LAT.CPP

/*
Author: Samuel R. Blackburn
Internet: wfc@pobox.com

"You can get credit for something or get it done, but not both."
Dr. Richard Garwin

The MIT License (MIT)

Copyright (c) 1996-2019 Sam Blackburn

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

// SPDX-License-Identifier: MIT

#include "nmea0183.h"
#pragma hdrstop

void LATITUDE::Empty( void ) noexcept
{
   Latitude = 0.0;
   Northing = NORTHSOUTH::NS_Unknown;
}

bool LATITUDE::IsDataValid( void ) const noexcept
{
   if ( Northing not_eq NORTHSOUTH::North and Northing not_eq NORTHSOUTH::South )
   {
      return( false );
   }

   return( true );
}

void LATITUDE::Parse( int position_field_number, int north_or_south_field_number, SENTENCE const& sentence ) noexcept
{
   // Thanks go to Eric Parsonage (ericpa@mpx.com.au) for finding a nasty
   // little bug that used to live here.

   auto const position{ sentence.Double(position_field_number) };
   auto north_or_south{ sentence.Field(north_or_south_field_number) };

   Set( position, north_or_south );
}

void LATITUDE::Set( double position, std::string_view north_or_south ) noexcept
{
   Latitude   = position;
   Coordinate = position;

   if (north_or_south.empty() == true)
   {
       Northing = NORTHSOUTH::NS_Unknown;
       return;
   }

   if ( north_or_south[ 0 ] == 'N' )
   {
      Northing = NORTHSOUTH::North;
   }
   else if ( north_or_south[ 0 ] == 'S' )
   {
      Northing = NORTHSOUTH::South;
   }
   else
   {
      Northing = NORTHSOUTH::NS_Unknown;
   }
}

void LATITUDE::Write( SENTENCE& sentence ) const noexcept
{
   char temp_string[ 80 ];

   auto const number_of_characters{ ::sprintf(temp_string, "%07.2f", Latitude) };
   sentence += std::string_view( temp_string, number_of_characters);

   if ( Northing == NORTHSOUTH::North )
   {
      sentence += STRING_VIEW("N");
   }
   else if ( Northing == NORTHSOUTH::South )
   {
      sentence += STRING_VIEW("S");
   }
   else
   {
      /*
      ** Thanks to Jan-Erik Eriksson (Jan-Erik.Eriksson@st.se) for
      ** finding and fixing a bug here
      */

      sentence += STRING_VIEW("");
   }
}

LATITUDE const& LATITUDE::operator = ( LATITUDE const& source ) noexcept
{
   Latitude = source.Latitude;
   Northing = source.Northing;

   return( *this );
}

// COORDINATE stuff

// Coordinates are in the format dddmm.ddd
// For example, 76 degrees 46.887 minutes would be 7646.887

double COORDINATE::GetDecimalDegrees( void ) const noexcept
{
   int degrees{ static_cast<int>(::floor(Coordinate)) };
   int minutes{ degrees % 100 };

   double throw_away{ 0.0 };

   auto fractional_minutes{ ::modf(Coordinate, &throw_away) };

   degrees -= minutes;
   degrees /= 100;

   auto return_value{ static_cast<double>(degrees) };
   return_value += static_cast<double>( static_cast<double>(minutes) / static_cast<double>(60.0) );
   return_value += static_cast<double>( static_cast<double>(fractional_minutes) / static_cast<double>(60.0) );

   return( return_value );
}

double COORDINATE::GetDecimalMinutes(void) const noexcept
{
   int degrees{ static_cast<int>(::floor(Coordinate)) };
   int minutes{ degrees % 100 };

   double throw_away{ 0.0 };
   auto fractional_minutes{ ::modf(Coordinate, &throw_away) };
   double return_value{ static_cast<double>(minutes) };
   return_value += fractional_minutes;

   return( return_value );
}

double COORDINATE::GetDecimalSeconds( void ) const noexcept
{
   auto minutes{ GetDecimalMinutes() };
   double throw_away{ 0.0 };
   auto fractional_minutes{ ::modf(minutes, &throw_away) };
   auto return_value{ static_cast<double>(static_cast<double>(fractional_minutes) * static_cast<double>(60.0)) };

   return( return_value );
}