\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.12.1 - 2D Polyline Simplification
CGAL::Polyline_simplification_2::Hybrid_squared_distance_cost< FT > Class Template Reference

#include <CGAL/Polyline_simplification_2/Hybrid_squared_distance_cost.h>

Definition

This class is a cost function which calculates the cost as the square of the distance between the original and simplified polylines, possibly scaled based on a factor.

Is Model Of:
PolylineSimplificationCostFunction.

Public Member Functions

 Hybrid_squared_distance_cost (FT ratio)
 Initializes the cost function with the specified ratio
 
template<class CDT >
boost::optional< typename CDT::Geom_traits::FT > operator() (const Constrained_triangulation_plus_2< CDT > &pct, typename Constrained_triangulation_plus_2< CDT >::Vertices_in_constraint_iterator vicq) const
 Compute the hybrid squared distance cost. More...
 

Member Function Documentation

◆ operator()()

template<class FT >
template<class CDT >
boost::optional<typename CDT::Geom_traits::FT> CGAL::Polyline_simplification_2::Hybrid_squared_distance_cost< FT >::operator() ( const Constrained_triangulation_plus_2< CDT > &  pct,
typename Constrained_triangulation_plus_2< CDT >::Vertices_in_constraint_iterator  vicq 
) const

Compute the hybrid squared distance cost.

Given a vertex in constraint iterator vicq computes vicp=std::prev(vicq) and vicr=std::next(vicq), returns the maximal square distance between each point along the original subpolyline, between vicp and vicr, and the straight line segment from *vicp->point() to *vicr->point() divided by the smallest of

  • the square of the ratio given to the constructor of the cost function,
  • and the shortest squared distance between that segment and each of the vertices adjacent to vicq.
Template Parameters
CDTmust be CGAL::Constrained_Delaunay_triangulation_2 with a vertex type that is model of PolylineSimplificationVertexBase_2.