SpatialSortingTraits_2 Concept Reference

Definition

All 2D spatial sorting algorithms provided in CGAL are parameterized by a traits class Traits, which defines the primitives (objects and predicates) that the sorting algorithms use. SpatialSortingTraits_2 defines the complete set of primitives required in these functions and functors.

Has Models:

Any CGAL kernel.

CGAL::Spatial_sort_traits_adapter_2<Base_traits,PointPropertyMap>

Types
typedef unspecified_type	Point_2
	The point type on which the sorting algorithms operate.
typedef unspecified_type	Compute_x_2
	Functor object type returning the \( x\) coordinate of a Point_2.
typedef unspecified_type	Compute_y_2
	Functor object type returning the \( y\) coordinate of a Point_2.
typedef unspecified_type	Less_x_2
	Binary predicate object type comparing Point_2s along the \( x\) coordinate.
typedef unspecified_type	Less_y_2
	Binary predicate object type comparing Point_2s along the \( y\) coordinate.

Creation
Only a copy constructor is required.
	SpatialSortingTraits_2 (const SpatialSortingTraits_2 &t)

Operations
The following member functions to create instances of the above predicate object types must exist.
Compute_x_2	compute_x_2_object ()
Compute_y_2	compute_y_2_object ()
Less_x_2	less_x_2_object ()
Less_y_2	less_y_2_object ()

Member Typedef Documentation

Compute_x_2

typedef unspecified_type SpatialSortingTraits_2::Compute_x_2

Functor object type returning the \( x\) coordinate of a Point_2.

Must provide FT operator()(Point_2 p) where FT can be used as argument of CGAL::to_double.

Compute_y_2

typedef unspecified_type SpatialSortingTraits_2::Compute_y_2

Functor object type returning the \( y\) coordinate of a Point_2.

Must provide FT operator()(Point_2 p) where FT can be used as argument of CGAL::to_double.

Less_x_2

typedef unspecified_type SpatialSortingTraits_2::Less_x_2

Binary predicate object type comparing Point_2s along the \( x\) coordinate.

Must provide bool operator()(Point_2 p, Point_2 q) where true is returned iff \( p_x < q_x\), where \( p_x\) and \( q_x\) denote \( x\) coordinate of point \( p\) and \( q\), respectively.

Less_y_2

typedef unspecified_type SpatialSortingTraits_2::Less_y_2

Binary predicate object type comparing Point_2s along the \( y\) coordinate.

Must provide bool operator()(Point_2 p, Point_2 q) where true is returned iff \( p_y < q_y\), where \( p_y\) and \( q_y\) denote \( y\) coordinate of point \( p\) and \( q\), respectively.