INTC_D3D11_CreateTexture2D	Modern D3D11	→ plain CreateTexture2D, no DXVK ext
_INTC_D3D11_CreateDeviceExtensionContext	Modern D3D11	negotiates version, requires DXVK
_INTC_D3D11_CreateDeviceExtensionContext1	Modern D3D11	negotiates version, requires DXVK
_INTC_D3D11_GetSupportedVersions	Modern D3D11	reports hardcoded max version
_INTC_D3D11_RegisterApplicationCallbacks	Modern D3D11	stub, inert
D3D11CreateDeviceExtensionContext2	Modern D3D11 (loader-compat)	negotiates version, requires DXVK
_INTC_D3D11_INT_CreateDeviceExtensionContext	Modern D3D11 (Internal Extensions)	stub
D3D12EnumInternalExtensions	Modern D3D12	reports zero (correct)
D3D12GetSupportedVersions2	Modern D3D12	stub
_INTC_D3D12_CreateDeviceExtensionContext	Modern D3D12	stub
_INTC_D3D12_CreateDeviceExtensionContext1	Modern D3D12	stub
_INTC_D3D12_CreateDeviceExtensionContext2	Modern D3D12	stub
_INTC_D3D12_GetSupportedVersions	Modern D3D12	stub
_INTC_D3D12_RegisterApplicationCallbacks	Modern D3D12	stub, inert
D3D12CreateDeviceExtensionContext2	Modern D3D12 (loader-compat)	stub
_INTC_D3D12_INT_CreateDeviceExtensionContext	Modern D3D12 (Internal Extensions)	stub
_INTC_CreateDeviceExtensionContext	Modern D3D11+D3D12	D3D11 half negotiates version and requires DXVK, D3D12 half fails
_INTC_CreateDeviceExtensionContext1	Modern D3D11+D3D12	D3D11 half negotiates version and requires DXVK, D3D12 half fails
_INTC_DestroyDeviceExtensionContext	Modern D3D11+D3D12	frees context
D3D11D3D12CreateDeviceExtensionContext2	Modern D3D11+D3D12 (loader-compat)	D3D11 half negotiates version and requires DXVK, D3D12 half fails
D3D11D3D12DestroyDeviceExtensionContext2	Modern D3D11+D3D12 (loader-compat)	frees context
_INTC_INT_CreateDeviceExtensionContext	Modern D3D11+D3D12 (Internal Extensions)	stub