/* The Genuts Project - http://www.genuts.com */

import java.applet.*;

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

import com.genuts.gameui.*;

/**
  * This applet, named "Remote Control" and figuring a joystick, allows moving the "RC Toy" applet's cursor.
  */
public class RemoteControl extends Applet 
	implements MouseListener, MouseMotionListener {

	PlayField f;

	int xb, yb;
	int d;
	int w, h;
	int p;
	int xc, yc;
	int L;
	int s;
	int H;
	int xc2, yc2;
  
	public void init() {

		// width & height
		w = getSize().width;
		h = getSize().height;

		// depth
		p = (int)(Math.min(w,h)*0.05);

		// diameter of the ball
		d = (int)(Math.min(w,h)*0.35);

		// stick thickness
		s = d/3;

		// center
		xc = (w-p)/2;
		yc = (h-p)/2;

		// ball's height
		H = p*2;

		// center
		xc2 = xc-H;
		yc2 = yc-H;

		// liberty length (radius)
		L = Math.min(w,h)/2-d/2-H-p;
		
		// initial ball placement
		xb = xc-H;
		yb = yc-H;

		setLayout(new BorderLayout());

		f = new PlayField(w,h) {

			public void paintPlayField(Graphics g) {

				// bg
				g.setColor(Color.white);
				g.fillRect(0,0,w,h);

				// box
				g.setColor(new Color(204,204,204));
				g.fillRect(0+w/4,0+h/4,w-p-w/2,h-p-h/2);

				g.setColor(new Color(102,102,102));
				int tx1[] = {w-p-w/4,w-w/4,w-w/4,w-p-w/4};
				int ty1[] = {0+h/4,p+h/4,h-h/4,h-p-h/4};
				g.fillPolygon(tx1, ty1, 4);

				g.setColor(new Color(153,153,153));
				int tx2[] = {0+w/4,w-p-w/4,w-w/4,p+w/4};
				int ty2[] = {h-p-h/4,h-p-h/4,h-h/4,h-h/4};
				g.fillPolygon(tx2, ty2, 4);

				// stick
				g.setColor(new Color(102,102,102));
				g.fillOval(xc-s/2,yc-s/2,s,s);
				drawThickLine(g, xc, yc, xb, yb, s);

				// ball
				g.setColor(Color.red);
				g.fillOval(xb-d/2,yb-d/2,d,d);

				g.setColor(Color.white);
				g.fillOval(xb-d/4,yb-d/4,d/6,d/6);

			}
		
		};

		f.setSleepTime(1000/25);

		f.setDisplayManager(null);

		f.addMouseListener(this);
		f.addMouseMotionListener(this);

		add(f,BorderLayout.CENTER);
	}

	public void start() {
		f.setPause(false);
    }

    public void stop() {
		f.stop();
    }

	public void mouseClicked(MouseEvent e) {
		// Nothing
	}

	public void mouseEntered(MouseEvent e) {
		showStatus(getAppletInfo());
	}

	public void mouseExited(MouseEvent e) {
		showStatus("");
	}

	public String getAppletInfo() {
		return "Remote Control";
	}

	public void mousePressed(MouseEvent e) {
		moveBall(e.getX(),e.getY());
	}

	void moveBall(int nx, int ny) {

		xb = nx;
		yb = ny;

		// limit xb & yb to a LxL square
		if (xb > xc2+L) xb = xc2+L;
		else if (xb < xc2-L) xb = xc2-L;

		if (yb > yc2+L) yb = yc2+L;
		else if (yb < yc2-L) yb = yc2-L;

		f.repaint();

		sendXY();
	}

	void sendXY() {
		int x,y;
		double l = Math.sqrt(Math.pow(xb-xc2,2)+Math.pow(yb-yc2,2));
		x = (xb-xc2)*100/L;
		y = (yb-yc2)*100/L;

		// The "Remote Control" applet try to find the "RC Toy" 
	    // applet by looking it up by name, specified with a 
		// <PARAM> tag, using the AppletContext getApplet 
	    // method.
		Applet rc = null;
		String name = getParameter("RC");
		rc = getAppletContext().getApplet(name);

		if (rc != null) {
		    if (!(rc instanceof RemotelyControllable)) {
				//System.out.println("Found applet named " + rc + ", " + "but it's not a RemotelyControllable.");
			} else {
				//System.out.println("Found applet named " + rc + ". Sending message to it.");
				
				// The "Remote Control" sends a message by invoking 
				// the "RC Toy" applet's method.
		        ((RemotelyControllable)rc).setXY(x,y);
			}
		}
	}

	public void mouseReleased(MouseEvent e) {
		moveBall(xc2,yc2);
	}

	public void mouseDragged(MouseEvent e) {
		moveBall(e.getX(),e.getY());
	}

	public void mouseMoved(MouseEvent e) {
		// Nothing
	}

	/**
	  * From Real's HowTo, http://www.rgagnon.com/
	  */
	public void drawThickLine(Graphics g, 
		int x1, int y1, 
		int x2, int y2, 
		int thickness) {

		// The thick line is in fact a filled polygon
		int dX = x2 - x1;
		int dY = y2 - y1;
	  
		// line length
		double lineLength = Math.sqrt(dX * dX + dY * dY);

		double scale = (double)(thickness) / (2 * lineLength);

		// The x and y increments from an endpoint needed to create a rectangle...
		double ddx = -scale * (double)dY;
		double ddy = scale * (double)dX;
		ddx += (ddx > 0) ? 0.5 : -0.5; 
		ddy += (ddy > 0) ? 0.5 : -0.5;   
		int dx = (int)ddx;
		int dy = (int)ddy;

		// Now we can compute the corner points...
		int xPoints[] = new int[4];
		int yPoints[] = new int[4];

		xPoints[0] = x1 + dx; yPoints[0] = y1 + dy;
		xPoints[1] = x1 - dx; yPoints[1] = y1 - dy;
		xPoints[2] = x2 - dx; yPoints[2] = y2 - dy;
		xPoints[3] = x2 + dx; yPoints[3] = y2 + dy;

		g.fillPolygon(xPoints, yPoints, 4);
	}
}