xte.cpp

来自「提取各种NEMA0183格式数据的类编程。」· C++ 代码 · 共 160 行

/*
** Author: Samuel R. Blackburn
** Internet: [e-mail]
**
** Copyright, 1996-2005, Samuel R. Blackburn
**
** "You can get credit for something or get it done, but not both."
** Dr. Richard Garwin
**
** BSD License follows.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** Redistributions of source code must retain the above copyright notice,
** this list of conditions and the following disclaimer. Redistributions
** in binary form must reproduce the above copyright notice, this list
** of conditions and the following disclaimer in the documentation and/or
** other materials provided with the distribution. Neither the name of
** the WFC nor the names of its contributors may be used to endorse or
** promote products derived from this software without specific prior
** written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**
** $Workfile: xte.cpp $
** $Revision: 4 $
** $Modtime: 10/10/98 2:39p $
*/

#include "nmea0183.h"
#pragma hdrstop

#if defined( _DEBUG ) && defined( _INC_CRTDBG )
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#define new DEBUG_NEW
#endif // _DEBUG

XTE::XTE()
{
   Mnemonic = TEXT( "XTE" );
   Empty();
}

XTE::~XTE()
{
   Mnemonic.Empty();
   Empty();
}

void XTE::Empty( void )
{
   CrossTrackErrorMagnitude = 0.0;
   DirectionToSteer         = LR_Unknown;
   CrossTrackUnits.Empty();
   FAAMode                  = FAAModeUnknown;
}

BOOL XTE::Parse( const SENTENCE& sentence )
{
   CString field_data;

   /*
   ** XTE - Cross-Track Error, Measured
   **
   **        1 2 3   4 5  6
   **        | | |   | |  |
   ** $--XTE,A,A,x.x,a,N,*hh<CR><LF>
   **
   **  1) Status
   **     V = LORAN-C Blink or SNR warning
   **     V = general warning flag or other navigation systems when a reliable
   **         fix is not available
   **  2) Status
   **     V = Loran-C Cycle Lock warning flag
   **     A = OK or not used
   **  3) Cross Track Error Magnitude
   **  4) Direction to steer, L or R
   **  5) Cross Track Units, N = Nautical Miles
   **  6) Checksum
   */

   /*
   ** First we check the checksum...
   */

   const NMEA0183_BOOLEAN checksum_is_bad = sentence.IsChecksumBad();

   if ( checksum_is_bad == True )
   {
      InvalidChecksum();
      return( FALSE );
   } 

   /*
   ** Line has already been checked for checksum validity
   */

   IsLoranBlinkOK           = sentence.Boolean( 1 );
   IsLoranCCycleLockOK      = sentence.Boolean( 2 );
   CrossTrackErrorMagnitude = sentence.Double( 3 );
   DirectionToSteer         = sentence.LeftOrRight( 4 );
   CrossTrackUnits          = sentence.Field( 5 );

   const int checksum_field_number = sentence.ChecksumFieldNumber();

   if ( checksum_field_number == 7 )
   {
      FAAMode = sentence.FAAMode( 6 );
   }
   else
   {
      FAAMode = FAAModeUnknown;
   }

   return( TRUE );
}

BOOL XTE::Write( SENTENCE& sentence )
{
   /*
   ** Let the parent do its thing
   */
   
   RESPONSE::Write( sentence );

   sentence += IsLoranBlinkOK;
   sentence += IsLoranCCycleLockOK;
   sentence += CrossTrackErrorMagnitude;
   sentence += DirectionToSteer;
   sentence += CrossTrackUnits;

   sentence.Finish();

   return( TRUE );
}

const XTE& XTE::operator = ( const XTE& source )
{
   IsLoranBlinkOK           = source.IsLoranBlinkOK;
   IsLoranCCycleLockOK      = source.IsLoranCCycleLockOK;
   CrossTrackErrorMagnitude = source.CrossTrackErrorMagnitude;
   DirectionToSteer         = source.DirectionToSteer;
   CrossTrackUnits          = source.CrossTrackUnits;

   return( *this );
}