vdr.cpp

来自「提取各种NEMA0183格式数据的类编程。」· C++ 代码 · 共 136 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: vdr.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

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

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

void VDR::Empty( void )
{
   DegreesTrue     = 0.0;
   DegreesMagnetic = 0.0;
   Knots           = 0.0;
}

BOOL VDR::Parse( const SENTENCE& sentence )
{
   /*
   ** VDR - Set and Drift
   **
   **        1   2 3   4 5   6 7
   **        |   | |   | |   | |
   ** $--VDR,x.x,T,x.x,M,x.x,N*hh<CR><LF>
   **
   ** Field Number: 
   **  1) Degress True
   **  2) T = True
   **  3) Degrees Magnetic
   **  4) M = Magnetic
   **  5) Knots (speed of current)
   **  6) N = Knots
   **  7) Checksum
   */

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

   const NMEA0183_BOOLEAN checksum_is_bad = sentence.IsChecksumBad();

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

   DegreesTrue     = sentence.Double( 1 );
   DegreesMagnetic = sentence.Double( 3 );
   Knots           = sentence.Double( 5 );

   return( TRUE );
}

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

   sentence += DegreesTrue;
   sentence += TEXT( "T" );
   sentence += DegreesMagnetic;
   sentence += TEXT( "M" );
   sentence += Knots;
   sentence += TEXT( "N" );

   sentence.Finish();

   return( TRUE );
}

const VDR& VDR::operator = ( const VDR& source )
{
   DegreesTrue     = source.DegreesTrue;
   DegreesMagnetic = source.DegreesMagnetic;
   Knots           = source.Knots;

   return( *this );
}