C++ OGRFeature::StealGeometry方法代码示例

OGRFeature *OGRWarpedLayer::GetNextFeature()
{
    while(TRUE)
    {
        OGRFeature* poFeature = m_poDecoratedLayer->GetNextFeature();
        if( poFeature == NULL )
            return NULL;

        OGRGeometry* poGeom = poFeature->GetGeometryRef();
        if( poGeom == NULL )
            return poFeature;

        if( poGeom->transform(m_poCT) != OGRERR_NONE )
        {
            delete poFeature->StealGeometry();
        }
        else
        {
            if( m_poFilterGeom != NULL && !FilterGeometry( poGeom ) )
            {
                delete poFeature;
                continue;
            }
        }
        return poFeature;
    }
}

OGRFeature *OGRWarpedLayer::GetFeature( long nFID )
{
    OGRFeature* poFeature = m_poDecoratedLayer->GetFeature(nFID);
    if( poFeature != NULL )
    {
        OGRGeometry* poGeom = poFeature->GetGeometryRef();
        if( poGeom != NULL && poGeom->transform(m_poCT) != OGRERR_NONE )
        {
            delete poFeature->StealGeometry();
        }
    }
    return poFeature;
}

OGRFeature *OGRWarpedLayer::SrcFeatureToWarpedFeature(OGRFeature* poSrcFeature)
{
    OGRFeature* poFeature = new OGRFeature(GetLayerDefn());
    poFeature->SetFrom(poSrcFeature);
    poFeature->SetFID(poSrcFeature->GetFID());

    OGRGeometry* poGeom = poFeature->GetGeomFieldRef(m_iGeomField);
    if( poGeom == NULL )
        return poFeature;

    if( poGeom->transform(m_poCT) != OGRERR_NONE )
    {
        delete poFeature->StealGeometry(m_iGeomField);
    }

    return poFeature;
}

OGRFeature* OGRPLScenesLayer::GetNextRawFeature()
{
    if( bEOF ||
        (!bFilterMustBeClientSideEvaluated && nFeatureCount >= 0 && nNextFID > nFeatureCount) )
        return NULL;

    if( poGeoJSONLayer == NULL )
    {
        if( !GetNextPage() )
            return NULL;
    }

#ifdef notdef
    if( CSLTestBoolean(CPLGetConfigOption("OGR_LIMIT_TOO_MANY_FEATURES", "FALSE")) &&
        nFeatureCount > nPageSize )
    {
        bEOF = TRUE;
        OGRFeature* poFeature = new OGRFeature(poFeatureDefn);
        OGRGeometry* poGeom;
        const char* pszWKT = "MULTIPOLYGON(((-180 90,180 90,180 -90,-180 -90,-180 90)))";
        OGRGeometryFactory::createFromWkt((char**)&pszWKT, poSRS, &poGeom);
        poFeature->SetGeometryDirectly(poGeom);
        return poFeature;
    }
#endif

    OGRFeature* poGeoJSONFeature = poGeoJSONLayer->GetNextFeature();
    if( poGeoJSONFeature == NULL )
    {
        osRequestURL = osNextURL;
        bStillInFirstPage = FALSE;
        if( !GetNextPage() )
            return NULL;
        poGeoJSONFeature = poGeoJSONLayer->GetNextFeature();
        if( poGeoJSONFeature == NULL )
        {
            bEOF = TRUE;
            return NULL;
        }
    }
    OGRFeature* poFeature = new OGRFeature(poFeatureDefn);
    poFeature->SetFID(nNextFID++);

    OGRGeometry* poGeom = poGeoJSONFeature->StealGeometry();
    if( poGeom != NULL )
    {
        if( poGeom->getGeometryType() == wkbPolygon )
        {
            OGRMultiPolygon* poMP = new OGRMultiPolygon();
            poMP->addGeometryDirectly(poGeom);
            poGeom = poMP;
        }
        poGeom->assignSpatialReference(poSRS);
        poFeature->SetGeometryDirectly(poGeom);
    }
    
    for(int i=0;i<poFeatureDefn->GetFieldCount();i++)
    {
        OGRFieldDefn* poFieldDefn = poFeatureDefn->GetFieldDefn(i);
        OGRFieldType eType = poFieldDefn->GetType();
        int iSrcField = poGeoJSONFeature->GetFieldIndex(poFieldDefn->GetNameRef());
        if( iSrcField >= 0 && poGeoJSONFeature->IsFieldSet(iSrcField) )
        {
            if( eType == OFTInteger )
                poFeature->SetField(i,
                    poGeoJSONFeature->GetFieldAsInteger(iSrcField));
            else if( eType == OFTReal )
                poFeature->SetField(i,
                    poGeoJSONFeature->GetFieldAsDouble(iSrcField));
            else
                poFeature->SetField(i,
                    poGeoJSONFeature->GetFieldAsString(iSrcField));
        }
    }

    delete poGeoJSONFeature;

    return poFeature;
}

void OGRDXFDataSource::ReadBlocksSection()

{
    char szLineBuf[257];
    int  nCode;
    OGRDXFLayer *poReaderLayer = (OGRDXFLayer *) GetLayerByName( "Entities" );

    iEntitiesSectionOffset = oReader.iSrcBufferFileOffset + oReader.iSrcBufferOffset;

    while( (nCode = ReadValue( szLineBuf, sizeof(szLineBuf) )) > -1 
           && !EQUAL(szLineBuf,"ENDSEC") )
    {
        // We are only interested in extracting blocks.
        if( nCode != 0 || !EQUAL(szLineBuf,"BLOCK") )
            continue;

        // Process contents of BLOCK definition till we find the 
        // first entity.
        CPLString osBlockName;

        while( (nCode = ReadValue( szLineBuf,sizeof(szLineBuf) )) > 0 )
        {
            if( nCode == 2 )
                osBlockName = szLineBuf;

            // anything else we want? 
        }

        if( EQUAL(szLineBuf,"ENDBLK") )
            continue;

        UnreadValue();

        // Now we will process entities till we run out at the ENDBLK code.
        // we aggregate the geometries of the features into a multi-geometry,
        // but throw away other stuff attached to the features.

        OGRFeature *poFeature;
        OGRGeometryCollection *poColl = new OGRGeometryCollection();
        std::vector<OGRFeature*> apoFeatures;

        while( (poFeature = poReaderLayer->GetNextUnfilteredFeature()) != NULL )
        {
            if( poFeature->GetStyleString() != NULL
                && strstr(poFeature->GetStyleString(),"LABEL") != NULL )
            {
                apoFeatures.push_back( poFeature );
            }
            else
            {
                poColl->addGeometryDirectly( poFeature->StealGeometry() );
                delete poFeature;
            }
        }

        if( poColl->getNumGeometries() == 0 )
            delete poColl;
        else
            oBlockMap[osBlockName].poGeometry = SimplifyBlockGeometry(poColl);

        if( apoFeatures.size() > 0 )
            oBlockMap[osBlockName].apoFeatures = apoFeatures;
    }

    CPLDebug( "DXF", "Read %d blocks with meaningful geometry.", 
              (int) oBlockMap.size() );
}

void OGRDWGDataSource::ReadBlocksSection()

{
    OGRDWGLayer *poReaderLayer = (OGRDWGLayer *) GetLayerByName( "Entities" );
    int bMergeBlockGeometries = CSLTestBoolean(
        CPLGetConfigOption( "DWG_MERGE_BLOCK_GEOMETRIES", "TRUE" ) );

/* -------------------------------------------------------------------- */
/*      Loop over all the block tables, skipping *Model_Space which     */
/*      we assume is primary entities.                                  */
/* -------------------------------------------------------------------- */
    OdDbBlockTableRecordPtr  poModelSpace, poBlock;
    OdDbBlockTablePtr pTable = GetDB()->getBlockTableId().safeOpenObject();
    OdDbSymbolTableIteratorPtr pBlkIter = pTable->newIterator();
    
    for (pBlkIter->start(); ! pBlkIter->done(); pBlkIter->step())
    {
        poBlock = pBlkIter->getRecordId().safeOpenObject();
        CPLString osBlockName = (const char *) poBlock->getName();

        if( EQUAL(osBlockName,"*Model_Space") )
        {
            poModelSpace = poBlock;
            continue;
        }

        poReaderLayer->SetBlockTable( poBlock );

        // Now we will process entities till we run out.
        // We aggregate the geometries of the features into a multi-geometry,
        // but throw away other stuff attached to the features.

        OGRFeature *poFeature;
        OGRGeometryCollection *poColl = new OGRGeometryCollection();
        std::vector<OGRFeature*> apoFeatures;

        while( (poFeature = poReaderLayer->GetNextUnfilteredFeature()) != NULL )
        {
            if( (poFeature->GetStyleString() != NULL
                 && strstr(poFeature->GetStyleString(),"LABEL") != NULL)
                || !bMergeBlockGeometries )
            {
                apoFeatures.push_back( poFeature );
            }
            else
            {
                poColl->addGeometryDirectly( poFeature->StealGeometry() );
                delete poFeature;
            }
        }

        if( poColl->getNumGeometries() == 0 )
            delete poColl;
        else
            oBlockMap[osBlockName].poGeometry = SimplifyBlockGeometry(poColl);

        if( apoFeatures.size() > 0 )
            oBlockMap[osBlockName].apoFeatures = apoFeatures;
    }

    CPLDebug( "DWG", "Read %d blocks with meaningful geometry.", 
              (int) oBlockMap.size() );

    poReaderLayer->SetBlockTable( poModelSpace );
}

bool GdaCache::CacheLayer(std::string ext_ds_name, 
						  OGRLayerProxy* ext_layer_proxy)
{
	OGRLayer* poSrcLayer = ext_layer_proxy->layer;
	
	// get information from current layer: geomtype, layer_name
    // (NOTE: we don't consider coodinator system and translation here)
    OGRFeatureDefn *poSrcFDefn = poSrcLayer->GetLayerDefn();
    int eGType = poSrcFDefn->GetGeomType();
    const char* pszNewLayerName = poSrcLayer->GetName();
    int bForceToPolygon = FALSE;
    int bForceToMultiPolygon = FALSE;
    int bForceToMultiLineString = FALSE;
	
    if( wkbFlatten(eGType) == wkbPolygon )
        bForceToPolygon = TRUE;
    else if( wkbFlatten(eGType) == wkbMultiPolygon )
        bForceToMultiPolygon = TRUE;
    else if( wkbFlatten(eGType) == wkbMultiLineString )
        bForceToMultiLineString = TRUE;
	
	//Setup coordinate transformation if we need it.
	OGRCoordinateTransformation *poCT = NULL;
	bool bTransform                   = FALSE;
	OGRSpatialReference *poSourceSRS = NULL;
	// todo
	OGRSpatialReference *poOutputSRS = new OGRSpatialReference("EPSG:4326");

	// Cache
	char *papszLCO[] = {"OVERWRITE=yes","FORMAT=Spatialite"};
	std::string cache_layer_name = ext_ds_name + "_"+ext_layer_proxy->name;
    OGRDataSource *poDstDS = cach_ds_proxy->ds;
    OGRLayer *poDstLayer = poDstDS->CreateLayer(cache_layer_name.c_str(), 
												poOutputSRS, 
												(OGRwkbGeometryType)eGType, 
												papszLCO);
	if (poDstLayer == NULL) {
		// raise create cache failed.
		return false;
	}
    // Process Layer style table
    poDstLayer->SetStyleTable( poSrcLayer->GetStyleTable () );
	
    // Add fields. here to copy all field.
    int nSrcFieldCount = poSrcFDefn->GetFieldCount();
    int iField;
    OGRFeatureDefn *poDstFDefn = poDstLayer->GetLayerDefn();
	
    for( iField = 0; iField < nSrcFieldCount; iField++ )
    {    
        OGRFieldDefn* poSrcFieldDefn = poSrcFDefn->GetFieldDefn(iField);
        OGRFieldDefn oFieldDefn( poSrcFieldDefn );
		
        // The field may have been already created at layer creation 
		if (poDstLayer->CreateField( &oFieldDefn ) == OGRERR_NONE)
        {    
            // now that we've created a field, GetLayerDefn() won't return NULL
            if (poDstFDefn == NULL)
                poDstFDefn = poDstLayer->GetLayerDefn();
        }    
    }    
	
    // Transfer feature from Source Layer to Dest Layer
    OGRFeature  *poFeature;
    GIntBig      nFeaturesWritten = 0;
    poSrcLayer->ResetReading();
	
    while (poFeature = poSrcLayer->GetNextFeature())
    {
        OGRFeature *poDstFeature = OGRFeature::CreateFeature(
										poDstLayer->GetLayerDefn() );
        poDstFeature->SetFrom(poFeature);
		
        OGRGeometry *poDstGeometry = poDstFeature->GetGeometryRef();
        if (poDstGeometry != NULL)
        {
            if( bForceToPolygon )
            {
                poDstFeature->SetGeometryDirectly(
					OGRGeometryFactory::forceToPolygon(
						poDstFeature->StealGeometry()));
            }
            else if( bForceToMultiPolygon )
            {
                poDstFeature->SetGeometryDirectly(
					OGRGeometryFactory::forceToMultiPolygon(
					    poDstFeature->StealGeometry() ) );
            }
            else if ( bForceToMultiLineString )
            {
                poDstFeature->SetGeometryDirectly(
					OGRGeometryFactory::forceToMultiLineString(
						poDstFeature->StealGeometry() ) );
            }
        }
        if( poDstLayer->CreateFeature( poDstFeature ) == OGRERR_NONE )
        {
            nFeaturesWritten ++;
        }            
        OGRFeature::DestroyFeature( poDstFeature );
//.........这里部分代码省略.........