| 摘要 |
PURPOSE:To store a wide range of graphic information and to improve resolution, by providing an arithmetic part to express a graphic data being expressed in an absolute coordinate as a coordinate in the coordinate space of a graphic CRT display device, on a host computer side. CONSTITUTION:The graphic information, for example, map information is stored in the auxiliary memory part 11 of the host computer 1 by the absolute coordinate in the coordinate space of the computer 1. The absolute coordinate is expressed setting the coordinate of a point O at a left lower point on a virtual huge screen in the memory part 11 as reference. In the computer 1, the arithmetic part 12 is provided, and the arithmetic part 12 retrieves a display range corresponding to a display request out of the map information in the memory part 11, and finds the coordinate of the point at the left lower point which becomes a reference point in the range, and converts each coordinate of the graphic data in the display range to a relative coordinate for the reference point. Thus, it is possible to store the wide range of map information, and to improve the resolution on a CRT monitor 7. |
