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1e13d733c2
initAlgorithm() method This allows 2 benefits: - algorithms can be subclassed and have subclasses add additional parameters/outputs to the algorithm. With the previous approach of declaring parameters/outputs in the constructor, it's not possible to call virtual methods to add additional parameters/ outputs (since you can't call virtual methods from a constructor). - initAlgorithm takes a variant map argument, allowing the algorithm to dynamically adjust its declared parameters and outputs according to this configuration map. This potentially allows model algorithms which can be configured to have variable numbers of parameters and outputs at run time. E.g. a "router" algorithm which directs features to one of any number of output sinks depending on some user configured criteria.
203 lines
8.2 KiB
Python
203 lines
8.2 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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SplitWithLines.py
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---------------------
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Date : November 2014
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Revised : November 2016
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Copyright : (C) 2014 by Bernhard Ströbl
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Email : bernhard dot stroebl at jena dot de
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************
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"""
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__author__ = 'Bernhard Ströbl'
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__date__ = 'November 2014'
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__copyright__ = '(C) 2014, Bernhard Ströbl'
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# This will get replaced with a git SHA1 when you do a git archive
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__revision__ = '$Format:%H$'
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from qgis.core import (QgsApplication,
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QgsFeatureRequest,
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QgsFeature,
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QgsFeatureSink,
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QgsGeometry,
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QgsSpatialIndex,
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QgsWkbTypes,
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QgsMessageLog,
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QgsProcessingUtils)
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from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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from processing.core.parameters import ParameterVector
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from processing.core.outputs import OutputVector
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from processing.tools import dataobjects
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from processing.tools import vector
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class SplitWithLines(QgisAlgorithm):
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INPUT_A = 'INPUT_A'
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INPUT_B = 'INPUT_B'
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OUTPUT = 'OUTPUT'
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def group(self):
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return self.tr('Vector overlay tools')
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def __init__(self):
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super().__init__()
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def initAlgorithm(self, config=None):
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self.addParameter(ParameterVector(self.INPUT_A,
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self.tr('Input layer, single geometries only'), [dataobjects.TYPE_VECTOR_POLYGON,
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dataobjects.TYPE_VECTOR_LINE]))
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self.addParameter(ParameterVector(self.INPUT_B,
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self.tr('Split layer'), [dataobjects.TYPE_VECTOR_LINE]))
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self.addOutput(OutputVector(self.OUTPUT, self.tr('Split')))
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def name(self):
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return 'splitwithlines'
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def displayName(self):
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return self.tr('Split with lines')
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def processAlgorithm(self, parameters, context, feedback):
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layerA = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_A), context)
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splitLayer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_B), context)
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sameLayer = self.getParameterValue(self.INPUT_A) == self.getParameterValue(self.INPUT_B)
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fieldList = layerA.fields()
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writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fieldList, QgsWkbTypes.multiType(layerA.wkbType()),
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layerA.crs(), context)
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spatialIndex = QgsSpatialIndex()
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splitGeoms = {}
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request = QgsFeatureRequest()
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request.setSubsetOfAttributes([])
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for aSplitFeature in QgsProcessingUtils.getFeatures(splitLayer, context, request):
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splitGeoms[aSplitFeature.id()] = aSplitFeature.geometry()
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spatialIndex.insertFeature(aSplitFeature)
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# honor the case that user has selection on split layer and has setting "use selection"
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outFeat = QgsFeature()
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features = QgsProcessingUtils.getFeatures(layerA, context)
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if QgsProcessingUtils.featureCount(layerA, context) == 0:
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total = 100
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else:
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total = 100.0 / layerA.featureCount() if layerA.featureCount() else 0
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for current, inFeatA in enumerate(features):
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inGeom = inFeatA.geometry()
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attrsA = inFeatA.attributes()
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outFeat.setAttributes(attrsA)
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if inGeom.isMultipart():
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inGeoms = []
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for g in inGeom.asGeometryCollection():
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inGeoms.append(g)
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else:
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inGeoms = [inGeom]
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lines = spatialIndex.intersects(inGeom.boundingBox())
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if len(lines) > 0: # has intersection of bounding boxes
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splittingLines = []
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engine = QgsGeometry.createGeometryEngine(inGeom.geometry())
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engine.prepareGeometry()
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for i in lines:
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try:
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splitGeom = splitGeoms[i]
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except:
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continue
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# check if trying to self-intersect
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if sameLayer:
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if inFeatA.id() == i:
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continue
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if engine.intersects(splitGeom.geometry()):
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splittingLines.append(splitGeom)
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if len(splittingLines) > 0:
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for splitGeom in splittingLines:
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splitterPList = None
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outGeoms = []
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split_geom_engine = QgsGeometry.createGeometryEngine(splitGeom.geometry())
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split_geom_engine.prepareGeometry()
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while len(inGeoms) > 0:
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inGeom = inGeoms.pop()
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if inGeom.isNull(): # this has been encountered and created a run-time error
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continue
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if split_geom_engine.intersects(inGeom.geometry()):
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inPoints = vector.extractPoints(inGeom)
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if splitterPList is None:
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splitterPList = vector.extractPoints(splitGeom)
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try:
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result, newGeometries, topoTestPoints = inGeom.splitGeometry(splitterPList, False)
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except:
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QgsMessageLog.logMessage(self.tr('Geometry exception while splitting'), self.tr('Processing'), QgsMessageLog.WARNING)
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result = 1
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# splitGeometry: If there are several intersections
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# between geometry and splitLine, only the first one is considered.
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if result == 0: # split occurred
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if inPoints == vector.extractPoints(inGeom):
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# bug in splitGeometry: sometimes it returns 0 but
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# the geometry is unchanged
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outGeoms.append(inGeom)
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else:
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inGeoms.append(inGeom)
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for aNewGeom in newGeometries:
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inGeoms.append(aNewGeom)
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else:
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outGeoms.append(inGeom)
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else:
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outGeoms.append(inGeom)
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inGeoms = outGeoms
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parts = []
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for aGeom in inGeoms:
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passed = True
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if QgsWkbTypes.geometryType(aGeom.wkbType()) == QgsWkbTypes.LineGeometry:
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numPoints = aGeom.geometry().numPoints()
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if numPoints <= 2:
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if numPoints == 2:
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passed = not aGeom.geometry().isClosed() # tests if vertex 0 = vertex 1
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else:
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passed = False
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# sometimes splitting results in lines of zero length
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if passed:
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parts.append(aGeom)
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if len(parts) > 0:
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outFeat.setGeometry(QgsGeometry.collectGeometry(parts))
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writer.addFeature(outFeat, QgsFeatureSink.FastInsert)
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feedback.setProgress(int(current * total))
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del writer
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