Русская версия

D3D9 Depth Proxy

A proxy implementation of d3d9.dll for Direct3D 9 applications.

The module wraps the IDirect3D9 and IDirect3DDevice9 interfaces, intercepting calls between the application and the real D3D9 backend.
Application behavior remains unchanged — the proxy acts as a transparent intermediate layer.

Project Goals

• D3D9 render research
• Graphics call logging
• Post-processing integration
• Depth buffer access
• Graphics pipeline analysis

Architecture

Application → d3d9.dll (proxy) → Real D3D9 backend (System / DXVK / Gallium Nine) → GPU

Two proxy classes are implemented:

• D3D9Proxy — wraps IDirect3D9
• D3D9DeviceProxy — wraps the full IDirect3DDevice9 interface

Backend Loading

This allows one build to work on:

• Native Windows
• Wine + DXVK
• Wine + Gallium Nine

Capabilities

Feature	Windows	DXVK	Gallium Nine
Transparent passthrough	✅	✅	✅
Render logging	✅	✅	✅
Depth buffer capture	✅	❌	✅
Color render target read	✅	✅	✅
Depth-based post effects	✅	❌	✅

DXVK blocks depth StretchRect by design due to Vulkan translation constraints.

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Installation

Place the proxy d3d9.dll next to the game executable.

Wine + DXVK:

Rename DXVK:   d3d9.dll → d3d9_dxvk.dll
Place proxy:   d3d9.dll  (this project)

Wine + Gallium Nine:

Place proxy:   d3d9.dll  (this project)
Wine will use Gallium Nine automatically as the backend.

Native Windows:

Place proxy:   d3d9.dll  (this project)
The proxy loads C:\Windows\System32\d3d9.dll automatically.

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Integration Point

Post-processing hooks into the Present() method:

HRESULT STDMETHODCALLTYPE Present(...) override {
    // When depth_captured == true, depth_tex holds the current frame's depth buffer.
    // Available on: native Windows, Gallium Nine.
    // Not available on: DXVK.

    return real->Present(a, b, c, d);
}

Depth capture happens automatically in SetRenderTarget when the offscreen → backbuffer transition is detected. At that moment depth contains world geometry and UI has not yet been drawn.

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Build

Linux (CMake + MinGW cross-compilation)

mkdir build && cd build
cmake .. -DCMAKE_TOOLCHAIN_FILE=../toolchain-mingw32.cmake
make

Linux (single command)

i686-w64-mingw32-g++ -std=c++17 -O2 -m32 -shared \
    -o d3d9.dll src/d3d9_proxy.cpp \
    -ld3d9 -ldxguid \
    -static-libgcc -static-libstdc++ \
    -Wl,--kill-at

Windows (CMake — Visual Studio)

mkdir build && cd build
cmake .. -G "Visual Studio 17 2022" -A Win32
cmake --build . --config Release

Windows (MSVC — manual)

1. Open Visual Studio 2019 or 2022
2. Create a new DLL project
3. Add src/d3d9_proxy.cpp
4. Set platform to x86 (Win32)
5. Project Properties → Linker → Input → Additional Dependencies:

d3d9.lib
dxguid.lib

6. Build in Release x86

Windows (MinGW)

i686-w64-mingw32-g++ -std=c++17 -O2 -m32 -shared \
    -o d3d9.dll src/d3d9_proxy.cpp \
    -ld3d9 -ldxguid \
    -static-libgcc -static-libstdc++ \
    -Wl,--kill-at

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Originally prototyped using AI-assisted development tools.