# -*- coding: utf-8 -*- """ *************************************************************************** ShortestPathPointToLayer.py --------------------- Date : December 2016 Copyright : (C) 2016 by Alexander Bruy Email : alexander dot bruy 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__ = 'Alexander Bruy' __date__ = 'December 2016' __copyright__ = '(C) 2016, Alexander Bruy' # This will get replaced with a git SHA1 when you do a git archive __revision__ = '$Format:%H$' import os from collections import OrderedDict from qgis.PyQt.QtCore import QVariant from qgis.PyQt.QtGui import QIcon from qgis.core import (NULL, QgsWkbTypes, QgsUnitTypes, QgsFeature, QgsFeatureSink, QgsGeometry, QgsFeatureRequest, QgsField, QgsPointXY, QgsProcessing, QgsProcessingParameterEnum, QgsProcessingParameterPoint, QgsProcessingParameterField, QgsProcessingParameterNumber, QgsProcessingParameterString, QgsProcessingParameterFeatureSource, QgsProcessingParameterFeatureSink, QgsProcessingParameterDefinition) from qgis.analysis import (QgsVectorLayerDirector, QgsNetworkDistanceStrategy, QgsNetworkSpeedStrategy, QgsGraphBuilder, QgsGraphAnalyzer ) from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0] class ShortestPathPointToLayer(QgisAlgorithm): INPUT = 'INPUT' START_POINT = 'START_POINT' END_POINTS = 'END_POINTS' STRATEGY = 'STRATEGY' DIRECTION_FIELD = 'DIRECTION_FIELD' VALUE_FORWARD = 'VALUE_FORWARD' VALUE_BACKWARD = 'VALUE_BACKWARD' VALUE_BOTH = 'VALUE_BOTH' DEFAULT_DIRECTION = 'DEFAULT_DIRECTION' SPEED_FIELD = 'SPEED_FIELD' DEFAULT_SPEED = 'DEFAULT_SPEED' TOLERANCE = 'TOLERANCE' OUTPUT = 'OUTPUT' def icon(self): return QIcon(os.path.join(pluginPath, 'images', 'networkanalysis.svg')) def group(self): return self.tr('Network analysis') def groupId(self): return 'networkanalysis' def __init__(self): super().__init__() def initAlgorithm(self, config=None): self.DIRECTIONS = OrderedDict([ (self.tr('Forward direction'), QgsVectorLayerDirector.DirectionForward), (self.tr('Backward direction'), QgsVectorLayerDirector.DirectionBackward), (self.tr('Both directions'), QgsVectorLayerDirector.DirectionBoth)]) self.STRATEGIES = [self.tr('Shortest'), self.tr('Fastest') ] self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT, self.tr('Vector layer representing network'), [QgsProcessing.TypeVectorLine])) self.addParameter(QgsProcessingParameterPoint(self.START_POINT, self.tr('Start point'))) self.addParameter(QgsProcessingParameterFeatureSource(self.END_POINTS, self.tr('Vector layer with end points'), [QgsProcessing.TypeVectorPoint])) self.addParameter(QgsProcessingParameterEnum(self.STRATEGY, self.tr('Path type to calculate'), self.STRATEGIES, defaultValue=0)) params = [] params.append(QgsProcessingParameterField(self.DIRECTION_FIELD, self.tr('Direction field'), None, self.INPUT, optional=True)) params.append(QgsProcessingParameterString(self.VALUE_FORWARD, self.tr('Value for forward direction'), optional=True)) params.append(QgsProcessingParameterString(self.VALUE_BACKWARD, self.tr('Value for backward direction'), optional=True)) params.append(QgsProcessingParameterString(self.VALUE_BOTH, self.tr('Value for both directions'), optional=True)) params.append(QgsProcessingParameterEnum(self.DEFAULT_DIRECTION, self.tr('Default direction'), list(self.DIRECTIONS.keys()), defaultValue=2)) params.append(QgsProcessingParameterField(self.SPEED_FIELD, self.tr('Speed field'), None, self.INPUT, optional=True)) params.append(QgsProcessingParameterNumber(self.DEFAULT_SPEED, self.tr('Default speed (km/h)'), QgsProcessingParameterNumber.Double, 5.0, False, 0, 99999999.99)) params.append(QgsProcessingParameterNumber(self.TOLERANCE, self.tr('Topology tolerance'), QgsProcessingParameterNumber.Double, 0.0, False, 0, 99999999.99)) for p in params: p.setFlags(p.flags() | QgsProcessingParameterDefinition.FlagAdvanced) self.addParameter(p) self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Shortest path'), QgsProcessing.TypeVectorLine)) def name(self): return 'shortestpathpointtolayer' def displayName(self): return self.tr('Shortest path (point to layer)') def processAlgorithm(self, parameters, context, feedback): network = self.parameterAsSource(parameters, self.INPUT, context) startPoint = self.parameterAsPoint(parameters, self.START_POINT, context, network.sourceCrs()) endPoints = self.parameterAsSource(parameters, self.END_POINTS, context) strategy = self.parameterAsEnum(parameters, self.STRATEGY, context) directionFieldName = self.parameterAsString(parameters, self.DIRECTION_FIELD, context) forwardValue = self.parameterAsString(parameters, self.VALUE_FORWARD, context) backwardValue = self.parameterAsString(parameters, self.VALUE_BACKWARD, context) bothValue = self.parameterAsString(parameters, self.VALUE_BOTH, context) defaultDirection = self.parameterAsEnum(parameters, self.DEFAULT_DIRECTION, context) speedFieldName = self.parameterAsString(parameters, self.SPEED_FIELD, context) defaultSpeed = self.parameterAsDouble(parameters, self.DEFAULT_SPEED, context) tolerance = self.parameterAsDouble(parameters, self.TOLERANCE, context) fields = endPoints.fields() fields.append(QgsField('start', QVariant.String, '', 254, 0)) fields.append(QgsField('end', QVariant.String, '', 254, 0)) fields.append(QgsField('cost', QVariant.Double, '', 20, 7)) feat = QgsFeature() feat.setFields(fields) (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context, fields, QgsWkbTypes.LineString, network.sourceCrs()) directionField = -1 if directionFieldName: directionField = network.fields().lookupField(directionFieldName) speedField = -1 if speedFieldName: speedField = network.fields().lookupField(speedFieldName) director = QgsVectorLayerDirector(network, directionField, forwardValue, backwardValue, bothValue, defaultDirection) distUnit = context.project().crs().mapUnits() multiplier = QgsUnitTypes.fromUnitToUnitFactor(distUnit, QgsUnitTypes.DistanceMeters) if strategy == 0: strategy = QgsNetworkDistanceStrategy() else: strategy = QgsNetworkSpeedStrategy(speedField, defaultSpeed, multiplier * 1000.0 / 3600.0) multiplier = 3600 director.addStrategy(strategy) builder = QgsGraphBuilder(network.sourceCrs(), True, tolerance) feedback.pushInfo(self.tr('Loading end points...')) request = QgsFeatureRequest() request.setDestinationCrs(network.sourceCrs(), context.transformContext()) features = endPoints.getFeatures(request) total = 100.0 / endPoints.featureCount() if endPoints.featureCount() else 0 points = [startPoint] source_attributes = {} i = 1 for current, f in enumerate(features): if feedback.isCanceled(): break if not f.hasGeometry(): continue for p in f.geometry().vertices(): points.append(QgsPointXY(p)) source_attributes[i] = f.attributes() i += 1 feedback.setProgress(int(current * total)) feedback.pushInfo(self.tr('Building graph...')) snappedPoints = director.makeGraph(builder, points, feedback) feedback.pushInfo(self.tr('Calculating shortest paths...')) graph = builder.graph() idxStart = graph.findVertex(snappedPoints[0]) tree, costs = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0) nPoints = len(snappedPoints) total = 100.0 / nPoints if nPoints else 1 for i in range(1, nPoints): if feedback.isCanceled(): break idxEnd = graph.findVertex(snappedPoints[i]) if tree[idxEnd] == -1: msg = self.tr('There is no route from start point ({}) to end point ({}).'.format(startPoint.toString(), points[i].toString())) feedback.reportError(msg) # add feature with no geometry feat.clearGeometry() attrs = source_attributes[i] attrs.extend([NULL, points[i].toString()]) feat.setAttributes(attrs) sink.addFeature(feat, QgsFeatureSink.FastInsert) continue route = [graph.vertex(idxEnd).point()] cost = costs[idxEnd] current = idxEnd while current != idxStart: current = graph.edge(tree[current]).fromVertex() route.append(graph.vertex(current).point()) route.reverse() geom = QgsGeometry.fromPolylineXY(route) attrs = source_attributes[i] attrs.extend([startPoint.toString(), points[i].toString(), cost / multiplier]) feat.setAttributes(attrs) feat.setGeometry(geom) sink.addFeature(feat, QgsFeatureSink.FastInsert) feedback.setProgress(int(i * total)) return {self.OUTPUT: dest_id}