/* Filled Julia set    Evgeny Demidov,  1 October 2000
   URL: www.ipm.sci-nnov.ru/~demidov/eng/java_e.htm */

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

public class @file extends java.applet.Applet implements MouseListener {
double maxIZI2=4., Ymid=.0, Xmid=-.5, DelX=3.,  paramC,paramD, eps, Rorb,Iorb;
int MaxIt = 256,  maxColor = 96, w, h, pixArr[];
Image img;             IndexColorModel RainbowColor;
long generTime;        boolean   showXY = true;
FormulaFJ formBT;        TextField tfXY;

public void init() {
  String s=getParameter("XYmidDelCD"); 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();
    paramC = Double.valueOf(st.nextToken()).doubleValue();
    paramD = 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);
  int M=maxColor/3,  M2=2*M;  maxColor = 3*M;     // maxColor is 3*int
  long M4 = (long)M*M*M*M;
  byte rColor[] = new byte[maxColor+1], bColor[] = new byte[maxColor+1],
       gColor[] = new byte[maxColor+1];
  for (int i = 1; i < M2; i++){                   // set Color Map
    long dum = M - i;  dum *=dum;  dum *=dum;
    gColor[i] =  bColor[(i+M) % maxColor] = rColor[(i+M2) % maxColor] =
        (byte)(255 - (255*dum)/M4);}
  RainbowColor = new IndexColorModel( 8, maxColor+1, rColor,gColor,bColor);
  w = getSize().width;   h = getSize().height;
  s=getParameter("showXY");
  if ( (s != null) && (s.equalsIgnoreCase("N")) ) showXY = true;
  else{
    setLayout(new BorderLayout());
    if (Ymid < 0.) s = ""+Xmid+" "+Ymid+"*i; "+(float)DelX;
       else s = ""+Xmid+" +"+Ymid+"*i; "+(float)DelX;
    tfXY = new TextField( s );
    add("South",  tfXY);
    h -= tfXY.getPreferredSize().height;}
  pixArr = new int[w*(h+2)];
  s=getParameter("Formula");
  if (s != null)
    try{  formBT = (FormulaFJ)Class.forName( s ).newInstance();
    }catch(Exception e){}
  else    formBT = new FilledJulZ2();
  formBT.set(3*MaxIt, maxColor, maxIZI2, 0, 10., 10.);
  formBT.iterate(0., 0., paramC, paramD);
  Rorb = formBT.lastR;    Iorb = formBT.lastI;
  formBT.set(MaxIt, maxColor, maxIZI2, 1e-6, Rorb, Iorb);
  formBT.iterate(0., 0., paramC, paramD);
  double tr = Rorb - formBT.lastR,   ti = Iorb - formBT.lastI;
  eps =tr*tr + ti*ti;
  formBT.set(MaxIt, maxColor, maxIZI2, eps, Rorb, Iorb);
  generTime = System.currentTimeMillis();
  Direct(Xmid, Ymid, DelX/w, formBT, paramC, paramD );
  img = createImage(new MemoryImageSource(w, h, RainbowColor, pixArr, w, w));
  generTime = System.currentTimeMillis()-generTime;
  addMouseListener(this);
}

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()-w/2)*DelX/w;
  Ymid = Ymid-(e.getY()-h/2)*DelX/w;
  if ( e.isControlDown() ) {
    if ( e.isShiftDown() )  DelX *=4.;  else  DelX *=2.;}
  else {
    if ( e.isShiftDown() )  DelX /=4.;  else  DelX /=2.;}
  generTime = System.currentTimeMillis();
  Direct(Xmid, Ymid, DelX/w, formBT, paramC, paramD);
  img.flush();
  img = createImage(new MemoryImageSource(w, h, RainbowColor, pixArr, w, w));
  generTime = System.currentTimeMillis()-generTime;
  if (showXY) {
    if (Ymid < 0.) tfXY.setText( ""+Xmid+" "+Ymid+"*i; "+(float)DelX);
       else  tfXY.setText( ""+Xmid+" +"+Ymid+"*i; "+(float)DelX);};
  repaint();
}

public void paint(Graphics g) {
  g.drawImage(img, 0, 0, this);
  drawLabel(g);
  showStatus( "Time=" + generTime + " msec");
}

public void drawLabel(Graphics gra) {
 double  R=0.,I=0., StZ=DelX/w;
 gra.setColor(Color.white);
 int ix,iy;
 String s=getParameter("sqrRID"); if (s != null) {
   StringTokenizer st = new StringTokenizer(s);
   double sqrRmid = Double.valueOf(st.nextToken()).doubleValue(),
   sqrImid = Double.valueOf(st.nextToken()).doubleValue();
   int sqr = (int)(Double.valueOf(st.nextToken()).doubleValue()/StZ);
   ix = (w - sqr)/2 + (int)((sqrRmid-Xmid)/StZ);
   iy = (h - sqr)/2 + (int)((Ymid - sqrImid) /StZ);
   gra.drawRect(ix,iy, sqr,sqr);}
 gra.setFont(
   new Font( gra.getFont().getName(), Font.BOLD, 15 ) );
 int maxLabel=0, w2 = w/2, h2 = h/2;
 double dw2 = w2, dh2 = h2;
 while (true) {
   s=getParameter("lb"+maxLabel);
   if (s == null) break;
   StringTokenizer st = new StringTokenizer(s);
   double x=(Double.valueOf(st.nextToken()).doubleValue()-Xmid)/StZ,
   y=(Ymid-Double.valueOf(st.nextToken()).doubleValue())/StZ;
   if ( (Math.abs(x)<dw2)&&(Math.abs(y)<dh2) ){
     ix = w2+(int)x;  iy = h2+(int)y;
     gra.drawString(st.nextToken(), ix,iy);}
   maxLabel++; }
}

public void Direct( double Xmid, double Ymid, double Step,
  FormulaFJ form, double parC, double parD){
  double X,Y;
  int pix=w, ix,iy;
  for (iy=0, Y=Ymid+Step*h/2; iy < h; iy++, Y-=Step) {
   for (ix=0, X=Xmid-Step*(w/2-1); ix < w; ix++, X+=Step, pix++) {
      pixArr[pix] =form.iterate(X, Y, parC, parD);
   }
  }
}

}

abstract class FormulaFJ{
  int MaxIt, maxColor;
  double maxIZI2, eps,  Rorb, Iorb,  lastR, lastI;
  void set(int mIt, int mCol, double mIZI2, double e, double Ro, double Io) {
    MaxIt = mIt;   maxColor = mCol;  maxIZI2 = mIZI2;  eps = e;
    Rorb = Ro;    Iorb = Io;
  }
  abstract int iterate(double x, double y, double paramC, double paramD);
}

class FilledJulZ2 extends FormulaFJ {
  int iterate(double re, double im, double Cr, double Ci) {
    double I=im, R=re,  I2=I*I, R2=R*R;   int n=0;
    do  {  I=(R+R)*I+Ci;  R=R2-I2+Cr;  R2=R*R;  I2=I*I;  n++;
      if (R2+I2 > maxIZI2) return n % maxColor;
    } while (((R-Rorb)*(R-Rorb)+(I-Iorb)*(I-Iorb) > eps) && (n < MaxIt) );
    lastR = R;  lastI = I;
    if (n == MaxIt) return maxColor;  else return n % maxColor;
  }
}

class FilledJulZ2black extends FormulaFJ {
  int iterate(double re, double im, double Cr, double Ci) {
    double I=im, R=re,  I2=I*I, R2=R*R;   int n=0;
    do  {  I=(R+R)*I+Ci;  R=R2-I2+Cr;  R2=R*R;  I2=I*I;  n++;
      if (R2+I2 > maxIZI2) return maxColor;
    } while (((R-Rorb)*(R-Rorb)+(I-Iorb)*(I-Iorb) > eps) && (n < MaxIt) );
    lastR = R;  lastI = I;
    if (n == MaxIt) return maxColor;  else return n % maxColor;
  }
}

class HenonInt extends FormulaFJ{
 int iterate(double Xo, double Yo, double a, double b){
    double X=a + Xo*Xo + b*Yo, X2=X*X, X1, Y=Xo;   int n=0;
    do{
      X1 = a + X2 + b*Y;  Y = X;
      X = X1;  X2 = X*X;   n++;
      if (X2 > 1000.) return n % maxColor;
    } while (((X-Rorb)*(X-Rorb)+(Y-Iorb)*(Y-Iorb) > eps) && (n < MaxIt) );
    lastR = X;  lastI = Y;
    if (n == MaxIt) return maxColor;  else return n % maxColor;
 }
}