/*************************************************************************/
/*  bsp_tree.h                                                           */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
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/* distribute, sublicense, and/or sell copies of the Software, and to    */
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/*************************************************************************/
#ifndef BSP_TREE_H
#define BSP_TREE_H

#include "plane.h"
#include "aabb.h"
#include "face3.h"
#include "vector.h"
#include "dvector.h"

#include "variant.h"
/**
	@author Juan Linietsky <reduzio@gmail.com>
*/
class BSP_Tree {
public:

	enum {
	
		UNDER_LEAF=0xFFFF,
		OVER_LEAF=0xFFFE,
		MAX_NODES=0xFFFE,
		MAX_PLANES=(1<<16)
	};

	struct Node {
		
		uint16_t plane;
		uint16_t under;
		uint16_t over;
	};

	
private:	
	// thanks to the properties of Vector, 
	// this class can be assigned and passed around between threads
	// with no cost.
	
	Vector<Node> nodes;
	Vector<Plane> planes;
	AABB aabb;
	float error_radius;	

	int _get_points_inside(int p_node,const Vector3* p_points,int *p_indices, const Vector3& p_center,const Vector3& p_half_extents,int p_indices_count) const;

	template<class T>
	bool _test_convex(const Node* p_nodes, const Plane* p_planes,int p_current, const T& p_convex) const;

public:

	bool is_empty() const { return nodes.size()==0; }
	Vector<Node> get_nodes() const;
	Vector<Plane> get_planes() const;
	AABB get_aabb() const;
		
	bool point_is_inside(const Vector3& p_point) const;		
	int get_points_inside(const Vector3* p_points, int p_point_count) const;
	template<class T>
	bool convex_is_inside(const T& p_convex) const;

	operator Variant() const;

	void from_aabb(const AABB& p_aabb);

	BSP_Tree();
	BSP_Tree(const Variant& p_variant);
	BSP_Tree(const DVector<Face3>& p_faces,float p_error_radius=0);	
	BSP_Tree(const Vector<Node> &p_nodes, const Vector<Plane> &p_planes, const AABB& p_aabb,float p_error_radius=0);	
	~BSP_Tree();

};

template<class T>
bool BSP_Tree::_test_convex(const Node* p_nodes, const Plane* p_planes,int p_current, const T& p_convex) const {

	if (p_current==UNDER_LEAF)
		return true;
	else if (p_current==OVER_LEAF)
		return false;

	bool collided=false;
	const Node&n=p_nodes[p_current];

	const Plane& p=p_planes[n.plane];

	float min,max;
	p_convex.project_range(p.normal,min,max);

	bool go_under = min < p.d;
	bool go_over = max >= p.d;

	if (go_under && _test_convex(p_nodes,p_planes,n.under,p_convex))
		collided=true;
	if (go_over && _test_convex(p_nodes,p_planes,n.over,p_convex))
		collided=true;

	return collided;

}

template<class T>
bool BSP_Tree::convex_is_inside(const T& p_convex) const {

	int node_count = nodes.size();
	if (node_count==0)
		return false;
	const Node* nodes=&this->nodes[0];
	const Plane* planes = &this->planes[0];

	return _test_convex(nodes,planes,node_count-1,p_convex);
}


#endif
