Method GetValueImpl

tools/topography_generator/generator.cpp:96–123

private:
  Altitude GetValueImpl(ms::LatLon pos)
  {
    if (m_preferredTile != nullptr)
    {
      using mercator::kPointEqualityEps;

      // Each SRTM tile overlaps the top row in the bottom tile and the right row in the left tile.
      // Try to prevent loading a new tile if the position can be found in the loaded one.
      auto const latDist = pos.m_lat - m_leftBottomOfPreferredTile.m_lat;
      auto const lonDist = pos.m_lon - m_leftBottomOfPreferredTile.m_lon;
      if (latDist > -kPointEqualityEps && latDist < 1.0 + kPointEqualityEps && lonDist > -kPointEqualityEps &&
          lonDist < 1.0 + kPointEqualityEps)
      {
        if (latDist < 0.0)
          pos.m_lat += kPointEqualityEps;
        else if (latDist >= 1.0)
          pos.m_lat -= kPointEqualityEps;
        if (lonDist < 0.0)
          pos.m_lon += kPointEqualityEps;
        else if (lonDist >= 1.0)
          pos.m_lon -= kPointEqualityEps;

        return m_preferredTile->GetAltitude(pos);
      }
    }

    return m_srtmManager.GetAltitude(pos);
  }

  Altitude GetMedianValue(ms::LatLon const & pos)
  {