UE::Geometry::TConvexHull2< RealType > Class Template Reference

#include <ConvexHull2.h>

Public Member Functions
GEOMETRYCORE_API bool	SolveSimplePolygon (int32 NumPolygonPoints, TFunctionRef< TVector2< RealType >(int32)> GetPointFunc, bool bIsKnownCCW=false)
GEOMETRYCORE_API bool	Solve (int32 NumPoints, TFunctionRef< TVector2< RealType >(int32)> GetPointFunc, TFunctionRef< bool(int32)> FilterFunc=[](int32 Idx) {return true;})
bool	Solve (TArrayView< const TVector2< RealType > > Points, TFunctionRef< bool(int32)> FilterFunc)
bool	Solve (TArrayView< const TVector2< RealType > > Points)
bool	IsSolutionAvailable () const
void	Empty ()
int32	GetDimension () const
int32	GetNumUniquePoints () const
TArray< int32 > const &	GetPolygonIndices () const
TLine2< RealType >	GetLine (TArrayView< const TVector2< RealType > > Points) const

Protected Member Functions
void	GetHull (TFunctionRef< TVector2< RealType >(int32)> GetPointFunc, TArray< int32 > &Merged, int32 &IdxFirst, int32 &IdxLast)
void	Merge (TFunctionRef< TVector2< RealType >(int32)> GetPointFunc, TArray< int32 > &Merged, int32 j0, int32 j1, int32 j2, int32 j3, int32 &i0, int32 &i1)
void	GetTangent (TFunctionRef< TVector2< RealType >(int32)> GetPointFunc, TArray< int32 > &Merged, int32 j0, int32 j1, int32 j2, int32 j3, int32 &i0, int32 &i1)

Protected Attributes
int32	Dimension = 0
int32	NumUniquePoints = 0
TArray< int32 >	Hull

Member Function Documentation

Empty()

template<typename RealType >

void UE::Geometry::TConvexHull2< RealType >::Empty ( )

inline

Empty any previously-computed convex hull data. Frees the hull memory. Note: You do not need to call this before calling Solve() with new data.

GetDimension()

template<typename RealType >

int32 UE::Geometry::TConvexHull2< RealType >::GetDimension ( ) const

inline

Returns

Number of dimensions spanned by the input points.

GetHull()

template<class RealType >

void UE::Geometry::TConvexHull2< RealType >::GetHull ( TFunctionRef< TVector2< RealType >(int32)>  GetPointFunc, TArray< int32 > &  Merged, int32 &  IdxFirst, int32 &  IdxLast  )

protected

GetLine()

template<typename RealType >

TLine2< RealType > UE::Geometry::TConvexHull2< RealType >::GetLine ( TArrayView< const TVector2< RealType > >  Points ) const

inline

Returns

the line spanned by a collinear input. Only meaningful if GetDimension() == 1

GetNumUniquePoints()

template<typename RealType >

int32 UE::Geometry::TConvexHull2< RealType >::GetNumUniquePoints ( ) const

inline

Number of unique points considered by convex hull construction (excludes exact duplicate points and filtered-out points)

GetPolygonIndices()

template<typename RealType >

TArray< int32 > const & UE::Geometry::TConvexHull2< RealType >::GetPolygonIndices ( ) const

inline

Returns

the calculated polygon vertices, as indices into the point set passed to Solve()

GetTangent()

template<class RealType >

void UE::Geometry::TConvexHull2< RealType >::GetTangent ( TFunctionRef< TVector2< RealType >(int32)>  GetPointFunc, TArray< int32 > &  Merged, int32  j0, int32  j1, int32  j2, int32  j3, int32 &  i0, int32 &  i1  )

protected

IsSolutionAvailable()

template<typename RealType >

bool UE::Geometry::TConvexHull2< RealType >::IsSolutionAvailable ( ) const

inline

Returns

true if convex hull is available

Merge()

template<class RealType >

void UE::Geometry::TConvexHull2< RealType >::Merge ( TFunctionRef< TVector2< RealType >(int32)>  GetPointFunc, TArray< int32 > &  Merged, int32  j0, int32  j1, int32  j2, int32  j3, int32 &  i0, int32 &  i1  )

protected

Solve() [1/3]

template<class RealType >

bool UE::Geometry::TConvexHull2< RealType >::Solve	(	int32	NumPoints,
		TFunctionRef< TVector2< RealType >(int32)>	GetPointFunc,
		TFunctionRef< bool(int32)>	FilterFunc = [](int32 Idx) {return true;}
	)

Generate convex hull as long as input is not degenerate If input is degenerate, this will return false, and caller can call GetDimension() to determine whether the points were collinear, or all the same point

Parameters

NumPoints	Number of points to consider
GetPointFunc	Function providing array-style access into points
FilterFunc	Optional filter to include only a subset of the points in the output hull

Returns

true if hull was generated, false if points span < 2 dimensions

Solve() [2/3]

template<typename RealType >

bool UE::Geometry::TConvexHull2< RealType >::Solve ( TArrayView< const TVector2< RealType > >  Points )

inline

Generate convex hull as long as input is not degenerate If input is degenerate, this will return false, and caller can call GetDimension() to determine whether the points were collinear, or all the same point

Parameters

Points

Array of points to consider

Returns

true if hull was generated, false if points span < 2 dimensions

Solve() [3/3]

template<typename RealType >

bool UE::Geometry::TConvexHull2< RealType >::Solve ( TArrayView< const TVector2< RealType > >  Points, TFunctionRef< bool(int32)>  FilterFunc  )

inline

Generate convex hull as long as input is not degenerate If input is degenerate, this will return false, and caller can call GetDimension() to determine whether the points were collinear, or all the same point

Parameters

Points	Array of points to consider
Filter	Optional filter to include only a subset of the points in the output hull

Returns

true if hull was generated, false if points span < 2 dimensions

SolveSimplePolygon()

template<typename RealType >

bool UE::Geometry::TConvexHull2< RealType >::SolveSimplePolygon	(	int32	NumPolygonPoints,
		TFunctionRef< TVector2< RealType >(int32)>	GetPointFunc,
		bool	bIsKnownCCW = false
	)

Generate convex hull for a simple polygon If input has fewer than 3 points, will return false If input is not a simple polygon (e.g. if it has self-intersections), may not find a correct hull

Parameters

NumPolygonPoints	Number of points in the polygon
GetPointFunc	Function providing array-style access into the polygon points
bIsKnownCCW	If true, will save some processing time by assuming input is wound counter-clockwise

Returns

true if a hull was generated

Member Data Documentation

Dimension

template<typename RealType >

int32 UE::Geometry::TConvexHull2< RealType >::Dimension = 0

protected

Hull

template<typename RealType >

TArray<int32> UE::Geometry::TConvexHull2< RealType >::Hull

protected

NumUniquePoints

template<typename RealType >

int32 UE::Geometry::TConvexHull2< RealType >::NumUniquePoints = 0

protected

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

• Engine/Source/Runtime/GeometryCore/Public/CompGeom/ConvexHull2.h
• Engine/Source/Runtime/GeometryCore/Private/CompGeom/ConvexHull2.cpp