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 "BulletDynamics/Dynamics/btRigidBody.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_ALIGNED64 (struct)    btSolverBodyObsolete
{
    BT_DECLARE_ALIGNED_ALLOCATOR();
    btVector3       m_deltaLinearVelocity;
    btVector3       m_deltaAngularVelocity;
    btVector3       m_angularFactor;
    btVector3       m_invMass;
    btRigidBody*    m_originalBody;
    btVector3       m_pushVelocity;
    btVector3       m_turnVelocity;

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

    SIMD_FORCE_INLINE void  getAngularVelocity(btVector3& angVel) const
    {
        if (m_originalBody)
            angVel = m_originalBody->getAngularVelocity()+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_invMass)
        {
            m_deltaLinearVelocity += linearComponent*impulseMagnitude;
            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_turnVelocity += angularComponent*(impulseMagnitude*m_angularFactor);
        }
    }
    
    void    writebackVelocity()
    {
        if (m_originalBody)
        {
            m_originalBody->setLinearVelocity(m_originalBody->getLinearVelocity()+ m_deltaLinearVelocity);
            m_originalBody->setAngularVelocity(m_originalBody->getAngularVelocity()+m_deltaAngularVelocity);
            
            //m_originalBody->setCompanionId(-1);
        }
    }


    void    writebackVelocity(btScalar timeStep)
    {
        (void) timeStep;
        if (m_originalBody)
        {
            m_originalBody->setLinearVelocity(m_originalBody->getLinearVelocity()+ m_deltaLinearVelocity);
            m_originalBody->setAngularVelocity(m_originalBody->getAngularVelocity()+m_deltaAngularVelocity);
            
            //correct the position/orientation based on push/turn recovery
            btTransform newTransform;
            btTransformUtil::integrateTransform(m_originalBody->getWorldTransform(),m_pushVelocity,m_turnVelocity,timeStep,newTransform);
            m_originalBody->setWorldTransform(newTransform);
            
            //m_originalBody->setCompanionId(-1);
        }
    }
    


};

#endif //BT_SOLVER_BODY_H