/*********************************/
/*			   	 */
/*    マンデルブロ集合の軌道	 */
/*			    	 */
/*    1998/ 1/19  宍戸　輝光	 */
/*			   	 */
/*********************************/

import java.awt.*;

public class mandd extends java.applet.Applet implements Runnable {

	int max;
	double sr,si,range,dr,di;

	int sn[][]=new int[300][300];

	Image screen;
	Graphics g_screen;

	Color cl[]=new Color[8];

	boolean doing,go;

	Button ctrb;
	Label nl,pl,il;
	TextField rf,imf;
	Thread runner=null;

	public void init(){

		resize(420,360);

		setBackground(Color.lightGray);
		setFont(new Font("TimesRoman",Font.PLAIN,12));

		screen=createImage(302,302); /* 表示用イメージ */
		g_screen=screen.getGraphics();

		this.setLayout((LayoutManager)null);

		ctrb=new Button("Clear");
		add(ctrb);
		ctrb.reshape(316,240,64,32);

		nl=new Label("0 ");
		add(nl);
		nl.reshape(316,288,64,32);

		rf=new TextField(10);
		add(rf);
		rf.reshape(8,316,80,24);
		rf.setBackground(Color.lightGray);

		pl=new Label("+");
		add(pl);
		pl.reshape(90,316,20,20);

		imf=new TextField(10);
		add(imf);
		imf.reshape(112,316,80,24);
		imf.setBackground(Color.lightGray);

		il=new Label("i");
		add(il);
		il.reshape(200,316,16,20);

		cl[0]=new Color(255,255,255);
		cl[1]=new Color(255,192,255);
		cl[2]=new Color(255,128,255);
		cl[3]=new Color(255,128,192);
		cl[4]=new Color(255,128,128);
		cl[5]=new Color(255,0,128);
		cl[6]=new Color(255,0,0);
		cl[7]=new Color(160,0,0);

		max=500;

		clearScreen();
		startDraw();

	}

	public void stop() { /*終了時にスレッド破棄*/

		if (runner!=null) {

			runner.stop();
			runner=null;

		}

	}

	public void clearScreen() {

		g_screen.setColor(Color.black);
		g_screen.fillRect(0,0,300,300);

		sr=-1.5;
		si=-1.0;
		range=2.0;
		dr=range/300.0;
		di=range/300.0;

	}

	public void run() {

		doing=true;
		draw_screen();
		doing=false;

	}

	public void draw_screen() { /* グラフ描画 */

		int i,j,k,n;
		double rlr[]=new double[8];
		double imr[]=new double[8];
		double znr,zni,znr2,zni2,cr,ci;

		dr=range/300.0;
		di=range/300.0;

		for (i=0;i<300;i++)
			for (j=0;j<300;j++)
				sn[j][i]=0;

		for (i=0;i<300;i++) {

			for (j=0;j<300;j++) {

				znr=0; /* 実数部初期値 */
				zni=0; /* 虚数部係数初期値 */

				cr=sr+dr*j; /* Cの実数部 */
				ci=si+di*i; /* Cの虚数部係数 */

				n=1;

				do { /* マンデルブロ集合判定 */

					znr2=(znr*znr)-(zni*zni)+cr;
					zni2=(znr*zni)*2.0+ci;

					znr=znr2;
					zni=zni2;

					if (n>=max-8) {

						rlr[n-(max-8)]=znr;
						imr[n-(max-8)]=zni;

					}

					n++;


				} while (n<max && (znr*znr+zni*zni)<=4);

				if (n==max) {

					for (k=1;k<8;k++)
						if (Math.abs(rlr[7]-rlr[7-k])<1e-10 &&
						 Math.abs(imr[7]-imr[7-k])<1e-10)
							break;

					sn[j][299-i]=k;

					k=k-1;

					g_screen.setColor(cl[k]);

				} else 
					g_screen.setColor(Color.green);

				g_screen.fillRect(j,299-i,1,1);


				if (!go)
					return;

			}

			repaint();

		}

	}

	public boolean action(Event evt,Object what) {

		if (evt.target==ctrb) { /* クリアボタン */

			if (doing) { /* 中断 */

				go=false;
				while (doing);

			}

			clearScreen();
			startDraw();

		}

		return false;

	}

	public void startDraw() {

				go=true;

				runner=new Thread(this);
				runner.start();

	}

	public boolean mouseMove(Event evt,int x,int y) {

		x-=8;
		y-=8;

		if (x<0 ||x>299 ||y<0 ||y>299)
			return false;

		nl.setText(String.valueOf(sn[x][y]));

		rf.setText(String.valueOf(sr+x*dr));
		imf.setText(String.valueOf(si+(299-y)*di));

		return true;

	}

	public boolean mouseDown(Event evt,int x,int y) {

		double wr,wi;

		x-=8;
		y-=8;

		if (x<0 ||x>299 ||y<0 ||y>299)
			return false;

		wr=sr+(range/300.0)*x;
		wi=si+(range/300.0)*(299-y);

		range=range/2.0;
		sr=wr-range/2.0;
		si=wi-range/2.0;

		if (doing) {

			go=false;
			while(doing);

		}

		startDraw();

		return true;

	}

	public void paint(Graphics g){

		g.drawImage(screen,8,8,this);

	}

	public void update(Graphics g){

		paint(g);

	}

}