com.jsyn.data

Class SegmentedEnvelope

java.lang.Object

com.jsyn.data.SequentialDataCommon

com.jsyn.data.SegmentedEnvelope

All Implemented Interfaces:

SequentialData

public class SegmentedEnvelope
extends SequentialDataCommon

Store an envelope as a series of line segments. Each line is described as a duration and a target value. The envelope can be played using a VariableRateMonoReader. Here is an example that generates an envelope that looks like a traditional ADSR envelope.

 
        // Create an amplitude envelope and fill it with data.
        double[] ampData = {
                0.02, 0.9, // duration,value pair 0, "attack"
                0.10, 0.5, // pair 1, "decay"
                0.50, 0.0  // pair 2, "release"
        };
        SegmentedEnvelope ampEnvelope = new SegmentedEnvelope( ampData );
        
        // Hang at end of decay segment to provide a "sustain" segment.
        ampEnvelope.setSustainBegin( 1 );
        ampEnvelope.setSustainEnd( 1 );
        
        // Play the envelope using queueOn so that it uses the sustain and release information.
        synth.add( ampEnv = new VariableRateMonoReader() );
        ampEnv.dataQueue.queueOn( ampEnvelope );
 
 

As an alternative you could use an EnvelopeDAHDSR.

Author:

Phil Burk (C) 2010 Mobileer Inc

See Also:

VariableRateMonoReader, EnvelopeDAHDSR

Field Summary

Fields inherited from class com.jsyn.data.SequentialDataCommon

maxFrames, numFrames

Constructor Summary

Constructors

Constructor and Description
SegmentedEnvelope(double[] pairs)
SegmentedEnvelope(int maxFrames)

Method Summary

Modifier and Type	Method and Description
void	allocate(int maxFrames)
int	getChannelsPerFrame()
double	getRateScaler(int index, double synthesisPeriod) Get rate to play the data.
void	read(double[] data)
void	read(int startFrame, double[] data, int startIndex, int numToRead)
double	readDouble(int index) Read the value of an envelope, not the duration.
void	write(double[] data)
void	write(int startFrame, double[] data, int startIndex, int numToWrite) Write frames of envelope data.
void	writeDouble(int index, double value) Write a value at the given index.

Methods inherited from class com.jsyn.data.SequentialDataCommon

getMaxFrames, getNumFrames, getReleaseBegin, getReleaseEnd, getSustainBegin, getSustainEnd, setNumFrames, setReleaseBegin, setReleaseEnd, setSustainBegin, setSustainEnd

Methods inherited from class java.lang.Object

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

Constructor Detail

SegmentedEnvelope

public SegmentedEnvelope(int maxFrames)

SegmentedEnvelope

public SegmentedEnvelope(double[] pairs)

Method Detail

allocate

public void allocate(int maxFrames)

write

public void write(int startFrame,
                  double[] data,
                  int startIndex,
                  int numToWrite)

Write frames of envelope data. A frame consists of a duration and a value.

Parameters:

startFrame - Index of frame in envelope to write to.

data - Pairs of duration and value.

startIndex - Index of frame in data[] to read from.

numToWrite - Number of frames (pairs) to write.

read

public void read(int startFrame,
                 double[] data,
                 int startIndex,
                 int numToRead)

write

public void write(double[] data)

read

public void read(double[] data)

readDouble

public double readDouble(int index)

Read the value of an envelope, not the duration.

Specified by:

readDouble in interface SequentialData

Specified by:

readDouble in class SequentialDataCommon

Parameters:

index - sample index is ((frameIndex * channelsPerFrame) + channelIndex)

writeDouble

public void writeDouble(int index,
                        double value)

Description copied from interface: SequentialData

Write a value at the given index.

Specified by:

writeDouble in interface SequentialData

Specified by:

writeDouble in class SequentialDataCommon

Parameters:

index - sample index is ((frameIndex * channelsPerFrame) + channelIndex)

value - the value to be written

getRateScaler

public double getRateScaler(int index,
                            double synthesisPeriod)

Description copied from interface: SequentialData

Get rate to play the data. In an envelope this correspond to the inverse of the frame duration and would vary frame to frame. For an audio sample it is 1.0.

Specified by:

getRateScaler in interface SequentialData

Specified by:

getRateScaler in class SequentialDataCommon

Returns:

rate to scale the playback speed.

getChannelsPerFrame

public int getChannelsPerFrame()

Specified by:

getChannelsPerFrame in interface SequentialData

Specified by:

getChannelsPerFrame in class SequentialDataCommon

Returns:

For a stereo sample, return 2.