ogr2ogr.cpp

mitab,读取MapInfo的地图文件

            " -sql statement: Execute given SQL statement and save result.\n"
            " -skipfailures: skip features or layers that fail to convert\n"
            " -spat xmin ymin xmax ymax: spatial query extents\n"
            " -dsco NAME=VALUE: Dataset creation option (format specific)\n"
            " -lco  NAME=VALUE: Layer creation option (format specific)\n"
            " -nln name: Assign an alternate name to the new layer\n"
            " -nlt type: Force a geometry type for new layer.  One of NONE, GEOMETRY,\n"
            "      POINT, LINESTRING, POLYGON, GEOMETRYCOLLECTION, MULTIPOINT, MULTILINE,\n"
            "      MULTIPOLYGON, or MULTILINESTRING.  Add \"25D\" for 3D layers.\n"
            "      Default is type of source layer.\n" );

    printf(" -a_srs srs_def: Assign an output SRS\n"
           " -t_srs srs_def: Reproject/transform to this SRS on output\n"
           " -s_srs srs_def: Override source SRS\n"
           "\n" 
           " Srs_def can be a full WKT definition (hard to escape properly),\n"
           " or a well known definition (ie. EPSG:4326) or a file with a WKT\n"
           " definition.\n" );

    exit( 1 );
}

/************************************************************************/
/*                           TranslateLayer()                           */
/************************************************************************/

static int TranslateLayer( OGRDataSource *poSrcDS, 
                           OGRLayer * poSrcLayer,
                           OGRDataSource *poDstDS,
                           char **papszLCO,
                           const char *pszNewLayerName,
                           int bTransform, 
                           OGRSpatialReference *poOutputSRS,
                           OGRSpatialReference *poSourceSRS,
                           char **papszSelFields,
                           int bAppend, int eGType )

{
    OGRLayer    *poDstLayer;
    OGRFeatureDefn *poFDefn;
    OGRErr      eErr;
    int         bForceToPolygon = FALSE;
    int         bForceToMultiPolygon = FALSE;

    if( pszNewLayerName == NULL )
        pszNewLayerName = poSrcLayer->GetLayerDefn()->GetName();

    if( wkbFlatten(eGType) == wkbPolygon )
        bForceToPolygon = TRUE;
    else if( wkbFlatten(eGType) == wkbMultiPolygon )
        bForceToMultiPolygon = TRUE;

/* -------------------------------------------------------------------- */
/*      Setup coordinate transformation if we need it.                  */
/* -------------------------------------------------------------------- */
    OGRCoordinateTransformation *poCT = NULL;

    if( bTransform )
    {
        if( poSourceSRS == NULL )
            poSourceSRS = poSrcLayer->GetSpatialRef();

        if( poSourceSRS == NULL )
        {
            printf( "Can't transform coordinates, source layer has no\n"
                    "coordinate system.  Use -s_srs to set one.\n" );
            exit( 1 );
        }

        poCT = OGRCreateCoordinateTransformation( poSourceSRS, poOutputSRS );
        if( poCT == NULL )
        {
            char        *pszWKT = NULL;

            printf("Failed to create coordinate transformation between the\n"
                   "following coordinate systems.  This may be because they\n"
                   "are not transformable, or because projection services\n"
                   "(PROJ.4 DLL/.so) could not be loaded.\n" );
            
            poSrcLayer->GetSpatialRef()->exportToPrettyWkt( &pszWKT, FALSE );
            printf( "Source:\n%s\n", pszWKT );
            
            poOutputSRS->exportToPrettyWkt( &pszWKT, FALSE );
            printf( "Target:\n%s\n", pszWKT );
            exit( 1 );
        }
    }
    
/* -------------------------------------------------------------------- */
/*      Get other info.                                                 */
/* -------------------------------------------------------------------- */
    poFDefn = poSrcLayer->GetLayerDefn();
    
    if( poOutputSRS == NULL )
        poOutputSRS = poSrcLayer->GetSpatialRef();
    
/* -------------------------------------------------------------------- */
/*      Create the layer.                                               */
/* -------------------------------------------------------------------- */
    if( !bAppend )
    {
        if( eGType == -2 )
            eGType = poFDefn->GetGeomType();

        CPLAssert( poDstDS->TestCapability( ODsCCreateLayer ) );
        CPLErrorReset();

        poDstLayer = poDstDS->CreateLayer( pszNewLayerName, poOutputSRS,
                                           (OGRwkbGeometryType) eGType, 
                                           papszLCO );

        if( poDstLayer == NULL )
            return FALSE;
    }
/* -------------------------------------------------------------------- */
/*      Or find existing layer to append to.                            */
/* -------------------------------------------------------------------- */
    else
    {
        poDstLayer = NULL;

        for( int iLayer = 0; iLayer < poDstDS->GetLayerCount(); iLayer++ )
        {
            OGRLayer        *poLayer = poDstDS->GetLayer(iLayer);

            if( poLayer != NULL 
                && EQUAL(poLayer->GetLayerDefn()->GetName(),pszNewLayerName) )
            {
                poDstLayer = poLayer;
                break;
            }
        }

        if( poDstLayer == NULL )
        {
            printf( "FAILED: To find existing layer `%s' on output dataset\n"
                    "        to append new features to.\n",
                    pszNewLayerName );
            return FALSE;
        }
    }

/* -------------------------------------------------------------------- */
/*      Add fields.  Default to copy all field.                         */
/*      If only a subset of all fields requested, then output only      */
/*      the selected fields, and in the order that they were            */
/*      selected.                                                       */
/* -------------------------------------------------------------------- */
    int         iField;

    if (papszSelFields && !bAppend )
    {
        for( iField=0; papszSelFields[iField] != NULL; iField++)
        {
            int iSrcField = poFDefn->GetFieldIndex(papszSelFields[iField]);
            if (iSrcField >= 0)
                poDstLayer->CreateField( poFDefn->GetFieldDefn(iSrcField) );
            else
            {
                printf( "Field '%s' not found in source layer.\n", 
                         papszSelFields[iField] );
                if( !bSkipFailures )
                    return FALSE;
            }
        }
    }
    else if( !bAppend )
    {
        for( iField = 0; iField < poFDefn->GetFieldCount(); iField++ )
            poDstLayer->CreateField( poFDefn->GetFieldDefn(iField) );
    }

/* -------------------------------------------------------------------- */
/*      Transfer features.                                              */
/* -------------------------------------------------------------------- */
    OGRFeature  *poFeature;
    int         nFeaturesInTransaction = 0;
    
    poSrcLayer->ResetReading();

    if( nGroupTransactions )
        poDstLayer->StartTransaction();

    while( TRUE )
    {
        OGRFeature      *poDstFeature = NULL;

        if( nFIDToFetch != OGRNullFID )
        {
            // Only fetch feature on first pass.
            if( nFeaturesInTransaction == 0 )
                poFeature = poSrcLayer->GetFeature(nFIDToFetch);
            else
                poFeature = NULL;
        }
        else
            poFeature = poSrcLayer->GetNextFeature();
        
        if( poFeature == NULL )
            break;

        if( ++nFeaturesInTransaction == nGroupTransactions )
        {
            poDstLayer->CommitTransaction();
            poDstLayer->StartTransaction();
            nFeaturesInTransaction = 0;
        }

        CPLErrorReset();
        poDstFeature = OGRFeature::CreateFeature( poDstLayer->GetLayerDefn() );

        if( poDstFeature->SetFrom( poFeature, TRUE ) != OGRERR_NONE )
        {
            if( nGroupTransactions )
                poDstLayer->CommitTransaction();
            
            CPLError( CE_Failure, CPLE_AppDefined,
                      "Unable to translate feature %d from layer %s.\n",
                      poFeature->GetFID(), poFDefn->GetName() );
            
            OGRFeature::DestroyFeature( poFeature );
            OGRFeature::DestroyFeature( poDstFeature );
            return FALSE;
        }

        if( bPreserveFID )
            poDstFeature->SetFID( poFeature->GetFID() );
        
        if( poCT && poDstFeature->GetGeometryRef() != NULL )
        {
            eErr = poDstFeature->GetGeometryRef()->transform( poCT );
            if( eErr != OGRERR_NONE )
            {
                if( nGroupTransactions )
                    poDstLayer->CommitTransaction();

                printf( "Failed to transform feature %d.\n", 
                        (int) poFeature->GetFID() );
                if( !bSkipFailures )
                {
                    OGRFeature::DestroyFeature( poFeature );
                    OGRFeature::DestroyFeature( poDstFeature );
                    return FALSE;
                }
            }
        }

        if( poDstFeature->GetGeometryRef() != NULL && bForceToPolygon )
        {
            poDstFeature->SetGeometryDirectly( 
                OGRGeometryFactory::forceToPolygon(
                    poDstFeature->StealGeometry() ) );
        }
                    
        if( poDstFeature->GetGeometryRef() != NULL && bForceToMultiPolygon )
        {
            poDstFeature->SetGeometryDirectly( 
                OGRGeometryFactory::forceToMultiPolygon(
                    poDstFeature->StealGeometry() ) );
        }
                    
        OGRFeature::DestroyFeature( poFeature );

        CPLErrorReset();
        if( poDstLayer->CreateFeature( poDstFeature ) != OGRERR_NONE 
            && !bSkipFailures )
        {
            if( nGroupTransactions )
                poDstLayer->RollbackTransaction();

            OGRFeature::DestroyFeature( poDstFeature );
            return FALSE;
        }

        OGRFeature::DestroyFeature( poDstFeature );
    }

    if( nGroupTransactions )
        poDstLayer->CommitTransaction();

    return TRUE;
}