| 摘要 |
PURPOSE:To increase the clipping speed by performing the clipping process only in a rectangular area where the segments cross to each other and performing no clipping process in a rectangular area no segment may possibly pass through. CONSTITUTION:A display device 1 is provided to display plural windows on a display screen together with a display control part 2 which controls the device 1, and a memory part 3 which stores the drawn pattern data and the window divided rectangle information. The part 2 includes a 1st clipping circuit 2-1 which performs the clipping operation to the desired one of those window areas stored in the part 3, and a 2nd clipping circuit 2-2 which performs the clipping operation to a divided rectangular area of the desired window area in a rectangular area where a segment intersecting point is formed when the circuit 2-1 detects the segment intersecting point. Thus a process where the segment intersecting point is obtained on a multi-window screen and the clipping operation is carried out can be performed at a high speed. |
