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156 lines
6.7 KiB
Python
156 lines
6.7 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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Clip.py
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---------------------
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Date : August 2012
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Copyright : (C) 2012 by Victor Olaya
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Email : volayaf at gmail dot com
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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__ = 'Victor Olaya'
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__date__ = 'August 2012'
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__copyright__ = '(C) 2012, Victor Olaya'
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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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import os
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from qgis.PyQt.QtGui import QIcon
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from qgis.core import Qgis, QgsFeature, QgsGeometry, QgsFeatureRequest, QgsWkbTypes, QgsWkbTypes
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.ProcessingLog import ProcessingLog
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from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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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, vector
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pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
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class Clip(GeoAlgorithm):
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INPUT = 'INPUT'
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OVERLAY = 'OVERLAY'
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OUTPUT = 'OUTPUT'
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def getIcon(self):
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return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'clip.png'))
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def defineCharacteristics(self):
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self.name, self.i18n_name = self.trAlgorithm('Clip')
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self.group, self.i18n_group = self.trAlgorithm('Vector overlay tools')
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self.addParameter(ParameterVector(Clip.INPUT,
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self.tr('Input layer')))
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self.addParameter(ParameterVector(Clip.OVERLAY,
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self.tr('Clip layer'), [dataobjects.TYPE_VECTOR_POLYGON]))
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self.addOutput(OutputVector(Clip.OUTPUT, self.tr('Clipped')))
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def processAlgorithm(self, progress):
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source_layer = dataobjects.getObjectFromUri(
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self.getParameterValue(Clip.INPUT))
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mask_layer = dataobjects.getObjectFromUri(
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self.getParameterValue(Clip.OVERLAY))
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writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
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source_layer.fields(),
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QgsWkbTypes.multiType(source_layer.wkbType()),
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source_layer.crs())
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# first build up a list of clip geometries
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clip_geoms = []
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for maskFeat in vector.features(mask_layer, QgsFeatureRequest().setSubsetOfAttributes([])):
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clip_geoms.append(maskFeat.geometry())
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# are we clipping against a single feature? if so, we can show finer progress reports
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if len(clip_geoms) > 1:
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combined_clip_geom = QgsGeometry.unaryUnion(clip_geoms)
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single_clip_feature = False
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else:
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combined_clip_geom = clip_geoms[0]
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single_clip_feature = True
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# use prepared geometries for faster intersection tests
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engine = QgsGeometry.createGeometryEngine(combined_clip_geom.geometry())
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engine.prepareGeometry()
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tested_feature_ids = set()
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for i, clip_geom in enumerate(clip_geoms):
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input_features = [f for f in vector.features(source_layer, QgsFeatureRequest().setFilterRect(clip_geom.boundingBox()))]
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if not input_features:
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continue
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if single_clip_feature:
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total = 100.0 / len(input_features)
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else:
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total = 0
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for current, in_feat in enumerate(input_features):
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if not in_feat.geometry():
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continue
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if in_feat.id() in tested_feature_ids:
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# don't retest a feature we have already checked
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continue
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tested_feature_ids.add(in_feat.id())
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if not engine.intersects(in_feat.geometry().geometry()):
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continue
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if not engine.contains(in_feat.geometry().geometry()):
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cur_geom = in_feat.geometry()
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new_geom = combined_clip_geom.intersection(cur_geom)
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if new_geom.wkbType() == QgsWkbTypes.Unknown or QgsWkbTypes.flatType(new_geom.geometry().wkbType()) == QgsWkbTypes.GeometryCollection:
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int_com = in_feat.geometry().combine(new_geom)
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int_sym = in_feat.geometry().symDifference(new_geom)
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if not int_com or not int_sym:
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ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
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self.tr('GEOS geoprocessing error: One or more '
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'input features have invalid geometry.'))
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else:
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new_geom = int_com.difference(int_sym)
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if new_geom.isGeosEmpty() or not new_geom.isGeosValid():
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ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
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self.tr('GEOS geoprocessing error: One or more '
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'input features have invalid geometry.'))
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else:
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# clip geometry totally contains feature geometry, so no need to perform intersection
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new_geom = in_feat.geometry()
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try:
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out_feat = QgsFeature()
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out_feat.setGeometry(new_geom)
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out_feat.setAttributes(in_feat.attributes())
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writer.addFeature(out_feat)
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except:
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ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
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self.tr('Feature geometry error: One or more '
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'output features ignored due to '
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'invalid geometry.'))
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continue
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if single_clip_feature:
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progress.setPercentage(int(current * total))
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if not single_clip_feature:
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# coarse progress report for multiple clip geometries
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progress.setPercentage(100.0 * i / len(clip_geoms))
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del writer
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