QtBaseViewer.cc

/*===========================================================================*\
*                                                                            *
*                              OpenFlipper                                   *
*      Copyright (C) 2001-2011 by Computer Graphics Group, RWTH Aachen       *
*                           www.openflipper.org                              *
*                                                                            *
*--------------------------------------------------------------------------- *
*  This file is part of OpenFlipper.                                         *
*                                                                            *
*  OpenFlipper is free software: you can redistribute it and/or modify       *
*  it under the terms of the GNU Lesser General Public License as            *
*  published by the Free Software Foundation, either version 3 of            *
*  the License, or (at your option) any later version with the               *
*  following exceptions:                                                     *
*                                                                            *
*  If other files instantiate templates or use macros                        *
*  or inline functions from this file, or you compile this file and          *
*  link it with other files to produce an executable, this file does         *
*  not by itself cause the resulting executable to be covered by the         *
*  GNU Lesser General Public License. This exception does not however        *
*  invalidate any other reasons why the executable file might be             *
*  covered by the GNU Lesser General Public License.                         *
*                                                                            *
*  OpenFlipper 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             *
*  GNU Lesser General Public License for more details.                       *
*                                                                            *
*  You should have received a copy of the GNU LesserGeneral Public           *
*  License along with OpenFlipper. If not,                                   *
*  see <http://www.gnu.org/licenses/>.                                       *
*                                                                            *
\*===========================================================================*/

/*===========================================================================*\
*                                                                            *
*   $Revision$                                                       *
*   $LastChangedBy$                                                *
*   $Date$                     *
*                                                                            *
\*===========================================================================*/




//=============================================================================
//
//  CLASS glViewer - IMPLEMENTATION
//
//=============================================================================


//== INCLUDES =================================================================

#include "QtBaseViewer.hh"
#include "QtGLViewerLayout.hh"
#include "CursorPainter.hh"
#include <ACG/QtWidgets/QtWheel.hh>
#include <ACG/Scenegraph/DrawModes.hh>
#include <ACG/GL/gl.hh>

#include <iostream>
#include <string>
#include <assert.h>

#include <QMimeData>
#include <QToolButton>
#include <QFrame>

#include <QClipboard>
#include <QApplication>
#include <QSplitter>
#include <QLayout>
#include <QPushButton>
#include <QLabel>
#include <QImage>
#include <QColorDialog>
#include <QToolTip>
#include <QTextStream>
#include <QDateTime>
#include <QTimer>

#include <QDesktopWidget>
#include <QMouseEvent>
#include <QVBoxLayout>
#include <QKeyEvent>
#include <QGridLayout>
#include <QContextMenuEvent>
#include <QWheelEvent>
#include <QDropEvent>
#include <QPixmap>
#include <QMenu>
#include <QVariant>
#include <QButtonGroup>
#include <QToolBar>

#include <QGraphicsView>
#include <QGraphicsScene>
#include <QGraphicsWidget>
#include <QGraphicsGridLayout>
#include <QGraphicsProxyWidget>
#include <QGLFramebufferObjectFormat>
#include <QPainter>
#include <QPaintEngine>

#include <QImageWriter>

#ifdef max
#  undef max
#endif

#ifdef min
#  undef min
#endif

#include <OpenFlipper/BasePlugin/PluginFunctions.hh>
#include <OpenFlipper/common/ViewObjectMarker.hh>

#include <OpenFlipper/common/GlobalOptions.hh>

#include <QGLFramebufferObject>

#include <OpenFlipper/common/RendererInfo.hh>
#include <OpenFlipper/BasePlugin/PostProcessorInterface.hh>

//== NAMESPACES ===============================================================



//== IMPLEMENTATION ==========================================================

static const char          VIEW_MAGIC[] =
  "ACG::QtWidgets::QGLViewerWidget encoded view";

//== IMPLEMENTATION ==========================================================


glViewer::glViewer( QGraphicsScene* _scene,
                    QGLWidget* _glWidget,
                    Viewer::ViewerProperties& _properties,
                    QGraphicsWidget* _parent) :
  QGraphicsWidget(_parent),
  glareaGrabbed_(false),
  projectionUpdateLocked_(false),
  blending_(true),
  glScene_(_scene),
  glWidget_(_glWidget),
  cursorPainter_(0),
  cursorPositionValid_(false),
  pickCache_(0),
  updatePickCache_(true),
  pickCacheSupported_(true),
  clickEvent_(QEvent::MouseButtonPress, QPoint (), Qt::NoButton, Qt::NoButton, Qt::NoModifier),
  properties_(_properties),
  glstate_(0),
  initialized_(false),
  flyAnimationPerspective_(0),
  flyAnimationOrthogonal_(0),
  flyAngle_(0.0),
  currentAnimationPos_(0.0),
  flyMoveBack_(false)
{

  // widget stuff
  createWidgets();

  // bind GL context to GL state class
  glstate_ = new ACG::GLState();
  properties_.setglState( glstate_ );

  // state
  isRotating_       = false;
  lookAround_       = false;

  sceneGraphRoot_   = 0;

  normalsMode_      = NORMALIZE_NORMALS;
  projectionMode_   = PERSPECTIVE_PROJECTION;
  navigationMode_   = NORMAL_NAVIGATION;

  trackMouse_ = false;

  // stereo
  stereo_ = false;

  // Note: we start locked (initialization of updateLocked_)
  // will be unlocked in initializeGL()

  QSizePolicy sp = sizePolicy();
  sp.setHorizontalPolicy( QSizePolicy::Expanding );
  sp.setVerticalPolicy( QSizePolicy::Expanding );
  sp.setHorizontalStretch( 1 );
  sp.setVerticalStretch( 1 );
  setSizePolicy( sp );

  redrawTime_.start ();

  // timer for animation
  timer_ = new QTimer( this );
  connect( timer_, SIGNAL(timeout()), this, SLOT( slotAnimation()) );

  allowRotation_ = true;


  connect( &properties_,SIGNAL(updated()), this, SLOT( slotPropertiesUpdated() ) );


  //check for updated properties once
  slotPropertiesUpdated();

  setAcceptDrops(true);

  setHome();

  // initialize custom anaglyph stereo
  agTexWidth_ = 0;
  agTexHeight_ = 0;
  agTexture_[0] = 0;
  agTexture_[1] = 0;
  agProgram_ = 0;
  customAnaglyphSupported_ = false;

  clickTimer_.setSingleShot (true);
  connect (&clickTimer_, SIGNAL(timeout ()), this, SLOT(slotClickTimeout ()));
}


//-----------------------------------------------------------------------------


glViewer::~glViewer()
{
  finiCustomAnaglyphStereo ();
  delete glstate_;
}


//-----------------------------------------------------------------------------


QSize
glViewer::sizeHint() const
{
  return QSize( 600, 600 );
}

//-----------------------------------------------------------------------------


void glViewer::makeCurrent() {
  glWidget_->makeCurrent();
}

void glViewer::swapBuffers() {
  glWidget_->swapBuffers();
}


//-----------------------------------------------------------------------------


void glViewer::sceneGraph(ACG::SceneGraph::BaseNode* _root, const bool _resetTrackBall)
{
  sceneGraphRoot_ = _root;

  if (sceneGraphRoot_ )
  {
    
    // set max number of render pass
    // Single pass action, this info is static during multipass
    ACG::SceneGraph::MultiPassInfoAction info_act;
    ACG::SceneGraph::traverse(sceneGraphRoot_, info_act);
    
    glstate_->set_max_render_passes(info_act.getMaxPasses());
    
    // get scene size
    // Single pass action, as the bounding box is not influenced by multipass traversal
    ACG::SceneGraph::BoundingBoxAction act;
    ACG::SceneGraph::traverse(sceneGraphRoot_, act);

    ACG::Vec3d bbmin = (ACG::Vec3d) act.bbMin();
    ACG::Vec3d bbmax = (ACG::Vec3d) act.bbMax();
    
    

    if ( ( bbmin[0] > bbmax[0] ) ||
         ( bbmin[1] > bbmax[1] ) ||
         ( bbmin[2] > bbmax[2] )   ) {
      
      // Invalid bounding box, try to recover
      setScenePos( ACG::Vec3d( 0.0,0.0,0.0 ) , 1.0, _resetTrackBall );
    
      // Update bounding box to match the scene geometry after recovery
      bbmin = ACG::Vec3d(-1.0,-1.0,-1.0);
      bbmax = ACG::Vec3d( 1.0, 1.0, 1.0);
    } else {
      
      // For very small scenes, we set the scene radius to 0.1
      // otherwise we take the real radius
      if ( ( bbmax - bbmin ).max() < OpenFlipperSettings().value("Core/Gui/glViewer/minimalSceneSize",0.1).toDouble() )  {
        setScenePos( ( bbmin + bbmax )        * 0.5,
                     OpenFlipperSettings().value("Core/Gui/glViewer/minimalSceneSize",0.1).toDouble(),
                     _resetTrackBall);
                   
      } else {
        setScenePos( ( bbmin + bbmax )        * 0.5,
                     ( bbmax - bbmin ).norm() * 0.5,
                     _resetTrackBall); 
      }
                   
    }
                   
    // remember the new bounding box for the state
    glstate_->set_bounding_box(bbmin,bbmax);
    
  }
  

  updateGL();

  emit(signalSceneGraphChanged(sceneGraphRoot_));
}


//-----------------------------------------------------------------------------


void glViewer::trackMouse(bool _track)
{
  trackMouse_ = _track;
}


//-----------------------------------------------------------------------------

void glViewer::perspectiveProjection()
{
  projectionMode(PERSPECTIVE_PROJECTION);
  updateGL();
}


void glViewer::orthographicProjection()
{
  projectionMode(ORTHOGRAPHIC_PROJECTION);
  updateGL();
}


void glViewer::toggleProjectionMode()
{
  if (projectionMode_ == ORTHOGRAPHIC_PROJECTION)
    projectionMode(PERSPECTIVE_PROJECTION);
  else
    projectionMode(ORTHOGRAPHIC_PROJECTION);

  updateGL();
}


void glViewer::projectionMode(ProjectionMode _p)
{
  if ((projectionMode_ = _p) == ORTHOGRAPHIC_PROJECTION)
    emit projectionModeChanged( true );
  else
    emit projectionModeChanged( false );

  updateProjectionMatrix();

  emit viewChanged();
}

void glViewer::toggleNavigationMode()
{
  if (navigationMode_ == NORMAL_NAVIGATION)
    navigationMode(FIRSTPERSON_NAVIGATION);
  else
    navigationMode(NORMAL_NAVIGATION);
}


void glViewer::navigationMode(NavigationMode _n)
{
  if ((navigationMode_ = _n) == NORMAL_NAVIGATION)
    emit navigationModeChanged( true );
  else
    emit navigationModeChanged( false );
}

void glViewer::setFOVY(double _fovy) {
    
  if(_fovy <= 0.0 || _fovy >= 180) {
    std::cerr << "Error: Minimum or maximum fovy angle exceeded!" << std::endl;
    return;
  }
  
  OpenFlipperSettings().setValue("Core/Projection/FOVY", _fovy);
  updateProjectionMatrix();
}


void glViewer::updateProjectionMatrix()
{
  if( projectionUpdateLocked_ )
    return;

  makeCurrent();

  glstate_->reset_projection();

  // In stereo mode we have to use a perspective matrix
  if (stereo_ || projectionMode_ == PERSPECTIVE_PROJECTION)
  {
    double aspect;

    if (isVisible() && glWidth() && glHeight())
      aspect = (double) glWidth() / (double) glHeight();
    else
      aspect = 1.0;

    // Get fovy
    double fovy = OpenFlipperSettings().value("Core/Projection/FOVY", 45.0).toDouble();

    glstate_->perspective(fovy, (GLdouble) aspect,
                          properties_.nearPlane(), properties_.farPlane());
  }
  else
  {
    double aspect;

    if (isVisible() && glWidth() && glHeight())
      aspect = (double) glWidth() / (double) glHeight();
    else
      aspect = 1.0;

    glstate_->ortho( -properties_.orthoWidth(), properties_.orthoWidth(),
                     -properties_.orthoWidth()/aspect, properties_.orthoWidth()/aspect,
                      properties_.nearPlane(), properties_.farPlane() );
  }

}


//-----------------------------------------------------------------------------


void glViewer::setScenePos(const ACG::Vec3d& _center, double _radius, const bool _resetTrackBall)
{
  if(_resetTrackBall) {
    properties_.trackballCenter(_center);
  }

  properties_.sceneCenter(_center);

  properties_.sceneRadius(_radius);
  properties_.trackballRadius(_radius);

  ACG::Vec3d c = glstate_->modelview().transform_point(properties_.sceneCenter());

  // Set far plane
  properties_.farPlane( std::max(0.0002f * properties_.sceneRadius(),  -(c[2] - properties_.sceneRadius() )) );

  // Set near plane
  properties_.nearPlane( std::max(0.0001f * properties_.sceneRadius(),  -(c[2] + properties_.sceneRadius())) );
  
  updateProjectionMatrix();
  updateGL();

  emit viewChanged();
}


//----------------------------------------------------------------------------


void glViewer::viewingDirection( const ACG::Vec3d& _dir, const ACG::Vec3d& _up )
{
  // calc eye point for this direction
  ACG::Vec3d eye = properties_.sceneCenter() - _dir * ( 3.0 * properties_.sceneRadius());

  glstate_->reset_modelview();
  glstate_->lookAt((ACG::Vec3d)eye, (ACG::Vec3d)properties_.sceneCenter(), (ACG::Vec3d)_up);

  emit viewChanged();
}

//-----------------------------------------------------------------------------

void glViewer::lookAt(const ACG::Vec3d& _eye, const ACG::Vec3d& _center, const ACG::Vec3d& _up) {
    
    glstate_->reset_modelview();
    glstate_->lookAt(_eye, _center, _up);
    
    properties_.sceneCenter( _center );
    properties_.sceneRadius( (properties_.sceneCenter() - _eye).norm() );
    
    emit viewChanged();
}

//-----------------------------------------------------------------------------

void glViewer::normalsMode(NormalsMode _mode)
{
  makeCurrent();

  switch(normalsMode_ = _mode)
  {
    case DONT_TOUCH_NORMALS:
      ACG::GLState::disable(GL_NORMALIZE);
      break;

    case NORMALIZE_NORMALS:
      ACG::GLState::enable(GL_NORMALIZE);
      break;
  }

  updateGL();
}


//-----------------------------------------------------------------------------


void
glViewer::copyToImage( QImage& _image,
		       unsigned int _l, unsigned int _t,
		       unsigned int _w, unsigned int _h,
			     GLenum /* _buffer */ )
{

//    makeCurrent();

  _image = glWidget_->grabFrameBuffer(true).copy (_l, _t, _w, _h).convertToFormat (QImage::Format_RGB32);
}


//-----------------------------------------------------------------------------


void glViewer::updateGL()
{
  if (!properties_.updateLocked() && isVisible() )
  {
    updatePickCache_ = true;
    update();

    emit viewUpdated();
  }
}



//-----------------------------------------------------------------------------


void glViewer::drawScene()
{
  
  // Inside the glWidget rendering, the system should not send extra updates
  properties_.blockSignals(true);
  
  QTime  timer;
  timer.start();

  // *****************************************************************
  // Adjust clipping planes
  // *****************************************************************
  // Far plane
  ACG::Vec3d c = glstate_->modelview().transform_point(properties_.sceneCenter());

  // Set far plane
  properties_.farPlane( std::max(0.0002f * properties_.sceneRadius(),  -(c[2] - properties_.sceneRadius())) );

  // Set near plane
  properties_.nearPlane( std::max(0.0001f * properties_.sceneRadius(),  -(c[2] + properties_.sceneRadius())) );

  updateProjectionMatrix();

  // store time since last repaint in gl state and restart timer
  glstate_->set_msSinceLastRedraw (redrawTime_.restart ());

  // draw mono or stereo
  makeCurrent();

  // Check if we use build in default renderers
  if ( renderManager().activeId( properties_.viewerId() ) == 0 ) {
    if (stereo_) drawScene_stereo();
    else         drawScene_mono();
  } else {
    renderManager().active( properties_.viewerId() )->plugin->render(glstate_,properties_);
  }
  
  if ( postProcessorManager().activeId( properties_.viewerId() ) != 0 ) {
    postProcessorManager().active( properties_.viewerId() )->plugin->postProcess(glstate_);
  }
  
  glFinish();

  frame_time_ = timer.elapsed();

  
  // Inside the glWidget rendering, the system should not send extra updates
  properties_.blockSignals(false);

}


//-----------------------------------------------------------------------------


void glViewer::drawScene_mono()
{
  if (sceneGraphRoot_) {
    ViewObjectMarker *oM = properties_.objectMarker();
    GLuint refBits = 0;
    QSet<GLuint> references;

    if (oM)
    {
      glClear (GL_STENCIL_BUFFER_BIT);
      ACG::GLState::enable (GL_STENCIL_TEST);
      glStencilOp (GL_KEEP, GL_KEEP, GL_ZERO);
      glStencilFunc (GL_ALWAYS, 0, ~0);

      for (PluginFunctions::ObjectIterator o_it(PluginFunctions::ALL_OBJECTS, DATA_ALL) ;
          o_it != PluginFunctions::objectsEnd(); ++o_it)
      {
        bool ok;
        GLuint ref;

        ok = oM->stencilRefForObject(*o_it, ref);

        if (ok)
        {
          o_it->stencilRefNode ()->setReference (ref);
          o_it->stencilRefNode ()->show ();
          refBits |= ref;
          references << ref;
        }
        else
          o_it->stencilRefNode ()->hide ();
      }
    }

    ACG::SceneGraph::DrawAction action( properties_.drawMode(), *glstate_ , false);
    ACG::SceneGraph::traverse_multipass(sceneGraphRoot_, action, *glstate_, properties_.drawMode() );

    if( blending_ )
    {
      ACG::SceneGraph::DrawAction action(properties_.drawMode(), *glstate_, true);
      ACG::SceneGraph::traverse_multipass(sceneGraphRoot_, action, *glstate_, properties_.drawMode());
    }

    if (oM)
    {
      if (oM->type() == ViewObjectMarker::PerBit)
      {
        references.clear ();
        for (unsigned int i = 0; i < sizeof (GLuint) * 8; i++)
          if (refBits & (1 << i))
            references << (1 << i);
      }

      glPushAttrib(GL_ALL_ATTRIB_BITS);

      ACG::GLState::enable(GL_BLEND);
      ACG::GLState::disable(GL_DEPTH_TEST);
      ACG::GLState::disable(GL_LIGHTING);
      ACG::GLState::disable(GL_DITHER);

      int vp_l, vp_b, vp_w, vp_h;
      glstate_->get_viewport (vp_l, vp_b, vp_w, vp_h);

      glMatrixMode(GL_PROJECTION);
      glPushMatrix ();
      glLoadIdentity();
      glOrtho(0, vp_w, vp_h, 0, 0, 1.0);
      glMatrixMode(GL_MODELVIEW);
      glPushMatrix ();
      glLoadIdentity();

      glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP);

      foreach (unsigned int ref, references)
      {
        bool ok;
        GLenum sfactor;
        GLenum dfactor;
        ACG::Vec4f color;
        unsigned int mask = ~0;

        if (oM->type() == ViewObjectMarker::PerBit)
        {
          ok = oM->blendForStencilRefBit (ref, sfactor, dfactor, color);
          mask = ref;
        }
        else
          ok = oM->blendForStencilRefNumber (ref, sfactor, dfactor, color);

        if (!ok)
          continue;

        glStencilFunc (GL_EQUAL, ref, mask);

        ACG::GLState::blendFunc (sfactor, dfactor);
        glColor4f (color[0], color [1], color [2], color[3]);

        glBegin (GL_QUADS);
        glVertex2i(0, 0);
        glVertex2i(0, vp_h);
        glVertex2i(vp_w, vp_h);
        glVertex2i(vp_w, 0);
        glEnd ();

      }

      glMatrixMode(GL_PROJECTION);
      glPopMatrix ();
      glMatrixMode(GL_MODELVIEW);
      glPopMatrix ();

      glPopAttrib ();
      ACG::GLState::disable (GL_STENCIL_TEST);
    }


  }

  if (cursorPainter_ && cursorPainter_->enabled () && cursorPositionValid_)
  {
    glstate_->push_modelview_matrix ();
    // reset view transformation
    glstate_->reset_modelview ();
    // translate cursor position to 0,0
    glstate_->translate (cursorPoint3D_[0], cursorPoint3D_[1], cursorPoint3D_[2]);
    // paint cursor
    cursorPainter_->paintCursor (glstate_);
    glstate_->pop_modelview_matrix ();
  }

}


//-----------------------------------------------------------------------------


void
glViewer::drawScene_stereo()
{
  if (OpenFlipper::Options::stereoMode () == OpenFlipper::Options::OpenGL && OpenFlipper::Options::glStereo ())
  {
    drawScene_glStereo ();
    return;
  }
  else if (OpenFlipper::Options::stereoMode () == OpenFlipper::Options::AnaglyphCustom && customAnaglyphSupported_)
  {
    drawScene_customAnaglyphStereo ();

    // if somthing went wrong, fallback to normal anaglyph
    if (customAnaglyphSupported_)
      return;
  }

  drawScene_anaglyphStereo ();
}


//-----------------------------------------------------------------------------


void glViewer::setHome()
{
  home_modelview_          = glstate_->modelview();
  home_inverse_modelview_  = glstate_->inverse_modelview();
  homeOrthoWidth_          = properties_.orthoWidth();
  home_center_             = properties_.trackballCenter();
  home_radius_             = properties_.trackballRadius();
}


void glViewer::home()
{
  makeCurrent();
  glstate_->set_modelview(home_modelview_, home_inverse_modelview_);
  properties_.orthoWidth( homeOrthoWidth_ );
  properties_.trackballCenter( home_center_ );
  properties_.trackballRadius(home_radius_);
  updateProjectionMatrix();
  updateGL();

  emit viewChanged();

}


//-----------------------------------------------------------------------------


void glViewer::viewAll()
{
  makeCurrent();

  // update scene graph (get new bounding box and set projection right, including near and far plane)
  properties_.lockUpdate();

  // move center (in camera coords) to origin and translate in -z dir
  translate(-(glstate_->modelview().transform_point(properties_.sceneCenter()))
            - ACG::Vec3d(0.0, 0.0, 3.0 * properties_.sceneRadius()));

  properties_.orthoWidth( 1.1 * properties_.sceneRadius() );
  double aspect = (double) glWidth() / (double) glHeight();
  if (aspect > 1.0)
    properties_.orthoWidth( aspect * properties_.orthoWidth() ) ;

  sceneGraph(PluginFunctions::getSceneGraphRootNode(), true);

  properties_.unLockUpdate();
  updateProjectionMatrix();
  updateGL();

  emit viewChanged();

}


//-----------------------------------------------------------------------------


void glViewer::setView(const ACG::GLMatrixd& _modelview,
			                  const ACG::GLMatrixd& _inverse_modelview)
{
  makeCurrent();
  glstate_->set_modelview(_modelview, _inverse_modelview);
  updateGL();

  emit viewChanged();
}


//-----------------------------------------------------------------------------


void glViewer::initializeGL()
{

  // lock update
  properties_.lockUpdate();

  // init GL state
  glstate_->initialize();

  // OpenGL state
  ACG::GLState::enable(GL_DEPTH_TEST);
  ACG::GLState::enable(GL_LIGHTING);
  ACG::GLState::disable(GL_DITHER);
  ACG::GLState::shadeModel( GL_FLAT );


  projectionMode(   projectionMode_   );
  normalsMode(      normalsMode_      );

  // Update all settings which would require a redraw
  applyProperties();

  // modelview
  glstate_->translate(0.0, 0.0, -3.0);
  setHome();


  // pixel transfer
  glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
  glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
  glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  glPixelStorei(GL_PACK_ROW_LENGTH, 0);
  glPixelStorei(GL_PACK_SKIP_ROWS, 0);
  glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
  glPixelStorei(GL_PACK_ALIGNMENT, 1);


  // unlock update (we started locked)
  properties_.unLockUpdate();

  customAnaglyphSupported_ = ACG::checkExtensionSupported("GL_ARB_fragment_program") &&
                            (ACG::checkExtensionSupported("GL_ARB_texture_rectangle") ||
                             ACG::checkExtensionSupported("GL_EXT_texture_rectangle") ||
                             ACG::checkExtensionSupported("GL_NV_texture_rectangle"));

  initialized_ = true;

  if (sceneGraphRoot_)
  {
    sceneGraph(sceneGraphRoot_, true);
    viewAll ();
  }
}


//-----------------------------------------------------------------------------


void glViewer::paintGL()
{
  if (!initialized_)
    initializeGL ();

  if (!properties_.updateLocked())
  {
    ACG::Vec4f clear_color;

    properties_.lockUpdate();

    glPushAttrib (GL_ALL_ATTRIB_BITS);

    ACG::GLState::enable(GL_DEPTH_TEST);
    ACG::GLState::enable(GL_LIGHTING);
    ACG::GLState::disable(GL_DITHER);
    ACG::GLState::shadeModel( GL_FLAT );

    glMatrixMode(GL_PROJECTION);
    glPushMatrix();

    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();


    normalsMode(      normalsMode_      );

    applyProperties();

    glstate_->setState();

    glColor4f(1.0,0.0,0.0,1.0);

    // clear (stereo mode clears buffers on its own)
    if (!stereo_)
      glstate_->clearBuffers ();

    properties_.unLockUpdate();

    // draw scene
    drawScene();

    glPopMatrix();

    glMatrixMode(GL_PROJECTION);
    glPopMatrix();

    glPopAttrib ();
  }

}


//-----------------------------------------------------------------------------


void glViewer::resizeEvent(QGraphicsSceneResizeEvent *)
{
  updateProjectionMatrix();
  glstate_->viewport(scenePos().x(),
                     scene()->height () - scenePos().y() - size().height (),
                     size().width (), size().height (),
                     scene()->width (), scene()->height ());
  update();

  emit viewChanged();
}

void glViewer::moveEvent (QGraphicsSceneMoveEvent *)
{
  glstate_->viewport(scenePos().x(),
                     scene()->height () - scenePos().y() - size().height (),
                     size().width (), size().height (),
                     scene()->width (), scene()->height ());
  update();

  emit viewChanged();
}

//-----------------------------------------------------------------------------

void glViewer::encodeView(QString& _view, const QSize& _windowSize /*= QSize()*/, const int _toolBarWidth /*=-1*/)
{
  // Get current matrices
  const ACG::GLMatrixd m = glstate_->modelview();
  const ACG::GLMatrixd p = glstate_->projection();

  // Add modelview matrix to output
  _view += QString(VIEW_MAGIC) + "\n";
  _view += QString::number(m(0,0)) + " " + QString::number(m(0,1)) + " " + QString::number(m(0,2)) + " " + QString::number(m(0,3)) + "\n";
  _view += QString::number(m(1,0)) + " " + QString::number(m(1,1)) + " " + QString::number(m(1,2)) + " " + QString::number(m(1,3)) + "\n";
  _view += QString::number(m(2,0)) + " " + QString::number(m(2,1)) + " " + QString::number(m(2,2)) + " " + QString::number(m(2,3)) + "\n";
  _view += QString::number(m(3,0)) + " " + QString::number(m(3,1)) + " " + QString::number(m(3,2)) + " " + QString::number(m(3,3)) + "\n";

  // Add projection matrix to output
  _view += QString::number(p(0,0)) + " " + QString::number(p(0,1)) + " " + QString::number(p(0,2)) + " " + QString::number(p(0,3)) + "\n";
  _view += QString::number(p(1,0)) + " " + QString::number(p(1,1)) + " " + QString::number(p(1,2)) + " " + QString::number(p(1,3)) + "\n";
  _view += QString::number(p(2,0)) + " " + QString::number(p(2,1)) + " " + QString::number(p(2,2)) + " " + QString::number(p(2,3)) + "\n";
  _view += QString::number(p(3,0)) + " " + QString::number(p(3,1)) + " " + QString::number(p(3,2)) + " " + QString::number(p(3,3)) + "\n";

  // add gl width/height, current projection Mode and the ortho mode width to output
  _view += QString::number(_windowSize.width()) + " " +  QString::number(_windowSize.height()) + " "  + QString::number(_toolBarWidth)+ " " + QString::number(projectionMode_) + " " + QString::number(properties_.orthoWidth()) + "\n";
}


//----------------------------------------------------------------------------


bool glViewer::decodeView(const QString& _view, QSize *_windowSize /*= NULL*/, int* _toolBarWidth /*= NULL*/)
{
  if (_windowSize)
    *_windowSize = QSize(-1,-1);

  if (_toolBarWidth)
    *_toolBarWidth = -1;

  if (_view.left(sizeof(VIEW_MAGIC)-1) != QString(VIEW_MAGIC))
    return false;

  // Remove the magic from the string
  QString temp = _view;
  temp.remove(0,sizeof(VIEW_MAGIC));

  //Split it into its components
  QStringList split = temp.split(QRegExp("[\\n\\s]"),QString::SkipEmptyParts);

  ACG::GLMatrixd m, p;
  int            pMode;

  // Check if the number of components matches the expected size
  if ( split.size() != 37 ) {
    std::cerr << "Unable to paste view ... wrong parameter count!! is" <<  split.size()  << std::endl;
    return false;
  }

  // Parse the components
  bool ok = true;;

  m(0,0) = split[0].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(0,1) = split[1].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(0,2) = split[2].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(0,3) = split[3].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(1,0) = split[4].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(1,1) = split[5].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(1,2) = split[6].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(1,3) = split[7].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(2,0) = split[8].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(2,1) = split[9].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(2,2) = split[10].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(2,3) = split[11].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(3,0) = split[12].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(3,1) = split[13].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(3,2) = split[14].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  m(3,3) = split[15].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(0,0) = split[16].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(0,1) = split[17].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(0,2) = split[18].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(0,3) = split[19].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(1,0) = split[20].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(1,1) = split[21].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(1,2) = split[22].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(1,3) = split[23].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(2,0) = split[24].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(2,1) = split[25].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(2,2) = split[26].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(2,3) = split[27].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(3,0) = split[28].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(3,1) = split[29].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(3,2) = split[30].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  p(3,3) = split[31].toDouble(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }

  if (_windowSize)
  {
    //restore the old window size
    int w =  split[32].toInt(&ok);
    if ( !ok )
    {
      std::cerr << "No window size saved!" << std::endl;
    }

    int h =  split[33].toInt(&ok);
    if ( !ok )
    {
      std::cerr << "No window size saved!" << std::endl;
    }

    *_windowSize = QSize(w,h);
  }

  if (_toolBarWidth)
  {
    *_toolBarWidth = split[34].toInt(&ok);
    if ( !ok )
    {
      std::cerr << "No toolbar width saved!" << std::endl;
    }
  }

  pMode =  split[35].toInt(&ok); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }
  properties_.orthoWidth( split[36].toDouble(&ok) ); if ( !ok ) { std::cerr << "Error in decoding View!" << std::endl; return false; }

  // Switch to our gl context
  makeCurrent();

  // set projection mode
  if (projectionMode_ != (ProjectionMode)pMode)
    projectionMode((ProjectionMode)pMode);

  // Apply new modelview matrix
  glstate_->set_modelview(m);

  updateGL();

  return true;
}


//-----------------------------------------------------------------------------


void glViewer::actionCopyView(const QSize &_windowSize /*= QSize(-1,-1)*/, const int _toolBarWidth /*= -1*/)
{
  QString view;
  encodeView(view,_windowSize,_toolBarWidth);
  QApplication::clipboard()->setText(view);
}


//-----------------------------------------------------------------------------


void glViewer::actionPasteView(QSize * _windowSize /*= NULL*/, int *_toolBarWidth /*= NULL*/)
{
  QString view;
  view = QApplication::clipboard()->text();
  decodeView(view,_windowSize,_toolBarWidth);
}


//-----------------------------------------------------------------------------

void
glViewer::createWidgets()
{
  // Construct GL context & widget