mln::Point_Site< E > Struct Template Reference

Base class for implementation classes of the notion of "point site". More...

#include <point_site.hh>

Inheritance diagram for mln::Point_Site< E >:

List of all members.

Related Functions
(Note that these are not member functions.)
template<typename L, typename R>
L::dpoint	operator- (const Point_Site< L > &lhs, const Point_Site< R > &rhs)
	Difference between a couple of point site lhs and rhs.
template<typename P>
std::ostream &	operator<< (std::ostream &ostr, const Point_Site< P > &p)
	Print a point site p into the output stream ostr.
template<typename L, typename R>
bool	operator== (const Point_Site< L > &lhs, const Point_Site< R > &rhs)
	Equality comparison between a couple of point site lhs and rhs.
template<typename P, typename D>
P::point	operator+ (const Point_Site< P > &p, const Delta_Point_Site< D > &dp)
	Add a delta-point rhs to a point site lhs.
template<typename P, typename D>
P::point	operator- (const Point_Site< P > &p, const Delta_Point_Site< D > &dp)
	}

---

Detailed Description

template<typename E>
struct mln::Point_Site< E >

Base class for implementation classes of the notion of "point site".

A point site ("psite" for short) is an object that allows an efficient access to data associated with a point. A point site is either a point or designates a point.

When a point site is not really a point, it is automatically convertible to the point it designates.

Let us take the example of a 2D image encoded as an array of runs of values. With a point, a pair (row index, column index), retrieving the corresponding pixel value would mean to browse the array of runs to find the value location. That would not be efficient. Conversely, a point site dedicated to this image structure allows for value access in contant time; precisely the proper point site is a pair (index of run, index within the run).

---

Friends And Related Function Documentation

template<typename P, typename D>

P::point operator+	(	const Point_Site< P > &	p,
		const Delta_Point_Site< D > &	dp
	)			[related]

Add a delta-point rhs to a point site lhs.

Parameters:

[in]	p	A point site.
[in]	dp	A delta-point.

The type of dp has to compatible with the type of p.

Returns:

A point (temporary object).

See also:

mln::Delta_Point_Site

template<typename P, typename D>

P::point operator-	(	const Point_Site< P > &	p,
		const Delta_Point_Site< D > &	dp
	)			[related]

}

Substract a delta-point dp to a point site p.

Parameters:

[in]	p	A point site.
[in]	dp	A delta-point.

The type of dp has to compatible with the type of p.

Returns:

A point (temporary object).

See also:

mln::Dpoint

mln::Delta_Point_Site

template<typename L, typename R>

L::dpoint operator-	(	const Point_Site< L > &	lhs,
		const Point_Site< R > &	rhs
	)			[related]

Difference between a couple of point site lhs and rhs.

Parameters:

[in]	lhs	A first point site.
[in]	rhs	A second point site.

Warning:

There is no type promotion in Milena so the client has to make sure that both points are defined with the same type of coordinates.

Precondition:

Both lhs and rhs have to be defined on the same topology and with the same type of coordinates; otherwise this test does not compile.

Postcondition:

The result, dp, is such as lhs == rhs + dp.

Returns:

A delta point (temporary object).

See also:

mln::Delta_Point_Site

template<typename P>

std::ostream & operator<<	(	std::ostream &	ostr,
		const Point_Site< P > &	p
	)			[related]

Print a point site p into the output stream ostr.

Parameters:

[in,out]	ostr	An output stream.
[in]	p	A point site.

Returns:

The modified output stream ostr.

template<typename L, typename R>

bool operator==	(	const Point_Site< L > &	lhs,
		const Point_Site< R > &	rhs
	)			[related]

Equality comparison between a couple of point site lhs and rhs.

Parameters:

[in]	lhs	A first point site.
[in]	rhs	A second point site.

Precondition:

Both lhs and rhs have to be defined on the same topology; otherwise this test does not compile.

Returns:

True if both point sites have the same coordinates, otherwise false.