/* Eyes.java by Shane Harper, Jan 2002 */
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;


public class Eyes extends Applet implements MouseMotionListener {
    final int EYE_WIDTH = 50;
    final int EYE_HEIGHT = 65;
    final int EYE_SPACING = 5;

    Eye left, right;

    public void init() {
        addMouseMotionListener(this);

        left = new Eye((size().width-EYE_SPACING)/2-EYE_WIDTH,
                (size().height-EYE_HEIGHT)/2,
                EYE_WIDTH, EYE_HEIGHT);
        right = new Eye((size().width+EYE_SPACING)/2,
                (size().height-EYE_HEIGHT)/2,
                EYE_WIDTH, EYE_HEIGHT);
    }

    public void paint(Graphics g) {
        g.setColor(Color.blue);
        g.drawRect(0, 0, size().width-1, size().height-1);

        left.paint(g);
        right.paint(g);
    }

    public void mouseMoved(MouseEvent e) {
        Graphics g = getGraphics();
        left.update(g, e.getX(), e.getY());
        right.update(g, e.getX(), e.getY());
    }

    public void mouseDragged(MouseEvent e) {
        mouseMoved(e);
    }
}


class Eye {
    final double IRIS_SIZE = 0.15;
    final double MAX_IRIS_DISPLACEMENT = 0.25;
    final double BORDER_SIZE = 0.1;

    int x, y;
    int width, height;
    int irisX, irisY;

    void paintIris(Graphics g) {
        final int iW = (int)(IRIS_SIZE*width);
        final int iH = (int)(IRIS_SIZE*height);
        g.fillOval(irisX-(iW/2) , irisY-(iH/2), iW, iH);
    }

    public void paint(Graphics g) {
        g.setColor(Color.black);
        g.fillOval(x, y, width, height);
        g.setColor(Color.white);
        g.fillOval(x+(int)(BORDER_SIZE*width), y+(int)(BORDER_SIZE*height),
                (int)((1.0 - 2*BORDER_SIZE)*width),
                (int)((1.0 - 2*BORDER_SIZE)*height));
        g.setColor(Color.black);
        paintIris(g);
    }

    public void update(Graphics g, int mousePointerX, int mousePointerY) {
        g.setColor(Color.white);
        paintIris(g);

        final int centerX = x + (width/2);
        final int centerY = y + (height/2);

        // the x co-ordinate is scaled so that the eye is distorted to become
        // circular which simplifies the geometric calculation
        final int dX = (int)((mousePointerX - centerX) * (height/width));
        final int dY = mousePointerY - centerY;

        final int dMousePointer = (int)(Math.sqrt( (dX*dX)+(dY*dY) ));
        final int dMaxDisp = (int)(MAX_IRIS_DISPLACEMENT*height);

        final float scale = (dMousePointer <= dMaxDisp)
                                            ? 1 : (float)dMaxDisp/dMousePointer;
        irisY = centerY + (int)(dY * scale);
        irisX = centerX + (int)(dX * scale * width/height);

        g.setColor(Color.black);
        paintIris(g);
    }

    public Eye(int x, int y, int width, int height) {
        this.x = x; this.y = y;
        this.width = width; this.height = height;
        irisX = x + (width/2);
        irisY = y + (height/2);
    }
}