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ignition::math::Spline Class Reference

Splines. More...

#include <ignition/math/Spline.hh>

Public Member Functions

 Spline ()
 constructor More...
 
 ~Spline ()
 destructor More...
 
void AddPoint (const Vector3d &_pt)
 Adds a control point to the end of the spline. More...
 
void AutoCalculate (bool _autoCalc)
 Tells the spline whether it should automatically calculate tangents on demand as points are added. More...
 
void Clear ()
 Clears all the points in the spline. More...
 
Vector3d Interpolate (double _t) const
 Returns an interpolated point based on a parametric value over the whole series. More...
 
Vector3d Interpolate (unsigned int _fromIndex, double _t) const
 Interpolates a single segment of the spline given a parametric value. More...
 
Vector3d Point (unsigned int _index) const
 Gets the detail of one of the control points of the spline. More...
 
unsigned int PointCount () const
 Gets the number of control points in the spline. More...
 
void RecalcTangents ()
 Recalculates the tangents associated with this spline. More...
 
Vector3d Tangent (unsigned int _index) const
 Get the tangent value for a point. More...
 
void Tension (double _t)
 Set the tension parameter. More...
 
double Tension () const
 Get the tension value. More...
 
void UpdatePoint (unsigned int _index, const Vector3d &_value)
 Updates a single point in the spline. More...
 

Protected Attributes

bool autoCalc
 when true, the tangents are recalculated when the control point change More...
 
Matrix4d coeffs
 Matrix of coefficients. More...
 
std::vector< Vector3dpoints
 control points More...
 
std::vector< Vector3dtangents
 tangents More...
 
double tension
 Tension of 0 = Catmull-Rom spline, otherwise a Cardinal spline. More...
 

Detailed Description

Splines.

Constructor & Destructor Documentation

ignition::math::Spline::Spline ( )

constructor

ignition::math::Spline::~Spline ( )

destructor

Member Function Documentation

void ignition::math::Spline::AddPoint ( const Vector3d _pt)

Adds a control point to the end of the spline.

Parameters
[in]_ptpoint to add
void ignition::math::Spline::AutoCalculate ( bool  _autoCalc)

Tells the spline whether it should automatically calculate tangents on demand as points are added.

Remarks
The spline calculates tangents at each point automatically based on the input points. Normally it does this every time a point changes. However, if you have a lot of points to add in one go, you probably don't want to incur this overhead and would prefer to defer the calculation until you are finished setting all the points. You can do this by calling this method with a parameter of 'false'. Just remember to manually call the recalcTangents method when you are done.
Parameters
[in]_autoCalcIf true, tangents are calculated for you whenever a point changes. If false, you must call reclacTangents to recalculate them when it best suits.
void ignition::math::Spline::Clear ( )

Clears all the points in the spline.

Vector3d ignition::math::Spline::Interpolate ( double  _t) const

Returns an interpolated point based on a parametric value over the whole series.

Parameters
[in]_tparameter (range 0 to 1)
Vector3d ignition::math::Spline::Interpolate ( unsigned int  _fromIndex,
double  _t 
) const

Interpolates a single segment of the spline given a parametric value.

Parameters
[in]_fromIndexThe point index to treat as t = 0. fromIndex + 1 is deemed to be t = 1
[in]_tParametric value
Exceptions
IndexExceptionif _fromIndex >= PointCount()
Vector3d ignition::math::Spline::Point ( unsigned int  _index) const

Gets the detail of one of the control points of the spline.

Parameters
[in]_indexthe control point index
Returns
the control point, or [0,0,0] and a message on the error stream
Exceptions
IndexExceptionif _index >= PointCount()
unsigned int ignition::math::Spline::PointCount ( ) const

Gets the number of control points in the spline.

Returns
the count
void ignition::math::Spline::RecalcTangents ( )

Recalculates the tangents associated with this spline.

Remarks
If you tell the spline not to update on demand by calling setAutoCalculate(false) then you must call this after completing your updates to the spline points.
Vector3d ignition::math::Spline::Tangent ( unsigned int  _index) const

Get the tangent value for a point.

Parameters
[in]_indexthe control point index
Exceptions
IndexExceptionif _index >= PointCount()
void ignition::math::Spline::Tension ( double  _t)

Set the tension parameter.

A value of 0 = Catmull-Rom spline.

Parameters
[in]_tTension value between 0.0 and 1.0
double ignition::math::Spline::Tension ( ) const

Get the tension value.

Returns
The value of the tension, which is between 0.0 and 1.0
void ignition::math::Spline::UpdatePoint ( unsigned int  _index,
const Vector3d _value 
)

Updates a single point in the spline.

Remarks
an error to the error stream is printed when the index is out of bounds
Parameters
[in]_indexthe control point index
[in]_valuethe new position
Exceptions
IndexExceptionif _index >= PointCount()

Member Data Documentation

bool ignition::math::Spline::autoCalc
protected

when true, the tangents are recalculated when the control point change

Matrix4d ignition::math::Spline::coeffs
protected

Matrix of coefficients.

std::vector<Vector3d> ignition::math::Spline::points
protected

control points

std::vector<Vector3d> ignition::math::Spline::tangents
protected

tangents

double ignition::math::Spline::tension
protected

Tension of 0 = Catmull-Rom spline, otherwise a Cardinal spline.


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