Introducing your Game EnginePart 1

Games Fundamentals© by Jarek Francik

Kingston University, London

February 2008

KU Games Fundamental Classes

• A skeleton for:– a windowed application– full-screen application– applet

• Organising your animation loop– drawing your screen– updating your screen

• Providing Sprites

KU GFC Library Structure

• Package: kingston.gamefx– class: Game– class: GamePanel– class: GameWinApp– class: GameApplet– class: GameGraphics

• Package: kingston.sprite– class: Sprite

• subclasses: RectSprite, CircleSprite, BitmapSprite

– class: SpriteList

Structure of a Windowed Game

Game

GameWinAppGamePanel

Structure of a Windowed Game

• GameWinApp – creates Game Windowyou just need to create an instance

• GamePanel – displays and controls the gamea game panel is created automaticallyand you'll rarely use this class directly

• Game – the Game Enginethat's what's you're going to do:develop a Game-derived class to implementyour very own class

A Windowed Game – what to do?

• Develop your Game Class

• Add your main function to:– Create an instance of your Game Class– Create an instance of GameWinApp– Start your game

A Windowed Game – what to do?

public static void main(String[] args)

{

Game game = new MazeGame(800, 600);

GameWinApp app = new GameWinApp();

app.openWindow("Crazy Maze", game);

}

Full Screen Games

• GameWinApp objects can run them, too!

• to open a windowed game:

app.openWindow("Crazy Maze", game)

• to open a full-screen game:

app.openFullScreen(game)

Full Screen Games

final static boolean bFullScreen = false;

public static void main(String[] args) {Game game = new MazeGame(800, 600);GameWinApp app = new GameWinApp();if (bFullScreen)

app.openFullScreen(game);else

app.openWindow("Crazy Maze", game);}

Applets

• GameApplet class derived from JApplet, standard java applet class

• Every applet class must be initialised

1. Create a GameApplet derived class

2. Write a simple init() method

Applets

public final class Maze extends GameApplet { // mandatory... private static final long serialVersionUID = 1;

// Applet Initialisation goes here...public void init(){

setGame(new MazeGame(800, 600));super.init();

}}

Universal Games

• Combine them both:– create a regular Applet class– add the main method for the windowed game

package kingston.games.maze;

import kingston.gamefx.Game;import kingston.gamefx.GameApplet;import kingston.gamefx.GameWinApp;

public final class Maze extends GameApplet {

private static final long serialVersionUID = 1; final static boolean bFullScreen = false;

// Applet Initialisation goes here...public void init(){

setGame(new MazeGame(800, 600));super.init();

}

public static void main(String[] args) {

Game game = new MazeGame(800, 600);GameWinApp app = new GameWinApp();if (bFullScreen)

app.openFullScreen(game);else

app.openWindow("Crazy Maze", game);}

}