MWOn12 SDK · TeamVanilla

The MWOn12 SDK is how you write mods for Most Wanted under MWOn12. It has seven parts, and you can use any of them without the others.

Part	What it is
Plugins	A DLL that MWOn12 loads and hands the live Direct3D 12 device to, once per frame, with the back buffer ready to draw on. A C ABI, C++ helpers, a static library and samples.
ASI mods	The format most existing Most Wanted mods ship in. MWOn12 loads them before the game initialises, and they can still get the device every frame.
Hooking	Hook the game's own functions, patch memory, scan for byte patterns: gameplay, physics and AI, everything that never touches Direct3D.
Shader kit	Replace the game's shaders with your own HLSL. No code and no compiler: edit a text file and restart.
Graphics	See every draw and pipeline as the frame is built, drop draws, swap shaders at runtime, and read the buffers behind a draw, through VanGFX.
MWSDK	The game itself rather than its rendering: verified addresses, typed object views, live attributes, and the file formats.
User interface	VanGUI, built in, with the descriptor heap, the window hook and the backend lifecycles handled for you.

A plugin

A plugin is a 32-bit DLL in MWOn12\Plugins\ that exports one function. With the C++ helpers:

#include <mwon12/plugin.hpp>
#include <mwon12/overlay.hpp>

class MyPlugin final : public mwon12::Plugin {
public:
    const char* Name() const override { return "MyPlugin"; }

    void OnDeviceCreated(const MWOn12_DeviceInfo& d) override {
        m_ui.Init(static_cast<ID3D12Device*>(d.device),
                  static_cast<DXGI_FORMAT>(d.backBufferFormat), d.frameCount);
    }

    void OnPresent(const MWOn12_Frame& f) override {
        m_ui.Begin(f);
        m_ui.Rect(20, 20, 120, 10, 0xFF4040FF);   // x, y, w, h, 0xRRGGBBAA
        m_ui.Submit(static_cast<ID3D12GraphicsCommandList*>(f.commandList));
    }

    void OnDeviceDestroyed() override { m_ui.Shutdown(); }

private:
    mwon12::Overlay m_ui;
};

MWON12_PLUGIN(MyPlugin)

An ASI mod can join the same plugin system: MWOn12 exports MWOn12_RegisterPlugin, and <mwon12/asi.hpp> wraps it in one macro. Registration waits for the render thread, so callbacks always arrive there and never at the same time. The difference between an ASI and a plugin is when your code first runs, not what it's allowed to do.

Samples and tutorials

Five samples each exercise one part of the SDK:

FrameStats writes the frame rate to the log and draws nothing. Build it first: if its lines appear, your install is right.
HelloOverlay draws a frame-rate bar over the game.
GameHooks hooks, patches and scans.
VanGfxProbe counts draws and pipeline states.
GameSdk reads the live vehicle list through MWSDK.

Four tutorials build small, finished mods, each a standalone .asi: a full-screen colour grade with an F12 menu, stopping the police from spawning, a top-speed boost on a key press, and culling draws live from a menu.

Building

Build.bat

Visual Studio 2022 with the C++ workload. No DirectX SDK, no network, no package manager. It's C++23, because VanHooks and VanGFX are built on std::expected, and everything is x86, because speed.exe is 32-bit: CMake stops the build rather than let you produce a 64-bit plugin that loads into nothing.

Linking the whole SDK costs a plugin nothing it doesn't use. A static library only contributes the code you reference, so FrameStats.dll is 114,176 bytes and imports only KERNEL32.dll whether one dependency is linked or all four.