code: def cursor_event(self, x, y, dx, dy):
          
          self.sys_camera.rot_state(x, y)
docs: The standard mouse movement event method.
          Can be overriden to add new functionality.
          By default this feeds the system camera with new values.
  
          Args:
              x: The current mouse x position
              y: The current mouse y position
              dx: Delta x postion (x position difference from the previous event)
              dy: Delta y postion (y position difference from the previous event)