| 摘要 |
PURPOSE:To shorten processing time required for determining a dividing number and to attain the high speed of graphic processing including the curve processing of a polygonal line by calculating a distance on a straight line, for which a curve is approximated, and calculating the dividing number of the curve. CONSTITUTION:A graphic processing part 4 is equipped with a curve processing part 5 to execute processing to curve the polygonal line, and the curve processing part 5 is composed of a curve dividing part 7, which further determines a mid point between the end points of the curve and calculates the dividing number of the midpoint of the curve, and a curve calculating part 6 to calculate a curve equation and to calculate the coordinates of a point dividing the curve. When the polygonal is curved, at first, the midpoint between the both ends parts is calculated on the curve by the curve equation and the dividing number is determined according to the linear distance between the both end points and the midpoint. Next, the curve between the end point is divided by the dividing number and the coordinates of the dividing point are calculated. Thus, the time required for the curve processing of the polygonal line can be shortened. |
