qglviewerwidget.cc

penMesh is a generic and efficient data structure for representing and manipulating polygonal meshes

void QGLViewerWidget::wheelEvent(QWheelEvent* _event)
{
  // Use the mouse wheel to zoom in/out

  float d = -(float)_event->delta() / 120.0 * 0.2 * radius_;
  translate(Vec3f(0.0, 0.0, d));
  updateGL();
  _event->accept();
}


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


void QGLViewerWidget::keyPressEvent( QKeyEvent* _event)
{
  switch( _event->key() )
  {
    case Key_Print:
      slotSnapshot();
      break;

    case Key_H:
      std::cout << "Keys:\n";
      std::cout << "  Print\tMake snapshot\n";
      std::cout << "  C\tenable/disable back face culling\n";
      std::cout << "  F\tenable/disable fog\n";
      std::cout << "  I\tDisplay information\n";
      std::cout << "  N\tenable/disable display of vertex normals\n";
      std::cout << "  Shift N\tenable/disable display of face normals\n";
      std::cout << "  Shift P\tperformance check\n";
      break;

    case Key_C:
      if ( glIsEnabled( GL_CULL_FACE ) )
      {
	glDisable( GL_CULL_FACE );
	std::cout << "Back face culling: disabled\n";
      }
      else
      {
	glEnable( GL_CULL_FACE );
	std::cout << "Back face culling: enabled\n";
      }
      updateGL();
      break;

    case Key_F:
      if ( glIsEnabled( GL_FOG ) )
      {
	glDisable( GL_FOG );
	std::cout << "Fog: disabled\n";
      }
      else
      {
	glEnable( GL_FOG );
	std::cout << "Fog: enabled\n";
      }
      updateGL();
      break;

    case Key_I:
      std::cout << "Scene radius: " << radius_ << std::endl;
      std::cout << "Scene center: " << center_ << std::endl;
      break;

    case Key_P:
      if (_event->state() & ShiftButton)
      {
        double fps = performance();      
        std::cout << "fps: " 
                  << std::setiosflags (std::ios_base::fixed)
                  << fps << std::endl;
      }
    break;
    
    case Key_Q:
    case Key_Escape:
      qApp->quit();      
  }
  _event->ignore();
}


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


void
QGLViewerWidget::translate( const Vec3f& _trans )
{
  // Translate the object by _trans
  // Update modelview_matrix_
  makeCurrent();
  glLoadIdentity();
  glTranslated( _trans[0], _trans[1], _trans[2] );
  glMultMatrixd( modelview_matrix_ );
  glGetDoublev( GL_MODELVIEW_MATRIX, modelview_matrix_);
}


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


void
QGLViewerWidget::rotate( const Vec3f& _axis, float _angle )
{
  // Rotate around center center_, axis _axis, by angle _angle
  // Update modelview_matrix_

  Vec3f t( modelview_matrix_[0]*center_[0] + 
	   modelview_matrix_[4]*center_[1] +
	   modelview_matrix_[8]*center_[2] + 
	   modelview_matrix_[12],
	   modelview_matrix_[1]*center_[0] + 
	   modelview_matrix_[5]*center_[1] +
	   modelview_matrix_[9]*center_[2] + 
	   modelview_matrix_[13],
	   modelview_matrix_[2]*center_[0] + 
	   modelview_matrix_[6]*center_[1] +
	   modelview_matrix_[10]*center_[2] + 
	   modelview_matrix_[14] );
  
  makeCurrent();
  glLoadIdentity();
  glTranslatef(t[0], t[1], t[2]);
  glRotated( _angle, _axis[0], _axis[1], _axis[2]);
  glTranslatef(-t[0], -t[1], -t[2]); 
  glMultMatrixd(modelview_matrix_);
  glGetDoublev(GL_MODELVIEW_MATRIX, modelview_matrix_);
}


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


bool
QGLViewerWidget::map_to_sphere( const QPoint& _v2D, Vec3f& _v3D )
{
  if ( (_v2D.x() >= 0) && (_v2D.x() <= width()) &&
       (_v2D.y() >= 0) && (_v2D.y() <= height()) ) 
  {
    double x  = (double)(_v2D.x() - 0.5*width())  / (double)width();
    double y  = (double)(0.5*height() - _v2D.y()) / (double)height();
    double sinx         = sin(M_PI * x * 0.5);
    double siny         = sin(M_PI * y * 0.5);
    double sinx2siny2   = sinx * sinx + siny * siny;
    
    _v3D[0] = sinx;
    _v3D[1] = siny;
    _v3D[2] = sinx2siny2 < 1.0 ? sqrt(1.0 - sinx2siny2) : 0.0;
    
    return true;
  }
  else return false;
}


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


void
QGLViewerWidget::update_projection_matrix()
{
  makeCurrent();
  glMatrixMode( GL_PROJECTION );
  glLoadIdentity();
  gluPerspective(45.0, (GLfloat) width() / (GLfloat) height(),
		 0.01*radius_, 100.0*radius_);
  glGetDoublev( GL_PROJECTION_MATRIX, projection_matrix_);
  glMatrixMode( GL_MODELVIEW );
}


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


void
QGLViewerWidget::view_all()
{  
  translate( Vec3f( -(modelview_matrix_[0]*center_[0] + 
		      modelview_matrix_[4]*center_[1] +
		      modelview_matrix_[8]*center_[2] + 
		      modelview_matrix_[12]),
		    -(modelview_matrix_[1]*center_[0] + 
		      modelview_matrix_[5]*center_[1] +
		      modelview_matrix_[9]*center_[2] + 
		      modelview_matrix_[13]),
		    -(modelview_matrix_[2]*center_[0] + 
		      modelview_matrix_[6]*center_[1] +
		      modelview_matrix_[10]*center_[2] + 
		      modelview_matrix_[14] +
		      3.0*radius_) ) );
}


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


void
QGLViewerWidget::set_scene_pos( const Vec3f& _cog, float _radius )
{
  center_ = _cog;
  radius_ = _radius;
  glFogf( GL_FOG_START,      1.5*_radius );
  glFogf( GL_FOG_END,        3.0*_radius );

  update_projection_matrix();
  view_all();
}


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


void 
QGLViewerWidget::add_draw_mode(const std::string& _s)
{
  ++n_draw_modes_;

  // insert in popup menu
  popup_menu_->insertItem(_s.c_str(), n_draw_modes_);

  // store draw mode
  draw_mode_names_.push_back(_s);
}


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


void 
QGLViewerWidget::del_draw_mode(const std::string& _s)
{
  std::vector<std::string>::iterator it =
    std::find(draw_mode_names_.begin(), draw_mode_names_.end(), _s );
  
#if _DEBUG
  assert( it != draw_mode_names_.end() );
#else
  if ( it == draw_mode_names_.end() )
    return;
#endif

  for(int idx=0; size_t(idx) < popup_menu_->count(); ++idx)
  {
    int id = popup_menu_->idAt(idx);
    if (id!=-1 && popup_menu_->text(id) == _s.c_str())
    {
      popup_menu_->removeItemAt(idx);
      draw_mode_names_.erase(it, it+1);
      break;
    }
  }
}


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


void
QGLViewerWidget::slotPopupMenu(int _id)
{
  // un-check all entries
  for (size_t i=1; i <= n_draw_modes_; ++i)
    popup_menu_->setItemChecked(i, false);

  // save draw mode
  draw_mode_ = _id;

  // check selected draw mode
  popup_menu_->setItemChecked(_id, true);
}


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


double 
QGLViewerWidget::performance()
{
  setCursor( waitCursor );

  double fps(0.0);

  makeCurrent();
  glMatrixMode(GL_MODELVIEW);
  glPushMatrix();

  OpenMesh::Utils::Timer timer;

  unsigned int  frames = 60;
  const float   angle  = 360.0/(float)frames;
  unsigned int  i;
  Vec3f         axis;

  glFinish();

  timer.start();
  for (i=0, axis=Vec3f(1,0,0); i<frames; ++i)
  { rotate(axis, angle); paintGL(); swapBuffers(); }
  timer.stop();

  qApp->processEvents();

  timer.cont();
  for (i=0, axis=Vec3f(0,1,0); i<frames; ++i)
  { rotate(axis, angle); paintGL(); swapBuffers(); }
  timer.stop();

  qApp->processEvents();

  timer.cont();
  for (i=0, axis=Vec3f(0,0,1); i<frames; ++i)
  { rotate(axis, angle); paintGL(); swapBuffers(); }
  timer.stop();

  glFinish();
  timer.stop();

  glPopMatrix();
  updateGL();

  fps = ( (3.0 * frames) / timer.seconds() );

  setCursor( pointingHandCursor );

  return fps;
}


void
QGLViewerWidget::slotSnapshot( void )
{  
  QImage image;
  size_t w(width()), h(height());
  GLenum buffer( GL_BACK );

  try
  {
    image = QImage(w, h, 32);  // 32-bit image
  
    std::vector<GLubyte> fbuffer(3*w*h);

    qApp->processEvents();
    makeCurrent();
    updateGL();
    glFinish();
    
    glReadBuffer( buffer );
    glPixelStorei(GL_PACK_ALIGNMENT, 1);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    paintGL();
    glReadPixels(0, 0, w, h, GL_RGB, GL_UNSIGNED_BYTE, &fbuffer[0] );
    
    unsigned int x,y,offset;
    
    for (y=0; y<h; ++y) {
      for (x=0; x<w; ++x) {
        offset = 3*(y*w + x);
        image.setPixel(x, h-y-1, qRgb(fbuffer[offset],
                                      fbuffer[offset+1],
                                      fbuffer[offset+2]));
      }
    }
    
    
    QString name = "snapshot-";
#if defined(_MSC_VER)
    {
      std::stringstream s;
      QDateTime         dt = QDateTime::currentDateTime();
      s << dt.date().year() 
        << std::setw(2) << std::setfill('0') << dt.date().month() 
        << std::setw(2) << std::setfill('0') << dt.date().day()
        << std::setw(2) << std::setfill('0') << dt.time().hour()
        << std::setw(2) << std::setfill('0') << dt.time().minute()
        << std::setw(2) << std::setfill('0') << dt.time().second();
      name += QString(s.str().c_str());
    }
#else
    name += QDateTime::currentDateTime().toString( "yyMMddhhmmss" );
#endif
    name += ".png";

    image.save( name, "PNG");
  }
  catch( std::bad_alloc& )
  {
    qWarning("Mem Alloc Error");
  }
  
}



//=============================================================================