CGAL 5.0.2 - 2D Polygon Partitioning
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

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. More...

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 ()

◆ 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.