Package model

Class GameModel

java.lang.Object

model.GameModel

public class GameModel
extends Object

The underlying state representation of a PacMann game, including the game graph and actors.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	GameModel.GameState	During its lifetime, the game transitions from READY -> PLAYING -> either VICTORY/DEFEAT
static enum	GameModel.Item	Each path tile contains a dot, contains a pellet, or is empty.
private static class	GameModel.PacMannCaught	Indicates that a collision between PacMann and a CHASING ghost was detected, meaning that the current round should end.
private static final record	GameModel.Trajectory	The position and velocity of an actor on an associated _undirected_ edge.
private static final class	GameModel.UnorderedPair<T>	An unordered pair of values of type `T`.

Field Summary

Fields

Modifier and Type	Field	Description
private final List<Actor>	actors	The actors in this game, PacMann will be in index 0 and the ghosts will be in indices 1-4
private final MazeGraph	graph	The graph representation of the game's maze
private final int	height	The number of cells tall the maze is
private final Map<MazeGraph.MazeVertex,GameModel.Item>	items	A map from the vertices in the game graph to items positioned on these vertices.
private final GameMap	map	The map associated with this model
private int	numGhostsCaught	The number of ghosts that were caught during the current FLEE cycle
private int	numLives	The number of lives remaining
protected SwingPropertyChangeSupport	propSupport	Helper object for managing property change notifications.
private int	score	The current score
private GameModel.GameState	state	The current state of this model
private double	time	The amount of time that has elapsed
private final int	width	The number of cells across the maze is

Constructor Summary

Constructors

Constructor	Description
GameModel(GameMap map, Randomness randomness, boolean withAI)	Construct a new game model using the given arrays of tile types and elevations

Method Summary

Modifier and Type	Method	Description
Iterable<Actor>	actors()	Return the actors associated with this game instance
void	addPropertyChangeListener(String propertyName, PropertyChangeListener listener)	Register `listener` to be notified whenever the property named `propertyName` of this model is changed.
private void	addToScore(int points)	Increment the current score by `points` points and notify "score" observers.
Ghost	blinky()	Return a reference to this game instance's Blinky Actor object
Ghost	clyde()	Return a reference to this game instance's Clyde Actor object
private void	collideWithGhost(Ghost g)	Handle a PacMann-Ghost collision.
private void	defeat()	Handle the end of the round (i.e., when PacMann has been caught).
MazeGraph	graph()	Return a reference to this game's graph
int	height()	Return the height of the maze in this game instance
Ghost	inky()	Return a reference to this game instance's Inky Actor object
GameModel.Item	itemAt(MazeGraph.MazeVertex v)	Return the item located at the given Vertex `v`, possibly NONE.
GameMap	map()	Return the GameMap that was used to construct this model
private void	navAndGuide()	Give any actor currently standing on a vertex an opportunity to decide which edge to traverse next.
static GameModel	newGame(int width, int height, boolean withAI, Randomness randomness)	Static method to construct a GameModel object associated with a new random maze
private double	nextCollisionTime()	Return the earliest timestep at which two actors will collide, given their current trajectories.
private double	nextDt(double maxDt)	Return the largest timestep that the engine can propagate the actors by, up to `maxDt`.
int	numLives()	Return the number of remaining lives
PacMann	pacMann()	Return a reference to this game instance's PacMann Actor object
Ghost	pinky()	Return a reference to this game instance's Pinky Actor object
private void	placeDotsAndPellets()	Adds all dots and pellets to `items` during the construction of this game.
private void	processCollision(Actor a1, Actor a2)	Handle a collision detected between two actors.
void	processPacMannArrival()	Update the model to reflect PacMann's arrival at a vertex.
void	removePropertyChangeListener(String propertyName, PropertyChangeListener listener)	Stop notifying `listener` of changes to the property named `propertyName` for this model (assuming it was added no more than once).
void	resetActors()	Resets all ghosts to their WAIT state and PacMann to his starting position, then transitions to the READY state.
int	score()	Return the current score
private void	setState(GameModel.GameState newState)	Transition to `newState` and notify observers.
private void	startFlee()	Initiate the FLEE sequence by resetting the number of caught ghosts and transitioning all non-WAITING ghosts to their FLEE state.
GameModel.GameState	state()	Return the current state of this game.
double	time()	Return the amount of elapsed time
void	updateActors(double totalDt)	Propagate the game forward in time by `totalDt` ms.
void	useLife()	Decrease the number of remaining lives by one, notifying "lives" observers.
private void	victory()	Handle a victorious end of the game (i.e., when PacMann has eaten all of the dots and pellets).
int	width()	Return the width of the maze in this game instance

Methods inherited from class java.lang.Object

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

Field Details

state

private GameModel.GameState state

The current state of this model

map

private final GameMap map

The map associated with this model

items

private final Map<MazeGraph.MazeVertex,GameModel.Item> items

A map from the vertices in the game graph to items positioned on these vertices. `item` only includes the vertices containing DOTs and PELLETs, not NONE.

graph

private final MazeGraph graph

The graph representation of the game's maze

score

private int score

The current score

time

private double time

The amount of time that has elapsed

width

private final int width

The number of cells across the maze is

height

private final int height

The number of cells tall the maze is

actors

private final List<Actor> actors

The actors in this game, PacMann will be in index 0 and the ghosts will be in indices 1-4

numGhostsCaught

private int numGhostsCaught

The number of ghosts that were caught during the current FLEE cycle

numLives

private int numLives

The number of lives remaining

propSupport

protected SwingPropertyChangeSupport propSupport

Helper object for managing property change notifications.

Constructor Details

GameModel

public GameModel(GameMap map,
 Randomness randomness,
 boolean withAI)

Construct a new game model using the given arrays of tile types and elevations

Method Details

newGame

public static GameModel newGame(int width,
 int height,
 boolean withAI,
 Randomness randomness)

Static method to construct a GameModel object associated with a new random maze

placeDotsAndPellets

private void placeDotsAndPellets()

Adds all dots and pellets to `items` during the construction of this game.

map

public GameMap map()

Return the GameMap that was used to construct this model

width

public int width()

Return the width of the maze in this game instance

height

public int height()

Return the height of the maze in this game instance

graph

public MazeGraph graph()

Return a reference to this game's graph

actors

public Iterable<Actor> actors()

Return the actors associated with this game instance

pacMann

public PacMann pacMann()

Return a reference to this game instance's PacMann Actor object

blinky

public Ghost blinky()

Return a reference to this game instance's Blinky Actor object

pinky

public Ghost pinky()

Return a reference to this game instance's Pinky Actor object

inky

public Ghost inky()

Return a reference to this game instance's Inky Actor object

clyde

public Ghost clyde()

Return a reference to this game instance's Clyde Actor object

score

public int score()

Return the current score

time

public double time()

Return the amount of elapsed time

itemAt

public GameModel.Item itemAt(MazeGraph.MazeVertex v)

Return the item located at the given Vertex `v`, possibly NONE. This method will never return null.

state

public GameModel.GameState state()

Return the current state of this game.

numLives

public int numLives()

Return the number of remaining lives

addToScore

private void addToScore(int points)

Increment the current score by `points` points and notify "score" observers.

startFlee

private void startFlee()

Initiate the FLEE sequence by resetting the number of caught ghosts and transitioning all non-WAITING ghosts to their FLEE state.

processPacMannArrival

public void processPacMannArrival()

Update the model to reflect PacMann's arrival at a vertex.

setState

private void setState(GameModel.GameState newState)

Transition to `newState` and notify observers.

resetActors

public void resetActors()

Resets all ghosts to their WAIT state and PacMann to his starting position, then transitions to the READY state.

useLife

public void useLife()

Decrease the number of remaining lives by one, notifying "lives" observers.

defeat

private void defeat()

Handle the end of the round (i.e., when PacMann has been caught). Consume a life and reset if at least one life still remains. Otherwise, transition to the DEFEAT state and notify "game_result" observers.

victory

private void victory()

Handle a victorious end of the game (i.e., when PacMann has eaten all of the dots and pellets). Transition to the VICTORY state and notify "game_result" observers.

addPropertyChangeListener

public void addPropertyChangeListener(String propertyName,
 PropertyChangeListener listener)

Register `listener` to be notified whenever the property named `propertyName` of this model is changed.

removePropertyChangeListener

public void removePropertyChangeListener(String propertyName,
 PropertyChangeListener listener)

Stop notifying `listener` of changes to the property named `propertyName` for this model (assuming it was added no more than once). Does not affect listeners who were not registered with `propertyName`.

processCollision

private void processCollision(Actor a1,
 Actor a2)
                       throws GameModel.PacMannCaught

Handle a collision detected between two actors.

Throws:

GameModel.PacMannCaught

collideWithGhost

private void collideWithGhost(Ghost g)
                       throws GameModel.PacMannCaught

Handle a PacMann-Ghost collision. Score and respawn ghosts if they are fleeing; otherwise, throw `PacMannCaught`. Fleeing ghosts earn points exponential in the number of ghosts caught since the last pellet was consumed.

Throws:

GameModel.PacMannCaught

updateActors

public void updateActors(double totalDt)

Propagate the game forward in time by `totalDt` ms. Process all actor collisions and vertex visitations. Update actors' traversed edges upon reaching a vertex. Handle round-end and game-end conditions, notifying observers. Notify "board_state" observers after propagation has concluded.

navAndGuide

private void navAndGuide()

Give any actor currently standing on a vertex an opportunity to decide which edge to traverse next. Enforces that their next edge starts at their current location.

nextDt

private double nextDt(double maxDt)

Return the largest timestep that the engine can propagate the actors by, up to `maxDt`. Timestep is constrained by actor vertex arrivals, actor state changes, and actor collisions. A minimum timestep is imposed to ensure forward progress.

nextCollisionTime

private double nextCollisionTime()

Return the earliest timestep at which two actors will collide, given their current trajectories. Actors may cross each other along an edge or may meet at a vertex. Returns POSITIVE_INFINITY if no actors will collide along their current edge trajectories.