#include <Polygon2.h>

Classes
class	SegmentEnumerable

class	SegmentIterator

Public Member Functions
	TPolygon2 ()

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

template<typename OtherVertexType >
	TPolygon2 (const TArray< OtherVertexType > &VertexList)

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

const TVector2< T > &	operator[] (int Index) const

TVector2< T > &	operator[] (int Index)

const TVector2< T > &	Start () const

const TArray< TVector2< T > > &	GetVertices () const

int	VertexCount () const

void	AppendVertex (const TVector2< T > &Position)

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

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

void	RemoveVertex (int VertexIndex)

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

void	Reverse ()

TVector2< T >	GetTangent (int VertexIndex) const

TVector2< T >	GetNormal (int VertexIndex) const

TVector2< T >	GetNormal_FaceAvg (int VertexIndex) const

TAxisAlignedBox2< T >	Bounds () const

SegmentIterator	SegmentItr () const

SegmentEnumerable	Segments () const

bool	IsClockwise () const

T	SignedArea () const

T	Area () const

T	Perimeter () const

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

void	NeighbourVectors (int VertexIdx, TVector2< T > &OutToPrev, TVector2< T > &OutToNext, bool bNormalize=false) const

T	OpeningAngleDeg (int iVertex) const

T	WindingIntegral (const TVector2< T > &QueryPoint) const

bool	IsConvex (T RadiansTolerance=TMathUtil< T >::ZeroTolerance, bool bDegenerateIsConvex=true) const

bool	Contains (const TVector2< T > &QueryPoint) const

bool	Overlaps (const TPolygon2< T > &OtherPoly) const

bool	Contains (const TPolygon2< T > &OtherPoly) const

bool	Contains (const TSegment2< T > &Segment) const

void	ClipConvex (const TAxisAlignedBox2< T > &Bounds)

bool	Intersects (const TPolygon2< T > &OtherPoly) const

bool	Intersects (const TSegment2< T > &Segment) const

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

TSegment2< T >	Segment (int SegmentIndex) const

TVector2< T >	GetSegmentPoint (int SegmentIndex, T SegmentParam) const

TVector2< T >	GetSegmentPointUnitParam (int SegmentIndex, T SegmentParam) const

TVector2< T >	GetNormal (int iSeg, T SegmentParam) const

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

T	DistanceSquared (const TVector2< T > &QueryPoint) const

T	AverageEdgeLength () const

TPolygon2< T > &	Translate (const TVector2< T > &Translate)

TPolygon2< T > &	Scale (const TVector2< T > &Scale, const TVector2< T > &Origin)

TPolygon2< T > &	Transform (const TFunction< TVector2< T >(const TVector2< T > &)> &TransformFunc)

void	VtxNormalOffset (T OffsetDistance, bool bUseFaceAvg=false)

void	PolyOffset (T OffsetDistance)

void	Simplify (T ClusterTolerance=0.0001, T LineDeviationTolerance=0.01)

void	Chamfer (T ChamferDist, T MinConvexAngleDeg=30, T MinConcaveAngleDeg=30)

Static Public Member Functions
static TPolygon2< T >	MakeRectangle (const TVector2< T > &Center, T Width, T Height)

static TPolygon2< T >	MakeRoundedRectangle (const TVector2< T > &Center, T Width, T Height, T Corner, int CornerSteps)

static TPolygon2< T >	MakeCircle (T Radius, int Steps, T AngleShiftRadians=0)

Protected Attributes
TArray< TVector2< T > >	Vertices

Friends
class	SegmentIterator

Detailed Description

template<typename T>
class UE::Geometry::TPolygon2< T >

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

Constructor & Destructor Documentation

◆ TPolygon2() [1/4]

template<typename T >

UE::Geometry::TPolygon2< T >::TPolygon2 ( )

inline

◆ TPolygon2() [2/4]

template<typename T >

UE::Geometry::TPolygon2< T >::TPolygon2 ( const TArray< TVector2< T > > & VertexList )

inline

Construct polygon with given list of vertices

◆ TPolygon2() [3/4]

template<typename T >

template<typename OtherVertexType >

UE::Geometry::TPolygon2< T >::TPolygon2 ( const TArray< OtherVertexType > & VertexList )

inline

◆ TPolygon2() [4/4]

template<typename T >

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

inline

Construct polygon with given indices into a vertex array

Member Function Documentation

◆ AppendVertex()

template<typename T >

void UE::Geometry::TPolygon2< T >::AppendVertex ( const TVector2< T > & Position )

inline

Add a vertex to the Polygon

◆ AppendVertices()

template<typename T >

void UE::Geometry::TPolygon2< T >::AppendVertices ( const TArray< TVector2< T > > & NewVertices )

inline

Add a list of Vertices to the Polygon

◆ Area()

template<typename T >

T UE::Geometry::TPolygon2< T >::Area ( ) const

inline

Returns: the unsigned area of the Polygon

◆ AverageEdgeLength()

template<typename T >

T UE::Geometry::TPolygon2< T >::AverageEdgeLength ( ) const

inline

Returns: average edge length of all the edges of the Polygon

◆ Bounds()

template<typename T >

TAxisAlignedBox2< T > UE::Geometry::TPolygon2< T >::Bounds ( ) const

inline

Returns: the bounding box of the Polygon Vertices

◆ Chamfer()

template<typename T >

void UE::Geometry::TPolygon2< T >::Chamfer	(	T	ChamferDist,
		T	MinConvexAngleDeg = `30`,
		T	MinConcaveAngleDeg = `30`
	)

inline

Chamfer each vertex corner of the Polygon

Parameters

ChamferDist offset distance from corner that we cut at

◆ ClipConvex()

template<typename T >

void UE::Geometry::TPolygon2< T >::ClipConvex ( const TAxisAlignedBox2< T > & Bounds )

inline

Clip polygon to the given bounds. Note that if the polygon is not convex, it may have overlapping edges at the bounds.

◆ Contains() [1/3]

template<typename T >

bool UE::Geometry::TPolygon2< T >::Contains ( const TPolygon2< T > & OtherPoly ) const

inline

Returns: true if the Polygon fully contains the OtherPolygon

◆ Contains() [2/3]

template<typename T >

bool UE::Geometry::TPolygon2< T >::Contains ( const TSegment2< T > & Segment ) const

inline

Returns: true if the Segment is fully contained inside the Polygon

◆ Contains() [3/3]

template<typename T >

bool UE::Geometry::TPolygon2< T >::Contains ( const TVector2< T > & QueryPoint ) const

inline

Returns: true if the given query point is inside the Polygon, based on the winding integral

◆ DistanceSquared() [1/2]

template<typename T >

T UE::Geometry::TPolygon2< T >::DistanceSquared ( const TVector2< T > & QueryPoint ) const

inline

Calculate the squared distance from a point to the polygon

Parameters

QueryPoint the query point

Returns: squared distance to the polygon

◆ DistanceSquared() [2/2]

template<typename T >

T UE::Geometry::TPolygon2< T >::DistanceSquared	(	const TVector2< T > &	QueryPoint,
		int &	NearestSegIndexOut,
		T &	NearestSegParamOut
	)		const

inline

Calculate the squared distance from a point to the polygon

Parameters

QueryPoint	the query point
NearestSegIndexOut	The index of the nearest segment
NearestSegParamOut	the parameter value of the nearest point on the segment

Returns: squared distance to the polygon

◆ FindIntersections()

template<typename T >

bool UE::Geometry::TPolygon2< T >::FindIntersections	(	const TPolygon2< T > &	OtherPoly,
		TArray< TVector2< T > > &	OutArray
	)		const

inline

Find all the points where an edge of the Polygon intersects an edge of the OtherPolygon

Parameters

OtherPoly	polygon to test against
OutArray	intersection points are stored here

Returns: true if any intersections were found

◆ GetNormal() [1/2]

template<typename T >

TVector2< T > UE::Geometry::TPolygon2< T >::GetNormal	(	int	iSeg,
		T	SegmentParam
	)		const

inline

Parameters

SegmentIndex	index of first vertex of the edge
SegmentParam	parameter in range [0,1] along segment

Returns: interpolated normal to the segment at the given parameter value

◆ GetNormal() [2/2]

template<typename T >

TVector2< T > UE::Geometry::TPolygon2< T >::GetNormal ( int VertexIndex ) const

inline

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

◆ GetNormal_FaceAvg()

template<typename T >

TVector2< T > UE::Geometry::TPolygon2< T >::GetNormal_FaceAvg ( int VertexIndex ) const

inline

Construct a normal at a vertex of the Polygon by averaging the adjacent face normals. This vector is independent of the lengths of the adjacent segments. Points "inward" for a Clockwise Polygon, and outward for CounterClockwise

◆ GetSegmentPoint()

template<typename T >

TVector2< T > UE::Geometry::TPolygon2< T >::GetSegmentPoint	(	int	SegmentIndex,
		T	SegmentParam
	)		const

inline

Parameters

SegmentIndex	index of first vertex of the edge
SegmentParam	parameter in range [-Extent,Extent] along segment

Returns: point on the segment at the given parameter value

◆ GetSegmentPointUnitParam()

template<typename T >

TVector2< T > UE::Geometry::TPolygon2< T >::GetSegmentPointUnitParam	(	int	SegmentIndex,
		T	SegmentParam
	)		const

inline

Parameters

SegmentIndex	index of first vertex of the edge
SegmentParam	parameter in range [0,1] along segment

Returns: point on the segment at the given parameter value

◆ GetTangent()

template<typename T >

TVector2< T > UE::Geometry::TPolygon2< T >::GetTangent ( int VertexIndex ) const

inline

Get the tangent vector at a vertex of the polygon, which is the normalized vector from the previous vertex to the next vertex

◆ GetVertices()

template<typename T >

const TArray< TVector2< T > > & UE::Geometry::TPolygon2< T >::GetVertices ( ) const

inline

Returns: list of Vertices of Polygon

◆ Intersects() [1/2]

template<typename T >

bool UE::Geometry::TPolygon2< T >::Intersects ( const TPolygon2< T > & OtherPoly ) const

inline

Returns: true if at least one edge of the OtherPolygon intersects the Polygon

◆ Intersects() [2/2]

template<typename T >

bool UE::Geometry::TPolygon2< T >::Intersects ( const TSegment2< T > & Segment ) const

inline

Returns: true if the Segment intersects an edge of the Polygon

◆ IsClockwise()

template<typename T >

bool UE::Geometry::TPolygon2< T >::IsClockwise ( ) const

inline

Returns: true if the Polygon Vertices have Clockwise winding order / orientation (signed area is negative)

◆ IsConvex()

template<typename T >

bool UE::Geometry::TPolygon2< T >::IsConvex	(	T	RadiansTolerance = `TMathUtil<T>::ZeroTolerance`,
		bool	bDegenerateIsConvex = `true`
	)		const

inline

Parameters

RadiansTolerance	Maximum turn in the 'wrong' direction that will still be considered convex (in radians)
bDegenerateIsConvex	What to return for degenerate input (less than 3 points or equivalent due to repeated points)

Returns: true if polygon is convex

◆ MakeCircle()

template<typename T >

static TPolygon2< T > UE::Geometry::TPolygon2< T >::MakeCircle	(	T	Radius,
		int	Steps,
		T	AngleShiftRadians = `0`
	)

inlinestatic

Construct a circular polygon

◆ MakeRectangle()

template<typename T >

static TPolygon2< T > UE::Geometry::TPolygon2< T >::MakeRectangle	(	const TVector2< T > &	Center,
		T	Width,
		T	Height
	)

inlinestatic

Construct a four-vertex rectangle polygon

◆ MakeRoundedRectangle()

template<typename T >

static TPolygon2< T > UE::Geometry::TPolygon2< T >::MakeRoundedRectangle	(	const TVector2< T > &	Center,
		T	Width,
		T	Height,
		T	Corner,
		int	CornerSteps
	)

inlinestatic

Construct a rounded rectangle polygon

◆ NeighbourPoints()

template<typename T >

void UE::Geometry::TPolygon2< T >::NeighbourPoints	(	int	VertexIdx,
		TVector2< T > &	OutPrevNbr,
		TVector2< T > &	OutNextNbr
	)		const

inline

Get the previous and next vertex positions for a given vertex of the Polygon

◆ NeighbourVectors()

template<typename T >

void UE::Geometry::TPolygon2< T >::NeighbourVectors	(	int	VertexIdx,
		TVector2< T > &	OutToPrev,
		TVector2< T > &	OutToNext,
		bool	bNormalize = `false`
	)		const

inline

Get the vectors from a given vertex to the previous and next Vertices, optionally normalized

◆ OpeningAngleDeg()

template<typename T >

T UE::Geometry::TPolygon2< T >::OpeningAngleDeg ( int iVertex ) const

inline

Returns: the opening angle in degrees at a vertex of the Polygon

◆ operator[]() [1/2]

template<typename T >

TVector2< T > & UE::Geometry::TPolygon2< T >::operator[] ( int Index )

inline

Get the vertex at a given index

◆ operator[]() [2/2]

template<typename T >

const TVector2< T > & UE::Geometry::TPolygon2< T >::operator[] ( int Index ) const

inline

Get the vertex at a given index

◆ Overlaps()

template<typename T >

bool UE::Geometry::TPolygon2< T >::Overlaps ( const TPolygon2< T > & OtherPoly ) const

inline

Check for polygon overlap, aka solid intersection. (In contrast, note that the "Intersects" method checks for edge intersection)

Returns: true if the Polygon overlaps the OtherPolygon.

◆ Perimeter()

template<typename T >

T UE::Geometry::TPolygon2< T >::Perimeter ( ) const

inline

Returns: the total perimeter length of the Polygon

◆ PolyOffset()

template<typename T >

void UE::Geometry::TPolygon2< T >::PolyOffset ( T OffsetDistance )

inline

Offset polygon by fixed distance, by offsetting and intersecting edges. CounterClockWise Polygon offsets "outwards", ClockWise "inwards".

◆ RemoveVertex()

template<typename T >

void UE::Geometry::TPolygon2< T >::RemoveVertex ( int VertexIndex )

inline

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

◆ Reverse()

template<typename T >

void UE::Geometry::TPolygon2< T >::Reverse ( )

inline

Reverse the order of the Vertices in the Polygon (ie switch between Clockwise and CounterClockwise)

◆ Scale()

template<typename T >

TPolygon2< T > & UE::Geometry::TPolygon2< T >::Scale	(	const TVector2< T > &	Scale,
		const TVector2< T > &	Origin
	)

inline

Scale the Polygon relative to a given point

Returns: the Polygon, so that you can chain calls like Translate().Scale()

◆ Segment()

template<typename T >

TSegment2< T > UE::Geometry::TPolygon2< T >::Segment ( int SegmentIndex ) const

inline

Returns: edge of the polygon starting at vertex SegmentIndex

◆ SegmentItr()

template<typename T >

SegmentIterator UE::Geometry::TPolygon2< T >::SegmentItr ( ) const

inline

◆ Segments()

template<typename T >

SegmentEnumerable UE::Geometry::TPolygon2< T >::Segments ( ) const

inline

Returns: an object that can be used in a range-based for loop to iterate over the Segments of the Polygon

◆ Set()

template<typename T >

void UE::Geometry::TPolygon2< T >::Set	(	int	VertexIndex,
		const TVector2< T > &	Position
	)

inline

Set vertex at given index to a new Position

◆ SetVertices()

template<typename T >

void UE::Geometry::TPolygon2< T >::SetVertices ( const TArray< TVector2< T > > & NewVertices )

inline

Replace the list of Vertices with a new list

◆ SignedArea()

template<typename T >

T UE::Geometry::TPolygon2< T >::SignedArea ( ) const

inline

Returns: the signed area of the Polygon

◆ Simplify()

template<typename T >

void UE::Geometry::TPolygon2< T >::Simplify	(	T	ClusterTolerance = `0.0001`,
		T	LineDeviationTolerance = `0.01`
	)

inline

Simplify the Polygon to reduce the vertex count

Parameters

ClusterTolerance	Vertices closer than this distance will be merged into a single vertex
LineDeviationTolerance	Vertices are allowed to deviate this much from the input polygon lines

◆ Start()

template<typename T >

const TVector2< T > & UE::Geometry::TPolygon2< T >::Start ( ) const

inline

Returns: first vertex of Polygon

◆ Transform()

template<typename T >

TPolygon2< T > & UE::Geometry::TPolygon2< T >::Transform ( const TFunction< TVector2< T >(const TVector2< T > &)> & TransformFunc )

inline

Apply an arbitrary transformation to the Polygon

Returns: the Polygon, so that you can chain calls like Translate().Scale()

◆ Translate()

template<typename T >

TPolygon2< T > & UE::Geometry::TPolygon2< T >::Translate ( const TVector2< T > & Translate )

inline

Translate the polygon

Returns: the Polygon, so that you can chain calls like Translate().Scale()

◆ VertexCount()

template<typename T >

int UE::Geometry::TPolygon2< T >::VertexCount ( ) const

inline

Returns: number of Vertices in Polygon

◆ VtxNormalOffset()

template<typename T >

void UE::Geometry::TPolygon2< T >::VtxNormalOffset	(	T	OffsetDistance,
		bool	bUseFaceAvg = `false`
	)

inline

Offset each point by the given Distance along vertex "normal" direction

Parameters

OffsetDistance	the distance to offset
bUseFaceAvg	if true, we offset by the average-face normal instead of the perpendicular-tangent normal

◆ WindingIntegral()

template<typename T >

T UE::Geometry::TPolygon2< T >::WindingIntegral ( const TVector2< T > & QueryPoint ) const

inline

Returns: analytic winding integral for this Polygon at an arbitrary point

Friends And Related Symbol Documentation

◆ SegmentIterator

template<typename T >

friend class SegmentIterator

friend

Member Data Documentation

◆ Vertices

template<typename T >

TArray<TVector2<T> > UE::Geometry::TPolygon2< T >::Vertices

protected

The list of vertices/corners of the polygon

The documentation for this class was generated from the following files:

Engine/Source/Runtime/GeometryCore/Public/CompGeom/Delaunay2.h
Engine/Source/Runtime/GeometryCore/Public/Polygon2.h

Classes

Public Member Functions

Static Public Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ TPolygon2() [1/4]

◆ TPolygon2() [2/4]

◆ TPolygon2() [3/4]

◆ TPolygon2() [4/4]

Member Function Documentation

◆ AppendVertex()

◆ AppendVertices()

◆ Area()

◆ AverageEdgeLength()

◆ Bounds()

◆ Chamfer()

◆ ClipConvex()

◆ Contains() [1/3]

◆ Contains() [2/3]

◆ Contains() [3/3]

◆ DistanceSquared() [1/2]

◆ DistanceSquared() [2/2]

◆ FindIntersections()

◆ GetNormal() [1/2]

◆ GetNormal() [2/2]

◆ GetNormal_FaceAvg()

◆ GetSegmentPoint()

◆ GetSegmentPointUnitParam()

◆ GetTangent()

◆ GetVertices()

◆ Intersects() [1/2]

◆ Intersects() [2/2]

◆ IsClockwise()

◆ IsConvex()

◆ MakeCircle()

◆ MakeRectangle()

◆ MakeRoundedRectangle()

◆ NeighbourPoints()

◆ NeighbourVectors()

◆ OpeningAngleDeg()

◆ operator[]() [1/2]

◆ operator[]() [2/2]

◆ Overlaps()

◆ Perimeter()

◆ PolyOffset()

◆ RemoveVertex()

◆ Reverse()

◆ Scale()

◆ Segment()

◆ SegmentItr()

◆ Segments()

◆ Set()

◆ SetVertices()

◆ SignedArea()

◆ Simplify()

◆ Start()

◆ Transform()

◆ Translate()

◆ VertexCount()

◆ VtxNormalOffset()

◆ WindingIntegral()

Friends And Related Symbol Documentation

◆ SegmentIterator

Member Data Documentation

◆ Vertices