The Design And Realization Of Embedded Vehicle Navigation System Map Symbol Library

As an important part of the Vehicle Navigation System(VNS for short),Electronic Map display is the foundation of the human-computer interface. The Map Symbol Base System is one of the indispensable base functions in Electronic Map System. It is a tool for people to read geographic information,and it is also a key step in drawing. The exact and fast geographic information display is based on the design and realization of the Map Symbol Base System. On the other hand,the current popular Map Symbol Base softwares do not meet the demand of the embedded Vehicle Navigation System. So it is necessary to build a special Map Symbol Base system for VNS.In this paper,the author goes deep into the character and composition rule of point,line and area symbols,and the definition of Map Symbol Base is brought forward. Considering the demand of embedded system,this paper designs and realizes a Map Symbol Base for VNS specially. Some effective algorithms are presented:Line algorithms is the basic theories for the realization of line symbol. Based on the analysis on some classical line algorithms,the author puts forward some new line algorithms,which get results faster. And those algorithms can deal with different lines,which differ in type and width. All of these provide the key technique for the realization of line symbol. Since Polygon fill algorithm is very important for the realization of area symbol,there are lots of analysis on it. And different design methods are presented according to the difference of area symbols. Result shows that the improvements perform well in practice.