Posts Tagged ‘programming’

Json + JqueryThere is no direct way to iterate over a Java List with jQuery, see the following case study : Spring controller @RequestMapping(value = “/”, method = RequestMethod.GET) public ModelAndView getPages() { List list = new ArrayList(); list.add(“List A”); list.add(“List B”); list.add(“List C”); list.add(“List D”); list.add(“List E”); ModelAndView model = new ModelAndView(“somepage”); model.addObject(“list”, list); return model; } JSP page, you can…

 

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DebuggingPHP a well-known scripting language used for web development or we can say PHP is the most used scripting language in today’s web industry. Even most of popular CMSs are also developed and support PHP which makes PHP more popular as well. As the users increases respectively (to use PHP language for web development) there is need of PHP debuggers also increase. Because everyone wants that their code should be fine and error free. Debugger tool helps you in debugging errors in web applications and scripts by which makes innovative web development easy. In This post I have mentioned top 10 widely used PHP debuggers by developer, have a look.

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imagesIn OO Programming, we often hear of terms like “Class”, “Object” and “Instance”; but what actually is a Class / Object / Instance?

In short, An object is a software bundle of related state and behavior. A class is a blueprint or prototype from which objects are created. An instance is a single and unique unit of a class.

Example, we have a blueprint (class) represents student (object) with fields like name, age, course (class member). And we have 2 students here, Foo and Bob. So, Foo and Bob is 2 different instances of the class (Student class) that represent object (Student people).

Let me go into details…

Object
Real world objects shares 2 main characteristics, state and behavior. Human have state (name, age) and behavior (running, sleeping). Car have state (current speed, current gear) and state (applying brake, changing gear). Software objects are conceptually similar to real-world objects: they too consist of state and related behavior. An object stores its state in fields and exposes its behavior through methods.

Class
Class is a “template” / “blueprint” that is used to create objects. Basically, a class will consists of field, static field, method, static method and constructor. Field is used to hold the state of the class (eg: name of Student object). Method is used to represent the behavior of the class (eg: how a Student object going to stand-up). Constructor is used to create a new Instance of the Class.

Instance
An instance is a unique copy of a Class that representing an Object. When a new instance of a class is created, the JVM will allocate a room of memory for that class instance.

logging

There are some examples out there, but I’ve found that most of are either too complicated or are too specific.
In the end I decided that the only way to fix the problem is to write a general tutorial on Log4Net configuration myself.

Basics

Use NuGet to download and install the latest version of Log4Net.

nuget

Config files

Now you need to configure Log4Net.

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Are you looking for image upload and Resize PHP script. I had implemented a simple PHP script to re-sizing image into different dimensions. It’s very useful to your web projects to save hosting space and bandwidth to reduce the original image to compressed size.

PHP Code
This script resize an Image into two 60px and 25px. Take a look at $newwidth you have to modify size values.

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This tutorial about my favorite place Dzone like data loading while page scrolling down with jQuery and PHP. We have lots of data but can not display all. This script helps you to display little data and make faster your website.
Load Data while Scrolling Page Down with jQuery and  PHP

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The Java programming language is a strongly-typed language and it consist of eight primitive data types (byte, short, int, long, float, double, boolean, char). For more about java primitive data type, please visit http://java.sun.com/docs/books/tutorial/java/nutsandbolts/datatypes.html

Well, sometime we really need to know what is the limit of the primitive types in java. With following simple code, we can print out the limit of each of the java primitive data types (except boolean and char) 🙂

public class PrintTypeLimit
{
    public static void main(String args[]) {        System.out.println("Min byte value   = " + Byte.MIN_VALUE);
        System.out.println("Max byte value   = " + Byte.MAX_VALUE);
        System.out.println("Min short value  = " + Short.MIN_VALUE);
        System.out.println("Max short value  = " + Short.MAX_VALUE);
        System.out.println("Min int value    = " + Integer.MIN_VALUE);
        System.out.println("Max int value    = " + Integer.MAX_VALUE);
        System.out.println("Min long value    = " + Long.MIN_VALUE);
        System.out.println("Max long value    = " + Long.MAX_VALUE);
        System.out.println("Min float value  = " + Float.MIN_VALUE);
        System.out.println("Max float value  = " + Float.MAX_VALUE);
        System.out.println("Min double value = " + Double.MIN_VALUE);
        System.out.println("Max double value = " + Double.MAX_VALUE);
    }
}

 

Output

Min byte value   = -128
Max byte value   = 127
Min short value  = -32768
Max short value  = 32767
Min int value    = -2147483648
Max int value    = 2147483647
Min long value    = -9223372036854775808
Max long value    = 9223372036854775807
Min float value  = 1.4E-45
Max float value  = 3.4028235E38
Min double value = 4.9E-324
Max double value = 1.7976931348623157E308

 

In this part of the Java 2D games tutorial we will create a simple Pacman game clone.

Pacman is an arcade game originally developed by a Japanese company Namco in 1980. Pacman became one of the most popular arcade games ever.

Development

The following code example is a remake of a Pacman game by Brian Postma available at javaboutique. I have modified and simplified the code. So that it is easier to understand.

The goal of the game is to collect all the points in the maze and avoid the ghosts. The pacman is animated in two ways. His position in the maze and his body. We animate his body with four images, depending on the direction. The animation is used to create the illusion of pacman opening and closing his mouth. The maze consists of 15 x 15 squares. The structure of the maze is based on a simple array of integers. Pacman has three lives. We also count the score.

The game consists of two files.

Board.java
package pacman;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Event;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.Timer;

public class Board extends JPanel implements ActionListener {

    Dimension d;
    Font smallfont = new Font("Helvetica", Font.BOLD, 14);

    FontMetrics fmsmall, fmlarge;
    Image ii;
    Color dotcolor = new Color(192, 192, 0);
    Color mazecolor;

    boolean ingame = false;
    boolean dying = false;

    final int blocksize = 24;
    final int nrofblocks = 15;
    final int scrsize = nrofblocks * blocksize;
    final int pacanimdelay = 2;
    final int pacmananimcount = 4;
    final int maxghosts = 12;
    final int pacmanspeed = 6;

    int pacanimcount = pacanimdelay;
    int pacanimdir = 1;
    int pacmananimpos = 0;
    int nrofghosts = 6;
    int pacsleft, score;
    int deathcounter;
    int[] dx, dy;
    int[] ghostx, ghosty, ghostdx, ghostdy, ghostspeed;

    Image ghost;
    Image pacman1, pacman2up, pacman2left, pacman2right, pacman2down;
    Image pacman3up, pacman3down, pacman3left, pacman3right;
    Image pacman4up, pacman4down, pacman4left, pacman4right;

    int pacmanx, pacmany, pacmandx, pacmandy;
    int reqdx, reqdy, viewdx, viewdy;

    final short leveldata[] =
    { 19, 26, 26, 26, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 22,
      21, 0,  0,  0,  17, 16, 16, 16, 16, 16, 16, 16, 16, 16, 20,
      21, 0,  0,  0,  17, 16, 16, 16, 16, 16, 16, 16, 16, 16, 20, 
      21, 0,  0,  0,  17, 16, 16, 24, 16, 16, 16, 16, 16, 16, 20, 
      17, 18, 18, 18, 16, 16, 20, 0,  17, 16, 16, 16, 16, 16, 20,
      17, 16, 16, 16, 16, 16, 20, 0,  17, 16, 16, 16, 16, 24, 20, 
      25, 16, 16, 16, 24, 24, 28, 0,  25, 24, 24, 16, 20, 0,  21, 
      1,  17, 16, 20, 0,  0,  0,  0,  0,  0,  0,  17, 20, 0,  21,
      1,  17, 16, 16, 18, 18, 22, 0,  19, 18, 18, 16, 20, 0,  21,
      1,  17, 16, 16, 16, 16, 20, 0,  17, 16, 16, 16, 20, 0,  21, 
      1,  17, 16, 16, 16, 16, 20, 0,  17, 16, 16, 16, 20, 0,  21,
      1,  17, 16, 16, 16, 16, 16, 18, 16, 16, 16, 16, 20, 0,  21,
      1,  17, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 20, 0,  21,
      1,  25, 24, 24, 24, 24, 24, 24, 24, 24, 16, 16, 16, 18, 20,
      9,  8,  8,  8,  8,  8,  8,  8,  8,  8,  25, 24, 24, 24, 28 };

    final int validspeeds[] = { 1, 2, 3, 4, 6, 8 };
    final int maxspeed = 6;

    int currentspeed = 3;
    short[] screendata;
    Timer timer;

    public Board() {

        GetImages();

        addKeyListener(new TAdapter());

        screendata = new short[nrofblocks * nrofblocks];
        mazecolor = new Color(5, 100, 5);
        setFocusable(true);

        d = new Dimension(400, 400);

        setBackground(Color.black);
        setDoubleBuffered(true);

        ghostx = new int[maxghosts];
        ghostdx = new int[maxghosts];
        ghosty = new int[maxghosts];
        ghostdy = new int[maxghosts];
        ghostspeed = new int[maxghosts];
        dx = new int[4];
        dy = new int[4];
        timer = new Timer(40, this);
        timer.start();
    }

    public void addNotify() {
        super.addNotify();
        GameInit();
    }

    public void DoAnim() {
        pacanimcount--;
        if (pacanimcount <= 0) {
            pacanimcount = pacanimdelay;
            pacmananimpos = pacmananimpos + pacanimdir;
            if (pacmananimpos == (pacmananimcount - 1) || pacmananimpos == 0)
                pacanimdir = -pacanimdir;
        }
    }

    public void PlayGame(Graphics2D g2d) {
        if (dying) {
            Death();
        } else {
            MovePacMan();
            DrawPacMan(g2d);
            moveGhosts(g2d);
            CheckMaze();
        }
    }

    public void ShowIntroScreen(Graphics2D g2d) {

        g2d.setColor(new Color(0, 32, 48));
        g2d.fillRect(50, scrsize / 2 - 30, scrsize - 100, 50);
        g2d.setColor(Color.white);
        g2d.drawRect(50, scrsize / 2 - 30, scrsize - 100, 50);

        String s = "Press s to start.";
        Font small = new Font("Helvetica", Font.BOLD, 14);
        FontMetrics metr = this.getFontMetrics(small);

        g2d.setColor(Color.white);
        g2d.setFont(small);
        g2d.drawString(s, (scrsize - metr.stringWidth(s)) / 2, scrsize / 2);
    }

    public void DrawScore(Graphics2D g) {
        int i;
        String s;

        g.setFont(smallfont);
        g.setColor(new Color(96, 128, 255));
        s = "Score: " + score;
        g.drawString(s, scrsize / 2 + 96, scrsize + 16);
        for (i = 0; i < pacsleft; i++) {
            g.drawImage(pacman3left, i * 28 + 8, scrsize + 1, this);
        }
    }

    public void CheckMaze() {
        short i = 0;
        boolean finished = true;

        while (i < nrofblocks * nrofblocks && finished) {
            if ((screendata[i] & 48) != 0)
                finished = false;
            i++;
        }

        if (finished) {
            score += 50;

            if (nrofghosts < maxghosts)
                nrofghosts++;
            if (currentspeed < maxspeed)
                currentspeed++;
            LevelInit();
        }
    }

    public void Death() {

        pacsleft--;
        if (pacsleft == 0)
            ingame = false;
        LevelContinue();
    }

    public void moveGhosts(Graphics2D g2d) {
        short i;
        int pos;
        int count;

        for (i = 0; i < nrofghosts; i++) {
            if (ghostx[i] % blocksize == 0 && ghosty[i] % blocksize == 0) {
                pos =
 ghostx[i] / blocksize + nrofblocks * (int)(ghosty[i] / blocksize);

                count = 0;
                if ((screendata[pos] & 1) == 0 && ghostdx[i] != 1) {
                    dx[count] = -1;
                    dy[count] = 0;
                    count++;
                }
                if ((screendata[pos] & 2) == 0 && ghostdy[i] != 1) {
                    dx[count] = 0;
                    dy[count] = -1;
                    count++;
                }
                if ((screendata[pos] & 4) == 0 && ghostdx[i] != -1) {
                    dx[count] = 1;
                    dy[count] = 0;
                    count++;
                }
                if ((screendata[pos] & 8) == 0 && ghostdy[i] != -1) {
                    dx[count] = 0;
                    dy[count] = 1;
                    count++;
                }

                if (count == 0) {
                    if ((screendata[pos] & 15) == 15) {
                        ghostdx[i] = 0;
                        ghostdy[i] = 0;
                    } else {
                        ghostdx[i] = -ghostdx[i];
                        ghostdy[i] = -ghostdy[i];
                    }
                } else {
                    count = (int)(Math.random() * count);
                    if (count > 3)
                        count = 3;
                    ghostdx[i] = dx[count];
                    ghostdy[i] = dy[count];
                }

            }
            ghostx[i] = ghostx[i] + (ghostdx[i] * ghostspeed[i]);
            ghosty[i] = ghosty[i] + (ghostdy[i] * ghostspeed[i]);
            DrawGhost(g2d, ghostx[i] + 1, ghosty[i] + 1);

            if (pacmanx > (ghostx[i] - 12) && pacmanx < (ghostx[i] + 12) &&
                pacmany > (ghosty[i] - 12) && pacmany < (ghosty[i] + 12) &&
                ingame) {

                dying = true;
                deathcounter = 64;

            }
        }
    }

    public void DrawGhost(Graphics2D g2d, int x, int y) {
        g2d.drawImage(ghost, x, y, this);
    }

    public void MovePacMan() {
        int pos;
        short ch;

        if (reqdx == -pacmandx && reqdy == -pacmandy) {
            pacmandx = reqdx;
            pacmandy = reqdy;
            viewdx = pacmandx;
            viewdy = pacmandy;
        }
        if (pacmanx % blocksize == 0 && pacmany % blocksize == 0) {
            pos =
 pacmanx / blocksize + nrofblocks * (int)(pacmany / blocksize);
            ch = screendata[pos];

            if ((ch & 16) != 0) {
                screendata[pos] = (short)(ch & 15);
                score++;
            }

            if (reqdx != 0 || reqdy != 0) {
                if (!((reqdx == -1 && reqdy == 0 && (ch & 1) != 0) ||
                      (reqdx == 1 && reqdy == 0 && (ch & 4) != 0) ||
                      (reqdx == 0 && reqdy == -1 && (ch & 2) != 0) ||
                      (reqdx == 0 && reqdy == 1 && (ch & 8) != 0))) {
                    pacmandx = reqdx;
                    pacmandy = reqdy;
                    viewdx = pacmandx;
                    viewdy = pacmandy;
                }
            }

            // Check for standstill
            if ((pacmandx == -1 && pacmandy == 0 && (ch & 1) != 0) ||
                (pacmandx == 1 && pacmandy == 0 && (ch & 4) != 0) ||
                (pacmandx == 0 && pacmandy == -1 && (ch & 2) != 0) ||
                (pacmandx == 0 && pacmandy == 1 && (ch & 8) != 0)) {
                pacmandx = 0;
                pacmandy = 0;
            }
        }
        pacmanx = pacmanx + pacmanspeed * pacmandx;
        pacmany = pacmany + pacmanspeed * pacmandy;
    }

    public void DrawPacMan(Graphics2D g2d) {
        if (viewdx == -1)
            DrawPacManLeft(g2d);
        else if (viewdx == 1)
            DrawPacManRight(g2d);
        else if (viewdy == -1)
            DrawPacManUp(g2d);
        else
            DrawPacManDown(g2d);
    }

    public void DrawPacManUp(Graphics2D g2d) {
        switch (pacmananimpos) {
        case 1:
            g2d.drawImage(pacman2up, pacmanx + 1, pacmany + 1, this);
            break;
        case 2:
            g2d.drawImage(pacman3up, pacmanx + 1, pacmany + 1, this);
            break;
        case 3:
            g2d.drawImage(pacman4up, pacmanx + 1, pacmany + 1, this);
            break;
        default:
            g2d.drawImage(pacman1, pacmanx + 1, pacmany + 1, this);
            break;
        }
    }

    public void DrawPacManDown(Graphics2D g2d) {
        switch (pacmananimpos) {
        case 1:
            g2d.drawImage(pacman2down, pacmanx + 1, pacmany + 1, this);
            break;
        case 2:
            g2d.drawImage(pacman3down, pacmanx + 1, pacmany + 1, this);
            break;
        case 3:
            g2d.drawImage(pacman4down, pacmanx + 1, pacmany + 1, this);
            break;
        default:
            g2d.drawImage(pacman1, pacmanx + 1, pacmany + 1, this);
            break;
        }
    }

    public void DrawPacManLeft(Graphics2D g2d) {
        switch (pacmananimpos) {
        case 1:
            g2d.drawImage(pacman2left, pacmanx + 1, pacmany + 1, this);
            break;
        case 2:
            g2d.drawImage(pacman3left, pacmanx + 1, pacmany + 1, this);
            break;
        case 3:
            g2d.drawImage(pacman4left, pacmanx + 1, pacmany + 1, this);
            break;
        default:
            g2d.drawImage(pacman1, pacmanx + 1, pacmany + 1, this);
            break;
        }
    }

    public void DrawPacManRight(Graphics2D g2d) {
        switch (pacmananimpos) {
        case 1:
            g2d.drawImage(pacman2right, pacmanx + 1, pacmany + 1, this);
            break;
        case 2:
            g2d.drawImage(pacman3right, pacmanx + 1, pacmany + 1, this);
            break;
        case 3:
            g2d.drawImage(pacman4right, pacmanx + 1, pacmany + 1, this);
            break;
        default:
            g2d.drawImage(pacman1, pacmanx + 1, pacmany + 1, this);
            break;
        }
    }

    public void DrawMaze(Graphics2D g2d) {
        short i = 0;
        int x, y;

        for (y = 0; y < scrsize; y += blocksize) {
            for (x = 0; x < scrsize; x += blocksize) {
                g2d.setColor(mazecolor);
                g2d.setStroke(new BasicStroke(2));

                if ((screendata[i] & 1) != 0) // draws left
                {
                    g2d.drawLine(x, y, x, y + blocksize - 1);
                }
                if ((screendata[i] & 2) != 0) // draws top
                {
                    g2d.drawLine(x, y, x + blocksize - 1, y);
                }
                if ((screendata[i] & 4) != 0) // draws right
                {
                    g2d.drawLine(x + blocksize - 1, y, x + blocksize - 1,
                                 y + blocksize - 1);
                }
                if ((screendata[i] & 8) != 0) // draws bottom
                {
                    g2d.drawLine(x, y + blocksize - 1, x + blocksize - 1,
                                 y + blocksize - 1);
                }
                if ((screendata[i] & 16) != 0) // draws point
                {
                    g2d.setColor(dotcolor);
                    g2d.fillRect(x + 11, y + 11, 2, 2);
                }
                i++;
            }
        }
    }

    public void GameInit() {
        pacsleft = 3;
        score = 0;
        LevelInit();
        nrofghosts = 6;
        currentspeed = 3;
    }

    public void LevelInit() {
        int i;
        for (i = 0; i < nrofblocks * nrofblocks; i++)
            screendata[i] = leveldata[i];

        LevelContinue();
    }

    public void LevelContinue() {
        short i;
        int dx = 1;
        int random;

        for (i = 0; i < nrofghosts; i++) {
            ghosty[i] = 4 * blocksize;
            ghostx[i] = 4 * blocksize;
            ghostdy[i] = 0;
            ghostdx[i] = dx;
            dx = -dx;
            random = (int)(Math.random() * (currentspeed + 1));
            if (random > currentspeed)
                random = currentspeed;
            ghostspeed[i] = validspeeds[random];
        }

        pacmanx = 7 * blocksize;
        pacmany = 11 * blocksize;
        pacmandx = 0;
        pacmandy = 0;
        reqdx = 0;
        reqdy = 0;
        viewdx = -1;
        viewdy = 0;
        dying = false;
    }

    public void GetImages()
    {

      ghost = new ImageIcon(Board.class.getResource("../pacpix/ghost.png")).getImage();
      pacman1 = new ImageIcon(Board.class.getResource("../pacpix/pacman.png")).getImage();
      pacman2up = new ImageIcon(Board.class.getResource("../pacpix/up1.png")).getImage();
      pacman3up = new ImageIcon(Board.class.getResource("../pacpix/up2.png")).getImage();
      pacman4up = new ImageIcon(Board.class.getResource("../pacpix/up3.png")).getImage();
      pacman2down = new ImageIcon(Board.class.getResource("../pacpix/down1.png")).getImage();
      pacman3down = new ImageIcon(Board.class.getResource("../pacpix/down2.png")).getImage(); 
      pacman4down = new ImageIcon(Board.class.getResource("../pacpix/down3.png")).getImage();
      pacman2left = new ImageIcon(Board.class.getResource("../pacpix/left1.png")).getImage();
      pacman3left = new ImageIcon(Board.class.getResource("../pacpix/left2.png")).getImage();
      pacman4left = new ImageIcon(Board.class.getResource("../pacpix/left3.png")).getImage();
      pacman2right = new ImageIcon(Board.class.getResource("../pacpix/right1.png")).getImage();
      pacman3right = new ImageIcon(Board.class.getResource("../pacpix/right2.png")).getImage();
      pacman4right = new ImageIcon(Board.class.getResource("../pacpix/right3.png")).getImage();

    }

    public void paint(Graphics g)
    {
      super.paint(g);

      Graphics2D g2d = (Graphics2D) g;

      g2d.setColor(Color.black);
      g2d.fillRect(0, 0, d.width, d.height);

      DrawMaze(g2d);
      DrawScore(g2d);
      DoAnim();
      if (ingame)
        PlayGame(g2d);
      else
        ShowIntroScreen(g2d);

      g.drawImage(ii, 5, 5, this);
      Toolkit.getDefaultToolkit().sync();
      g.dispose();
    }

    class TAdapter extends KeyAdapter {
        public void keyPressed(KeyEvent e) {

          int key = e.getKeyCode();

          if (ingame)
          {
            if (key == KeyEvent.VK_LEFT)
            {
              reqdx=-1;
              reqdy=0;
            }
            else if (key == KeyEvent.VK_RIGHT)
            {
              reqdx=1;
              reqdy=0;
            }
            else if (key == KeyEvent.VK_UP)
            {
              reqdx=0;
              reqdy=-1;
            }
            else if (key == KeyEvent.VK_DOWN)
            {
              reqdx=0;
              reqdy=1;
            }
            else if (key == KeyEvent.VK_ESCAPE && timer.isRunning())
            {
              ingame=false;
            }
            else if (key == KeyEvent.VK_PAUSE) {
                if (timer.isRunning())
                    timer.stop();
                else timer.start();
            }
          }
          else
          {
            if (key == 's' || key == 'S')
          {
              ingame=true;
              GameInit();
            }
          }
      }

          public void keyReleased(KeyEvent e) {
              int key = e.getKeyCode();

              if (key == Event.LEFT || key == Event.RIGHT || 
                 key == Event.UP ||  key == Event.DOWN)
              {
                reqdx=0;
                reqdy=0;
              }
          }
      }

    public void actionPerformed(ActionEvent e) {
        repaint();  
    }
}

The Commons.java file has some common constants.

final short leveldata[] =
{ 19, 26, 26, 26, 18, ... };

These numbers make up the maze. They provide information out of which we create the corners and the points. For example number 19 in the upper left corner means, that the square will have top and left borders and a point. (16 + 2 + 1)

 public void doAnim() {
     pacanimcount--;
     if (pacanimcount <= 0) {
         pacanimcount = pacanimdelay;
         pacmananimpos = pacmananimpos + pacanimdir;
         if (pacmananimpos == (pacmananimcount - 1) || pacmananimpos == 0)
             pacanimdir = -pacanimdir;
     }
 }

The doAnim() counts the pacmananimpos variable, which determines what pacman image is drawn. There are four pacman images. There is also a pacanimdelay variable, which makes the animation a bit slower. Otherwise the pacman would open his mouth too fast.

boolean finished = true;

while (i < nrofblocks * nrofblocks && finished) {
    if ((screendata[i] & 16) != 0)
        finished = false;
    i++;
}

This code is part of the checkMaze() method. It checks, if there are any points left for the Pacman to eat. Number 16 stands for a point. If all points are consumed, we move to the next level.

Next we will examine the moveGhosts() method. The ghosts move one square and then decide, if they change the direction.

if (ghostx[i] % blocksize == 0 && ghosty[i] % blocksize == 0) {

Continue only if you have finished moving one square.

pos = ghostx[i] / blocksize + nrofblocks * (int)(ghosty[i] / blocksize);

This line determines, where the ghost is situated. In which position/square. There are 225 theoretical positions. (A ghost cannot move over walls. )

if ((screendata[pos] & 1) == 0 && ghostdx[i] != 1) {
    dx[count] = -1;
    dy[count] = 0;
    count++;
}

If there is no obstacle on the left and the ghost is not already moving to the right, the ghost will move to the left. What does this code really mean? If the ghost enters a tunnel, he will continue in the same direction until he is out of the tunnel. Moving of ghosts is partly random. We do not apply this randomness inside long tunnels. The ghost might get stuck there.

if (pacmanx > (ghostx[i] - 12) && pacmanx < (ghostx[i] + 12) &&
    pacmany > (ghosty[i] - 12) && pacmany < (ghosty[i] + 12) &&
    ingame) {

    dying = true;
    deathcounter = 64;
}

If there is a collision between ghosts and a pacman, the pacman dies.

Next we are going to examine the movePacman() method. The reqdx and reqdy variables are determined in the TAdapter inner class. These variables are controlled with cursor keys.

if ((ch & 16) != 0) {
    screendata[pos] = (short)(ch & 15);
    score++;
}

If the pacman moves to a position, where there is a point, we remove it from the maze and increase the score value.

if ((pacmandx == -1 && pacmandy == 0 && (ch & 1) != 0) ||
    (pacmandx == 1 && pacmandy == 0 && (ch & 4) != 0) ||
    (pacmandx == 0 && pacmandy == -1 && (ch & 2) != 0) ||
    (pacmandx == 0 && pacmandy == 1 && (ch & 8) != 0)) {
    pacmandx = 0;
    pacmandy = 0;
}

If the pacman cannot move further it his current direction, there is a standstill.

public void drawPacMan(Graphics2D g2d) {
    if (viewdx == -1)
        drawPacManLeft(g2d);
    else if (viewdx == 1)
        drawPacManRight(g2d);
    else if (viewdy == -1)
        drawPacManUp(g2d);
    else
        drawPacManDown(g2d);
}

There are four possible directions for a pacman. There are four images for all directions. The images are used to animate pacman opening a closing his mouth.

The drawMaze() method draws the maze out of the numbers in the screendata array. Number 1 is a left border, 2 is a top border, 4 is a right border, 8 is a bottom border and 16 is a point. We simply go through all 225 squares int the maze. For example we have 9 in the screendata array. We have the first bit (1) and the fourth bit (8) set. So we draw a bottom and a left border on this particular square.

if ((screendata[i] & 1) != 0) // draws left
{
    g2d.drawLine(x, y, x, y + blocksize - 1);
}

Draw a left border if the first bit of a number is set.

PacMan.java
package packman;

import javax.swing.JFrame;

import pacman.Board;

public class PacMan extends JFrame
{

  public PacMan()
  {
    add(new Board());
    setTitle("Pacman");
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setSize(380, 420);
    setLocationRelativeTo(null);
    setVisible(true);
  }  public static void main(String[] args) {
      new PacMan();
  }
}

This is a PacMan file with a main method.

Pacman

Figure: Pacman

This was the Pacman game.

 

In this part of the Java 2D games tutorial, we will create a Java Snake game clone.

Snake

Snake is an older classic video game. It was first created in late 70s. Later it was brought to PCs. In this game the player controls a snake. The objective is to eat as many apples as possible. Each time the snake eats an apple, its body grows. The snake must avoid the walls and its own body. This game is sometimes called Nibbles.

Development

The size of each of the joints of a snake is 10px. The snake is controlled with the cursor keys. Initially the snake has three joints. The game is started by pressing one of the cursor keys. If the game is finished, we display Game Over message in the middle of the Board.

Board.java
package snake2;

import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.Timer;

public class Board extends JPanel implements ActionListener {

    private final int WIDTH = 300;
    private final int HEIGHT = 300;
    private final int DOT_SIZE = 10;
    private final int ALL_DOTS = 900;
    private final int RAND_POS = 29;
    private final int DELAY = 140;

    private int x[] = new int[ALL_DOTS];
    private int y[] = new int[ALL_DOTS];

    private int dots;
    private int apple_x;
    private int apple_y;

    private boolean left = false;
    private boolean right = true;
    private boolean up = false;
    private boolean down = false;
    private boolean inGame = true;

    private Timer timer;
    private Image ball;
    private Image apple;
    private Image head;

    public Board() {
        addKeyListener(new TAdapter());

        setBackground(Color.black);

        ImageIcon iid = new ImageIcon(this.getClass().getResource("dot.png"));
        ball = iid.getImage();

        ImageIcon iia = new ImageIcon(this.getClass().getResource("apple.png"));
        apple = iia.getImage();

        ImageIcon iih = new ImageIcon(this.getClass().getResource("head.png"));
        head = iih.getImage();

        setFocusable(true);
        initGame();
    }

    public void initGame() {

        dots = 3;

        for (int z = 0; z < dots; z++) {
            x[z] = 50 - z*10;
            y[z] = 50;
        }

        locateApple();

        timer = new Timer(DELAY, this);
        timer.start();
    }

    public void paint(Graphics g) {
        super.paint(g);

        if (inGame) {

            g.drawImage(apple, apple_x, apple_y, this);

            for (int z = 0; z < dots; z++) {
                if (z == 0)
                    g.drawImage(head, x[z], y[z], this);
                else g.drawImage(ball, x[z], y[z], this);
            }

            Toolkit.getDefaultToolkit().sync();
            g.dispose();

        } else {
            gameOver(g);
        }
    }

    public void gameOver(Graphics g) {
        String msg = "Game Over";
        Font small = new Font("Helvetica", Font.BOLD, 14);
        FontMetrics metr = this.getFontMetrics(small);

        g.setColor(Color.white);
        g.setFont(small);
        g.drawString(msg, (WIDTH - metr.stringWidth(msg)) / 2,
                     HEIGHT / 2);
    }

    public void checkApple() {

        if ((x[0] == apple_x) && (y[0] == apple_y)) {
            dots++;
            locateApple();
        }
    }

    public void move() {

        for (int z = dots; z > 0; z--) {
            x[z] = x[(z - 1)];
            y[z] = y[(z - 1)];
        }

        if (left) {
            x[0] -= DOT_SIZE;
        }

        if (right) {
            x[0] += DOT_SIZE;
        }

        if (up) {
            y[0] -= DOT_SIZE;
        }

        if (down) {
            y[0] += DOT_SIZE;
        }
    }

    public void checkCollision() {

          for (int z = dots; z > 0; z--) {

              if ((z > 4) && (x[0] == x[z]) && (y[0] == y[z])) {
                  inGame = false;
              }
          }

        if (y[0] > HEIGHT) {
            inGame = false;
        }

        if (y[0] < 0) {
            inGame = false;
        }

        if (x[0] > WIDTH) {
            inGame = false;
        }

        if (x[0] < 0) {
            inGame = false;
        }
    }

    public void locateApple() {
        int r = (int) (Math.random() * RAND_POS);
        apple_x = ((r * DOT_SIZE));
        r = (int) (Math.random() * RAND_POS);
        apple_y = ((r * DOT_SIZE));
    }

    public void actionPerformed(ActionEvent e) {

        if (inGame) {
            checkApple();
            checkCollision();
            move();
        }

        repaint();
    }

    private class TAdapter extends KeyAdapter {

        public void keyPressed(KeyEvent e) {

            int key = e.getKeyCode();

            if ((key == KeyEvent.VK_LEFT) && (!right)) {
                left = true;
                up = false;
                down = false;
            }

            if ((key == KeyEvent.VK_RIGHT) && (!left)) {
                right = true;
                up = false;
                down = false;
            }

            if ((key == KeyEvent.VK_UP) && (!down)) {
                up = true;
                right = false;
                left = false;
            }

            if ((key == KeyEvent.VK_DOWN) && (!up)) {
                down = true;
                right = false;
                left = false;
            }
        }
    }
}

First we will define the constants used in our game.

private final int WIDTH = 300;
private final int HEIGHT = 300;
private final int DOT_SIZE = 10;
private final int ALL_DOTS = 900;
private final int RAND_POS = 29;
private final int DELAY = 140;

The WIDTH and HEIGHT constants determine the size of the Board. The DOT_SIZE is the size of the apple and the dot of the snake. The ALL_DOTS constant defines the maximum number of possible dots on the Board. (900 = 300*300/10*10) The RAND_POS constant is used to calculate a random position of an apple. The DELAY constant determines the speed of the game.

private int x[] = new int[ALL_DOTS];
private int y[] = new int[ALL_DOTS];

These two arrays store x, y coordinates of all joints of a snake.

In the move() method we have the key algorithm of the game. To understand it, look at how the snake is moving. You control the head of the snake. You can change its direction with the cursor keys. The rest of the joints move one position up the chain. The second joint moves where the first was, the third joint where the second was etc.

 for (int z = dots; z > 0; z--) {
     x[z] = x[(z - 1)];
     y[z] = y[(z - 1)];
 }

This code moves the joints up the chain.

if (left) {
    x[0] -= DOT_SIZE;
}

Move the head to the left.

In the checkCollision() method, we determine if the snake has hit itself or one of the walls.

for (int z = dots; z > 0; z--) {

    if ((z > 4) && (x[0] == x[z]) && (y[0] == y[z])) {
        inGame = false;
    }
}

Finish the game, if the snake hits one of its joints with the head.

if (y[0] > HEIGHT) {
    inGame = false;
}

Finish the game, if the snake hits the bottom of the Board.

Snake.java
package snake2;

import javax.swing.JFrame;

public class Snake extends JFrame {

    public Snake() {

        add(new Board());

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(320, 340);
        setLocationRelativeTo(null);
        setTitle("Snake");

        setResizable(false);
        setVisible(true);
    }    public static void main(String[] args) {
        new Snake();
    }
}

This is the main class.

Snake

Figure: Snake

This was the Snake game.

 

MySQL

Stop all services in wamp.

Then make changes to php.ini

post_max_size = 750M
upload_max_filesize = 750M
max_execution_time = 5000
max_input_time = 5000
memory_limit = 1000M
max_allowed_packet = 200M (in mysql  my.ini  file)

Restart all services and it should be okay,

Now  XXXMb file upload very quickly.