QuadricCurve2Set Class Reference

Piecewise quadric curves. More...

#include <curveset.h>

Public Member Functions
	QuadricCurve2Set ()
	Creates an empty piecewise quadric curve.
	QuadricCurve2Set (const QVector< Vector2 > &)
	Creates the piecewise quadric curve given a set of control points. More...
	QuadricCurve2Set (const QVector< QuadricCurve2 > &)
	Create a set of quadric curves. More...
	QuadricCurve2Set (const QuadricCurveSet &)
	Creates a piecewise cubic curve in the plane from a similar curve. More...
	~QuadricCurve2Set ()
	Destroys a piecewise quadric curve.
int	Size () const
	Returns the number of elements of the piecewise quadric curve.
QuadricCurve2	operator() (int) const
	Read only access to the elements of the piecewise quadric curve.
void	Translate (const Vector2 &)
	Translate the curve. More...
Box2	GetBox () const
	Compute the bounding box of the curve.
double	GetLength () const
	Return the length of the curve.
double	GetLength (int) const
	Return the length of the sub-curve. More...
double	Sinuosity () const
	Compute the sinuosity. More...
QVector< Vector2 >	GetDiscretisation (const double &) const
	Generates a discretization of the curve with a linear curvilign absisca parameterization. More...
int	U (const double &, double &) const
	Compute the parameter of the curve corresponding to the input length. More...
double	R (const Vector2 &, double &, int &) const
	This function returns the squared distance between a point and a set of quadric curves. More...
double	UV (const Vector2 &, double &, double &, int &) const
	Compute the inverse mapping for a given input point. More...
bool	Inside (const Vector2 &) const
	Check if a point lies inside the piecewise quadric curve closed contour. More...
bool	Intersect (const Ray2 &, double &) const
	Compute the first intersection between a ray and the curve. More...
int	Intersections (const Ray2 &) const
	Compute the number of intersections between a ray and a piecewize quadric curve. More...
QuadricCurve2Set &	operator+= (const QuadricCurve2Set &)
	Appends a piecewise cubic curve to an existing piecewise cubic curve. More...
void	Draw (QGraphicsScene &, const QPen &=QPen(), const QBrush &=QBrush()) const
	Draw the curve. More...

Protected Attributes
QVector< QuadricCurve2 >	curve
	Set of quadric curves.
QVector< double >	lengths
	Length of every curve (internal optimization)
double	length = 0.0
	Total length (internal optimization)

Detailed Description

Piecewise quadric curves.

This class stores an array of quadric curves.

Constructor & Destructor Documentation

QuadricCurve2Set() [1/3]

QuadricCurve2Set::QuadricCurve2Set ( const QVector< Vector2 > &  p )

explicit

Creates the piecewise quadric curve given a set of control points.

Parameters

p	Control vertices.

QuadricCurve2Set() [2/3]

QuadricCurve2Set::QuadricCurve2Set ( const QVector< QuadricCurve2 > &  s )

explicit

Create a set of quadric curves.

Parameters

s	Set of quadric curves.

QuadricCurve2Set() [3/3]

QuadricCurve2Set::QuadricCurve2Set ( const QuadricCurveSet &  c )

explicit

Creates a piecewise cubic curve in the plane from a similar curve.

Parameters

c

Curve.

Member Function Documentation

Draw()

void QuadricCurve2Set::Draw	(	QGraphicsScene &	scene,
		const QPen &	pen = QPen(),
		const QBrush &	brush = QBrush()
	)		const

Draw the curve.

The brush is not used.

Parameters

scene	Graphics scene.
pen	The pen.
brush	The brush.

GetDiscretisation()

QVector< Vector2 > QuadricCurve2Set::GetDiscretisation

(

const double &

step

)

const

Generates a discretization of the curve with a linear curvilign absisca parameterization.

Parameters

step

Step.

GetLength()

double QuadricCurve2Set::GetLength ( int  k ) const

inline

Return the length of the sub-curve.

Parameters

k	Curve index.

Inside()

bool QuadricCurve2Set::Inside

(

const Vector2 &

p

)

const

Check if a point lies inside the piecewise quadric curve closed contour.

The curve should be closed.

See also

Intersections

Parameters

p

Point.

Intersect()

bool QuadricCurve2Set::Intersect	(	const Ray2 &	ray,
		double &	t
	)		const

Compute the first intersection between a ray and the curve.

Parameters

ray	The ray.
t	Returned intersection depth.

Intersections()

int QuadricCurve2Set::Intersections

(

const Ray2 &

ray

)

const

Compute the number of intersections between a ray and a piecewize quadric curve.

Parameters

ray

The ray.

operator+=()

QuadricCurve2Set & QuadricCurve2Set::operator+=

(

const QuadricCurve2Set &

c

)

Appends a piecewise cubic curve to an existing piecewise cubic curve.

Parameters

c	Argument piecewise cubic curve.

R()

double QuadricCurve2Set::R	(	const Vector2 &	p,
		double &	u,
		int &	k
	)		const

This function returns the squared distance between a point and a set of quadric curves.

See also

QuadicCurve::R()

Parameters

p	Point.
u	Parameter defining the coordinate of the projection of the argument vertex onto the curve.
k	Index of the curve for which the minimum distance was found.

Sinuosity()

double QuadricCurve2Set::Sinuosity

(

)

const

Compute the sinuosity.

Sinusoity is defined as the ratio between the length of the curve and the distance between end points.

Translate()

void QuadricCurve2Set::Translate

(

const Vector2 &

t

)

Translate the curve.

Parameters

t	Translation vector.

U()

int QuadricCurve2Set::U	(	const double &	s,
		double &	u
	)		const

Compute the parameter of the curve corresponding to the input length.

Parameters

s	Input length.
u	Parameter of the i-th curve.

Returns

Identifier of the curve in the piecewise definition.

UV()

double QuadricCurve2Set::UV	(	const Vector2 &	p,
		double &	u,
		double &	v,
		int &	k
	)		const

Compute the inverse mapping for a given input point.

Parameters

p	Point.
u,v	Inverse Coordinates, u will denote the position along the curve and v the signed distance to the curve.
k	Index defining the sub-curve element.