摘要 |
PROBLEM TO BE SOLVED: To draw a quadrilateral without any drawing omission irrelevantly to its size and shape although a figure drawn by a conventional quadrilateral drawing method possibly has a drawing omission depending upon the size and shape of the drawn quadrilateral. SOLUTION: In an arithmetic precision calculating process S1, the size of an error generated in drawing is checked and in a quadrilateral dividing process S2, the quadrilateral is divided so that the error is suppressed within a range where no drawing omission is caused. Consequently, segments are repeatedly drawn in a start-point and end-point calculating process S3 and a segment drawing process S4 to draw the quadrilateral having no drawing omission. The division size can be predetermined by estimating the worst case of an occurring error and in this case, calculation precision need not be computed in drawing. |