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fl::Point Class Reference

#include <point.h>

Inheritance diagram for fl::Point:

List of all members.

Public Methods
	Point ()
	Point (float x, float y)
template<class T>	Point (const MatrixAbstract< T > &A)
	Point (std::istream &stream)
Vector< float >	homogenous (float third) const
Vector< float >	homogenous (float third, float fourth) const
virtual float &	operator() (const int row, const int column) const
	Element accesss.
virtual float &	operator[] (const int row) const
	Element access, treating us as a vector.
virtual int	rows () const
virtual int	columns () const
virtual MatrixAbstract< float > *	duplicate () const
	Make a new instance of self on the heap, with shallow copy semantics. Used for views. Since this is class sensitive, it must be overridden.
virtual void	resize (const int rows, const int columns=1)
	We only have one size. This will throw an exception if (rows * columns) != 2.
virtual void	read (std::istream &stream)
virtual void	write (std::ostream &stream, bool withName=false)
	withName is ignored, and no class id is ever written for Points
float	distance (const Point &that) const
	Euclidean distance between two points.
float	distance () const
	Euclidean distance from origin.
float	angle (const Point &that) const
	Determines angle of vector (that - this).
float	angle () const
	Determines angle of vector from origin to this point.
Public Attributes
float	x
float	y

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Detailed Description

A point in a pixel raster.

Point uses float values for x and y, so we define the following convention for interpreting the fractional part of a pixel coordinate: The image coordinate system starts in the upper left corner. Positive x goes to the right, and positive y goes down. Integer pixel coordinates (eg: 0, 1.0, 2.0, etc.) refer to the center of the pixel. IE: a pixel begins at -0.5 and ends at 0.5. This convention allows easy conversion between ints and floats that is also geometrically consistent and valid. The only thing it makes more difficult is determining the edges and center of an image, usually one-time calculations.

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Constructor & Destructor Documentation

Point::Point (    )

Point::Point (  float    x, float    y )

template<class T> fl::Point::Point (  const MatrixAbstract< T > &    A )  [inline]

Point::Point (  std::istream &    stream )

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Member Function Documentation

float Point::angle (    )

Determines angle of vector from origin to this point.

float Point::angle (  const Point &    that )  const

Determines angle of vector (that - this).

int Point::columns (    )  [virtual]

Reimplemented from fl::MatrixAbstract< float >.

float Point::distance (    )

Euclidean distance from origin.

float Point::distance (  const Point &    that )  const

Euclidean distance between two points.

MatrixAbstract< float > * Point::duplicate (    )  const [virtual]

Make a new instance of self on the heap, with shallow copy semantics. Used for views. Since this is class sensitive, it must be overridden. Implements fl::MatrixAbstract< float >.

Vector< float > Point::homogenous (  float    third, float    fourth )  const

Vector< float > Point::homogenous (  float    third )  const

virtual float& fl::Point::operator() (  const int    row, const int    column )  const [inline, virtual]

Element accesss. Implements fl::MatrixAbstract< float >.

virtual float& fl::Point::operator[] (  const int    row )  const [inline, virtual]

Element access, treating us as a vector. Reimplemented from fl::MatrixAbstract< float >.

void Point::read (  std::istream &    stream )  [virtual]

Reimplemented from fl::MatrixAbstract< float >. Reimplemented in fl::PointInterest, and fl::PointAffine.

void Point::resize (  const int    rows, const int    columns = 1 )  [virtual]

We only have one size. This will throw an exception if (rows * columns) != 2. Implements fl::MatrixAbstract< float >.

int Point::rows (    )  [virtual]

Reimplemented from fl::MatrixAbstract< float >.

void Point::write (  std::ostream &    stream, bool    withName = false )  [virtual]

withName is ignored, and no class id is ever written for Points Reimplemented in fl::PointInterest, and fl::PointAffine.

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Member Data Documentation

float fl::Point::x

float fl::Point::y

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

• point.h
• Point.cc

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