| 摘要 |
<p>PURPOSE:To speedily and easily display a map as a display object by dividing the map meshwise, finding an area number where respective map data exist, preserving them as a bit sequence, comparing the bit sequence of a display area with the bit sequence of the preserved map data at the time of display and deciding the map as a display object when they are equal to each other. CONSTITUTION:This system is provided with a display area number calculating means 2 for respectively dividing the entire map into plural areas in X and Y directions, applying the area numbers, and erasing map data 6 of the bit sequence equipped with only the area number, to which no bit is set, as data out of the display object based on the bit sequences in the X and Y directions previously stored by setting the area numbers existing every map data 6 and the bit sequences in the X and Y directions prepared by setting the bit of the area numbers existent in the designated display area on the map. Then, the map data 6 of the non-erased bit sequences are displayed in the display area.</p> |
