hwnd (HWND) - input
Identifies the window whose maximum size will be retrieved.
pswp (PSWP) - output
Points to the SWP structure that retrieves the size and position of a maximized window.
The SWP_SIZE and SWP_MOVE indicators are set in this parameter on return from this call, implying that the parameters have been initialized.
fSuccess (BOOL) - returns
TRUE