Hooking DirectX EndScene from an injected DLL

Question

I want to detour EndScene from an arbitrary DirectX 9 application to create a small overlay. As an example, you could take the frame counter overlay of FRAPS, w

Answer 1

A slightly old question I know - but in case anyone is interested in doing this with C#, here is my example on hooking the Direct3D 9 API using C#. This utilizes EasyHook an open source .NET assembly that allows you to 'safely' install hooks from managed code into unmanaged functions. (Note: EasyHook takes care of all the issues surrounding DLL injection - e.g. CREATE_SUSPENDED, ACL's, 32 vs 64-bit and so on)

I use a similar VTable approach as mentioned by Christopher via a small C++ helper dll to dynamically determine the address of the IDirect3DDevice9 functions to hook. This is done by creating a temporary window handle, and creating a throw-away IDirect3Device9 within the injected assembly before then hooking the desired functions. This allows your application to hook a target that is already running (Update: note that this is possible entirely within C# also - see comments on the linked page).

Update: there is also an updated version for hooking Direct3D 9, 10 and 11 still using EasyHook and with SharpDX instead of SlimDX