/** A class of Mandelbrot Set objects */
import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import java.lang.*;
import java.awt.event.*;

public class MandelbrotSet
{
    private Complex ll;         // lower left corner of region
    private double  edge;       // edge lengthh of region
    private int     res,        // resolution: discretize region
                                //  into a grid of res X res squares
                                // res & atom must be powers of 2
                    clr,        // # bits or red, green, blue
                    cnt[][];    // iteration count for each "point"

    public MandelbrotSet(Complex c, double e, int r, int b)
    {
        ll = new Complex(c);
        edge = e;
        res = r;
        clr = b;
        cnt = new int[res][res];
    }

    public void compute()
    {
        double gap = edge/res,   // space between grid "points"
               r, i;             // the representative point
        int row, col,
            lim = (int) Math.pow(2,clr); // iteration limit

        for (row = 0, i = ll.getImag(); row < res; row++, i += gap)
        for (col = 0, r = ll.getReal(); col < res; col++, r += gap)
            cnt[row][col] = getCount(new Complex(r, i), lim);
    }

    // compute the count associated with a complex point
    final private int getCount(Complex c, int lim)
    {
        Complex z = new Complex(c);
        int count = 1;

        for (; z.sizeSquared() < 4.0 && count < lim; count++)
        {
            z.multiply(z);
            z.add(c);
        }
        return count;
    }
    public void show(Applet a, Graphics g, int x, int y)
    {
        int count, b, colr,
            lim = (int) Math.pow(2,clr);
        int[] p = new int[res*res],
              colors = new int[24];

        for (int i = 0; i < 24; i++)
            colors[i] = 1 << i;

        for (int row = 0; row < res; row++)
        for (int col = 0; col < res; col++)
        {
            // Encode the count as a pixel
            p[res*row + col] = 255 << 24;
            if (cnt[row][col] != lim)
            {
                count = cnt[row][col];
                for (b = 0; b < 3; b++)
                for (int c = 0; c < clr; c++)
                {
                    colr = ((count & 1) == 1) ? colors[8-clr + b*8 + c] : 0;
                    p[res*row + col] = p[res*row + col] | colr;
                    count = count >> 1;
                }
            }
        }
        // create, display image
        MemoryImageSource m = new MemoryImageSource(res, res, p, 0, res);
        Image imag = a.createImage(m);
        g.drawImage(imag, x, y, null);
    }
}