…Param. lParam contains two signed-short, the position can be negative when another mouse event happens with a mouse_move (mouse_click, etc.) The Microsoft documentation specifies NOT to use LOWORD and HIWORD macros to extract the x/y positions as it won't work correctly with multiple monitors. See http://msdn.microsoft.com/en-us/library/windows/desktop/ms645607(v=vs.85).aspx.
Fixed spelling of CV_INTER_LINEAR flag in geometric_transformations.rst
it uses float arithmetics