/*************************************************************************/
/*  body_pair_2d_sw.h                                                    */
/*************************************************************************/
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/*                           GODOT ENGINE                                */
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/*************************************************************************/
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                 */
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/*************************************************************************/
#ifndef BODY_PAIR_2D_SW_H
#define BODY_PAIR_2D_SW_H

#include "body_2d_sw.h"
#include "constraint_2d_sw.h"

class BodyPair2DSW : public Constraint2DSW {

	enum {
		MAX_CONTACTS=2
	};
	union {
		struct {
			Body2DSW *A;
			Body2DSW *B;
		};

		Body2DSW *_arr[2];
	};

	int shape_A;
	int shape_B;

	Space2DSW *space;

	struct Contact {

		Vector2 position;
		Vector2 normal;
		Vector2 local_A, local_B;
		real_t acc_normal_impulse;	// accumulated normal impulse (Pn)
		real_t acc_tangent_impulse;	// accumulated tangent impulse (Pt)
		real_t acc_bias_impulse;	// accumulated normal impulse for position bias (Pnb)
		real_t mass_normal, mass_tangent;
		real_t bias;

		real_t depth;
		bool active;
		Vector2 rA,rB;
		bool reused;
	};

	Vector2 offset_B; //use local A coordinates to avoid numerical issues on collision detection

	Vector2 sep_axis;
	Contact contacts[MAX_CONTACTS];
	int contact_count;
	bool collided;
	int cc;


	bool _test_ccd(float p_step,Body2DSW *p_A, int p_shape_A,const Matrix32& p_xform_A,Body2DSW *p_B, int p_shape_B,const Matrix32& p_xform_B,bool p_swap_result=false);
	void _validate_contacts();
	static void _add_contact(const Vector2& p_point_A,const Vector2& p_point_B,void *p_self);
	_FORCE_INLINE_ void _contact_added_callback(const Vector2& p_point_A,const Vector2& p_point_B);

public:

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

	BodyPair2DSW(Body2DSW *p_A, int p_shape_A,Body2DSW *p_B, int p_shape_B);
	~BodyPair2DSW();

};

#endif // BODY_PAIR_2D_SW_H
