IsYMonotoneTraits_2 Concept Reference

Definition

Requirements of a traits class to be used with the function is_y_monotone_2() that tests whether a sequence of 2D points defines a \( y\)-monotone polygon or not.

Has models

CGAL::Partition_traits_2<R>

CGAL::Kernel_traits_2

See also

CGAL::Is_y_monotone_2<Traits>

CGAL::y_monotone_partition_2()

CGAL::y_monotone_partition_is_valid_2()

Types
The following two types are required:
typedef unspecified_type	Point_2
	The point type of the polygon vertices.
typedef unspecified_type	Less_yx_2
	Predicate object type that compares Point_2s lexicographically.

Creation
Only a copy constructor is required.
	IsYMonotoneTraits_2 (IsYMonotoneTraits_2 tr)

Operations
The following function that creates an instance of the above predicate object type must exist:
Less_yx_2	less_yx_2_object ()

Member Typedef Documentation

Less_yx_2

typedef unspecified_type IsYMonotoneTraits_2::Less_yx_2

Predicate object type that compares Point_2s lexicographically.

Must provide bool operator()(Point_2 p, Point_2 q) where true is returned iff \( p <_{xy} q\). We have \( p<_{xy}q\), iff \( p_x < q_x\) or \( p_x = q_x\) and \( p_y < q_y\), where \( p_x\) and \( p_y\) denote \( x\) and \( y\) coordinate of point \( p\) resp.