CarEngine.h

//
// CarEngine.h
// header file for CarEngine.cpp
//
// Copyright (c) 2001-2011 Virtual Terrain Project
// Free for all uses, see license.txt for details.
//

#ifndef CARENGINEH
#define CARENGINEH

#include "vtdata/HeightField.h"
#include "Vehicles.h"

enum CarEngineMode { NONE, JUST_DRIVE, FOLLOW_ROAD, FOLLOW_PATH };

class CarEngine : public vtEngine
{
public:
    CarEngine(Vehicle *vehicle, vtHeightField3d *hf);

    bool Valid();
    void Eval();
    void IgnoreElapsedTime();

    FPoint3 GetCurPos() { return m_vCurPos; }
    void SetEarthPos(const DPoint2 &pos);
    DPoint2 GetEarthPos();

    void SetSpeed(float fMeterPerSec);

    void SetRotation(float fRot);
    float GetRotation() { return m_fCurRotation; }

    void SetSteeringAngle(float fRadians) { m_fSteeringAngle = fRadians; }
    void SetFriction(float factor) { m_fFriction = factor; }

    void SetCameraFollow(bool bOn) { m_bCameraFollow = bOn; }
    void SetCameraDistance(float fMeters) { m_bCameraDistance = fMeters; }

protected:
    void ApplyCurrentLocation(bool bAlignOnGround);

    float SetPitch();  //returns new height for car.

    //move car to the given vector
    //change rotation about Y axis based on current and next position.
    //height is average of tire points
    void MoveCarTo(const FPoint3 &pos);

    //spin all wheels for distance traveled.
    void SpinWheels(float radians);

    vtHeightField3d *m_pHeightField;

    //what mode the engine is operating at.
    CarEngineMode m_eMode;

    FPoint3 m_vCurPos;      // current position
    float m_fCurRotation;   // rotation around Y axis(Yaw)
    float m_fCurPitch;      // rotation around orientation axis (Pitch)
    FPoint3 m_vAxis;        // orientation axis, determined by where wheels are w/respect to ground

    float m_fSpeed;         // speed in meters per second
    float m_fTargetSpeed;   // target speed
    float m_fPrevTime;      // last time that eval was run on.

    //tires
    vtTransform *FrontLeft() { return m_pVehicle->m_pFrontLeft; }
    vtTransform *FrontRight() { return m_pVehicle->m_pFrontRight; }
    vtTransform *RearLeft() { return m_pVehicle->m_pRearLeft; }
    vtTransform *RearRight() { return m_pVehicle->m_pRearRight; }

    float m_fSteeringAngle;
    float m_fFriction;

    //a setup flag - first eval doesn't run right...
    bool m_bFirstTime;

    bool m_bCameraFollow;
    float m_bCameraDistance;

    Vehicle *m_pVehicle;
};
typedef osg::ref_ptr<CarEngine> CarEnginePtr;


#endif // CARENGINEH