ogridblayer.cpp

来自「支持各种栅格图像和矢量图像读取的库」· C++ 代码 · 共 463 行 · 第 1/2 页

OGRFeature *OGRIDBLayer::GetNextFeature()

{
    for( ; TRUE; )
    {
        OGRFeature      *poFeature;

        poFeature = GetNextRawFeature();
        if( poFeature == NULL )
            return NULL;

        if( (m_poFilterGeom == NULL
            || FilterGeometry( poFeature->GetGeometryRef() ) )
            && (m_poAttrQuery == NULL
                || m_poAttrQuery->Evaluate( poFeature )) )
            return poFeature;

        delete poFeature;
    }
}

/************************************************************************/
/*                         GetNextRawFeature()                          */
/************************************************************************/

OGRFeature *OGRIDBLayer::GetNextRawFeature()

{
    if( GetQuery() == NULL )
        return NULL;

/* -------------------------------------------------------------------- */
/*      If we are marked to restart then do so, and fetch a record.     */
/* -------------------------------------------------------------------- */
    ITRow * row = poCurr->NextRow();
    if ( ! row )
    {
        delete poCurr;
        poCurr = NULL;
        return NULL;
    }

    iNextShapeId++;
    m_nFeaturesRead++;

/* -------------------------------------------------------------------- */
/*      Create a feature from the current result.                       */
/* -------------------------------------------------------------------- */
    int         iField;
    OGRFeature *poFeature = new OGRFeature( poFeatureDefn );

    const ITTypeInfo * poRowType = poCurr->RowType();
    int nFieldCount = poRowType->ColumnCount();

    for ( iField = 0; iField < nFieldCount; iField++ )
    {
/* -------------------------------------------------------------------- */
/*      Handle FID column                                               */
/* -------------------------------------------------------------------- */
        if ( pszFIDColumn != NULL &&
             EQUAL( poRowType->ColumnName( iField ), pszFIDColumn ) )
            poFeature->SetFID( atoi( row->Column( iField )->Printable() ) );

/* -------------------------------------------------------------------- */
/*      Handle geometry                                                 */
/* -------------------------------------------------------------------- */
        if( pszGeomColumn != NULL &&
            EQUAL( poRowType->ColumnName( iField ), pszGeomColumn ) )
        {
            OGRGeometry *poGeom = NULL;
            OGRErr eErr = OGRERR_NONE;

            ITValue * v = row->Column( iField );

            if( ! v->IsNull() && ! bGeomColumnWKB )
            {
                const char *pszGeomText = v->Printable();
                if ( pszGeomText != NULL )
                eErr =
                    OGRGeometryFactory::createFromWkt((char **) &pszGeomText,
                                                    poSRS, &poGeom);
            }
            else if( ! v->IsNull() && bGeomColumnWKB )
            {
                ITDatum *rv = 0;
                if ( v->QueryInterface( ITDatumIID, (void **) &rv ) ==
                     IT_QUERYINTERFACE_SUCCESS )
                {
                    int nLength = rv->DataLength();
                    unsigned char * wkb = (unsigned char *)rv->Data();

                    eErr = OGRGeometryFactory::createFromWkb( wkb, poSRS, &poGeom, nLength);
                    rv->Release();
                }
            }

            v->Release();


            if ( eErr != OGRERR_NONE )
            {
                const char *pszMessage;

                switch ( eErr )
                {
                    case OGRERR_NOT_ENOUGH_DATA:
                        pszMessage = "Not enough data to deserialize";
                        break;
                    case OGRERR_UNSUPPORTED_GEOMETRY_TYPE:
                        pszMessage = "Unsupported geometry type";
                        break;
                    case OGRERR_CORRUPT_DATA:
                        pszMessage = "Corrupt data";
                    default:
                        pszMessage = "Unrecognized error";
                }
                CPLError(CE_Failure, CPLE_AppDefined,
                        "GetNextRawFeature(): %s", pszMessage);
            }

            if( poGeom != NULL )
            {
                poFeature->SetGeometryDirectly( poGeom );
            }

            continue;
        }

/* -------------------------------------------------------------------- */
/*      Transfer regular data fields.                                   */
/* -------------------------------------------------------------------- */
        int iOGRField =
            poFeatureDefn->GetFieldIndex( poRowType->ColumnName( iField ) );

        if( iOGRField < 0 )
            continue;

        const char * pszColData = row->Column( iField )->Printable();

        if( ! pszColData  )
            continue;

        if( poFeatureDefn->GetFieldDefn(iOGRField)->GetType() == OFTBinary )
            poFeature->SetField( iOGRField,
                                 poRowType->ColumnType( iField )->Size(),
                                 (GByte *) pszColData );
        else
            poFeature->SetField( iOGRField, pszColData );
    }

    row->Release();
    return poFeature;
}

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

OGRFeature *OGRIDBLayer::GetFeature( long nFeatureId )

{
    /* This should be implemented directly! */

    return OGRLayer::GetFeature( nFeatureId );
}

/************************************************************************/
/*                           TestCapability()                           */
/************************************************************************/

int OGRIDBLayer::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,OLCRandomRead) )
        return FALSE;

    else if( EQUAL(pszCap,OLCFastFeatureCount) )
        return FALSE;

    else if( EQUAL(pszCap,OLCFastSpatialFilter) )
        return FALSE;

    else if( EQUAL(pszCap,OLCTransactions) )
        return FALSE;

    else
        return FALSE;
}

/************************************************************************/
/*                           GetSpatialRef()                            */
/************************************************************************/

OGRSpatialReference *OGRIDBLayer::GetSpatialRef()

{
    return poSRS;
}

/************************************************************************/
/*                            GetFIDColumn()                            */
/************************************************************************/

const char *OGRIDBLayer::GetFIDColumn()

{
    if( pszFIDColumn != NULL )
        return pszFIDColumn;
    else
        return "";
}

/************************************************************************/
/*                         GetGeometryColumn()                          */
/************************************************************************/

const char *OGRIDBLayer::GetGeometryColumn()

{
    if( pszGeomColumn != NULL )
        return pszGeomColumn;
    else
        return "";
}

/* TODO Query to get layer extent */
/*
EXECUTE FUNCTION SE_BoundingBox ('table_name', 'geom_column' )
*/