Package org.bitbrawl.foodfight.util

Class PlayerUtils

java.lang.Object

org.bitbrawl.foodfight.util.PlayerUtils

@Immutable
public final class PlayerUtils
extends Object

A utility class to get information about players on the field.

Author:

Finn

Method Summary

Modifier and Type	Method	Description
static boolean	canPickup(Player player, Food food, Player.Hand hand)	Determines whether the given player can pick up the given food piece, with the given hand.
static Direction	getArmDirection(Player player, Player.Hand hand)	Gets the direction of a player's arm.
static Vector	getArmLocation(Player player, Player.Hand hand)	Gets the location of the player's arm.
static double	getMoveMultiplier(double energy)	Gets the multiplier for a player's movement, based on their energy.
static boolean	isAgainstTable(Player player, Table table, boolean movingForward)	Determines whether the given player is against the table.
static boolean	isValidAction(Field field, Player player, Controller.Action action)	Determines whether the given action is currently valid for the given player.

Methods inherited from class java.lang.Object

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

Method Detail

isValidAction

public static boolean isValidAction(Field field,
                                    Player player,
                                    Controller.Action action)

Determines whether the given action is currently valid for the given player.

There is one special case in which the result of this method can be misleading. If two players attempt to pick up the same food on the same turn, turn order is randomized, so one of them will be able to grab it and the other won't. Thus, if a controller returns one of the "pickup" actions because this method returns true, it may actually end up being an invalid action if another player picks up the food.

Parameters:

field - the field that the player is playing on

player - the player on the field potentially performing the action

action - the action in question

Returns:

true if the player can play the action, otherwise false

Throws:

NullPointerException - if field or player is null

canPickup

public static boolean canPickup(Player player,
                                Food food,
                                Player.Hand hand)

Determines whether the given player can pick up the given food piece, with the given hand. This is true if the food piece is on the ground and "in range" of the player. A player's range is defined by a sector, centered on the player's center, with a radius of Player.REACH_DISTANCE and an angle measurement of Player.REACH_RANGE, centered on the direction returned by getArmDirection(Player, Hand).

Parameters:

player - the player attempting a "pickup" action

food - the food that the player may pick up

hand - the hand with which the player is attempting the pickup

Returns:

true if the player can pick up the food, otherwise false

Throws:

NullPointerException - if player, food, or hand is null

isAgainstTable

public static boolean isAgainstTable(Player player,
                                     Table table,
                                     boolean movingForward)

Determines whether the given player is against the table. The movingForward parameter refers to the player's direction of travel. If movingForward is true, then the player must be facing toward the table for this method to return true. If movingForward is false, then the player must be facing away from the table for this method to return true. In other words, if movingForward is true, this method returns true if and only if the table would prevent the player from performing an Controller.Action.MOVE_FORWARD, and if movingForward is false, this method returns true if and only if the table would prevent the player from performing and Controller.Action.MOVE_BACKWARD.

Parameters:

player - the player in question

table - the table that the player may be against

movingForward - true if the player is moving forward, false if backward

Returns:

true if the player would be impeded by the table, otherwise false

Throws:

NullPointerException - if player or table is null

getArmDirection

public static final Direction getArmDirection(Player player,
                                              Player.Hand hand)

Gets the direction of a player's arm. Equivalently, this is the player's heading, added to either Player.LEFT_ARM_DIRECTION or Player.RIGHT_ARM_DIRECTION. The arm direction of a player is used to determine where they can pickup food (see canPickup(Player, Food, Hand)) and where thrown food is spawened (see getArmLocation(Player, Hand)).

Parameters:

player - the player in question

hand - the side of the player to check

Returns:

the direction of that player's arm

Throws:

NullPointerException - if player or hand is null

getArmLocation

public static final Vector getArmLocation(Player player,
                                          Player.Hand hand)

Gets the location of the player's arm. This is the location that is Player.REACH_DISTANCE away from the player's center, in the direction of getArmDirection(Player, Hand). Equivalently, this is the location at which thrown food is spawned.

Parameters:

player - the player whose arm to check

hand - the side of the player to check

Returns:

the location at which thrown food would be spawned

Throws:

NullPointerException - if player or hand is null

getMoveMultiplier

public static double getMoveMultiplier(double energy)

Gets the multiplier for a player's movement, based on their energy. Whenever a player moves, the distance traveled will be multiplied by the result of this function. The answer is equivalent to e^{energy / Player.MAX_ENERGY - 1}

Parameters:

energy - the player's energy

Returns:

the factor used to calculate the player's travel distance.