A two dimensional line segment. More...

#include <ignition/math/Line2.hh>

Public Member Functions
	Line2 (const math::Vector2< T > &_ptA, const math::Vector2< T > &_ptB)
	Constructor. More...

	Line2 (double _x1, double _y1, double _x2, double _y2)
	Constructor. More...

bool	Collinear (const math::Vector2< T > &_pt, double _epsilon=1e-6) const
	Check if the given point is collinear with this line. More...

bool	Collinear (const math::Line2< T > &_line, double _epsilon=1e-6) const
	Check if the given line is collinear with this line. More...

double	CrossProduct (const Line2< T > &_line) const
	Return the cross product of this line and the given line. More...

double	CrossProduct (const Vector2< T > &_pt) const
	Return the cross product of this line and the given point. More...

bool	Intersect (const Line2< T > &_line, double _epsilon=1e-6) const
	Check if this line intersects the given line segment. More...

bool	Intersect (const Line2< T > &_line, math::Vector2< T > &_pt, double _epsilon=1e-6) const
	Check if this line intersects the given line segment. More...

T	Length () const
	Get the length of the line. More...

bool	OnSegment (const math::Vector2< T > &_pt, double _epsilon=1e-6) const
	Return whether the given point is on this line segment. More...

bool	operator!= (const Line2< T > &_line) const
	Inequality operator. More...

bool	operator== (const Line2< T > &_line) const
	Equality operator. More...

math::Vector2< T >	operator[] (size_t _index) const
	Get the start or end point. More...

bool	Parallel (const math::Line2< T > &_line, double _epsilon=1e-6) const
	Check if the given line is parallel with this line. More...

void	Set (const math::Vector2< T > &_ptA, const math::Vector2< T > &_ptB)
	Set the start and end point of the line segment. More...

void	Set (double _x1, double _y1, double _x2, double _y2)
	Set the start and end point of the line segment. More...

double	Slope () const
	Get the slope of the line. More...

bool	Within (const math::Vector2< T > &_pt, double _epsilon=1e-6) const
	Check if the given point is between the start and end points of the line segment. More...

Friends
std::ostream &	operator<< (std::ostream &_out, const Line2< T > &_line)
	Stream extraction operator. More...

Detailed Description

template<typename T>
class ignition::math::Line2< T >

A two dimensional line segment.

The line is defined by a start and end point.

Constructor & Destructor Documentation

template<typename T>

ignition::math::Line2< T >::Line2	(	const math::Vector2< T > &	_ptA,
		const math::Vector2< T > &	_ptB
	)

inline

Constructor.

Parameters

[in]	_ptA	Start point of the line segment
[in]	_ptB	End point of the line segment

References ignition::math::Line2< T >::Set().

template<typename T>

ignition::math::Line2< T >::Line2	(	double	_x1,
		double	_y1,
		double	_x2,
		double	_y2
	)

inline

Constructor.

Parameters

[in]	_x1	X coordinate of the start point.
[in]	_y1	Y coordinate of the start point.
[in]	_x2	X coordinate of the end point.
[in]	_y2	Y coordinate of the end point.

References ignition::math::Line2< T >::Set().

Member Function Documentation

template<typename T>

bool ignition::math::Line2< T >::Collinear	(	const math::Vector2< T > &	_pt,
		double	_epsilon = `1e-6`
	)		const

inline

Check if the given point is collinear with this line.

Parameters

[in]	_pt	The point to check.
[in]	_epsilon	The error bounds within which the collinear check will return true.

Returns: Return true if the point is collinear with this line, false otherwise.

References ignition::math::Line2< T >::CrossProduct(), and ignition::math::equal().

Referenced by ignition::math::Line2< T >::OnSegment().

template<typename T>

bool ignition::math::Line2< T >::Collinear	(	const math::Line2< T > &	_line,
		double	_epsilon = `1e-6`
	)		const

inline

Check if the given line is collinear with this line.

This is the AND of Parallel and Intersect.

Parameters

[in]	_line	The line to check.
[in]	_epsilon	The error bounds within which the collinear check will return true.

Returns: Return true if the line is collinear with this line, false otherwise.

References ignition::math::Line2< T >::Intersect(), and ignition::math::Line2< T >::Parallel().

template<typename T>

double ignition::math::Line2< T >::CrossProduct ( const Line2< T > & _line ) const

inline

Return the cross product of this line and the given line.

Give 'a' as this line and 'b' as given line, the equation is: (a.start.x - a.end.x) * (b.start.y - b.end.y) - (a.start.y - a.end.y) * (b.start.x - b.end.x)

Parameters

[in] _line Line for the cross product computation.

Returns: Return the cross product of this line and the given line.

Referenced by ignition::math::Line2< T >::Collinear(), ignition::math::Line2< T >::Intersect(), and ignition::math::Line2< T >::Parallel().

template<typename T>

double ignition::math::Line2< T >::CrossProduct ( const Vector2< T > & _pt ) const

inline

Return the cross product of this line and the given point.

Given 'a' and 'b' as the start and end points, the equation is:

Parameters

[in] _pt Point for the cross product computation.

Returns: Return the cross product of this line and the given point.

References ignition::math::Vector2< T >::X(), and ignition::math::Vector2< T >::Y().

template<typename T>

bool ignition::math::Line2< T >::Intersect	(	const Line2< T > &	_line,
		double	_epsilon = `1e-6`
	)		const

inline

Check if this line intersects the given line segment.

Parameters

[in]	_line	The line to check for intersection.
[in]	_epsilon	The error bounds within which the intersection check will return true.

Returns: True if an intersection was found.

Referenced by ignition::math::Line2< T >::Collinear(), and ignition::math::Triangle< T >::Intersects().

template<typename T>

bool ignition::math::Line2< T >::Intersect	(	const Line2< T > &	_line,
		math::Vector2< T > &	_pt,
		double	_epsilon = `1e-6`
	)		const

inline

Check if this line intersects the given line segment.

The point of intersection is returned in the _result parameter.

Parameters

[in]	_line	The line to check for intersection.
[out]	_pt	The point of intersection. This value is only valid if the return value is true.
[in]	_epsilon	The error bounds within which the intersection check will return true.

Returns: True if an intersection was found.

References ignition::math::Line2< T >::CrossProduct(), ignition::math::equal(), ignition::math::max(), ignition::math::min(), ignition::math::Line2< T >::Within(), ignition::math::Vector2< T >::X(), and ignition::math::Vector2< T >::Y().

template<typename T>

T ignition::math::Line2< T >::Length ( ) const

inline

Get the length of the line.

Returns: The length of the line.

template<typename T>

bool ignition::math::Line2< T >::OnSegment	(	const math::Vector2< T > &	_pt,
		double	_epsilon = `1e-6`
	)		const

inline

Return whether the given point is on this line segment.

Parameters

[in]	_pt	Point to check.
[in]	_epsilon	The error bounds within which the OnSegment check will return true.

Returns: True if the point is on the segement.

References ignition::math::Line2< T >::Collinear(), and ignition::math::Line2< T >::Within().

template<typename T>

bool ignition::math::Line2< T >::operator!= ( const Line2< T > & _line ) const

inline

Inequality operator.

Parameters

[in] _line Line to compare for inequality.

Returns: True if the given line is not to this line

template<typename T>

bool ignition::math::Line2< T >::operator== ( const Line2< T > & _line ) const

inline

Equality operator.

Parameters

[in] _line Line to compare for equality.

Returns: True if the given line is equal to this line

template<typename T>

math::Vector2<T> ignition::math::Line2< T >::operator[] ( size_t _index ) const

inline

Get the start or end point.

Parameters

[in] _index 0 = start point, 1 = end point.

Exceptions

IndexException if _index is > 1.

template<typename T>

bool ignition::math::Line2< T >::Parallel	(	const math::Line2< T > &	_line,
		double	_epsilon = `1e-6`
	)		const

inline

Check if the given line is parallel with this line.

Parameters

[in]	_line	The line to check.
[in]	_epsilon	The error bounds within which the parallel check will return true.

Returns: Return true if the line is parallel with this line, false otherwise. Return true if either line is a point (line with zero length).

References ignition::math::Line2< T >::CrossProduct(), and ignition::math::equal().

Referenced by ignition::math::Line2< T >::Collinear().

template<typename T>

void ignition::math::Line2< T >::Set	(	const math::Vector2< T > &	_ptA,
		const math::Vector2< T > &	_ptB
	)

inline

Set the start and end point of the line segment.

Parameters

[in]	_ptA	Start point of the line segment
[in]	_ptB	End point of the line segment

Referenced by ignition::math::Line2< T >::Line2().

template<typename T>

void ignition::math::Line2< T >::Set	(	double	_x1,
		double	_y1,
		double	_x2,
		double	_y2
	)

inline

Set the start and end point of the line segment.

Parameters

[in]	_x1	X coordinate of the start point.
[in]	_y1	Y coordinate of the start point.
[in]	_x2	X coordinate of the end point.
[in]	_y2	Y coordinate of the end point.

template<typename T>

double ignition::math::Line2< T >::Slope ( ) const

inline

Get the slope of the line.

Returns: The slope of the line, NAN_D if the line is vertical.

References ignition::math::equal(), and ignition::math::NAN_D.

template<typename T>

bool ignition::math::Line2< T >::Within	(	const math::Vector2< T > &	_pt,
		double	_epsilon = `1e-6`
	)		const

inline

Check if the given point is between the start and end points of the line segment.

This does not imply that the point is on the segment.

Parameters

[in]	_pt	Point to check.
[in]	_epsilon	The error bounds within which the within check will return true.

Returns: True if the point is on the segement.

References ignition::math::max(), ignition::math::min(), ignition::math::Vector2< T >::X(), and ignition::math::Vector2< T >::Y().

Referenced by ignition::math::Line2< T >::Intersect(), and ignition::math::Line2< T >::OnSegment().

Friends And Related Function Documentation

template<typename T>

std::ostream& operator<<	(	std::ostream &	_out,
		const Line2< T > &	_line
	)

friend

Stream extraction operator.

Parameters

[in]	_out	output stream
[in]	_pt	Line2 to output

Returns: The stream

Exceptions

N/A.

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

Line2.hh

Public Member Functions

Friends

Detailed Description

template<typename T> class ignition::math::Line2< T >

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

template<typename T>
class ignition::math::Line2< T >