navfilterex-pseudo-inherit.cpp

Pseudo-code example of using inheritance for the filter data for storing the navigation messages processed by the filter.

//==============================================================================
//
//  This file is part of GNSSTk, the ARL:UT GNSS Toolkit.
//
//  The GNSSTk 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 3.0 of the License, or
//  any later version.
//
//  The GNSSTk is distributed in the hope that it will be useful,
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//  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 Lesser General Public
//  License along with GNSSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//
//  This software was developed by Applied Research Laboratories at the
//  University of Texas at Austin.
//  Copyright 2004-2022, The Board of Regents of The University of Texas System
//
//==============================================================================
 
//==============================================================================
//
//  This software was developed by Applied Research Laboratories at the
//  University of Texas at Austin, under contract to an agency or agencies
//  within the U.S. Department of Defense. The U.S. Government retains all
//  rights to use, duplicate, distribute, disclose, or release this software.
//
//  Pursuant to DoD Directive 523024
//
//  DISTRIBUTION STATEMENT A: This software has been approved for public
//                            release, distribution is unlimited.
//
//==============================================================================
 
class NavSubframe
{
public:
   std::vector<uint32_t> subframe;
};
 
class MyNavFilterData : public gnsstk::LNavFilterData
{
public:
   NavSubframe appData;
};
 
MyNavFilterData* readNav()
{
   if (!strm)
      return NULL;
   MyNavFilterData *rv = new MyNavFilterData();
   strm >> rv->appData;
   retun rv;
}
 
void filterEX()
{
      // Filter manager, where the work is done
   gnsstk::NavFilterMgr mgr;
      // Individual filters being applied
   gnsstk::LNavCookFilter filtCook;
   gnsstk::LNavCrossSourceFilter filtVote;
   gnsstk::NavFilter::NavMsgList::const_iterator nmli;
 
      // Tell the manager what filters to use
   mgr.addFilter(&filtCook);
   mgr.addFilter(&filtVote);
 
   while (strm)
   {
      MyNavFilterData *fd = readNav();
 
         // validate the subframe
      gnsstk::NavFilter::NavMsgList l = mgr.validate(fd);
 
         // process the results
      for (nmli = l.begin(); nmli != l.end(); nmli++)
      {
         MyNavFilterData *ofd = dynamic_cast<MyNavFilterData*>(*nmli);
            // do something with fd (nav message that passed the filters)
 
            // Then free the memory.  Note that this would also free
            // the application's data, so you may want to delay this
            // depending on what you're trying to do.
         delete ofd;
      }
   }
 
      // Finalize the filters.  Probably not necessary when using only
      // depth 1 filters, but good practice in any case.
   gnsstk::NavFilter::NavMsgList l = mgr.finalize();
 
      // process the results
   for (nmli = l.begin(); nmli != l.end(); nmli++)
   {
      MyNavFilterData *ofd = dynamic_cast<MyNavFilterData*>(*nmli);
         // do something with fd (nav message that passed the filters)
 
         // Then free the memory.  Note that this would also free
         // the application's data, so you may want to delay this
         // depending on what you're trying to do.
      delete ofd;
   }
}