# -*- coding: utf-8 -*- """ *************************************************************************** SimplifyGeometries.py --------------------- Date : August 2012 Copyright : (C) 2012 by Victor Olaya Email : volayaf at gmail dot com *************************************************************************** * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation; either version 2 of the License, or * * (at your option) any later version. * * * *************************************************************************** """ __author__ = 'Victor Olaya' __date__ = 'August 2012' __copyright__ = '(C) 2012, Victor Olaya' # This will get replaced with a git SHA1 when you do a git archive __revision__ = '$Format:%H$' import os from qgis.PyQt.QtGui import QIcon from qgis.core import Qgis, QgsFeature, QgsGeometry from processing.core.GeoAlgorithm import GeoAlgorithm from processing.core.ProcessingLog import ProcessingLog from processing.core.parameters import ParameterVector from processing.core.parameters import ParameterNumber from processing.core.outputs import OutputVector from processing.tools import dataobjects, vector pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0] class SimplifyGeometries(GeoAlgorithm): INPUT = 'INPUT' TOLERANCE = 'TOLERANCE' OUTPUT = 'OUTPUT' def getIcon(self): return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'simplify.png')) def defineCharacteristics(self): self.name, self.i18n_name = self.trAlgorithm('Simplify geometries') self.group, self.i18n_group = self.trAlgorithm('Vector geometry tools') self.addParameter(ParameterVector(self.INPUT, self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_POLYGON, ParameterVector.VECTOR_TYPE_LINE])) self.addParameter(ParameterNumber(self.TOLERANCE, self.tr('Tolerance'), 0.0, 10000000.0, 1.0)) self.addOutput(OutputVector(self.OUTPUT, self.tr('Simplified'))) def processAlgorithm(self, progress): layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT)) tolerance = self.getParameterValue(self.TOLERANCE) pointsBefore = 0 pointsAfter = 0 writer = self.getOutputFromName(self.OUTPUT).getVectorWriter( layer.pendingFields().toList(), layer.wkbType(), layer.crs()) features = vector.features(layer) total = 100.0 / len(features) for current, f in enumerate(features): featGeometry = f.geometry() attrs = f.attributes() pointsBefore += self.geomVertexCount(featGeometry) newGeometry = featGeometry.simplify(tolerance) pointsAfter += self.geomVertexCount(newGeometry) feature = QgsFeature() feature.setGeometry(newGeometry) feature.setAttributes(attrs) writer.addFeature(feature) progress.setPercentage(int(current * total)) del writer ProcessingLog.addToLog(ProcessingLog.LOG_INFO, self.tr('Simplify: Input geometries have been simplified from %s to %s points' % (pointsBefore, pointsAfter))) def geomVertexCount(self, geometry): geomType = geometry.type() if geomType == Qgis.Line: if geometry.isMultipart(): pointsList = geometry.asMultiPolyline() points = sum(pointsList, []) else: points = geometry.asPolyline() return len(points) elif geomType == Qgis.Polygon: if geometry.isMultipart(): polylinesList = geometry.asMultiPolygon() polylines = sum(polylinesList, []) else: polylines = geometry.asPolygon() points = [] for l in polylines: points.extend(l) return len(points) else: return None