// Colored bifurcations map,  Evgeny Demidov,  18 Nov 2005

import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import java.util.StringTokenizer;

public class @file extends java.applet.Applet implements MouseListener {
Image img;              IndexColorModel iColor;
int MaxIt = 256, w,h, w2,wh, pixArr[],  maxColor = 20;
double maxIZI2=4., Ymid=.0, Xmid=-.5, DelX=3., Ratio=1,  Xm, Ym;
boolean   showXY = false;
TextField tfXY;

public void init() {
  w = getSize().width;    h = getSize().height;
  w2 = w/2;  wh = w*h;
  pixArr = new int[wh];
  String s=getParameter("XYmidDelC"); if (s != null) {
    StringTokenizer st = new StringTokenizer(s);
    Xmid = Double.valueOf(st.nextToken()).doubleValue();
    Ymid = Double.valueOf(st.nextToken()).doubleValue();
    DelX = Double.valueOf(st.nextToken()).doubleValue();
    Ratio = Double.valueOf(st.nextToken()).doubleValue();}
  s=getParameter("MaxIt"); if (s != null) MaxIt=Integer.parseInt(s);
  s=getParameter("MaxColor"); if (s != null) maxColor=Integer.parseInt(s);
  byte rColor[] = new byte[maxColor+2], bColor[] = new byte[maxColor+2],
       gColor[] = new byte[maxColor+2];
  int M=maxColor/2;
  long M4 = (long)M*M*M*M;
  for (int i = 0; i < M; i++){
    long dum = i;  dum *=dum;  dum *=dum;
    bColor[i] = gColor[M+i] = gColor[M-i] = rColor[maxColor-1-i] =
     (byte)(255 - (255*dum)/M4);}
  rColor[0] = gColor[0] = bColor[0] = (byte)255;
  iColor = new IndexColorModel( 8, maxColor+2, rColor,gColor,bColor);
  s=getParameter("showXY");
  if ( (s != null) && (s.equalsIgnoreCase("Y")) ) {
    showXY = true;
    setLayout(new BorderLayout());
    s = ""+Xmid+", "+Ymid+"; "+(float)DelX+", "+(float)(DelX/Ratio);
    tfXY = new TextField( s );
    add("South",  tfXY);
    h -= tfXY.getPreferredSize().height;}
  addMouseListener(this);
  draw();
}

public void destroy() {  removeMouseListener(this); }
public void mouseClicked(MouseEvent e) {}      //1.1 event handling
public void mousePressed(MouseEvent e) {}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent  e) {}

public void mouseReleased(MouseEvent e) {
  Xmid = Xmid+(e.getX()-w2)*DelX/w;
  Ymid = Ymid-(e.getY()-h/2)*DelX/(w*Ratio);
  if ( e.isControlDown() ) {
    if ( e.isShiftDown() )  Ratio /= 2.;
    else DelX *= 2.;}
  else {
    if ( e.isShiftDown() )  Ratio *= 2.;
    else DelX /= 2.;}
  if (showXY) tfXY.setText( ""+Xmid+", "+Ymid+"; "+
    (float)DelX +", "+(float)(DelX/Ratio));
  draw();
  repaint();
}

public void draw() {
  int iy,i, maxPix=0, norm;
  double Xo,C, StX=DelX/w, StY=StX/Ratio;
  for (i=0; i < wh; i++) pixArr[i] = 0;
  for (iy=0, C=Ymid+StY*h/2; iy < h; iy++, C-=StY) {
      double X=.5;   int n=0, offset = w*iy;
      do  {
        int nX = (int)((X - Xmid)/StX) + w2;
        if ( (nX >= 0) && (nX < w)) pixArr[nX + offset] += 1;
        X=C*X*(1-X);  n++;
      } while (n < MaxIt);
  }
  int mCol = maxColor-1;
  for (i=0; i < wh; i++) if (pixArr[i] > mCol) pixArr[i] = mCol;
  img = createImage(new MemoryImageSource(w, h, iColor, pixArr, 0, w));
}

public void paint(Graphics g) {
  g.drawImage(img, 0, 0, this);
  showStatus( "X=" + (float)Xmid + "  C=" + (float)Ymid +
    "  dX=" + (float)DelX );
}

}