import jm.audio.AOException;
import jm.audio.AudioObject;
import jm.audio.io.SampleOut;
import jm.audio.synth.*;
/**
* A basic FM synthesis instrument implementation
*
* @author Andrew Sorensen
*/
public final class SimpleFMInst extends jm.audio.Instrument {
//----------------------------------------------
// Attributes
//---------------------------------------------
/**
* The number of channels
*/
private int channels;
/**
* The modulation index
*/
private int modIndex;
/**
* The frequency ratio from the carrier frequency (the notes pitch)
*/
private float frqRatio;
private int sampleRate;
//----------------------------------------------
// Constructor
//----------------------------------------------
/**
* Basic default constructor to set basic values
*
* @param sampleRate The instrument's audio resolution
* @param modIndex The modulation index, greater = more overtones
* @param ratio The carrier/modulator pitch ratio = harmonicity of spectrum
*/
public SimpleFMInst(int sampleRate, int modIndex, double ratio) {
this(sampleRate, modIndex, ratio, 1);
}
/**
* A constructor to set all values
*
* @param sampleRate The instrument's audio resolution
* @param modIndex The modulation index, greater = more overtones
* @param ratio The carrier/modulator pitch ratio = harmonicity of spectrum
* @param channels The number of channels
*/
public SimpleFMInst(int sampleRate, int modIndex, double ratio, int channels) {
this.sampleRate = sampleRate;
this.channels = channels;
this.modIndex = modIndex;
this.frqRatio = (float) ratio;
}
//----------------------------------------------
// Methods
//----------------------------------------------
/**
* Initialisation method used to build the objects that
* this instrument will use
*/
public void createChain() throws AOException {
// modulator
Oscillator modulator = new Oscillator(this, Oscillator.SINE_WAVE, this.sampleRate, this.channels);
modulator.setFrqRatio(frqRatio);
modulator.setAmp((float) modIndex);
Envelope env = new Envelope(modulator, new double[]{0.0, 1.0, 1.0, 0.0});
// constant
Value constFreq = new Value(this, this.sampleRate, this.channels, Value.NOTE_PITCH);
Add add = new Add(new AudioObject[]{constFreq, env});
// carrier
Oscillator carrier = new Oscillator(add, Oscillator.SINE_WAVE, Oscillator.FREQUENCY);
Envelope ampEnv = new Envelope(carrier, new double[]{0.0, 0.0, 0.02, 1.0, 1.0, 0.0});
Volume amp = new Volume(ampEnv);
StereoPan pan = new StereoPan(amp);
SampleOut sout = new SampleOut(pan);
}
}