ttm.cpp

提取各种NEMA0183格式数据的类编程。

/*
** 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: ttm.cpp $
** $Revision: 4 $
** $Modtime: 10/10/98 2:38p $
*/

#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

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

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

void TTM::Empty( void )
{
   TargetNumber                            = 0;
   TargetDistance                          = 0.0;
   BearingFromOwnShip                      = 0.0;
   BearingUnits.Empty();
   TargetSpeed                             = 0.0;
   TargetCourse                            = 0.0;
   TargetCourseUnits.Empty();
   DistanceOfClosestPointOfApproach        = 0.0;
   NumberOfMinutesToClosestPointOfApproach = 0.0;
   Increasing.Empty();
   TargetName.Empty();
   TargetStatus                            = TargetUnknown;
}

BOOL TTM::Parse( const SENTENCE& sentence )
{
   /*
   ** TTM - Tracked Target Message
   **
   **                                         11     13
   **        1  2   3   4 5   6   7 8   9   10|    12| 14
   **        |  |   |   | |   |   | |   |   | |    | | |
   ** $--TTM,xx,x.x,x.x,a,x.x,x.x,a,x.x,x.x,a,c--c,a,a*hh<CR><LF>
   **
   **  1) Target Number
   **  2) Target Distance
   **  3) Bearing from own ship
   **  4) Bearing Units
   **  5) Target speed
   **  6) Target Course
   **  7) Course Units
   **  8) Distance of closest-point-of-approach
   **  9) Time until closest-point-of-approach "-" means increasing
   ** 10) "-" means increasing
   ** 11) Target name
   ** 12) Target Status
   ** 13) Reference Target
   ** 14) Checksum
   */

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

   const NMEA0183_BOOLEAN checksum_is_bad = sentence.IsChecksumBad();

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

   TargetNumber                            = sentence.Integer( 1 );
   TargetDistance                          = sentence.Double( 2 );
   BearingFromOwnShip                      = sentence.Double( 3 );
   BearingUnits                            = sentence.Field( 4 );
   TargetSpeed                             = sentence.Double( 5 );
   TargetCourse                            = sentence.Double( 6 );
   TargetCourseUnits                       = sentence.Field( 7 );
   DistanceOfClosestPointOfApproach        = sentence.Double( 8 );
   NumberOfMinutesToClosestPointOfApproach = sentence.Double( 9 );
   Increasing                              = sentence.Field( 10 );
   TargetName                              = sentence.Field( 11 );
   
   CString field_data = sentence.Field( 12 );

   if ( field_data == TEXT( "L" ) )
   {
      TargetStatus = TargetLost;
   }
   else if ( field_data == TEXT( "Q" ) )
   {
      TargetStatus = TargetQuery;
   }
   else if ( field_data == TEXT( "T" ) )
   {
      TargetStatus = TargetTracking;
   }
   else
   {
      TargetStatus = TargetUnknown;
   }

   ReferenceTarget = sentence.Field( 13 );

   return( TRUE );
}

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

   sentence += TargetNumber;
   sentence += TargetDistance;
   sentence += BearingFromOwnShip;
   sentence += BearingUnits;
   sentence += TargetSpeed;
   sentence += TargetCourse;
   sentence += TargetCourseUnits;
   sentence += DistanceOfClosestPointOfApproach;
   sentence += NumberOfMinutesToClosestPointOfApproach;
   sentence += Increasing;
   sentence += TargetName;
   
   switch( TargetStatus )
   {
      case TargetLost:

         sentence += TEXT( "L" );
         break;

      case TargetQuery:

         sentence += TEXT( "Q" );
         break;

      case TargetTracking:

         sentence += TEXT( "T" );
         break;

      default:

         sentence += TEXT( "" );
         break;
   }

   sentence += ReferenceTarget;

   sentence.Finish();

   return( TRUE );
}

const TTM& TTM::operator = ( const TTM& source )
{
   TargetNumber                            = source.TargetNumber;
   TargetDistance                          = source.TargetDistance;
   BearingFromOwnShip                      = source.BearingFromOwnShip;
   BearingUnits                            = source.BearingUnits;
   TargetSpeed                             = source.TargetSpeed;
   TargetCourse                            = source.TargetCourse;
   TargetCourseUnits                       = source.TargetCourseUnits;
   DistanceOfClosestPointOfApproach        = source.DistanceOfClosestPointOfApproach;
   NumberOfMinutesToClosestPointOfApproach = source.NumberOfMinutesToClosestPointOfApproach;
   Increasing                              = source.Increasing;
   TargetName                              = source.TargetName;
   TargetStatus                            = source.TargetStatus;

   return( *this );
}