| 摘要 |
PURPOSE: To accelerate the plotting speed at the time of plotting a small circle by performing reduction arithmetic to respective apex coordinate values based on the size of the circle to be plotted, calculating the coordinates of respective apexes to form the plotted circle and displaying the plotted circle by connecting the coordinates of respective mutually adjacent apexes among those respective calculated apexes. CONSTITUTION: Based on the size of the circle to be plotted, the respective apex coordinate values are thinned and extracted from a basic circle coordinate memory 1 by a skip number memory 2 and a microprocessor 3 as apex coordinate thinning means. The reduction arithmetic is performed to those respective extracted apex coordinate values based on the size of the circle to be plotted by the microprocessor 3 as an apex coordinate calculating means and the coordinates of respective apexes to form the plotted circle are calculated. The plotted circle is displayed by connecting the coordinates of respective mutually adjacent apexes among those respective calculated apex coordinates while using a straight line plotting means 5, frame memory 6, display control part 7 and monitor 9 as plotted circle display means. Thus, plotting speed at the time of plotting the small circle can be accelerated. |
