Line2 Class Reference

Lines in the plane. More...

#include <segment.h>

Inheritance diagram for Line2:

Public Member Functions
	Line2 ()
	Empty.
	Line2 (const Vector2 &, const Vector2 &)
	Creates a line in the plane. More...
	Line2 (const Segment2 &)
	Creates a line from a segment. More...
Vector2	Vertex (int) const
	Return one of the vertices of the line.
Vector2 &	Vertex (int)
	Return one of the vertices of the line.
bool	Intersection (const Line2 &, Vector2 &) const
	Compute the intersection between two lines. More...
bool	Intersection (const Segment2 &, Vector2 &) const
	Compute the intersection between a line and a segment. More...
Vector2	Symmetry (const Vector2 &) const
	Compute the point symmetric to the line. More...
Box2	Symmetry (const Box2 &) const
	Compute the box bounding the box symmetric to the line. More...
Circle2	Symmetry (const Circle2 &) const
	Compute the circle symmetric to the line. More...
double	R (const Vector2 &) const
	Compute the squared distance to the line. More...
bool	IsLeftOrOn (const Vector2 &, const double &=0.0) const
	Compute the position of a point with respect to a line. More...
bool	IsRightOrOn (const Vector2 &, const double &=0.0) const
	Compute the position of a point with respect to a line. More...
Public Member Functions inherited from Segment2
	Segment2 ()
	Empty.
	Segment2 (const Vector2 &, const Vector2 &)
	Creates a planar segment given end vertices. More...
	Segment2 (const Segment &)
	Creates a planar segment given a three dimensional segment. More...
	~Segment2 ()
	Empty.
Vector2	Vertex (int) const
	Return one of the end vertex of the axis.
Vector2 &	Vertex (int)
	Return one of the end vertex of the axis.
Vector2	VertexAt (const double &) const
	Compute a point on the segment. More...
Vector2	Center () const
	Compute the center of the segment.
Vector2	GetAxis () const
	Returns the normalized axis vector.
Box2	GetBox () const
	Compute the bounding box of the segment.
Vector2	Orthogonal () const
	Compute an orthogonal vector to the segment. More...
void	Translate (const Vector2 &)
	Translates a segment. More...
void	Rotate (const Matrix2 &)
	Translates a segment. More...
void	Scale (const double &)
	Uniformly scales a segment. More...
double	Length () const
	Return axis length.
void	Draw (QGraphicsScene &, const QPen &=QPen()) const
	Draw a segment. More...
void	DrawArrow (QGraphicsScene &, const double &, const QPen &=QPen(), const QBrush &=QBrush()) const
	Draw a segment as an arrow. More...
double	R (const Vector2 &) const
	Compute the squared distance to the segment. More...
double	R (const Vector2 &, double &) const
	Compute the squared distance to the axis edge characterized by its end points. More...
Vector2	Normal (const Vector2 &) const
	Compute the normal vector between a point and its projection onto the segment. More...
bool	Intersect (const Segment2 &) const
	Test if two segments intersect. More...
bool	IntersectOpen (const Segment2 &) const
	This functions tests if two segments intersect. More...
bool	Intersection (const Segment2 &, Vector2 &) const
	Compute the intersection between two segments. More...

Static Public Attributes
static const Line2	X
	Horizontal.
static const Line2	Y
	Vertical.
Static Public Attributes inherited from Segment2
static constexpr const double	epsilon = 1e-8
	Epsilon value for intersection test.

Additional Inherited Members
Static Public Member Functions inherited from Segment2
static Vector2	Intersect (const Vector2 &, const Vector2 &, const double, const double, const double=0.0)
	Compute the intersection between the line f(x)=y and a line such that f(a)=va and f(b)=vb, on the segment ab. More...
Protected Attributes inherited from Segment2
Vector2	b = Vector2::X
	End vertices of the segment.

Detailed Description

Lines in the plane.

See also

Segment2

Constructor & Destructor Documentation

Line2() [1/2]

Line2::Line2 ( const Vector2 &  a, const Vector2 &  b  )

inlineexplicit

Creates a line in the plane.

Parameters

a,b	Two points.

Line2() [2/2]

Line2::Line2 ( const Segment2 &  s )

inlineexplicit

Creates a line from a segment.

Parameters

s

Segment.

Member Function Documentation

Intersection() [1/2]

bool Line2::Intersection	(	const Line2 &	l,
		Vector2 &	p
	)		const

Compute the intersection between two lines.

Note that the algorithm is the same as for segments, except that the range of the intersection parameters is not checked.

Parameters

l	Other line.
p	Intersection point.

Intersection() [2/2]

bool Line2::Intersection	(	const Segment2 &	e,
		Vector2 &	p
	)		const

Compute the intersection between a line and a segment.

Note that the algorithm is the same as for segments, except that the range of the intersection parameters is checked only for the segment.

Parameters

e	Segment.
p	Intersection point.

IsLeftOrOn()

bool Line2::IsLeftOrOn	(	const Vector2 &	p,
		const double &	epsilon = 0.0
	)		const

Compute the position of a point with respect to a line.

Parameters

p	Point
epsilon	Precision.

IsRightOrOn()

bool Line2::IsRightOrOn	(	const Vector2 &	p,
		const double &	epsilon = 0.0
	)		const

Compute the position of a point with respect to a line.

Parameters

p	Point
epsilon	Precision.

R()

double Line2::R

(

const Vector2 &

p

)

const

Compute the squared distance to the line.

Parameters

p

Point.

Symmetry() [1/3]

Box2 Line2::Symmetry

(

const Box2 &

box

)

const

Compute the box bounding the box symmetric to the line.

Parameters

box

The box.

Symmetry() [2/3]

Circle2 Line2::Symmetry

(

const Circle2 &

c

)

const

Compute the circle symmetric to the line.

Parameters

c

Circle.

Symmetry() [3/3]

Vector2 Line2::Symmetry

(

const Vector2 &

p

)

const

Compute the point symmetric to the line.

Parameters

p

Point.