用C++实现的简单GIS系统，包括空间数据的（点、线、面）的存储，输入，显示，以及空间元素的编辑与修改，以及界面化的交互操作-Using C++, a simple GIS system, including spatial data (point, line, surface) of storage, input, display, and spatial elements of the editor and modify, as well as the interface of the in