/*

********************************************************************************

** file: Mand.java

** does: Does an exercise of float math and graphics

** author: Bob Jamison, rjamison@gothamcity.jsc.nasa.gov

**

********************************************************************************

*/

import java.awt.*;

import java.applet.Applet;



/*

********************************************************************************

** MAIN CLASS

********************************************************************************

*/

public class Mand extends Applet

{

MandWin mand;



public Mand()

  {

  mand = new MandWin();

  setLayout(new AbsoluteLayout());

  add("North",mand);

  show();

  } 





public static void main(String args[])

  {

  Frame f = new Frame("Mandelbrot Test");

  Mand MandApp = new Mand();

  MandApp.resize(410,450);



  f.resize(420,420);

  f.add("North",MandApp);

  f.show();

  }







}



/*

********************************************************************************

** MANDELBROT PANEL

********************************************************************************

*/

class MandWin extends Panel

{

Label xposlbl,yposlbl;

double range;

double xc,yc;

int xres,yres;



/*

*****

This does the actual Mandelbrot Set calculation at the given x,y coordinate

and return the number of iterations processed.  Done as a separate function

in order to allow it to be used in other ways!

*****

*/

int PointMand(double x,double y,int maxiter)

{

int i;

double a,b;

double a2, b2,twoab,val;

  a = b = 0.0;

  for (i=0;i<maxiter;i++)

    {

    a2  = a*a;

    b2  = b*b;

    val = a2 + b2;

    if (val>=4.0)

      break;

    twoab = 2.0*a*b;

    a = a2 - b2  + x;

    b = twoab + y;

    }

  return i;

}



/*

****

This draws the screen

*****

*/

public void update(Graphics g)

{

double x0,y0,x,y;

double delta;

float xpos,ypos,rng;

int i,row,col,tcol,xoff,yoff,iter,lastiter;

Color clr[];

String pos_lbl;

  xpos = (float)xc;

  ypos = (float)yc;

  rng  = (float)range;

  pos_lbl = "X:"+xpos+"  Y:"+ypos+"   Range:"+rng;

  resize(420,420);

  g.clearRect(0,0,420,420);

  pos_lbl = "X:"+xpos+"  Y:"+ypos;

  g.drawString(pos_lbl,155,350);

  pos_lbl = "Range:"+rng;

  g.drawString(pos_lbl,155,365);

  if (xres<=64)

    xoff = 118;

  else

    xoff = 1;

  if (yres<=64)

    yoff = 158;

  else

    yoff = 0;

  x0 = xc - range/2.0;

  y0 = yc + range/2.0;

  delta = range / (double)yres;

  y=y0;

  iter = 0;

  lastiter = -1;

  clr = new Color[8];

  clr[0] = Color.black;  /*Use "standard" colors*/

  clr[1] = Color.red;

  clr[2] = Color.blue;

  clr[3] = Color.green;

  clr[4] = Color.yellow;

  clr[5] = Color.magenta;

  clr[6] = Color.cyan;

  clr[7] = Color.orange;



  g.setColor(Color.red);

  g.drawRect(xoff-1,yoff-1,xres+2,yres+2);

  g.setColor(clr[0]);

  g.fillRect(xoff,yoff,xres,yres);

  

  for (row=0;row<yres;row++)

    {

    x=x0; tcol=0;

    for (col=0;col<xres;col++)

      {

      iter = PointMand(x,y,63);

      if (iter != lastiter)  /*Color cache*/

        {

        lastiter=iter;

        g.drawLine(tcol+xoff,row+yoff,col+xoff,row+yoff);

        g.setColor(clr[iter&7]);

        tcol=col; /*Color transition cache*/

        }

      x += delta;

      }

    g.setColor(clr[iter&7]);

    g.drawLine(tcol+xoff,row+yoff,col+xoff,row+yoff); /*Finish the line!*/

    y -= delta;

    }



}



/*

****

Do button callbacks

*****

*/

public boolean action(Event evt,Object obj)

  {

  double range2;

  range2 = range / 2.0;

  if (evt.target instanceof Button)

    {

    String label = (String)obj;

    if (label.equals("NW"))

      {

      xc -= range2;

      yc += range2;

      repaint();

      }

    else if (label.equals("N"))

      {

      yc += range2;

      repaint();

      }

    else if (label.equals("NE"))

      {

      xc += range2;

      yc += range2;

      repaint();

      }

    else if (label.equals("W"))

      {

      xc -= range2;

      repaint();

      }

    else if (label.equals("E"))

      {

      xc += range2;

      repaint();

      }

    else if (label.equals("SW"))

      {

      xc -= range2;

      yc -= range2;

      repaint();

      }

    else if (label.equals("S"))

      {

      yc -= range2;

      repaint();

      }

    else if (label.equals("SE"))

      {

      xc += range2;

      yc -= range2;

      repaint();

      }

    else if (label.equals("In"))

      {

      range = range2;

      repaint();

      }

    else if (label.equals("Out"))

      {

      range = range * 2.0;

      repaint();

      }

    else if (label.equals("Big"))

      {

      xres=400; yres=300;

      repaint();

      }

    else if (label.equals("Small"))

      {

      xres=64; yres=64;

      repaint();

      }

      }

  else if (evt.id == Event.WINDOW_DESTROY)

    {

    hide();

    }

  return true;

  }



/*

****

Creates the interface

*****

*/

MandWin()

  {

  Button tmp;



  Panel buttons = new Panel();

  buttons.setLayout(new GridLayout(4,3));



  buttons.add(tmp = new Button("NW"));

  buttons.add(tmp = new Button("N"));

  buttons.add(tmp = new Button("NE"));



  buttons.add(tmp = new Button("W"));

  buttons.add(tmp = new Button("In"));

  buttons.add(tmp = new Button("E"));



  buttons.add(tmp = new Button("SW"));

  buttons.add(tmp = new Button("S"));

  buttons.add(tmp = new Button("SE"));



  buttons.add(tmp = new Button("Small"));

  buttons.add(tmp = new Button("Out"));

  buttons.add(tmp = new Button("Big"));



  resize(420,420);

  /*

  setLayout(new AbsoluteLayout());

  */

  setLayout(null);

  add(buttons);



  buttons.resize(150,110);

  buttons.move(0,310);



  range=0.25;

  xc=0.0;

  yc=0.85;

  xres=64; yres=64;

  }



}



/*

********************************************************************************

** LAYOUT MANAGER

** Note: This class is not mine.  I lost the e-mail where he sent this to me, so I

** can't attribute this,

** but one of the fine engineers at Sun Inc loaned me this nice layout class.

** I'm forever grateful!

********************************************************************************

*/

class AbsoluteLayout implements LayoutManager {



  public AbsoluteLayout()

    {

    }



  public void addLayoutComponent(String name, Component comp)

    {

    }



  public void removeLayoutComponent(Component comp)

    {

    }



  public Dimension preferredLayoutSize(Container parent)

   {

        Insets insets = parent.insets();

        int ncomponents = parent.countComponents();

        int w = 0;

         int h = 0;



        for (int i = 0; i < ncomponents; i++)

         {

            Component comp = parent.getComponent(i);

            Dimension d = comp.preferredSize();

            Point p = comp.location();

            if ((p.x + d.width) > w)

                w = p.x + d.width;

            if ((p.y + d.height) > h)

                h = p.y + d.height;

          }

        return new Dimension(insets.left + insets.right + w,

                             insets.top + insets.bottom + h);

    }



  public Dimension minimumLayoutSize(Container parent)

   {

        Insets insets = parent.insets();

        int ncomponents = parent.countComponents();

        int w = 0;

        int h = 0;



        for (int i = 0; i < ncomponents; i++)

          {

          Component comp = parent.getComponent(i);

          Dimension d = comp.preferredSize();

           Point p = comp.location();

          if ((p.x + d.width) > w)

              w = p.x + d.width;

          if ((p.y + d.height) > h)

              h = p.y + d.height;

          }

        return new Dimension(insets.left + insets.right + w,

                             insets.top + insets.bottom + h);

    }



  public void layoutContainer(Container parent)

   {

    int nmembers = parent.countComponents();



    for (int i = 0; i < nmembers; i++)

     {

     Component m = parent.getComponent(i);

     Dimension d = m.preferredSize();

     m.resize(d.width, d.height);

     }

   }

}

/* END OF FILE ********************************************************************/