//
// Lol Engine
//
// Copyright: (c) 2010-2012 Sam Hocevar <sam@hocevar.net>
//            (c) 2009-2012 Benjamin Huet <huet.benjamin@gmail.com>
//   This program is free software; you can redistribute it and/or
//   modify it under the terms of the Do What The Fuck You Want To
//   Public License, Version 2, as published by Sam Hocevar. See
//   http://sam.zoy.org/projects/COPYING.WTFPL for more details.
//

//
// The EasyPhysic class
// ------------------
//

#if !defined __EASYCONSTRAINT_EASYCONSTRAINT_H__
#define __EASYCONSTRAINT_EASYCONSTRAINT_H__

#ifdef HAVE_PHYS_USE_BULLET
#include "core.h"
#include "EasyPhysics.h"
#endif

namespace lol
{

namespace phys
{

class EasyConstraint
{

	friend class Simulation;
	friend class EasyPhysic;

#ifdef HAVE_PHYS_USE_BULLET

public:
	EasyConstraint() :
		m_typed_constraint(NULL),
		m_p2p_constraint(NULL),
		m_hinge_constraint(NULL),
		m_slider_constraint(NULL),
		m_cone_twist_constraint(NULL),
		m_6dof_constraint(NULL),
		m_owner_simulation(NULL),
		m_a_physobj(NULL),
		m_b_physobj(NULL),
		m_a_transform(lol::mat4(1.f)),
		m_b_transform(lol::mat4(1.f)),
		m_using_ref_a(false),
		m_disable_a2b_collision(false)

	{
	}
	~EasyConstraint()
	{
		delete m_typed_constraint;
		m_p2p_constraint = NULL;
		m_hinge_constraint = NULL;
		m_slider_constraint = NULL;
		m_cone_twist_constraint = NULL;
		m_6dof_constraint = NULL;
	}

	void AddToSimulation(class Simulation* current_simulation);
	void RemoveFromSimulation(class Simulation* current_simulation);

private:

	//check if Init can be done
	bool CanProceedWithInit()
	{
		if (!m_a_physobj || !m_b_physobj)
			return false;

		if (!m_a_physobj->m_rigid_body || !m_b_physobj->m_rigid_body)
			return false;

		return true;
	}

	//-------------------------------------------------------------------------
	//Init constraint functions
	//--
	void CustomInitConstraintToPoint2Point()
	{
		m_p2p_constraint = new btPoint2PointConstraint(*m_a_physobj->m_rigid_body, *m_b_physobj->m_rigid_body,
														LOL2BT_VEC3(m_a_transform.v3.xyz * LOL2BT_UNIT), LOL2BT_VEC3(m_b_transform.v3.xyz * LOL2BT_UNIT));
		m_typed_constraint = m_p2p_constraint;
	}

	void CustomInitConstraintToHinge()
	{
		m_hinge_constraint = new btHingeConstraint(*m_a_physobj->m_rigid_body, *m_b_physobj->m_rigid_body,
														btTransform(LOL2BT_QUAT(quat(m_a_transform)), LOL2BT_VEC3(m_a_transform.v3.xyz * LOL2BT_UNIT)),
														btTransform(LOL2BT_QUAT(quat(m_b_transform)), LOL2BT_VEC3(m_b_transform.v3.xyz * LOL2BT_UNIT)),
														m_using_ref_a);
		m_typed_constraint = m_hinge_constraint;
	}

	void CustomInitConstraintToSlider()
	{
		m_slider_constraint = new btSliderConstraint(*m_a_physobj->m_rigid_body, *m_b_physobj->m_rigid_body,
														btTransform(LOL2BT_QUAT(quat(m_a_transform)), LOL2BT_VEC3(m_a_transform.v3.xyz * LOL2BT_UNIT)),
														btTransform(LOL2BT_QUAT(quat(m_b_transform)), LOL2BT_VEC3(m_b_transform.v3.xyz * LOL2BT_UNIT)),
														m_using_ref_a);
		m_typed_constraint = m_slider_constraint;
	}

	void CustomInitConstraintToConeTwist()
	{
		m_cone_twist_constraint = new btConeTwistConstraint(*m_a_physobj->m_rigid_body, *m_b_physobj->m_rigid_body,
														btTransform(LOL2BT_QUAT(quat(m_a_transform)), LOL2BT_VEC3(m_a_transform.v3.xyz * LOL2BT_UNIT)),
														btTransform(LOL2BT_QUAT(quat(m_b_transform)), LOL2BT_VEC3(m_b_transform.v3.xyz * LOL2BT_UNIT)));
		m_typed_constraint = m_cone_twist_constraint;
	}

	void CustomInitConstraintTo6Dof()
	{
		m_6dof_constraint = new btGeneric6DofConstraint(*m_a_physobj->m_rigid_body, *m_b_physobj->m_rigid_body,
														btTransform(LOL2BT_QUAT(quat(m_a_transform)), LOL2BT_VEC3(m_a_transform.v3.xyz * LOL2BT_UNIT)),
														btTransform(LOL2BT_QUAT(quat(m_b_transform)), LOL2BT_VEC3(m_b_transform.v3.xyz * LOL2BT_UNIT)),
														m_using_ref_a);
		m_typed_constraint = m_6dof_constraint;
	}

	btTypedConstraint*			m_typed_constraint;
	btPoint2PointConstraint*	m_p2p_constraint;
	btHingeConstraint*			m_hinge_constraint;
	btSliderConstraint*			m_slider_constraint;
	btConeTwistConstraint*		m_cone_twist_constraint;
	btGeneric6DofConstraint*	m_6dof_constraint;

#else  // NO PHYSIC IMPLEMENTATION

public:
	EasyConstraint() :
		m_a_physobj(NULL),
		m_b_physobj(NULL),
		m_a_transform(lol::mat4(1.f)),
		m_b_transform(lol::mat4(1.f)),
		m_using_ref_a(false),
		m_disable_a2b_collision(false)
	{
	}

private:

	void AddToSimulation(class Simulation* current_simulation) { }
	void RemoveFromSimulation(class Simulation* current_simulation) { }

	//check if Init can be done
	bool CanProceedWithInit() { return false; }
	void CustomInitConstraintToPoint2Point() { }
	void CustomInitConstraintToHinge() { }
	void CustomInitConstraintToSlider() { }
	void CustomInitConstraintToConeTwist() { }
	void CustomInitConstraintTo6Dof() { }

#endif // PHYSIC IMPLEMENTATION

public:
	void InitConstraintToPoint2Point()	{ if (CanProceedWithInit()) CustomInitConstraintToPoint2Point(); }
	void InitConstraintToHinge()		{ if (CanProceedWithInit()) CustomInitConstraintToHinge(); }
	void InitConstraintToSlider()		{ if (CanProceedWithInit()) CustomInitConstraintToSlider(); }
	void InitConstraintToConeTwist()	{ if (CanProceedWithInit()) CustomInitConstraintToConeTwist(); }
	void InitConstraintTo6Dof()			{ if (CanProceedWithInit()) CustomInitConstraintTo6Dof(); }

	//Set given physic object to the proper slot.
	void SetPhysObjA(EasyPhysic* NewPhysObj, lol::mat4 NewTransform) { SetPhysObj(false, NewPhysObj, NewTransform); }
	void SetPhysObjB(EasyPhysic* NewPhysObj, lol::mat4 NewTransform) { SetPhysObj(true, NewPhysObj, NewTransform); }
	void SetPhysObj(bool SetToB, EasyPhysic* NewPhysObj, lol::mat4 NewTransform)
	{
		if (SetToB)
		{
			m_b_physobj = NewPhysObj;
			m_b_transform = NewTransform;
		}
		else
		{
			m_a_physobj = NewPhysObj;
			m_a_transform = NewTransform;
		}
	}

	//Set whether or not the physic engine should use the A object as the reference (most constraint transform are local).
	void SetRefAsA(bool NewUseRefA)
	{
		m_using_ref_a = NewUseRefA;
	}

	//Set whether or not to disable the collision between the bodies
	void DisableCollisionBetweenObjs(bool DisableCollision)
	{
		m_disable_a2b_collision = DisableCollision;
	}

private:
	Simulation*					m_owner_simulation;
	EasyPhysic*					m_a_physobj;
	EasyPhysic*					m_b_physobj;
	lol::mat4					m_a_transform;
	lol::mat4					m_b_transform;
	bool						m_using_ref_a;
	bool						m_disable_a2b_collision;

};

} /* namespace phys */

} /* namespace lol */

#endif /* __EASYCONSTRAINT_EASYCONSTRAINT_H__ */