/// <summary>
/// Traverse the tree to fetch the node that contains the specified collideable object
/// </summary>
/// <param name="obj">collideable object</param>
/// <returns>The containing node</returns>
private Node FetchContaining(ICollides obj)
{
//guard
if (obj == null)
{
return(null);
}
//end condition (no more child nodes)
if (childNodes == null)
{
if (ICollidesList.Contains(obj))
{
return(this);
}
else
{
return(null);
}
}
else
{
//traverse
foreach (Node n in childNodes)
{
if (n.ContainsPos(obj.RealPos))
{
return(n.FetchContaining(obj));
}
}
return(null);
}
}
/// <summary>
/// Register collidable to the right node
/// </summary>
public void Register(ICollides obj)
{
//guards
if (obj == null)
{
return;
}
if (!SwinGame.RectOnScreen(grid))
{
return;
}
//end condition
if (childNodes == null)
{
ICollidesList.Add(obj);
return;
}
//find the node which contains the entiites position
foreach (Node n in childNodes)
{
//only explore traverse relevant nodes
if (n.ContainsPos(obj.RealPos))
{
n.Register(obj);
}
}
}
/// <summary>
/// clear the tree of all collideable entities
/// </summary>
public void Clear()
{
ICollidesList?.Clear();
if (childNodes == null)
{
return;
}
foreach (Node n in childNodes)
{
n.Clear();
}
}
