//Chaos.java
//generalizatin of Sierpinski triangle
import java.awt.*;
import java.awt.event.*;   //ActionListener interface
import javax.swing.*;

public class Chaos extends JApplet implements ActionListener {
    
    JLabel verticesLabel, xLabel, yLabel, distanceLabel, loopsLabel;
    JTextField verticesField, xField, yField, distanceField, loopsField;
    JButton againButton, verticesButton;
    int [] px;
    int [] py;

    public void init() {

	Container container = getContentPane();  
	container.setLayout( new FlowLayout() ); 
	
	verticesLabel = new JLabel( "Number of vertices" );
	container.add( verticesLabel );
	verticesField = new JTextField( "3", 3 );
	container.add( verticesField );
	
	xLabel = new JLabel( "starting X" );
	container.add( xLabel );
	xField = new JTextField( ""+(int)(getWidth()/2), 4 );
	container.add( xField );

	yLabel = new JLabel( "starting Y" );
	container.add( yLabel );
	yField = new JTextField( ""+(int)(getHeight()/2), 4 );
	container.add( yField );

	distanceLabel = new JLabel( "Distance" );
	container.add( distanceLabel );
	distanceField = new JTextField( "0.5", 4 );
	container.add( distanceField );

	loopsLabel = new JLabel( "Iterations" );
	container.add( loopsLabel );
	loopsField = new JTextField( "1000", 4 );
	container.add( loopsField );

	againButton = new JButton( "Again" );
	container.add( againButton );
	againButton.addActionListener( this );

	verticesButton = new JButton( "New vertices" );
	container.add( verticesButton );
	verticesButton.addActionListener( this );

	int vertices = Integer.parseInt(verticesField.getText());
	px = new int[vertices];
	py = new int[vertices];
	for (int i=0; i<px.length; i++) {
	    px[i] = (int)(Math.random()*getWidth());
	    py[i] = (int)(Math.random()*getHeight());
	}

    }

    public void actionPerformed( ActionEvent event ) {

	if (event.getSource()==againButton || 
	    event.getSource()==verticesButton) { 

	    int vertices = Integer.parseInt(verticesField.getText());
	    if (vertices != px.length) {
		px = new int[vertices];
		py = new int[vertices];
		if ( event.getSource() == againButton ) {
		    for (int i=0; i<px.length; i++) {
			px[i] = (int)(Math.random()*getWidth());
			py[i] = (int)(Math.random()*getHeight());
		    }
		    repaint();    
		    return;  //quit this call  ??
		}
	    }
	}

	if ( event.getSource() == againButton )   //#vertices did not change
	    repaint();
	else if ( event.getSource() == verticesButton ) {
	    for (int i=0; i<px.length; i++) {
		px[i] = (int)(Math.random()*getWidth());
		py[i] = (int)(Math.random()*getHeight());
	    }
	    repaint();    
	}
    }
    
    
    public void paint( Graphics g ) {
	double distance;
	int loops;
	int sx, sy;
	int vertices;
	
	super.paint( g );
	
	distance =  Double.parseDouble(distanceField.getText());
	vertices =  Integer.parseInt(verticesField.getText());
	sx =  Integer.parseInt(xField.getText());
	sy =  Integer.parseInt(yField.getText());
	loops = Integer.parseInt(loopsField.getText());
	

	g.setColor(Color.RED);

	//random vertices...
	for (int i=0; i<px.length; i++) {
	    g.fillOval(px[i],py[i],2,3);
	}

	g.setColor(Color.BLACK);

	//move distance percent toward random vertex
	for (int i=1; i<=loops; i++) {
	    int p = (int)(Math.random() * vertices);
	    sx = (int)((px[p] + sx) * distance);
	    sy = (int)((py[p] + sy) * distance);
	    g.fillOval(sx,sy,2,2);
	}

    }
}