/* -*-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_VIEW
#define OSGVIEWER_VIEW 1

#include <osg/View>

#include <osgUtil/PolytopeIntersector>
#include <osgUtil/LineSegmentIntersector>
#include <osgUtil/SceneView>

#include <osgGA/MatrixManipulator>
#include <osgViewer/Scene>

namespace osgViewer {

class OSGVIEWER_EXPORT EndOfDynamicDrawBlock : public osg::State::DynamicObjectRenderingCompletedCallback
{
    public:
    
        EndOfDynamicDrawBlock(unsigned int);
    
        void completed(osg::State* state);

        void block();
        
        void reset();

        void release();

        void setNumOfBlocks(unsigned int blockCount);

    protected:

        ~EndOfDynamicDrawBlock();

        OpenThreads::Mutex _mut;
        OpenThreads::Condition _cond;
        unsigned int _numberOfBlocks;
        unsigned int _blockCount;
};


/** View holds a single view on a scene, this view may be composed of one or more slave cameras.*/
class OSGVIEWER_EXPORT View : public osg::View, public osgGA::GUIActionAdapter
{
    public:

        View();

        View(const osgViewer::View& view, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);

        META_Object(osgViewer,View);

        Scene* getScene() { return _scene.get(); }
        const Scene* getScene() const { return _scene.get(); }

        /** Set the scene graph that the View will use.*/
        virtual void setSceneData(osg::Node* node);

        /** Get the View's scene graph.*/
        osg::Node* getSceneData() { return _scene.valid() ? _scene->getSceneData() : 0; }

        /** Get the const View's scene graph.*/
        const osg::Node* getSceneData() const { return _scene.valid() ? _scene->getSceneData() : 0; }

        /* Set the EventQueue that View uses to intregrate external non window related events.*/
        void setEventQueue(osgGA::EventQueue* eventQueue) { _eventQueue = eventQueue; }

        /* Get the View's EventQueue.*/
        osgGA::EventQueue* getEventQueue() { return _eventQueue.get(); }

        /* Get the const View's EventQueue.*/
        const osgGA::EventQueue* getEventQueue() const { return _eventQueue.get(); }

        /** Set the CameraManipulator that moves the View's master Camera position in response to events.*/
        void setCameraManipulator(osgGA::MatrixManipulator* manipulator);

        /** Get the View's CameraManipulator.*/
        osgGA::MatrixManipulator* getCameraManipulator() { return _cameraManipulator.get(); }

        /** Get the const View's CameraManipulator.*/
        const osgGA::MatrixManipulator* getCameraManipulator() const { return _cameraManipulator.get(); }

        /** Set the view to the CameraManipulator's home position, if non is attached home() is does nothing.
          * Note, to set the home position use getCamaraManipulator()->setHomePosition(...). */
        void home();
        

        typedef std::list< osg::ref_ptr<osgGA::GUIEventHandler> > EventHandlers;
        
        /** Add an EventHandler that adds handling of events to the View.*/
        void addEventHandler(osgGA::GUIEventHandler* eventHandler);

        /** Get the View's list of EventHandlers.*/
        EventHandlers& getEventHandlers() { return _eventHandlers; }

        /** Get the const View's list of EventHandlers.*/
        const EventHandlers& getEventHandlers() const { return _eventHandlers; }
        

        /** Set the NodePath to any active CoordinateSystemNode present in the Scene.
          * The CoordinateSystemNode path is used to help applications and CamaraManipualtors handle geocentric coordinates systems,
          * such as known which way is the local up at any position on the a whole earth. */
        void setCoordinateSystemNodePath(const osg::NodePath& nodePath);

        /** Get the NodePath to any active CoordinateSystemNode present in the Scene.*/
        osg::NodePath getCoordinateSystemNodePath() const;

        /** Compute the NodePath to any active CoordinateSystemNode present in the Scene.*/
        void computeActiveCoordinateSystemNodePath();

        
        /** Set the DsplaySettings object associated with this view.*/
        void setDisplaySettings(osg::DisplaySettings* ds) { _displaySettings = ds; }
        
        /** Set the DsplaySettings object associated with this view.*/
        osg::DisplaySettings* getDisplaySettings() { return _displaySettings.get(); }
        
        /** Set the DsplaySettings object associated with this view.*/
        const osg::DisplaySettings* getDisplaySettings() const { return _displaySettings.get(); }

        /** Set the FusionDistanceMode and Value. Note, is used only when working in stereo.*/
        void setFusionDistance(osgUtil::SceneView::FusionDistanceMode mode,float value=1.0f)
        {
            _fusionDistanceMode = mode;
            _fusionDistanceValue = value;
        }

        /** Get the FusionDistanceMode.*/
        osgUtil::SceneView::FusionDistanceMode getFusionDistanceMode() const { return _fusionDistanceMode; }

        /** Get the FusionDistanceValue. Note, only used for USE_FUSION_DISTANCE_VALUE & PROPORTIONAL_TO_SCREEN_DISTANCE modes.*/
        float getFusionDistanceValue() const { return _fusionDistanceValue; }

        
        /** Convinience method for creating slave Cameras and associated GraphicsWindows across all screens.*/
        void setUpViewAcrossAllScreens();

        /** Convinience method for a single Camara on a single window.*/
        void setUpViewInWindow(int x, int y, int width, int height, unsigned int screenNum=0);

        /** Convinience method for a single Camara associated with a single full screen GraphicsWindow.*/
        void setUpViewOnSingleScreen(unsigned int screenNum=0);
        
        
        /** Return true if this view contains a specified camera.*/
        bool containsCamera(const osg::Camera* camera) const;
        
        /** Get the camera which contains the pointer position x,y specified master cameras window/eye coords.
          * Also passes back the local window coords for the graphics context associated with the camera passed back. */
        const osg::Camera* getCameraContainingPosition(float x, float y, float& local_x, float& local_y) const;
        
        /** Compute intersections between a ray through the specified master cameras window/eye coords and a specified node.
          * Note, when a master cameras has slaves and no viewport itself its coordinate frame will be in clip space i.e. -1,-1 to 1,1,
          * while if its has a viewport the coordintates will be relative to its viewport dimensions. 
          * Mouse events handled by the view will automatically be attached into the master camera window/clip coords so can be passed
          * directly on to the computeIntersections method. */
        bool computeIntersections(float x,float y, osgUtil::LineSegmentIntersector::Intersections& intersections,osg::Node::NodeMask traversalMask = 0xffffffff);
        
        /** Compute intersections between a ray through the specified master cameras window/eye coords and a specified nodePath's subgraph. */
        bool computeIntersections(float x,float y, osg::NodePath& nodePath, osgUtil::LineSegmentIntersector::Intersections& intersections,osg::Node::NodeMask traversalMask = 0xffffffff);
        
        
        virtual void requestRedraw();
        virtual void requestContinuousUpdate(bool needed=true);
        virtual void requestWarpPointer(float x,float y);
        
        

    public:
        
        void assignSceneDataToCameras();
        void init();

    protected:
    

        virtual ~View();

        osg::ref_ptr<osgViewer::Scene>          _scene;
        osg::ref_ptr<osgGA::EventQueue>         _eventQueue;
        osg::ref_ptr<osgGA::MatrixManipulator>  _cameraManipulator;
        EventHandlers                           _eventHandlers;
    
        typedef std::vector< osg::observer_ptr<osg::Node> >   ObserveredNodePath;
        ObserveredNodePath                      _coordinateSystemNodePath;

        osg::ref_ptr<osg::DisplaySettings>      _displaySettings;
        osgUtil::SceneView::FusionDistanceMode  _fusionDistanceMode;
        float                                   _fusionDistanceValue;
};

}

#endif
