/*
   THIS IS A VERY SIMPLE JAVA APPLET THAT JUST DRAWS AN X SHAPE.
*/

import java.awt.*;

public class Thread extends BufferedApplet
{
   float X[] = new float[100];
   float Y[] = new float[100];
   float OldX[] = new float[100];
   float OldY[] = new float[100];
   float temp;
   float deltalength;
   float diff;
   float deltax;
   float deltay;
   int balls=15;
   boolean restart = true;
   int heldflag = 0;
   
       
   public void render(Graphics g)
   {

        if (restart == true)
        {
            for (int k=1; k<balls; k++)
            {
                X[k]=15*k;
                Y[k]=0;
                OldX[k]=16*k;
                OldY[k]=0;
            }
            restart = false;
        }
        clearScreen(g);
        placeBalls(g);
        g.setColor(Color.black);
        for (int i=0;i<balls-1;i++)
        {
            g.drawLine((int)X[i],(int)Y[i], (int)X[i+1],(int)Y[i+1]); 
        }
        
   }

   void clearScreen(Graphics g) 
   {
      g.setColor(Color.white);
      g.fillRect(0, 0, bounds().width, bounds().height);
    }

   void placeBalls(Graphics g) 
   {
       for (int k=heldflag; k<balls; k++)
       {
  	  temp=X[k];
          X[k]+=X[k]-OldX[k];
          OldX[k]=temp;
          temp=Y[k];
          Y[k]+=Y[k]-OldY[k];
          OldY[k]=temp;
          Y[k]+=0.2;
          for (int l=0; l<balls-1;l++)
          {
          	deltax=X[l+1]-X[l];
          	deltay=Y[l+1]-Y[l];
          	deltalength=(float)Math.sqrt((double)(deltax*deltax+deltay*deltay));
          	diff=(deltalength-10)/deltalength;
          	X[l]+=deltax*.4*diff;
          	X[l+1]-=deltax*.4*diff;
          	Y[l]+=deltay*.4*diff;
          	Y[l+1]-=deltay*.4*diff;
          }
          if (Y[k] > bounds().height-10) 
          {
              Y[k]=bounds().height-10;
          }
      
        }
   }

   public boolean keyUp(Event e, int key) 
   {
      switch (key) 
      {
      	case ' ':
      	break;
      }
      return true;
   }

   public boolean mouseDown(Event e, int x, int y) 
   {
     // heldflag=1;
      for( int h=0;h<balls-1;h++)
	   {
      		OldX[h] = x;
     		OldY[h] = y;
    		X[h] = x;
   	   	Y[h] = y; 
   	   };
      return true;
   }

   public boolean mouseDrag(Event e, int x, int y) 
   {
      addPoint(x,y);
      return true;
   }

   public boolean mouseUp(Event e, int x, int y) 
   {
    // heldflag=0;
     return true;
   }

   void addPoint(int x, int y) 
   {
   	for( int h=0;h<5;h++)
	   {
      		OldX[h] = x;
     		OldY[h] = y;
    		X[h] = x;
   	   	Y[h] = y; 
   	   }
   }
}