DGtal  1.5.beta
Public Types | Public Member Functions | Static Public Attributes | Private Attributes
DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger > Class Template Reference

Aim: Class that implements an orientation functor, ie. it provides a way to compute the orientation of three given 2d points. More precisely, it returns: More...

#include <DGtal/geometry/tools/determinant/InHalfPlaneBySimple3x3Matrix.h>

Inheritance diagram for DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >:
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Public Types

typedef TPoint Point
 
typedef std::array< Point, 2 > PointArray
 
typedef PointArray::size_type SizeArray
 
typedef TInteger Integer
 
typedef SimpleMatrix< Integer, 3, 3 > Matrix
 
typedef Integer Value
 

Public Member Functions

 BOOST_CONCEPT_ASSERT ((concepts::CEuclideanRing< Integer >))
 
void init (const Point &aP, const Point &aQ)
 
void init (const PointArray &aA)
 
Value operator() (const Point &aR) const
 
void selfDisplay (std::ostream &out) const
 
bool isValid () const
 

Static Public Attributes

static const SizeArray size = 2
 

Private Attributes

Matrix myMatrix
 

Detailed Description

template<typename TPoint, typename TInteger>
class DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >

Aim: Class that implements an orientation functor, ie. it provides a way to compute the orientation of three given 2d points. More precisely, it returns:

  • zero if the three points belong to the same line
  • strictly positive if the three points are counter-clockwise oriented
  • striclty negative if the three points are clockwise oriented. The orientation test is performed by the evaluation of the determinant of a 3x3 matrix stored into an instance of SimpleMatrix.

Basic usage:

...
typedef Z2i::Point Point;
typedef InHalfPlaneBySimple3x3Matrix<Point, Z2i::Integer> MyType;
MyType orientationTest;
orientationTest.init( Point(0,0), Point(5,2) );
return orientationTest( Point(2,1) );
//a strictly positive value is returned because (0,0) (5,2) (2,1) are CCW oriented
DGtal::Z2i::Point
Space::Point Point
Definition: StdDefs.h:95
Template Parameters
TPointa model of point
TIntegera model of integer for the 3x3 matrix entries and the result, at least a model of CEuclideanRing

NB. In order to be sure that the result will be exact, you should be sure that TInteger can represent integers with 2b+3 bits if the points coordinates are coded with b bits.

See also
SimpleMatrix
InHalfPlaneBy2x2DetComputer

Definition at line 91 of file InHalfPlaneBySimple3x3Matrix.h.

Member Typedef Documentation

◆ Integer

template<typename TPoint , typename TInteger >
typedef TInteger DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::Integer

Type of matrix integral entries

NB: the type of the points coordinates are casted into Integer before being stored into the matrix.

Definition at line 120 of file InHalfPlaneBySimple3x3Matrix.h.

◆ Matrix

template<typename TPoint , typename TInteger >
typedef SimpleMatrix<Integer, 3, 3> DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::Matrix

Type of matrix

Definition at line 126 of file InHalfPlaneBySimple3x3Matrix.h.

◆ Point

template<typename TPoint , typename TInteger >
typedef TPoint DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::Point

Type of points

Definition at line 99 of file InHalfPlaneBySimple3x3Matrix.h.

◆ PointArray

template<typename TPoint , typename TInteger >
typedef std::array<Point,2> DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::PointArray

Type of point array

Definition at line 104 of file InHalfPlaneBySimple3x3Matrix.h.

◆ SizeArray

template<typename TPoint , typename TInteger >
typedef PointArray::size_type DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::SizeArray

Type used to represent the size of the array

Definition at line 108 of file InHalfPlaneBySimple3x3Matrix.h.

◆ Value

template<typename TPoint , typename TInteger >
typedef Integer DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::Value

Type of integer for the result

Definition at line 131 of file InHalfPlaneBySimple3x3Matrix.h.

Member Function Documentation

◆ BOOST_CONCEPT_ASSERT()

template<typename TPoint , typename TInteger >
DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::BOOST_CONCEPT_ASSERT ( (concepts::CEuclideanRing< Integer >)  )

◆ init() [1/2]

template<typename TPoint , typename TInteger >
void DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::init ( const Point &  aP,
const Point &  aQ 
)

Initialisation. The first two column vectors are stored into myMatrix

Parameters
aPfirst point
aQsecond point

◆ init() [2/2]

template<typename TPoint , typename TInteger >
void DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::init ( const PointArray &  aA)

Initialisation. The first two column vectors are stored into myMatrix

Parameters
aAarray of two points

◆ isValid()

template<typename TPoint , typename TInteger >
bool DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::isValid ( ) const

Checks the validity/consistency of the object.

Returns
'true' if the object is valid, 'false' otherwise.

◆ operator()()

template<typename TPoint , typename TInteger >
Value DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::operator() ( const Point &  aR) const

Main operator.

Warning
InHalfPlaneBy2x2DetComputer::init() should be called before
Parameters
aRany point to test
Returns
orientation of the three points aP aQ aR :
  • zero if the three points belong to the same line
  • strictly positive if the three points are counter-clockwise oriented
  • striclty negative if the three points are clockwise oriented
See also
InHalfPlaneBy2x2DetComputer::init()

◆ selfDisplay()

template<typename TPoint , typename TInteger >
void DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::selfDisplay ( std::ostream &  out) const

Writes/Displays the object on an output stream.

Parameters
outthe output stream where the object is written.

Field Documentation

◆ myMatrix

template<typename TPoint , typename TInteger >
Matrix DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::myMatrix
mutableprivate

3x3 matrix whose determinant provides the expected result

Definition at line 179 of file InHalfPlaneBySimple3x3Matrix.h.

◆ size

template<typename TPoint , typename TInteger >
const SizeArray DGtal::InHalfPlaneBySimple3x3Matrix< TPoint, TInteger >::size = 2
static

static size of the array, ie. 2

Definition at line 112 of file InHalfPlaneBySimple3x3Matrix.h.

The documentation for this class was generated from the following file: