/**
* Converts coordinates for this group to those of a descendant actor. The descendant does not
* need to be a direct child.
*
* @throws IllegalArgumentException if the specified actor is not a descendant of this group.
*/
public void localToDescendantCoordinates(Actor descendant, Vector2 localPoint) {
Group parent = descendant.getParent();
if (parent == null)
throw new IllegalArgumentException("Child is not a descendant: " + descendant);
// First convert to the actor's parent coordinates.
if (parent != this) localToDescendantCoordinates(parent, localPoint);
// Then from each parent down to the descendant.
descendant.parentToLocalCoordinates(localPoint);
}
public Actor hit(float x, float y) {
if (getTouchable() == Touchable.disabled) return null;
Array<Actor> children = this.children;
for (int i = children.size - 1; i >= 0; i--) {
Actor child = children.get(i);
if (!child.isVisible()) continue;
child.parentToLocalCoordinates(point.set(x, y));
Actor hit = child.hit(point.x, point.y);
if (hit != null) return hit;
}
return super.hit(x, y);
}
/**
* Transforms the specified point in the stage's coordinates to the actor's local coordinate
* system.
*/
public Vector2 stageToLocalCoordinates(Vector2 stageCoords) {
if (parent == null) return stageCoords;
parent.stageToLocalCoordinates(stageCoords);
parentToLocalCoordinates(stageCoords);
return stageCoords;
}