D3D11 fullscreen fix

Engine/source/gfx/D3D11/gfxD3D11Device.cpp

@@ -427,6 +427,8 @@ void GFXD3D11Device::enumerateVideoModes()
 void GFXD3D11Device::init(const GFXVideoMode &mode, PlatformWindow *window)
 {
    AssertFatal(window, "GFXD3D11Device::init - must specify a window!");
+   HWND hwnd = (HWND)window->getSystemWindow(PlatformWindow::WindowSystem_Windows);
+   SetFocus(hwnd);//ensure window has focus
 
    UINT createDeviceFlags = D3D11_CREATE_DEVICE_SINGLETHREADED | D3D11_CREATE_DEVICE_BGRA_SUPPORT;
 #ifdef TORQUE_DEBUG