基于GIS拓扑数据库的快速开窗与裁剪的研究

在地理信息系统（简称ＧＩＳ）的图形编辑、绘图、查询以及分析等子系统中，经常要从具有拓扑关系的图形数据库中提取并显示全部数据库图形的一部分，即“开窗与裁剪”，完成该功能可用软件来执行，但一般较为费时。笔者在深入研究图形拓扑数据结构、快速检索图形数据新方法和分析剪取窗口与弧段关系的基础上，给出基于弧段的开窗裁剪算法，在Ｂｏｒｌａｎｄ Ｃ＋＋环境下精心地进行程序设计与调试，实现了快速开窗与裁剪，准确而有

A Research on Rapid Window Openning and Cutting Based on Topological Databases of GIS

n many sub-systems of Geographic Information System,soch as graphic edit sub-system, plotting sub-system, etc., a pert of the map is often needed to draw and display from the Topological Databases, i. e. window opening and cutting. This function may be executed by software, but generally it cousumes a lot of time. Upon deep research into the topological graphic data structure, the authors put forward a new method of retrieving graphic data and analysed the relationship between the cutting window and an arc. The algorithm of window openning and cutting for arcs was given. The program was designed carefully and tested in the envioarment of Borlanal C and realized rabid window opening and cutting to form a new topological database for graphic displaying, selection of analyaing district and blotting,etc.