RandomPolygonTraits_2 Concept Reference

Definition

The concept RandomPolygonTraits_2 describes the requirements for the traits class used by the function random_polygon_2().

Has Models:

CGAL kernels.

Operations

The following two member functions returning instances of the above predicate object types are required.

Types
typedef unspecified_type	FT
	The coordinate type of the points of the polygon.
typedef unspecified_type	Point_2
	The point type of the polygon.
typedef unspecified_type	Orientation_2
	Predicate object type that determines the orientation of three points.
typedef unspecified_type	Less_xy_2
	Binary predicate object type comparing Point_2s lexicographically.

Operations
Less_xy_2	less_xy_2_object ()
Orienation_2	orientation_2_object ()

Member Typedef Documentation

Less_xy_2

typedef unspecified_type RandomPolygonTraits_2::Less_xy_2

Binary predicate object type comparing Point_2s lexicographically.

It must provide bool operator()(Point_2 p, Point_2 q) that returns true 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 the \( x\) and \( y\) coordinates of point \( p\), resp.

Orientation_2

typedef unspecified_type RandomPolygonTraits_2::Orientation_2

Predicate object type that determines the orientation of three points.

It must provide Orientation operator()(Point_2 p, Point_2 q, Point_2 r) that returns LEFT_TURN, if \( r\) lies to the left of the oriented line \( l\) defined by \( p\) and \( q\), returns RIGHT_TURN if \( r\) lies to the right of \( l\), and returns COLLINEAR if \( r\) lies on \( l\).