PolylineSimplificationCostFunction Concept Reference

Definition

Models of this concept are passed to the polyline simplification algorithm to calculate the cost of removing a vertex. Such a cost represents some measure of the deviation error between the polyline sets before and after removal. The smaller the error the lower the cost. The algorithm processes vertices in increasing cost order to preserve the overall polyline set shape as much as possible.

Refines

CopyConstructible

Assignable

Has models

CGAL::Polyline_simplification_2::Hybrid_squared_distance_cost

CGAL::Polyline_simplification_2::Scaled_squared_distance_cost

CGAL::Polyline_simplification_2::Squared_distance_cost

Public Member Functions
template<typename CDT >
std::optional< CDT::Geom_traits::FT >	operator() (CGAL::Constrained_triangulation_plus_2< CDT > const &ct, CGAL::Constrained_triangulation_plus_2< CDT >::Vertices_in_constraint_iterator viq) const
	Given a vertex in constraint iterator viq computes vip=std::prev(viq) and vir=std::next(vir), and the cost of removing vertex *viq, replacing edges (*vip,*viq) and (*viq,*vir) with edge (*vip,*vir).

Member Function Documentation

operator()()

template<typename CDT >

std::optional< CDT::Geom_traits::FT > PolylineSimplificationCostFunction::operator()	(	CGAL::Constrained_triangulation_plus_2< CDT > const &	ct,
		CGAL::Constrained_triangulation_plus_2< CDT >::Vertices_in_constraint_iterator	viq
	)		const

Given a vertex in constraint iterator viq computes vip=std::prev(viq) and vir=std::next(vir), and the cost of removing vertex *viq, replacing edges (*vip,*viq) and (*viq,*vir) with edge (*vip,*vir).

Parameters

ct	The underlying constrained Delaunay triangulation which embeds the polyline constraints
viq	The vertex in constraint iterator of the vertex to remove

Returns

The cost for removing *viq. The value std::nullopt can be returned to indicate an infinite or uncomputable cost.

Template Parameters

CDT	must be CGAL::Constrained_triangulation_plus_2 with a vertex type that is model of PolylineSimplificationVertexBase_2. CDT::Geom_traits must be model of the concept ConstrainedDelaunayTriangulationTraits_2.