bool QgsOgrFeatureIterator::fetchFeatureWithId( QgsFeatureId id, QgsFeature &feature ) const
{
feature.setValid( false );
gdal::ogr_feature_unique_ptr fet;
#if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,2,0)
if ( !QgsOgrProviderUtils::canDriverShareSameDatasetAmongLayers( mSource->mDriverName ) )
{
OGRLayerH nextFeatureBelongingLayer;
bool found = false;
// First pass: try to read from the last feature, in the hope the dataset
// returns them in increasing feature id number (and as we use a std::set
// for mFilterFids, we get them in increasing number by the iterator)
// Second pass: reset before reading
for ( int passNumber = 0; passNumber < 2; passNumber++ )
{
while ( fet.reset( GDALDatasetGetNextFeature(
mConn->ds, &nextFeatureBelongingLayer, nullptr, nullptr, nullptr ) ), fet )
{
if ( nextFeatureBelongingLayer == mOgrLayer )
{
if ( OGR_F_GetFID( fet.get() ) == FID_TO_NUMBER( id ) )
{
found = true;
break;
}
}
}
if ( found || passNumber == 1 )
{
break;
}
GDALDatasetResetReading( mConn->ds );
}
if ( !found )
{
return false;
}
}
else
#endif
{
fet.reset( OGR_L_GetFeature( mOgrLayer, FID_TO_NUMBER( id ) ) );
}
if ( !fet )
{
return false;
}
if ( !readFeature( std::move( fet ), feature ) )
return false;
feature.setValid( true );
geometryToDestinationCrs( feature, mTransform );
return true;
}
/*!
\brief Read feature from OGR layer at given offset (level 1)
This function implements random access on level 1.
\param Map pointer to Map_info structure
\param[out] line_p container used to store line points within
\param[out] line_c container used to store line categories within
\param offset given offset
\return line type
\return 0 dead line
\return -2 no more features
\return -1 out of memory
*/
int V1_read_line_ogr(struct Map_info *Map,
struct line_pnts *line_p, struct line_cats *line_c, off_t offset)
{
long FID;
int type;
OGRGeometryH hGeom;
G_debug(4, "V1_read_line_ogr() offset = %lu offset_num = %lu",
(long) offset, (long) Map->fInfo.ogr.offset_num);
if (offset >= Map->fInfo.ogr.offset_num)
return -2;
if (line_p != NULL)
Vect_reset_line(line_p);
if (line_c != NULL)
Vect_reset_cats(line_c);
FID = Map->fInfo.ogr.offset[offset];
G_debug(4, " FID = %ld", FID);
/* coordinates */
if (line_p != NULL) {
/* Read feature to cache if necessary */
if (Map->fInfo.ogr.feature_cache_id != FID) {
G_debug(4, "Read feature (FID = %ld) to cache", FID);
if (Map->fInfo.ogr.feature_cache) {
OGR_F_Destroy(Map->fInfo.ogr.feature_cache);
}
Map->fInfo.ogr.feature_cache =
OGR_L_GetFeature(Map->fInfo.ogr.layer, FID);
if (Map->fInfo.ogr.feature_cache == NULL) {
G_fatal_error(_("Unable to get feature geometry, FID %ld"),
FID);
}
Map->fInfo.ogr.feature_cache_id = FID;
}
hGeom = OGR_F_GetGeometryRef(Map->fInfo.ogr.feature_cache);
if (hGeom == NULL) {
G_fatal_error(_("Unable to get feature geometry, FID %ld"),
FID);
}
type = read_line(Map, hGeom, offset + 1, line_p);
}
else {
type = get_line_type(Map, FID);
}
/* category */
if (line_c != NULL) {
Vect_cat_set(line_c, 1, (int) FID);
}
return type;
}
bool getNextFeature()
{
if (m_current_feature)
OGR_F_Destroy(m_current_feature);
m_current_feature = OGR_L_GetFeature(m_layer, (long)m_index);
if (!m_current_feature)
return false;
m_current_geometry = OGR_F_GetGeometryRef(m_current_feature);
return true;
}
bool QgsOgrFeatureIterator::fetchFeatureWithId( QgsFeatureId id, QgsFeature& feature ) const
{
feature.setValid( false );
OGRFeatureH fet = OGR_L_GetFeature( ogrLayer, FID_TO_NUMBER( id ) );
if ( !fet )
{
return false;
}
if ( readFeature( fet, feature ) )
OGR_F_Destroy( fet );
feature.setValid( true );
return true;
}
/*!
\brief Recursively descend to feature and read the part
\param Map pointer to Map_info structure
\param hGeom OGR geometry
\param offset given offset
\param[out] Points container used to store line pointes within
\return feature type
\return -1 on error
*/
static int get_line_type(const struct Map_info *Map, long FID)
{
int eType;
OGRFeatureH hFeat;
OGRGeometryH hGeom;
G_debug(4, "get_line_type() fid = %ld", FID);
hFeat = OGR_L_GetFeature(Map->fInfo.ogr.layer, FID);
if (hFeat == NULL)
return -1;
hGeom = OGR_F_GetGeometryRef(hFeat);
if (hGeom == NULL)
return -1;
eType = wkbFlatten(OGR_G_GetGeometryType(hGeom));
OGR_F_Destroy(hFeat);
G_debug(4, "OGR Geometry of type: %d", eType);
switch (eType) {
case wkbPoint:
case wkbMultiPoint:
return GV_POINT;
break;
case wkbLineString:
case wkbMultiLineString:
return GV_LINE;
break;
case wkbPolygon:
case wkbMultiPolygon:
case wkbGeometryCollection:
return GV_BOUNDARY;
break;
default:
G_warning(_("OGR feature type %d not supported"), eType);
break;
}
return -1;
}
bool QgsOgrFeatureIterator::fetchFeature( QgsFeature& feature )
{
feature.setValid( false );
if ( mClosed )
return false;
if ( !P->mRelevantFieldsForNextFeature )
ensureRelevantFields();
if ( mRequest.filterType() == QgsFeatureRequest::FilterFid )
{
OGRFeatureH fet = OGR_L_GetFeature( ogrLayer, FID_TO_NUMBER( mRequest.filterFid() ) );
if ( !fet )
{
close();
return false;
}
if ( readFeature( fet, feature ) )
OGR_F_Destroy( fet );
feature.setValid( true );
close(); // the feature has been read: we have finished here
return true;
}
OGRFeatureH fet;
while (( fet = OGR_L_GetNextFeature( ogrLayer ) ) )
{
if ( !readFeature( fet, feature ) )
continue;
// we have a feature, end this cycle
feature.setValid( true );
OGR_F_Destroy( fet );
return true;
} // while
QgsDebugMsg( "Feature is null" );
close();
return false;
}
bool QgsOgrFeatureIterator::fetchFeature( QgsFeature& feature )
{
feature.setValid( false );
if ( mClosed )
return false;
if ( mRequest.filterType() == QgsFeatureRequest::FilterFid )
{
OGRFeatureH fet = OGR_L_GetFeature( ogrLayer, FID_TO_NUMBER( mRequest.filterFid() ) );
if ( !fet )
{
close();
return false;
}
if ( readFeature( fet, feature ) )
OGR_F_Destroy( fet );
feature.setValid( true );
close(); // the feature has been read: we have finished here
return true;
}
OGRFeatureH fet;
while (( fet = OGR_L_GetNextFeature( ogrLayer ) ) )
{
if ( !readFeature( fet, feature ) )
continue;
if ( !mRequest.filterRect().isNull() && !feature.constGeometry() )
continue;
// we have a feature, end this cycle
feature.setValid( true );
OGR_F_Destroy( fet );
return true;
} // while
close();
return false;
}
/* OGRFeatureH OGR_L_GetFeature(OGRLayerH hLayer, long nFeatureId)
{ok, DataSource} = lgeo_ogr:open("test/polygon.shp"),
{ok, Layer} = lgeo_ogr:ds_get_layer(DataSource, 0),
{ok, Feature} = lgeo_ogr:l_get_feature(Layer, 0).
*/
static ERL_NIF_TERM
l_get_feature(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{
EnvLayer_t **layer;
int index;
ERL_NIF_TERM eterm;
if(argc != 2) {
return enif_make_badarg(env);
}
if(!enif_get_resource(env, argv[0], OGR_L_RESOURCE, (void**)&layer)) {
return enif_make_badarg(env);
}
if (!enif_get_int(env, argv[1], &index)) {
return enif_make_badarg(env);
}
OGRFeatureH feat = OGR_L_GetFeature((**layer).obj, index);
if(feat == NULL) {
return enif_make_atom(env, "undefined");
}
EnvFeature_t **feature = \
enif_alloc_resource(OGR_F_RESOURCE, sizeof(EnvFeature_t*));
ErlNifEnv *feature_env = enif_alloc_env();
*feature = (EnvFeature_t*) enif_alloc(sizeof(EnvFeature_t));
(**feature).env = feature_env;
(**feature).obj = feat;
// Save copy of layer so is not garbage collected
enif_make_copy(feature_env, argv[0]);
eterm = enif_make_resource(env, feature);
enif_release_resource(feature);
return enif_make_tuple2(env, enif_make_atom(env, "ok"), eterm);
}
bool QgsOgrFeatureIterator::nextFeature( QgsFeature& feature )
{
feature.setValid( false );
if ( mClosed )
return false;
if ( !P->mRelevantFieldsForNextFeature )
ensureRelevantFields();
if ( mRequest.filterType() == QgsFeatureRequest::FilterFid )
{
OGRFeatureH fet = OGR_L_GetFeature( P->ogrLayer, FID_TO_NUMBER( mRequest.filterFid() ) );
if ( !fet )
{
close();
return false;
}
// skip features without geometry
if ( !OGR_F_GetGeometryRef( fet ) && !P->mFetchFeaturesWithoutGeom )
{
OGR_F_Destroy( fet );
close();
return false;
}
readFeature( fet, feature );
feature.setValid( true );
close(); // the feature has been read: we have finished here
return true;
}
OGRFeatureH fet;
QgsRectangle selectionRect;
while (( fet = OGR_L_GetNextFeature( P->ogrLayer ) ) )
{
// skip features without geometry
if ( !P->mFetchFeaturesWithoutGeom && !OGR_F_GetGeometryRef( fet ) )
{
OGR_F_Destroy( fet );
continue;
}
readFeature( fet, feature );
if ( mRequest.flags() & QgsFeatureRequest::ExactIntersect )
{
//precise test for intersection with search rectangle
//first make QgsRectangle from OGRPolygon
OGREnvelope env;
memset( &env, 0, sizeof( env ) );
if ( mSelectionRectangle )
OGR_G_GetEnvelope( mSelectionRectangle, &env );
if ( env.MinX != 0 || env.MinY != 0 || env.MaxX != 0 || env.MaxY != 0 ) //if envelope is invalid, skip the precise intersection test
{
selectionRect.set( env.MinX, env.MinY, env.MaxX, env.MaxY );
if ( !feature.geometry() || !feature.geometry()->intersects( selectionRect ) )
{
OGR_F_Destroy( fet );
continue;
}
}
}
// we have a feature, end this cycle
feature.setValid( true );
OGR_F_Destroy( fet );
return true;
} // while
QgsDebugMsg( "Feature is null" );
close();
return false;
}
