// Ant.java

import java.awt.*;

class Ant
{
   public Ant ()
   {  _x       = 0D;
      _y       = 0D;
      _vx      = 0D;
      _vy      = 0D;
      _turn    = 0D;
      _heading = 0D;
      _fx      = 0D;
      _fy      = 0D;
      _speed   = 3D;
      _roSpeed = 0.1D;
      _timer   = 0;
      _sTimer  = 0;
      _target  = null;
      _dx      = 0D;
      _dy      = 0D;
      _dTarget = 0D;
      _color   = Color.red;
      _mode    = DEAD;
   }

   public static void SetBounds   (double mx, double my)   {_maxX   = mx;
                                                            _maxY   = my;}
   public void        SetColor    (Color c)                {_color  = c;}
   public void        SetMode     (int i)                  {_mode   = i;}
   public void        SetTarget   (Ant ant)                {_target = ant;}
   public void        SetPosition (double ix, double iy)   {_x      = ix;
                                                            _y      = iy;}
   public void Display (Graphics g)
   {  g.setColor (_color);
     Polygon polygon = new Polygon ();
      polygon.addPoint ((int)(_x + _vx * 1.6D), (int)(_y + _vy * 1.6D));
      polygon.addPoint ((int)(_x + Math.cos(_heading + 5D) * 3D),
                        (int)(_y + Math.sin(_heading + 5D) * 3D));
      polygon.addPoint ((int)(_x + Math.cos(_heading - 5D) * 3D),
                        (int)(_y + Math.sin(_heading - 5D) * 3D));
      g.fillPolygon (polygon);
      g.drawLine ((int)_x, (int)_y, (int)(_x + _vx * 2.3D),
                                    (int)(_y + _vy * 2.3D));
   }

   public void Move ()
   {  _heading += _turn;
      _vx = Math.cos (_heading) * _speed;
      _vy = Math.sin (_heading) * _speed;
      _x += _vx;  _y += _vy;
      _x += _fx;  _y += _fy;
   // wrap
      if (_x > _maxX) _x -= _maxX;  else if (_x < 0D) _x += _maxX;
      if (_y > _maxY) _y -= _maxY;  else if (_y < 0D) _y += _maxY;
   }

   public void Think ()
   {  switch (_mode) {
         case SEARCHING:
            if (--_timer  == 0) {_mode = TRACKING;  break;}
           int i = (int)(Math.random() * 100D) - _sTimer;
            if (--_sTimer == 0) {_turn = 0D;  break;}
            if (i <= 100)  break;
            _turn = ((i & 1) == 1) ? _roSpeed : -_roSpeed;
            _sTimer = (int)(Math.random() * 10D);
            break;
         case TRACKING:
            _dx = _target._x - _x;
            _dy = _target._y - _y;
           double d  = _dx + Math.cos(_heading) * _speed;
           double d2 = _dy + Math.sin(_heading) * _speed;
           double d4 = d * d + d2 * d2;
            if (d4 <= 10D) {_turn = 0.0D;}
            else {
              double d1 = _dx + Math.cos (_heading + _roSpeed) * _speed;
              double d3 = _dy + Math.sin (_heading + _roSpeed) * _speed;
              double d5 = d1 * d1 + d3 * d3;
               d1 = _dx + Math.cos (_heading - _roSpeed) * _speed;
               d3 = _dy + Math.sin (_heading - _roSpeed) * _speed;
              double d6 = d1 * d1 + d3 * d3;
               if (d4 < 100D && Math.abs ((d6 - d5) / 2D) > 0.01D)
                  {_mode = SEARCHING;  _timer = (int)(Math.random() * 50D) + 5;}
               if      (d5 < d6) {_turn = (d5 < d4) ? -_roSpeed : 0D;}
               else if (d6 < d5) {_turn = (d6 < d4) ?  _roSpeed : 0D;}
               else              {_turn = 0.0D;}
            }
            _dTarget = d4;
            break;
         default:
            break;
      }
   }

   static double _maxX;
   static double _maxY;
   public double _x;
   public double _y;
   public double _vx;
   public double _vy;
   public double _turn;
   public double _heading;
   public double _fx;
   public double _fy;
   public double _speed;
   public double _roSpeed;
   public int    _timer;
   public int    _sTimer;
   public Ant    _target;
   public double _dx;
   public double _dy;
   public double _dTarget;
   public int    _mode;
   public Color  _color;
   public static final int DEAD      = 0;
   public static final int TRACKING  = 1;
   public static final int SEARCHING = 2;
}