/*&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
| YLL 4/11/2004
| Modified for Eliashberg ....
| 
| Basic framework for eliashulation.
| Class inheritance hierarchy:
|     eliash extends Applet
|     eliashCanvas extends Canvas
|     eliashFrame extends Frame
| Member hierarchy:
|     eliashFrame sf
|     |--- Applet applet
|          |--- eliashFrame sf (circular reference)
|     |--- GridBagConstraints gbc (data structure)
|     |--- eliashCanvas cv (placed LHS)
|     |--- Panel panelControl (placed RHS)
|          |--- List listPreset
|          |--- Choice choiceMode
|          |--- ...
| Coordinate systems:
|     xmax=wxbor+xdisp+wxbor  (eliashulate xmax*ymax cells, display xdisp*ydisp)
|     

use 50 and 0.03 for mags

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*/
/*
<applet code=eliash.class width=10 height=10>
Sorry, you need a Java-enabled browser to see the eliashulation.
</applet>
*/
    // some graphics ssettings
    // Note: coordinate scing:
    // [x]   [xs 0  xo] [wx]
    // [y] = [0  ys yo] [wy]
    // [1]   [0  0  1 ] [1 ]




import java.awt.*;
import java.applet.Applet;
//import java.lang.Math;
import java.awt.event.*;
import java.util.Random; // for clas RAndom

public class eliash extends Applet {
  //----- Override Applet methods -----
  eliashFrame sf;
  public void init() {sf = new eliashFrame(this);	sf.init(); }
  public void destroy() {if (sf != null) sf.dispose(); sf = null;   }
};

class eliashCanvas extends Canvas {
  eliashFrame sf;
  eliashCanvas(eliashFrame sf0) {sf = sf0;}
  //  public Dimension getPreferredSize() {return new Dimension(300,400);}
  //  public Dimension getMinimumSize() {return new Dimension(16,16);}
  // doesn't help
  public void update(Graphics g) {sf.updateeliash(g);}
  public void paint(Graphics g) {sf.updateeliash(g);}
};

class eliashFrame extends Frame
  implements ComponentListener, ActionListener, AdjustmentListener,
	     //             MouseMotionListener,
	     MouseListener, ItemListener, WindowListener {

  //----- Objects -----
  static long timeNow,timeLast,timeElapsed;
  static int framesElapsed=0;
  float fps;
  Random random;
  Dimension dimWin;
  int winwidth,winheight;
  Image imOffscreen;
  ScrollPane spControl;
  Panel panelControl;
  Button buttonClear;
  Checkbox cbRunning;
  Choice choiceMode;
  Label labelSpeed;
  Label labelRes;
  Label labelFPS;
  List listPreset;
  Scrollbar sbDamping;
  Scrollbar sbSpeed;
  Scrollbar sbRes;
  Scrollbar sbBri;
  eliashCanvas cv;
  eliash applet;
  TextField tfxmax;
  TextField tfymax;
  TextField tfTem;
  TextField tfgnu;

  static final float pi = (float)Math.PI;
  static final float twopi = (float)(2*Math.PI);
  static final float ootwopi = (float)(1/(2*Math.PI));
  float xmin,ymin,xmax,ymax;
  int wxmin,wymin,wxmax,wymax;
  int xorg,yorg;
  float xsc,ysc;
  float magD,magF,magV;
  float t;
  int pause;
  int nmax;
  float dd[];
  float ff[];
  float ddnew[];
  float tem;//=0.01f; // temperature T
  float gnu;

  //----- Constructor -----
  eliashFrame(eliash applet0) {super("eliash"); applet = applet0; }

  //----- init(), reinit() are actually user-defined ----
  public void init() {
    random = new Random();
    timeNow = System.currentTimeMillis();
    timeLast = System.currentTimeMillis();

    t = 0.0f;

    this.addWindowListener(this);

    cv = new eliashCanvas(this);
    cv.addComponentListener(this);
    cv.addMouseListener(this);
    //cv.addMouseMotionListener(this);
    this.add(cv, BorderLayout.CENTER);

    spControl = new ScrollPane();
    this.add(spControl, BorderLayout.LINE_END);

    panelControl = new Panel();
    panelControl.setLayout(new GridBagLayout());
    GridBagConstraints gbc = new GridBagConstraints();
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.fill = GridBagConstraints.HORIZONTAL;
    gbc.insets = new Insets (0, 8, 0, 8);  // S,W,N,E

    spControl.add(panelControl);
    spControl.setSize (160, 800); // can't help it

    listPreset = new List(4, false);
    listPreset.add("Clear");
    listPreset.add("Vortex pair");
    listPreset.add("Pluto");
    //listPreset.addItemListener(this); don't listen to item events from list
    listPreset.addActionListener(this);
    panelControl.add(listPreset, gbc);

    choiceMode = new Choice();
    choiceMode.add("Choice");
    choiceMode.add("Choice 2");
    choiceMode.addItemListener(this);
    panelControl.add(choiceMode, gbc);
    
    buttonClear = new Button("Button");
    panelControl.add(buttonClear, gbc);
    buttonClear.addActionListener(this);

    cbRunning = new Checkbox("Running", true);
    cbRunning.addItemListener(this);
    panelControl.add(cbRunning, gbc);

    panelControl.add(labelSpeed = new Label("eliashulation Speed", Label.CENTER), gbc);
    panelControl.add(sbSpeed = new Scrollbar(Scrollbar.HORIZONTAL, 1, 1, 1, 100), gbc);
    sbSpeed.addAdjustmentListener(this);

    gbc.gridwidth = GridBagConstraints.RELATIVE;
    panelControl.add(new Label("xmax"), gbc);
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    panelControl.add(tfxmax = new TextField("1"), gbc);
    tfxmax.addActionListener(this);

    gbc.gridwidth = GridBagConstraints.RELATIVE;
    panelControl.add(new Label("ymax"), gbc);
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    panelControl.add(tfymax = new TextField("0.1"), gbc);
    tfymax.addActionListener(this);

    gbc.gridwidth = GridBagConstraints.RELATIVE;
    panelControl.add(new Label("g*nu"), gbc);
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    panelControl.add(tfgnu = new TextField("0.4"), gbc);
    tfgnu.addActionListener(this);

    gbc.gridwidth = GridBagConstraints.RELATIVE;
    panelControl.add(new Label("T"), gbc);
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    panelControl.add(tfTem = new TextField("0.001"), gbc);
    tfTem.addActionListener(this);

    /*
    labelFPS = new Label("FPS");
    panelControl.add(labelFPS, gbc);
    */

    //somepa arams
    setParams();
    magD = 1f;
    magV = 0.01f;

    nmax = 512;
    pause = 10;
    reinit();
    //    cv.setBackground(Color.gray);
    
    setSize(800, 800);
    handleResize();
    show();

  }

  void reinit() {
    dd = new float[nmax];
    ff = new float[nmax];
    ddnew = new float[nmax];
    int n;
    for (n=0; n<nmax; n++) {
      dd[n] = 1.0f;
      ff[n] = 0;
    }
  }

  //----- Override paint -----
  public void paint(Graphics g) {cv.repaint();}

  //----- Implement ComponentListener -----
  public void componentHidden(ComponentEvent e){}
  public void componentMoved(ComponentEvent e){}
  public void componentShown(ComponentEvent e) {cv.repaint();  }
  public void componentResized(ComponentEvent e) {handleResize(); cv.repaint(100);}
  //----- Implement ActionListener -----
  public void actionPerformed(ActionEvent e) {
    if (e.getSource() == buttonClear) {
      cv.repaint();
    }
    else if (      // probabky should put the foloiwng in sep func
	     e.getSource()==tfxmax ||
	     e.getSource()==tfymax ||
	     e.getSource()==tfTem ||
	     e.getSource()==tfgnu
	     ) {
      setParams();
    }
    else if (e.getSource() == listPreset) { 
      int i;
      i = listPreset.getSelectedIndex(); // not strictly correct,b ut works
      System.out.println("selected preset "+i);
      switch (i) {
      case 0: // Clear
	break;
      default: ;
      }
    }
  }

  
  //----- Implement ItemListener -----
  public void itemStateChanged(ItemEvent e) {
    if (e.getItemSelectable() == cbRunning) cv.repaint();
    //    else if (e.getItemSelectable() == listPreset) { }
  }
  //----- Implement MouseListener -----
  public void mouseClicked(MouseEvent e) {
    int wx=e.getX();
    int wy=e.getY();    
    int x,y;
    //x = wx*xdisp/wxmax + wxbor; inversetrans
    //y = wy*ydisp/wymax + wybor;
  }
  public void mousePressed(MouseEvent e) {}
  public void mouseReleased(MouseEvent e) {} 
  public void mouseEntered(MouseEvent e) {}
  public void mouseExited(MouseEvent e) {}
  //----- Implement MouseMotionListener -----
  //  public void mouseDragged(MouseEvent e) {}
  //  public void mouseMoved(MouseEvent e) {}

  //----- Implement WindowListener -----
  public void windowClosing(WindowEvent e) {dispose();}
  public void windowOpened(WindowEvent e) {}
  public void windowIconified(WindowEvent e) {}
  public void windowDeiconified(WindowEvent e) {}
  public void windowClosed(WindowEvent e) {}
  public void windowActivated(WindowEvent e) {}
  public void windowDeactivated(WindowEvent e) {}


  //----- Implement AdjustmentListener -----
  public void adjustmentValueChanged(AdjustmentEvent e) {
    System.out.print(((Scrollbar) e.getSource()).getValue() + "\n");
    if (e.getSource() == sbSpeed) {
      labelSpeed.setText ("Speed: "+sbSpeed.getValue());
    }
  }

  //----- User-defined methods -----
  // setParams() gets value from text fields (and sliders)? and puts to vars
  // To set Res from applet, use {sbRes.setValue(x); setRes();}
  void setParams() {
    xmax = Float.parseFloat (tfxmax.getText());
    ymax = Float.parseFloat (tfymax.getText());
    tem = Float.parseFloat (tfTem.getText());
    gnu = Float.parseFloat (tfgnu.getText());
    int n;
    for (n=0; n<nmax; n++) dd[n] += ((float)Math.random()) * 1e-10; // kick
    cbRunning.setState(true); cv.repaint(); //restart sim
  }

  void handleResize() {
    // It's a pity we couldn't use setMinimumSize(new Dimension(0,0)) on "cv",
    // because Canvas is not a subclass of Component.
    dimWin = cv.getSize(); winwidth = dimWin.width; winheight = dimWin.height;
    if (winwidth<=0 || winheight<=0) return;
    imOffscreen = createImage(winwidth, winheight);
  }

  //----- compute alpha squared F
  final float funcV (float wn) {
    float wd = 0.1f;
    float x = wn/wd;  // wdebye=0.1, say
    return twopi*gnu/(1+x*x);  // Lorentzian.  I'm assuming that 2*pi*nu=1.
    // Therefore, g=gnu/nu = gnu*2*pi.
  }

  public void updateeliash(Graphics realg) {
    // this works around some weird bug in IE which causes the
    // applet to not show up properly sometimes.
    if (dimWin == null || winwidth == 0) {handleResize(); return;}
    Graphics g = imOffscreen.getGraphics();
    boolean boolRunning = cbRunning.getState();
    int iterCount = sbSpeed.getValue();
    //    double mult = sbBri.getValue() / 5.0;


    //----- Recalc and re-prepare offscreen image -----
    if (boolRunning) {

      //----- Timing routines ----
      /*
      timeNow = System.currentTimeMillis();
      timeElapsed = timeNow - timeLast;
      framesElapsed++;
      //    System.out.println (timeElapsed);
      if (timeElapsed >= 1000) {
	fps = framesElapsed*1000.0f/timeElapsed;
	//labelFPS.setText (timeElapsed+"ms"); 
	labelFPS.setText ("FPS: "+(int)fps + "; IPS: " +(int)(fps*iterCount));
	timeLast = timeNow;
	framesElapsed = 0;
      }
      */
  
      //----- Eliashberg equations -----
      // let 2*pi*nu=1
      float x,y,w,e,tpt,d;
      int m,n,X,Y,X2,Y2;

      tpt = twopi*tem;

      // For some reason, applet becomes unresponsive if updateeliash finishes too quickly
      // (bizarre!) Therefore set speed high. ...?
      for (int iter=0; iter<iterCount; iter++) {
	// calculate F (easy)
	for (n=0; n<nmax; n++) {
	  e = tpt*(n+0.5f);
	  d = dd[n];
	  ff[n] = (float)( 0.5f*d/Math.sqrt(e*e + d*d) );
	}

	// calculate D (convolution)
	for (m=0; m<nmax; m++) {
	  ddnew[m] = 0;
	  for (n=0; n<nmax; n++) {
	    ddnew[m] += tem * ( funcV(tpt*(m-n)) + funcV(tpt*(m+n+1))  ) * ff[n];
	  }
	}
	// overrelax
	for (n=0; n<nmax; n++) {
	  ddnew[n] += (ddnew[n] - dd[n])*0.8f;
	}


	// Automatic stopping
	float lastchange,dum;
	lastchange = 0;
	for (n=0; n<nmax; n++) {
	  dum = ddnew[n] - dd[n];
	  lastchange += dum*dum;
	}
	//System.out.println(lastchange);
	if (lastchange < 1e-32) {
	  boolRunning=false; cbRunning.setState(false);
	}



	// update D
	for (n=0; n<nmax; n++) {
	  dd[n] = ddnew[n];
	}

      }
    
      //----- Update the offscreen image -----
      int wxbor,wybor;
      int rad=2;   

      g.setColor(cv.getBackground());
      g.fillRect(0, 0, winwidth, winheight);  // takes a long time

      //----- DEFINE AUX COORD SYS VARIABLES e.g. xorg,xsc
      // want  xo = xo + xs * 0,  wxmax-wxbor = xo + xs * xmax, ...
      // so xs = (wxmax-wxbor-xo)/xmax, etc.
      // well, actually 
      //  wxmin = xo + xs * xmin
      //  wxmax = xo + xs * xmax
      // so xs = (wxmax-wxmin)/(xmax-xmin), xo=wxmin - xs*xmin
      wxbor = wybor = 16;
      wxmin = wxbor; wxmax = winwidth - wxbor;
      wymax = wybor; wymin = winheight - wybor; // NOTE SWAP

      xmin = -xmax/10f;
      ymin = -ymax/10f;
      xsc = (wxmax-wxmin)/(xmax-xmin); xorg = wxmin - (int)(xsc*xmin);
      ysc = (wymax-wymin)/(ymax-ymin); yorg = wymin - (int)(ysc*ymin);

      g.setColor (Color.black);
      g.drawLine (xorg, wymin, xorg, wymax);
      g.drawLine (wxmin, yorg, wxmax, yorg);
      int ntick;
      for (ntick=0; ntick<=10; ntick++) {
	x = xmax*ntick/10f;
	X = xorg + (int)(xsc*x);
	g.drawLine (X, yorg-5, X, yorg+5);
      }
      for (ntick=-10; ntick<=10; ntick++) {
	y = ymax*ntick/10f;
	Y = yorg + (int)(ysc*y);
	g.drawLine (xorg-5, Y, xorg+5, Y);
      }
      g.drawString (Float.toString(xmax), wxmax-16, yorg+32);
      g.drawString (Float.toString(ymax), xorg+10, wymax+8);
     

      // Delta
      g.setColor (Color.blue);
      X=Y=0;
      for (n=0; n<nmax; n++) {
	x = tpt*(n+0.5f);
	y = dd[n]*magD;
	X2 = xorg + (int)(xsc*x);
	Y2 = yorg + (int)(ysc*y);
	g.fillOval (X2-rad, Y2-rad, rad+rad, rad+rad);
	if (n>0) g.drawLine (X, Y, X2, Y2);
	X = X2;
	Y = Y2;
      }

      // V
      g.setColor (Color.red);
      X=Y=0;
      for (n=0; n<nmax; n++) {
	x = tpt*n;
	y = funcV(x)*magV;
	X2 = xorg + (int)(xsc*x);
	Y2 = yorg + (int)(ysc*y);
	g.fillOval (X2-rad, Y2-rad, rad+rad, rad+rad);
	if (n>0) g.drawLine (X, Y, X2, Y2);
	X = X2;
	Y = Y2;
      }

      t++;
    }
    //----- Put offscreen image to screen even if sim is paused -----
    realg.drawImage(imOffscreen, 0, 0, this);
    //----- Trigger the next update within <pause> ms (pause a bit redundant ...) -----
    if (boolRunning) {
      cv.repaint(pause);
    }
  }

}