/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
 *
 * This application is open source and may be redistributed and/or modified   
 * freely and without restriction, both in commericial and non commericial applications,
 * as long as this copyright notice is maintained.
 * 
 * This application 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.
*/

#include <osgDB/ReadFile>
#include <osgUtil/Optimizer>
#include <osgViewer/Viewer>
#include <iostream>

int main( int argc, char **argv )
{
    // use an ArgumentParser object to manage the program arguments.
    osg::ArgumentParser arguments(&argc,argv);

    // read the scene from the list of file specified commandline args.
    osg::ref_ptr<osg::Node> loadedModel = osgDB::readNodeFiles(arguments);

    // if not loaded assume no arguments passed in, try use default mode instead.
    if (!loadedModel) loadedModel = osgDB::readNodeFile("cow.osg");
    
    // if no model has been successfully loaded report failure.
    if (!loadedModel) 
    {
        std::cout << arguments.getApplicationName() <<": No data loaded" << std::endl;
        return 1;
    }

    // construct the viewer.
    osgViewer::Viewer viewer;

    // left window + left slave camera
    {
        osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
        traits->x = 0;
        traits->y = 0;
        traits->width = 640;
        traits->height = 480;
        traits->windowDecoration = true;
        traits->doubleBuffer = true;
        traits->sharedContext = 0;

        osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());

        osg::ref_ptr<osg::Camera> camera = new osg::Camera;
        camera->setGraphicsContext(gc.get());
        camera->setViewport(new osg::Viewport(0,0, traits->width, traits->height));
        GLenum buffer = traits->doubleBuffer ? GL_BACK : GL_FRONT;
        camera->setDrawBuffer(buffer);
        camera->setReadBuffer(buffer);

        // add this slave camra to the viewer, with a shift left of the projection matrix
        viewer.addSlave(camera.get(), osg::Matrixd::translate(1.0,0.0,0.0), osg::Matrixd());
    }
    
    // left window + left slave camera
    {
        osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
        traits->x = 640;
        traits->y = 0;
        traits->width = 640;
        traits->height = 480;
        traits->windowDecoration = true;
        traits->doubleBuffer = true;
        traits->sharedContext = 0;

        osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());

        osg::ref_ptr<osg::Camera> camera = new osg::Camera;
        camera->setGraphicsContext(gc.get());
        camera->setViewport(new osg::Viewport(0,0, traits->width, traits->height));
        GLenum buffer = traits->doubleBuffer ? GL_BACK : GL_FRONT;
        camera->setDrawBuffer(buffer);
        camera->setReadBuffer(buffer);

        // add this slave camra to the viewer, with a shift right of the projection matrix
        viewer.addSlave(camera.get(), osg::Matrixd::translate(-1.0,0.0,0.0), osg::Matrixd());
    }


    // optimize the scene graph, remove rendundent nodes and state etc.
    osgUtil::Optimizer optimizer;
    optimizer.optimize(loadedModel.get());

    // set the scene to render
    viewer.setSceneData(loadedModel.get());

    return viewer.run();
}