/*************************************************************************/
/*  body_pair_sw.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   */
/* 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:                                             */
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/* 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.*/
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/*************************************************************************/
#ifndef BODY_PAIR_SW_H
#define BODY_PAIR_SW_H

#include "body_sw.h"
#include "constraint_sw.h"

class BodyPairSW : public ConstraintSW {
	enum {

		MAX_CONTACTS=4
	};

	union {
		struct {
			BodySW *A;
			BodySW *B;
		};

		BodySW *_arr[2];
	};

	int shape_A;
	int shape_B;


	struct Contact {

		Vector3 position;
		Vector3 normal;
		Vector3 local_A, local_B;
		real_t acc_normal_impulse;	// accumulated normal impulse (Pn)
		Vector3 acc_tangent_impulse;	// accumulated tangent impulse (Pt)
		real_t acc_bias_impulse;	// accumulated normal impulse for position bias (Pnb)
		real_t mass_normal;
		real_t bias;

		real_t depth;
		bool active;
		Vector3 rA,rB;
	};

	Vector3 offset_B; //use local A coordinates to avoid numerical issues on collision detection

	Vector3 sep_axis;
	Contact contacts[MAX_CONTACTS];
	int contact_count;
	bool collided;
	int cc;


	static void _contact_added_callback(const Vector3& p_point_A,const Vector3& p_point_B,void *p_userdata);

	void contact_added_callback(const Vector3& p_point_A,const Vector3& p_point_B);

	void validate_contacts();

	SpaceSW *space;

public:

	bool setup(float p_step);
	void solve(float p_step);

	BodyPairSW(BodySW *p_A, int p_shape_A,BodySW *p_B, int p_shape_B);
	~BodyPairSW();

};

#endif // BODY_PAIR__SW_H