| 摘要 |
PURPOSE:To obtain a linear approximate figure of good quality even when a Bezier curve is enlarged or reduced by changing the number of steps of parameters dynamically with the length and curvature of the Bezier curve when coordinates on the Bezier curve are calculated so as to approximate the Bezier curve. CONSTITUTION:Coordinates found by a Bezier curve calculating circuit 2a are Pt1' and the straight line approximated with them is (f). Then an angle calculating circuit 3 finds angles alpha and beta between the coordinates from data obtained by Bezier curve calculating circuits 2a-2c, i.e. coordinate data on Pt1', Pt, and Pt1'', and judges that the curvature of the Bezier curve is large when the angle alpha is larger than a certain value, and a selector 5 selects the output of the Bezier curve calculating circuit 2a. Further, when alpha+beta is smaller than a certain value, it is judged that the curvature of the Bezier is small and the selector 5 selects the output of the Bezier curve calculating circuit 2c. In other cases, the output of the Bezier calculating circuit 2b is selected. Consequently, linear approximation data on the Bezier curve (a) is obtained. |
