420 lines
15 KiB
C#
420 lines
15 KiB
C#
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using Quadtree.Items;
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using System.Collections.Generic;
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using System.Linq;
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using UnityEngine;
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#if UNITY_EDITOR
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using UnityEditor;
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#endif
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namespace Quadtree
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{
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/// <summary>
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/// Base quadtree node implementation.
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/// </summary>
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public abstract class NodeBase<TItem, TNode> : INode<TItem, TNode>
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where TItem : IItem<TItem, TNode>
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where TNode : NodeBase<TItem, TNode>, new()
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{
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public Bounds Bounds { get; set; }
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public TNode ParentNode { get; set; }
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public IList<TNode> SubNodes { get; set; }
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public IQuadtreeRoot<TItem, TNode> TreeRoot { get; set; }
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/// <summary>
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/// List of inserted items.
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/// </summary>
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private readonly HashSet<TItem> _items;
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public NodeBase()
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{
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SubNodes = new List<TNode>(4);
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_items = new HashSet<TItem>();
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}
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/// <summary>
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/// Verifies whether provided boundaries (<paramref name="bounds"/>) are fully contained within the boundaries of the node.
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/// </summary>
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///
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/// <param name="bounds">Boundaries of an object</param>
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/// <returns><c>True</c> if object is fully contained within the node, <c>False</c> otherwise</returns>
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public bool Contains(Bounds bounds) =>
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bounds.min.x >= Bounds.min.x
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&& bounds.min.z >= Bounds.min.z
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&& bounds.max.x < Bounds.max.x
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&& bounds.max.z < Bounds.max.z;
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public IntraLocation Location(Bounds bounds)
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{
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if (bounds.min.z >= Bounds.center.z)
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{
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// items are located in top sub-nodes
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if (bounds.max.x < Bounds.center.x)
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{
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// items are located in top left sub-node
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return IntraLocation.UPPER_LEFT;
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}
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else if (bounds.min.x >= Bounds.center.x)
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{
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// items are located in top right sub-node
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return IntraLocation.UPPER_RIGHT;
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}
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else
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{
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// item does not fit to either one, but is top
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// (max.x is right, min.x is left)
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return IntraLocation.SPANNING_UPPER;
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}
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}
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else if (bounds.max.z < Bounds.center.z)
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{
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// items are located in bottom sub-nodes
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if (bounds.max.x < Bounds.center.x)
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{
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// items are located in bottom left sub-node
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return IntraLocation.LOWER_LEFT;
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}
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else if (bounds.min.x >= Bounds.center.x)
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{
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// items are located in bottom right sub-node
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return IntraLocation.LOWER_RIGHT;
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}
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else
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{
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// item does not fit to either one, but is bottom
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// (max.x is right, min.x is left)
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return IntraLocation.SPANNING_LOWER;
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}
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}
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else
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{
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// item does not fit to any sub-node
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// (max.z is top, min.z is bottom)
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if (bounds.min.x >= Bounds.center.x)
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{
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// bounds span over top right and bottom right nodes
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return IntraLocation.SPANNING_RIGHT;
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}
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else if (bounds.max.x < Bounds.center.x)
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{
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// bounds span over top left and bottom left nodes
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return IntraLocation.SPANNING_LEFT;
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}
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else
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{
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// bounds span over all sub-nodes
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return IntraLocation.SPANNING;
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}
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}
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}
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public void Insert(TItem item)
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{
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// create new sub-nodes
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if (SubNodes.Count == 0)
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CreateSubNodes();
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// sub-nodes can not be created anymore
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if (SubNodes.Count == 0)
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{
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// insert item into this node
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_items.Add(item);
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// and designate this node its parent
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item.ParentNode = (TNode)this;
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return;
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}
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var itemBounds = item.GetBounds();
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var itemBoundsLocation = Location(itemBounds);
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switch (itemBoundsLocation)
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{
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// boundaries are contained within one of the subnodes
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case IntraLocation.UPPER_LEFT:
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case IntraLocation.UPPER_RIGHT:
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case IntraLocation.LOWER_RIGHT:
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case IntraLocation.LOWER_LEFT:
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SubNodes[(int)itemBoundsLocation].Insert(item);
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break;
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// boundaries are spanning over 2 or more subnodes
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default:
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_items.Add(item);
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item.ParentNode = (TNode)this;
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break;
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}
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}
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public void Remove(TItem item)
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{
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var itemBounds = item.GetBounds();
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var itemBoundsLocation = Location(itemBounds);
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switch (itemBoundsLocation)
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{
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// boundaries are contained within one of the subnodes
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case IntraLocation.UPPER_LEFT:
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case IntraLocation.UPPER_RIGHT:
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case IntraLocation.LOWER_RIGHT:
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case IntraLocation.LOWER_LEFT:
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SubNodes[(int)itemBoundsLocation].Remove(item);
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break;
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// boundaries are spanning over 2 or more subnodes
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default:
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RemoveOwnItem(item);
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break;
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}
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}
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/// <summary>
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/// Removes provided item (<paramref name="item"/>) from the node.
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/// </summary>
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///
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/// <param name="item">Item to be removed from the node</param>
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///
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/// <seealso cref="INode{TItem, TNode}.Clear"/>
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protected internal void RemoveOwnItem(TItem item)
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{
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// remove the item from the node
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_items.Remove(item);
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// update its parent node
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item.ParentNode = null;
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if (IsEmpty())
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{
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// remove subnodes if subtree of this node is empty
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SubNodes.Clear();
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}
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}
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public bool IsEmpty()
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{
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if (_items.Count > 0)
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return false;
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foreach (var subNode in SubNodes)
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if (!subNode.IsEmpty())
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return false;
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return true;
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}
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public void Update(TItem item, bool forceInsertionEvaluation = true, bool hasOriginallyContainedItem = true)
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{
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if (Contains(item.GetBounds()))
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{
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// item is contained by this node
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if (hasOriginallyContainedItem)
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{
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// ...and this node has originally contained the item
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if (forceInsertionEvaluation)
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{
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// ...and insertion evaluation is forced
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// this checks whether the item hasn't moved into any of the subnodes
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RemoveOwnItem(item);
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Insert(item);
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}
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// item is still contained by its original node, no action necessary
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return;
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}
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// ...but this node is not its original container
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// insert item either to this node or any of its children
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Insert(item);
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// update has been successful
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return;
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}
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// the item is not contained by this node
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if (ParentNode == null)
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{
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// ...and this node does not have any parent - the tree must be expanded
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TreeRoot.Expand();
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if (ParentNode == null)
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{
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// the expansion has failed for some reason
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Debug.LogError("Tree root expansion failed for item " + item.ToString());
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return;
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}
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}
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// the item is not contained by this node
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if (hasOriginallyContainedItem)
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{
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// ...and this node has originally contained the item - it must be removed
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RemoveOwnItem(item);
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}
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// parent is (now) available
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ParentNode.Update(item, forceInsertionEvaluation, false);
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// the item is now contained by another node, update has been successful
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}
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/// <summary>
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/// Creates sub-nodes for the node.
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/// </summary>
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protected internal void CreateSubNodes()
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{
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var subBoundsSize = Bounds.size * .5f;
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if (subBoundsSize.x < TreeRoot.MinimumPossibleNodeSize
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|| subBoundsSize.z < TreeRoot.MinimumPossibleNodeSize)
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{
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// new sub-node bounds are too small
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return;
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}
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var centerOffset = subBoundsSize * .5f;
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// top left node [-x +z]
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centerOffset.x *= -1f;
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SubNodes.Insert((int)IntraLocation.UPPER_LEFT, new TNode()
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{
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TreeRoot = TreeRoot,
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ParentNode = (TNode)this,
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Bounds = new Bounds(Bounds.center + centerOffset, subBoundsSize),
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});
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// top right node [+x +z]
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centerOffset.x *= -1f;
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SubNodes.Insert((int)IntraLocation.UPPER_RIGHT, new TNode()
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{
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TreeRoot = TreeRoot,
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ParentNode = (TNode)this,
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Bounds = new Bounds(Bounds.center + centerOffset, subBoundsSize),
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});
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// bottom right node [+x -z]
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centerOffset.z *= -1f;
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SubNodes.Insert((int)IntraLocation.LOWER_RIGHT, new TNode()
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{
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TreeRoot = TreeRoot,
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ParentNode = (TNode)this,
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Bounds = new Bounds(Bounds.center + centerOffset, subBoundsSize),
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});
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// bottom left node [-x -z]
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centerOffset.x *= -1f;
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SubNodes.Insert((int)IntraLocation.LOWER_LEFT, new TNode()
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{
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TreeRoot = TreeRoot,
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ParentNode = (TNode)this,
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Bounds = new Bounds(Bounds.center + centerOffset, subBoundsSize),
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});
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}
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public void FindAndAddItems(Bounds bounds, ref IList<TItem> items)
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{
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if (SubNodes.Count == 0)
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{
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// no sub-nodes exist
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AddOwnItems(ref items);
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return;
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}
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// always add any items in this node intersecting with the boundaries
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AddOwnItems(ref items, bounds);
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var boundsLocation = Location(bounds);
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switch (boundsLocation)
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{
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// boundaries are contained within one of the subnodes
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case IntraLocation.UPPER_LEFT:
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case IntraLocation.UPPER_RIGHT:
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case IntraLocation.LOWER_RIGHT:
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case IntraLocation.LOWER_LEFT:
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SubNodes[(int)boundsLocation].FindAndAddItems(bounds, ref items);
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break;
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// boundaries are spanning over left subnodes
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case IntraLocation.SPANNING_LEFT:
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SubNodes[(int)IntraLocation.UPPER_LEFT].AddItems(ref items, bounds);
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SubNodes[(int)IntraLocation.LOWER_LEFT].AddItems(ref items, bounds);
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break;
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// boundaries are spanning over right subnodes
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case IntraLocation.SPANNING_RIGHT:
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SubNodes[(int)IntraLocation.UPPER_RIGHT].AddItems(ref items, bounds);
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SubNodes[(int)IntraLocation.LOWER_RIGHT].AddItems(ref items, bounds);
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break;
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// boundaries are spanning over upper subnodes
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case IntraLocation.SPANNING_UPPER:
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SubNodes[(int)IntraLocation.UPPER_LEFT].AddItems(ref items, bounds);
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SubNodes[(int)IntraLocation.UPPER_RIGHT].AddItems(ref items, bounds);
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break;
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// boundaries are spanning over lower subnodes
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case IntraLocation.SPANNING_LOWER:
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SubNodes[(int)IntraLocation.LOWER_LEFT].AddItems(ref items, bounds);
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SubNodes[(int)IntraLocation.LOWER_RIGHT].AddItems(ref items, bounds);
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break;
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// boundaries are spanning over all subnodes
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case IntraLocation.SPANNING:
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default:
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AddSubNodeItems(ref items, bounds);
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break;
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}
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}
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public void AddItems(ref IList<TItem> items, Bounds? bounds = null)
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{
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AddOwnItems(ref items, bounds);
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AddSubNodeItems(ref items, bounds);
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}
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/// <summary>
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/// Adds all items belonging to this node (ignoring sub-nodes) to the provided list of items (<paramref name="items"/>).
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/// If boundaries (<paramref name="bounds"/>) are provided then only items intersecting with them will be added.
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/// </summary>
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///
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/// <param name="items">Output list for found items</param>
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/// <param name="bounds">Boundaries to look for items within</param>
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protected internal void AddOwnItems(ref IList<TItem> items, Bounds? bounds = null)
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{
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var itemSource = bounds != null
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|||
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|
? _items.Where(item => item.GetBounds().Intersects((Bounds)bounds))
|
|||
|
|
: _items;
|
|||
|
|
|
|||
|
|
foreach (var item in itemSource)
|
|||
|
|
{
|
|||
|
|
items.Add(item);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Adds all items belonging to sub-nodes (ignoring own items) to the provided list of items (<paramref name="items"/>).
|
|||
|
|
/// If boundaries (<paramref name="bounds"/>) are provided then only items intersecting with them will be added.
|
|||
|
|
/// </summary>
|
|||
|
|
///
|
|||
|
|
/// <param name="items">Output list for found items</param>
|
|||
|
|
/// <param name="bounds">Boundaries to look for items within</param>
|
|||
|
|
protected internal void AddSubNodeItems(ref IList<TItem> items, Bounds? bounds = null)
|
|||
|
|
{
|
|||
|
|
foreach (var subNode in SubNodes)
|
|||
|
|
subNode.AddItems(ref items, bounds);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
public void Clear()
|
|||
|
|
{
|
|||
|
|
_items.Clear();
|
|||
|
|
SubNodes.Clear();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
public void DrawBounds(bool displayNumberOfItems = false)
|
|||
|
|
{
|
|||
|
|
#if UNITY_EDITOR
|
|||
|
|
if (displayNumberOfItems)
|
|||
|
|
Handles.Label(Bounds.center, _items.Count.ToString());
|
|||
|
|
|
|||
|
|
Gizmos.DrawWireCube(Bounds.center, Bounds.size);
|
|||
|
|
#endif
|
|||
|
|
foreach (var subNode in SubNodes)
|
|||
|
|
subNode.DrawBounds(displayNumberOfItems);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|