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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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SimplifyGeometries.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 (QgsMapToPixelSimplifier,
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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.parameters import ParameterNumber
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from processing.core.parameters import ParameterSelection
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from processing.core.outputs import OutputVector
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from processing.tools import dataobjects
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pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
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class SimplifyGeometries(QgisAlgorithm):
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INPUT = 'INPUT'
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TOLERANCE = 'TOLERANCE'
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OUTPUT = 'OUTPUT'
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METHOD = 'METHOD'
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def icon(self):
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return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'simplify.png'))
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def group(self):
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return self.tr('Vector geometry tools')
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def __init__(self):
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super().__init__()
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self.addParameter(ParameterVector(self.INPUT,
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self.tr('Input layer'),
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[dataobjects.TYPE_VECTOR_POLYGON, dataobjects.TYPE_VECTOR_LINE]))
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self.methods = [self.tr('Distance (Douglas-Peucker)'),
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'Snap to grid',
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'Area (Visvalingam)']
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self.addParameter(ParameterSelection(
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self.METHOD,
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self.tr('Simplification method'),
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self.methods, default=0))
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self.addParameter(ParameterNumber(self.TOLERANCE,
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self.tr('Tolerance'), 0.0, 10000000.0, 1.0))
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self.addOutput(OutputVector(self.OUTPUT, self.tr('Simplified')))
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def name(self):
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return 'simplifygeometries'
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def displayName(self):
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return self.tr('Simplify geometries')
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def processAlgorithm(self, parameters, context, feedback):
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layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)
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tolerance = self.getParameterValue(self.TOLERANCE)
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method = self.getParameterValue(self.METHOD)
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pointsBefore = 0
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pointsAfter = 0
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writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.fields(), layer.wkbType(),
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layer.crs(), context)
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features = QgsProcessingUtils.getFeatures(layer, context)
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total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
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if method != 0:
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simplifier = QgsMapToPixelSimplifier(QgsMapToPixelSimplifier.SimplifyGeometry, tolerance, method)
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for current, input_feature in enumerate(features):
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out_feature = input_feature
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if input_feature.geometry():
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input_geometry = input_feature.geometry()
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pointsBefore += input_geometry.geometry().nCoordinates()
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if method == 0: # distance
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output_geometry = input_geometry.simplify(tolerance)
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else:
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output_geometry = simplifier.simplify(input_geometry)
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pointsAfter += output_geometry.geometry().nCoordinates()
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out_feature.setGeometry(output_geometry)
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writer.addFeature(out_feature)
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feedback.setProgress(int(current * total))
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del writer
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QgsMessageLog.logMessage(self.tr('Simplify: Input geometries have been simplified from {0} to {1} points').format(pointsBefore, pointsAfter),
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self.tr('Processing'), QgsMessageLog.INFO)
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