////////////////////////////////////////////////////////////////////////////////
// js-graphics-mathlib
// Math library for JavaScript 2D/3D graphics rendering.
//
// MIT License (c) 2015-2019 Jingwood, All rights reserved.
////////////////////////////////////////////////////////////////////////////////

import { Vec3 } from "./vec3.js";

class SpaceTreeNode {
	constructor(origin, size) {
		if (typeof origin === "undefined") {
			this.origin = null;
			this.size = null;
			this.halfSize = null;
			this.minpos = null;
			this.maxpos = null;
		} else {
			this.origin = origin;
			this.size = size;
			this.halfSize = size.div(2);
			this.minpos = origin.sub(halfSize);
			this.maxpos = origin.add(halfSize);
		}

		this.splitted = false;
		this.splitNextDir = SpaceTree.ST_SplitX;
		this.left = null;
		this.right = null;
		this.list = [];
	}

	split(depth) {
		switch (this.splitNextDir) {
			case SpaceTree.ST_SplitX:
				{
					var halfHalfSize = this.halfSize.x / 2;
					var splittdBoxSize = new Vec3(this.halfSize.x, this.size.y, this.size.z);

					this.left = new SpaceTreeNode(new Vec3(origin.x - halfHalfSize,
						origin.y,
						origin.z), splittdBoxSize);

					this.right = new SpaceTreeNode(new Vec3(origin.x + halfHalfSize,
						origin.y,
						origin.z), splittdBoxSize);

					this.left.splitNextDir = SpaceTree.ST_SplitY;
					this.right.splitNextDir = SpaceTree.ST_SplitY;
				}
				break;

			case SpaceTree.ST_SplitY:
				{
					var halfHalfSize = this.halfSize.y / 2;
					var splittdBoxSize = new Vec3(this.size.x, this.halfSize.y, this.size.z);

					this.left = new SpaceTreeNode(new Vec3(origin.x,
						origin.y - halfHalfSize,
						origin.z), splittdBoxSize);

					this.right = new SpaceTreeNode(new Vec3(origin.x,
						origin.y + halfHalfSize,
						origin.z), splittdBoxSize);

					this.left.splitNextDir = SpaceTree.ST_SplitZ;
					this.right.splitNextDir = SpaceTree.ST_SplitZ;
				}
				break;

			case SpaceTree.ST_SplitZ:
				{
					var halfHalfSize = this.halfSize.z / 2;
					var splittdBoxSize = new Vec3(this.size.x, this.size.y, this.halfSize.z);

					this.left = new SpaceTreeNode(new Vec3(origin.x,
						origin.y,
						origin.z - halfHalfSize), splittdBoxSize);

					this.right = new SpaceTreeNode(new Vec3(origin.x,
						origin.y,
						origin.z + halfHalfSize), splittdBoxSize);

					this.left.splitNextDir = SpaceTree.ST_SplitX;
					this.right.splitNextDir = SpaceTree.ST_SplitX;
				}
				break;
		}

		this.splitted = true;

		if (depth < SpaceTree.MaxDepth) {
			this.left.split(depth + 1);
			this.right.split(depth + 1);
		}
	}

	intersectTriangle(t) {
		return MathFunctions.triangleIntersectBox(this.origin, this.halfSize, t);
	}

	intersectRay(r) {
		return MathFunctions.rayIntersectBox(r.origin, r.dir, this.minpos, this.maxpos, null);
	}
}

class SpaceTree {
	constructor() {
		this.root = new SpaceTreeNode();
	}

	init(spaceSize) {
		if (typeof spaceSize === "undefined") {
			spaceSize = 30;
		}

		var halfSize = spaceSize / 2.0;

		this.root.origin = new Vec3(0, 0, 0);
		this.root.size = new Vec3(spaceSize, spaceSize, spaceSize);
		this.root.halfSize = new Vec3(halfSize, halfSize, halfSize);

		this.root.split(maxDepth);
	}
}

SpaceTree.SplitDirs = {
	ST_SplitX: 0,
	ST_SplitY: 1,
	ST_SplitZ: 2,
};

SpaceTree.MaxDepth = 2;