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TPolygon2

[TPolygon2](API\Runtime\GeometryCore\TPolygon2) is a 2D polygon represented as a list of Vertices.

API > API/Runtime > API/Runtime/GeometryCore

References

   
Module GeometryCore
Header /Engine/Source/Runtime/GeometryCore/Public/Polygon2.h
Include #include "Polygon2.h"

Syntax

template<typename T>  
class TPolygon2

Remarks

TPolygon2 is a 2D polygon represented as a list of Vertices.

Variables

  Type Name Description
Protected variable TArray< TVector2< T > > Vertices The list of vertices/corners of the polygon

Constructors

  Type Name Description
Public function    
Public function  

TPolygon2 ( const TArray< TVector2< T >>& VertexList
)

 Construct polygon with given list of vertices
Public function  

TPolygon2 ( const TArray< OtherVertexType >& VertexList
)

  
Public function  

TPolygon2 ( TArrayView< const TVector2< T >> VertexArray,
TArrayView< const int32 > VertexIndices
)

 Construct polygon with given indices into a vertex array

Functions

  Type Name Description
Public function void

AppendVertex ( const TVector2< T >& Position
)

 Add a vertex to the Polygon
Public function void

AppendVertices ( const TArray< TVector2< T >>& NewVertices
)

 Add a list of Vertices to the Polygon
Public function Const T

Area ()

  
Public function Const T  
Public function Const TAxisAlignedBox2< T >

Bounds ()

  
Public function void

Chamfer ( T ChamferDist,
T MinConvexAngleDeg,
T MinConcaveAngleDeg
)

 Chamfer each vertex corner of the Polygon
Public function void

ClipConvex ( const TAxisAlignedBox2< T >& Bounds
)

 Clip polygon to the given bounds.
Public function Const bool

Contains ( const TSegment2< T >& Segment
)

  
Public function Const bool

Contains ( const TPolygon2< T >& OtherPoly
)

  
Public function Const bool

Contains ( const TVector2< T >& QueryPoint
)

  
Public function Const T

DistanceSquared ( const TVector2< T >& QueryPoint,
int& NearestSegIndexOut,
T& NearestSegParamOut
)

 Calculate the squared distance from a point to the polygon
Public function Const T

DistanceSquared ( const TVector2< T >& QueryPoint
)

 Calculate the squared distance from a point to the polygon
Public function Const bool

FindIntersections ( const TPolygon2< T >& OtherPoly,
TArray< TVector2< T >>& OutArray
)

 Find all the points where an edge of the Polygon intersects an edge of the OtherPolygon
Public function Const TVector2< T >

GetNormal ( int iSeg,
T SegmentParam
)

  
Public function Const TVector2< T >

GetNormal ( int VertexIndex
)

 Get the normal vector at a vertex of the polygon, which is perpendicular to GetTangent() Points "inward" for a Clockwise Polygon, and outward for CounterClockwise
Public function Const TVector2< T >

GetNormal_FaceAvg ( int VertexIndex
)

 Construct a normal at a vertex of the Polygon by averaging the adjacent face normals.
Public function Const TVector2< T >

GetSegmentPoint ( int SegmentIndex,
T SegmentParam
)

  
Public function Const TVector2< T >

GetSegmentPointUnitParam ( int SegmentIndex,
T SegmentParam
)

  
Public function Const TVector2< T >

GetTangent ( int VertexIndex
)

 Get the tangent vector at a vertex of the polygon, which is the normalized vector from the previous vertex to the next vertex
Public function Const const TArray< TVector2< T > > &  
Public function Const bool

Intersects ( const TPolygon2< T >& OtherPoly
)

  
Public function Const bool

Intersects ( const TSegment2< T >& Segment
)

  
Public function Const bool  
Public function Const bool

IsConvex ( T RadiansTolerance,
bool bDegenerateIsConvex
)

  
Public function Static TPolygon2< T >

MakeCircle ( T Radius,
int Steps,
T AngleShiftRadians
)

 Construct a circular polygon
Public function Static TPolygon2< T >

MakeRectangle ( const TVector2< T >& Center,
T Width,
T Height
)

 Construct a four-vertex rectangle polygon
Public function Static TPolygon2< T >

MakeRoundedRectangle ( const TVector2< T >& Center,
T Width,
T Height,
T Corner,
int CornerSteps
)

 Construct a rounded rectangle polygon
Public function Const void

NeighbourPoints ( int VertexIdx,
TVector2< T >& OutPrevNbr,
TVector2< T >& OutNextNbr
)

 Get the previous and next vertex positions for a given vertex of the Polygon
Public function Const void

NeighbourVectors ( int VertexIdx,
TVector2< T >& OutToPrev,
TVector2< T >& OutToNext,
bool bNormalize
)

 Get the vectors from a given vertex to the previous and next Vertices, optionally normalized
Public function Const T

OpeningAngleDeg ( int iVertex
)

  
Public function Const bool

Overlaps ( const TPolygon2< T >& OtherPoly
)

 Check for polygon overlap, aka solid intersection.
Public function Const T  
Public function void

PolyOffset ( T OffsetDistance
)

 Offset polygon by fixed distance, by offsetting and intersecting edges.
Public function void

RemoveVertex ( int VertexIndex
)

 Remove a vertex of the Polygon (existing Vertices are shifted)
Public function void

Reverse ()

 Reverse the order of the Vertices in the Polygon (ie switch between Clockwise and CounterClockwise)
Public function TPolygon2< T > &

Scale ( const TVector2< T >& Scale,
const TVector2< T >& Origin
)

 Scale the Polygon relative to a given point
Public function Const TSegment2< T >

Segment ( int SegmentIndex
)

  
Public function Const SegmentIterator  
Public function Const SegmentEnumerable  
Public function void

Set ( int VertexIndex,
const TVector2< T >& Position
)

 Set vertex at given index to a new Position
Public function void

SetVertices ( const TArray< TVector2< T >>& NewVertices
)

 Replace the list of Vertices with a new list
Public function Const T  
Public function void

Simplify ( T ClusterTolerance,
T LineDeviationTolerance
)

 Simplify the Polygon to reduce the vertex count
Public function Const const TVector2< T > &

Start ()

  
Public function TPolygon2< T > &

Transform ( const TFunction< TVector2< T >(const TVector2< T >&)>& TransformFunc
)

 Apply an arbitrary transformation to the Polygon
Public function TPolygon2< T > &

Translate ( const TVector2< T >& Translate
)

 Translate the polygon
Public function Const int  
Public function void

VtxNormalOffset ( T OffsetDistance,
bool bUseFaceAvg
)

 Offset each point by the given Distance along vertex "normal" direction
Public function Const T

WindingIntegral ( const TVector2< T >& QueryPoint
)

  

Operators

  Type Name Description
Public function Const const TVector2< T > &

operator[] ( int Index
)

 Get the vertex at a given index
Public function TVector2< T > &

operator[] ( int Index
)

 Get the vertex at a given index

Classes

  Type Name Description
Public class SegmentEnumerable Wrapper around SegmentIterator that has begin() and end() suitable for range-based for loop  
Public class SegmentIterator SegmentIterator is used to iterate over the TSegment2 segments of the polygon  

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