Package net.paulhertz.pixelaudio.curves

Class PAKeyframeControlCurve

java.lang.Object

net.paulhertz.pixelaudio.curves.PAKeyframeControlCurve

All Implemented Interfaces:

PAControlCurve

public final class PAKeyframeControlCurve
extends Object
implements PAControlCurve

Models piecewise-linear scalar control curve defined by keyframes. u ∈ [0,1] -> value where: - times01 is a strictly ascending list of control times in [0,1] - values is a list of corresponding scalar values Typical uses: - gesture dynamics / gain shaping - pan curves - pitch modulation - other normalized control data This class makes no strong assumptions about the range of values. For dynamics, values will usually be in [0,1], but other ranges are allowed.

See Also:

• Bagatelle example code

Field Summary

Fields

Modifier and Type	Field	Description
private final int	count
private final float[]	times01
private final float[]	values

Constructor Summary

Constructors

Constructor	Description
PAKeyframeControlCurve(float[] times01, float[] values)

Method Summary

Modifier and Type	Method	Description
private static float	clamp01(float u)
static float[]	expandToSchedule(PAControlCurve curve, GestureSchedule sched)
private int	findSegment(float u)	Find the largest i such that times01[i] <= u, with the guarantee that i < count - 1 for in-range queries.
int	getPointCount()
float[]	getTimes01()
float[]	getValues()
private static float	lerp(float a, float b, float u)
float	sample(float u)	Sample the control curve at parameter u ∈ [0,1].
float	sampleUnit(float u)	Convenience for dynamics-style use where values are expected in [0,1].
private static void	validate(float[] times01, float[] values)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

times01

private final float[] times01

values

private final float[] values

count

private final int count

Constructor Details

PAKeyframeControlCurve

public PAKeyframeControlCurve(float[] times01,
 float[] values)

Parameters:

times01 - strictly ascending control times in [0,1]

values - scalar values corresponding to each entry in times01

Method Details

getPointCount

public int getPointCount()

Returns:

number of keyframes

getTimes01

public float[] getTimes01()

Returns:

defensive copy of normalized keyframe times

getValues

public float[] getValues()

Returns:

defensive copy of keyframe values

sample

public float sample(float u)

Sample the control curve at parameter u ∈ [0,1]. Values outside [0,1] are clamped before sampling.

Specified by:

sample in interface PAControlCurve

sampleUnit

public float sampleUnit(float u)

Convenience for dynamics-style use where values are expected in [0,1]. The returned sample is clamped to [0,1].

Parameters:

u - value to clamp to interval [0,1]

Returns:

value clamped to [0,1]

findSegment

private int findSegment(float u)

Find the largest i such that times01[i] <= u, with the guarantee that i < count - 1 for in-range queries.

Parameters:

u - find largest index in times01[] that is less than u

Returns:

largest index less than u over times01[]

validate

private static void validate(float[] times01,
 float[] values)

clamp01

private static float clamp01(float u)

lerp

private static float lerp(float a,
 float b,
 float u)

expandToSchedule

public static float[] expandToSchedule(PAControlCurve curve,
 GestureSchedule sched)