/**
 * DistancePanel.java
 *
 * copyright 2004, Daniel Heller
 *
 * latest version may be found at either:
 * http://www.cs.tufts.edu/~dheller/distanceviewer
 * or
 * http://www.dan-is-online.com/software/distanceviewer
 *
 * This program is free software;
 * you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A 
 * PARTICULAR PURPOSE.
 * See the GNU General Public License
 * at http://www.gnu.org/copyleft/gpl.html for more details.
 *
 **/

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;

import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import java.util.Vector;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class DistancePanel extends JPanel
{

   private Vector points = new Vector();
   private int type = 0;
   private int displayType = 0;
   private int threshold = 3;

   public DistancePanel(JFrame viewer)
   {
     addMouseListener(new MouseAdapter(){
       public void mouseClicked(MouseEvent e)
       {
         points.addElement(new Point(e.getX(),e.getY())); 
         repaint();
       }
     });

     viewer.addKeyListener(new KeyAdapter(){
      public void keyPressed(KeyEvent e)
      {
        if(e.getKeyChar()=='1')
        {
          type = 0;
          threshold = 3;
        }
        if(e.getKeyChar()=='2')
        {
          type = 1;
          threshold = 3;
        }
        if(e.getKeyChar()=='3')
        {
          type = 2; 
          threshold = 100;
        }
        if(e.getKeyChar()=='a')
          displayType = 0;
        if(e.getKeyChar()=='b')
          displayType = 1;
        repaint();
      }
     });
     
   }

   public void paintComponent(Graphics g)
   {
     Color oldColor = g.getColor();
     g.setColor(Color.white);
     g.fillRect(0,0,getWidth(),getHeight());
     g.setColor(oldColor);
     if(displayType==0)
     {
       for(int i=0;i<getWidth();i++)
       {
         for(int j=0;j<getHeight();j++)
         {
           int k = closestPoint(i,j);
           Color c = g.getColor();
           g.setColor(getRegionColor(k));
           g.fillRect(i,actualY(j),1,1);
           g.setColor(c);
         }
       }
     }
     else
     {
       for(int i=0;i<getWidth();i++)     
       {
         for(int j=0;j<getHeight();j++)
         {
           boolean nucp = isNonUniqueClosestPoint(i,j); 
           //Color c = g.getColor(); 
           //g.setColor(getRegionColor(k));
           if(nucp)
             g.fillRect(i,actualY(j),1,1);
           //g.setColor(c);
         }
       }
     }
    
     for(int i=0;i<points.size();i++)
     {
       Point p = (Point)points.get(i);
       g.fillRect((int)p.getX()-2,(int)p.getY()-2,4,4);
     } 
   }

   public int closestPoint(int x,int y)
   {
     double[] distances = new double[points.size()]; 
     for(int i=0;i<points.size();i++)
     {
       Point p = (Point)points.get(i);	
       distances[i] = distance(p.getX(),actualY((int)p.getY()),
                               (double)x,(double)y);
     }
     int closest = 0;
     for(int i=0;i<distances.length;i++)
     {
       if(distances[i] < distances[closest])
         closest = i;
     }
     return closest;
   } 

   public boolean isNonUniqueClosestPoint(int x,int y)
   {
     double[] distances = new double[points.size()];
     for(int i=0;i<points.size();i++)
     {
       Point p = (Point)points.get(i);
       distances[i] = distance(p.getX(),actualY((int)p.getY()),
                               (double)x,(double)y);
     }
     int closest1 = 0;
     for(int i=0;i<distances.length;i++)
     {
       if(distances[i] < distances[closest1])
         closest1 = i;
     }
     int closest2 = 0;
     for(int i=0;i<distances.length;i++)
     {
       if(distances[i] < distances[closest2] && i!=closest1)
         closest2= i;
     }
     if(Math.abs(distances[closest1]-distances[closest2]) < threshold && 
        closest1 != closest2)
       return true;
     else
       return false;
   }

   public double distance(double x1,double y1,double x2, double y2)
   {
     if(type==0)
       return Math.abs(x2-x1) + Math.abs(y2-y1);
     if(type==1)
       return Math.max(Math.abs(x2-x1),Math.abs(y2-y1));
     return Math.exp(Math.log(Math.abs(x2-x1)*Math.abs(x2-x1) + Math.abs(y2-y1)*Math.abs(y2-y1)*.5));
   }

   public int actualY(int y)
   {
     return getHeight() - y;
   }

   public Color getRegionColor(int i)
   {
     return new Color(255-i*20,255-i*20,255-i*20);
   }
}