MousePicking.h

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/*********************************************************\
 *  File: MousePicking.h                                 *
 *
 *  Copyright (C) 2002-2011 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 __PLENGINE_MOUSEPICKING_H__
#define __PLENGINE_MOUSEPICKING_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include "PLEngine/Picking/Picking.h"


//[-------------------------------------------------------]
//[ Forward declarations                                  ]
//[-------------------------------------------------------]
namespace PLCore {
    class Frontend;
}
namespace PLMath {
    class Vector2i;
}
namespace PLScene {
    class SNCamera;
}


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLEngine {


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Class offering scene picking functionality by using the mouse
*/
class MousePicking : public Picking {


    //[-------------------------------------------------------]
    //[ Public functions                                      ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] cFrontend
        *    Frontend instance used to determine the mouse position
        *  @param[in] pCamera
        *    Camera to perform the picking with, if a null pointer no picking is possible
        */
        PL_API MousePicking(PLCore::Frontend &cFrontend, PLScene::SNCamera *pCamera = nullptr);

        /**
        *  @brief
        *    Destructor
        */
        PL_API virtual ~MousePicking();

        /**
        *  @brief
        *    Returns the frontend instance used to determine the mouse position
        *
        *  @return
        *    The frontend instance used to determine the mouse position
        */
        PL_API PLCore::Frontend &GetFrontend() const;

        /**
        *  @brief
        *    Returns the camera to perform the picking with
        *
        *  @return
        *    The camera to perform the picking with, if a null pointer no picking is possible
        */
        PL_API PLScene::SNCamera *GetCamera() const;

        /**
        *  @brief
        *    Sets the camera to perform the picking with
        *
        *  @param[in] pCamera
        *    The camera to perform the picking with, if a null pointer no picking is possible
        */
        PL_API void SetCamera(PLScene::SNCamera *pCamera);

        /**
        *  @brief
        *    Performs picking by using the current camera and current mouse position within the widget
        *
        *  @param[out] cPickingResult
        *    Receives the picking result if all went fine
        *  @param[in]  fMaxDistance
        *    Maximum picking distance, if negative there's no maximum picking distance (in the same scene container the camera is in)
        *
        *  @return
        *    'true' if anything has been picked, else 'false'
        *
        *  @note
        *    - For performance reasons we recommend to always set a maximum picking distance
        *    - The function will only work if a widget and camera is set ('SetWidget()' and 'GetCamera()')
        */
        PL_API bool PerformMousePicking(PickingResult &cPickingResult, float fMaxDistance = -1.0f);

        /**
        *  @brief
        *    Performs picking by using the current camera and the given mouse position
        *
        *  @param[out] cPickingResult
        *    Receives the picking result if all went fine
        *  @param[in]  vMousePos
        *    Position of the mouse inside the widget the picking takes place
        *  @param[in]  fMaxDistance
        *    Maximum picking distance, if negative there's no maximum picking distance (in the same scene container the camera is in)
        *
        *  @return
        *    'true' if anything has been picked, else 'false'
        *
        *  @note
        *    - For performance reasons we recommend to always set a maximum picking distance
        *    - The function will only work if a widget and camera is set ('SetWidget()' and 'GetCamera()')
        */
        PL_API bool PerformMousePicking(PickingResult &cPickingResult, const PLMath::Vector2i &vMousePos, float fMaxDistance = -1.0f);


    //[-------------------------------------------------------]
    //[ Private functions                                     ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    Called when a camera was destroyed
        */
        void OnCameraDestroy();


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


    //[-------------------------------------------------------]
    //[ Private data                                          ]
    //[-------------------------------------------------------]
    private:
        PLCore::Frontend  *m_pFrontend; /**< Frontend instance used to determine the mouse position, always valid! */
        PLScene::SNCamera *m_pCamera;   /**< Camera to perform the picking with, can be a null pointer */


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLEngine


#endif // __PLENGINE_MOUSEPICKING_H__