stream.alwaysbecrafting.flare

Class EntitySystem

java.lang.Object

stream.alwaysbecrafting.flare.GameSystem

stream.alwaysbecrafting.flare.EntitySystem

All Implemented Interfaces:

java.lang.Comparable<GameSystem>

public abstract class EntitySystem
extends GameSystem

Specialized GameSystem that handles a set of Entities matching some constraints

At some point before being added to a GameEngine (usually in the constructor), a subclass of this class should call one or more of requireAll(Class[]), requireOne(Class[]), or forbid(Class[]) to describe which Entities should be given to its onHandleEntity(Entity, float) method.

After the system is added, onHandleEntity(Entity, float) will be called each game loop for every Entity that matches the given constraints.

Constructor Summary

Constructors

Constructor and Description
EntitySystem()

Method Summary

Modifier and Type	Method and Description
protected void	forbid(java.lang.Class<?>... componentTypes) Supply a list of components that must not be present in entities that will be handled by this system
protected abstract void	onHandleEntity(Entity entity, float deltaTime) Override to do something with the entities that match this system's filter parameters
void	onUpdate(GameEngine engine, float deltaTime) Called when this system should execute its main game loop behavior.
protected void	requireAll(java.lang.Class<?>... componentTypes) Supply a list of components that must all be present in entities that will be handled by this system
protected void	requireOne(java.lang.Class<?>... componentTypes) Supply a list of components from which at least one must be present in entities that will be handled by this system

Methods inherited from class stream.alwaysbecrafting.flare.GameSystem

compareTo, onPause, onResume, onStart, onStop, pause, resume

Methods inherited from class java.lang.Object

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

Constructor Detail

EntitySystem

public EntitySystem()

Method Detail

onUpdate

public void onUpdate(GameEngine engine,
                     float deltaTime)

Description copied from class: GameSystem

Called when this system should execute its main game loop behavior. This is where the system will do most of its work, and is called once for each time GameEngine.update(float) is called on the attached GameEngine.

Overrides:

onUpdate in class GameSystem

Parameters:

engine - The engine this update is occurring in

deltaTime - The time given to GameEngine.update(float) for this iteration of the game loop; ostensibly, the time between the previous loop and the current one

requireAll

protected void requireAll(java.lang.Class<?>... componentTypes)

Supply a list of components that must all be present in entities that will be handled by this system

A good place to call this is in a constructor

Parameters:

componentTypes - The components to include

requireOne

protected void requireOne(java.lang.Class<?>... componentTypes)

Supply a list of components from which at least one must be present in entities that will be handled by this system

May only be called before the system is added to a GameEngine, and may not be called more than once

A good place to call this is in a constructor

Parameters:

componentTypes - The components to include

Throws:

java.lang.IllegalStateException - If requireOne() has been called before, or if this system is already added to an engine

forbid

protected void forbid(java.lang.Class<?>... componentTypes)

Supply a list of components that must not be present in entities that will be handled by this system

May only be called before the system is added to a GameEngine, and may not be called more than once

A good place to call this is in a constructor

Parameters:

componentTypes - The components to exclude

Throws:

java.lang.IllegalStateException - If forbid() has been called before, or if this system is already added to an engine

onHandleEntity

protected abstract void onHandleEntity(Entity entity,
                                       float deltaTime)

Override to do something with the entities that match this system's filter parameters

Parameters:

entity - A matching Entity

deltaTime - The time given to GameEngine.update(float) for this iteration of the game loop; ostensibly, the time between the previous loop and the current one