MAP DISPLAY SYSTEM AND SCROLL PROCESSING METHOD THEREIN

摘要

PROBLEM TO BE SOLVED: To decrease the scroll processing during scroll, to enable the smooth scroll processing and to facilitate the identification of the position of a screen display range by executing reading out and plotting processing of only the lower layer data during the scroll processing and not executing the processing of upper layer data. SOLUTION: Map data is divided to the lower layer data and the upper layer data and is stored. The lower layer data is composed of the minimum required layer data for judging the position on the map among respective pieces of the layer data and the upper layer data is composed of the layer data exclusive thereof. When movement events occur continuously, the reading out and plotting processing of only the lower layer data among the respective pieces of the map data necessary by these movement events are carried out. The reading out and plotting processing of the upper layer data are thereafter not carried out and the reading out and plotting processing of only the lower layer data among the respective pieces of the map data necessary by the next movement events are carried out.