A 1D curve for animating a single value over time. More...

#include <Curve1D.h>

Classes
struct	ControlPoint
	Stores position and tangents to control spline interpolation. More...

Public Member Functions
void	Clear ()
	Removes all control points.

bool	IsEmpty () const
	Checks whether the curve has any control point.

ControlPoint &	AddControlPoint (double fPos)
	Appends a control point. SortControlPoints() must be called to before evaluating the curve.

void	RecomputeExtents ()
	Updates the min/max X value that can be retrieved through GetExtents().

void	QueryExtents (double &ref_fMinx, double &ref_fMaxx) const
	returns the min and max position value across all control points.

void	QueryExtremeValues (double &ref_fMinVal, double &ref_fMaxVal) const
	Returns the min and max Y value across the curve. For this information to be available, the linear approximation of the curve must have been computed, otherwise stale values will be returned.

plUInt32	GetNumControlPoints () const
	Returns the number of control points.

const ControlPoint &	GetControlPoint (plUInt32 uiIdx) const
	Const access to a control point.

ControlPoint &	ModifyControlPoint (plUInt32 uiIdx)
	Non-const access to a control point. If you modify the position, SortControlPoints() has to be called before evaluating the curve.

void	SortControlPoints ()
	Sorts the control point arrays by their position. The CPs have to be sorted before calling Evaluate(), otherwise the result will be wrong.

double	Evaluate (double fPosition) const
	Evaluates the curve at the given position (x coordinate) and returns the value Y value at that point.

double	ConvertNormalizedPos (double fPos) const
	Takes the normalized x coordinate [0;1] and converts it into a valid position on the curve.

double	NormalizeValue (double value) const
	Takes a value (typically returned by Evaluate()) and normalizes it into [0;1] range.

plUInt64	GetHeapMemoryUsage () const
	How much heap memory the curve uses.

void	Save (plStreamWriter &inout_stream) const
	Stores the current state in a stream.

void	Load (plStreamReader &inout_stream)
	Restores the state from a stream.

void	CreateLinearApproximation (double fMaxError=0.01, plUInt8 uiMaxSubDivs=8)
	Pre-computes sample points for linear interpolation that approximate the curve within the allowed error threshold.

const plHybridArray< plVec2d, 24 > &	GetLinearApproximation () const

void	ClampTangents ()
	Adjusts the tangents such that the curve cannot make loopings.

void	ApplyTangentModes ()
	Adjusts the tangents in accordance to the specified tangent modes at each control point.

void	MakeFixedLengthTangentLeft (plUInt32 uiCpIdx)
	Typically called by ApplyTangentModes() for specific control points. Control points must be in sorted order.

void	MakeFixedLengthTangentRight (plUInt32 uiCpIdx)
	Typically called by ApplyTangentModes() for specific control points. Control points must be in sorted order.

void	MakeLinearTangentLeft (plUInt32 uiCpIdx)
	Typically called by ApplyTangentModes() for specific control points. Control points must be in sorted order.

void	MakeLinearTangentRight (plUInt32 uiCpIdx)
	Typically called by ApplyTangentModes() for specific control points. Control points must be in sorted order.

void	MakeAutoTangentLeft (plUInt32 uiCpIdx)

void	MakeAutoTangentRight (plUInt32 uiCpIdx)

Detailed Description

A 1D curve for animating a single value over time.

Member Function Documentation

◆ ApplyTangentModes()

void plCurve1D::ApplyTangentModes ( )

Adjusts the tangents in accordance to the specified tangent modes at each control point.

Note: All control points must already be in sorted order, so call SortControlPoints() first if necessary.

◆ ConvertNormalizedPos()

double plCurve1D::ConvertNormalizedPos ( double fPos ) const

Takes the normalized x coordinate [0;1] and converts it into a valid position on the curve.

Note: This only works when the curve extents are available. See QueryExtents() and RecomputeExtents().

See also: RecomputeExtents; QueryExtents

◆ CreateLinearApproximation()

void plCurve1D::CreateLinearApproximation	(	double	fMaxError = 0.01,
		plUInt8	uiMaxSubDivs = 8 )

Pre-computes sample points for linear interpolation that approximate the curve within the allowed error threshold.

Note: All control points must already be in sorted order, so call SortControlPoints() first if necessary.

Todo: Since we do this, we actually don't need the linear approximation anymore and could just evaluate the full curve

◆ Evaluate()

double plCurve1D::Evaluate ( double fPosition ) const

Evaluates the curve at the given position (x coordinate) and returns the value Y value at that point.

This uses the linear approximation of the curve, so CreateLinearApproximation() must have been called first.

See also: CreateLinearApproximation

◆ NormalizeValue()

double plCurve1D::NormalizeValue ( double value ) const

Takes a value (typically returned by Evaluate()) and normalizes it into [0;1] range.

Note: This only works when the linear approximation of the curve has been computed first.

◆ QueryExtents()

void plCurve1D::QueryExtents	(	double &	ref_fMinx,
		double &	ref_fMaxx ) const

returns the min and max position value across all control points.

The returned values are only up to date if either SortControlPoints() or RecomputeExtents() was called before. Otherwise they will contain stale values.

◆ RecomputeExtents()

void plCurve1D::RecomputeExtents ( )

Updates the min/max X value that can be retrieved through GetExtents().

This is automatically done when SortControlPoints() is called. It can be called manually, if the information is required without sorting.

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

Code/Engine/Foundation/Tracks/Curve1D.h
Code/Engine/Foundation/Tracks/Implementation/Curve1D.cpp

Classes

Public Member Functions