dali-physics/third-party/bullet3/src/BulletDynamics/Vehicle/btWheelInfo.cpp

   1 /*
   2  * Copyright (c) 2005 Erwin Coumans https://bulletphysics.org
   3  *
   4  * Permission to use, copy, modify, distribute and sell this software
   5  * and its documentation for any purpose is hereby granted without fee,
   6  * provided that the above copyright notice appear in all copies.
   7  * Erwin Coumans makes no representations about the suitability
   8  * of this software for any purpose.
   9  * It is provided "as is" without express or implied warranty.
  10 */
  11 #include "btWheelInfo.h"
  12 #include "BulletDynamics/Dynamics/btRigidBody.h"  // for pointvelocity
  13
  14 btScalar btWheelInfo::getSuspensionRestLength() const
  15 {
  16         return m_suspensionRestLength1;
  17 }
  18
  19 void btWheelInfo::updateWheel(const btRigidBody& chassis, RaycastInfo& raycastInfo)
  20 {
  21         (void)raycastInfo;
  22
  23         if (m_raycastInfo.m_isInContact)
  24
  25         {
  26                 btScalar project = m_raycastInfo.m_contactNormalWS.dot(m_raycastInfo.m_wheelDirectionWS);
  27                 btVector3 chassis_velocity_at_contactPoint;
  28                 btVector3 relpos = m_raycastInfo.m_contactPointWS - chassis.getCenterOfMassPosition();
  29                 chassis_velocity_at_contactPoint = chassis.getVelocityInLocalPoint(relpos);
  30                 btScalar projVel = m_raycastInfo.m_contactNormalWS.dot(chassis_velocity_at_contactPoint);
  31                 if (project >= btScalar(-0.1))
  32                 {
  33                         m_suspensionRelativeVelocity = btScalar(0.0);
  34                         m_clippedInvContactDotSuspension = btScalar(1.0) / btScalar(0.1);
  35                 }
  36                 else
  37                 {
  38                         btScalar inv = btScalar(-1.) / project;
  39                         m_suspensionRelativeVelocity = projVel * inv;
  40                         m_clippedInvContactDotSuspension = inv;
  41                 }
  42         }
  43
  44         else  // Not in contact : position wheel in a nice (rest length) position
  45         {
  46                 m_raycastInfo.m_suspensionLength = this->getSuspensionRestLength();
  47                 m_suspensionRelativeVelocity = btScalar(0.0);
  48                 m_raycastInfo.m_contactNormalWS = -m_raycastInfo.m_wheelDirectionWS;
  49                 m_clippedInvContactDotSuspension = btScalar(1.0);
  50         }
  51 }