Method insert

packages/melonjs/src/physics/broadphase/quadtree.ts:332–377

* Insert the given object into the node. If the node * exceeds the capacity, it will split and add all * objects to their corresponding subnodes. * @param item - object to be added

(item: QuadTreeItem)

	 * @param item - object to be added
	 */
	insert(item: QuadTreeItem) {
		// Subtree count: this insert adds one object SOMEWHERE in
		// this subtree (either to `this.objects` or, by recursion,
		// to a descendant's subtree). Bumping at every level entered
		// gives every ancestor a correct running total.
		this._subtreeCount++;

		//if we have subnodes ...
		if (this.nodes.length > 0) {
			const index = this.getIndex(item);

			if (index !== -1) {
				this.nodes[index].insert(item);
				return;
			}
		}

		this.objects.push(item);

		if (
			this.objects.length > this.max_objects &&
			this.level < this.max_levels
		) {
			//split if we don't already have subnodes
			if (this.nodes.length === 0) {
				this.split();
			}

			//add all objects to their corresponding subnodes
			let writeIdx = 0;
			for (let i = 0, len = this.objects.length; i < len; i++) {
				const subIndex = this.getIndex(this.objects[i]);
				if (subIndex !== -1) {
					// Redistribution: the item is being MOVED from
					// `this.objects` into a subnode. The total in this
					// subtree is unchanged, so we DON'T touch
					// `this._subtreeCount`. The subnode's `insert`
					// will increment its own count for the moved item.
					this.nodes[subIndex].insert(this.objects[i]);
				} else {
					this.objects[writeIdx++] = this.objects[i];
				}
			}
			this.objects.length = writeIdx;
		}
	}

	/**
	 * Recursively remove the given container and its descendants from