import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class Eyes {

  // Animated eyes that follow the cursor.  
  // Author: Caitlin Little, December 27, 1996

  Point left, right, leftPupil, rightPupil;
  final int 
    EYE_RADIUS = 30,
    PUPIL_RADIUS = 10;
  
  public Eyes(Point c) {
    left = new Point(c.x-EYE_RADIUS-3, c.y); 
    right = new Point(c.x+EYE_RADIUS+3, c.y);
  }
  
  private void fillCircle (Graphics g, 
                           Point center, int radius) {
  // Utility method: an abbreviated 
  // way to draw a filled circle.
    g.fillOval(center.x-radius, center.y-radius, 
               2*radius, 2*radius);
  }
  
  public void stare (Graphics g, Point cursor) {
  
    // Draw the white eyes
    g.setColor(Color.white);
    fillCircle(g, left, EYE_RADIUS);
    fillCircle(g, right, EYE_RADIUS);
  
    // Draw the pupils
    g.setColor(Color.black);
    leftPupil = compute (cursor, left);
    fillCircle(g, leftPupil, PUPIL_RADIUS);
    rightPupil = compute (cursor, right);
    fillCircle(g, rightPupil, PUPIL_RADIUS);
  }
  
  private Point compute (Point cursor, Point eye) {
  // Compute the location of the pupil, given the
  // locations of the eye and the cursor.
    double d = Math.sqrt((cursor.x-eye.x)*(cursor.x-eye.x)
                       + (cursor.y-eye.y)*(cursor.y-eye.y));
    int r = EYE_RADIUS - PUPIL_RADIUS;
    return new Point (eye.x + (int)((cursor.x-eye.x)*r/d),
                      eye.y + (int)((cursor.y-eye.y)*r/d));
  }
}