QWT API (中文) 7.3.0
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QwtSplineC1类 参考abstract

Base class for spline interpolations with C1 (first order parametric) continuity 更多...

#include <qwt_spline.h>

类 QwtSplineC1 继承关系图:
QwtSplineG1 QwtSplineInterpolating QwtSpline QwtSplineC2 QwtSplineLocal QwtSplineCubic

Public 成员函数

 QwtSplineC1 ()
 Constructor
 
 ~QwtSplineC1 () override
 Destructor
 
virtual QPainterPath painterPath (const QPolygonF &) const override
 Calculate an interpolated painter path
 
virtual QVector< QLineF > bezierControlLines (const QPolygonF &) const override
 Interpolate a curve with Bezier curves
 
virtual QPolygonF equidistantPolygon (const QPolygonF &, double distance, bool withNodes) const override
 Find an interpolated polygon with "equidistant" points
 
virtual QVector< QwtSplinePolynomialpolynomials (const QPolygonF &) const
 Calculate the interpolating polynomials for a non-parametric spline
 
virtual QVector< double > slopes (const QPolygonF &) const =0
 Find the first derivative at the control points
 
virtual double slopeAtBeginning (const QPolygonF &, double slopeNext) const
 Calculate the slope at the beginning of the spline
 
virtual double slopeAtEnd (const QPolygonF &, double slopeBefore) const
 Calculate the slope at the end of the spline
 
- Public 成员函数 继承自 QwtSplineG1
 QwtSplineG1 ()
 Constructor
 
 ~QwtSplineG1 () override
 Destructor
 
- Public 成员函数 继承自 QwtSplineInterpolating
 QwtSplineInterpolating ()
 Constructor
 
 ~QwtSplineInterpolating () override
 Destructor
 
virtual QPolygonF polygon (const QPolygonF &, double tolerance) const override
 Interpolate a curve by a polygon
 
- Public 成员函数 继承自 QwtSpline
 QwtSpline ()
 Constructor
 
virtual ~QwtSpline ()
 Destructor
 
void setParametrization (int type)
 Set parametrization by type
 
void setParametrization (QwtSplineParametrization *)
 Set parametrization object
 
const QwtSplineParametrizationparametrization () const
 Get parametrization
 
void setBoundaryType (BoundaryType)
 Set boundary type
 
BoundaryType boundaryType () const
 Get boundary type
 
void setBoundaryValue (BoundaryPosition, double value)
 Set boundary value
 
double boundaryValue (BoundaryPosition) const
 Get boundary value
 
void setBoundaryCondition (BoundaryPosition, int condition)
 Set boundary condition
 
int boundaryCondition (BoundaryPosition) const
 Get boundary condition
 
void setBoundaryConditions (int condition, double valueBegin=0.0, double valueEnd=0.0)
 Set boundary conditions for both ends
 
virtual uint locality () const
 Get locality (number of points used for calculation)
 

额外继承的成员函数

- Public 类型 继承自 QwtSpline
enum  BoundaryType { ConditionalBoundaries , PeriodicPolygon , ClosedPolygon }
 Boundary type specifying the spline at its endpoints 更多...
 
enum  BoundaryPosition { AtBeginning , AtEnd }
 position of a boundary condition 更多...
 
enum  BoundaryCondition { Clamped1 , Clamped2 , Clamped3 , LinearRunout }
 Boundary condition 更多...
 

详细描述

Base class for spline interpolations with C1 (first order parametric) continuity

All interpolations with C1 continuity are based on rules for finding the first derivative at some control points.

For non-parametric splines those points are the curve points, while for parametric splines the calculation is done twice using a parameter value t.

参见
QwtSplineParametrization

构造及析构函数说明

◆ QwtSplineC1()

QwtSplineC1::QwtSplineC1 ( )

Constructor

The default setting is a non-closing spline with no parametrization (QwtSplineParametrization::ParameterX).

参见
QwtSpline::setParametrization(), QwtSpline::setBoundaryType()

成员函数说明

◆ bezierControlLines()

QVector< QLineF > QwtSplineC1::bezierControlLines ( const QPolygonF &  points) const
overridevirtual

Interpolate a curve with Bezier curves

Interpolates a polygon piecewise with cubic Bezier curves and returns the 2 control points of each curve as QLineF.

参数
[in]pointsControl points
返回
Control points of the interpolating Bezier curves

实现了 QwtSplineInterpolating.

QwtSplineC2, QwtSplineLocal , 以及 QwtSplineCubic 重载.

◆ equidistantPolygon()

QPolygonF QwtSplineC1::equidistantPolygon ( const QPolygonF &  points,
double  distance,
bool  withNodes 
) const
overridevirtual

Find an interpolated polygon with "equidistant" points

The implementation is optimized for non-parametric curves (QwtSplineParametrization::ParameterX) and falls back to QwtSpline::equidistantPolygon() otherwise.

参数
[in]pointsControl nodes of the spline
[in]distanceDistance between 2 points according to the parametrization
[in]withNodesWhen true, also add the control nodes (even if not being equidistant)
返回
Interpolating polygon
参见
QwtSpline::equidistantPolygon()

重载 QwtSplineInterpolating .

QwtSplineC2 重载.

◆ painterPath()

QPainterPath QwtSplineC1::painterPath ( const QPolygonF &  points) const
overridevirtual

Calculate an interpolated painter path

Interpolates a polygon piecewise into cubic Bezier curves and returns them as QPainterPath.

The implementation calculates the slopes at the control points and converts them into painter path elements in an additional loop.

参数
[in]pointsControl points
返回
QPainterPath that can be rendered by QPainter
注解
Derived spline classes might overload painterPath() to avoid the extra loops for converting results into a QPainterPath

重载 QwtSplineInterpolating .

QwtSplineC2, QwtSplineCubic , 以及 QwtSplineLocal 重载.

◆ polynomials()

QVector< QwtSplinePolynomial > QwtSplineC1::polynomials ( const QPolygonF &  points) const
virtual

Calculate the interpolating polynomials for a non-parametric spline

C1 spline interpolations are based on finding values for the first derivatives at the control points. The interpolating polynomials can be calculated from the first derivatives using QwtSplinePolynomial::fromSlopes().

The default implementation is a two-pass calculation. In derived classes it might be overloaded by a one-pass implementation.

参数
[in]pointsControl points
返回
Interpolating polynomials
注解
The x coordinates need to be increasing or decreasing

QwtSplineC2, QwtSplineCubic , 以及 QwtSplineLocal 重载.

◆ slopeAtBeginning()

double QwtSplineC1::slopeAtBeginning ( const QPolygonF &  points,
double  slopeNext 
) const
virtual

Calculate the slope at the beginning of the spline

参数
[in]pointsControl points
[in]slopeNextValue of the first derivative at the second point
返回
Value of the first derivative at the first point
参见
slopeAtEnd(), QwtSpline::boundaryCondition(), QwtSpline::boundaryValue()

◆ slopeAtEnd()

double QwtSplineC1::slopeAtEnd ( const QPolygonF &  points,
double  slopeBefore 
) const
virtual

Calculate the slope at the end of the spline

参数
[in]pointsControl points
[in]slopeBeforeValue of the first derivative at the point before the last one
返回
Value of the first derivative at the last point
参见
slopeAtBeginning(), QwtSpline::boundaryCondition(), QwtSpline::boundaryValue()

◆ slopes()

QVector< double > QwtSplineC1::slopes ( const QPolygonF &  points) const
pure virtual

Find the first derivative at the control points

参数
pointsControl nodes of the spline
返回
Vector with the values of the 2nd derivate at the control points
注解
The x coordinates need to be increasing or decreasing

QwtSplineC2, QwtSplineCubic , 以及 QwtSplineLocal 内被实现.


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