Aim: This concept gathers classes that are able to compare the position of two given points \( P, Q \) around a pole \( O \). More precisely, they compare the oriented angles lying between the horizontal line passing by \( O \) and the rays \( [OP) \) and \( [OQ) \) (in a counter-clockwise orientation). This is equivalent to compare the angle in radians from 0 (included) to 2 π (excluded). More...

#include <DGtal/geometry/tools/CPolarPointComparator2D.h>

Inheritance diagram for DGtal::concepts::CPolarPointComparator2D< T >:

[legend]

Public Types
typedef T::Point	Point

Public Member Functions
	BOOST_CONCEPT_USAGE (CPolarPointComparator2D)
void	checkConstConstraints () const

Private Attributes
T	myX
Point	myP
bool	myB

Detailed Description

template<typename T>
struct DGtal::concepts::CPolarPointComparator2D< T >

Aim: This concept gathers classes that are able to compare the position of two given points \( P, Q \) around a pole \( O \). More precisely, they compare the oriented angles lying between the horizontal line passing by \( O \) and the rays \( [OP) \) and \( [OQ) \) (in a counter-clockwise orientation). This is equivalent to compare the angle in radians from 0 (included) to 2 π (excluded).

Description of concept 'CPolarPointComparator2D'

The main method is the operator() applied on two points. It returns 'true' if the first point is located strictly before the second one, 'false' otherwise. A point \( P \) is located strictly before a point \( Q \) iff the oriented angle done by \( P \) is smaller than the one of \( Q \) or its euclidean norm is shorter if \( O, P, Q \) are aligned. Note that it returns 'false' if \( P = Q \).

Refinement of default constructible, copy constructible, assignable

Associated types

Point : type of points

Notation

X : A type that is a model of CPolarPointComparator2D
x : object of type X
P : type of points
p, p1, p2 : objects type P

Definitions

Valid expressions and semantics

Models

PolarPointComparator2DBy2x2DetComputer.

Template Parameters

T	the type that should be a model of CPolarPointComparator2D.

Definition at line 96 of file CPolarPointComparator2D.h.

Member Typedef Documentation

◆ Point

template<typename T>

typedef T::Point DGtal::concepts::CPolarPointComparator2D< T >::Point

Definition at line 101 of file CPolarPointComparator2D.h.

Member Function Documentation

◆ BOOST_CONCEPT_USAGE()

template<typename T>

DGtal::concepts::CPolarPointComparator2D< T >::BOOST_CONCEPT_USAGE ( CPolarPointComparator2D< T > )

inline

Definition at line 103 of file CPolarPointComparator2D.h.

    {
      myX.setPole( myP ); 
 
      checkConstConstraints();
    }

References checkConstConstraints(), myP, and myX.

◆ checkConstConstraints()

template<typename T>

void DGtal::concepts::CPolarPointComparator2D< T >::checkConstConstraints ( ) const

inline

Definition at line 109 of file CPolarPointComparator2D.h.

    {
      // const method dummyConst should take parameter myA of type A and return
      // something of type B
      concepts::ConceptUtils::sameType( myB, myX( myP, myP ) );
    }