| 摘要 |
PROBLEM TO BE SOLVED: To prevent the change of a required memory capacity without depending on the dispersion of object data. SOLUTION: In the case of sorting plural polygon data stored in an optional order in the increasing direction or decreasing direction of a specified reference value with the specified reference value as a reference and rearranging the plural polygon data, the respective reference values of the plural polygon data are divided into a high-order digit and a low-order digit and the numerical values of the high-order digit are registered in the order of the increasing direction or the decreasing direction. Then, corresponding to the numerical value of the low-order digit, the numerical value of the high-order digit, the numerical value of the corresponding low-order digit and an index number for indicating a position where the polygon data provided with the numerical value of the high-order digit are stored are registered and the polygon data registered in the order of the corresponding index number are read in the order of the increasing direction or decreasing direction of the registered numerical value of the high-order digit. |
