qwt_spline.h

/******************************************************************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *
 * Modified by ChenZongYan in 2024 <czy.t@163.com>
 *   Summary of major modifications (see ChangeLog.md for full history):
 *   1. CMake build system & C++11 throughout.
 *   2. Core panner/ zoomer refactored:
 *        - QwtPanner → QwtCachePanner (pixmap-cache version)
 *        - New real-time QwtPlotPanner derived from QwtPicker.
 *   3. Zoomer supports multi-axis.
 *   4. Parasite-plot framework:
 *        - QwtFigure, QwtPlotParasiteLayout, QwtPlotTransparentCanvas,
 *        - QwtPlotScaleEventDispatcher, built-in pan/zoom on axis.
 *   5. New picker: QwtPlotSeriesDataPicker (works with date axis).
 *   6. Raster & color-map extensions:
 *        - QwtGridRasterData (2-D table + interpolation)
 *        - QwtLinearColorMap::stopColors(), stopPos() API rename.
 *   7. Bar-chart: expose pen/brush control.
 *   8. Amalgamated build: single QwtPlot.h / QwtPlot.cpp pair in src-amalgamate.
 *****************************************************************************/
 
#ifndef QWT_SPLINE_H
#define QWT_SPLINE_H
 
#include "qwt_global.h"
#include "qwt_spline.h"
 
class QwtSplineParametrization;
class QwtSplinePolynomial;
class QPainterPath;
class QLineF;
class QPolygonF;
 
#if QT_VERSION < 0x060000
template< typename T > class QVector;
#endif
 
class QWT_EXPORT QwtSpline
{
  public:
    enum BoundaryType
    {
        ConditionalBoundaries,
 
        PeriodicPolygon,
 
        ClosedPolygon
    };
 
    enum BoundaryPosition
    {
        AtBeginning,
 
        AtEnd
    };
 
    enum BoundaryCondition
    {
        Clamped1,
 
        Clamped2,
 
        Clamped3,
 
        LinearRunout
    };
 
    QwtSpline();
    virtual ~QwtSpline();
 
    void setParametrization( int type );
    void setParametrization( QwtSplineParametrization* );
    const QwtSplineParametrization* parametrization() const;
 
    void setBoundaryType( BoundaryType );
    BoundaryType boundaryType() const;
 
    void setBoundaryValue( BoundaryPosition, double value );
    double boundaryValue( BoundaryPosition ) const;
 
    void setBoundaryCondition( BoundaryPosition, int condition );
    int boundaryCondition( BoundaryPosition ) const;
 
    void setBoundaryConditions( int condition,
        double valueBegin = 0.0, double valueEnd = 0.0 );
 
    virtual QPolygonF polygon( const QPolygonF&, double tolerance ) const;
    virtual QPainterPath painterPath( const QPolygonF& ) const = 0;
 
    virtual uint locality() const;
 
  private:
    Q_DISABLE_COPY(QwtSpline)
 
    class PrivateData;
    PrivateData* m_data;
};
 
class QWT_EXPORT QwtSplineInterpolating : public QwtSpline
{
  public:
    QwtSplineInterpolating();
    virtual ~QwtSplineInterpolating();
 
    virtual QPolygonF equidistantPolygon( const QPolygonF&,
        double distance, bool withNodes ) const;
 
    virtual QPolygonF polygon(
        const QPolygonF&, double tolerance ) const override;
 
    virtual QPainterPath painterPath( const QPolygonF& ) const override;
    virtual QVector< QLineF > bezierControlLines( const QPolygonF& ) const = 0;
 
  private:
    Q_DISABLE_COPY(QwtSplineInterpolating)
};
 
class QWT_EXPORT QwtSplineG1 : public QwtSplineInterpolating
{
  public:
    QwtSplineG1();
    virtual ~QwtSplineG1();
};
 
class QWT_EXPORT QwtSplineC1 : public QwtSplineG1
{
  public:
    QwtSplineC1();
    virtual ~QwtSplineC1();
 
    virtual QPainterPath painterPath( const QPolygonF& ) const override;
    virtual QVector< QLineF > bezierControlLines( const QPolygonF& ) const override;
 
    virtual QPolygonF equidistantPolygon( const QPolygonF&,
        double distance, bool withNodes ) const override;
 
    // these methods are the non parametric part
    virtual QVector< QwtSplinePolynomial > polynomials( const QPolygonF& ) const;
    virtual QVector< double > slopes( const QPolygonF& ) const = 0;
 
    virtual double slopeAtBeginning( const QPolygonF&, double slopeNext ) const;
    virtual double slopeAtEnd( const QPolygonF&, double slopeBefore ) const;
};
 
class QWT_EXPORT QwtSplineC2 : public QwtSplineC1
{
  public:
    enum BoundaryConditionC2
    {
        CubicRunout = LinearRunout + 1,
 
        NotAKnot
    };
 
    QwtSplineC2();
    virtual ~QwtSplineC2();
 
    virtual QPainterPath painterPath( const QPolygonF& ) const override;
    virtual QVector< QLineF > bezierControlLines( const QPolygonF& ) const override;
 
    virtual QPolygonF equidistantPolygon( const QPolygonF&,
        double distance, bool withNodes ) const override;
 
    // calculating the parametric equations
    virtual QVector< QwtSplinePolynomial > polynomials( const QPolygonF& ) const override;
    virtual QVector< double > slopes( const QPolygonF& ) const override;
    virtual QVector< double > curvatures( const QPolygonF& ) const = 0;
};
 
#endif