btSolverBody.h

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/*
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_SOLVER_BODY_H
#define BT_SOLVER_BODY_H

class   btRigidBody;
#include "LinearMath/btVector3.h"
#include "LinearMath/btMatrix3x3.h"

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

#ifdef BT_USE_SSE
#define USE_SIMD 1
#endif //


#ifdef USE_SIMD

struct  btSimdScalar
{
        SIMD_FORCE_INLINE       btSimdScalar()
        {

        }

        SIMD_FORCE_INLINE       btSimdScalar(float      fl)
        :m_vec128 (_mm_set1_ps(fl))
        {
        }

        SIMD_FORCE_INLINE       btSimdScalar(__m128 v128)
                :m_vec128(v128)
        {
        }
        union
        {
                __m128          m_vec128;
                float           m_floats[4];
                int                     m_ints[4];
                btScalar        m_unusedPadding;
        };
        SIMD_FORCE_INLINE       __m128  get128()
        {
                return m_vec128;
        }

        SIMD_FORCE_INLINE       const __m128    get128() const
        {
                return m_vec128;
        }

        SIMD_FORCE_INLINE       void    set128(__m128 v128)
        {
                m_vec128 = v128;
        }

        SIMD_FORCE_INLINE       operator       __m128()       
        { 
                return m_vec128; 
        }
        SIMD_FORCE_INLINE       operator const __m128() const 
        { 
                return m_vec128; 
        }
        
        SIMD_FORCE_INLINE       operator float() const 
        { 
                return m_floats[0]; 
        }

};

SIMD_FORCE_INLINE btSimdScalar 
operator*(const btSimdScalar& v1, const btSimdScalar& v2) 
{
        return btSimdScalar(_mm_mul_ps(v1.get128(),v2.get128()));
}

SIMD_FORCE_INLINE btSimdScalar 
operator+(const btSimdScalar& v1, const btSimdScalar& v2) 
{
        return btSimdScalar(_mm_add_ps(v1.get128(),v2.get128()));
}


#else
#define btSimdScalar btScalar
#endif

ATTRIBUTE_ALIGNED16 (struct)    btSolverBody
{
        BT_DECLARE_ALIGNED_ALLOCATOR();
        btTransform             m_worldTransform;
        btVector3               m_deltaLinearVelocity;
        btVector3               m_deltaAngularVelocity;
        btVector3               m_angularFactor;
        btVector3               m_linearFactor;
        btVector3               m_invMass;
        btVector3               m_pushVelocity;
        btVector3               m_turnVelocity;
        btVector3               m_linearVelocity;
        btVector3               m_angularVelocity;
        btVector3               m_externalForceImpulse;
        btVector3               m_externalTorqueImpulse;

        btRigidBody*    m_originalBody;
        void    setWorldTransform(const btTransform& worldTransform)
        {
                m_worldTransform = worldTransform;
        }

        const btTransform& getWorldTransform() const
        {
                return m_worldTransform;
        }
        
        

        SIMD_FORCE_INLINE void  getVelocityInLocalPointNoDelta(const btVector3& rel_pos, btVector3& velocity ) const
        {
                if (m_originalBody)
                        velocity = m_linearVelocity + m_externalForceImpulse + (m_angularVelocity+m_externalTorqueImpulse).cross(rel_pos);
                else
                        velocity.setValue(0,0,0);
        }


        SIMD_FORCE_INLINE void  getVelocityInLocalPointObsolete(const btVector3& rel_pos, btVector3& velocity ) const
        {
                if (m_originalBody)
                        velocity = m_linearVelocity+m_deltaLinearVelocity + (m_angularVelocity+m_deltaAngularVelocity).cross(rel_pos);
                else
                        velocity.setValue(0,0,0);
        }

        SIMD_FORCE_INLINE void  getAngularVelocity(btVector3& angVel) const
        {
                if (m_originalBody)
                        angVel =m_angularVelocity+m_deltaAngularVelocity;
                else
                        angVel.setValue(0,0,0);
        }


        //Optimization for the iterative solver: avoid calculating constant terms involving inertia, normal, relative position
        SIMD_FORCE_INLINE void applyImpulse(const btVector3& linearComponent, const btVector3& angularComponent,const btScalar impulseMagnitude)
        {
                if (m_originalBody)
                {
                        m_deltaLinearVelocity += linearComponent*impulseMagnitude*m_linearFactor;
                        m_deltaAngularVelocity += angularComponent*(impulseMagnitude*m_angularFactor);
                }
        }

        SIMD_FORCE_INLINE void internalApplyPushImpulse(const btVector3& linearComponent, const btVector3& angularComponent,btScalar impulseMagnitude)
        {
                if (m_originalBody)
                {
                        m_pushVelocity += linearComponent*impulseMagnitude*m_linearFactor;
                        m_turnVelocity += angularComponent*(impulseMagnitude*m_angularFactor);
                }
        }



        const btVector3& getDeltaLinearVelocity() const
        {
                return m_deltaLinearVelocity;
        }

        const btVector3& getDeltaAngularVelocity() const
        {
                return m_deltaAngularVelocity;
        }

        const btVector3& getPushVelocity() const 
        {
                return m_pushVelocity;
        }

        const btVector3& getTurnVelocity() const 
        {
                return m_turnVelocity;
        }


                
        btVector3& internalGetDeltaLinearVelocity()
        {
                return m_deltaLinearVelocity;
        }

        btVector3& internalGetDeltaAngularVelocity()
        {
                return m_deltaAngularVelocity;
        }

        const btVector3& internalGetAngularFactor() const
        {
                return m_angularFactor;
        }

        const btVector3& internalGetInvMass() const
        {
                return m_invMass;
        }

        void internalSetInvMass(const btVector3& invMass)
        {
                m_invMass = invMass;
        }
        
        btVector3& internalGetPushVelocity()
        {
                return m_pushVelocity;
        }

        btVector3& internalGetTurnVelocity()
        {
                return m_turnVelocity;
        }

        SIMD_FORCE_INLINE void  internalGetVelocityInLocalPointObsolete(const btVector3& rel_pos, btVector3& velocity ) const
        {
                velocity = m_linearVelocity+m_deltaLinearVelocity + (m_angularVelocity+m_deltaAngularVelocity).cross(rel_pos);
        }

        SIMD_FORCE_INLINE void  internalGetAngularVelocity(btVector3& angVel) const
        {
                angVel = m_angularVelocity+m_deltaAngularVelocity;
        }


        //Optimization for the iterative solver: avoid calculating constant terms involving inertia, normal, relative position
        SIMD_FORCE_INLINE void internalApplyImpulse(const btVector3& linearComponent, const btVector3& angularComponent,const btScalar impulseMagnitude)
        {
                if (m_originalBody)
                {
                        m_deltaLinearVelocity += linearComponent*impulseMagnitude*m_linearFactor;
                        m_deltaAngularVelocity += angularComponent*(impulseMagnitude*m_angularFactor);
                }
        }
                
        
        

        void    writebackVelocity()
        {
                if (m_originalBody)
                {
                        m_linearVelocity +=m_deltaLinearVelocity;
                        m_angularVelocity += m_deltaAngularVelocity;
                        
                        //m_originalBody->setCompanionId(-1);
                }
        }


        void    writebackVelocityAndTransform(btScalar timeStep, btScalar splitImpulseTurnErp)
        {
        (void) timeStep;
                if (m_originalBody)
                {
                        m_linearVelocity += m_deltaLinearVelocity;
                        m_angularVelocity += m_deltaAngularVelocity;
                        
                        //correct the position/orientation based on push/turn recovery
                        btTransform newTransform;
                        if (m_pushVelocity[0]!=0.f || m_pushVelocity[1]!=0 || m_pushVelocity[2]!=0 || m_turnVelocity[0]!=0.f || m_turnVelocity[1]!=0 || m_turnVelocity[2]!=0)
                        {
                        //      btQuaternion orn = m_worldTransform.getRotation();
                                btTransformUtil::integrateTransform(m_worldTransform,m_pushVelocity,m_turnVelocity*splitImpulseTurnErp,timeStep,newTransform);
                                m_worldTransform = newTransform;
                        }
                        //m_worldTransform.setRotation(orn);
                        //m_originalBody->setCompanionId(-1);
                }
        }
        


};

#endif //BT_SOLVER_BODY_H