QwtSplineInterpolating(3)

💖 QwtSplineInterpolating(3) 💖

okay bestie, this page is from the Library Functions Manual — it’s the base-class page for a spline interpolation, and it’s giving foundational icon energy. 💅

🌸 NAME 🌸

QwtSplineInterpolating — Base class for a spline interpolation.

✨ SYNOPSIS ✨

#include <qwt_spline.h>

Inherits QwtSpline.

Inherited by QwtSplineG1.

💅 Public Member Functions 💅

• QwtSplineInterpolating () — Constructor.
• virtual ~QwtSplineInterpolating () — Destructor.
• virtual QPolygonF equidistantPolygon (const QPolygonF &, double distance, bool withNodes) const — Find an interpolated polygon with equidistant"points.
• virtual QPolygonF polygon (const QPolygonF &, double tolerance) const — override. Interpolate a curve by a polygon.
• virtual QPainterPath painterPath (const QPolygonF &) const override — Interpolate a curve with Bezier curves.
• virtual QVector< QLineF > bezierControlLines (const QPolygonF &) const — =0. Interpolate a curve with Bezier curves.

🌈 Public Member Functions inherited from QwtSpline 🌈

• QwtSpline () — Constructor.
• virtual ~QwtSpline () — Destructor.
• void setParametrization (int type)
• void setParametrization (QwtSplineParametrization *)
• const QwtSplineParametrization * parametrization () const
• void setBoundaryType (BoundaryType)
• BoundaryType boundaryType () const
• void setBoundaryValue (BoundaryPosition, double value) — Define the boundary value.
• double boundaryValue (BoundaryPosition) const
• void setBoundaryCondition (BoundaryPosition, int condition) — Define the condition for an endpoint of the spline.
• int boundaryCondition (BoundaryPosition) const
• void setBoundaryConditions (int condition, double valueBegin=0.0, double valueEnd=0.0) — Define the condition at the endpoints of a spline.
• virtual uint locality () const

🧬 Additional Inherited Members 🧬

Public Types inherited from QwtSpline

enum BoundaryType { ConditionalBoundaries, PeriodicPolygon, ClosedPolygon }
enum BoundaryPosition { AtBeginning, AtEnd }
enum BoundaryCondition { Clamped1, Clamped2, Clamped3, LinearRunout }

Boundary condition.

🦋 Detailed Description 🦋

Base class for a spline interpolation.

Spline interpolation is the process of interpolating a set of points piecewise with polynomials. The initial set of points is preserved.

Definition at line 193 of file qwt_spline.h.

🛠️ Constructor & Destructor Documentation 🛠️

QwtSplineInterpolating::QwtSplineInterpolating ()

QwtSplineInterpolating::QwtSplineInterpolating ()

Constructor.

Definition at line 711 of file qwt_spline.cpp.

QwtSplineInterpolating::~QwtSplineInterpolating () [virtual]

QwtSplineInterpolating::~QwtSplineInterpolating () [virtual]

Destructor.

Definition at line 716 of file qwt_spline.cpp.

✨ Member Function Documentation ✨

🌀 QwtSplineInterpolating::bezierControlLines

virtual QVector< QLineF > QwtSplineInterpolating::bezierControlLines (const
    QPolygonF & points) const [pure virtual]

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.

Parameters

• points — Control points

Returns

• Control points of the interpolating Bezier curves

Implemented in QwtSplineC1, QwtSplineC2, QwtSplineCubic, QwtSplineLocal, and QwtSplinePleasing.

🫶 QwtSplineInterpolating::equidistantPolygon

QPolygonF QwtSplineInterpolating::equidistantPolygon (const QPolygonF &
    points, double distance, bool withNodes) const [virtual]

Find an interpolated polygon with "equidistant" points. When withNodes is disabled all points of the resulting polygon will be equidistant according to the parametrization.

When withNodes is enabled the resulting polygon will also include the control points and the interpolated points are always aligned to the control point before ( points[i] + i * distance ).

The implementation calculates bezier curves first and calculates the interpolated points in a second run.

Parameters

• points — Control nodes of the spline
• distance — Distance between 2 points according to the parametrization
• withNodes — When true, also add the control nodes ( even if not being equidistant )

Returns

• Interpolating polygon

See also: bezierControlLines()

Reimplemented in QwtSplineC1, and QwtSplineC2.

Definition at line 863 of file qwt_spline.cpp.

🎀 QwtSplineInterpolating::painterPath

QPainterPath QwtSplineInterpolating::painterPath (const QPolygonF & points)
    const [override],  [virtual]

Interpolate a curve with Bezier curves. Interpolates a polygon piecewise with cubic Bezier curves and returns them as QPainterPath.

The implementation calculates the Bezier control lines first and converts them into painter path elements in an additional loop.

Parameters

• points — Control points

Returns

• Painter path, that can be rendered by QPainter

Note: Derived spline classes might overload painterPath() to avoid the extra loops for converting results into a QPainterPath

See also: bezierControlLines()

Implements QwtSpline.

Reimplemented in QwtSplineC1, QwtSplineC2, QwtSplineCubic, QwtSplineLocal, and QwtSplinePleasing.

Definition at line 748 of file qwt_spline.cpp.

🌟 QwtSplineInterpolating::polygon

QPolygonF QwtSplineInterpolating::polygon (const QPolygonF & points, double
    tolerance) const [override],  [virtual]

Interpolate a curve by a polygon. Interpolates a polygon piecewise with Bezier curves approximating them by polygons.

The approximation is based on "Piecewise Linear Approximation of Bézier Curves" by Roger Willcocks ( http://www.rops.org )

Parameters

• points — Control points
• tolerance — Maximum for the accepted error of the approximation

Returns

• polygon approximating the interpolating polynomials

See also: bezierControlLines(), QwtSplineBezier::toPolygon()

Reimplemented from QwtSpline.

Definition at line 805 of file qwt_spline.cpp.

👑 Author 👑

Generated automatically by Doxygen for Qwt User's Guide from the source code.

🎀 and that’s the whole page, bestie. Source/version energy: Qwt User's Guide; page: QwtSplineInterpolating(3). Date? not printed on this page, so no invented date — periodt. 💖