| 摘要 |
PURPOSE: To effect a fast painting-out process by providing two digital differential analyzers(DDA) which find the panting-out border of a polygon is addition to a DDA which finds pixels to be painted out. CONSTITUTION: This plotting device has the 1st and 2nd DDAs 2 and 3 equipped with DDA arithmetic parts, X-axial counters, Y-axial counters, and clock control parts 5 and 8 controlling a clock for operating them and the 3rd DDA 16 which finds pixels to actually be drawn from the arithmetic results of the 1st and 2nd DDAs 2 and 3, and is equipped with a DDA control part 15 for controlling the 1st, 2nd, and 3rd DDAs 2, 3, and 16; and the 1st and 2nd DDAs 2 and 3 operate the border of a figure to be painted out to paint out the polygon. Consequently, the need to divide the polygon is eliminated, the start and end pints of a straight line to be plotted are calculated fast, and the frequency of transfer of data to the DDAs is decreased, so that the polygon is painted out fast. |
