/* OpenSceneGraph example, osgtexture3D.
*
*  Permission is hereby granted, free of charge, to any person obtaining a copy
*  of this software and associated documentation files (the "Software"), to deal
*  in the Software without restriction, including without limitation the rights
*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
*  copies of the Software, and to permit persons to whom the Software is
*  furnished to do so, subject to the following conditions:
*
*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
*  THE SOFTWARE.
*/

#include <osg/Node>
#include <osg/Geometry>
#include <osg/Notify>
#include <osg/Texture2D>
#include <osg/TexGen>
#include <osg/Geode>

#include <osgDB/ReadFile>

#include <osgText/Text>

#include <osgGA/TrackballManipulator>
#include <osgViewer/CompositeViewer>

#include <iostream>

osg::Camera* createHUD(const std::string& label)
{
    // create a camera to set up the projection and model view matrices, and the subgraph to drawn in the HUD
    osg::Camera* camera = new osg::Camera;

    // set the projection matrix
    camera->setProjectionMatrix(osg::Matrix::ortho2D(0,1280,0,1024));

    // set the view matrix    
    camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
    camera->setViewMatrix(osg::Matrix::identity());

    // only clear the depth buffer
    camera->setClearMask(GL_DEPTH_BUFFER_BIT);

    // draw subgraph after main camera view.
    camera->setRenderOrder(osg::Camera::POST_RENDER);

    // we don't want the camera to grab event focus from the viewers main camera(s).
    camera->setAllowEventFocus(false);

    // add to this camera a subgraph to render
    {

        osg::Geode* geode = new osg::Geode();

        std::string font("fonts/arial.ttf");

        // turn lighting off for the text and disable depth test to ensure its always ontop.
        osg::StateSet* stateset = geode->getOrCreateStateSet();
        stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);

        osg::Vec3 position(150.0f,150.0f,0.0f);

        osgText::Text* text = new  osgText::Text;
        geode->addDrawable( text );

        text->setFont(font);
        text->setPosition(position);
        text->setCharacterSize(100.0f);
        text->setText(label);

        camera->addChild(geode);
    }

    return camera;
}

osg::Node* creatQuad(const std::string& name, 
                     osg::Image* image, 
                     osg::Texture::InternalFormatMode formatMode,
                     osg::Texture::FilterMode minFilter)
{

    osg::Group* group = new osg::Group;
    
    {
        osg::Geode* geode = new osg::Geode;

        geode->addDrawable(createTexturedQuadGeometry(
                osg::Vec3(0.0f,0.0f,0.0f),
                osg::Vec3(float(image->s()),0.0f,0.0f),
                osg::Vec3(0.0f,0.0f,float(image->t()))));

        geode->setName(name);

        osg::StateSet* stateset = geode->getOrCreateStateSet();

        osg::Texture2D* texture = new osg::Texture2D(image);
        texture->setInternalFormatMode(formatMode);
        texture->setFilter(osg::Texture::MIN_FILTER, minFilter);
        stateset->setTextureAttributeAndModes(0, texture, osg::StateAttribute::ON);
        
        group->addChild(geode);
    }
    
    {
        group->addChild(createHUD(name));
    }
    
    return group;
}

int main(int argc, char** argv)
{
    osg::ArgumentParser arguments(&argc, argv);

    // construct the viewer.
    osgViewer::CompositeViewer viewer(arguments);
    
    if (arguments.argc()<=1)
    {
        std::cout<<"Please supply an image filename on the commnand line."<<std::endl;
        return 1;
    }
    
    std::string filename = arguments[1];
    osg::ref_ptr<osg::Image> image = osgDB::readImageFile(filename);
    
    if (!image)
    {
        std::cout<<"Error: unable able to read image from "<<filename<<std::endl;
        return 1;
    }

    osg::GraphicsContext::WindowingSystemInterface* wsi = osg::GraphicsContext::getWindowingSystemInterface();
    if (!wsi) 
    {
        osg::notify(osg::NOTICE)<<"Error, no WindowSystemInterface available, cannot create windows."<<std::endl;
        return 1;
    }


    unsigned int width, height;
    wsi->getScreenResolution(osg::GraphicsContext::ScreenIdentifier(0), width, height);

    osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
    traits->x = 0;
    traits->y = 0;
    traits->width = width;
    traits->height = height;
    traits->windowDecoration = false;
    traits->doubleBuffer = true;
    
    osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());
    if (!gc)
    {
        std::cout<<"Error: GraphicsWindow has not been created successfully."<<std::endl;
    }

    gc->setClearColor(osg::Vec4(0.0f,0.0f,0.0f,1.0f));
    gc->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    osg::ref_ptr<osgGA::TrackballManipulator> trackball = new osgGA::TrackballManipulator;
    
    typedef std::vector< osg::ref_ptr<osg::Node> > Models;
    
    Models models;
    models.push_back(creatQuad("no compression", image.get(), osg::Texture::USE_IMAGE_DATA_FORMAT, osg::Texture::LINEAR));
    models.push_back(creatQuad("ARB compression", image.get(), osg::Texture::USE_ARB_COMPRESSION, osg::Texture::LINEAR));
    models.push_back(creatQuad("DXT1 compression", image.get(), osg::Texture::USE_S3TC_DXT1_COMPRESSION, osg::Texture::LINEAR));
    models.push_back(creatQuad("DXT3 compression", image.get(), osg::Texture::USE_S3TC_DXT3_COMPRESSION, osg::Texture::LINEAR));
    models.push_back(creatQuad("DXT5 compression", image.get(), osg::Texture::USE_S3TC_DXT5_COMPRESSION, osg::Texture::LINEAR));
    
    int numX = 1;
    int numY = 1;

    // compute the number of views up and across that are need
    {
        float aspectRatio = float(width)/float(height);
        float multiplier = sqrtf(float(models.size())/aspectRatio);;
        float multiplier_x = multiplier*aspectRatio;
        float multiplier_y = multiplier;


        if ((multiplier_x/ceilf(multiplier_x)) > (multiplier_y/ceilf(multiplier_y)))
        {
            numX = int(ceilf(multiplier_x));
            numY = int(ceilf(float(models.size())/float(numX)));
        }
        else
        {
            numY = int(ceilf(multiplier_y));
            numX = int(ceilf(float(models.size())/float(numY)));
        }
    }

    // populate the view with the required view to view each model.
    for(unsigned int i=0; i<models.size(); ++i)
    {
        osgViewer::View* view = new osgViewer::View;
        
        int xCell = i % numX;
        int yCell = i / numX;
    
        int vx = int((float(xCell)/float(numX)) * float(width));
        int vy = int((float(yCell)/float(numY)) * float(height));
        int vw =  int(float(width) / float(numX));
        int vh =  int(float(height) / float(numY));

        view->setSceneData(models[i].get());
        view->getCamera()->setProjectionMatrixAsPerspective(30.0, double(vw) / double(vh), 1.0, 1000.0);
        view->getCamera()->setViewport(new osg::Viewport(vx, vy, vw, vh));    
        view->getCamera()->setGraphicsContext(gc.get());
        view->getCamera()->setClearMask(0);
        view->setCameraManipulator(trackball.get());

        viewer.addView(view);
    }

    return viewer.run();
}