godot/thirdparty/bullet/BulletCollision/NarrowPhaseCollision/btManifoldPoint.h

/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, 
including commercial applications, and to alter it and redistribute it freely, 
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/

#ifndef BT_MANIFOLD_CONTACT_POINT_H
#define BT_MANIFOLD_CONTACT_POINT_H

#include "LinearMath/btVector3.h"
#include "LinearMath/btTransformUtil.h"

#ifdef PFX_USE_FREE_VECTORMATH
	#include "physics_effects/base_level/solver/pfx_constraint_row.h"
typedef sce::PhysicsEffects::PfxConstraintRow btConstraintRow;
#else
	// Don't change following order of parameters
	ATTRIBUTE_ALIGNED16(struct) btConstraintRow {
		btScalar m_normal[3];
		btScalar m_rhs;
		btScalar m_jacDiagInv;
		btScalar m_lowerLimit;
		btScalar m_upperLimit;
		btScalar m_accumImpulse;
	};
	typedef btConstraintRow PfxConstraintRow;
#endif //PFX_USE_FREE_VECTORMATH

enum btContactPointFlags
{
	BT_CONTACT_FLAG_LATERAL_FRICTION_INITIALIZED=1,
	BT_CONTACT_FLAG_HAS_CONTACT_CFM=2,
	BT_CONTACT_FLAG_HAS_CONTACT_ERP=4,
    BT_CONTACT_FLAG_CONTACT_STIFFNESS_DAMPING = 8,
	BT_CONTACT_FLAG_FRICTION_ANCHOR = 16,
};

/// ManifoldContactPoint collects and maintains persistent contactpoints.
/// used to improve stability and performance of rigidbody dynamics response.
class btManifoldPoint
	{
		public:
			btManifoldPoint()
				:m_userPersistentData(0),
				m_contactPointFlags(0),
				m_appliedImpulse(0.f),
                m_appliedImpulseLateral1(0.f),
				m_appliedImpulseLateral2(0.f),
				m_contactMotion1(0.f),
				m_contactMotion2(0.f),
				m_contactCFM(0.f),
				m_contactERP(0.f),
				m_frictionCFM(0.f),
				m_lifeTime(0)
			{
			}

			btManifoldPoint( const btVector3 &pointA, const btVector3 &pointB, 
					const btVector3 &normal, 
					btScalar distance ) :
					m_localPointA( pointA ), 
					m_localPointB( pointB ), 
					m_normalWorldOnB( normal ), 
					m_distance1( distance ),
					m_combinedFriction(btScalar(0.)),
					m_combinedRollingFriction(btScalar(0.)),
                    m_combinedSpinningFriction(btScalar(0.)),
                    m_combinedRestitution(btScalar(0.)),
					m_userPersistentData(0),
					m_contactPointFlags(0),
					m_appliedImpulse(0.f),
                    m_appliedImpulseLateral1(0.f),
					m_appliedImpulseLateral2(0.f),
					m_contactMotion1(0.f),
					m_contactMotion2(0.f),
					m_contactCFM(0.f),
					m_contactERP(0.f),
					m_frictionCFM(0.f),
					m_lifeTime(0)
			{
				
			}

			

			btVector3 m_localPointA;			
			btVector3 m_localPointB;			
			btVector3	m_positionWorldOnB;
			///m_positionWorldOnA is redundant information, see getPositionWorldOnA(), but for clarity
			btVector3	m_positionWorldOnA;
			btVector3 m_normalWorldOnB;
		
			btScalar	m_distance1;
			btScalar	m_combinedFriction;
			btScalar	m_combinedRollingFriction;//torsional friction orthogonal to contact normal, useful to make spheres stop rolling forever
            btScalar	m_combinedSpinningFriction;//torsional friction around contact normal, useful for grasping objects
            btScalar	m_combinedRestitution;

			//BP mod, store contact triangles.
			int			m_partId0;
			int			m_partId1;
			int			m_index0;
			int			m_index1;
				
			mutable void*	m_userPersistentData;
			//bool			m_lateralFrictionInitialized;
			int				m_contactPointFlags;
			
			btScalar		m_appliedImpulse;
			btScalar		m_appliedImpulseLateral1;
			btScalar		m_appliedImpulseLateral2;
			btScalar		m_contactMotion1;
			btScalar		m_contactMotion2;
			
			union
			{
                btScalar		m_contactCFM;
                btScalar        m_combinedContactStiffness1;
			};
			
			union
			{
                btScalar		m_contactERP;
                btScalar        m_combinedContactDamping1;
			};

			btScalar		m_frictionCFM;

			int				m_lifeTime;//lifetime of the contactpoint in frames
			
			btVector3		m_lateralFrictionDir1;
			btVector3		m_lateralFrictionDir2;




			btScalar getDistance() const
			{
				return m_distance1;
			}
			int	getLifeTime() const
			{
				return m_lifeTime;
			}

			const btVector3& getPositionWorldOnA() const {
				return m_positionWorldOnA;
//				return m_positionWorldOnB + m_normalWorldOnB * m_distance1;
			}

			const btVector3& getPositionWorldOnB() const
			{
				return m_positionWorldOnB;
			}

			void	setDistance(btScalar dist)
			{
				m_distance1 = dist;
			}
			
			///this returns the most recent applied impulse, to satisfy contact constraints by the constraint solver
			btScalar	getAppliedImpulse() const
			{
				return m_appliedImpulse;
			}

			

	};

#endif //BT_MANIFOLD_CONTACT_POINT_H