/// <summary>
/// runs three fail-over range checks for a given node
/// </summary>
/// <param name="node">node to check</param>
/// <param name="point">location from which range check is made</param>
/// <param name="range">the length of the range check</param>
/// <returns>true if in range, false if not</returns>
private bool nodeWithinRange(QuadNode <E> node, Vector2 point, float range)
{
if (node.contains(point))
{
return(true);
}
else if (Vector2.Distance(node.Center, point) <= range)
{
return(true);
}
else
{
//get the vector from the point to the node's center
Vector2 pToC = node.Center - point;
pToC.Normalize();
//find the closest position to the node center that is at max range from the point
pToC = point + pToC * range;
//if that point is within the node, then the node is within range
if (node.contains(pToC))
{
return(true);
}
}
//node not within range
return(false);
}
/// <summary>
/// sets the content at the leaf node descendant from the given node
/// </summary>
/// <param name="node">given node</param>
/// <param name="val">content to be set</param>
/// <param name="point">location of the content</param>
/// <returns>the leaf node set or null if set failed or content already exists</returns>
private QuadNode <E> setContentAtLocation(QuadNode <E> node, E val, Vector2 point)
{
if (node.Q1 == null || node.Q2 == null || node.Q3 == null || node.Q4 == null)
{
if (node.contains(point))
{
if (!node.Contents.Contains(val))
{
node.Contents.Add(val);
}
return(node);
}
else
{
return(null);
}
}
else
{
if (node.Q1.contains(point))
{
return(setContentAtLocation(node.Q1, val, point));
}
if (node.Q2.contains(point))
{
return(setContentAtLocation(node.Q2, val, point));
}
if (node.Q3.contains(point))
{
return(setContentAtLocation(node.Q3, val, point));
}
if (node.Q4.contains(point))
{
return(setContentAtLocation(node.Q4, val, point));
}
return(null);
}
}