def _vertex_id(part, ring, vertex):
vertex_id = QgsVertexId(part, ring, vertex, QgsVertexId.SegmentVertex)
if not vertex_id.isValid():
vertex_id = QgsVertexId(part, ring, vertex,
QgsVertexId.CurveVertex)
if not vertex_id.isValid():
raise ValueError("Invalid vertex addressing.")
return vertex_id
def transformFeatures(self):
inQueue = multiprocessing.Queue()
outQueue = multiprocessing.Queue()
threads = []
numThreads = multiprocessing.cpu_count() + 1
for _ in range(numThreads):
p = multiprocessing.Process(target=transformPoint,
args=(self.metaFeatures,
self.reductionFactor, inQueue,
outQueue))
p.start()
threads.append(p)
features = \
{feature.id(): feature.geometry()
for feature in self.layer.getFeatures()}
for featureId in features:
abstractGeometry = features[featureId].constGet()
for p in range(abstractGeometry.partCount()):
for r in range(abstractGeometry.ringCount(p)):
for v in range(abstractGeometry.vertexCount(p, r) - 1):
# -1 because the last one is the first one again
vertexId = \
QgsVertexId(p, r, v, QgsVertexId.SegmentVertex)
if not vertexId.isValid():
vertexId = QgsVertexId(p, r, v,
QgsVertexId.CurveVertex)
if not vertexId.isValid():
continue
point = abstractGeometry.vertexAt(vertexId)
inQueue.put(
((featureId, p, r, v), (point.x(), point.y())))
self.progress.emit(1)
for _ in range(numThreads):
inQueue.put((None, (None, None)))
while True:
if self.stopped:
# clean inQueue
while True:
(f, g) = inQueue.get()
if f is None:
break
# put some more death pills so everybody gets one
for i in range(numThreads):
inQueue.put((None, (None, None)))
# wait for the children to die
for p in threads:
p.join()
# give up ourselves (main thread)
break
((featureId, p, r, v), (x, y)) = outQueue.get()
if featureId is None:
numThreads -= 1
if numThreads == 0:
break
else:
continue
abstractGeometry = features[featureId].constGet().clone()
abstractGeometry.moveVertex(
QgsVertexId(p, r, v, QgsVertexId.SegmentVertex),
QgsPoint(x, y))
features[featureId] = QgsGeometry(abstractGeometry)
self.layer.dataProvider().changeGeometryValues(features)
self.layer.reload()
