使用著名的Delaunay算法实现平面三角化。鼠标任意点击可增加、插入节点、形成网格；对节点标号，可逐步观查网格的变化，体验Delaunay算法过程。内有程序结构的详细说明，易于理解和移植。-2D-triangularization is realised based on the famous Delaunay algorithm in this program. While clicking the left mouse button, new nods with IDs are adde