Truxton location get longitude

This retrieves longitude portion of the location. This corresponds to the [Longitude] column of the [Location] table.

Syntax

double truxton_location_get_longitude( uint64_t location_handle );

Parameters

location_handle

This handle comes from calling truxton_location_create() or truxton_child_file_create_location()

Return value

The longitude of the location in decimal degrees using the WGS84 ellipsoid.

Sample

void dump_location( uint64_t location_handle )
{
   double value = 0;
   uint64_t ticks = 0;
   char guid_string[ 40 ];
   char label[ 256 ];

   truxton_location_get_label( location_handle, label, sizeof( label ) );
   printf( "%s\n", label );

   truxton_location_get_file_id( location_handle, guid_string, sizeof( guid_string ) );
   printf( "File ID: %s\n", guid_string );

   truxton_location_get_media_id( location_handle, guid_string, sizeof( guid_string ) );
   printf( "Media ID: %s\n", guid_string );

   value = truxton_location_get_latitude( location_handle );
   printf( "Latitude: %lf\n", value );

   value = truxton_location_get_longitude( location_handle );
   printf( "Longitude: %lf\n", value );

   value = truxton_location_get_altitude( location_handle );
   printf( "Altitude: %lf meters\n", value );

   ticks = truxton_location_get_type( location_handle );
   printf( "Type: %" PRIu64 "\n", ticks );

   ticks = truxton_location_get_when( location_handle );
   printf( "Ticks: %" PRIu64 "\n", ticks );
}

The PRIu64 in the sample code above is a standard way of formatting a 64-bit unsigned integer in C. Over the years, different compilers on different operating systems used different format specifiers for things, these PRI macros, along with some tricky string concatenation the compilers perform for you, allow you to maintain a single code base without a bunch of macro magic.