计算几何课堂：DCEL（双向边链表）

这里为单独介绍DCEL数据结构的讲解视频，这个数据结构隶属于几何寻路项目之中，关于其他算法，有兴趣的童鞋可以参考这个系列视频：计算几何课堂：几何寻路之旅

1. 视频章节：DCEL（双向边链表）

6.1 DCEl是什么？

6.2 例子：DCEL

6.3 基本操作

6.4 如何合并边

6.5 如何计算两边夹角

2. 拓展阅读

1. 向量复习（一）：定义、求解、四则运算、点积和叉积
2. 超详细！红黑树详解文章汇总（含代码）
3. 几何求交（一）：直线和直线的交点
4. 几何求交（二）：直线和圆的交点

3. 附录：项目代码

个人作业项目代码：Algorithm

2.3.1.1 Vertex

Description	Entry File
Get all incident edges of the vertex	public List<HalfEdge> allIncidentEdges()
Find the first ClockWise Edge with two vertices destination and origin	HalfEdge firstClockWiseEdge( Vertex origin )
Find the first CounterClockWise Edge with two vertices destination and origin	HalfEdge firstCounterClockWiseEdge( Vertex destination )
Connect two vertices by adding new half-edges	Face connect( Vertex v )
Re-connect half-edges incident to this vertex.(Duality Implementation)	void connect( List<HalfEdge> E )

2.3.1.2 Half-edge

Description	Entry File
Walk around all halfEdges connected to this one, and get vertices incident to them.	List<Vertex> walkAroundVertex()
Walk around and get all halfEdges connected to this one.	List<HalfEdge> walkAroundEdge()
Split the edge into two parts	Vertex split( Vertex split )
Get all inner faces bounded by this half-edge, but not including holes.	Collection<HalfEdge> getInners()
Sort half-edges in clock wise order with the point i as the center.	List<HalfEdge> sortInClockWise( List<HalfEdge> E, Vector i )

2.3.1.3 Face

Description	Entry File
Walk around all halfEdges, starting at this face and get visited halfEdges.	List<HalfEdge> walkAroundEdge()
Walk around all halfEdges, starting at this face and get visited vertices.	List<Vertex> walkAroundVertex()
Is the point inside this convex hull? but excluding the boundary.	boolean isInsideConvexHull( Vector p )
Is the point on this convex hull? including the boundary.	boolean isOnConvexHull( Vector p )
Is the point inside This Polygon?	boolean isInsidePolygon( Vector p )
Is the point On This Polygon?	boolean isOnPolygon( Vector p )

4. 参考资料

1. 计算几何 | Computational Geometry
2. Computational Geometry: Algorithms and Applications
3. Simple Stupid Funnel Algorithm

5. 免责声明

※ 本文之中如有错误和不准确的地方，欢迎大家指正哒~
※ 此项目仅用于学习交流，请不要用于任何形式的商用用途，谢谢呢；

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