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119 lines
4.6 KiB
Python
119 lines
4.6 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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SingleSidedBuffer.py
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--------------------
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Date : August 2016
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Copyright : (C) 2016 by Nyall Dawson
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Email : nyall dot dawson 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__ = 'Nyall Dawson'
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__date__ = 'August 2016'
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__copyright__ = '(C) 2016, Nyall Dawson'
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# This will get replaced with a git SHA1 when you do a git archive323
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__revision__ = '$Format:%H$'
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import os
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from qgis.core import QgsGeometry, QgsWkbTypes
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from processing.core.GeoAlgorithm import GeoAlgorithm
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from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
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from processing.core.parameters import ParameterVector, ParameterSelection, ParameterNumber
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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 SingleSidedBuffer(GeoAlgorithm):
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INPUT_LAYER = 'INPUT_LAYER'
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OUTPUT_LAYER = 'OUTPUT_LAYER'
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DISTANCE = 'DISTANCE'
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SIDE = 'SIDE'
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SEGMENTS = 'SEGMENTS'
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JOIN_STYLE = 'JOIN_STYLE'
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MITRE_LIMIT = 'MITRE_LIMIT'
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def defineCharacteristics(self):
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self.name, self.i18n_name = self.trAlgorithm('Single sided buffer')
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self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools')
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self.addParameter(ParameterVector(self.INPUT_LAYER,
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self.tr('Input layer'), [dataobjects.TYPE_VECTOR_LINE]))
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self.addParameter(ParameterNumber(self.DISTANCE,
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self.tr('Distance'), default=10.0))
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self.sides = [self.tr('Left'),
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'Right']
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self.addParameter(ParameterSelection(
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self.SIDE,
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self.tr('Side'),
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self.sides))
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self.addParameter(ParameterNumber(self.SEGMENTS,
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self.tr('Segments'), 1, default=8))
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self.join_styles = [self.tr('Round'),
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'Mitre',
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'Bevel']
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self.addParameter(ParameterSelection(
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self.JOIN_STYLE,
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self.tr('Join style'),
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self.join_styles))
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self.addParameter(ParameterNumber(self.MITRE_LIMIT,
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self.tr('Mitre limit'), 1, default=2))
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self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Single sided buffers')))
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def processAlgorithm(self, progress):
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layer = dataobjects.getObjectFromUri(
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self.getParameterValue(self.INPUT_LAYER))
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writer = self.getOutputFromName(
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self.OUTPUT_LAYER).getVectorWriter(
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layer.fields().toList(),
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QgsWkbTypes.Polygon,
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layer.crs())
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distance = self.getParameterValue(self.DISTANCE)
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segments = int(self.getParameterValue(self.SEGMENTS))
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join_style = self.getParameterValue(self.JOIN_STYLE) + 1
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if self.getParameterValue(self.SIDE) == 0:
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side = QgsGeometry.SideLeft
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else:
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side = QgsGeometry.SideRight
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miter_limit = self.getParameterValue(self.MITRE_LIMIT)
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features = vector.features(layer)
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total = 100.0 / len(features)
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for current, input_feature in enumerate(features):
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output_feature = input_feature
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input_geometry = input_feature.geometry()
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if input_geometry:
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output_geometry = input_geometry.singleSidedBuffer(distance, segments,
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side, join_style, miter_limit)
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if not output_geometry:
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raise GeoAlgorithmExecutionException(
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self.tr('Error calculating single sided buffer'))
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output_feature.setGeometry(output_geometry)
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writer.addFeature(output_feature)
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progress.setPercentage(int(current * total))
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del writer
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