public IEnumerable <T> Query(Vector2 point, float radius)
{
var root = rootNode;
if (QuadTreeUtils.Overlaps(root.Bounds, point, radius))
{
return(root.Query(point, radius));
}
return(Enumerable.Empty <T>());
}
private QuadTreeNode <T>[] CreateChildren()
{
var rects = QuadTreeUtils.DevideQuads(Bounds);
var children = new QuadTreeNode <T> [rects.Length];
for (int i = 0; i < children.Length; i++)
{
children[i] = new QuadTreeNode <T>(tree, this, rects[i], i);
}
return(children);
}
private QuadTreeNode <T> Grow(QuadTreeNode <T> rootNode, Rect bounds)
{
var newBounds = QuadTreeUtils.GrowQuad(rootNode.Bounds, bounds.center, out int sourceIndex, out int index);
var quads = QuadTreeUtils.DevideQuads(newBounds);
var children = new QuadTreeNode <T> [4];
for (int i = 0; i < 4; i++)
{
if (i == index)
{
children[i] = rootNode;
}
else
{
children[i] = new QuadTreeNode <T>(this, quads[i]);
}
}
return(new QuadTreeNode <T>(this, children, newBounds));
}
internal QuadTreeNode <T> Add(T item)
{
var index = QuadTreeUtils.GetQuadIndex(Bounds, item.Bounds.center);
if (bounds.size.x > tree.MinSize.x && bounds.size.y > tree.MinSize.y)
{
if (children == null)
{
lock (childrenLock)
if (children == null)
{
children = CreateChildren();
}
}
if (children[index].Encapsulates(item.Bounds))
{
return(children[index].Add(item));
}
}
this.items.Add(item);
InvalidateBounds();
return(this);
}
internal bool Encapsulates(Rect bounds) => QuadTreeUtils.Encapsulates(maxBounds, bounds) && this.bounds.Contains(bounds.center);