head	1.1;
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comment	@# @;


1.1
date	97.12.01.03.59.30;	author hans;	state Exp;
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desc
@animation of chaotic behavior
the panel which shows the movement of the pendulum
@


1.1
log
@Initial revision
@
text
@import java.awt.*;
import java.util.*;
import java.lang.*;


//
// object to draw the pendulum
//
 
class graphic extends Panel
{
   Graphics g;
   Dimension d;
   int xo, yo, x0, y0;
   double tx=0.0;
   double ty=0.0;
   Image offscreen;
  
   
   graphic()
   {
     
     setBackground(Color.lightGray);
   }
   
   
   public void exit()
   {
      if (offscreen != null)
      {
         offscreen.flush();
      }
   }
   public void draw(double x, double v)
   {
      
      if (offscreen==null)
      {
         d=size();
         offscreen=this.createImage(d.width, d.height);
      }
      g = offscreen.getGraphics();
      d = size();
      
      x0=(int)(d.width/2)+15;
      y0=(int)(d.height/2);
      xo=(int) ((d.width/4)*Math.sin(x));
      yo=(int) ((d.width/4)*Math.cos(x));
      g.setColor(Color.lightGray);
      g.fillRect(0,0,d.width, d.height);    
      g.setColor(Color.red);
      g.drawLine (x0,y0,x0+xo,y0+yo);
      float color=(float) (Math.abs(v)/2);
      if(color>1.0) color=(float) 1.0;
      g.setColor(new Color(color,color,(float) 1.0));
      g.fillOval(xo+x0-5,yo+y0-5,10,10);
      
      g = this.getGraphics();
      if(g!=null)
      {
         g.drawImage(offscreen, 0, 0, Color.lightGray, this);
      }
   }
   public void drawint(double x , double y)
   {
      tx = x;
      ty = y;
   }
   public void paint(Graphics g)
   {
      if(offscreen!=null)
      {
         g.drawImage(offscreen, 0, 0, Color.lightGray, this);
      }
      else
      {
         d= size();
         offscreen=this.createImage(d.width, d.height);
         draw(tx, ty);
      }
   }
}


 
@