/// <summary>
/// Destroys the two way relationship between the object and the list.
/// </summary>
/// <param name="list">the list to remove the game object from</param>
/// <param name="gameObject">the game object to remove</param>
/// <returns>true if the removal was successful, false otherwise</returns>
protected internal static bool RemoveFromList(List<GameObject> list, GameObject gameObject)
{
//remove the game object from the list only if that list contains the object,
//and that objects lists belonging to field contains the list
if (gameObject._listsBelongingTo.Contains(list) && list.Contains(gameObject))
{
list.Remove(gameObject);
gameObject._listsBelongingTo.Remove(list);
//return true, as the removal was successful
return true;
}
//return false if there was no removal
return false;
}
/// <summary>
/// Establishes a two way relationship between the list the game object is being added to,
/// and the object being added to the list
/// </summary>
/// <param name="list">The list to add the game object to</param>
/// <param name="gameObject">the object to add</param>
protected internal static void AddToList(List<GameObject> list, GameObject gameObject)
{
///the two checks ensure an object is only ever added to a list once,
///and that the lists belonging to only every contains one instance of the list
if (!list.Contains(gameObject))
{
//add the entity to the list
list.Add(gameObject);
}
if (!gameObject._listsBelongingTo.Contains(list))
{
//add the list to the collection of lists the gameobject belongs to
gameObject._listsBelongingTo.Add(list);
}
}
private static int CompareByDrawLayer(GameObject a, GameObject b)
{
return a.DrawLayer.CompareTo(b.DrawLayer);
}
/// <summary>
/// Sets the Parent of this object to the given argument
/// </summary>
/// <param name="aParent">The parent of this object</param>
public void SetParent(GameObject aParent)
{
if (this._parent != null)
{
this._parent._children.Remove(this);
}
this._parent = aParent;
if (_parent != null)
{
_parent._children.Add(this);
}
this._topParent = GetHighestParent();
}
/// <summary>
/// Sets this Camera to follow a game object
/// </summary>
/// <param name="aTarget">The object to follow</param>
/// <param name="aOffsetVector">The offset of this camera's position relative to the target's position</param>
/// <param name="aFollowOffset">distance the camera should be from the target</param>
/// <param name="rotationOffset">the difference in rotation between the target and camera</param>
public void Follow(GameObject aTarget, Vector2 aOffsetVector, float aFollowOffset, float rotationOffset)
{
Target = aTarget;
OffsetVector = aOffsetVector;
FollowOffset = aFollowOffset;
SourceRotationOffset = rotationOffset;
}