btKinematicCharacterController.h

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/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2008 Erwin Coumans  http://bulletphysics.com

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 KINEMATIC_CHARACTER_CONTROLLER_H
#define KINEMATIC_CHARACTER_CONTROLLER_H

#include "LinearMath/btVector3.h"

#include "btCharacterControllerInterface.h"

#include "BulletCollision/BroadphaseCollision/btCollisionAlgorithm.h"


class btCollisionShape;
class btRigidBody;
class btCollisionWorld;
class btCollisionDispatcher;
class btPairCachingGhostObject;

class btKinematicCharacterController : public btCharacterControllerInterface
{
protected:

    btScalar m_halfHeight;
    
    btPairCachingGhostObject* m_ghostObject;
    btConvexShape*  m_convexShape;//is also in m_ghostObject, but it needs to be convex, so we store it here to avoid upcast
    
    btScalar m_verticalVelocity;
    btScalar m_verticalOffset;
    btScalar m_fallSpeed;
    btScalar m_jumpSpeed;
    btScalar m_maxJumpHeight;
    btScalar m_maxSlopeRadians; // Slope angle that is set (used for returning the exact value)
    btScalar m_maxSlopeCosine;  // Cosine equivalent of m_maxSlopeRadians (calculated once when set, for optimization)
    btScalar m_gravity;

    btScalar m_turnAngle;
    
    btScalar m_stepHeight;

    btScalar    m_addedMargin;//@todo: remove this and fix the code

    btVector3   m_walkDirection;
    btVector3   m_normalizedDirection;

    //some internal variables
    btVector3 m_currentPosition;
    btScalar  m_currentStepOffset;
    btVector3 m_targetPosition;

    btManifoldArray m_manifoldArray;

    bool m_touchingContact;
    btVector3 m_touchingNormal;

    bool  m_wasOnGround;
    bool  m_wasJumping;
    bool    m_useGhostObjectSweepTest;
    bool    m_useWalkDirection;
    btScalar    m_velocityTimeInterval;
    int m_upAxis;

    static btVector3* getUpAxisDirections();

    btVector3 computeReflectionDirection (const btVector3& direction, const btVector3& normal);
    btVector3 parallelComponent (const btVector3& direction, const btVector3& normal);
    btVector3 perpindicularComponent (const btVector3& direction, const btVector3& normal);

    bool recoverFromPenetration ( btCollisionWorld* collisionWorld);
    void stepUp (btCollisionWorld* collisionWorld);
    void updateTargetPositionBasedOnCollision (const btVector3& hit_normal, btScalar tangentMag = btScalar(0.0), btScalar normalMag = btScalar(1.0));
    void stepForwardAndStrafe (btCollisionWorld* collisionWorld, const btVector3& walkMove);
    void stepDown (btCollisionWorld* collisionWorld, btScalar dt);
public:
    btKinematicCharacterController (btPairCachingGhostObject* ghostObject,btConvexShape* convexShape,btScalar stepHeight, int upAxis = 1);
    ~btKinematicCharacterController ();
    

    virtual void updateAction( btCollisionWorld* collisionWorld,btScalar deltaTime)
    {
        preStep ( collisionWorld);
        playerStep (collisionWorld, deltaTime);
    }
    
    void    debugDraw(btIDebugDraw* debugDrawer);

    void setUpAxis (int axis)
    {
        if (axis < 0)
            axis = 0;
        if (axis > 2)
            axis = 2;
        m_upAxis = axis;
    }

    virtual void    setWalkDirection(const btVector3& walkDirection);

    virtual void setVelocityForTimeInterval(const btVector3& velocity,
                btScalar timeInterval);

    void reset ();
    void warp (const btVector3& origin);

    void preStep (  btCollisionWorld* collisionWorld);
    void playerStep ( btCollisionWorld* collisionWorld, btScalar dt);

    void setFallSpeed (btScalar fallSpeed);
    void setJumpSpeed (btScalar jumpSpeed);
    void setMaxJumpHeight (btScalar maxJumpHeight);
    bool canJump () const;

    void jump ();

    void setGravity(btScalar gravity);
    btScalar getGravity() const;

    void setMaxSlope(btScalar slopeRadians);
    btScalar getMaxSlope() const;

    btPairCachingGhostObject* getGhostObject();
    void    setUseGhostSweepTest(bool useGhostObjectSweepTest)
    {
        m_useGhostObjectSweepTest = useGhostObjectSweepTest;
    }

    bool onGround () const;
};

#endif // KINEMATIC_CHARACTER_CONTROLLER_H