Before it can gain access to the mouse, your application must set the mouse device's behavior using the IDirectInputDevice8::SetCooperativeLevel method. This method accepts the handle to the window to be associated with the device. In Scrawl, the DISCL_EXCLUSIVE flag is included to ensure that this application is the only one that can have exclusive access to the device. This flag is combined with DISCL_FOREGROUND because Scrawl should not allow data input when another application is in the foreground.
The following code sample attempts to set the device's cooperative level. If this attempt fails, FALSE is returned. It is assumed that hWnd is a valid window handle.
hr = g_pMouse->SetCooperativeLevel(hWnd, DISCL_EXCLUSIVE | DISCL_FOREGROUND); if (FAILED(hr)) { return FALSE; }
After setting the mouse behavior, go to Step 4: Preparing for Buffered Input from the Mouse.