Get global rect of window, texture or screen. This is the real position /
rectangular area occupied by a screen or onscreen window, with respect to the
origin (0,0) of the desktop coordinate system. A secondary display screen will
have its top-left corner not at (0,0), but at a proper offset, depending if
mirror mode is on or off, and how your displays are arranged in the display
settings dialog. An onscreen window which is not displayed in fullscreen mode
will have its top-left and bottom-right corners properly set.