/*  -*-c++-*- 
 *  Copyright (C) 2008 Cedric Pinson <mornifle@plopbyte.net>
 *
 * 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 <iostream>
#include <osg/Geometry>
#include <osg/MatrixTransform>
#include <osg/Geode>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgGA/TrackballManipulator>
#include <osgGA/StateSetManipulator>
#include <osgUtil/SmoothingVisitor>
#include <osg/io_utils>

#include <osgAnimation/MorphGeometry>
#include <osgAnimation/BasicAnimationManager>

#include <osgDB/ReadFile>
#include <osgDB/WriteFile>

struct GeometryFinder : public osg::NodeVisitor
{
    osg::ref_ptr<osg::Geometry> _geom;
    GeometryFinder() : osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN) {}
    void apply(osg::Geode& geode) 
    {
        if (_geom.valid())
            return;
        for (unsigned int i = 0; i < geode.getNumDrawables(); i++) 
        {
            osg::Geometry* geom = dynamic_cast<osg::Geometry*>(geode.getDrawable(i));
            if (geom) {
                _geom = geom;
                return;
            }
        }
    }
};

osg::Geometry* getShape(const std::string& name)
{
    osg::Node* shape0 = osgDB::readNodeFile(name);
    GeometryFinder finder;
    shape0->accept(finder);
    return finder._geom.get();
}


int main (int argc, char* argv[])
{
    osg::ArgumentParser arguments(&argc, argv);
    osgViewer::Viewer viewer(arguments);

    osgAnimation::Animation* animation = new osgAnimation::Animation;
    osgAnimation::FloatLinearChannel* channel0 = new osgAnimation::FloatLinearChannel;
    channel0->getOrCreateSampler()->getOrCreateKeyframeContainer()->push_back(osgAnimation::FloatKeyframe(0,0.0));
    channel0->getOrCreateSampler()->getOrCreateKeyframeContainer()->push_back(osgAnimation::FloatKeyframe(1,1.0));
    channel0->setTargetName("MorphNodeCallback");
    channel0->setName("0");

    animation->addChannel(channel0);
    animation->setName("Morph");
    animation->computeDuration();
    animation->setPlaymode(osgAnimation::Animation::PPONG);
    osgAnimation::BasicAnimationManager* bam = new osgAnimation::BasicAnimationManager;
    bam->registerAnimation(animation);

    osg::Geometry* geom0 = getShape("morphtarget_shape0.osg");
    if (!geom0) {
        std::cerr << "can't read morphtarget_shape0.osg" << std::endl;
        return 0;
    }

    osg::Geometry* geom1 = getShape("morphtarget_shape1.osg");
    if (!geom1) {
        std::cerr << "can't read morphtarget_shape1.osg" << std::endl;
        return 0;
    }

    // initialize with the first shape
    osgAnimation::MorphGeometry* morph = new osgAnimation::MorphGeometry(*geom0);
    morph->addMorphTarget(geom1);

    viewer.setCameraManipulator(new osgGA::TrackballManipulator());


    osg::Group* scene = new osg::Group;
    scene->addUpdateCallback(bam);
    
    osg::Geode* geode = new osg::Geode;
    geode->addDrawable(morph);
    geode->addUpdateCallback(new osgAnimation::UpdateMorph("MorphNodeCallback"));
    scene->addChild(geode);

    viewer.addEventHandler(new osgViewer::StatsHandler());
    viewer.addEventHandler(new osgViewer::WindowSizeHandler());
    viewer.addEventHandler(new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()));

    // let's run !
    viewer.setSceneData( scene );
    viewer.realize();

    bam->playAnimation(animation);


    while (!viewer.done())
    {
        viewer.frame();
    }

    osgDB::writeNodeFile(*scene, "morph_scene.osg");

    return 0;
}