/**
* Removes an {@code Actor} from the {@code World}. The {@code Actor} must be both bound to this
* {@code World} and not held by another {@code Actor}. However, if the {@code Actor} is expired,
* it may always be removed.
*
* @param actor the {@code Actor} to be removed
*/
public void removeActor(Actor actor) {
Guard.argumentIsNotNull(actor);
Guard.verifyState(actor.bound(this));
Guard.verifyState(!actor.held() || actor.expired());
unregisterActor(actor);
removeFromGrid(actor);
actor.setWorld(null);
}
/**
* Adds an {@code Actor} to the {@code World} at the specified location.
*
* @param actor the {@code World} being added
* @param x the x location of the {@code Actor}
* @param y the y location of the {@code Actor}
*/
public void addActor(Actor actor, int x, int y) {
Guard.argumentIsNotNull(actor);
Guard.argumentsInsideBounds(x, y, width, height);
Guard.verifyState(!actor.bound());
Guard.verifyState(!actor.held());
actor.setWorld(this);
actor.setXY(x, y);
addToGrid(actor);
registerActor(actor);
}
/**
* Returns the probability of the specified value given a particular {@code Categorical}.
*
* @param key the key of the {@code Categorical} being queried
* @param value the value being queried
* @return the probability of value given the key
*/
public double probabilityGiven(K key, V value) {
Guard.verifyState(totals.sumCounts() > 0);
return sumCountGiven(key) > 0 ? getCategorical(key).probability(value) : 0;
}