# -*- 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 (QgsWkbTypes, QgsUnitTypes, QgsFeatureSink, QgsFeature, QgsGeometry, QgsPointXY, QgsFields, QgsField, QgsFeatureRequest, QgsMessageLog, QgsProcessingParameterDefinition, QgsProcessingUtils) from qgis.analysis import (QgsVectorLayerDirector, QgsNetworkDistanceStrategy, QgsNetworkSpeedStrategy, QgsGraphBuilder, QgsGraphAnalyzer ) from qgis.utils import iface from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm from processing.core.parameters import (ParameterVector, ParameterPoint, ParameterNumber, ParameterString, ParameterTableField, ParameterSelection ) from processing.core.outputs import OutputVector from processing.tools import dataobjects pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0] class ShortestPathPointToLayer(QgisAlgorithm): INPUT_VECTOR = 'INPUT_VECTOR' 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_LAYER = 'OUTPUT_LAYER' def icon(self): return QIcon(os.path.join(pluginPath, 'images', 'networkanalysis.svg')) def group(self): return self.tr('Network analysis') def __init__(self): super().__init__() self.DIRECTIONS = OrderedDict([ (self.tr('Forward direction'), QgsVectorLayerDirector.DirectionForward), (self.tr('Backward direction'), QgsVectorLayerDirector.DirectionForward), (self.tr('Both directions'), QgsVectorLayerDirector.DirectionForward)]) self.STRATEGIES = [self.tr('Shortest'), self.tr('Fastest') ] self.addParameter(ParameterVector(self.INPUT_VECTOR, self.tr('Vector layer representing network'), [dataobjects.TYPE_VECTOR_LINE])) self.addParameter(ParameterPoint(self.START_POINT, self.tr('Start point'))) self.addParameter(ParameterVector(self.END_POINTS, self.tr('Vector layer with end points'), [dataobjects.TYPE_VECTOR_POINT])) self.addParameter(ParameterSelection(self.STRATEGY, self.tr('Path type to calculate'), self.STRATEGIES, default=0)) params = [] params.append(ParameterTableField(self.DIRECTION_FIELD, self.tr('Direction field'), self.INPUT_VECTOR, optional=True)) params.append(ParameterString(self.VALUE_FORWARD, self.tr('Value for forward direction'), '', optional=True)) params.append(ParameterString(self.VALUE_BACKWARD, self.tr('Value for backward direction'), '', optional=True)) params.append(ParameterString(self.VALUE_BOTH, self.tr('Value for both directions'), '', optional=True)) params.append(ParameterSelection(self.DEFAULT_DIRECTION, self.tr('Default direction'), list(self.DIRECTIONS.keys()), default=2)) params.append(ParameterTableField(self.SPEED_FIELD, self.tr('Speed field'), self.INPUT_VECTOR, optional=True)) params.append(ParameterNumber(self.DEFAULT_SPEED, self.tr('Default speed (km/h)'), 0.0, 99999999.999999, 5.0)) params.append(ParameterNumber(self.TOLERANCE, self.tr('Topology tolerance'), 0.0, 99999999.999999, 0.0)) for p in params: p.setFlags(p.flags() | QgsProcessingParameterDefinition.FlagAdvanced) self.addParameter(p) self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Shortest path'), datatype=[dataobjects.TYPE_VECTOR_LINE])) def name(self): return 'shortestpathpointtolayer' def displayName(self): return self.tr('Shortest path (point to layer)') def processAlgorithm(self, parameters, context, feedback): layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_VECTOR), context) startPoint = self.getParameterValue(self.START_POINT) endPoints = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.END_POINTS), context) strategy = self.getParameterValue(self.STRATEGY) directionFieldName = self.getParameterValue(self.DIRECTION_FIELD) forwardValue = self.getParameterValue(self.VALUE_FORWARD) backwardValue = self.getParameterValue(self.VALUE_BACKWARD) bothValue = self.getParameterValue(self.VALUE_BOTH) defaultDirection = self.getParameterValue(self.DEFAULT_DIRECTION) bothValue = self.getParameterValue(self.VALUE_BOTH) defaultDirection = self.getParameterValue(self.DEFAULT_DIRECTION) speedFieldName = self.getParameterValue(self.SPEED_FIELD) defaultSpeed = self.getParameterValue(self.DEFAULT_SPEED) tolerance = self.getParameterValue(self.TOLERANCE) fields = QgsFields() 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) writer = self.getOutputFromName( self.OUTPUT_LAYER).getVectorWriter(fields, QgsWkbTypes.LineString, layer.crs(), context) tmp = startPoint.split(',') startPoint = QgsPointXY(float(tmp[0]), float(tmp[1])) directionField = -1 if directionFieldName is not None: directionField = layer.fields().lookupField(directionFieldName) speedField = -1 if speedFieldName is not None: speedField = layer.fields().lookupField(speedFieldName) director = QgsVectorLayerDirector(layer, directionField, forwardValue, backwardValue, bothValue, defaultDirection) distUnit = iface.mapCanvas().mapSettings().destinationCrs().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(iface.mapCanvas().mapSettings().destinationCrs(), True, tolerance) feedback.pushInfo(self.tr('Loading end points...')) request = QgsFeatureRequest() request.setFlags(request.flags() ^ QgsFeatureRequest.SubsetOfAttributes) features = QgsProcessingUtils.getFeatures(endPoints, context, request) count = QgsProcessingUtils.featureCount(endPoints, context) points = [startPoint] for f in features: points.append(f.geometry().asPoint()) feedback.pushInfo(self.tr('Building graph...')) snappedPoints = director.makeGraph(builder, points) feedback.pushInfo(self.tr('Calculating shortest paths...')) graph = builder.graph() idxStart = graph.findVertex(snappedPoints[0]) tree, cost = QgsGraphAnalyzer.dijkstra(graph, idxStart, 0) route = [] total = 100.0 / count if count else 1 for i in range(1, count + 1): 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.setProgressText(msg) QgsMessageLog.logMessage(msg, self.tr('Processing'), QgsMessageLog.WARNING) continue cost = 0.0 current = idxEnd while current != idxStart: cost += graph.edge(tree[current]).cost(0) route.append(graph.vertex(graph.edge(tree[current]).inVertex()).point()) current = graph.edge(tree[current]).outVertex() route.append(snappedPoints[0]) route.reverse() geom = QgsGeometry.fromPolyline(route) feat.setGeometry(geom) feat['start'] = startPoint.toString() feat['end'] = points[i].toString() feat['cost'] = cost / multiplier writer.addFeature(feat, QgsFeatureSink.FastInsert) route[:] = [] feedback.setProgress(int(i * total)) del writer