/** Adds the {@link EntitySystem} to this Engine. */
public void addSystem(EntitySystem system) {
Class<? extends EntitySystem> systemType = system.getClass();
if (!systemsByClass.containsKey(systemType)) {
systems.add(system);
systemsByClass.put(systemType, system);
system.addedToEngine(this);
systems.sort(comparator);
}
}
/** Removes the {@link EntitySystem} from this Engine. */
public void removeSystem(EntitySystem system) {
if (systems.removeValue(system, true)) {
systemsByClass.remove(system.getClass());
system.removedFromEngine(this);
}
}