//! Modifies the screen update mode.
  //!
  //! TOU_ASAP - as soon as possible
  //! TOU_WAIT - on demand (with the Update function)
  //! Note : Dynamic Operations and Update Mode
  //! Use SetUpdateMode to control when changes to
  //! the display are made.   Use one of the   following
  //! functions to update one or more views:
  //! - Update all views of the viewer: Graphic3d_StructureManager::Update()
  //! - Update one view of the viewer:  Graphic3d_View::Update()
  //! Use one of the following functions to update the entire display:
  //! - Redraw all structures in all views: Graphic3d_StructureManager::Redraw()
  //! - Redraw all structures in one view:  Graphic3d_View::Redraw()
  void SetUpdateMode (const Aspect_TypeOfUpdate theType) { myUpdateMode = theType; }