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| 1 | +/*************************************************************************** |
| 2 | + qgsalgorithmshortestpathpointtolayer.cpp |
| 3 | + --------------------- |
| 4 | + begin : July 2018 |
| 5 | + copyright : (C) 2018 by Alexander Bruy |
| 6 | + email : alexander dot bruy at gmail dot com |
| 7 | + ***************************************************************************/ |
| 8 | + |
| 9 | +/*************************************************************************** |
| 10 | + * * |
| 11 | + * This program is free software; you can redistribute it and/or modify * |
| 12 | + * it under the terms of the GNU General Public License as published by * |
| 13 | + * the Free Software Foundation; either version 2 of the License, or * |
| 14 | + * (at your option) any later version. * |
| 15 | + * * |
| 16 | + ***************************************************************************/ |
| 17 | + |
| 18 | +#include "qgsalgorithmshortestpathpointtolayer.h" |
| 19 | + |
| 20 | +#include "qgsgraphanalyzer.h" |
| 21 | + |
| 22 | +#include "qgsmessagelog.h" |
| 23 | + |
| 24 | +///@cond PRIVATE |
| 25 | + |
| 26 | +QString QgsShortestPathPointToLayerAlgorithm::name() const |
| 27 | +{ |
| 28 | + return QStringLiteral( "shortestpathpointtolayer" ); |
| 29 | +} |
| 30 | + |
| 31 | +QString QgsShortestPathPointToLayerAlgorithm::displayName() const |
| 32 | +{ |
| 33 | + return QObject::tr( "Shortest path (point to layer)" ); |
| 34 | +} |
| 35 | + |
| 36 | +QStringList QgsShortestPathPointToLayerAlgorithm::tags() const |
| 37 | +{ |
| 38 | + return QObject::tr( "network,path,shortest,fastest" ).split( ',' ); |
| 39 | +} |
| 40 | + |
| 41 | +QString QgsShortestPathPointToLayerAlgorithm::shortHelpString() const |
| 42 | +{ |
| 43 | + return QObject::tr( "This algorithm computes optimal (shortest or fastest) route between given start point and multiple end points defined by point vector layer." ); |
| 44 | +} |
| 45 | + |
| 46 | +QgsShortestPathPointToLayerAlgorithm *QgsShortestPathPointToLayerAlgorithm::createInstance() const |
| 47 | +{ |
| 48 | + return new QgsShortestPathPointToLayerAlgorithm(); |
| 49 | +} |
| 50 | + |
| 51 | +void QgsShortestPathPointToLayerAlgorithm::initAlgorithm( const QVariantMap & ) |
| 52 | +{ |
| 53 | + addCommonParams(); |
| 54 | + addParameter( new QgsProcessingParameterPoint( QStringLiteral( "START_POINT" ), QObject::tr( "Start point" ) ) ); |
| 55 | + addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "END_POINTS" ), QObject::tr( "Vector layer with end points" ), QList< int >() << QgsProcessing::TypeVectorPoint ) ); |
| 56 | + |
| 57 | + addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "OUTPUT" ), QObject::tr( "Shortest path" ), QgsProcessing::TypeVectorLine ) ); |
| 58 | +} |
| 59 | + |
| 60 | +QVariantMap QgsShortestPathPointToLayerAlgorithm::processAlgorithm( const QVariantMap ¶meters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) |
| 61 | +{ |
| 62 | + loadCommonParams( parameters, context, feedback ); |
| 63 | + |
| 64 | + QgsPointXY startPoint = parameterAsPoint( parameters, QStringLiteral( "START_POINT" ), context, mNetwork->sourceCrs() ); |
| 65 | + |
| 66 | + std::unique_ptr< QgsFeatureSource > endPoints( parameterAsSource( parameters, QStringLiteral( "END_POINTS" ), context ) ); |
| 67 | + if ( !endPoints ) |
| 68 | + throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "END_POINTS" ) ) ); |
| 69 | + |
| 70 | + QgsFields fields = endPoints->fields(); |
| 71 | + fields.append( QgsField( QStringLiteral( "start" ), QVariant::String ) ); |
| 72 | + fields.append( QgsField( QStringLiteral( "end" ), QVariant::String ) ); |
| 73 | + fields.append( QgsField( QStringLiteral( "cost" ), QVariant::Double ) ); |
| 74 | + |
| 75 | + QString dest; |
| 76 | + std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, fields, QgsWkbTypes::LineString, mNetwork->sourceCrs() ) ); |
| 77 | + if ( !sink ) |
| 78 | + throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) ); |
| 79 | + |
| 80 | + QVector< QgsPointXY > points; |
| 81 | + points.push_front( startPoint ); |
| 82 | + QHash< int, QgsAttributes > sourceAttributes; |
| 83 | + loadPoints( endPoints.get(), points, sourceAttributes, context, feedback ); |
| 84 | + |
| 85 | + feedback->pushInfo( QObject::tr( "Building graph…" ) ); |
| 86 | + QVector< QgsPointXY > snappedPoints; |
| 87 | + mDirector->makeGraph( mBuilder.get(), points, snappedPoints, feedback ); |
| 88 | + |
| 89 | + feedback->pushInfo( QObject::tr( "Calculating shortest paths…" ) ); |
| 90 | + QgsGraph *graph = mBuilder->graph(); |
| 91 | + int idxStart = graph->findVertex( snappedPoints[0] ); |
| 92 | + int idxEnd; |
| 93 | + |
| 94 | + QVector< int > tree; |
| 95 | + QVector< double > costs; |
| 96 | + QgsGraphAnalyzer::dijkstra( graph, idxStart, 0, &tree, &costs ); |
| 97 | + |
| 98 | + QVector<QgsPointXY> route; |
| 99 | + double cost; |
| 100 | + |
| 101 | + QgsFeature feat; |
| 102 | + feat.setFields( fields ); |
| 103 | + QgsAttributes attributes; |
| 104 | + |
| 105 | + int step = points.size() > 0 ? 100.0 / points.size() : 1; |
| 106 | + for ( int i = 1; i < points.size(); i++ ) |
| 107 | + { |
| 108 | + if ( feedback->isCanceled() ) |
| 109 | + { |
| 110 | + break; |
| 111 | + } |
| 112 | + |
| 113 | + idxEnd = graph->findVertex( snappedPoints[i] ); |
| 114 | + if ( tree.at( idxEnd ) == -1 ) |
| 115 | + { |
| 116 | + feedback->reportError( QObject::tr( "There is no route from start point (%1) to end point (%2)." ) |
| 117 | + .arg( startPoint.toString() ) |
| 118 | + .arg( points[i].toString() ) ); |
| 119 | + feat.clearGeometry(); |
| 120 | + attributes = sourceAttributes.value( i ); |
| 121 | + attributes.append( QVariant() ); |
| 122 | + attributes.append( points[i].toString() ); |
| 123 | + feat.setAttributes( attributes ); |
| 124 | + sink->addFeature( feat, QgsFeatureSink::FastInsert ); |
| 125 | + continue; |
| 126 | + } |
| 127 | + |
| 128 | + route.clear(); |
| 129 | + route.push_front( graph->vertex( idxEnd ).point() ); |
| 130 | + cost = costs.at( idxEnd ); |
| 131 | + while ( idxEnd != idxStart ) |
| 132 | + { |
| 133 | + idxEnd = graph->edge( tree.at( idxEnd ) ).fromVertex(); |
| 134 | + route.push_front( graph->vertex( idxEnd ).point() ); |
| 135 | + } |
| 136 | + |
| 137 | + QgsGeometry geom = QgsGeometry::fromPolylineXY( route ); |
| 138 | + QgsFeature feat; |
| 139 | + feat.setFields( fields ); |
| 140 | + attributes = sourceAttributes.value( i ); |
| 141 | + attributes.append( startPoint.toString() ); |
| 142 | + attributes.append( points[i].toString() ); |
| 143 | + attributes.append( cost / mMultiplier ); |
| 144 | + feat.setAttributes( attributes ); |
| 145 | + feat.setGeometry( geom ); |
| 146 | + sink->addFeature( feat, QgsFeatureSink::FastInsert ); |
| 147 | + |
| 148 | + feedback->setProgress( i * step ); |
| 149 | + } |
| 150 | + |
| 151 | + QVariantMap outputs; |
| 152 | + outputs.insert( QStringLiteral( "OUTPUT" ), dest ); |
| 153 | + return outputs; |
| 154 | +} |
| 155 | + |
| 156 | +///@endcond |
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