tigerpolygon.cpp

支持各种栅格图像和矢量图像读取的库

    if( bUsingRTS ) {
      AddFieldDefns(psRTSInfo, poFeatureDefn);
    }
}

/************************************************************************/
/*                           ~TigerPolygon()                            */
/************************************************************************/

TigerPolygon::~TigerPolygon()

{
    if( fpRTS != NULL )
        VSIFClose( fpRTS );
}

/************************************************************************/
/*                             SetModule()                              */
/************************************************************************/

int TigerPolygon::SetModule( const char * pszModule )

{
    if( !OpenFile( pszModule, "A" ) )
        return FALSE;

    EstablishFeatureCount();
    
/* -------------------------------------------------------------------- */
/*      Open the RTS file                                               */
/* -------------------------------------------------------------------- */
    if( bUsingRTS )
    {
        if( fpRTS != NULL )
        {
            VSIFClose( fpRTS );
            fpRTS = NULL;
        }

        if( pszModule )
        {
            char        *pszFilename;
        
            pszFilename = poDS->BuildFilename( pszModule, "S" );

            fpRTS = VSIFOpen( pszFilename, "rb" );

            CPLFree( pszFilename );

            nRTSRecLen = EstablishRecordLength( fpRTS );
        }
    }
    
    return TRUE;
}

/************************************************************************/
/*                             GetFeature()                             */
/************************************************************************/

OGRFeature *TigerPolygon::GetFeature( int nRecordId )

{
  char        achRecord[OGR_TIGER_RECBUF_LEN];

    if( nRecordId < 0 || nRecordId >= nFeatures )
    {
        CPLError( CE_Failure, CPLE_FileIO,
                  "Request for out-of-range feature %d of %sA",
                  nRecordId, pszModule );
        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Read the raw record data from the file.                         */
/* -------------------------------------------------------------------- */
    if( fpPrimary == NULL )
        return NULL;

    if( VSIFSeek( fpPrimary, nRecordId * nRecordLength, SEEK_SET ) != 0 )
    {
        CPLError( CE_Failure, CPLE_FileIO,
                  "Failed to seek to %d of %sA",
                  nRecordId * nRecordLength, pszModule );
        return NULL;
    }

    if( VSIFRead( achRecord, nRecordLength, 1, fpPrimary ) != 1 )
    {
        CPLError( CE_Failure, CPLE_FileIO,
                  "Failed to read record %d of %sA",
                  nRecordId, pszModule );
        return NULL;
    }

    /* -------------------------------------------------------------------- */
    /*      Set fields.                                                     */
    /* -------------------------------------------------------------------- */

    OGRFeature  *poFeature = new OGRFeature( poFeatureDefn );

    SetFields( psRTAInfo, poFeature, achRecord );

    /* -------------------------------------------------------------------- */
    /*      Read RTS record, and apply fields.                              */
    /* -------------------------------------------------------------------- */

    if( fpRTS != NULL )
    {
        char    achRTSRec[OGR_TIGER_RECBUF_LEN];

        if( VSIFSeek( fpRTS, nRecordId * nRTSRecLen, SEEK_SET ) != 0 )
        {
            CPLError( CE_Failure, CPLE_FileIO,
                      "Failed to seek to %d of %sS",
                      nRecordId * nRTSRecLen, pszModule );
            return NULL;
        }

        if( VSIFRead( achRTSRec, psRTSInfo->nRecordLength, 1, fpRTS ) != 1 )
        {
            CPLError( CE_Failure, CPLE_FileIO,
                      "Failed to read record %d of %sS",
                      nRecordId, pszModule );
            return NULL;
        }

        SetFields( psRTSInfo, poFeature, achRTSRec );

    }
    
    return poFeature;
}

/************************************************************************/
/*                           SetWriteModule()                           */
/************************************************************************/

int TigerPolygon::SetWriteModule( const char *pszFileCode, int nRecLen, 
                                  OGRFeature *poFeature )

{
    int bSuccess;

    bSuccess = TigerFileBase::SetWriteModule( pszFileCode, nRecLen, poFeature);
    if( !bSuccess )
        return bSuccess;

/* -------------------------------------------------------------------- */
/*      Open the RT3 file                                               */
/* -------------------------------------------------------------------- */
    if( bUsingRTS )
    {
        if( fpRTS != NULL )
        {
            VSIFClose( fpRTS );
            fpRTS = NULL;
        }

        if( pszModule )
        {
            char        *pszFilename;
        
            pszFilename = poDS->BuildFilename( pszModule, "S" );

            fpRTS = VSIFOpen( pszFilename, "ab" );

            CPLFree( pszFilename );
        }
    }
    
    return TRUE;
}

/************************************************************************/
/*                           CreateFeature()                            */
/************************************************************************/

OGRErr TigerPolygon::CreateFeature( OGRFeature *poFeature )

{
    char        szRecord[OGR_TIGER_RECBUF_LEN];

/* -------------------------------------------------------------------- */
/*      Write basic data record ("RTA")                                 */
/* -------------------------------------------------------------------- */

    if( !SetWriteModule( "A", psRTAInfo->nRecordLength+2, poFeature ) )
        return OGRERR_FAILURE;

    memset( szRecord, ' ', psRTAInfo->nRecordLength );

    WriteFields( psRTAInfo, poFeature, szRecord );
    WriteRecord( szRecord, psRTAInfo->nRecordLength, "A" );

/* -------------------------------------------------------------------- */
/*      Prepare S record.                                               */
/* -------------------------------------------------------------------- */

    memset( szRecord, ' ', psRTSInfo->nRecordLength );

    WriteFields( psRTSInfo, poFeature, szRecord );
    WriteRecord( szRecord, psRTSInfo->nRecordLength, "S", fpRTS );


    return OGRERR_NONE;
}