Class HalfEdgeGraph2d

Represents a 2D Graph with Half-edge connectivity, useful for finding polygons bounded by intersecting or overlapping edges.

Inheritance

System.Object

HalfEdgeGraph2d

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Elements.Spatial

Assembly: Hypar.Elements.dll

Syntax

public class HalfEdgeGraph2d

Properties

EdgesPerVertex

The index pairs, grouped by starting vertex, representing unique half edges.

Declaration

public List<List<(int from, int to, int? tag)>> EdgesPerVertex { get; set; }

Property Value

Type	Description
System.Collections.Generic.List<System.Collections.Generic.List<System.ValueTuple<System.Int32, System.Int32, System.Nullable<System.Int32>>>>

Vertices

The unique vertices of this graph

Declaration

public List<Vector3> Vertices { get; set; }

Property Value

Type	Description
System.Collections.Generic.List<Vector3>

Methods

Construct(Polygon, Polyline)

Construct a 2D Half Edge Graph from a polygon and an intersecting polyline.

Declaration

public static HalfEdgeGraph2d Construct(Polygon pg, Polyline pl)

Parameters

Type	Name	Description
Polygon	pg	The polygon.
Polyline	pl	The polyline.

Returns

Type	Description
HalfEdgeGraph2d

Construct(IEnumerable<Line>, Boolean)

Construct a 2D half-edge graph from a collection of lines.

Declaration

public static HalfEdgeGraph2d Construct(IEnumerable<Line> lines, bool bothWays = false)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Line>	lines	The line segments from which to construct the graph.
System.Boolean	bothWays	If true, each line will create two half edges — one running each way.

Returns

Type	Description
HalfEdgeGraph2d

Construct(IEnumerable<Polygon>, IEnumerable<Polyline>)

Construct a 2D Half Edge Graph from a collection of polygons and a collection of intersecting polylines.

Declaration

public static HalfEdgeGraph2d Construct(IEnumerable<Polygon> pg, IEnumerable<Polyline> pl)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Polygon>	pg	The polygons.
System.Collections.Generic.IEnumerable<Polyline>	pl	The polylines.

Returns

Type	Description
HalfEdgeGraph2d

Polygonize(Func<Nullable<Int32>, Boolean>, Vector3)

Calculate the closed polygons in this graph.

Declaration

public List<Polygon> Polygonize(Func<int?, bool> predicate = null, Vector3 normal = default(Vector3))

Parameters

Type	Name	Description
System.Func<System.Nullable<System.Int32>, System.Boolean>	predicate	A predicate used during the final step of polygonization to determine if edges are valid.
Vector3	normal	The normal of the plane in which graph traversal for polygon construction will occur. If no normal is provided, the +Z axis is used.

Returns

Type	Description
System.Collections.Generic.List<Polygon>	A collection of polygons.

Polylinize(Func<Nullable<Int32>, Boolean>, Vector3)

Calculate the closed polylines in this graph.

Declaration

public List<Polyline> Polylinize(Func<int?, bool> predicate = null, Vector3 normal = default(Vector3))

Parameters

Type	Name	Description
System.Func<System.Nullable<System.Int32>, System.Boolean>	predicate	A predicate used during the final step of polylinization to determine if edges are valid.
Vector3	normal	The normal of the plane in which graph traversal for polyline construction will occur. If no normal is provided, the +Z axis is used.

Returns

Type	Description
System.Collections.Generic.List<Polyline>	A collection of polylines.