Class QuadEdgeTriangle

Models a triangle formed from QuadEdges in a QuadEdgeSubdivision which forms a triangulation. The class provides methods to access the topological and geometric properties of the triangle and its neighbours in the triangulation. Triangle vertices are ordered in CCW orientation in the structure.

Inheritance

object

QuadEdgeTriangle

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: NetTopologySuite.Triangulate.QuadEdge

Assembly: NetTopologySuite.dll

Syntax

public class QuadEdgeTriangle

Remarks

QuadEdgeTriangles support having an external data attribute attached to them. Alternatively, this class can be subclassed and attributes can be defined in the subclass. Subclasses will need to define their own BuilderVisitor class and CreateOn method.

Constructors

QuadEdgeTriangle(QuadEdge[])

Creates a new triangle from the given edges.

Declaration

public QuadEdgeTriangle(QuadEdge[] edge)

Parameters

Type	Name	Description
QuadEdge[]	edge	An array of the edges of the triangle in CCW order

Properties

Data

Gets or sets the external data value for this triangle.

Declaration

public object Data { get; set; }

Property Value

Type	Description
object

Methods

Contains(Coordinate)

Declaration

public bool Contains(Coordinate pt)

Parameters

Type	Name	Description
Coordinate	pt

Returns

Type	Description
bool

Contains(QuadEdge[], Coordinate)

Tests whether the point pt is contained in the triangle defined by 3 QuadEdgees.

Declaration

public static bool Contains(QuadEdge[] tri, Coordinate pt)

Parameters

Type	Name	Description
QuadEdge[]	tri	an array containing at least 3 QuadEdges
Coordinate	pt	the point to test

Returns

Type	Description
bool	true if the point is contained in the triangle

Contains(Vertex[], Coordinate)

Tests whether the point pt is contained in the triangle defined by 3 Vertexes.

Declaration

public static bool Contains(Vertex[] tri, Coordinate pt)

Parameters

Type	Name	Description
Vertex[]	tri	an array containing at least 3 Vertexes
Coordinate	pt	the point to test

Returns

Type	Description
bool	true if the point is contained in the triangle

CreateOn(QuadEdgeSubdivision)

Creates QuadEdgeTriangles for all facets of a QuadEdgeSubdivision representing a triangulation. The data attributes of the QuadEdges in the subdivision will be set to point to the triangle which contains that edge. This allows tracing the neighbour triangles of any given triangle.

Declaration

public static IList<QuadEdgeTriangle> CreateOn(QuadEdgeSubdivision subdiv)

Parameters

Type	Name	Description
QuadEdgeSubdivision	subdiv	The QuadEdgeSubdivision to create the triangles on.

Returns

Type	Description
IList<QuadEdgeTriangle>	A List of the created QuadEdgeTriangles

GetAdjacentTriangleAcrossEdge(int)

Declaration

public QuadEdgeTriangle GetAdjacentTriangleAcrossEdge(int edgeIndex)

Parameters

Type	Name	Description
int	edgeIndex

Returns

Type	Description
QuadEdgeTriangle

GetAdjacentTriangleEdgeIndex(int)

Declaration

public int GetAdjacentTriangleEdgeIndex(int i)

Parameters

Type	Name	Description
int	i

Returns

Type	Description
int

GetCoordinate(int)

Declaration

public Coordinate GetCoordinate(int i)

Parameters

Type	Name	Description
int	i

Returns

Type	Description
Coordinate

GetCoordinates()

Declaration

public Coordinate[] GetCoordinates()

Returns

Type	Description
Coordinate[]

GetEdge(int)

Declaration

public QuadEdge GetEdge(int i)

Parameters

Type	Name	Description
int	i

Returns

Type	Description
QuadEdge

GetEdgeIndex(QuadEdge)

Gets the index for the given edge of this triangle

Declaration

public int GetEdgeIndex(QuadEdge e)

Parameters

Type	Name	Description
QuadEdge	e	a QuadEdge

Returns

Type	Description
int	the index of the edge in this triangle, or -1 if the edge is not an edge of this triangle

GetEdgeIndex(Vertex)

Gets the index for the edge that starts at vertex v.

Declaration

public int GetEdgeIndex(Vertex v)

Parameters

Type	Name	Description
Vertex	v	the vertex to find the edge for

Returns

Type	Description
int	the index of the edge starting at the vertex, or -1 if the vertex is not in the triangle

GetEdgeSegment(int, LineSegment)

Declaration

public void GetEdgeSegment(int i, LineSegment seg)

Parameters

Type	Name	Description
int	i
LineSegment	seg

GetEdges()

Declaration

public QuadEdge[] GetEdges()

Returns

Type	Description
QuadEdge[]

GetGeometry(GeometryFactory)

Declaration

public Geometry GetGeometry(GeometryFactory fact)

Parameters

Type	Name	Description
GeometryFactory	fact

Returns

Type	Description
Geometry

GetNeighbours()

Gets the neighbours of this triangle. If there is no neighbour triangle, the array element is null

Declaration

public QuadEdgeTriangle[] GetNeighbours()

Returns

Type	Description
QuadEdgeTriangle[]	an array containing the 3 neighbours of this triangle

GetTrianglesAdjacentToVertex(int)

Gets the triangles which are adjacent (include) to a given vertex of this triangle.

Declaration

public IList<QuadEdgeTriangle> GetTrianglesAdjacentToVertex(int vertexIndex)

Parameters

Type	Name	Description
int	vertexIndex	The vertex to query

Returns

Type	Description
IList<QuadEdgeTriangle>	A list of the vertex-adjacent triangles

GetVertex(int)

Declaration

public Vertex GetVertex(int i)

Parameters

Type	Name	Description
int	i

Returns

Type	Description
Vertex

GetVertices()

Gets the vertices for this triangle.

Declaration

public Vertex[] GetVertices()

Returns

Type	Description
Vertex[]	a new array containing the triangle vertices

IsBorder()

Tests whether this triangle is adjacent to the outside of the subdivision.

Declaration

public bool IsBorder()

Returns

Type	Description
bool	true if the triangle is adjacent to the subdivision exterior

IsBorder(int)

Declaration

public bool IsBorder(int i)

Parameters

Type	Name	Description
int	i

Returns

Type	Description
bool

IsLive()

Declaration

public bool IsLive()

Returns

Type	Description
bool

Kill()

Declaration

public void Kill()

ToPolygon(QuadEdge[])

Declaration

public static Geometry ToPolygon(QuadEdge[] e)

Parameters

Type	Name	Description
QuadEdge[]	e

Returns

Type	Description
Geometry

ToPolygon(Vertex[])

Declaration

public static Geometry ToPolygon(Vertex[] v)

Parameters

Type	Name	Description
Vertex[]	v

Returns

Type	Description
Geometry

ToString()

Declaration

public override string ToString()

Returns

Type	Description
string

Overrides

object.ToString()