/*************************************************************************/
/*  space_2d_sw.cpp                                                      */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
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/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
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/*************************************************************************/
#include "space_2d_sw.h"
#include "collision_solver_2d_sw.h"
#include "physics_2d_server_sw.h"


_FORCE_INLINE_ static bool _match_object_type_query(CollisionObject2DSW *p_object, uint32_t p_layer_mask, uint32_t p_type_mask) {

	if ((p_object->get_layer_mask()&p_layer_mask)==0)
		return false;

	if (p_object->get_type()==CollisionObject2DSW::TYPE_AREA)
		return p_type_mask&Physics2DDirectSpaceState::TYPE_MASK_AREA;

	Body2DSW *body = static_cast<Body2DSW*>(p_object);

	return (1<<body->get_mode())&p_type_mask;

}


int Physics2DDirectSpaceStateSW::intersect_point(const Vector2& p_point,ShapeResult *r_results,int p_result_max,const Set<RID>& p_exclude,uint32_t p_layer_mask,uint32_t p_object_type_mask,bool p_pick_point) {

	if (p_result_max<=0)
		return 0;

	Rect2 aabb;
	aabb.pos=p_point-Vector2(0.00001,0.00001);
	aabb.size=Vector2(0.00002,0.00002);

	int amount = space->broadphase->cull_aabb(aabb,space->intersection_query_results,Space2DSW::INTERSECTION_QUERY_MAX,space->intersection_query_subindex_results);

	int cc=0;

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

		if (!_match_object_type_query(space->intersection_query_results[i],p_layer_mask,p_object_type_mask))
			continue;

		if (p_exclude.has( space->intersection_query_results[i]->get_self()))
			continue;

		const CollisionObject2DSW *col_obj=space->intersection_query_results[i];

		if (p_pick_point && !col_obj->is_pickable())
			continue;

		int shape_idx=space->intersection_query_subindex_results[i];

		Shape2DSW * shape = col_obj->get_shape(shape_idx);

		Vector2 local_point = (col_obj->get_transform() * col_obj->get_shape_transform(shape_idx)).affine_inverse().xform(p_point);

		if (!shape->contains_point(local_point))
			continue;

		if (cc>=p_result_max)
			continue;

		r_results[cc].collider_id=col_obj->get_instance_id();
		if (r_results[cc].collider_id!=0)
			r_results[cc].collider=ObjectDB::get_instance(r_results[cc].collider_id);
		r_results[cc].rid=col_obj->get_self();
		r_results[cc].shape=shape_idx;
		r_results[cc].metadata=col_obj->get_shape_metadata(shape_idx);

		cc++;
	}

	return cc;


}

bool Physics2DDirectSpaceStateSW::intersect_ray(const Vector2& p_from, const Vector2& p_to,RayResult &r_result,const Set<RID>& p_exclude,uint32_t p_layer_mask,uint32_t p_object_type_mask) {



	ERR_FAIL_COND_V(space->locked,false);

	Vector2 begin,end;
	Vector2 normal;
	begin=p_from;
	end=p_to;
	normal=(end-begin).normalized();

	int amount = space->broadphase->cull_segment(begin,end,space->intersection_query_results,Space2DSW::INTERSECTION_QUERY_MAX,space->intersection_query_subindex_results);

	//todo, create another array tha references results, compute AABBs and check closest point to ray origin, sort, and stop evaluating results when beyond first collision

	bool collided=false;
	Vector2 res_point,res_normal;
	int res_shape;
	const CollisionObject2DSW *res_obj;
	real_t min_d=1e10;


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

		if (!_match_object_type_query(space->intersection_query_results[i],p_layer_mask,p_object_type_mask))
			continue;

		if (p_exclude.has( space->intersection_query_results[i]->get_self()))
			continue;

		const CollisionObject2DSW *col_obj=space->intersection_query_results[i];

		int shape_idx=space->intersection_query_subindex_results[i];
		Matrix32 inv_xform = col_obj->get_shape_inv_transform(shape_idx) * col_obj->get_inv_transform();

		Vector2 local_from = inv_xform.xform(begin);
		Vector2 local_to = inv_xform.xform(end);

		/*local_from = col_obj->get_inv_transform().xform(begin);
		local_from = col_obj->get_shape_inv_transform(shape_idx).xform(local_from);

		local_to = col_obj->get_inv_transform().xform(end);
		local_to = col_obj->get_shape_inv_transform(shape_idx).xform(local_to);*/

		const Shape2DSW *shape = col_obj->get_shape(shape_idx);

		Vector2 shape_point,shape_normal;


		if (shape->intersect_segment(local_from,local_to,shape_point,shape_normal)) {



			Matrix32 xform = col_obj->get_transform() * col_obj->get_shape_transform(shape_idx);
			shape_point=xform.xform(shape_point);

			real_t ld = normal.dot(shape_point);


			if (ld<min_d) {

				min_d=ld;
				res_point=shape_point;
				res_normal=inv_xform.basis_xform_inv(shape_normal).normalized();
				res_shape=shape_idx;
				res_obj=col_obj;
				collided=true;
			}
		}

	}

	if (!collided)
		return false;


	r_result.collider_id=res_obj->get_instance_id();
	if (r_result.collider_id!=0)
		r_result.collider=ObjectDB::get_instance(r_result.collider_id);
	r_result.normal=res_normal;
	r_result.metadata=res_obj->get_shape_metadata(res_shape);
	r_result.position=res_point;
	r_result.rid=res_obj->get_self();
	r_result.shape=res_shape;

	return true;

}


int Physics2DDirectSpaceStateSW::intersect_shape(const RID& p_shape, const Matrix32& p_xform,const Vector2& p_motion,float p_margin,ShapeResult *r_results,int p_result_max,const Set<RID>& p_exclude,uint32_t p_layer_mask,uint32_t p_object_type_mask) {

	if (p_result_max<=0)
		return 0;

	Shape2DSW *shape = Physics2DServerSW::singletonsw->shape_owner.get(p_shape);
	ERR_FAIL_COND_V(!shape,0);

	Rect2 aabb = p_xform.xform(shape->get_aabb());
	aabb=aabb.grow(p_margin);

	int amount = space->broadphase->cull_aabb(aabb,space->intersection_query_results,p_result_max,space->intersection_query_subindex_results);

	int cc=0;

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

		if (!_match_object_type_query(space->intersection_query_results[i],p_layer_mask,p_object_type_mask))
			continue;

		if (p_exclude.has( space->intersection_query_results[i]->get_self()))
			continue;


		const CollisionObject2DSW *col_obj=space->intersection_query_results[i];
		int shape_idx=space->intersection_query_subindex_results[i];

		if (!CollisionSolver2DSW::solve(shape,p_xform,p_motion,col_obj->get_shape(shape_idx),col_obj->get_transform() * col_obj->get_shape_transform(shape_idx),Vector2(),NULL,NULL,NULL,p_margin))
			continue;

		r_results[cc].collider_id=col_obj->get_instance_id();
		if (r_results[cc].collider_id!=0)
			r_results[cc].collider=ObjectDB::get_instance(r_results[cc].collider_id);
		r_results[cc].rid=col_obj->get_self();
		r_results[cc].shape=shape_idx;
		r_results[cc].metadata=col_obj->get_shape_metadata(shape_idx);

		cc++;

	}

	return cc;

}



bool Physics2DDirectSpaceStateSW::cast_motion(const RID& p_shape, const Matrix32& p_xform,const Vector2& p_motion,float p_margin,float &p_closest_safe,float &p_closest_unsafe, const Set<RID>& p_exclude,uint32_t p_layer_mask,uint32_t p_object_type_mask) {



	Shape2DSW *shape = Physics2DServerSW::singletonsw->shape_owner.get(p_shape);
	ERR_FAIL_COND_V(!shape,false);

	Rect2 aabb = p_xform.xform(shape->get_aabb());
	aabb=aabb.merge(Rect2(aabb.pos+p_motion,aabb.size)); //motion
	aabb=aabb.grow(p_margin);

	//if (p_motion!=Vector2())
	//	print_line(p_motion);

	int amount = space->broadphase->cull_aabb(aabb,space->intersection_query_results,Space2DSW::INTERSECTION_QUERY_MAX,space->intersection_query_subindex_results);

	float best_safe=1;
	float best_unsafe=1;

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


		if (!_match_object_type_query(space->intersection_query_results[i],p_layer_mask,p_object_type_mask))
			continue;

		if (p_exclude.has( space->intersection_query_results[i]->get_self()))
			continue; //ignore excluded


		const CollisionObject2DSW *col_obj=space->intersection_query_results[i];
		int shape_idx=space->intersection_query_subindex_results[i];


		/*if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {

			const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);
			if (body->get_one_way_collision_direction()!=Vector2() && p_motion.dot(body->get_one_way_collision_direction())<=CMP_EPSILON) {
				print_line("failed in motion dir");
				continue;
			}
		}*/


		Matrix32 col_obj_xform = col_obj->get_transform() * col_obj->get_shape_transform(shape_idx);
		//test initial overlap, does it collide if going all the way?
		if (!CollisionSolver2DSW::solve(shape,p_xform,p_motion,col_obj->get_shape(shape_idx),col_obj_xform,Vector2() ,NULL,NULL,NULL,p_margin)) {
			continue;
		}


		//test initial overlap
		if (CollisionSolver2DSW::solve(shape,p_xform,Vector2(),col_obj->get_shape(shape_idx),col_obj_xform,Vector2() ,NULL,NULL,NULL,p_margin)) {

			if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {
				//if one way collision direction ignore initial overlap
				const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);
				if (body->get_one_way_collision_direction()!=Vector2()) {
					continue;
				}
			}

			return false;
		}


		//just do kinematic solving
		float low=0;
		float hi=1;
		Vector2 mnormal=p_motion.normalized();

		for(int i=0;i<8;i++) { //steps should be customizable..

			float ofs = (low+hi)*0.5;

			Vector2 sep=mnormal; //important optimization for this to work fast enough
			bool collided = CollisionSolver2DSW::solve(shape,p_xform,p_motion*ofs,col_obj->get_shape(shape_idx),col_obj_xform,Vector2(),NULL,NULL,&sep,p_margin);

			if (collided) {

				hi=ofs;
			} else {

				low=ofs;
			}
		}

		if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {

			const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);
			if (body->get_one_way_collision_direction()!=Vector2()) {

				Vector2 cd[2];
				Physics2DServerSW::CollCbkData cbk;
				cbk.max=1;
				cbk.amount=0;
				cbk.ptr=cd;
				cbk.valid_dir=body->get_one_way_collision_direction();
				cbk.valid_depth=body->get_one_way_collision_max_depth();

				Vector2 sep=mnormal; //important optimization for this to work fast enough
				bool collided = CollisionSolver2DSW::solve(shape,p_xform,p_motion*(hi+space->contact_max_allowed_penetration),col_obj->get_shape(shape_idx),col_obj_xform,Vector2(),Physics2DServerSW::_shape_col_cbk,&cbk,&sep,p_margin);
				if (!collided || cbk.amount==0) {
					continue;
				}

			}
		}


		if (low<best_safe) {
			best_safe=low;
			best_unsafe=hi;
		}

	}

	p_closest_safe=best_safe;
	p_closest_unsafe=best_unsafe;

	return true;


}


bool Physics2DDirectSpaceStateSW::collide_shape(RID p_shape, const Matrix32& p_shape_xform,const Vector2& p_motion,float p_margin,Vector2 *r_results,int p_result_max,int &r_result_count, const Set<RID>& p_exclude,uint32_t p_layer_mask,uint32_t p_object_type_mask) {


	if (p_result_max<=0)
		return 0;

	Shape2DSW *shape = Physics2DServerSW::singletonsw->shape_owner.get(p_shape);
	ERR_FAIL_COND_V(!shape,0);

	Rect2 aabb = p_shape_xform.xform(shape->get_aabb());
	aabb=aabb.merge(Rect2(aabb.pos+p_motion,aabb.size)); //motion
	aabb=aabb.grow(p_margin);

	int amount = space->broadphase->cull_aabb(aabb,space->intersection_query_results,Space2DSW::INTERSECTION_QUERY_MAX,space->intersection_query_subindex_results);

	bool collided=false;
	r_result_count=0;

	Physics2DServerSW::CollCbkData cbk;
	cbk.max=p_result_max;
	cbk.amount=0;
	cbk.ptr=r_results;
	CollisionSolver2DSW::CallbackResult cbkres=NULL;

	Physics2DServerSW::CollCbkData *cbkptr=NULL;
	if (p_result_max>0) {
		cbkptr=&cbk;
		cbkres=Physics2DServerSW::_shape_col_cbk;
	}


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

		if (!_match_object_type_query(space->intersection_query_results[i],p_layer_mask,p_object_type_mask))
			continue;

		const CollisionObject2DSW *col_obj=space->intersection_query_results[i];
		int shape_idx=space->intersection_query_subindex_results[i];

		if (p_exclude.has( col_obj->get_self() ))
			continue;
		if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {

			const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);
			cbk.valid_dir=body->get_one_way_collision_direction();
			cbk.valid_depth=body->get_one_way_collision_max_depth();
		} else {
			cbk.valid_dir=Vector2();
			cbk.valid_depth=0;
		}

		if (CollisionSolver2DSW::solve(shape,p_shape_xform,p_motion,col_obj->get_shape(shape_idx),col_obj->get_transform() * col_obj->get_shape_transform(shape_idx),Vector2(),cbkres,cbkptr,NULL,p_margin)) {
			collided=p_result_max==0 || cbk.amount>0;
		}

	}


	r_result_count=cbk.amount;

	return collided;
}


struct _RestCallbackData2D {

	const CollisionObject2DSW *object;
	const CollisionObject2DSW *best_object;
	int shape;
	int best_shape;
	Vector2 best_contact;
	Vector2 best_normal;
	float best_len;
	Vector2 valid_dir;
	float valid_depth;
};

static void _rest_cbk_result(const Vector2& p_point_A,const Vector2& p_point_B,void *p_userdata) {


	_RestCallbackData2D *rd=(_RestCallbackData2D*)p_userdata;

	if (rd->valid_dir!=Vector2()) {

		if (rd->valid_dir!=Vector2()) {
			if (p_point_A.distance_squared_to(p_point_B)>rd->valid_depth*rd->valid_depth)
				return;
			if (rd->valid_dir.dot((p_point_A-p_point_B).normalized())<Math_PI*0.25)
				return;
		}

	}

	Vector2 contact_rel = p_point_B - p_point_A;
	float len = contact_rel.length();
	if (len <= rd->best_len)
		return;


	rd->best_len=len;
	rd->best_contact=p_point_B;
	rd->best_normal=contact_rel/len;
	rd->best_object=rd->object;
	rd->best_shape=rd->shape;


}


bool Physics2DDirectSpaceStateSW::rest_info(RID p_shape, const Matrix32& p_shape_xform,const Vector2& p_motion,float p_margin,ShapeRestInfo *r_info, const Set<RID>& p_exclude,uint32_t p_layer_mask,uint32_t p_object_type_mask) {


	Shape2DSW *shape = Physics2DServerSW::singletonsw->shape_owner.get(p_shape);
	ERR_FAIL_COND_V(!shape,0);

	Rect2 aabb = p_shape_xform.xform(shape->get_aabb());
	aabb=aabb.merge(Rect2(aabb.pos+p_motion,aabb.size)); //motion
	aabb=aabb.grow(p_margin);

	int amount = space->broadphase->cull_aabb(aabb,space->intersection_query_results,Space2DSW::INTERSECTION_QUERY_MAX,space->intersection_query_subindex_results);

	_RestCallbackData2D rcd;
	rcd.best_len=0;
	rcd.best_object=NULL;
	rcd.best_shape=0;

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


		if (!_match_object_type_query(space->intersection_query_results[i],p_layer_mask,p_object_type_mask))
			continue;

		const CollisionObject2DSW *col_obj=space->intersection_query_results[i];
		int shape_idx=space->intersection_query_subindex_results[i];

		if (p_exclude.has( col_obj->get_self() ))
			continue;

		if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {

			const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);
			rcd.valid_dir=body->get_one_way_collision_direction();
			rcd.valid_depth=body->get_one_way_collision_max_depth();
		} else {
			rcd.valid_dir=Vector2();
			rcd.valid_depth=0;
		}


		rcd.object=col_obj;
		rcd.shape=shape_idx;
		bool sc = CollisionSolver2DSW::solve(shape,p_shape_xform,p_motion,col_obj->get_shape(shape_idx),col_obj->get_transform() * col_obj->get_shape_transform(shape_idx),Vector2() ,_rest_cbk_result,&rcd,NULL,p_margin);
		if (!sc)
			continue;


	}

	if (rcd.best_len==0)
		return false;

	r_info->collider_id=rcd.best_object->get_instance_id();
	r_info->shape=rcd.best_shape;
	r_info->normal=rcd.best_normal;
	r_info->point=rcd.best_contact;
	r_info->rid=rcd.best_object->get_self();
	r_info->metadata=rcd.best_object->get_shape_metadata(rcd.best_shape);
	if (rcd.best_object->get_type()==CollisionObject2DSW::TYPE_BODY) {

		const Body2DSW *body = static_cast<const Body2DSW*>(rcd.best_object);
		Vector2 rel_vec = r_info->point-body->get_transform().get_origin();
		r_info->linear_velocity = Vector2(-body->get_angular_velocity() * rel_vec.y, body->get_angular_velocity() * rel_vec.x) + body->get_linear_velocity();

	} else {
		r_info->linear_velocity=Vector2();
	}

	return true;
}


Physics2DDirectSpaceStateSW::Physics2DDirectSpaceStateSW() {


	space=NULL;
}


////////////////////////////////////////////////////////////////////////////////////////////////////////////




int Space2DSW::_cull_aabb_for_body(Body2DSW *p_body,const Rect2& p_aabb) {


	int amount = broadphase->cull_aabb(p_aabb,intersection_query_results,INTERSECTION_QUERY_MAX,intersection_query_subindex_results);

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

		bool keep=true;

		if (intersection_query_results[i]==p_body)
			keep=false;
		else if (intersection_query_results[i]->get_type()==CollisionObject2DSW::TYPE_AREA)
			keep=false;
		else if ((static_cast<Body2DSW*>(intersection_query_results[i])->test_collision_mask(p_body))==0)
			keep=false;
		else if (static_cast<Body2DSW*>(intersection_query_results[i])->has_exception(p_body->get_self()) || p_body->has_exception(intersection_query_results[i]->get_self()))
			keep=false;
		else if (static_cast<Body2DSW*>(intersection_query_results[i])->is_shape_set_as_trigger(intersection_query_subindex_results[i]))
			keep=false;

		if (!keep) {

			if (i<amount-1) {
				SWAP(intersection_query_results[i],intersection_query_results[amount-1]);
				SWAP(intersection_query_subindex_results[i],intersection_query_subindex_results[amount-1]);

			}

			amount--;
			i--;

		}
	}

	return amount;
}

bool Space2DSW::test_body_motion(Body2DSW *p_body, const Matrix32 &p_from, const Vector2&p_motion, float p_margin, Physics2DServer::MotionResult *r_result) {

	//give me back regular physics engine logic
	//this is madness
	//and most people using this function will think
	//what it does is simpler than using physics
	//this took about a week to get right..
	//but is it right? who knows at this point..

	if (r_result) {
		r_result->collider_id=0;
		r_result->collider_shape=0;

	}
	Rect2 body_aabb;

	for(int i=0;i<p_body->get_shape_count();i++) {

		if (i==0)
			body_aabb=p_body->get_shape_aabb(i);
		else
			body_aabb=body_aabb.merge(p_body->get_shape_aabb(i));
	}

	body_aabb=body_aabb.grow(p_margin);

	Matrix32 body_transform = p_from;

	{
		//STEP 1, FREE BODY IF STUCK

		const int max_results = 32;
		int recover_attempts=4;
		Vector2 sr[max_results*2];

		do {

			Physics2DServerSW::CollCbkData cbk;
			cbk.max=max_results;
			cbk.amount=0;
			cbk.ptr=sr;


			CollisionSolver2DSW::CallbackResult cbkres=NULL;

			Physics2DServerSW::CollCbkData *cbkptr=NULL;
			cbkptr=&cbk;
			cbkres=Physics2DServerSW::_shape_col_cbk;

			bool collided=false;

			int amount = _cull_aabb_for_body(p_body,body_aabb);

			for(int j=0;j<p_body->get_shape_count();j++) {
				if (p_body->is_shape_set_as_trigger(j))
					continue;

				Matrix32 body_shape_xform = body_transform * p_body->get_shape_transform(j);
				Shape2DSW *body_shape = p_body->get_shape(j);
				for(int i=0;i<amount;i++) {

					const CollisionObject2DSW *col_obj=intersection_query_results[i];
					int shape_idx=intersection_query_subindex_results[i];

					if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {

						const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);

						Vector2 cdir = body->get_one_way_collision_direction();
						//if (cdir!=Vector2() && p_motion.dot(cdir)<0)
						//	continue;

						cbk.valid_dir=cdir;
						cbk.valid_depth=body->get_one_way_collision_max_depth();
					} else {
						cbk.valid_dir=Vector2();
						cbk.valid_depth=0;
					}

					if (CollisionSolver2DSW::solve(body_shape,body_shape_xform,Vector2(),col_obj->get_shape(shape_idx),col_obj->get_transform() * col_obj->get_shape_transform(shape_idx),Vector2(),cbkres,cbkptr,NULL,p_margin)) {
						collided=cbk.amount>0;
					}
				}
			}


			if (!collided)
				break;

			Vector2 recover_motion;

			for(int i=0;i<cbk.amount;i++) {

				Vector2 a = sr[i*2+0];
				Vector2 b = sr[i*2+1];

#if 0
				Vector2 rel = b-a;
				float d = rel.length();
				if (d==0)
					continue;

				Vector2 n = rel/d;
				float traveled = n.dot(recover_motion);
				a+=n*traveled;

#endif
			//	float d = a.distance_to(b);

				//if (d<margin)
				///	continue;
				recover_motion+=(b-a)*0.4;
			}

			if (recover_motion==Vector2()) {
				collided=false;
				break;
			}

			body_transform.elements[2]+=recover_motion;
			body_aabb.pos+=recover_motion;

			recover_attempts--;

		} while (recover_attempts);
	}



	float safe = 1.0;
	float unsafe = 1.0;
	int best_shape=-1;

	{
		// STEP 2 ATTEMPT MOTION

		Rect2 motion_aabb=body_aabb;
		motion_aabb.pos+=p_motion;
		motion_aabb=motion_aabb.merge(body_aabb);

		int amount = _cull_aabb_for_body(p_body,motion_aabb);

		for(int j=0;j<p_body->get_shape_count();j++) {

			if (p_body->is_shape_set_as_trigger(j))
				continue;

			Matrix32 body_shape_xform = body_transform * p_body->get_shape_transform(j);
			Shape2DSW *body_shape = p_body->get_shape(j);

			bool stuck=false;

			float best_safe=1;
			float best_unsafe=1;

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

				const CollisionObject2DSW *col_obj=intersection_query_results[i];
				int shape_idx=intersection_query_subindex_results[i];


				Matrix32 col_obj_xform = col_obj->get_transform() * col_obj->get_shape_transform(shape_idx);
				//test initial overlap, does it collide if going all the way?
				if (!CollisionSolver2DSW::solve(body_shape,body_shape_xform,p_motion,col_obj->get_shape(shape_idx),col_obj_xform,Vector2() ,NULL,NULL,NULL,0)) {
					continue;
				}


				//test initial overlap
				if (CollisionSolver2DSW::solve(body_shape,body_shape_xform,Vector2(),col_obj->get_shape(shape_idx),col_obj_xform,Vector2() ,NULL,NULL,NULL,0)) {

					if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {
						//if one way collision direction ignore initial overlap
						const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);
						if (body->get_one_way_collision_direction()!=Vector2()) {
							continue;
						}
					}

					stuck=true;
					break;
				}


				//just do kinematic solving
				float low=0;
				float hi=1;
				Vector2 mnormal=p_motion.normalized();

				for(int i=0;i<8;i++) { //steps should be customizable..

					float ofs = (low+hi)*0.5;

					Vector2 sep=mnormal; //important optimization for this to work fast enough
					bool collided = CollisionSolver2DSW::solve(body_shape,body_shape_xform,p_motion*ofs,col_obj->get_shape(shape_idx),col_obj_xform,Vector2(),NULL,NULL,&sep,0);

					if (collided) {

						hi=ofs;
					} else {

						low=ofs;
					}
				}

				if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {

					const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);
					if (body->get_one_way_collision_direction()!=Vector2()) {

						Vector2 cd[2];
						Physics2DServerSW::CollCbkData cbk;
						cbk.max=1;
						cbk.amount=0;
						cbk.ptr=cd;
						cbk.valid_dir=body->get_one_way_collision_direction();
						cbk.valid_depth=body->get_one_way_collision_max_depth();

						Vector2 sep=mnormal; //important optimization for this to work fast enough
						bool collided = CollisionSolver2DSW::solve(body_shape,body_shape_xform,p_motion*(hi+contact_max_allowed_penetration),col_obj->get_shape(shape_idx),col_obj_xform,Vector2(),Physics2DServerSW::_shape_col_cbk,&cbk,&sep,0);
						if (!collided || cbk.amount==0) {
							continue;
						}

					}
				}


				if (low<best_safe) {
					best_safe=low;
					best_unsafe=hi;
				}
			}

			if (stuck) {

				safe=0;
				unsafe=0;
				best_shape=j; //sadly it's the best
				break;
			}
			if (best_safe==1.0) {
				continue;
			}
			if (best_safe < safe) {

				safe=best_safe;
				unsafe=best_unsafe;
				best_shape=j;
			}
		}
	}

	bool collided=false;
	if (safe>=1) {
		//not collided
		collided=false;
		if (r_result) {

			r_result->motion=p_motion;
			r_result->remainder=Vector2();			
			r_result->motion+=(body_transform.elements[2]-p_from.elements[2]);
		}

	} else {

		//it collided, let's get the rest info in unsafe advance
		Matrix32 ugt = body_transform;
		ugt.elements[2]+=p_motion*unsafe;

		_RestCallbackData2D rcd;
		rcd.best_len=0;
		rcd.best_object=NULL;
		rcd.best_shape=0;

		Matrix32 body_shape_xform = ugt * p_body->get_shape_transform(best_shape);
		Shape2DSW *body_shape = p_body->get_shape(best_shape);

		body_aabb.pos+=p_motion*unsafe;

		int amount = _cull_aabb_for_body(p_body,body_aabb);


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


			const CollisionObject2DSW *col_obj=intersection_query_results[i];
			int shape_idx=intersection_query_subindex_results[i];

			if (col_obj->get_type()==CollisionObject2DSW::TYPE_BODY) {

				const Body2DSW *body=static_cast<const Body2DSW*>(col_obj);
				rcd.valid_dir=body->get_one_way_collision_direction();
				rcd.valid_depth=body->get_one_way_collision_max_depth();
			} else {
				rcd.valid_dir=Vector2();
				rcd.valid_depth=0;
			}


			rcd.object=col_obj;
			rcd.shape=shape_idx;
			bool sc = CollisionSolver2DSW::solve(body_shape,body_shape_xform,Vector2(),col_obj->get_shape(shape_idx),col_obj->get_transform() * col_obj->get_shape_transform(shape_idx),Vector2() ,_rest_cbk_result,&rcd,NULL,p_margin);
			if (!sc)
				continue;

		}

		if (rcd.best_len!=0) {

			if (r_result) {
				r_result->collider=rcd.best_object->get_self();
				r_result->collider_id=rcd.best_object->get_instance_id();
				r_result->collider_shape=rcd.best_shape;
				r_result->collision_normal=rcd.best_normal;
				r_result->collision_point=rcd.best_contact;
				r_result->collider_metadata=rcd.best_object->get_shape_metadata(rcd.best_shape);

				const Body2DSW *body = static_cast<const Body2DSW*>(rcd.best_object);
				Vector2 rel_vec = r_result->collision_point-body->get_transform().get_origin();
				r_result->collider_velocity = Vector2(-body->get_angular_velocity() * rel_vec.y, body->get_angular_velocity() * rel_vec.x) + body->get_linear_velocity();

				r_result->motion=safe*p_motion;
				r_result->remainder=p_motion - safe * p_motion;
				r_result->motion+=(body_transform.elements[2]-p_from.elements[2]);

			}

			collided=true;
		} else {
			if (r_result) {

				r_result->motion=p_motion;
				r_result->remainder=Vector2();
				r_result->motion+=(body_transform.elements[2]-p_from.elements[2]);
			}

			collided=false;

		}
	}

	return collided;


#if 0
	//give me back regular physics engine logic
	//this is madness
	//and most people using this function will think
	//what it does is simpler than using physics
	//this took about a week to get right..
	//but is it right? who knows at this point..


	colliding=false;
	ERR_FAIL_COND_V(!is_inside_tree(),Vector2());
	Physics2DDirectSpaceState *dss = Physics2DServer::get_singleton()->space_get_direct_state(get_world_2d()->get_space());
	ERR_FAIL_COND_V(!dss,Vector2());
	const int max_shapes=32;
	Vector2 sr[max_shapes*2];
	int res_shapes;

	Set<RID> exclude;
	exclude.insert(get_rid());


	//recover first
	int recover_attempts=4;

	bool collided=false;
	uint32_t mask=0;
	if (collide_static)
		mask|=Physics2DDirectSpaceState::TYPE_MASK_STATIC_BODY;
	if (collide_kinematic)
		mask|=Physics2DDirectSpaceState::TYPE_MASK_KINEMATIC_BODY;
	if (collide_rigid)
		mask|=Physics2DDirectSpaceState::TYPE_MASK_RIGID_BODY;
	if (collide_character)
		mask|=Physics2DDirectSpaceState::TYPE_MASK_CHARACTER_BODY;

//	print_line("motion: "+p_motion+" margin: "+rtos(margin));

	//print_line("margin: "+rtos(margin));
	do {

		//motion recover
		for(int i=0;i<get_shape_count();i++) {

			if (is_shape_set_as_trigger(i))
				continue;
			if (dss->collide_shape(get_shape(i)->get_rid(), get_global_transform() * get_shape_transform(i),Vector2(),margin,sr,max_shapes,res_shapes,exclude,get_layer_mask(),mask))
				collided=true;

		}

		if (!collided)
			break;

		Vector2 recover_motion;

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

			Vector2 a = sr[i*2+0];
			Vector2 b = sr[i*2+1];

			float d = a.distance_to(b);

			//if (d<margin)
			///	continue;
			recover_motion+=(b-a)*0.4;
		}

		if (recover_motion==Vector2()) {
			collided=false;
			break;
		}

		Matrix32 gt = get_global_transform();
		gt.elements[2]+=recover_motion;
		set_global_transform(gt);

		recover_attempts--;

	} while (recover_attempts);


	//move second
	float safe = 1.0;
	float unsafe = 1.0;
	int best_shape=-1;

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

		if (is_shape_set_as_trigger(i))
			continue;

		float lsafe,lunsafe;
		bool valid = dss->cast_motion(get_shape(i)->get_rid(), get_global_transform() * get_shape_transform(i), p_motion, 0,lsafe,lunsafe,exclude,get_layer_mask(),mask);
		//print_line("shape: "+itos(i)+" travel:"+rtos(ltravel));
		if (!valid) {

			safe=0;
			unsafe=0;
			best_shape=i; //sadly it's the best
			break;
		}
		if (lsafe==1.0) {
			continue;
		}
		if (lsafe < safe) {

			safe=lsafe;
			unsafe=lunsafe;
			best_shape=i;
		}
	}


	//print_line("best shape: "+itos(best_shape)+" motion "+p_motion);

	if (safe>=1) {
		//not collided
		colliding=false;
	} else {

		//it collided, let's get the rest info in unsafe advance
		Matrix32 ugt = get_global_transform();
		ugt.elements[2]+=p_motion*unsafe;
		Physics2DDirectSpaceState::ShapeRestInfo rest_info;
		bool c2 = dss->rest_info(get_shape(best_shape)->get_rid(), ugt*get_shape_transform(best_shape), Vector2(), margin,&rest_info,exclude,get_layer_mask(),mask);
		if (!c2) {
			//should not happen, but floating point precision is so weird..

			colliding=false;
		} else {


			//print_line("Travel: "+rtos(travel));
			colliding=true;
			collision=rest_info.point;
			normal=rest_info.normal;
			collider=rest_info.collider_id;
			collider_vel=rest_info.linear_velocity;
			collider_shape=rest_info.shape;
			collider_metadata=rest_info.metadata;
		}

	}

	Vector2 motion=p_motion*safe;
	Matrix32 gt = get_global_transform();
	gt.elements[2]+=motion;
	set_global_transform(gt);

	return p_motion-motion;

#endif
	return false;
}




void* Space2DSW::_broadphase_pair(CollisionObject2DSW *A,int p_subindex_A,CollisionObject2DSW *B,int p_subindex_B,void *p_self) {


	CollisionObject2DSW::Type type_A=A->get_type();
	CollisionObject2DSW::Type type_B=B->get_type();
	if (type_A>type_B) {

		SWAP(A,B);
		SWAP(p_subindex_A,p_subindex_B);
		SWAP(type_A,type_B);
	}

	Space2DSW *self = (Space2DSW*)p_self;
	self->collision_pairs++;

	if (type_A==CollisionObject2DSW::TYPE_AREA) {

		Area2DSW *area=static_cast<Area2DSW*>(A);
		if (type_B==CollisionObject2DSW::TYPE_AREA) {

			Area2DSW *area_b=static_cast<Area2DSW*>(B);
			Area2Pair2DSW *area2_pair = memnew(Area2Pair2DSW(area_b,p_subindex_B,area,p_subindex_A) );
			return area2_pair;
		} else {

			Body2DSW *body=static_cast<Body2DSW*>(B);
			AreaPair2DSW *area_pair = memnew(AreaPair2DSW(body,p_subindex_B,area,p_subindex_A) );
			return area_pair;
		}


	} else {


		BodyPair2DSW *b = memnew( BodyPair2DSW((Body2DSW*)A,p_subindex_A,(Body2DSW*)B,p_subindex_B) );
		return b;

	}

	return NULL;
}

void Space2DSW::_broadphase_unpair(CollisionObject2DSW *A,int p_subindex_A,CollisionObject2DSW *B,int p_subindex_B,void *p_data,void *p_self) {


	Space2DSW *self = (Space2DSW*)p_self;
	self->collision_pairs--;
	Constraint2DSW *c = (Constraint2DSW*)p_data;
	memdelete(c);
}


const SelfList<Body2DSW>::List& Space2DSW::get_active_body_list() const {

	return active_list;
}
void Space2DSW::body_add_to_active_list(SelfList<Body2DSW>* p_body) {

	active_list.add(p_body);
}
void Space2DSW::body_remove_from_active_list(SelfList<Body2DSW>* p_body) {

	active_list.remove(p_body);

}

void Space2DSW::body_add_to_inertia_update_list(SelfList<Body2DSW>* p_body) {


	inertia_update_list.add(p_body);
}

void Space2DSW::body_remove_from_inertia_update_list(SelfList<Body2DSW>* p_body) {

	inertia_update_list.remove(p_body);
}

BroadPhase2DSW *Space2DSW::get_broadphase() {

	return broadphase;
}

void Space2DSW::add_object(CollisionObject2DSW *p_object) {

	ERR_FAIL_COND( objects.has(p_object) );
	objects.insert(p_object);
}

void Space2DSW::remove_object(CollisionObject2DSW *p_object) {

	ERR_FAIL_COND( !objects.has(p_object) );
	objects.erase(p_object);
}

const Set<CollisionObject2DSW*> &Space2DSW::get_objects() const {

	return objects;
}

void Space2DSW::body_add_to_state_query_list(SelfList<Body2DSW>* p_body) {

	state_query_list.add(p_body);
}
void Space2DSW::body_remove_from_state_query_list(SelfList<Body2DSW>* p_body) {

	state_query_list.remove(p_body);
}

void Space2DSW::area_add_to_monitor_query_list(SelfList<Area2DSW>* p_area) {

	monitor_query_list.add(p_area);
}
void Space2DSW::area_remove_from_monitor_query_list(SelfList<Area2DSW>* p_area) {

	monitor_query_list.remove(p_area);
}

void Space2DSW::area_add_to_moved_list(SelfList<Area2DSW>* p_area) {

	area_moved_list.add(p_area);
}

void Space2DSW::area_remove_from_moved_list(SelfList<Area2DSW>* p_area) {

	area_moved_list.remove(p_area);
}

const SelfList<Area2DSW>::List& Space2DSW::get_moved_area_list() const {

	return area_moved_list;
}


void Space2DSW::call_queries() {

	while(state_query_list.first()) {

		Body2DSW * b = state_query_list.first()->self();
		b->call_queries();
		state_query_list.remove(state_query_list.first());
	}

	while(monitor_query_list.first()) {

		Area2DSW * a = monitor_query_list.first()->self();
		a->call_queries();
		monitor_query_list.remove(monitor_query_list.first());
	}

}

void Space2DSW::setup() {

	contact_debug_count=0;

	while(inertia_update_list.first()) {
		inertia_update_list.first()->self()->update_inertias();
		inertia_update_list.remove(inertia_update_list.first());
	}


}

void Space2DSW::update() {

	broadphase->update();

}


void Space2DSW::set_param(Physics2DServer::SpaceParameter p_param, real_t p_value) {

	switch(p_param) {

		case Physics2DServer::SPACE_PARAM_CONTACT_RECYCLE_RADIUS: contact_recycle_radius=p_value; break;
		case Physics2DServer::SPACE_PARAM_CONTACT_MAX_SEPARATION: contact_max_separation=p_value; break;
		case Physics2DServer::SPACE_PARAM_BODY_MAX_ALLOWED_PENETRATION: contact_max_allowed_penetration=p_value; break;
		case Physics2DServer::SPACE_PARAM_BODY_LINEAR_VELOCITY_SLEEP_TRESHOLD: body_linear_velocity_sleep_treshold=p_value; break;
		case Physics2DServer::SPACE_PARAM_BODY_ANGULAR_VELOCITY_SLEEP_TRESHOLD: body_angular_velocity_sleep_treshold=p_value; break;
		case Physics2DServer::SPACE_PARAM_BODY_TIME_TO_SLEEP: body_time_to_sleep=p_value; break;
		case Physics2DServer::SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS: constraint_bias=p_value; break;
	}
}

real_t Space2DSW::get_param(Physics2DServer::SpaceParameter p_param) const {

	switch(p_param) {

		case Physics2DServer::SPACE_PARAM_CONTACT_RECYCLE_RADIUS: return contact_recycle_radius;
		case Physics2DServer::SPACE_PARAM_CONTACT_MAX_SEPARATION: return contact_max_separation;
		case Physics2DServer::SPACE_PARAM_BODY_MAX_ALLOWED_PENETRATION: return contact_max_allowed_penetration;
		case Physics2DServer::SPACE_PARAM_BODY_LINEAR_VELOCITY_SLEEP_TRESHOLD: return body_linear_velocity_sleep_treshold;
		case Physics2DServer::SPACE_PARAM_BODY_ANGULAR_VELOCITY_SLEEP_TRESHOLD: return body_angular_velocity_sleep_treshold;
		case Physics2DServer::SPACE_PARAM_BODY_TIME_TO_SLEEP: return body_time_to_sleep;
		case Physics2DServer::SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS: return constraint_bias;
	}
	return 0;
}

void Space2DSW::lock() {

	locked=true;
}

void Space2DSW::unlock() {

	locked=false;
}

bool Space2DSW::is_locked() const {

	return locked;
}

Physics2DDirectSpaceStateSW *Space2DSW::get_direct_state() {

	return direct_access;
}

Space2DSW::Space2DSW() {


	collision_pairs=0;
	active_objects=0;
	island_count=0;

	contact_debug_count=0;

	locked=false;
	contact_recycle_radius=1.0;
	contact_max_separation=1.5;
	contact_max_allowed_penetration= 0.3;

	constraint_bias = 0.2;
	body_linear_velocity_sleep_treshold=GLOBAL_DEF("physics_2d/sleep_threashold_linear",2.0);
	body_angular_velocity_sleep_treshold=GLOBAL_DEF("physics_2d/sleep_threshold_angular",(8.0 / 180.0 * Math_PI));
	body_time_to_sleep=GLOBAL_DEF("physics_2d/time_before_sleep",0.5);


	broadphase = BroadPhase2DSW::create_func();
	broadphase->set_pair_callback(_broadphase_pair,this);
	broadphase->set_unpair_callback(_broadphase_unpair,this);
	area=NULL;

	direct_access = memnew( Physics2DDirectSpaceStateSW );
	direct_access->space=this;


	for(int i=0;i<ELAPSED_TIME_MAX;i++)
		elapsed_time[i]=0;

}

Space2DSW::~Space2DSW() {

	memdelete(broadphase);
	memdelete( direct_access );
}