基于约束Delaunay三角网的斜坡符号生成算法

Algorithm of Slope Symbol Generation with Constrained Delaunay Triangulation

分析了地图自动成图中斜坡坡面符号生成算法的基本原理,据此将斜坡分成梯形斜坡、矩形斜坡、倒梯形斜坡三种类型,并概括了他们的特点,介绍了已有的斜坡坡面符号生成算法及其优缺点,在此基础上,提出了一种基于约束Delaunay三角网的斜坡坡面符号生成算法,对预处理后的上下坡脚线建立约束Delaunay三角网,根据三角形组合的不同特点,将三角形的组合分类成两种类型,依次寻找匹配点,最后生成斜坡符号线。此算法避免了斜坡坡面符号线相交等情况,亦可用于栅栏等地图符号的自动生成。

The paper analyzes the basic principles of the automatic generation algorithm for the Ramp slope map symbol,which is classified into trapezoidal ramp,rectangular ramp and inverted trapezoidal slope types based on their characteristics.This paper summarizes the advantages and disadvantages of the existing automatic generation algorithm for the Ramp slope Map Symbol,Accordingly,we proposes the ramp slope map symbol generation algorithm with a constrained Delaunay triangulation.First,we establish a constrained Delaunay triangulation with toe polyline and top polyline of a Ramp slope,based on triangular characteristics,the triangles are classified into two types.Secondly,we find each pair of matching points,and generate the ramp symbol line.This algorithm avoids intersecting the ramp slope symbol lines and can also be used to automatically generat for those map symbols as the fence.