net.beadsproject.beads.ugens

Class LPRezFilter

java.lang.Object

net.beadsproject.beads.core.Bead

net.beadsproject.beads.core.UGen

net.beadsproject.beads.ugens.IIRFilter

net.beadsproject.beads.ugens.LPRezFilter

All Implemented Interfaces:

DataBeadReceiver

public class LPRezFilter
extends IIRFilter
implements DataBeadReceiver

A simple 2nd-order resonant low-pass filter optimized for single-channel processing. Faster than a BiquadFilter because its algorithm is of the form:

y(n) = b0 * x(n) + a1 * y(n-1) + a2 * y(n-2)

so it doesn't compute unnecessary parts of the biquad formula.

Takes two parameters: cut-off frequency and resonance (0 for no resonance, 1 for maximum resonance). These parameters can be set using setFreq() and setRes(), or by passing a DataBead with "frequency" and "resonance" properties to setParams(DataBead). (Messaging this object with a DataBead achieves the same.)

Version:

0.9.5

Author:

Benito Crawford

Nested Class Summary

Nested classes/interfaces inherited from class net.beadsproject.beads.ugens.IIRFilter

IIRFilter.IIRFilterAnalysis

Nested classes/interfaces inherited from class net.beadsproject.beads.core.UGen

UGen.OutputInitializationRegime, UGen.OutputPauseRegime

Field Summary

Fields

Modifier and Type	Field and Description
protected float	_2pi_over_sr
protected float	a1
protected float	a2
protected float	b0
protected float	cosw
protected float	freq
protected UGen	freqUGen
protected boolean	isFreqStatic
protected boolean	isResStatic
protected float	res
protected UGen	resUGen

Fields inherited from class net.beadsproject.beads.core.UGen

bufferSize, bufIn, bufOut, context, ins, outputInitializationRegime, outputPauseRegime, outs

Constructor Summary

Constructors

Constructor and Description
LPRezFilter(AudioContext con) Constructor for a single-channel LPRezFilter with default values for frequency and resonance.
LPRezFilter(AudioContext con, float freq, float res) Constructor for a single-channel LPRezFilter with frequency and resonance specified by floats.
LPRezFilter(AudioContext con, float freq, UGen res) Constructor for a single-channel LPRezFilter with frequency specified by a float and resonance specified by a UGen.
LPRezFilter(AudioContext con, int channels) Constructor for a multi-channel LPRezFilter with default values for frequency and resonance.
LPRezFilter(AudioContext con, int channels, float freq, float res) Constructor for a multi-channel LPRezFilter with frequency and resonance specified by floats.
LPRezFilter(AudioContext con, int channels, float freq, UGen res) Constructor for a multi-channel LPRezFilter with frequency specified by a float and resonance specified by a UGen.
LPRezFilter(AudioContext con, int channels, UGen freq, float res) Constructor for a multi-channel LPRezFilter with frequency specified by a UGen and resonance specified by a float.
LPRezFilter(AudioContext con, int channels, UGen freq, UGen res) Constructor for a multi-channel LPRezFilter with frequency and resonance specified by UGens.
LPRezFilter(AudioContext con, UGen freq, float res) Constructor for a single-channel LPRezFilter with frequency specified by a UGen and resonance specified by a float.
LPRezFilter(AudioContext con, UGen freq, UGen res) Constructor for a single-channel LPRezFilter with frequency and resonance specified by UGens.

Method Summary

Modifier and Type	Method and Description
void	calculateBuffer() Called by the signal chain to update this UGen's ouput data.
protected void	calcVals()
IIRFilter.IIRFilterAnalysis	getFilterResponse(float freq)
float	getFreq() Deprecated. Use getFrequency().
float	getFrequency() Gets the current cut-off frequency.
UGen	getFrequencyUGen() Gets the frequency UGen, if it exists.
UGen	getFreqUGen() Deprecated. Use getFrequencyUGen().
DataBead	getParams() Gets a DataBead with properties "frequency" and "resonance" set to the corresponding filter parameters.
float	getRes() Gets the current resonance value.
UGen	getResUGen() Gets the resonance UGen, if it exists.
DataBead	getStaticParams() Gets a DataBead with properties "frequency" and "resonance" set to static float values corresponding to the current filter parameters.
void	messageReceived(Bead message) Responds to an incoming message.
void	reset() Resets the filter in case it "explodes".
DataBeadReceiver	sendData(DataBead db) Sets the filter's parameters with properties from a DataBead.
LPRezFilter	setFreq(float freq) Deprecated. Use setFrequency(float).
LPRezFilter	setFreq(UGen freqUGen) Deprecated. Use setFrequency(UGen).
LPRezFilter	setFrequency(float freq) Sets the cut-off frequency to a float.
LPRezFilter	setFrequency(UGen freqUGen) Sets a UGen to specify the cut-off frequency.
LPRezFilter	setParams(DataBead paramBead) Sets the filter parameters with a DataBead.
LPRezFilter	setRes(float r) Sets the filter resonance to a float value.
LPRezFilter	setRes(UGen r) Sets a UGen to specify the filter resonance.

Methods inherited from class net.beadsproject.beads.ugens.IIRFilter

analyzeFilter, calculateFilterResponse, calculateGroupDelay, getAmplitudeResponse, getGroupDelay, getPhaseDelay, getPhaseResponse

Methods inherited from class net.beadsproject.beads.core.UGen

addDependent, addInput, addInput, clearDependents, clearInputConnections, containsInput, crossfadeInput, getConnectedInputs, getContext, getEnvelopes, getIns, getNumberOfConnectedUGens, getNumberOfDependents, getOutBuffer, getOuts, getTimeTakenLastUpdate, getValue, getValue, getValueDouble, getValueDouble, initializeOuts, isTimerMode, isUpdated, noInputs, pause, printInBuffers, printInputList, printOutBuffers, removeAllConnections, removeConnection, removeDependent, setOutsToPause, setTimerMode, setValue, update, zeroIns, zeroOuts

Methods inherited from class net.beadsproject.beads.core.Bead

getKillListener, getName, isDeleted, isPaused, kill, message, setKillListener, setName, start, toString

Methods inherited from class java.lang.Object

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

Field Detail

freq

protected float freq

res

protected float res

_2pi_over_sr

protected float _2pi_over_sr

cosw

protected float cosw

freqUGen

protected UGen freqUGen

resUGen

protected UGen resUGen

a1

protected float a1

a2

protected float a2

b0

protected float b0

isFreqStatic

protected boolean isFreqStatic

isResStatic

protected boolean isResStatic

Constructor Detail

LPRezFilter

public LPRezFilter(AudioContext con)

Constructor for a single-channel LPRezFilter with default values for frequency and resonance.

Parameters:

con - The audio context.

LPRezFilter

public LPRezFilter(AudioContext con,
                   int channels)

Constructor for a multi-channel LPRezFilter with default values for frequency and resonance.

Parameters:

con - The audio context.

channels - The number of channels.

LPRezFilter

public LPRezFilter(AudioContext con,
                   float freq,
                   float res)

Constructor for a single-channel LPRezFilter with frequency and resonance specified by floats.

Parameters:

con - The audio context.

freq - The filter cut-off frequency.

res - The resonance.

LPRezFilter

public LPRezFilter(AudioContext con,
                   UGen freq,
                   float res)

Constructor for a single-channel LPRezFilter with frequency specified by a UGen and resonance specified by a float.

Parameters:

con - The audio context.

freq - The filter cut-off frequency UGen.

res - The resonance.

LPRezFilter

public LPRezFilter(AudioContext con,
                   float freq,
                   UGen res)

Constructor for a single-channel LPRezFilter with frequency specified by a float and resonance specified by a UGen.

Parameters:

con - The audio context.

freq - The filter cut-off frequency.

res - The resonance UGen.

LPRezFilter

public LPRezFilter(AudioContext con,
                   UGen freq,
                   UGen res)

Constructor for a single-channel LPRezFilter with frequency and resonance specified by UGens.

Parameters:

con - The audio context.

freq - The filter cut-off frequency UGen.

res - The resonance UGen.

LPRezFilter

public LPRezFilter(AudioContext con,
                   int channels,
                   float freq,
                   float res)

Constructor for a multi-channel LPRezFilter with frequency and resonance specified by floats.

Parameters:

con - The audio context.

channels - The number of channels.

freq - The filter cut-off frequency.

res - The resonance.

LPRezFilter

public LPRezFilter(AudioContext con,
                   int channels,
                   UGen freq,
                   float res)

Constructor for a multi-channel LPRezFilter with frequency specified by a UGen and resonance specified by a float.

Parameters:

con - The audio context.

channels - The number of channels.

freq - The filter cut-off frequency UGen.

res - The resonance.

LPRezFilter

public LPRezFilter(AudioContext con,
                   int channels,
                   float freq,
                   UGen res)

Constructor for a multi-channel LPRezFilter with frequency specified by a float and resonance specified by a UGen.

Parameters:

con - The audio context.

channels - The number of channels.

freq - The filter cut-off frequency.

res - The resonance UGen.

LPRezFilter

public LPRezFilter(AudioContext con,
                   int channels,
                   UGen freq,
                   UGen res)

Constructor for a multi-channel LPRezFilter with frequency and resonance specified by UGens.

Parameters:

con - The audio context.

channels - The number of channels.

freq - The filter cut-off frequency UGen.

res - The resonance UGen.

Method Detail

calcVals

protected void calcVals()

calculateBuffer

public void calculateBuffer()

Description copied from class: UGen

Called by the signal chain to update this UGen's ouput data. Subclassses of UGen should implement the UGen's DSP perform routine here. In general this involves grabbing data from UGen.bufIn and putting data into UGen.bufOut in some way. UGen.bufIn and UGen.bufOut are 2D arrays of floats of the form float[numChannels][bufferSize]. The length of the buffers is given by UGen.bufferSize, and the number of channels of the input and output buffers are given by UGen.ins and UGen.outs respectively.

Specified by:

calculateBuffer in class UGen

reset

public void reset()

Resets the filter in case it "explodes".

getFrequency

public float getFrequency()

Gets the current cut-off frequency.

Returns:

The cut-off frequency.

setFrequency

public LPRezFilter setFrequency(float freq)

Sets the cut-off frequency to a float. Removes the frequency UGen, if there is one.

Parameters:

freq - The cut-off frequency.

Returns:

This filter instance.

setFrequency

public LPRezFilter setFrequency(UGen freqUGen)

Sets a UGen to specify the cut-off frequency. Passing a null value freezes the parameter.

Parameters:

freqUGen - The frequency UGen.

Returns:

This filter instance.

getFrequencyUGen

public UGen getFrequencyUGen()

Gets the frequency UGen, if it exists.

Returns:

The frequency UGen.

getFreq

@Deprecated
public float getFreq()

Deprecated. Use getFrequency().

Gets the current cut-off frequency.

Returns:

The cut-off frequency.

setFreq

@Deprecated
public LPRezFilter setFreq(float freq)

Deprecated. Use setFrequency(float).

Sets the cut-off frequency to a float. Removes the frequency UGen, if there is one.

Parameters:

freq - The cut-off frequency.

Returns:

This filter instance.

setFreq

@Deprecated
public LPRezFilter setFreq(UGen freqUGen)

Deprecated. Use setFrequency(UGen).

Sets a UGen to specify the cut-off frequency. Passing a null value freezes the parameter.

Parameters:

freqUGen - The frequency UGen.

Returns:

This filter instance.

getFreqUGen

@Deprecated
public UGen getFreqUGen()

Deprecated. Use getFrequencyUGen().

Gets the frequency UGen, if it exists.

Returns:

The frequency UGen.

getRes

public float getRes()

Gets the current resonance value.

Returns:

The resonance.

setRes

public LPRezFilter setRes(float r)

Sets the filter resonance to a float value. This removes the resonance UGen, if it exists. (Should be >= 0 and < 1.)

Parameters:

r - The resonance.

Returns:

This filter instance.

setRes

public LPRezFilter setRes(UGen r)

Sets a UGen to specify the filter resonance. Passing a null value freezes the parameter.

Parameters:

r - The resonance UGen.

Returns:

This filter instance.

getResUGen

public UGen getResUGen()

Gets the resonance UGen, if it exists.

Returns:

The resonance UGen.

setParams

public LPRezFilter setParams(DataBead paramBead)

Sets the filter parameters with a DataBead.

Use the following properties to specify filter parameters:

• "frequency": (float or UGen)
• "resonance": (float or UGen)

Parameters:

paramBead - The DataBead specifying parameters.

Returns:

This filter instance.

messageReceived

public void messageReceived(Bead message)

Description copied from class: Bead

Responds to an incoming message. Subclasses can override this in order to handle incoming messages. Typically a Bead would send a message to another Bead with itself as the arugment.

Overrides:

messageReceived in class Bead

Parameters:

message - the message

getParams

public DataBead getParams()

Gets a DataBead with properties "frequency" and "resonance" set to the corresponding filter parameters.

Returns:

The parameter DataBead.

getStaticParams

public DataBead getStaticParams()

Gets a DataBead with properties "frequency" and "resonance" set to static float values corresponding to the current filter parameters.

Returns:

The static parameter DataBead.

sendData

public DataBeadReceiver sendData(DataBead db)

Sets the filter's parameters with properties from a DataBead.

Specified by:

sendData in interface DataBeadReceiver

Parameters:

db - The DataBead message.

Returns:

Typically, the object instance: this.

See Also:

setParams(DataBead)

getFilterResponse

public IIRFilter.IIRFilterAnalysis getFilterResponse(float freq)

Specified by:

getFilterResponse in class IIRFilter