| 摘要 |
PURPOSE:To generate a desired parameter curved line at high speed in a ratio of one point to two clock cycles on the average by performing a bi-secting operation on the control point of a Bezier curved line supplied to a register in advance repeatedly. CONSTITUTION:The x-coordinate and y-coordinate of each control point of the curved line to be generated are set on a parameter curved line generator. After that, the x-coordinate and the y-coordinate of the each control point of the Bezier curved line divided sequentially are held at a register 11. A bi- secting circuit 12 generates each control point of two pairs of Bezier curved line by performing the operation of a calculation equation to compute the control point Pi' and the control point Pi''. A stack memory 13 holds each control point of the Bezier curved surface on one side of the two pairs generated at the circuit 12. A judging circuit 14 checks the extent of the division of the Bezier curved line based on the content of the register 11, and judges whether or not bi-secting should be continued further. In such a manner, the desired parameter curved line can be generated by performing the bi-secting operation on the control point of the Bezier curved surface repeatedly. |
