Class InvadersWorld

java.lang.Object
  World
      InvadersWorld

public class InvadersWorld
extends World

InvadersWorld: A styled and fun Space Invaders clone. Special feature: multiplayer mode: two humans can play with one keyboard, sending waves of spaceships into battle against each other.

Field Summary

protected static int	BAR_HEIGHT Health bars' height.
protected static int	BAR_WIDTH Health bars' width.
static int	BLACK
protected HealthBar	blackBar
int[]	chance Array[N_SIDES]: Denominator for probability P for spaceship creation.
int[]	coll_chance Array[N_SIDES]: Denominator for probability P for collectible creation.
protected CollectibleFactory[]	collFactory
protected java.util.ArrayList	destroyList List containing objects that need destruction at the start of the next turn.
protected static int	DISTANCE Distance of health bars to game field edges.
protected SpaceshipFactory[]	factory
protected static int	HEIGHT Game field height.
protected static boolean	MULTIPLAYER Magic variable altering the game's behavior.
static int	N_SIDES Number of sides participating in the game.
protected int	next_turn_winner if it is clear that one side wins or loses (within a Greenfoot turn), this variable is set to the side of the winner.
boolean[]	player Array[N_SIDES]: true if the corresponding side is a human player, false if they're AI.
boolean[]	player_generates_spaceships Array[N_SIDES]: true if the corresponding side should generate & send out autonomous spaceships.
protected static int	STARTING_ZONE Size of the zone at the upper and lower edge of the playfield where new spaceships can be created.
static int	WHITE
protected HealthBar	whiteBar
protected static int	WIDTH Game field width.

Constructor Summary

InvadersWorld()

InvadersWorld(int worldWidth, int worldHeight, int cellSize)
InvadersWorld constructor.

Method Summary

void	act() Actions that a world just has to perform.
void	addObjectToDestroy(QuantumObject obj)
void	createCollectible(int x, int y, int c_side) Uses the side's collectible factory to get a random collectible.
void	gameOver(int winner) Called when the game is totally over, this method displays an end screen.
void	gameOverNextTurn(int winner)
void	maybeCreateCollectible(int x, int y, int c_side) Usually called by dying spaceships, this rolls a dice and maybe creates a collectible at that very place.
void	setHealthBar(int side, int value)
void	setHealthBar(int side, int value, int max_value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MULTIPLAYER

protected static final boolean MULTIPLAYER

Magic variable altering the game's behavior. If set to true, multi-player mode is enabled!

See Also:

Constant Field Values

WIDTH

protected static final int WIDTH

Game field width.

See Also:

Constant Field Values

HEIGHT

protected static final int HEIGHT

Game field height.

See Also:

Constant Field Values

BAR_WIDTH

protected static final int BAR_WIDTH

Health bars' width.

See Also:

Constant Field Values

BAR_HEIGHT

protected static final int BAR_HEIGHT

Health bars' height.

See Also:

Constant Field Values

DISTANCE

protected static final int DISTANCE

Distance of health bars to game field edges.

See Also:

Constant Field Values

STARTING_ZONE

protected static final int STARTING_ZONE

Size of the zone at the upper and lower edge of the playfield where new spaceships can be created.

See Also:

Constant Field Values

WHITE

public static final int WHITE

See Also:

Constant Field Values

BLACK

public static final int BLACK

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Constant Field Values

N_SIDES

public static final int N_SIDES

Number of sides participating in the game. Usually 2, still written as a constant for clearer code.

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Constant Field Values

factory

protected SpaceshipFactory[] factory

collFactory

protected CollectibleFactory[] collFactory

player

public boolean[] player

Array[N_SIDES]: true if the corresponding side is a human player, false if they're AI.

player_generates_spaceships

public boolean[] player_generates_spaceships

Array[N_SIDES]: true if the corresponding side should generate & send out autonomous spaceships. Usually true for the computer enemy or for both sides in 2-player mode.

See Also:

act()

chance

public int[] chance

Array[N_SIDES]: Denominator for probability P for spaceship creation. I. e., chance for a spaceship being generated each turn is 1/chance[side].

See Also:

act()

coll_chance

public int[] coll_chance

Array[N_SIDES]: Denominator for probability P for collectible creation. I. e., chance for a collectible being generated for each destroyed spaceship is 1/coll_chance[side].

See Also:

maybeCreateCollectible(int x, int y, int c_side), createCollectible(int x, int y, int c_side)

destroyList

protected java.util.ArrayList destroyList

List containing objects that need destruction at the start of the next turn. (Currently unused, if I am informed correctly.)

blackBar

protected HealthBar blackBar

whiteBar

protected HealthBar whiteBar

next_turn_winner

protected int next_turn_winner

if it is clear that one side wins or loses (within a Greenfoot turn), this variable is set to the side of the winner. InvadersWorld.act() will act thereafter.

See Also:

act()

Constructor Detail

InvadersWorld

public InvadersWorld()

InvadersWorld

public InvadersWorld(int worldWidth,
                     int worldHeight,
                     int cellSize)

InvadersWorld constructor. Creates and initializes all objects that are necessary for gameplay. The section that creates the two manually controlled spaceships might be of special interest. They're marked in the source code.

Method Detail

setHealthBar

public void setHealthBar(int side,
                         int value)

setHealthBar

public void setHealthBar(int side,
                         int value,
                         int max_value)

act

public void act()

Actions that a world just has to perform. Main things: 1. Create random spaceships. 2. Delete objects in the deletion list. 3. End the game if necessary. TODO: Increase difficulty (i. e. ship levels, probabilities) over time.

maybeCreateCollectible

public void maybeCreateCollectible(int x,
                                   int y,
                                   int c_side)

Usually called by dying spaceships, this rolls a dice and maybe creates a collectible at that very place.

createCollectible

public void createCollectible(int x,
                              int y,
                              int c_side)

Uses the side's collectible factory to get a random collectible.

See Also:

CollectibleFactory

addObjectToDestroy

public void addObjectToDestroy(QuantumObject obj)

gameOverNextTurn

public void gameOverNextTurn(int winner)

gameOver

public void gameOver(int winner)

Called when the game is totally over, this method displays an end screen. TODO: scoring.