/**	Copyright 2002 Henry Bottomley (henry.bottomley@btinternet.com)
 *	Published for information and comment purposes
 */

import java.awt.*;
import java.awt.image.*;
import java.applet.*;
import java.lang.*;

public class Halfarea extends Applet 
{
	protected int x1, x4, x5, y1, y4, y5; 
        protected final static int x2=100; 
        protected final static int x3=400; 
        protected final static int y2=310; 
        protected final static int y3=310; 
				
///////////////////////////////////////////////////////////////////////////
				
	public void init()
		{		
		x1=100; 
		y1=10;
		}				
				
///////////////////////////////////////////////////////////////////////////
				
				
	public void paint (Graphics g)
		{
		g.setColor(Color.white);//blank the applet
		g.fillRect(0, 0, size().width, size().height);

		g.setColor(Color.green);// other area bisectors		
		g.drawLine((x1+x2*9)/10,(y1+y2*9)/10,(x1*4+x3*5)/9,(y1*4+y3*5)/9);
		g.drawLine((x2+x3*9)/10,(y2+y3*9)/10,(x2*4+x1*5)/9,(y2*4+y1*5)/9);
		g.drawLine((x3+x1*9)/10,(y3+y1*9)/10,(x3*4+x2*5)/9,(y3*4+y2*5)/9);
		g.drawLine((x1+x3*9)/10,(y1+y3*9)/10,(x1*4+x2*5)/9,(y1*4+y2*5)/9);
		g.drawLine((x3+x2*9)/10,(y3+y2*9)/10,(x3*4+x1*5)/9,(y3*4+y1*5)/9);
		g.drawLine((x2+x1*9)/10,(y2+y1*9)/10,(x2*4+x3*5)/9,(y2*4+y3*5)/9);
		g.drawLine((x1+x2*4)/5,(y1+y2*4)/5,(x1*3+x3*5)/8,(y1*3+y3*5)/8);
		g.drawLine((x2+x3*4)/5,(y2+y3*4)/5,(x2*3+x1*5)/8,(y2*3+y1*5)/8);
		g.drawLine((x3+x1*4)/5,(y3+y1*4)/5,(x3*3+x2*5)/8,(y3*3+y2*5)/8);
		g.drawLine((x1+x3*4)/5,(y1+y3*4)/5,(x1*3+x2*5)/8,(y1*3+y2*5)/8);
		g.drawLine((x3+x2*4)/5,(y3+y2*4)/5,(x3*3+x1*5)/8,(y3*3+y1*5)/8);
		g.drawLine((x2+x1*4)/5,(y2+y1*4)/5,(x2*3+x3*5)/8,(y2*3+y3*5)/8);
		g.drawLine((x1*2929+x2*7071)/10000,(y1*2929+y2*7071)/10000,(x1*2929+x3*7071)/10000,(y1*2929+y3*7071)/10000);
		g.drawLine((x2*2929+x3*7071)/10000,(y2*2929+y3*7071)/10000,(x2*2929+x1*7071)/10000,(y2*2929+y1*7071)/10000);
		g.drawLine((x3*2929+x1*7071)/10000,(y3*2929+y1*7071)/10000,(x3*2929+x2*7071)/10000,(y3*2929+y2*7071)/10000);

		g.setColor(Color.blue);// medians		
		g.drawLine(x1,y1,(x2+x3)/2,(y2+y3)/2);
		g.drawLine(x2,y2,(x3+x1)/2,(y3+y1)/2);
		g.drawLine(x3,y3,(x1+x2)/2,(y1+y2)/2);

		g.setColor(Color.red);// the deltoid		
		x5=(x1+x2+2*x3)/4;
		y5=(y1+y2+2*y3)/4;
		for (int i=26; i<=50; i++)
			{
			x4=(x2*i*i+1250*x3+(100*i-i*i-1250)*x1)/(100*i);
			y4=(y2*i*i+1250*y3+(100*i-i*i-1250)*y1)/(100*i);
			g.drawLine(x4,y4,x5,y5);
			x5=x4;
			y5=y4;			
			} 
		x5=(x2+x3+2*x1)/4;
		y5=(y2+y3+2*y1)/4;
		for (int i=26; i<=50; i++)
			{
			x4=(x3*i*i+1250*x1+(100*i-i*i-1250)*x2)/(100*i);
			y4=(y3*i*i+1250*y1+(100*i-i*i-1250)*y2)/(100*i);
			g.drawLine(x4,y4,x5,y5);
			x5=x4;
			y5=y4;			
			} 
		x5=(x3+x1+2*x2)/4;
		y5=(y3+y1+2*y2)/4;
		for (int i=26; i<=50; i++)
			{
			x4=(x1*i*i+1250*x2+(100*i-i*i-1250)*x3)/(100*i);
			y4=(y1*i*i+1250*y2+(100*i-i*i-1250)*y3)/(100*i);
			g.drawLine(x4,y4,x5,y5);
			x5=x4;
			y5=y4;			
			} 

		g.setColor(Color.black); // edges of the original triangle		
		g.drawLine(x1,y1,x2,y2);
		g.drawLine(x2,y2,x3,y3);
		g.drawLine(x3,y3,x1,y1);

		}

				
///////////////////////////////////////////////////////////////////////////
				
	//taken from comp.lang.java FAQ 
	  private Image offScreenImage;
	  private Dimension offScreenSize;
	  private Graphics offScreenGraphics;
	   
	  public final synchronized void update (Graphics g) 
	    {
	    Dimension d = size();
	    if((offScreenImage == null) || (d.width != offScreenSize.width) ||  (d.height != offScreenSize.height)) 
	      {
	      offScreenImage = createImage(d.width, d.height);
	      offScreenSize = d;
	      offScreenGraphics = offScreenImage.getGraphics();
	      }
	    offScreenGraphics.clearRect(0, 0, d.width, d.height);
	    paint(offScreenGraphics);
	    g.drawImage(offScreenImage, 0, 0, null);
	    }
	    
				
///////////////////////////////////////////////////////////////////////////
				
	public boolean mouseDown (Event evt, int x, int y) // identify point chosen for start
		{
		x1 = x;
                y1 = y;
		repaint();	
		return true;
		}
				
///////////////////////////////////////////////////////////////////////////
				
	public boolean mouseDrag (Event evt, int x, int y) 
		{
		x1 = x;
                y1 = y;
		repaint();	
		return true;
		}
				
///////////////////////////////////////////////////////////////////////////
				
	} // end of class