/* -*-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.
*/

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

using namespace osgViewer;

Scene::Scene():
    _firstFrame(true)
{
    _frameStamp = new osg::FrameStamp;
    _frameStamp->setFrameNumber(0);
    _frameStamp->setReferenceTime(0);

    _updateVisitor = new osgUtil::UpdateVisitor;
    _updateVisitor->setFrameStamp(_frameStamp.get());
    
    setDatabasePager(new osgDB::DatabasePager);
}

Scene::~Scene()
{
}

void Scene::setFrameStamp(osg::FrameStamp* frameStamp)
{
    _frameStamp = frameStamp;
    _updateVisitor->setFrameStamp(_frameStamp.get());
}

void Scene::init()
{
    osg::notify(osg::NOTICE)<<"Scene::init() not implementated yet."<<std::endl;
}


void Scene::setSceneData(osg::Node* node)
{
    _sceneData = node;
    
    if (_databasePager.valid())
    {    
        // register any PagedLOD that need to be tracked in the scene graph
        _databasePager->registerPagedLODs(node);
    }
}

osg::Node* Scene::getSceneData()
{
    return _sceneData.get();
}

const osg::Node* Scene::getSceneData() const
{
    return _sceneData.get();
}

void Scene::setDatabasePager(osgDB::DatabasePager* dp)
{
    _databasePager = dp;
}

void Scene::frameAdvance()
{
    // double previousTime = _frameStamp->getReferenceTime();
    
    _frameStamp->setReferenceTime(osg::Timer::instance()->time_s());
    _frameStamp->setFrameNumber(_frameStamp->getFrameNumber()+1);
    
    // osg::notify(osg::NOTICE)<<"Frame rate = "<<1.0/(_frameStamp->getReferenceTime()-previousTime)<<std::endl;
}

void Scene::frameUpdateTraversal()
{
    if (!getSceneData()) return;
    
    _updateVisitor->setTraversalNumber(_frameStamp->getFrameNumber());
    
    getSceneData()->accept(*_updateVisitor);
    
    if (_databasePager.valid())
    {    
        // syncronize changes required by the DatabasePager thread to the scene graph
        _databasePager->updateSceneGraph(_frameStamp->getReferenceTime());
    }
}