package com.softsynth.jsyn.circuits;
import java.util.*;
import java.awt.*;
import java.applet.Applet;
import com.softsynth.jsyn.*;

/**
 * Bell generated by ring modulating two triangle waves.
 * Ring modulation simply involves multiplying two signals together.
 * 
 * Output = Osc2.output * ( (Osc1.output * ExpLag.output) + ExpLag.output);
 * Osc1.Frequency = Osc2.frequency * modIndex;
 *
 * @author (C) 1997 Phil Burk, SoftSynth.com, All Rights Reserved
 */

public class RingModBell extends SynthNote
{
	public TriangleOscillator  osc1, osc2;
	public ExponentialLag      expLag;
	public MultiplyUnit        freqScalar;
	public MultiplyUnit        ringMod;
	public AddUnit             ampMixer;

/* Declare ports. */
	public SynthInput          modIndex; /* Ratio of frequency of two oscillators. */
	public SynthVariable       halfLife; /* Decay time for exponential envelope. */

/*
 * Setup synthesis.
 */
	public RingModBell()  throws SynthException
	{
/* Create various unit generators and add them to circuit. */
		add( osc1       = new TriangleOscillator() );
		add( osc2       = new TriangleOscillator() );
		add( ampMixer   = new AddUnit() );
		add( expLag     = new ExponentialLag() );
		add( freqScalar = new MultiplyUnit() );
		add( ringMod    = new MultiplyUnit() );

/* Make ports on internal units appear as ports on circuit. */ 
		addPort( amplitude = osc2.amplitude );
		addPort( modIndex = freqScalar.inputB, "modIndex" );
		addPort( halfLife = expLag.halfLife );
		addPort( output = ringMod.output );
		
/* Make a virtual port that connects to several internal ports. */
/* Set signal type for frequency control so that we can operate in hertz. */
/* Use the predefined frequency port from the SynthNote class. */
		frequency = new SynthDistributor( this, "frequency", Synth.SIGNAL_TYPE_OSC_FREQ );
		
/* Ring modulate osc1 and osc2 to get bell like sounds.
 * Output = Osc2.output * ( (Osc1.output * ExpLag.output) + ExpLag.output);
 * Osc1.Frequency = Osc2.frequency * modIndex;
 */
		osc2.output.connect( ringMod.inputA );
		ampMixer.output.connect( ringMod.inputB );

		expLag.output.connect( ampMixer.inputA );
		expLag.output.connect( osc1.amplitude );
		osc1.output.connect( ampMixer.inputB );

		frequency.connect( osc2.frequency );
		frequency.connect( freqScalar.inputA );
		freqScalar.output.connect( osc1.frequency );

		frequency.setup(0.0, 5000.0, 10000.0 );
		modIndex.set( 4.0/5.0 );
		amplitude.set(0.5);
		halfLife.setup(0.0, 0.2, 1.0);

	}

	public void setStage( int time, int stage )  throws SynthException
	{
		switch( stage )
		{
		case 0: 
			double half = halfLife.get();
/* Spike up, then go down slowly. */
			expLag.halfLife.set( time, 0.001 );
			expLag.input.set( time, 0.5 );
			expLag.halfLife.set( time + 20, half );
			expLag.input.set( time + 20, 0.0 );
			start( time );
			break;
		default:
			break;
		}
	}

}