import jm.audio.io.SampleOut;
import jm.audio.synth.Envelope;
import jm.audio.synth.Oscillator;
import jm.audio.synth.StereoPan;
import jm.audio.synth.Volume;
/**
* A basic additive synthesis jMusic instrument implementation
* which implements envelope and volume control
*
* @author Andrew Sorensen
*/
public final class SineInst extends jm.audio.Instrument {
//----------------------------------------------
// Attributes
//----------------------------------------------
/**
* The number of channels
*/
private int channels;
/**
* the sample rate passed to the instrument
*/
private int sampleRate;
/**
* The pitch in hertz of a fixed frequency oscillator
*/
private float frequency = -1.0f;
/**
* The bereak point values fo the amplitude envelope
*/
private double[] envPoints;
private SampleOut sout;
//----------------------------------------------
// Constructor
//----------------------------------------------
/**
* Basic default constructor that creates
* a stereo signal at 44100 hz.
*/
public SineInst() {
this(44100, 2);
}
/**
* Basic default constructor to set an initial
* sampling rate.
*
* @param sampleRate
*/
public SineInst(int sampleRate) {
this(sampleRate, 2);
}
/**
* A constructor to set an initial
* sampling rate and number of channels.
*
* @param sampleRate
* @param channels the number of channels in the sound 1 = mono, 2 = stereo, etc
*/
public SineInst(int sampleRate, int channels) {
this(sampleRate, channels, new double[]{
0.0, 0.0,
0.15, 1.0,
0.3, 0.5,
1.0, 0.0});
}
/**
* A constructor to set sampleRate, channels, and
* the pitch of the sine wave in hertz.
*
* @param sampleRate
* @param channels the number of channels in the sound 1 = mono, 2 = stereo, etc
* @param points The bereak point values fo the amplitude envelope
*/
public SineInst(int sampleRate, int channels, double[] points) {
this(sampleRate, channels, points, -1.0f);
}
/**
* A constructor to set sampleRate, channels, and
* the pitch of the sine wave in hertz.
*
* @param sampleRate
* @param channels the number of channels in the sound 1 = mono, 2 = stereo, etc
* @param points The bereak point values fo the amplitude envelope
* @param frequency a positive float value specifying a fixed pitch
*/
public SineInst(int sampleRate, int channels, double[] points, float frequency) {
this.sampleRate = sampleRate;
this.channels = channels;
this.frequency = frequency;
this.envPoints = points;
}
//----------------------------------------------
// Methods
//----------------------------------------------
/**
* Specify a fixed frequency oscillator.
*
* @param The frequency in hertz
*/
public void setFrequency(float freq) {
this.frequency = freq;
}
/**
* Specify a particular envelope.
*
* @param newValues The array of time percent, amplitude pairs of double values.
*/
public void setEnvPoints(double[] newValues) {
this.envPoints = newValues;
}
/**
* Initialisation method used to build the objects that
* this instrument will use.
*/
public void createChain() {
Oscillator osc = new Oscillator(this, Oscillator.SINE_WAVE, this.sampleRate, this.channels);
// set a fixed, rather the note determined, frequency
if (frequency != -1.0f) {
osc.setChoice(0);
osc.setFrq(frequency);
}
Envelope env = new Envelope(osc, envPoints);
Volume vol = new Volume(env);
StereoPan span = new StereoPan(vol);
if (output == RENDER) sout = new SampleOut(span);
}
}