CGAL::Rotational_sweep_visibility_2< Arrangement_2_, RegularizationCategory > Class Template Reference

#include <CGAL/Rotational_sweep_visibility_2.h>

Definition

template<typename Arrangement_2_, typename RegularizationCategory = Tag_true>
class CGAL::Rotational_sweep_visibility_2< Arrangement_2_, RegularizationCategory >

This class is a model of the concept Visibility_2 can answer visibility queries within a polygon that may have holes.

The algorithm does not require preprocessing. It relies on the algorithm of T. Asano [1] based on angular plane sweep, with a time complexity of \(O(n \log n)\) in the number of vertices.

Template Parameters

Arrangement_2_	is the type used to represent the input environment. It must be an instance of CGAL::Arrangement_2, where its CGAL::Arrangement_2::Traits_2 must be an instance of CGAL::Arr_segment_traits_2, or of CGAL::Arr_non_caching_segment_traits_2.
RegularizationCategory	indicates whether the output should be regularized. It can be specified by one of the following: #Tag_true or #Tag_false, where #Tag_false is the default value.

Is model of

Visibility_2

See also

CGAL::Simple_polygon_visibility_2

CGAL::Triangular_expansion_visibility_2

Types
typedef Arrangement_2	Arrangement_2
	The type of the input arrangement.

Tags
typedef RegularizationCategory	Regularization_category
	identifies whether the regularized visibility area is computed (either #Tag_true or #Tag_false).
typedef Tag_true	Supports_general_polygon_category
	See Visibility_2::Supports_general_polygon_category.
typedef Tag_true	Supports_simple_polygon_category
	See Visibility_2::Supports_simple_polygon_category.

Functions
void	attach (const Arrangement_2 &arr)
	Attaches the given arrangement to the visibility object.

Member Typedef Documentation

Regularization_category

template<typename Arrangement_2_ , typename RegularizationCategory = Tag_true>

typedef RegularizationCategory CGAL::Rotational_sweep_visibility_2< Arrangement_2_, RegularizationCategory >::Regularization_category

identifies whether the regularized visibility area is computed (either #Tag_true or #Tag_false).

Member Function Documentation

attach()

template<typename Arrangement_2_ , typename RegularizationCategory = Tag_true>

void CGAL::Rotational_sweep_visibility_2< Arrangement_2_, RegularizationCategory >::attach

(

const Arrangement_2 &

arr

)

Attaches the given arrangement to the visibility object.

This operation takes \(O(1)\) as the class does no preprocessing.

In case the object is already attached to another arrangement, the visibility object gets detached before being attached to arr.