SimplePong
//SimplePong is a java applet written by Daniel Moscufo
//of scufo http://www.esearch.com.au/scufo. It can be
//considered freeware.
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.lang.Math;
import java.net.*;
import java.awt.image.*;
public class SimplePong extends Applet
{
public void init()
{
//Set default colour=black, width=300, height=80
//Difficulty =5, image = backing.gif
int bcRed = 0;
int bcBlue = 0;
int bcGreen = 0;
int Width = 300;
int Height = 80;
int Difficulty = 5;
String backimage = "backing.gif";
//Check for user parameters
if(getParameter("Red")!=null)
bcRed = new Integer(getParameter("Red").trim()).intValue();
if(getParameter("Blue")!=null)
bcBlue = new Integer(getParameter("Blue").trim()).intValue();
if(getParameter("Green")!=null)
bcGreen = new Integer(getParameter("Green").trim()).intValue();
if(getParameter("Width")!=null)
Width = new Integer(getParameter("Width").trim()).intValue() -20;
if(getParameter("Height")!=null)
Height = new Integer(getParameter("Height").trim()).intValue()-20;
if(getParameter("Difficulty")!=null)
Difficulty = new Integer(getParameter("Difficulty").trim()).intValue();
if(getParameter("BackImage")!=null)
backimage= getParameter("BackImage");
//Set these above values
setBackground(new Color(bcRed,bcGreen,bcBlue));
Image ball = getImage(getCodeBase(), "ball.gif");
Image paddle1 = getImage(getCodeBase(),"panel1.gif");
Image paddle2 = getImage(getCodeBase(),"panel2.gif");
Image back = getImage(getCodeBase(),backimage);
Image toplay = getImage(getCodeBase(),"Toplay.gif");
//Create new Pongtable with correct values
PongTable pongtable = new PongTable(Width,Height,ball,paddle1,paddle2,back,toplay, Difficulty);
//this below code is just to add a centered pong game
setLayout(new BorderLayout());
Panel centredpanel = new Panel();
centredpanel.add(pongtable);
add(centredpanel, "Center");
}
}
class PongTable extends Canvas implements Runnable, MouseMotionListener, MouseListener
{
int Xsize, Ysize, Xball, Yball, Xbat, Ybat, XbatC, YbatC, difficulty;
double direction[] = new double[2];
Thread thisthread;
int Xbatdir[] = new int[2];
int Ybatdir[] = new int[2];
boolean Centred = true;
Image ball, paddle1, paddle2, back, toplay;
//AudioClip pong;
PongTable(int xsize, int ysize, Image Ball, Image Paddle1, Image Paddle2, Image Back, Image Toplay, int Difficulty)
{
//This method just setups all the variables
Toolkit toolkit = Toolkit.getDefaultToolkit();
addMouseMotionListener(this);
addMouseListener(this);
setSize(xsize,ysize);
Xsize = xsize;
Ysize = ysize;
startpositions();
Xball = (int)Xsize/2;
Yball = (int)Ysize/2;
direction[0] = 0;
direction[1] = 0;
ball = Ball;
paddle1 = Paddle1;
paddle2 = Paddle2;
back = Back;
toplay = Toplay;
difficulty = Difficulty;
//Start the thread.
thisthread = new Thread(this);
thisthread.start();
}
void startpositions()
{
//Specify the start positions
Xball = 20;
Yball = 20;
Xbat = 20;
Ybat = 40;
XbatC = Xsize -20;
YbatC = 40;
direction[0] = 4.0; //X velocity vector
direction[1] = 4.0; //Y velocity vector
}
public void update(Graphics g)
{
//This is just your standard double buffering update method
Graphics offgraph;
Image offscreen = null;
Dimension d = getSize();
offscreen = createImage(d.width, d.height);
offgraph = offscreen.getGraphics();
offgraph.setColor(getBackground());
offgraph.fillRect(0, 0, d.width, d.height);
offgraph.setColor(getForeground());
paint(offgraph);
g.drawImage(offscreen, 0, 0, this);
offscreen.flush();
}
public void paint(Graphics g)
{
//Draw Background Image
g.drawImage(back,5,5,Xsize-10,Ysize-10,this);
//Draw users bat
g.drawImage(paddle1,XbatC-2,YbatC-10,this);
//Draw computer bat
g.drawImage(paddle2,Xbat-2,Ybat-10,this);
//draw ball
g.drawImage(ball,Xball-5, Yball-5,this);
//check if no one is playing and display "click to play"
if(Centred)
g.drawImage(toplay,10, 10,this);
}
public void run()
{
double Xballdb, Yballdb;
Xballdb = Xball;
Yballdb = Yball;
int n;
while(true)
{
//We check for ball hitting surface 4 times for every repaint()
for(n=0;n<4;n++)
{
//increase X & Y by velocity/4
Xballdb = Xballdb + direction[0]/4;
Yballdb = Yballdb + direction[1]/4;
//check if ball hit either "goal"
//centred tells that game is over
if(Xballdb<10 || Xballdb>Xsize-10)
{
Xballdb = Xsize/2;
Yballdb = Ysize/2;
direction[0] = 0;
direction[1] = 0;
Centred = true;
}
//Check if ball hits either top or bottom wall
// if so change y to = -y
if(Yballdb<10 || Yballdb>Ysize-10)
{
direction[1]=-1*direction[1];
}
//Now we see if bat hits players bat
if(Xballdb>18 && Xballdb<27)//X thickness of bat
//check if ball is within 10 pixels Y dirn
//of bat
if(Math.abs(Yballdb-Ybat)<=10)
{
//if so x = -x + x bat movement dirn,
//y = -y + y bat movement dirn
direction[0] = -1*direction[0]+(int)((Xbatdir[0]-Xbatdir[1])/8);
direction[1] = direction[1]+(int)((Ybatdir[0]-Ybatdir[1])/8);
//place ball at front of bat
Xballdb=28;
}
//Now we do the same for computer bat
if(Xballdb<(Xsize-15) && Xballdb>(Xsize-22))
if(Math.abs(Yballdb-YbatC)<=10)
{
//x = -x - random no.
direction[0] = -1*direction[0] + -1*Math.random();
//y = -y + random no proportional to x speed
//This helps in stopping the ball going
//back and further on same y value
direction[1] = direction[1] + (direction[0]/4)*Math.sin(Math.random()*2*Math.PI);
//place ball on front of bat
Xballdb=Xsize-23;
}
}
//send paint correct coords
Xball = (int)Xballdb;
Yball = (int)Yballdb;
//ok now do Computer AI
//check ball in our half
if(Xball>Xsize/2)
{
//ok this algorithym is simple but effective
//firstly check the bat and ball aren't the same height
//then find if bat is above or below the bat
//then move bat up/down by difficulty pixels
if((Yball-YbatC)!=0)
YbatC = (Yball-YbatC)/(Math.abs(Yball-YbatC))*difficulty + YbatC;
}
//recall the paint method
repaint();
//Ok sleep the thread fo 50 ms
try
{
thisthread.sleep(50);
}
catch(Exception e)
{
System.out.println("Error on sleep");
}
}
}
public void mouseMoved(MouseEvent e)
{
int x = e.getX();
int y = e.getY();
//Ok here we move the bat by setting it equal to mouse height
if(y>15 && y<Ysize-10)
{
Ybat = y;
//below we set up the bat movement dir'n. so the player
//can influence the ball dir'n.
Xbatdir[1] = Xbatdir[0];
Ybatdir[1] = Ybatdir[0];
Xbatdir[0] = x;
Ybatdir[0] = y;
}
repaint();
}
public void mouseDragged(MouseEvent e)
{
}
public void mousePressed(MouseEvent e)
{
}
public void mouseReleased(MouseEvent e)
{
}
public void mouseClicked(MouseEvent e)
{
//Check if "start new game"
if(Centred)
{
startpositions();
Centred = false;
}
}
public void mouseEntered(MouseEvent e)
{
}
public void mouseExited(MouseEvent e)
{
}
}
Back to the SimplePong applet page.
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