tigercompletechain.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

      psRT1Info = &rt1_2002_info;
      bUsingRT3 = FALSE;
    } else {
      psRT1Info = &rt1_info;
      bUsingRT3 = TRUE;
    }

    psRT2Info = &rt2_info;

    nRT1RecOffset = 0;

    if (poDS->GetVersion() >= TIGER_2000_Redistricting) {
      psRT3Info = &rt3_2000_Redistricting_info;
    } else {
      psRT3Info = &rt3_info;
    }

    fpRT3 = NULL;

    panShapeRecordId = NULL;
    fpShape = NULL;
    
    /* -------------------------------------------------------------------- */
    /*      Fields from type 1 record.                                      */
    /* -------------------------------------------------------------------- */

    AddFieldDefns( psRT1Info, poFeatureDefn );

    /* -------------------------------------------------------------------- */
    /*      Fields from type 3 record.  Eventually we should verify that    */
    /*      a .RT3 file is available before adding these fields.            */
    /* -------------------------------------------------------------------- */
    if( bUsingRT3 ) {
      AddFieldDefns( psRT3Info, poFeatureDefn );
    }
}

/************************************************************************/
/*                        ~TigerCompleteChain()                         */
/************************************************************************/

TigerCompleteChain::~TigerCompleteChain()

{
    CPLFree( panShapeRecordId );

    if( fpRT3 != NULL )
        VSIFClose( fpRT3 );

    if( fpShape != NULL )
        VSIFClose( fpShape );
}

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

int TigerCompleteChain::SetModule( const char * pszModule )

{
    if( !OpenFile( pszModule, "1" ) )
        return FALSE;

    EstablishFeatureCount();

/* -------------------------------------------------------------------- */
/*      Is this a copyright record inserted at the beginning of the     */
/*      RT1 file by the folks at GDT?  If so, setup to ignore the       */
/*      first record.                                                   */
/* -------------------------------------------------------------------- */
    nRT1RecOffset = 0;
    if( pszModule )
    {
        char achHeader[10];
        
        VSIFSeek( fpPrimary, 0, SEEK_SET );
        VSIFRead( achHeader, sizeof(achHeader), 1, fpPrimary );
        
        if( EQUALN(achHeader,"Copyright",8) )
        {
            nRT1RecOffset = 1;
            nFeatures--;
        }
    }
        
/* -------------------------------------------------------------------- */
/*      Open the RT3 file                                               */
/* -------------------------------------------------------------------- */
    if( bUsingRT3 )
    {
        if( fpRT3 != NULL )
        {
            VSIFClose( fpRT3 );
            fpRT3 = NULL;
        }

        if( pszModule )
        {
            char        *pszFilename;
        
            pszFilename = poDS->BuildFilename( pszModule, "3" );

            fpRT3 = VSIFOpen( pszFilename, "rb" );

            CPLFree( pszFilename );
        }
    }
    
/* -------------------------------------------------------------------- */
/*      Close the shape point file, if open and free the list of        */
/*      record ids.                                                     */
/* -------------------------------------------------------------------- */
    if( fpShape != NULL )
    {
        VSIFClose( fpShape );
        fpShape = NULL;
    }
    
    CPLFree( panShapeRecordId );
    panShapeRecordId = NULL;

/* -------------------------------------------------------------------- */
/*      Try to open the RT2 file corresponding to this RT1 file.        */
/* -------------------------------------------------------------------- */
    if( pszModule != NULL )
    {
        char    *pszFilename;

        pszFilename = poDS->BuildFilename( pszModule, "2" );

        fpShape = VSIFOpen( pszFilename, "rb" );
        
        if( fpShape == NULL )
        {
            if( nRT1RecOffset == 0 )
                CPLError( CE_Warning, CPLE_OpenFailed,
                          "Failed to open %s, intermediate shape arcs will not be available.\n",
                          pszFilename );
        }
        else
            panShapeRecordId = (int *)CPLCalloc(sizeof(int),GetFeatureCount());
        
        CPLFree( pszFilename );
    }

    return TRUE;
}

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

OGRFeature *TigerCompleteChain::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 %s1",
                  nRecordId, pszModule );
        return NULL;
    }

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

    if( VSIFSeek( fpPrimary, (nRecordId+nRT1RecOffset) * nRecordLength, 
                  SEEK_SET ) != 0 )
    {
        CPLError( CE_Failure, CPLE_FileIO,
                  "Failed to seek to %d of %s1",
                  nRecordId * nRecordLength, pszModule );
        return NULL;
    }

    if( VSIFRead( achRecord, psRT1Info->nRecordLength, 1, fpPrimary ) != 1 )
    {
        CPLError( CE_Failure, CPLE_FileIO,
                  "Failed to read %d bytes of record %d of %s1 at offset %d",
                  psRT1Info->nRecordLength, nRecordId, pszModule,
                  (nRecordId+nRT1RecOffset) * nRecordLength );
        return NULL;
    }

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

    OGRFeature  *poFeature = new OGRFeature( poFeatureDefn );

    SetFields( psRT1Info, poFeature, achRecord );

    /* -------------------------------------------------------------------- */
    /*      Read RT3 record, and apply fields.                              */
    /* -------------------------------------------------------------------- */

    if( fpRT3 != NULL )
    {
        char    achRT3Rec[OGR_TIGER_RECBUF_LEN];
        int     nRT3RecLen = psRT3Info->nRecordLength + nRecordLength - psRT1Info->nRecordLength;

        if( VSIFSeek( fpRT3, nRecordId * nRT3RecLen, SEEK_SET ) != 0 )
        {
            CPLError( CE_Failure, CPLE_FileIO,
                      "Failed to seek to %d of %s3",
                      nRecordId * nRT3RecLen, pszModule );
            return NULL;
        }

        if( VSIFRead( achRT3Rec, psRT3Info->nRecordLength, 1, fpRT3 ) != 1 )
        {
            CPLError( CE_Failure, CPLE_FileIO,
                      "Failed to read record %d of %s3",
                      nRecordId, pszModule );
            return NULL;
        }

        SetFields( psRT3Info, poFeature, achRT3Rec );

    }

/* -------------------------------------------------------------------- */
/*      Set geometry                                                    */
/* -------------------------------------------------------------------- */
    OGRLineString       *poLine = new OGRLineString();

    poLine->setPoint(0,
                     atoi(GetField(achRecord, 191, 200)) / 1000000.0,
                     atoi(GetField(achRecord, 201, 209)) / 1000000.0 );

    if( !AddShapePoints( poFeature->GetFieldAsInteger("TLID"), nRecordId,
                         poLine, 0 ) )
    {
        delete poFeature;
        return NULL;
    }
    
    poLine->addPoint(atoi(GetField(achRecord, 210, 219)) / 1000000.0,
                     atoi(GetField(achRecord, 220, 228)) / 1000000.0 );

    poFeature->SetGeometryDirectly( poLine );

    return poFeature;
}

/************************************************************************/
/*                           AddShapePoints()                           */
/*                                                                      */
/*      Record zero or more shape records associated with this line     */
/*      and add the points to the passed line geometry.                 */
/************************************************************************/

int TigerCompleteChain::AddShapePoints( int nTLID, int nRecordId,
                                        OGRLineString * poLine, int nSeqNum ) 

{
    int         nShapeRecId;

    nShapeRecId = GetShapeRecordId( nRecordId, nTLID );

    // -2 means an error occured.
    if( nShapeRecId == -2 )
        return FALSE;

    // -1 means there are no extra shape vertices, but things worked fine.
    if( nShapeRecId == -1 )
        return TRUE;

/* -------------------------------------------------------------------- */
/*      Read all the sequential records with the same TLID.             */
/* -------------------------------------------------------------------- */
    char        achShapeRec[OGR_TIGER_RECBUF_LEN];
    int         nShapeRecLen = psRT2Info->nRecordLength + nRecordLength - psRT1Info->nRecordLength;

    for( ; TRUE; nShapeRecId++ )
    {
        int  nBytesRead = 0;

        if( VSIFSeek( fpShape, (nShapeRecId-1) * nShapeRecLen,
                      SEEK_SET ) != 0 )
        {
            CPLError( CE_Failure, CPLE_FileIO,
                      "Failed to seek to %d of %s2",
                      (nShapeRecId-1) * nShapeRecLen, pszModule );
            return FALSE;
        }