This thesis describes a new display management scheme for overlapping window systems. The primary purpose of this algorithm lies in the improvement of efficiency in window operations. Rob Pike had proposed a display management algorithm which uses minimal storage with the avoidance of redundant operations. By dividing the windows into visible and obscured parts, and only keeping obscured parts off-screen, it uses the minimum memory possible by letting the screen memory itself hold the visible parts. His algorithm, however, requires large amount of data transfers and tedious tracements of linked lists.
To improve the efficiency, we tried to reduce the overheads by the overall management of bitmaps which constitute windows collectively, and by the use of position information. Specially we compensated the fragmentation of bitmaps, which resulted from the Rob Pike's algorithm. The successful experimental results were compared with Rob Pike's algorithm.
