Mandelbrot.java

import java.lang.Thread;public class Mandelbrot extends Thread {    public Mandelbrot(int width, int height,                       double left, double right,                       double top, double bottom) {        setSize(width, height);        setBoundaries(left, right, top, bottom);        setMaxIterations(10000);    }        public void run() {        while (true) {            if (_recalculate) {                calculate();                _recalculate = false;            }        }    }        public void setBoundaries(double left, double right,                               double top, double bottom) {        // Which bit of the set to view.        _left = left;        _right = right;        _top = top;        _bottom = bottom;        _recalculate = true;    }        public void setSize(int width, int height) {        // Size of our view (zoom).        _width = width;        _height = height;        _set = new int[width][height];        _recalculate = true;    }        public void setMaxIterations(int n) {        _iterations = n;        _recalculate = true;    }        public int getMaxIterations() {        return _iterations;    }        public int value(int x, int y) {        return _set[x][y];    }        private void calculate() {        for (int x = 0; x < _width; x++) {            for (int y = 0; y < _height; y++) {                double zr = 0.0, zi = 0.0;                double cr = _left + x * (_right - _left) / _width;                double ci = _top + y * (_bottom - _top) / _height;                                double zrsq = zr * zr;                double zisq = zi * zi;                                for (_set[x][y] = 0; (zrsq + zisq <= 4.0)                         && (_set[x][y] < _iterations); _set[x][y]++) {                    zr = zrsq - zisq + cr;                    zi = 2 * zr * zi + ci;                    zrsq = zr * zr;                    zisq = zi * zi;                }            }        }    }        private int[][] _set;    private boolean _recalculate;        private double _left;    private double _right;    private double _top;    private double _bottom;    private int _width;    private int _height;    private int _iterations;}