[DXGI] D3D Hook - Direct Hijack window

ID3D11Device       * Device = nullptr;
ID3D11DeviceContext* pContext = NULL;
IDXGISwapChain     * pSwapChain;
static uintptr_t hReturnAddress = NULL;

#define IatHook(A,O,N) \
	  if ( *(DWORD64*)(A) && *(DWORD64*)(A) != (DWORD64)(&N) )  { \
			*(DWORD64*)(&O) = *(DWORD64*)(A); \
			*(DWORD64*)(A) = (DWORD64)(&N); \
       }


void* (__cdecl* omemset) (void* str, int c, size_t n);

void* __cdecl nmemset ( void* str, int c, size_t n )
{
	if ( _ReturnAddress() == (void*)hReturnAddress )
	{
		pSwapChain = (IDXGISwapChain*)*(DWORD64*)str;
		if (pSwapChain)
		{
			if (!Device)
			{
				pSwapChain->GetDevice(__uuidof(Device), (void**)&Device);
				Device->GetImmediateContext(&pContext);
				add_log("", "pDevice %p pContext %p", Device, pContext);
			}


		}
	}
	return omemset(str, c, n);
}

void InitializeHook()
{

	uintptr_t hModule = GetModuleHandleW(L"dxgi.dll");


	add_log("", "dxgi.dll %p", hModule);

	hReturnAddress = (hModule+0x1678);


	add_log("", "hReturnAddress.dll %p", hReturnAddress);
	
	DWORD dwMemsetFlag;
	VirtualProtect((void*)(hModule+0x9EEC0),8,PAGE_READWRITE,&dwMemsetFlag);  //VirtualProtect Needed due to page protection
	IatHook((hModule+0x9EEC0), omemset, nmemset);
	VirtualProtect((void*)(hModule+0x9EEC0),8,dwMemsetFlag,&dwMemsetFlag);
}