/******************************************************************
 *
 *  Mandelbrot program written 5/23/2000, Marcus C. Sarofim
 *
 *  Still to be implemented:
 *		User ability to set "iterFactor" (should call "iterfactor")
 *		and "iterbase" (currently default 50).
 *		Magfactor should default to log base 100 of magnification + 1.
 *			 For user change, need radio box.
 *
 *******************************************************************/

import java.awt.*;
import java.applet.Applet;
import java.awt.event.*;
import java.applet.*;

public class Mandelbrot extends Applet implements ActionListener, MouseListener, ItemListener
{
	private double shiftx, shifty;
	private double magnification;
	private double iterFactor;
	private float iterBase=75;
	private Checkbox userIter;
	private TextField iterField;
	private boolean userIterp=false;

	
	public void init()
	{
		userIter=new Checkbox("UserIter");
		add(userIter);
		userIter.addItemListener(this);
		iterField=new TextField(4);
		add(iterField);
		iterField.addActionListener(this);
		iterField.setText("75");
		shiftx=shifty=0;
		magnification=1;
		iterFactor=1;
		this.addMouseListener(this);
	}
	
	public void paint(Graphics g)
	{
		g.drawString("shiftx: "+shiftx+" shifty: "+shifty,20,500); 
		g.drawString("magnification: "+magnification+" iteractions: "
		+(int)(iterFactor*iterBase),20,540);
		for (int x=-100; x<200; x++)
		{
			for (int y=-200; y<200; y++)
			{
				double temp=0, othertemp=0;;
				double xorig, yorig;
				double xold = x/(100*magnification)+shiftx/100;
				double yold = y/(100*magnification)+shifty/100;
				xorig=xold;
				yorig=yold;
				double xnew, ynew;
				for(int q=0; (q<iterBase*iterFactor)&&(temp<100); q++)
				{
					xnew=xold*xold-yold*yold-xorig;
					ynew=2*xold*yold-yorig;
					xold=xnew;
					yold=ynew;
					temp=xnew*xnew+ynew*ynew;
					othertemp=q;
				}
				if (temp<99)
				{
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.95)
				{
					g.setColor(new Color(0.5f,0.1f,1.0f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.9)
				{
					g.setColor(new Color(0.45f,0.0f,1.0f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.8)
				{
					g.setColor(new Color(0.38f,0.0f,0.97f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.7)
				{
					g.setColor(new Color(0.32f,0.0f,0.92f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.6)
				{
					g.setColor(new Color(0.24f,0.0f,0.84f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.5)
				{
					g.setColor(new Color(0.18f,0.0f,0.75f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.4)
				{
					g.setColor(new Color(0.14f,0.0f,0.67f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.3)
				{
					g.setColor(new Color(0.11f,0.0f,0.61f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.2)
				{
					g.setColor(new Color(0.09f,0.0f,0.57f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				else if (othertemp>iterBase*iterFactor*.1)
				{
					g.setColor(new Color(0.05f,0.0f,0.51f));
					g.drawLine(x+150, y+250, x+150, y+250);
				}
				g.setColor(Color.black);
			}
		}
	}
	
	public void actionPerformed(ActionEvent event)
	{
		if (event.getSource()==iterField)
		{
			iterBase=Integer.parseInt(iterField.getText());
			repaint();
		}
		
	}
	
	public void itemStateChanged(ItemEvent e)
	{
		if (e.getSource()==userIter)
		{
			userIterp = userIter.getState();
			if (userIterp) iterFactor=1;
			else iterFactor=1+Math.log(magnification)/4.6;
			repaint();
		}
	}
	
	public void mouseClicked(MouseEvent event)
	{
	}
	
	public void mouseReleased(MouseEvent event)
	{
	}
	
	public void mousePressed(MouseEvent event)
	{
		int yCoord = event.getY();
		int xCoord = event.getX();
		if ((yCoord<450)&&(yCoord>50)&&(xCoord<350)&&(xCoord>50))
		{
			shiftx+=(xCoord-150)/magnification;
			shifty+=(yCoord-250)/magnification;
			magnification = 2*magnification;
			
			if (!userIterp)
			{
				iterFactor = 1+Math.log(magnification)/4.6;
			}
			else
			{
				iterFactor = 1;
			}
			repaint();
		}
	}
	
	public void mouseEntered(MouseEvent event)
	{
	}
	
	public void mouseExited(MouseEvent event)
	{
	}
}