btWheelInfo.h

Go to the documentation of this file.

/*
 * 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.
*/
#ifndef WHEEL_INFO_H
#define WHEEL_INFO_H

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

class btRigidBody;

struct btWheelInfoConstructionInfo
{
    btVector3   m_chassisConnectionCS;
    btVector3   m_wheelDirectionCS;
    btVector3   m_wheelAxleCS;
    btScalar    m_suspensionRestLength;
    btScalar    m_maxSuspensionTravelCm;
    btScalar    m_wheelRadius;
    
    btScalar        m_suspensionStiffness;
    btScalar        m_wheelsDampingCompression;
    btScalar        m_wheelsDampingRelaxation;
    btScalar        m_frictionSlip;
    btScalar        m_maxSuspensionForce;
    bool m_bIsFrontWheel;
    
};

struct btWheelInfo
{
    struct RaycastInfo
    {
        //set by raycaster
        btVector3   m_contactNormalWS;//contactnormal
        btVector3   m_contactPointWS;//raycast hitpoint
        btScalar    m_suspensionLength;
        btVector3   m_hardPointWS;//raycast starting point
        btVector3   m_wheelDirectionWS; //direction in worldspace
        btVector3   m_wheelAxleWS; // axle in worldspace
        bool        m_isInContact;
        void*       m_groundObject; //could be general void* ptr
    };

    RaycastInfo m_raycastInfo;

    btTransform m_worldTransform;
    
    btVector3   m_chassisConnectionPointCS; //const
    btVector3   m_wheelDirectionCS;//const
    btVector3   m_wheelAxleCS; // const or modified by steering
    btScalar    m_suspensionRestLength1;//const
    btScalar    m_maxSuspensionTravelCm;
    btScalar getSuspensionRestLength() const;
    btScalar    m_wheelsRadius;//const
    btScalar    m_suspensionStiffness;//const
    btScalar    m_wheelsDampingCompression;//const
    btScalar    m_wheelsDampingRelaxation;//const
    btScalar    m_frictionSlip;
    btScalar    m_steering;
    btScalar    m_rotation;
    btScalar    m_deltaRotation;
    btScalar    m_rollInfluence;
    btScalar    m_maxSuspensionForce;

    btScalar    m_engineForce;

    btScalar    m_brake;
    
    bool m_bIsFrontWheel;
    
    void*       m_clientInfo;//can be used to store pointer to sync transforms...

    btWheelInfo(btWheelInfoConstructionInfo& ci)

    {

        m_suspensionRestLength1 = ci.m_suspensionRestLength;
        m_maxSuspensionTravelCm = ci.m_maxSuspensionTravelCm;

        m_wheelsRadius = ci.m_wheelRadius;
        m_suspensionStiffness = ci.m_suspensionStiffness;
        m_wheelsDampingCompression = ci.m_wheelsDampingCompression;
        m_wheelsDampingRelaxation = ci.m_wheelsDampingRelaxation;
        m_chassisConnectionPointCS = ci.m_chassisConnectionCS;
        m_wheelDirectionCS = ci.m_wheelDirectionCS;
        m_wheelAxleCS = ci.m_wheelAxleCS;
        m_frictionSlip = ci.m_frictionSlip;
        m_steering = btScalar(0.);
        m_engineForce = btScalar(0.);
        m_rotation = btScalar(0.);
        m_deltaRotation = btScalar(0.);
        m_brake = btScalar(0.);
        m_rollInfluence = btScalar(0.1);
        m_bIsFrontWheel = ci.m_bIsFrontWheel;
        m_maxSuspensionForce = ci.m_maxSuspensionForce;

    }

    void    updateWheel(const btRigidBody& chassis,RaycastInfo& raycastInfo);

    btScalar    m_clippedInvContactDotSuspension;
    btScalar    m_suspensionRelativeVelocity;
    //calculated by suspension
    btScalar    m_wheelsSuspensionForce;
    btScalar    m_skidInfo;

};

#endif //WHEEL_INFO_H