CGAL 5.4  2D Arrangements

A model of the ArrangementPointLocation_2
concept can answer pointlocation queries on an arrangement attached to it. Namely, given a Arrangement_2::Point_2
object, representing a point in the plane, it returns the arrangement cell containing it. In the general case, the query point is contained inside an arrangement face, but in degenerate situations it may lie on an edge or coincide with an arrangement vertex.
A note on Backwards compatibility
The locate
member function used to return CGAL::Object
up to CGAL version 4.2. Starting with CGAL version 4.3 the return type is determined by a metafunction. To preserve backwards compatibility CGAL::Object
can be constructed from the new return types implicitly, but switching to the new style is recommended. To enable the old style without any overhead, the macro CGAL_ARR_POINT_LOCATION_VERSION
can be defined to 1 before any CGAL header is included.
CGAL::Arr_naive_point_location<Arrangement>
CGAL::Arr_walk_along_line_point_location<Arrangement>
CGAL::Arr_trapezoid_ric_point_location<Arrangement>
CGAL::Arr_landmarks_point_location<Arrangement,Generator>
CGAL::Arr_naive_point_location<Arrangement>
CGAL::Arr_walk_along_line_point_location<Arrangement>
CGAL::Arr_trapezoid_ric_point_location<Arrangement>
CGAL::Arr_landmarks_point_location<Arrangement,Generator>
CGAL::Arr_point_location_result<Arrangement>
CGAL_ARR_POINT_LOCATION_VERSION
Types  
typedef unspecified_type  Arrangement_2 
the associated arrangement type.  
typedef unspecified_type  Point_2 
equivalent to Arrangement_2::Point_2 .  
Creation  
ArrangementPointLocation_2 ()  
default constructor.  
ArrangementPointLocation_2 (const Arrangement_2 &arr)  
constructs a pointlocation object pl attached to the given arrangement arr .  
Query Functions  
Arr_point_location_result< Arrangement_2 >::Type  locate (const Point_2 &q) const 
locates the arrangement cell that contains the query point q and returns a discriminated union container of the following bounded types: More...  
Operations  
void  attach (const Arrangement_2 &arr) 
attaches pl to the given arrangement arr .  
void  detach () 
detaches pl from the arrangement it is currently attached to.  
Arr_point_location_result<Arrangement_2>::Type ArrangementPointLocation_2::locate  (  const Point_2 &  q  )  const 
locates the arrangement cell that contains the query point q
and returns a discriminated union container of the following bounded types:
Arrangement_2::Face_const_handle
, in case q
is contained inside an arrangement face; Arrangement_2::Halfedge_const_handle
, in case q
lies on an arrangement edge; Arrangement_2::Vertex_const_handle
, in case q
coincides with an arrangement vertex. pl
is attached to a valid arrangement object.