gremlin/libs/bullet/BulletDynamics/Vehicle/btWheelInfo.cpp

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2011-01-18 20:02:48 +00:00
/*
* Copyright (c) 2005 Erwin Coumans http://continuousphysics.com/Bullet/
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies.
* Erwin Coumans makes no representations about the suitability
* of this software for any purpose.
* It is provided "as is" without express or implied warranty.
*/
#include "btWheelInfo.h"
#include "BulletDynamics/Dynamics/btRigidBody.h" // for pointvelocity
btScalar btWheelInfo::getSuspensionRestLength() const
{
return m_suspensionRestLength1;
}
void btWheelInfo::updateWheel(const btRigidBody& chassis,RaycastInfo& raycastInfo)
{
(void)raycastInfo;
if (m_raycastInfo.m_isInContact)
{
btScalar project= m_raycastInfo.m_contactNormalWS.dot( m_raycastInfo.m_wheelDirectionWS );
btVector3 chassis_velocity_at_contactPoint;
btVector3 relpos = m_raycastInfo.m_contactPointWS - chassis.getCenterOfMassPosition();
chassis_velocity_at_contactPoint = chassis.getVelocityInLocalPoint( relpos );
btScalar projVel = m_raycastInfo.m_contactNormalWS.dot( chassis_velocity_at_contactPoint );
if ( project >= btScalar(-0.1))
{
m_suspensionRelativeVelocity = btScalar(0.0);
m_clippedInvContactDotSuspension = btScalar(1.0) / btScalar(0.1);
}
else
{
btScalar inv = btScalar(-1.) / project;
m_suspensionRelativeVelocity = projVel * inv;
m_clippedInvContactDotSuspension = inv;
}
}
else // Not in contact : position wheel in a nice (rest length) position
{
m_raycastInfo.m_suspensionLength = this->getSuspensionRestLength();
m_suspensionRelativeVelocity = btScalar(0.0);
m_raycastInfo.m_contactNormalWS = -m_raycastInfo.m_wheelDirectionWS;
m_clippedInvContactDotSuspension = btScalar(1.0);
}
}