/// <summary>
/// Adds an item with the given bounds into the octree.
/// </summary>
/// <param name="bounds">The bounds of the item.</param>
/// <param name="value">The item to add.</param>
/// <returns></returns>
public BoundsOctreeItem <T> Add(Bounds3 bounds, T value)
{
var item = new BoundsOctreeItem <T>(bounds, value);
if (children == null)
{
CreateInitialOctree(item);
return(item);
}
if (Level < item.Level)
{
Expand(item);
}
var octant = GetOctant(bounds.Center);
if (children[octant] == null)
{
children[octant] = new BoundingOctreeNode <T>(Level, GetOriginIndex3(octant));
}
children[octant].Add(item);
return(item);
}
public void Add(BoundsOctreeItem <T> item)
{
if (!Bounds.Intersects(item.Bounds))
{
throw new ArgumentOutOfRangeException();
}
if (item.Level > Level)
{
throw new ArgumentOutOfRangeException();
}
if (item.Level == Level)
{
Items.Add(item);
return;
}
var octant = GetOctant(item.Bounds.Center);
if (children == null)
{
if (Items.Count < EdgeThreshold)
{
// Add and continue
Items.Add(item);
return;
}
// Fork children
children = new BoundingOctreeNode <T> [8];
for (int i = Items.Count - 1; i >= 0; i--)
{
// Find the target level, if lower, add to child.
if (Items[i].Level < Level)
{
var removed = Items[i];
Items.RemoveAt(i);
Add(removed);
}
}
}
if (children[octant] == null)
{
children[octant] = new BoundingOctreeNode <T>(Level - 1, GetChildIndex(octant));
}
children[octant].Add(item);
}
private void CreateInitialOctree(BoundsOctreeItem <T> item)
{
Level = item.Level;
var side = Functions.Pow(2, Level);
Bounds = new Bounds3(-side, -side, -side, side, side, side);
children = new BoundingOctreeNode <T> [8];
var octant = GetOctant(item.Bounds.Center);
children[octant] = new BoundingOctreeNode <T>(Level, GetOriginIndex3(octant));
children[octant].Add(item);
}
private void Expand(BoundsOctreeItem <T> item)
{
for (int l = Level; l < item.Level; l++)
{
Level += 1;
for (int i = 0; i < 8; i++)
{
if (children[i] != null)
{
var parent = new BoundingOctreeNode <T>(Level, children[i].Index);
parent.children = new BoundingOctreeNode <T> [8];
parent.children[GetOpposingOctant(i)] = children[i];
children[i] = parent;
}
}
}
}