tigercompletechain.cpp

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

        nBytesRead = VSIFRead( achShapeRec, 1, psRT2Info->nRecordLength, 
                               fpShape );

        /* 
        ** Handle case where the last record in the file is full.  We will
        ** try to read another record but not find it.  We require that we
        ** have found at least one shape record for this case though. 
        */
        if( nBytesRead <= 0 && VSIFEof( fpShape ) 
            && poLine->getNumPoints() > 0 )
            break;

        if( nBytesRead != psRT2Info->nRecordLength )
        {
            CPLError( CE_Failure, CPLE_FileIO,
                      "Failed to read %d bytes of record %d of %s2 at offset %d",
                      psRT2Info->nRecordLength, nShapeRecId, pszModule,
                      (nShapeRecId-1) * nShapeRecLen );
            return FALSE;
        }

        if( atoi(GetField(achShapeRec,6,15)) != nTLID )
            break;

/* -------------------------------------------------------------------- */
/*      Translate the locations into OGRLineString vertices.            */
/* -------------------------------------------------------------------- */
        int     iVertex;

        for( iVertex = 0; iVertex < 10; iVertex++ )
        {
            int         iStart = 19 + 19*iVertex;
            int         nX = atoi(GetField(achShapeRec,iStart,iStart+9));
            int         nY = atoi(GetField(achShapeRec,iStart+10,iStart+18));

            if( nX == 0 && nY == 0 )
                break;

            poLine->addPoint( nX / 1000000.0, nY / 1000000.0 );
        }

/* -------------------------------------------------------------------- */
/*      Don't get another record if this one was incomplete.            */
/* -------------------------------------------------------------------- */
        if( iVertex < 10 )
            break;
    }

    return TRUE;
}

/************************************************************************/
/*                          GetShapeRecordId()                          */
/*                                                                      */
/*      Get the record id of the first record of shape points for       */
/*      the provided TLID (complete chain).                             */
/************************************************************************/

int TigerCompleteChain::GetShapeRecordId( int nChainId, int nTLID )

{
    CPLAssert( nChainId >= 0 && nChainId < GetFeatureCount() );

    if( fpShape == NULL || panShapeRecordId == NULL )
        return -1;
    
/* -------------------------------------------------------------------- */
/*      Do we already have the answer?                                  */
/* -------------------------------------------------------------------- */
    if( panShapeRecordId[nChainId] != 0 )
        return panShapeRecordId[nChainId];
    
/* -------------------------------------------------------------------- */
/*      If we don't already have this value, then search from the       */
/*      previous known record.                                          */
/* -------------------------------------------------------------------- */
    int iTestChain, nWorkingRecId;
        
    for( iTestChain = nChainId-1;
         iTestChain >= 0 && panShapeRecordId[iTestChain] <= 0;
         iTestChain-- ) {}

    if( iTestChain < 0 )
    {
        iTestChain = -1;
        nWorkingRecId = 1;
    }
    else
    {
        nWorkingRecId = panShapeRecordId[iTestChain]+1;
    }

/* -------------------------------------------------------------------- */
/*      If we have non existent records following (-1's) we can         */
/*      narrow our search a bit.                                        */
/* -------------------------------------------------------------------- */
    while( panShapeRecordId[iTestChain+1] == -1 )
    {
        iTestChain++;
    }

/* -------------------------------------------------------------------- */
/*      Read records up to the maximum distance that is possibly        */
/*      required, looking for our target TLID.                          */
/* -------------------------------------------------------------------- */
    int         nMaxChainToRead = nChainId - iTestChain;
    int         nChainsRead = 0;
    char        achShapeRec[OGR_TIGER_RECBUF_LEN];
    int         nShapeRecLen = psRT2Info->nRecordLength + nRecordLength - psRT1Info->nRecordLength;

    while( nChainsRead < nMaxChainToRead )
    {
        if( VSIFSeek( fpShape, (nWorkingRecId-1) * nShapeRecLen,
                      SEEK_SET ) != 0 )
        {
            CPLError( CE_Failure, CPLE_FileIO,
                      "Failed to seek to %d of %s2",
                      (nWorkingRecId-1) * nShapeRecLen, pszModule );
            return -2;
        }

        if( VSIFRead( achShapeRec, psRT2Info->nRecordLength, 1, fpShape ) != 1 )
        {
            if( !VSIFEof( fpShape ) )
            {
                CPLError( CE_Failure, CPLE_FileIO,
                          "Failed to read record %d of %s2",
                          nWorkingRecId-1, pszModule );
                return -2;
            }
            else
                return -1;
        }

        if( atoi(GetField(achShapeRec,6,15)) == nTLID )
        {
            panShapeRecordId[nChainId] = nWorkingRecId;

            return nWorkingRecId;
        }

        if( atoi(GetField(achShapeRec,16,18)) == 1 )
        {
            nChainsRead++;
        }

        nWorkingRecId++;
    }

    panShapeRecordId[nChainId] = -1;

    return -1;
}

/************************************************************************/
/*                           SetWriteModule()                           */
/************************************************************************/
int TigerCompleteChain::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( bUsingRT3 )
    {
        if( fpRT3 != NULL )
        {
            VSIFClose( fpRT3 );
            fpRT3 = NULL;
        }

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

            fpRT3 = VSIFOpen( pszFilename, "ab" );

            CPLFree( pszFilename );
        }
    }
    
/* -------------------------------------------------------------------- */
/*      Close the shape point file, if open and free the list of        */
/*      record ids.                                                     */
/* -------------------------------------------------------------------- */
    if( fpShape != NULL )
    {
        VSIFClose( fpShape );
        fpShape = NULL;
    }
    
    if( pszModule )
    {
        char        *pszFilename;
        
        pszFilename = poDS->BuildFilename( pszModule, "2" );
        
        fpShape = VSIFOpen( pszFilename, "ab" );
        
        CPLFree( pszFilename );
    }

    return TRUE;
}

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

OGRErr TigerCompleteChain::CreateFeature( OGRFeature *poFeature )

{
    char        szRecord[OGR_TIGER_RECBUF_LEN];
    OGRLineString *poLine = (OGRLineString *) poFeature->GetGeometryRef();

    if( poLine == NULL 
        || (poLine->getGeometryType() != wkbLineString
            && poLine->getGeometryType() != wkbLineString25D) )
        return OGRERR_FAILURE;

    /* -------------------------------------------------------------------- */
    /*      Write basic data record ("RT1")                                 */
    /* -------------------------------------------------------------------- */
    if( !SetWriteModule( "1", psRT1Info->nRecordLength+2, poFeature ) )
        return OGRERR_FAILURE;
    memset( szRecord, ' ', psRT1Info->nRecordLength );
    WriteFields( psRT1Info, poFeature, szRecord );
    WritePoint( szRecord, 191, poLine->getX(0), poLine->getY(0) );
    WritePoint( szRecord, 210, 
                poLine->getX(poLine->getNumPoints()-1), 
                poLine->getY(poLine->getNumPoints()-1) );
    WriteRecord( szRecord, psRT1Info->nRecordLength, "1" );

    /* -------------------------------------------------------------------- */
    /*      Write geographic entity codes (RT3)                             */
    /* -------------------------------------------------------------------- */
    if (bUsingRT3) {
      memset( szRecord, ' ', psRT3Info->nRecordLength );
      WriteFields( psRT3Info, poFeature, szRecord );
      WriteRecord( szRecord, psRT3Info->nRecordLength, "3", fpRT3 );
    }

    /* -------------------------------------------------------------------- */
    /*      Write shapes sections (RT2)                                     */
    /* -------------------------------------------------------------------- */
    if( poLine->getNumPoints() > 2 )
    {
        int     nPoints = poLine->getNumPoints();
        int     iPoint, nRTSQ = 1;

        for( iPoint = 1; iPoint < nPoints-1; )
        {
            int         i;
            char        szTemp[5];

            memset( szRecord, ' ', psRT2Info->nRecordLength );

            WriteField( poFeature, "TLID", szRecord, 6, 15, 'R', 'N' );
            
            sprintf( szTemp, "%3d", nRTSQ );
            strncpy( ((char *)szRecord) + 15, szTemp, 4 );

            for( i = 0; i < 10; i++ )
            {
                if( iPoint < nPoints-1 )
                    WritePoint( szRecord, 19+19*i, 
                                poLine->getX(iPoint), poLine->getY(iPoint) );
                else
                    WritePoint( szRecord, 19+19*i, 0.0, 0.0 );

                iPoint++;
            }
            
            WriteRecord( szRecord, psRT2Info->nRecordLength, "2", fpShape );

            nRTSQ++;
        }
    }

    return OGRERR_NONE;
}