/*************************************************************************/
/*  octree.h                                                             */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2017 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   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#ifndef OCTREE_H
#define OCTREE_H

#include "vector3.h"
#include "aabb.h"
#include "list.h"
#include "variant.h"
#include "map.h"
#include "print_string.h"

/**
	@author Juan Linietsky <reduzio@gmail.com>
*/

typedef uint32_t OctreeElementID;

#define OCTREE_ELEMENT_INVALID_ID 0
#define OCTREE_SIZE_LIMIT 1e15

template<class T,bool use_pairs=false,class AL=DefaultAllocator>
class Octree {
public:

	typedef void* (*PairCallback)(void*,OctreeElementID, T*,int,OctreeElementID, T*,int);
	typedef void (*UnpairCallback)(void*,OctreeElementID, T*,int,OctreeElementID, T*,int,void*);

private:
	enum {

		NEG=0,
		POS=1,
	};

	enum {
		OCTANT_NX_NY_NZ,
		OCTANT_PX_NY_NZ,
		OCTANT_NX_PY_NZ,
		OCTANT_PX_PY_NZ,
		OCTANT_NX_NY_PZ,
		OCTANT_PX_NY_PZ,
		OCTANT_NX_PY_PZ,
		OCTANT_PX_PY_PZ
	};


	struct PairKey {

		union {
			struct {
				OctreeElementID A;
				OctreeElementID B;
			};
			uint64_t key;
		};

		_FORCE_INLINE_ bool operator<(const PairKey& p_pair) const {

			return key<p_pair.key;
		}

		_FORCE_INLINE_ PairKey( OctreeElementID p_A, OctreeElementID p_B) {

			if (p_A<p_B) {

				A=p_A;
				B=p_B;
			} else {

				B=p_A;
				A=p_B;
			}
		}

		_FORCE_INLINE_ PairKey() {}
	};

	struct Element;

	struct Octant {

		// cached for FAST plane check
		Rect3 aabb;

		uint64_t last_pass;
		Octant *parent;
		Octant *children[8];

		int children_count; // cache for amount of childrens (fast check for removal)
		int parent_index; // cache for parent index (fast check for removal)

		List<Element*,AL> pairable_elements;
		List<Element*,AL> elements;

		Octant() {
			children_count=0;
			parent_index=-1;
			last_pass=0;
			parent=NULL;
			for (int i=0;i<8;i++)
				children[i]=NULL;
		}

		~Octant() {

			/*
			for (int i=0;i<8;i++)
				memdelete_notnull(children[i]);
			*/
		}
	};


	struct PairData;

	struct Element {

		Octree *octree;

		T *userdata;
		int subindex;
		bool pairable;
		uint32_t pairable_mask;
		uint32_t pairable_type;

		uint64_t last_pass;
		OctreeElementID _id;
		Octant *common_parent;

		Rect3 aabb;
		Rect3 container_aabb;

		List<PairData*,AL> pair_list;

		struct OctantOwner {

			Octant *octant;
			typename List<Element*,AL>::Element *E;
		}; // an element can be in max 8 octants

		List<OctantOwner,AL> octant_owners;


		Element() { last_pass=0; _id=0; pairable=false; subindex=0; userdata=0; octree=0; pairable_mask=0; pairable_type=0; common_parent=NULL; }
	};


	struct PairData {

		int refcount;
		bool intersect;
		Element *A,*B;
		void *ud;
		typename List<PairData*,AL>::Element *eA,*eB;
	};

	typedef Map<OctreeElementID, Element, Comparator<OctreeElementID>, AL> ElementMap;
	typedef Map<PairKey, PairData, Comparator<PairKey>, AL> PairMap;
	ElementMap element_map;
	PairMap pair_map;

	PairCallback pair_callback;
	UnpairCallback unpair_callback;
	void *pair_callback_userdata;
	void *unpair_callback_userdata;

	OctreeElementID last_element_id;
	uint64_t pass;

	real_t unit_size;
	Octant *root;
	int octant_count;
	int pair_count;



	_FORCE_INLINE_ void _pair_check(PairData *p_pair) {

		bool intersect=p_pair->A->aabb.intersects_inclusive( p_pair->B->aabb );

		if (intersect!=p_pair->intersect) {

			if (intersect) {

				if (pair_callback) {
					p_pair->ud=pair_callback(pair_callback_userdata,p_pair->A->_id, p_pair->A->userdata,p_pair->A->subindex,p_pair->B->_id, p_pair->B->userdata,p_pair->B->subindex);

				}
				pair_count++;
			} else {


				if (unpair_callback) {
					unpair_callback(pair_callback_userdata,p_pair->A->_id, p_pair->A->userdata,p_pair->A->subindex,p_pair->B->_id, p_pair->B->userdata,p_pair->B->subindex,p_pair->ud);
				}
				pair_count--;

			}

			p_pair->intersect=intersect;

		}
	}

	_FORCE_INLINE_ void _pair_reference(Element* p_A,Element* p_B) {

		if (p_A==p_B || (p_A->userdata==p_B->userdata && p_A->userdata))
			return;

		if ( 	!(p_A->pairable_type&p_B->pairable_mask) &&
			!(p_B->pairable_type&p_A->pairable_mask) )
			return; // none can pair with none

		PairKey key(p_A->_id, p_B->_id);
		typename PairMap::Element *E=pair_map.find(key);

		if (!E) {

			PairData pdata;
			pdata.refcount=1;
			pdata.A=p_A;
			pdata.B=p_B;
			pdata.intersect=false;
			E=pair_map.insert(key,pdata);
			E->get().eA=p_A->pair_list.push_back(&E->get());
			E->get().eB=p_B->pair_list.push_back(&E->get());

			/*
			if (pair_callback)
				pair_callback(pair_callback_userdata,p_A->userdata,p_B->userdata);
			*/
		} else {

			E->get().refcount++;
		}

	}

	_FORCE_INLINE_ void _pair_unreference(Element* p_A,Element* p_B) {

		if (p_A==p_B)
			return;

		PairKey key(p_A->_id, p_B->_id);
		typename PairMap::Element *E=pair_map.find(key);
		if (!E) {
			return; // no pair
		}

		E->get().refcount--;


		if (E->get().refcount==0) {
			// bye pair

			if (E->get().intersect) {
				if (unpair_callback) {
					unpair_callback(pair_callback_userdata,p_A->_id, p_A->userdata,p_A->subindex,p_B->_id, p_B->userdata,p_B->subindex,E->get().ud);
				}

				pair_count--;
			}

			if (p_A==E->get().B) {
				//may be reaching inverted
				SWAP(p_A,p_B);
			}

			p_A->pair_list.erase( E->get().eA );
			p_B->pair_list.erase( E->get().eB );
			pair_map.erase(E);
		}

	}

	_FORCE_INLINE_ void _element_check_pairs(Element *p_element) {

		typename List<PairData*,AL>::Element *E=p_element->pair_list.front();
		while(E) {

			_pair_check( E->get() );
			E=E->next();
		}

	}

	_FORCE_INLINE_ void _optimize() {


		while(root && root->children_count<2 && !root->elements.size() && !(use_pairs && root->pairable_elements.size())) {


			Octant *new_root=NULL;
			if (root->children_count==1) {

				for(int i=0;i<8;i++) {

					if (root->children[i]) {
						new_root=root->children[i];
						root->children[i]=NULL;
						break;
					}
				}
				ERR_FAIL_COND(!new_root);
				new_root->parent=NULL;
				new_root->parent_index=-1;
			}

			memdelete_allocator<Octant,AL>( root );
			octant_count--;
			root=new_root;

		}
	}


	void _insert_element(Element *p_element,Octant *p_octant);
	void _ensure_valid_root(const Rect3& p_aabb);
	bool _remove_element_from_octant(Element *p_element,Octant *p_octant,Octant *p_limit=NULL);
	void _remove_element(Element *p_element);
	void _pair_element(Element *p_element,Octant *p_octant);
	void _unpair_element(Element *p_element,Octant *p_octant);


	struct _CullConvexData {

		const Plane* planes;
		int plane_count;
		T** result_array;
		int *result_idx;
		int result_max;
		uint32_t mask;
	};

	void _cull_convex(Octant *p_octant,_CullConvexData *p_cull);
	void _cull_AABB(Octant *p_octant,const Rect3& p_aabb, T** p_result_array,int *p_result_idx,int p_result_max,int *p_subindex_array,uint32_t p_mask);
	void _cull_segment(Octant *p_octant,const Vector3& p_from, const Vector3& p_to,T** p_result_array,int *p_result_idx,int p_result_max,int *p_subindex_array,uint32_t p_mask);
	void _cull_point(Octant *p_octant,const Vector3& p_point,T** p_result_array,int *p_result_idx,int p_result_max,int *p_subindex_array,uint32_t p_mask);

	void _remove_tree(Octant *p_octant) {

		if (!p_octant)
			return;

		for(int i=0;i<8;i++) {

			if (p_octant->children[i])
				_remove_tree(p_octant->children[i]);
		}

		memdelete_allocator<Octant,AL>(p_octant);
	}
public:

	OctreeElementID create(T* p_userdata, const Rect3& p_aabb=Rect3(), int p_subindex=0, bool p_pairable=false,uint32_t p_pairable_type=0,uint32_t pairable_mask=1);
	void move(OctreeElementID p_id, const Rect3& p_aabb);
	void set_pairable(OctreeElementID p_id,bool p_pairable=false,uint32_t p_pairable_type=0,uint32_t pairable_mask=1);
	void erase(OctreeElementID p_id);

	bool is_pairable(OctreeElementID p_id) const;
	T *get(OctreeElementID p_id) const;
	int get_subindex(OctreeElementID p_id) const;

	int cull_convex(const Vector<Plane>& p_convex,T** p_result_array,int p_result_max,uint32_t p_mask=0xFFFFFFFF);
	int cull_AABB(const Rect3& p_aabb,T** p_result_array,int p_result_max,int *p_subindex_array=NULL,uint32_t p_mask=0xFFFFFFFF);
	int cull_segment(const Vector3& p_from, const Vector3& p_to,T** p_result_array,int p_result_max,int *p_subindex_array=NULL,uint32_t p_mask=0xFFFFFFFF);

	int cull_point(const Vector3& p_point,T** p_result_array,int p_result_max,int *p_subindex_array=NULL,uint32_t p_mask=0xFFFFFFFF);

	void set_pair_callback( PairCallback p_callback, void *p_userdata );
	void set_unpair_callback( UnpairCallback p_callback, void *p_userdata );

	int get_octant_count() const { return octant_count; }
	int get_pair_count() const { return pair_count; }
	Octree(real_t p_unit_size=1.0);
	~Octree() { _remove_tree(root); }
};


/* PRIVATE FUNCTIONS */

template<class T,bool use_pairs,class AL>
T *Octree<T,use_pairs,AL>::get(OctreeElementID p_id) const {
	const typename ElementMap::Element *E = element_map.find(p_id);
	ERR_FAIL_COND_V(!E,NULL);
	return E->get().userdata;
}


template<class T,bool use_pairs,class AL>
bool Octree<T,use_pairs,AL>::is_pairable(OctreeElementID p_id) const {

	const typename ElementMap::Element *E = element_map.find(p_id);
	ERR_FAIL_COND_V(!E,false);
	return E->get().pairable;
}

template<class T,bool use_pairs,class AL>
int Octree<T,use_pairs,AL>::get_subindex(OctreeElementID p_id) const {

	const typename ElementMap::Element *E = element_map.find(p_id);
	ERR_FAIL_COND_V(!E,-1);
	return E->get().subindex;
}

#define OCTREE_DIVISOR 4

template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_insert_element(Element *p_element,Octant *p_octant) {

	float element_size = p_element->aabb.get_longest_axis_size() * 1.01; // avoid precision issues

	if (p_octant->aabb.size.x/OCTREE_DIVISOR < element_size) {
	//if (p_octant->aabb.size.x*0.5 < element_size) {

		/* at smallest possible size for the element  */
		typename Element::OctantOwner owner;
		owner.octant=p_octant;

		if (use_pairs && p_element->pairable) {

			p_octant->pairable_elements.push_back(p_element);
			owner.E = p_octant->pairable_elements.back();
		} else {

			p_octant->elements.push_back(p_element);
			owner.E = p_octant->elements.back();
		}

		p_element->octant_owners.push_back( owner );

		if (p_element->common_parent==NULL) {
			p_element->common_parent=p_octant;
			p_element->container_aabb=p_octant->aabb;
		} else {
			p_element->container_aabb.merge_with(p_octant->aabb);
		}


		if (use_pairs && p_octant->children_count>0) {

			pass++; //elements below this only get ONE reference added

			for (int i=0;i<8;i++) {

				if (p_octant->children[i]) {
					_pair_element(p_element,p_octant->children[i]);
				}
			}
		}
	} else {
		/* not big enough, send it to subitems */
		int splits=0;
		bool candidate=p_element->common_parent==NULL;

		for (int i=0;i<8;i++) {

			if (p_octant->children[i]) {
				/* element exists, go straight to it */
				if (p_octant->children[i]->aabb.intersects_inclusive( p_element->aabb ) ) {
					_insert_element( p_element, p_octant->children[i] );
					splits++;
				}
			} else {
				/* check againt AABB where child should be */

				Rect3 aabb=p_octant->aabb;
				aabb.size*=0.5;

				if (i&1)
					aabb.pos.x+=aabb.size.x;
				if (i&2)
					aabb.pos.y+=aabb.size.y;
				if (i&4)
					aabb.pos.z+=aabb.size.z;

				if (aabb.intersects_inclusive( p_element->aabb) ) {
					/* if actually intersects, create the child */

					Octant *child = memnew_allocator( Octant, AL );
					p_octant->children[i]=child;
					child->parent=p_octant;
					child->parent_index=i;

					child->aabb=aabb;

					p_octant->children_count++;

					_insert_element( p_element, child );
					octant_count++;
					splits++;

				}
			}

		}

		if (candidate && splits>1) {

			p_element->common_parent=p_octant;
		}

	}

	if (use_pairs) {

		typename List<Element*,AL>::Element *E=p_octant->pairable_elements.front();

		while(E) {
			_pair_reference( p_element,E->get() );
			E=E->next();
		}

		if (p_element->pairable) {
			// and always test non-pairable if element is pairable
			E=p_octant->elements.front();
			while(E) {
				_pair_reference( p_element,E->get() );
				E=E->next();
			}
		}
	}


}


template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_ensure_valid_root(const Rect3& p_aabb) {

	if (!root) {
		// octre is empty

		Rect3 base( Vector3(), Vector3(1.0,1.0,1.0) * unit_size);

		while ( !base.encloses(p_aabb) ) {

			if ( ABS(base.pos.x+base.size.x) <= ABS(base.pos.x) ) {
				/* grow towards positive */
				base.size*=2.0;
			} else {
				base.pos-=base.size;
				base.size*=2.0;
			}
		}

		root = memnew_allocator( Octant, AL );

		root->parent=NULL;
		root->parent_index=-1;
		root->aabb=base;

		octant_count++;


	} else {

		Rect3 base=root->aabb;

		while( !base.encloses( p_aabb ) ) {

			if (base.size.x > OCTREE_SIZE_LIMIT) {
				ERR_EXPLAIN("Octree upper size limit reeached, does the AABB supplied contain NAN?");
				ERR_FAIL();
			}

			Octant * gp = memnew_allocator( Octant, AL );
			octant_count++;
			root->parent=gp;

			if ( ABS(base.pos.x+base.size.x) <= ABS(base.pos.x) ) {
				/* grow towards positive */
				base.size*=2.0;
				gp->aabb=base;
				gp->children[0]=root;
				root->parent_index=0;
			} else {
				base.pos-=base.size;
				base.size*=2.0;
				gp->aabb=base;
				gp->children[(1<<0)|(1<<1)|(1<<2)]=root; // add at all-positive
				root->parent_index=(1<<0)|(1<<1)|(1<<2);
			}

			gp->children_count=1;
			root=gp;
		}
	}
}

template<class T,bool use_pairs,class AL>
bool Octree<T,use_pairs,AL>::_remove_element_from_octant(Element *p_element,Octant *p_octant,Octant *p_limit) {

	bool octant_removed=false;

	while(true) {

		// check all exit conditions

		if (p_octant==p_limit) // reached limit, nothing to erase, exit
			return octant_removed;

		bool unpaired=false;

		if (use_pairs && p_octant->last_pass!=pass) {
			// check wether we should unpair stuff
			// always test pairable
			typename List<Element*,AL>::Element *E=p_octant->pairable_elements.front();
			while(E) {
				_pair_unreference( p_element,E->get() );
				E=E->next();
			}
			if (p_element->pairable) {
				// and always test non-pairable if element is pairable
				E=p_octant->elements.front();
				while(E) {
					_pair_unreference( p_element,E->get() );
					E=E->next();
				}
			}
			p_octant->last_pass=pass;
			unpaired=true;
		}

		bool removed=false;

		Octant *parent=p_octant->parent;

		if (p_octant->children_count==0 && p_octant->elements.empty() && p_octant->pairable_elements.empty()) {

			// erase octant

			if (p_octant==root) { // won't have a parent, just erase

				root=NULL;
			} else {
				ERR_FAIL_INDEX_V(p_octant->parent_index,8,octant_removed);

				parent->children[ p_octant->parent_index ]=NULL;
				parent->children_count--;
			}

			memdelete_allocator<Octant,AL>(p_octant);
			octant_count--;
			removed=true;
			octant_removed=true;
		}

		if (!removed && !unpaired)
			return octant_removed; // no reason to keep going up anymore! was already visited and was not removed

		p_octant=parent;

	}

	return octant_removed;
}

template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_unpair_element(Element *p_element,Octant *p_octant) {


	// always test pairable
	typename List<Element*,AL>::Element *E=p_octant->pairable_elements.front();
	while(E) {
		if (E->get()->last_pass!=pass) { // only remove ONE reference
			_pair_unreference( p_element,E->get() );
			E->get()->last_pass=pass;
		}
		E=E->next();
	}

	if (p_element->pairable) {
		// and always test non-pairable if element is pairable
		E=p_octant->elements.front();
		while(E) {
			if (E->get()->last_pass!=pass) { // only remove ONE reference
				_pair_unreference( p_element,E->get() );
				E->get()->last_pass=pass;
			}
			E=E->next();
		}
	}

	p_octant->last_pass=pass;

	if (p_octant->children_count==0)
		return; // small optimization for leafs

	for (int i=0;i<8;i++) {

		if (p_octant->children[i])
			_unpair_element(p_element,p_octant->children[i]);
	}
}

template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_pair_element(Element *p_element,Octant *p_octant) {

	// always test pairable

	typename List<Element*,AL>::Element *E=p_octant->pairable_elements.front();

	while(E) {

		if (E->get()->last_pass!=pass) { // only get ONE reference
			_pair_reference( p_element,E->get() );
			E->get()->last_pass=pass;
		}
		E=E->next();
	}

	if (p_element->pairable) {
		// and always test non-pairable if element is pairable
		E=p_octant->elements.front();
		while(E) {
			if (E->get()->last_pass!=pass) { // only get ONE reference
				_pair_reference( p_element,E->get() );
				E->get()->last_pass=pass;
			}
			E=E->next();
		}
	}
	p_octant->last_pass=pass;

	if (p_octant->children_count==0)
		return; // small optimization for leafs

	for (int i=0;i<8;i++) {

		if (p_octant->children[i])
			_pair_element(p_element,p_octant->children[i]);
	}
}

template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_remove_element(Element *p_element) {

	pass++; // will do a new pass for this

	typename List< typename Element::OctantOwner,AL >::Element *I=p_element->octant_owners.front();


	/* FIRST remove going up normally */
	for(;I;I=I->next()) {

		Octant *o=I->get().octant;

		if (!use_pairs) // small speedup
			o->elements.erase( I->get().E );

		_remove_element_from_octant( p_element, o  );

	}

	/* THEN remove going down */

	I=p_element->octant_owners.front();

	if (use_pairs) {

		for(;I;I=I->next()) {

			Octant *o=I->get().octant;

			// erase children pairs, they are erased ONCE even if repeated
			pass++;
			for (int i=0;i<8;i++) {

				if (o->children[i])
					_unpair_element(p_element,o->children[i]);
			}

			if (p_element->pairable)
				o->pairable_elements.erase( I->get().E );
			else
				o->elements.erase( I->get().E );

		}
	}

	p_element->octant_owners.clear();

	if(use_pairs) {

		int remaining=p_element->pair_list.size();
		//p_element->pair_list.clear();
		ERR_FAIL_COND( remaining );
	}

}

template<class T,bool use_pairs,class AL>
OctreeElementID Octree<T,use_pairs,AL>::create(T* p_userdata, const Rect3& p_aabb, int p_subindex,bool p_pairable,uint32_t p_pairable_type,uint32_t p_pairable_mask) {

	// check for AABB validity
#ifdef DEBUG_ENABLED
	ERR_FAIL_COND_V( p_aabb.pos.x > 1e15 || p_aabb.pos.x < -1e15, 0 );
	ERR_FAIL_COND_V( p_aabb.pos.y > 1e15 || p_aabb.pos.y < -1e15, 0 );
	ERR_FAIL_COND_V( p_aabb.pos.z > 1e15 || p_aabb.pos.z < -1e15, 0 );
	ERR_FAIL_COND_V( p_aabb.size.x > 1e15 || p_aabb.size.x < 0.0, 0 );
	ERR_FAIL_COND_V( p_aabb.size.y > 1e15 || p_aabb.size.y < 0.0, 0 );
	ERR_FAIL_COND_V( p_aabb.size.z > 1e15 || p_aabb.size.z < 0.0, 0 );
	ERR_FAIL_COND_V( Math::is_nan(p_aabb.size.x) , 0 );
	ERR_FAIL_COND_V( Math::is_nan(p_aabb.size.y) , 0 );
	ERR_FAIL_COND_V( Math::is_nan(p_aabb.size.z) , 0 );


#endif
	typename ElementMap::Element *E = element_map.insert(last_element_id++,
	Element());
	Element &e = E->get();

	e.aabb=p_aabb;
	e.userdata=p_userdata;
	e.subindex=p_subindex;
	e.last_pass=0;
	e.octree=this;
	e.pairable=p_pairable;
	e.pairable_type=p_pairable_type;
	e.pairable_mask=p_pairable_mask;
	e._id=last_element_id-1;

	if (!e.aabb.has_no_surface()) {
		_ensure_valid_root(p_aabb);
		_insert_element(&e,root);
		if (use_pairs)
			_element_check_pairs(&e);
	}

	return last_element_id-1;
}



template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::move(OctreeElementID p_id, const Rect3& p_aabb) {

#ifdef DEBUG_ENABLED
	// check for AABB validity
	ERR_FAIL_COND( p_aabb.pos.x > 1e15 || p_aabb.pos.x < -1e15 );
	ERR_FAIL_COND( p_aabb.pos.y > 1e15 || p_aabb.pos.y < -1e15 );
	ERR_FAIL_COND( p_aabb.pos.z > 1e15 || p_aabb.pos.z < -1e15 );
	ERR_FAIL_COND( p_aabb.size.x > 1e15 || p_aabb.size.x < 0.0 );
	ERR_FAIL_COND( p_aabb.size.y > 1e15 || p_aabb.size.y < 0.0 );
	ERR_FAIL_COND( p_aabb.size.z > 1e15 || p_aabb.size.z < 0.0 );
	ERR_FAIL_COND( Math::is_nan(p_aabb.size.x)  );
	ERR_FAIL_COND( Math::is_nan(p_aabb.size.y)  );
	ERR_FAIL_COND( Math::is_nan(p_aabb.size.z)  );
#endif
	typename ElementMap::Element *E = element_map.find(p_id);
	ERR_FAIL_COND(!E);
	Element &e = E->get();

#if 0

	pass++;
	if (!e.aabb.has_no_surface()) {
		_remove_element(&e);
	}

	e.aabb=p_aabb;

	if (!e.aabb.has_no_surface()) {
		_ensure_valid_root(p_aabb);

		_insert_element(&e,root);
		if (use_pairs)
			_element_check_pairs(&e);

	}

	_optimize();

#else

	bool old_has_surf=!e.aabb.has_no_surface();
	bool new_has_surf=!p_aabb.has_no_surface();

	if (old_has_surf!=new_has_surf) {


		if (old_has_surf) {
			_remove_element(&e); // removing
			e.common_parent=NULL;
			e.aabb=Rect3();
			_optimize();
		} else {
			_ensure_valid_root(p_aabb); // inserting
			e.common_parent=NULL;
			e.aabb=p_aabb;
			_insert_element(&e,root);
			if (use_pairs)
				_element_check_pairs(&e);

		}

		return;
	}

	if (!old_has_surf) // doing nothing
		return;

	// it still is enclosed in the same AABB it was assigned to
	if (e.container_aabb.encloses(p_aabb)) {

		e.aabb=p_aabb;
		if (use_pairs)
			_element_check_pairs(&e); // must check pairs anyway


		return;
	}

	Rect3 combined=e.aabb;
	combined.merge_with(p_aabb);
	_ensure_valid_root(combined);

	ERR_FAIL_COND( e.octant_owners.front()==NULL );

	/* FIND COMMON PARENT */

	List<typename Element::OctantOwner,AL> owners = e.octant_owners; // save the octant owners
	Octant *common_parent=e.common_parent;
	ERR_FAIL_COND(!common_parent);


	//src is now the place towards where insertion is going to happen
	pass++;

	while(common_parent && !common_parent->aabb.encloses(p_aabb))
		common_parent=common_parent->parent;

	ERR_FAIL_COND(!common_parent);

	//prepare for reinsert
	e.octant_owners.clear();
	e.common_parent=NULL;
	e.aabb=p_aabb;

	_insert_element(&e,common_parent); // reinsert from this point

	pass++;

	for(typename List<typename Element::OctantOwner,AL>::Element *E=owners.front();E;) {

		Octant *o=E->get().octant;
		typename List<typename Element::OctantOwner,AL>::Element *N=E->next();

		/*
		if (!use_pairs)
			o->elements.erase( E->get().E );
		*/

		if (use_pairs && e.pairable)
			o->pairable_elements.erase( E->get().E );
		else
			o->elements.erase( E->get().E );

		if (_remove_element_from_octant( &e, o, common_parent->parent  )) {

			owners.erase(E);
		}

		E=N;
	}


	if (use_pairs) {
		//unpair child elements in anything that survived
		for(typename List<typename Element::OctantOwner,AL>::Element *E=owners.front();E;E=E->next()) {

			Octant *o=E->get().octant;

			// erase children pairs, unref ONCE
			pass++;
			for (int i=0;i<8;i++) {

				if (o->children[i])
					_unpair_element(&e,o->children[i]);
			}

		}

		_element_check_pairs(&e);
	}


	_optimize();
#endif


}

template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::set_pairable(OctreeElementID p_id,bool p_pairable,uint32_t p_pairable_type,uint32_t p_pairable_mask) {

	typename ElementMap::Element *E = element_map.find(p_id);
	ERR_FAIL_COND(!E);

	Element &e = E->get();

	if (p_pairable == e.pairable && e.pairable_type==p_pairable_type && e.pairable_mask==p_pairable_mask)
		return; // no changes, return

	if (!e.aabb.has_no_surface()) {
		_remove_element(&e);
	}

	e.pairable=p_pairable;
	e.pairable_type=p_pairable_type;
	e.pairable_mask=p_pairable_mask;
	e.common_parent=NULL;

	if (!e.aabb.has_no_surface()) {
		_ensure_valid_root(e.aabb);
		_insert_element(&e,root);
		if (use_pairs)
			_element_check_pairs(&e);

	}
}


template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::erase(OctreeElementID p_id) {

	typename ElementMap::Element *E = element_map.find(p_id);
	ERR_FAIL_COND(!E);

	Element &e = E->get();

	if (!e.aabb.has_no_surface()) {

		_remove_element(&e);
	}

	element_map.erase(p_id);
	_optimize();
}

template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_cull_convex(Octant *p_octant,_CullConvexData *p_cull) {

	if (*p_cull->result_idx==p_cull->result_max)
		return; //pointless

	if (!p_octant->elements.empty()) {

		typename List< Element*,AL >::Element *I;
		I=p_octant->elements.front();

		for(;I;I=I->next()) {

			Element *e=I->get();

			if (e->last_pass==pass || (use_pairs && !(e->pairable_type&p_cull->mask)))
				continue;
			e->last_pass=pass;

			if (e->aabb.intersects_convex_shape(p_cull->planes,p_cull->plane_count)) {

				if (*p_cull->result_idx<p_cull->result_max) {
					p_cull->result_array[*p_cull->result_idx] = e->userdata;
					(*p_cull->result_idx)++;
				} else {

					return; // pointless to continue
				}
			}
		}
	}

	if (use_pairs && !p_octant->pairable_elements.empty()) {

		typename List< Element*,AL >::Element *I;
		I=p_octant->pairable_elements.front();

		for(;I;I=I->next()) {

			Element *e=I->get();

			if (e->last_pass==pass || (use_pairs && !(e->pairable_type&p_cull->mask)))
				continue;
			e->last_pass=pass;

			if (e->aabb.intersects_convex_shape(p_cull->planes,p_cull->plane_count)) {

				if (*p_cull->result_idx<p_cull->result_max) {

					p_cull->result_array[*p_cull->result_idx] = e->userdata;
					(*p_cull->result_idx)++;
				} else {

					return; // pointless to continue
				}
			}
		}
	}

	for (int i=0;i<8;i++) {

		if (p_octant->children[i] && p_octant->children[i]->aabb.intersects_convex_shape(p_cull->planes,p_cull->plane_count)) {
			_cull_convex(p_octant->children[i],p_cull);
		}
	}
}


template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_cull_AABB(Octant *p_octant,const Rect3& p_aabb, T** p_result_array,int *p_result_idx,int p_result_max,int *p_subindex_array,uint32_t p_mask) {

	if (*p_result_idx==p_result_max)
		return; //pointless

	if (!p_octant->elements.empty()) {

		typename List< Element*,AL >::Element *I;
		I=p_octant->elements.front();
		for(;I;I=I->next()) {

			Element *e=I->get();

			if (e->last_pass==pass || (use_pairs && !(e->pairable_type&p_mask)))
				continue;
			e->last_pass=pass;

			if (p_aabb.intersects_inclusive(e->aabb)) {

				if (*p_result_idx<p_result_max) {

					p_result_array[*p_result_idx] = e->userdata;
					if (p_subindex_array)
						p_subindex_array[*p_result_idx] = e->subindex;

					(*p_result_idx)++;
				} else {

					return; // pointless to continue
				}
			}
		}
	}

	if (use_pairs && !p_octant->pairable_elements.empty()) {

		typename List< Element*,AL >::Element *I;
		I=p_octant->pairable_elements.front();
		for(;I;I=I->next()) {

			Element *e=I->get();

			if (e->last_pass==pass || (use_pairs && !(e->pairable_type&p_mask)))
				continue;
			e->last_pass=pass;

			if (p_aabb.intersects_inclusive(e->aabb)) {

				if (*p_result_idx<p_result_max) {

					p_result_array[*p_result_idx] = e->userdata;
					if (p_subindex_array)
						p_subindex_array[*p_result_idx] = e->subindex;
					(*p_result_idx)++;
				} else {

					return; // pointless to continue
				}
			}
		}
	}

	for (int i=0;i<8;i++) {

		if (p_octant->children[i] && p_octant->children[i]->aabb.intersects_inclusive(p_aabb)) {
			_cull_AABB(p_octant->children[i],p_aabb, p_result_array,p_result_idx,p_result_max,p_subindex_array,p_mask);
		}
	}

}

template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_cull_segment(Octant *p_octant,const Vector3& p_from, const Vector3& p_to,T** p_result_array,int *p_result_idx,int p_result_max,int *p_subindex_array,uint32_t p_mask) {

	if (*p_result_idx==p_result_max)
		return; //pointless

	if (!p_octant->elements.empty()) {

		typename List< Element*,AL >::Element *I;
		I=p_octant->elements.front();
		for(;I;I=I->next()) {

			Element *e=I->get();

			if (e->last_pass==pass || (use_pairs && !(e->pairable_type&p_mask)))
				continue;
			e->last_pass=pass;

			if (e->aabb.intersects_segment(p_from,p_to)) {

				if (*p_result_idx<p_result_max) {

					p_result_array[*p_result_idx] = e->userdata;
					if (p_subindex_array)
						p_subindex_array[*p_result_idx] = e->subindex;
					(*p_result_idx)++;

				} else {

					return; // pointless to continue
				}
			}
		}
	}

	if (use_pairs && !p_octant->pairable_elements.empty()) {

		typename List< Element*,AL >::Element *I;
		I=p_octant->pairable_elements.front();
		for(;I;I=I->next()) {

			Element *e=I->get();

			if (e->last_pass==pass || (use_pairs && !(e->pairable_type&p_mask)))
				continue;

			e->last_pass=pass;

			if (e->aabb.intersects_segment(p_from,p_to)) {

				if (*p_result_idx<p_result_max) {

					p_result_array[*p_result_idx] = e->userdata;
					if (p_subindex_array)
						p_subindex_array[*p_result_idx] = e->subindex;

					(*p_result_idx)++;

				} else {

					return; // pointless to continue
				}
			}
		}
	}


	for (int i=0;i<8;i++) {

		if (p_octant->children[i] && p_octant->children[i]->aabb.intersects_segment(p_from,p_to)) {
			_cull_segment(p_octant->children[i],p_from,p_to, p_result_array,p_result_idx,p_result_max,p_subindex_array,p_mask);
		}
	}
}


template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::_cull_point(Octant *p_octant,const Vector3& p_point,T** p_result_array,int *p_result_idx,int p_result_max,int *p_subindex_array,uint32_t p_mask) {

	if (*p_result_idx==p_result_max)
		return; //pointless

	if (!p_octant->elements.empty()) {

		typename List< Element*,AL >::Element *I;
		I=p_octant->elements.front();
		for(;I;I=I->next()) {

			Element *e=I->get();

			if (e->last_pass==pass || (use_pairs && !(e->pairable_type&p_mask)))
				continue;
			e->last_pass=pass;

			if (e->aabb.has_point(p_point)) {

				if (*p_result_idx<p_result_max) {

					p_result_array[*p_result_idx] = e->userdata;
					if (p_subindex_array)
						p_subindex_array[*p_result_idx] = e->subindex;
					(*p_result_idx)++;

				} else {

					return; // pointless to continue
				}
			}
		}
	}

	if (use_pairs && !p_octant->pairable_elements.empty()) {

		typename List< Element*,AL >::Element *I;
		I=p_octant->pairable_elements.front();
		for(;I;I=I->next()) {

			Element *e=I->get();

			if (e->last_pass==pass || (use_pairs && !(e->pairable_type&p_mask)))
				continue;

			e->last_pass=pass;

			if (e->aabb.has_point(p_point)) {

				if (*p_result_idx<p_result_max) {

					p_result_array[*p_result_idx] = e->userdata;
					if (p_subindex_array)
						p_subindex_array[*p_result_idx] = e->subindex;

					(*p_result_idx)++;

				} else {

					return; // pointless to continue
				}
			}
		}
	}


	for (int i=0;i<8;i++) {

		//could be optimized..
		if (p_octant->children[i] && p_octant->children[i]->aabb.has_point(p_point)) {
			_cull_point(p_octant->children[i],p_point, p_result_array,p_result_idx,p_result_max,p_subindex_array,p_mask);
		}
	}
}

template<class T,bool use_pairs,class AL>
int Octree<T,use_pairs,AL>::cull_convex(const Vector<Plane>& p_convex,T** p_result_array,int p_result_max,uint32_t p_mask) {

	if (!root)
		return 0;

	int result_count=0;
	pass++;
	_CullConvexData cdata;
	cdata.planes=&p_convex[0];
	cdata.plane_count=p_convex.size();
	cdata.result_array=p_result_array;
	cdata.result_max=p_result_max;
	cdata.result_idx=&result_count;
	cdata.mask=p_mask;

	_cull_convex(root,&cdata);

	return result_count;
}



template<class T,bool use_pairs,class AL>
int Octree<T,use_pairs,AL>::cull_AABB(const Rect3& p_aabb,T** p_result_array,int p_result_max,int *p_subindex_array,uint32_t p_mask) {


	if (!root)
		return 0;

	int result_count=0;
	pass++;
	_cull_AABB(root,p_aabb,p_result_array,&result_count,p_result_max,p_subindex_array,p_mask);

	return result_count;
}


template<class T,bool use_pairs,class AL>
int Octree<T,use_pairs,AL>::cull_segment(const Vector3& p_from, const Vector3& p_to,T** p_result_array,int p_result_max,int *p_subindex_array,uint32_t p_mask) {

	if (!root)
		return 0;

	int result_count=0;
	pass++;
	_cull_segment(root,p_from,p_to,p_result_array,&result_count,p_result_max,p_subindex_array,p_mask);

	return result_count;

}

template<class T,bool use_pairs,class AL>
int Octree<T,use_pairs,AL>::cull_point(const Vector3& p_point,T** p_result_array,int p_result_max,int *p_subindex_array,uint32_t p_mask) {

	if (!root)
		return 0;

	int result_count=0;
	pass++;
	_cull_point(root,p_point,p_result_array,&result_count,p_result_max,p_subindex_array,p_mask);

	return result_count;

}


template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::set_pair_callback( PairCallback p_callback, void *p_userdata ) {

	pair_callback=p_callback;
	pair_callback_userdata=p_userdata;
}
template<class T,bool use_pairs,class AL>
void Octree<T,use_pairs,AL>::set_unpair_callback( UnpairCallback p_callback, void *p_userdata ) {

	unpair_callback=p_callback;
	unpair_callback_userdata=p_userdata;

}


template<class T,bool use_pairs,class AL>
Octree<T,use_pairs,AL>::Octree(real_t p_unit_size) {

	last_element_id=1;
	pass=1;
	unit_size=p_unit_size;
	root=NULL;

	octant_count=0;
	pair_count=0;

	pair_callback=NULL;
	unpair_callback=NULL;
	pair_callback_userdata=NULL;
	unpair_callback_userdata=NULL;




}




#endif