OVERLAP/DIFFERENCE AREA ARITHMETIC CONTROL METHOD AND WINDOW DISPLAY CONTROLLER EXECUTING THE SAME METHOD

PURPOSE:To automatically obtain both overlap and non-overlap rectangular areas between two rectangular window display areas by securing the positional relation among the side coordinates of both windows. CONSTITUTION:The left, upper, right and lower side coordinates of a window area 1 are defined as 100, 100, 300 and 160 respectively. While the same side coordinates of a window area 2 are defined as 200, 120, 400 and 200. Based on these coordinate data, a positional relation arithmetic means 1 uses a pre scribed positional relation sort code '1212' to show the positional relation between both window areas 1 and 2. At the same time, an overlap area arithme tic means 2 defines the overlap areas 200, 120, 300 and 200, and a difference area arithmetic means 3 defines a difference area including two rectangular areas (100, 100, 300 and 120) and (100, 120, 200 and 160). Thus, it is possible to automatically obtain both overlap and non-overlap rectangular areas between two display areas for rectangular windows.