import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import shtick.math.Complex;

//////////////////////////////////////////////////////
//**************************************************//
//*               Mandelbrot Applet                *//
//*                                                *//
//* Version 1.2.1                                  *//
//* Author: Sean M. Cox                            *//
//* Organization: The Shtick                       *//
//* http://www.smcox.com/                          *//
//*                                                *//
//* Renders a Mandelbrot fractal and demonstrates  *//
//* the usage of complex numbers.                  *//
//*                                                *//
//**************************************************//
//////////////////////////////////////////////////////

public class Mandelbrot extends Applet{
  int     pixels[];
  int     domain;
  int     range;

  boolean renderNew=true;
  Image   fractal;
  long    time;
  String  error="Uncertain";

  public Mandelbrot(){}

  public void paintFractal(Graphics g){
    double xUnit=(double)4/domain;
    double yUnit=(double)4/range;
    double y=yUnit/2-2;
    final int colorInc=0x060606;
    for(int py=0;py<range;py++){
      double x=xUnit/2-2;
      for(int px=0;px<domain;px++){
        Complex c=new Complex(x,y);
        Complex z=new Complex(0,0);
        int n;
        for(n=0;(Math.abs(z.doubleValueReal())<2)&&(Math.abs(z.doubleValueImaginary())<2)&&(n<32);n++){
          z.pow(2);
          z.add(c);
        }
        pixels[py*domain+px]=(colorInc*n)|0xFF000000;
        x+=xUnit;
      }//for
      y+=yUnit;
    }//for
    fractal=this.createImage(new MemoryImageSource(domain,range,pixels,0,domain));
  }

  public void resize(int width,int height){
    super.resize(width,height);
    domain=width;
    range=height;
    pixels=new int[width*height];
  }

  public void update(Graphics g){
    paint(g);
  }

  public void paint(Graphics g){
    if (fractal==null){
      time=System.currentTimeMillis();
      paintFractal(getGraphics());
      renderNew=false;
      time=System.currentTimeMillis()-time;
    }
    g.drawImage(fractal,0,0,this);
    g.setColor(Color.white);
    g.drawString(String.valueOf(time),2,15);
  }
}