SNMPhysicsUpdateVelocity.h

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/*********************************************************\
 *  File: SNMPhysicsUpdateVelocity.h                     *
 *
 *  Copyright (C) 2002-2012 The PixelLight Team (http://www.pixellight.org/)
 *
 *  This file is part of PixelLight.
 *
 *  PixelLight is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  PixelLight is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with PixelLight. If not, see <http://www.gnu.org/licenses/>.
\*********************************************************/


#ifndef __PLPHYSICS_SCENENODEMODIFIERS_UPDATEVELOCITY_H__
#define __PLPHYSICS_SCENENODEMODIFIERS_UPDATEVELOCITY_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include <PLCore/Base/Event/EventHandler.h>
#include <PLMath/Vector3.h>
#include <PLMath/Quaternion.h>
#include "PLPhysics/SceneNodeModifiers/SNMPhysics.h"


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLPhysics {


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Updates the linear and angular velocity of physics bodies according to the scene node movement
*
*  @remarks
*    If there's a static (immobile) physics body which should for example move along a well defined path, this
*    static physics body will not interact properly with dynamic physics bodies because it's assumed to stay on one
*    and the same place. But when you have a moving platform or an escalator, this physics body should still be
*    static and therefore not influenced by other physics bodies, but other dynamic physics object should interact
*    correctly with the static moving physics body. (for example move with the platform) The static physics body is
*    in such a case called a kinematic physics body and can be realized within the scene graph by adding this scene
*    node modifier to your scene node which should be a kinematic physics body.
*
*  @note
*    - Keeps track of position changes and updates the linear velocity of the static physics bodies
*    - Keeps track of rotation changes and updates the angular velocity of the static physics bodies
*    - Scene container ownership changes are not tracked
*/
class SNMPhysicsUpdateVelocity : public SNMPhysics {


    //[-------------------------------------------------------]
    //[ RTTI interface                                        ]
    //[-------------------------------------------------------]
    pl_class(PLPHYSICS_RTTI_EXPORT, SNMPhysicsUpdateVelocity, "PLPhysics", PLPhysics::SNMPhysics, "Updates the linear and angular velocity of physics bodies according to the scene node movement")
        // Constructors
        pl_constructor_1(ParameterConstructor,  PLScene::SceneNode&,    "Parameter constructor",    "")
    pl_class_end


    //[-------------------------------------------------------]
    //[ Public functions                                      ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] cSceneNode
        *    Owner scene node
        */
        PLPHYSICS_API SNMPhysicsUpdateVelocity(PLScene::SceneNode &cSceneNode);

        /**
        *  @brief
        *    Destructor
        */
        PLPHYSICS_API virtual ~SNMPhysicsUpdateVelocity();


    //[-------------------------------------------------------]
    //[ Protected virtual PLScene::SceneNodeModifier functions ]
    //[-------------------------------------------------------]
    protected:
        PLPHYSICS_API virtual void OnActivate(bool bActivate) override;


    //[-------------------------------------------------------]
    //[ Private functions                                     ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    Called when the scene node position changed
        */
        void OnPosition();

        /**
        *  @brief
        *    Called when the scene node rotation changed
        */
        void OnRotation();


    //[-------------------------------------------------------]
    //[ Private event handlers                                ]
    //[-------------------------------------------------------]
    private:
        PLCore::EventHandler<> EventHandlerPosition;
        PLCore::EventHandler<> EventHandlerRotation;


    //[-------------------------------------------------------]
    //[ Private data                                          ]
    //[-------------------------------------------------------]
    private:
        bool               m_bPreviousPosition; /**< Is there a previous scene node position? */
        PLMath::Vector3    m_vPreviousPosition; /**< Previous scene node position */
        bool               m_bPreviousRotation; /**< Is there a previous scene node rotation? */
        PLMath::Quaternion m_qPreviousRotation; /**< Previous scene node rotation */


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLPhysics


#endif // __PLPHYSICS_SCENENODEMODIFIERS_UPDATEVELOCITY_H__