//
//
//  Pong - Java Pong Game
//
//  Copyright (c) 2004-2007 by Knute Johnson.  All rights reserved.
//  
//  Version 1.4 - 15 Apr 2007 - bug fix contributed by Phillip, ball could get
//                               stuck on top edge, remove some of the null
//                               spot at center of paddle to improve
//                               playability and housekeeping
//          1.3 - 09 Feb 2004 - add speed increase and improve playability
//          1.2 - 09 Feb 2004 - change code to make it 1.1 compatible
//          1.1 - 09 Feb 2004 - change static Colors to pre 1.4
//          1.0 - 08 Feb 2004 - incept
//
//

package com.knutejohnson.games.pong;

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

public class Pong extends Applet implements Runnable {
    static final String info = "Pong 1.4 - Copyright \u00a9 2004-2007 " +
     "Knute Johnson.  All rights reserverd.";
    Thread thread;
    Image osi;                      // offscreen image for double buffering
    Graphics osg;                   // graphics of offscreen image

    int width,height;               // dimensions of applet

    int ballX,ballY;                // position of ball
    int veloX,veloY;                // speed of ball
    int paddleX,paddleY;            // location of paddle center
    
    AudioClip bink,bonk,buhh;       // sound effects
    
    public void init() {
        width = getSize().width;
        height = getSize().height;
        ballX = width / 2;
        ballY = 1;
        paddleX = width / 2;
        paddleY = height - 20;

        osi = createImage(width,height);    // create offscreen image
        osg = osi.getGraphics();            // get its graphics

        bink = getAudioClip(getClass().getResource("sounds/bink.wav"));
        bonk = getAudioClip(getClass().getResource("sounds/bonk.wav"));
        buhh = getAudioClip(getClass().getResource("sounds/buhh.wav"));

        enableEvents(MouseEvent.MOUSE_MOVED|MouseEvent.MOUSE_PRESSED);
    }

    public void start() {
        thread = new Thread(this);
        thread.start();
    }

    public void stop() {
        thread.interrupt();
    }

    public void processMouseMotionEvent(MouseEvent me) {
        // paddle follows mouse movement
        paddleX = me.getX();
        if (paddleX < 20)
            paddleX = 20;
        else if (paddleX > width - 20)
            paddleX = width - 20;
    }

    public void processMouseEvent(MouseEvent me) {
        // release ball on mouse click
        if (me.getID() == MouseEvent.MOUSE_PRESSED) {
            ballX = width / 2;
            ballY = 1;
            veloX = 0;
            veloY = 6;
        }
    }
    
    public void run() {
        try {
            while (true) {
                // determine new ball position
                ballX += veloX;
                ballY += veloY;
                
                // if ball is hitting left or right edge, bounce off
                if (ballX <= 5 || ballX >= width - 5) {
                    veloX = -veloX;
                    bink.play();
                // if ball is hitting top bounce off
                } 
                if (ballY <= 0) {
                    veloY = -veloY;
                    bink.play();
                // if ball has reached the bottom
                }
                if (ballY > height - 5) {
                    ballX = width / 2;
                    ballY = 1;
                    veloX = veloY = 0;
                    buhh.play();
                // if ball is at paddle height
                }
                if (ballY > height - 30) {
                    // if ball is within paddle width
                    if (ballX >= paddleX - 3 && ballX <= paddleX + 3) {
                        veloY = -veloY;
                        // 3 pixel wide null
                        if (veloX == 0 && Math.abs(ballX - paddleX) > 1) {
                            if (ballX < paddleX)
                                --veloX;
                            else if (ballX > paddleX)
                                ++veloX;
                        }
                        bonk.play();
                    } else if (ballX >= paddleX - 10 && ballX <= paddleX + 10) {
                        if (ballX < paddleX)
                            --veloX;
                        else if (ballX > paddleX)
                            ++veloX;
                        veloY = -veloY;
                        bonk.play();
                    } else if (ballX >= paddleX - 17 && ballX <= paddleX + 17) {
                        if (ballX < paddleX)
                            veloX -= 2;
                        else if (ballX > paddleX)
                            veloX += 2;
                        veloY = -veloY;
                        bonk.play();
                    } else if (ballX >= paddleX - 25 && ballX <= paddleX + 25) {
                        if (ballX < paddleX)
                            veloX -= 4;
                        else if (ballX > paddleX)
                            veloX += 4;
                        veloY = -veloY;
                        // increase y velocity if hit on edge of paddle
                        if (veloY > 0)
                            ++veloY;
                        else
                            --veloY;
                        bonk.play();
                    }
                }
                    
                // draw background
                osg.setColor(Color.gray);
                osg.fillRect(0,0,width,height);
                osg.setColor(Color.white);
                // draw ball
                osg.fillRect(ballX-5,ballY,10,10);
                // draw paddle
                osg.fillRect(paddleX-20,paddleY,40,10);            

                repaint();            
            
                Thread.sleep(30);       // 30 frames per second
            }
        } catch (InterruptedException ie) { }
    }

    public void paint(Graphics g) {
        g.drawImage(osi,0,0,width,height,this);
    }

    public void update(Graphics g) {
        paint(g);
    }

    public String getAppletInfo() {
        return info;
    }
}