@@ -60,77 +60,88 @@ def defineCharacteristics(self):
self .addOutput (OutputVector (Clip .OUTPUT , self .tr ('Clipped' )))
def processAlgorithm (self , progress ):
layerA = dataobjects .getObjectFromUri (
source_layer = dataobjects .getObjectFromUri (
self .getParameterValue (Clip .INPUT ))
layerB = dataobjects .getObjectFromUri (
mask_layer = dataobjects .getObjectFromUri (
self .getParameterValue (Clip .OVERLAY ))
writer = self .getOutputFromName (self .OUTPUT ).getVectorWriter (
layerA .pendingFields (),
layerA .dataProvider ().geometryType (),
layerA .dataProvider ().crs ())
inFeatA = QgsFeature ()
inFeatB = QgsFeature ()
outFeat = QgsFeature ()
index = vector .spatialindex (layerB )
selectionA = vector .features (layerA )
total = 100.0 / len (selectionA )
for current , inFeatA in enumerate (selectionA ):
geom = inFeatA .geometry ()
attrs = inFeatA .attributes ()
intersects = index .intersects (geom .boundingBox ())
first = True
found = False
if len (intersects ) > 0 :
for i in intersects :
layerB .getFeatures (
QgsFeatureRequest ().setFilterFid (i )).nextFeature (
inFeatB )
tmpGeom = inFeatB .geometry ()
if tmpGeom .intersects (geom ):
found = True
if first :
outFeat .setGeometry (QgsGeometry (tmpGeom ))
first = False
else :
cur_geom = outFeat .geometry ()
new_geom = QgsGeometry (cur_geom .combine (tmpGeom ))
if new_geom .isEmpty () or new_geom .isGeosEmpty () or not new_geom .isGeosValid ():
ProcessingLog .addToLog (ProcessingLog .LOG_ERROR ,
self .tr ('GEOS geoprocessing error: One or '
'more input features have invalid '
'geometry.' ))
break
outFeat .setGeometry (QgsGeometry (new_geom ))
if found :
cur_geom = outFeat .geometry ()
new_geom = QgsGeometry (geom .intersection (cur_geom ))
source_layer .fields (),
source_layer .dataProvider ().geometryType (),
source_layer .crs ())
# first build up a list of clip geometries
clip_geoms = []
for maskFeat in vector .features (mask_layer , QgsFeatureRequest ().setSubsetOfAttributes ([])):
clip_geoms .append (maskFeat .geometry ())
# are we clipping against a single feature? if so, we can show finer progress reports
if len (clip_geoms ) > 1 :
combined_clip_geom = QgsGeometry .unaryUnion (clip_geoms )
single_clip_feature = False
else :
combined_clip_geom = clip_geoms [0 ]
single_clip_feature = True
# use prepared geometries for faster intersection tests
engine = QgsGeometry .createGeometryEngine (combined_clip_geom .geometry ())
engine .prepareGeometry ()
tested_feature_ids = set ()
for i , clip_geom in enumerate (clip_geoms ):
input_features = [f for f in vector .features (source_layer , QgsFeatureRequest ().setFilterRect (clip_geom .boundingBox ()))]
if single_clip_feature :
total = 100.0 / len (input_features )
else :
total = 0
for current , in_feat in enumerate (input_features ):
if not in_feat .geometry ():
continue
if in_feat .id () in tested_feature_ids :
# don't retest a feature we have already checked
continue
tested_feature_ids .add (in_feat .id ())
if not engine .intersects (in_feat .geometry ().geometry ()):
continue
if not engine .contains (in_feat .geometry ().geometry ()):
cur_geom = in_feat .geometry ()
new_geom = combined_clip_geom .intersection (cur_geom )
if new_geom .wkbType () == Qgis .WKBUnknown or QgsWKBTypes .flatType (new_geom .geometry ().wkbType ()) == QgsWKBTypes .GeometryCollection :
int_com = QgsGeometry ( geom .combine (cur_geom ) )
int_sym = QgsGeometry ( geom .symDifference (cur_geom ) )
new_geom = QgsGeometry ( int_com .difference (int_sym ) )
int_com = in_feat . geometry () .combine (new_geom )
int_sym = in_feat . geometry () .symDifference (new_geom )
new_geom = int_com .difference (int_sym )
if new_geom .isGeosEmpty () or not new_geom .isGeosValid ():
ProcessingLog .addToLog (ProcessingLog .LOG_ERROR ,
self .tr ('GEOS geoprocessing error: One or more '
'input features have invalid geometry.' ))
continue
try :
outFeat .setGeometry (new_geom )
outFeat .setAttributes (attrs )
writer .addFeature (outFeat )
except :
ProcessingLog .addToLog (ProcessingLog .LOG_ERROR ,
self .tr ('Feature geometry error: One or more '
'output features ignored due to '
'invalid geometry.' ))
continue
progress .setPercentage (int (current * total ))
else :
# clip geometry totally contains feature geometry, so no need to perform intersection
new_geom = in_feat .geometry ()
try :
out_feat = QgsFeature ()
out_feat .setGeometry (new_geom )
out_feat .setAttributes (in_feat .attributes ())
writer .addFeature (out_feat )
except :
ProcessingLog .addToLog (ProcessingLog .LOG_ERROR ,
self .tr ('Feature geometry error: One or more '
'output features ignored due to '
'invalid geometry.' ))
continue
if single_clip_feature :
progress .setPercentage (int (current * total ))
if not single_clip_feature :
# coarse progress report for multiple clip geometries
progress .setPercentage (100.0 * i / len (clip_geoms ))
del writer
