/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library 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 
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSGVIEWER_CompositeViewer
#define OSGVIEWER_CompositeViewer 1

#include <osgViewer/GraphicsWindow>
#include <osgViewer/View>

namespace osgViewer {

/** CompsiteViewer holds a or more views to a one more scenes.*/
class OSGVIEWER_EXPORT CompositeViewer : public osg::Referenced
{
    public:

        CompositeViewer();
        virtual ~CompositeViewer();

        void addView(osgViewer::View* view);
        
        osgViewer::View* getView(unsigned i) { return _views[i].get(); }
        const osgViewer::View* getView(unsigned i) const { return _views[i].get(); }
        
        unsigned int getNumViews() const { return _views.size(); }

        
        /** Get whether at least of one of this viewers windows are realized.*/
        bool isRealized() const;

        /** set up windows and associated threads.*/
        void realize();

        void setDone(bool done) { _done = done; }
        
        bool done() const { return _done; }
        
        void setStartTick(osg::Timer_t tick);
        osg::Timer_t getStartTick() const { return _startTick; }

        void setReferenceTime(double time=0.0);

        osg::FrameStamp* getFrameStamp() { return _frameStamp.get(); }
        const osg::FrameStamp* getFrameStamp() const { return _frameStamp.get(); }

        enum ThreadingModel
        {
            SingleThreaded,
            ThreadPerContext,
            ThreadPerCamera
        };
        
        /** Set the threading model the rendering traversals will use.*/
        void setThreadingModel(ThreadingModel threadingModel);
        
        /** Get the threading model the rendering traversals will use.*/
        ThreadingModel getThreadingModel() const { return _threadingModel; }

        enum BarrierPosition
        {
            BeforeSwapBuffers,
            AfterSwapBuffers
        };
        
        /** Set the position of the end barrier.
          * AfterSwapBuffers will may result is slightly higher framerates, by may
          * lead to inconcistent swapping between different windows.
          * BeforeSwapBuffers may lead to slightly lower framerate, but improve consistency in timing of swap buffers,
          * especially important if you are likely to consistently break frame.*/
        void setEndBarrierPosition(BarrierPosition bp);

        /** Get the end barrier position.*/
        BarrierPosition getEndBarrierPosition() const { return _endBarrierPosition; }

        void setEventQueue(osgGA::EventQueue* eventQueue) { _eventQueue = eventQueue; }
        osgGA::EventQueue* getEventQueue() { return _eventQueue.get(); }
        const osgGA::EventQueue* getEventQueue() const { return _eventQueue.get(); }

        /** Set the key event that the viewer checks on each frame to see if the viewer's done flag should be set to
          * signal end of viewers main loop.
          * Default value is Escape (osgGA::GUIEVentAdapter::KEY_Escape).
          * Setting to 0 switches off the feature.*/
        void setKeyEventSetsDone(int key) { _keyEventSetsDone = key; }

        /** get the key event that the viewer checks on each frame to see if the viewer's done flag.*/
        int getKeyEventSetsDone() const { return _keyEventSetsDone; }
        
        /** if the flag is true, the viewer set its done flag when a QUIT_APPLICATION is received, false disables this feature */
        void setQuitEventSetsDone(bool flag) { _quitEventSetsDone = flag; }
        
        /** @return true if the viewer respond to the QUIT_APPLICATION-event */
        bool getQuitEventSetsDone() const { return _quitEventSetsDone; }

        /** Execute a main frame loop.
          * Equivialant to while (!viewer.done()) viewer.frame();
          * Also calls realize() if the viewer is not already realized,
          * and installs trackball manipulator if one is not already assigned.
          */
        virtual int run();

        /** Render a complete new frame.
          * Calls advance(), eventTraversal(), updateTraversal(), renderingTraversals(). */
        virtual void frame(double simulationTime=USE_REFERENCE_TIME);

        virtual void advance(double simulationTime=USE_REFERENCE_TIME);

        virtual void eventTraversal();

        virtual void updateTraversal();
        
        virtual void renderingTraversals();

        
        void setCameraWithFocus(osg::Camera* camera);
        osg::Camera* getCameraWithFocus() { return _cameraWithFocus.get(); }
        const osg::Camera* getCameraWithFocus() const { return _cameraWithFocus.get(); }
        
        osgViewer::View* getViewWithFocus() { return _viewWithFocus.get(); }
        const osgViewer::View* getViewWithFocus() const { return _viewWithFocus.get(); }
        
        typedef std::vector<osg::GraphicsContext*> Contexts;
        void getContexts(Contexts& contexts, bool onlyValid=true);
        
        typedef std::vector<osgViewer::GraphicsWindow*> Windows;
        void getWindows(Windows& windows, bool onlyValid=true);

        typedef std::vector<osgViewer::Scene*> Scenes;
        void getScenes(Scenes& scenes, bool onlyValid=true);


        /** Set the graphics operation to call on realization of the viewers graphics windows.*/
        void setRealizeOperation(osg::Operation* op) { _realizeOperation = op; }

        /** Get the graphics operation to call on realization of the viewers graphics windows.*/
        osg::Operation* getRealizeOperation() { return _realizeOperation.get(); }

        /** Stop any threads begin run by viewer.*/
        void stopThreading();

        /** Start any threads required by the viewer, as per viewers ThreadingModel.*/
        void startThreading();        

        /** Set up the Operations to render the various viewer cameras on the viewers graphics windows.*/
        void setUpRenderingSupport();


    protected:

        void init();
        void checkWindowStatus();

        typedef std::vector< osg::ref_ptr<osgViewer::View> > Views;
        Views _views;
       
        bool _firstFrame;
        
        bool _done;
        int _keyEventSetsDone;
        bool _quitEventSetsDone;
        
        ThreadingModel _threadingModel;
        BarrierPosition _endBarrierPosition;

        osg::ref_ptr<osg::BarrierOperation> _startRenderingBarrier;
        osg::ref_ptr<osg::BarrierOperation> _endRenderingDispatchBarrier;

        unsigned int computeNumberOfThreadsIncludingMainRequired();

        unsigned int _numThreadsOnBarrier;
        
        typedef std::map<osg::ref_ptr<osg::Camera>, osg::ref_ptr<osgUtil::SceneView> > CameraSceneViewMap;
        CameraSceneViewMap _cameraSceneViewMap;

        osg::Timer_t                        _startTick;
        osg::ref_ptr<osg::FrameStamp>       _frameStamp;

        osg::observer_ptr<osg::Camera>      _cameraWithFocus;
        osg::observer_ptr<osgViewer::View>  _viewWithFocus;
        
        osg::ref_ptr<osgGA::EventQueue>     _eventQueue;
        osg::ref_ptr<osgGA::EventVisitor>   _eventVisitor;

        osg::ref_ptr<osg::Operation>        _realizeOperation;
};


}

#endif