lti::tline< T > Class Template Reference
[Geometry Data Structures]

Type for computations with lines. More...

#include <ltiLine.h>

Inheritance diagram for lti::tline< T >:

[legend]

List of all members.

Public Member Functions
	tline ()
	tline (const tpoint< T > &theStart, const tpoint< T > &theEnd)
template<class U >
	tline (const tline< U > &other)
template<class U >
tline< T > &	castFrom (const tline< U > &other)
void	set (const tpoint< T > &theStart, const tpoint< T > &theEnd)
void	setStart (const tpoint< T > &theStart)
void	setEnd (const tpoint< T > &theEnd)
void	invert ()
const tpoint< T > &	getStart () const
const tpoint< T > &	getEnd () const
tline< T > &	copy (const tline< T > &other)
tline< T > &	operator= (const tline< T > &other)
bool	operator== (const tline< T > &other) const
bool	operator!= (const tline< T > &other) const
Distance computation
T	distanceTo (const tpoint< T > &c) const
T	distanceSqr (const tpoint< T > &c) const
T	distanceSqr (const tpoint< T > &c, tpoint< T > &p) const
T	distanceToXPol (const tpoint< T > &c) const
T	distanceSqrXPol (const tpoint< T > &c) const
T	distanceSqrXPol (const tpoint< T > &c, tpoint< T > &p) const
T	sqrLength () const
Intersections
bool	doesIntersect (const tline< T > &other) const
bool	isParallel (const tline< T > &other) const
bool	isColinear (const tline< T > &other) const
bool	intersect (const trectangle< T > &rect)
bool	intersect (const tline< T > &other, const trectangle< T > &rect)
template<class U >
bool	getIntersectionPoint (const tline< T > &other, tpoint< U > &p, bool &colinear) const
bool	getCommonLine (const tline< T > &other)
bool	getCommonLine (const tline< T > &first, const tline< T > &second)
bool	doesPointIntersectXPol (const tline< T > &other) const
template<class U >
bool	getIntersectionPointXPol (const tline< T > &other, tpoint< U > &p, bool &onThisLine, bool &onOtherLine, bool &colinear) const
template<class U >
bool	getIntersectionPointXPol (const tline< T > &other, tpoint< U > &p) const
bool	intersectXPol (const trectangle< T > &rect)
bool	intersectXPol (const tline< T > &other, const trectangle< T > &rect)
Scaling and Translation operations
template<class U >
tline< T > &	scale (const U c)
template<class U >
tline< T >	operator* (const U c) const
template<class U >
tline< T > &	operator*= (const U c)
template<class U >
tline< T > &	divide (const U c)
template<class U >
tline< T >	operator/ (const U c) const
template<class U >
tline< T > &	operator/= (const U c)
tline< T > &	translate (const tpoint< T > &p)
tline< T > &	translate (const tline< T > &other, const tpoint< T > &p)
tline< T > &	getOrthogonal (double offset)
tline< T > &	getOrthogonal (const tline< T > &other, double offset)
Protected Attributes
tpoint< T >	start
tpoint< T >	end

---

Detailed Description

template<class T>
class lti::tline< T >

Type for computations with lines.

A line (or more generally a tline<T>) is represented by a start point and an end point.

The type T correspond to the coordinate type used in both points.

This class stores only the two points, and provides some functionality using them. Other operations can be achieved more efficiently if more information about the line, like its slope, is also stored. This is done by some derived classes.

---

Constructor & Destructor Documentation

template<class T>

lti::tline< T >::tline

(

)

[explicit]

default constructor.

Both points are left uninitialized (this can save some time)

template<class T>

lti::tline< T >::tline	(	const tpoint< T > &	theStart,
		const tpoint< T > &	theEnd
	)

constructor with both points

template<class T>

template<class U >

lti::tline< T >::tline

(

const tline< U > &

other

)

[inline]

copy constructor

---

Member Function Documentation

template<class T>

template<class U >

tline<T>& lti::tline< T >::castFrom

(

const tline< U > &

other

)

[inline]

cast operator

Reimplemented in lti::tfastLine< T >.

References lti::tline< T >::end, and lti::tline< T >::start.

template<class T>

tline<T>& lti::tline< T >::copy

(

const tline< T > &

other

)

[inline]

copy operator

Reimplemented in lti::tfastLine< T >.

Referenced by lti::tline< T >::operator=().

template<class T>

T lti::tline< T >::distanceSqr	(	const tpoint< T > &	c,
		tpoint< T > &	p
	)			const

Calculate minimal square of euclidian distance to the point c.

This method is faster than distanceTo (because it does not calculate the square root).

Parameters:

	c	point to which the minimal distance is searched.
	p	point in the line segment with the minimal distance to c.

Returns:

the square of the minimal distance to c

template<class T>

T lti::tline< T >::distanceSqr

(

const tpoint< T > &

c

)

const [inline]

Calculate minimal square of euclidian distance to the point c.

This method is faster than distanceTo (because it does not calculate the square root).

Parameters:

c

point to which the minimal distance is searched.

Returns:

the square of the minimal distance to c

template<class T>

T lti::tline< T >::distanceSqrXPol	(	const tpoint< T > &	c,
		tpoint< T > &	p
	)			const

Calculate square of distance to the point c to the infinite line (eXtraPolated) containing this line segment.

Parameters:

	c	point to which the minimal distance is searched.
	p	point in the extrapolated line segment with the minimal distance to c.

This method is faster than distanceToXPol (because it does not calculate the square root).

See also:

sqrDistanceTo()

Reimplemented in lti::tfastLine< T >.

template<class T>

T lti::tline< T >::distanceSqrXPol

(

const tpoint< T > &

c

)

const [inline]

Calculate square of distance to the point c to the infinite line (eXtraPolated) containing this line segment.

Parameters:

c

point to which the minimal distance is searched.

Returns:

the square of the minimal distance to c

See also:

sqrDistanceTo()

This method is faster than distanceToXPol (because it does not calculate the square root).

Reimplemented in lti::tfastLine< T >.

template<class T>

T lti::tline< T >::distanceTo

(

const tpoint< T > &

c

)

const [inline]

calculate minimal euclidian distance of the line segment to the point c.

This method is slower than the sqrDistanceTo, which avoids the computation of a (in many cases not required) square root.

See also:

sqrDistanceTo() distanceToXPol()

template<class T>

T lti::tline< T >::distanceToXPol

(

const tpoint< T > &

c

)

const [inline]

Calculate distance to the point c to the infinite line (eXtraPolated) containing this line segment.

Returns:

the minimal distance to c

Reimplemented in lti::tfastLine< T >.

template<class T>

template<class U >

tline<T>& lti::tline< T >::divide

(

const U

c

)

[inline]

divide both points by the given c factor

Reimplemented in lti::tfastLine< T >.

References lti::tline< T >::end, and lti::tline< T >::start.

Referenced by lti::tline< T >::operator/=().

template<class T>

bool lti::tline< T >::doesIntersect

(

const tline< T > &

other

)

const

Check if this line segment intersects the other given one.

Parameters:

other

the other line segment to which an intersection is going to be checked.

Returns:

true if both line segments intersect.

template<class T>

bool lti::tline< T >::doesPointIntersectXPol

(

const tline< T > &

other

)

const

Check if this infinitely extrapolated line intersects the other given infinite line at a single finite point.

Parameters:

other

the other line segment to which an intersection is going to be checked.

Returns:

true if both inifinite lines intersect at a single finite point.

This method can be overloaded in derived classes and other information to accellerate the computations.

template<class T>

bool lti::tline< T >::getCommonLine	(	const tline< T > &	first,
		const tline< T > &	second
	)			[inline]

Compute the common line segment between the given line segments.

This intersection is only going to be computed if both lines are colinear.

Parameters:

	first	first line segment.
	second	second line segment.

Returns:

true if a common line segment exists. It returns false otherwise. If both line segments are parallel and colinear, this method returns true and determines the line segment even if it is inifinitely small, i.e. a point.

The common line segment will be left in this instance.

This method can be overloaded in derived classes and other information to accellerate the computations.

template<class T>

bool lti::tline< T >::getCommonLine

(

const tline< T > &

other

)

Compute the common line segment between this line segment and the other given one and leave the result here.

This intersection is only going to be computed if both lines are colinear.

Parameters:

other

the other line segment to which the intersection is going to be computed.

Returns:

true if an common line segment exists. It returns false otherwise. If both line segments are parallel and colinear, this method returns true and determines the line segment even if it is inifinitely small, i.e. a point.

This method can be overloaded in derived classes and other information to accellerate the computations.

template<class T>

const tpoint<T>& lti::tline< T >::getEnd

(

)

const [inline]

return a read only reference to the end point

Referenced by lti::draw< rgbPixel >::line().

template<class T>

template<class U >

bool lti::tline< T >::getIntersectionPoint	(	const tline< T > &	other,
		tpoint< U > &	p,
		bool &	colinear
	)			const [inline]

Compute the intersection point of this line segment with the other given one.

Parameters:

	other	the other line segment to which the intersection point is going to be computed.
	p	if there is an intersection between both line segments the intersection point will be written here.
	colinear	this parameter is set to true in case both line segments are parallel and co-linear.

Returns:

true if an unique intersection point exists. It returns false otherwise. If both line segments are parallel and colinear, this method returns true and determines the intersection if the intersection is inifinitely small.

This method can be overloaded in derived classes and other information to accellerate the computations.

References lti::abs(), lti::condRoundCastTo(), lti::tline< T >::end, lti::tline< T >::start, lti::tpoint< T >::x, and lti::tpoint< T >::y.

template<class T>

template<class U >

bool lti::tline< T >::getIntersectionPointXPol	(	const tline< T > &	other,
		tpoint< U > &	p
	)			const [inline]

Compute the intersection point of this infinitely extrapolated line with the other given infinite line.

Parameters:

	other	the other line segment to which the intersection point is going to be computed.
	p	if there is an intersection between both line segments or between their respective infinite line extrapolations, the intersection point will be written here.

Returns:

true if an unique intersection point exists. It returns false otherwise.

This method can be overloaded in derived classes and other information to accellerate the computations.

References lti::condRoundCastTo(), lti::tline< T >::end, lti::tline< T >::start, lti::tpoint< T >::x, and lti::tpoint< T >::y.

template<class T>

template<class U >

bool lti::tline< T >::getIntersectionPointXPol	(	const tline< T > &	other,
		tpoint< U > &	p,
		bool &	onThisLine,
		bool &	onOtherLine,
		bool &	colinear
	)			const [inline]

Compute the intersection point of this infinitely extrapolated line with the other given infinite line.

Parameters:

	other	the other line segment to which the intersection point is going to be computed.
	p	if there is an intersection between both line segments or between their respective infinite line extrapolations, the intersection point will be written here.
	onThisLine	if the intersection occurs at a point on the line segment, this parameter will be set to true. Otherwise false.
	onOtherLine	if the intersection occurs at a point on the other line segment, this parameter will be set to true.
	colinear	this parameter is set to true in case both line segments are parallel and co-linear.

Returns:

true if an unique intersection point exists. It returns false otherwise. If both line segments are parallel and colinear, this method returns false.

This method can be overloaded in derived classes and other information to accellerate the computations.

References lti::abs(), lti::condRoundCastTo(), lti::tline< T >::end, lti::tline< T >::start, lti::tpoint< T >::x, and lti::tpoint< T >::y.

template<class T>

tline<T>& lti::tline< T >::getOrthogonal	(	const tline< T > &	other,
		double	offset
	)			[inline]

Compute the orthogonal line to the other line and leave the result here.

Parameters:

	other	the line segment of which the orthogonal line is going to be computed.
	offset	the offset to the point on the line, where the orthogonal shall start. This parameter is scaled by the length of the line.

Returns:

a reference to this line

This method can be overloaded in derived classes and other information to accellerate the computations.

template<class T>

tline<T>& lti::tline< T >::getOrthogonal

(

double

offset

)

Compute the orthogonal line and leave the result here.

Parameters:

offset

the offset to the point on the line, where the orthogonal shall start. This parameter is scaled by the length of the line.

Returns:

a reference to this line

This method can be overloaded in derived classes and other information to accellerate the computations.

template<class T>

const tpoint<T>& lti::tline< T >::getStart

(

)

const [inline]

return a read only reference to the start point

Referenced by lti::draw< rgbPixel >::line().

template<class T>

bool lti::tline< T >::intersect	(	const tline< T > &	other,
		const trectangle< T > &	rect
	)			[inline]

Compute the part of the other line segment which lies within the given rectangle, and leave the result here.

This method assumes, the rectangle is already consistent, i.e. the rect.ul point is in both coordinates smaller than rect.br.

Returns:

true if part of this line lies within the rectangle or its border, false otherwise.

Reimplemented in lti::tfastLine< T >.

template<class T>

bool lti::tline< T >::intersect

(

const trectangle< T > &

rect

)

Compute the part of this line segment which lies within the given rectangle, and leave the result here.

This method assumes, the rectangle is already consistent, i.e. the rect.ul point is in both coordinates smaller than rect.br.

Returns:

true if part of this line lies within the rectangle or its border, false otherwise.

Reimplemented in lti::tfastLine< T >.

template<class T>

bool lti::tline< T >::intersectXPol	(	const tline< T > &	other,
		const trectangle< T > &	rect
	)			[inline]

Compute the part of the infinite extrapolated line containing the other line segment which lies within the given rectangle, and leave the result here.

This method assumes, the rectangle is already consistent, i.e. the rect.ul point is in both coordinates smaller than rect.br.

Returns:

true if part of this line lies within the rectangle or its border, false otherwise.

Reimplemented in lti::tfastLine< T >.

template<class T>

bool lti::tline< T >::intersectXPol

(

const trectangle< T > &

rect

)

Compute the part of the infinite extrapolated line containing this line segment which lies within the given rectangle, and leave the result here.

This method assumes, the rectangle is already consistent, i.e. the rect.ul point is in both coordinates smaller than rect.br.

Returns:

true if part of this line lies within the rectangle or its border, false otherwise.

Reimplemented in lti::tfastLine< T >.

template<class T>

void lti::tline< T >::invert

(

)

[inline]

exchange the start and end points, making the previous end a start point and the previous start the end point.

Reimplemented in lti::tfastLine< T >.

template<class T>

bool lti::tline< T >::isColinear

(

const tline< T > &

other

)

const

Check if this line segment is parallel and colinear to the other given one.

Parameters:

other

the other line segment to which parallelism is going to be checked.

Returns:

true if both line segments are parallel.

template<class T>

bool lti::tline< T >::isParallel

(

const tline< T > &

other

)

const

Check if this line segment is parallel to the other given one.

Parameters:

other

the other line segment to which parallelism is going to be checked.

Returns:

true if both line segments are parallel.

template<class T>

bool lti::tline< T >::operator!=

(

const tline< T > &

other

)

const [inline]

operator !=

template<class T>

template<class U >

tline<T> lti::tline< T >::operator*

(

const U

c

)

const [inline]

create a new line equal this one scaled by the given c factor.

Reimplemented in lti::tfastLine< T >.

References lti::tline< T >::end, and lti::tline< T >::start.

template<class T>

template<class U >

tline<T>& lti::tline< T >::operator*=

(

const U

c

)

[inline]

scale this line by the given c factor.

Reimplemented in lti::tfastLine< T >.

template<class T>

template<class U >

tline<T> lti::tline< T >::operator/

(

const U

c

)

const [inline]

divide both points by the given c factor

Reimplemented in lti::tfastLine< T >.

References lti::tline< T >::end, and lti::tline< T >::start.

template<class T>

template<class U >

tline<T>& lti::tline< T >::operator/=

(

const U

c

)

[inline]

divide both points of tline<T> by a given factor

Reimplemented in lti::tfastLine< T >.

References lti::tline< T >::divide().

template<class T>

tline<T>& lti::tline< T >::operator=

(

const tline< T > &

other

)

[inline]

operator =

Reimplemented in lti::tfastLine< T >.

References lti::tline< T >::copy().

template<class T>

bool lti::tline< T >::operator==

(

const tline< T > &

other

)

const [inline]

operator ==

template<class T>

template<class U >

tline<T>& lti::tline< T >::scale

(

const U

c

)

[inline]

scale this line by the given c factor.

Reimplemented in lti::tfastLine< T >.

References lti::tline< T >::end, and lti::tline< T >::start.

template<class T>

void lti::tline< T >::set	(	const tpoint< T > &	theStart,
		const tpoint< T > &	theEnd
	)			[inline]

general operator to set both points of the line

Reimplemented in lti::tfastLine< T >.

template<class T>

void lti::tline< T >::setEnd

(

const tpoint< T > &

theEnd

)

[inline]

set the end point.

Does not compute the slope.

Reimplemented in lti::tfastLine< T >.

template<class T>

void lti::tline< T >::setStart

(

const tpoint< T > &

theStart

)

[inline]

set the start point.

Reimplemented in lti::tfastLine< T >.

template<class T>

T lti::tline< T >::sqrLength

(

)

const [inline]

square of the length of this line

template<class T>

tline<T>& lti::tline< T >::translate	(	const tline< T > &	other,
		const tpoint< T > &	p
	)			[inline]

add given point to both ends of the other line and leave the result here.

Parameters:

	other	the other line to be tranlated
	p	the translation factor

Returns:

a reference to this line

template<class T>

tline<T>& lti::tline< T >::translate

(

const tpoint< T > &

p

)

[inline]

add given point to both ends of this line and leave the result here.

Parameters:

p

the other line to be added to this one

Returns:

a reference to this line

Reimplemented in lti::tfastLine< T >.

---

Member Data Documentation

template<class T>

tpoint<T> lti::tline< T >::end [protected]

end point

Referenced by lti::tline< T >::castFrom(), lti::tline< T >::divide(), lti::tfastLine< T >::divide(), lti::tline< T >::getIntersectionPoint(), lti::tline< T >::getIntersectionPointXPol(), lti::tline< T >::operator*(), lti::tfastLine< T >::operator*(), lti::tline< T >::operator/(), lti::tfastLine< T >::operator/(), lti::tline< T >::scale(), and lti::tfastLine< T >::scale().

template<class T>

tpoint<T> lti::tline< T >::start [protected]

start point

Referenced by lti::tline< T >::castFrom(), lti::tline< T >::divide(), lti::tfastLine< T >::divide(), lti::tline< T >::getIntersectionPoint(), lti::tline< T >::getIntersectionPointXPol(), lti::tline< T >::operator*(), lti::tfastLine< T >::operator*(), lti::tline< T >::operator/(), lti::tfastLine< T >::operator/(), lti::tline< T >::scale(), and lti::tfastLine< T >::scale().

---

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

• ltiLine.h