[processing] port shortest path (layer to point) alg to c++

qgis · Jul 30, 2018 · 72d13ac · 72d13ac
1 parent d999923
commit 72d13ac
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Showing 6 changed files with 217 additions and 3 deletions.
diff --git a/python/plugins/processing/algs/qgis/QgisAlgorithmProvider.py b/python/plugins/processing/algs/qgis/QgisAlgorithmProvider.py
@@ -125,7 +125,7 @@
 from .SetRasterStyle import SetRasterStyle
 from .SetVectorStyle import SetVectorStyle
 from .SetZValue import SetZValue
-from .ShortestPathLayerToPoint import ShortestPathLayerToPoint
+#from .ShortestPathLayerToPoint import ShortestPathLayerToPoint
 #from .ShortestPathPointToLayer import ShortestPathPointToLayer
 #from .ShortestPathPointToPoint import ShortestPathPointToPoint
 from .SingleSidedBuffer import SingleSidedBuffer
@@ -239,7 +239,7 @@ def getAlgs(self):
                 SetRasterStyle(),
                 SetVectorStyle(),
                 SetZValue(),
-                ShortestPathLayerToPoint(),
+                #ShortestPathLayerToPoint(),
                 #ShortestPathPointToLayer(),
                 #ShortestPathPointToPoint(),
                 SingleSidedBuffer(),

diff --git a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@@ -3036,7 +3036,7 @@ tests:
             start: skip
             end: skip
 
-  - algorithm: qgis:shortestpathlayertopoint
+  - algorithm: native:shortestpathlayertopoint
     name: Shortest path layer to point
     params:
       DEFAULT_DIRECTION: 2

diff --git a/src/analysis/CMakeLists.txt b/src/analysis/CMakeLists.txt
@@ -77,6 +77,7 @@ SET(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmrotate.cpp
   processing/qgsalgorithmsaveselectedfeatures.cpp
   processing/qgsalgorithmsegmentize.cpp
+  processing/qgsalgorithmshortestpathlayertopoint.cpp
   processing/qgsalgorithmshortestpathpointtolayer.cpp
   processing/qgsalgorithmshortestpathpointtopoint.cpp
   processing/qgsalgorithmsimplify.cpp

diff --git a/src/analysis/processing/qgsalgorithmshortestpathlayertopoint.cpp b/src/analysis/processing/qgsalgorithmshortestpathlayertopoint.cpp
@@ -0,0 +1,158 @@
+/***************************************************************************
+                         qgsalgorithmshortestpathlayertopoint.cpp
+                         ---------------------
+    begin                : July 2018
+    copyright            : (C) 2018 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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsalgorithmshortestpathlayertopoint.h"
+
+#include "qgsgraphanalyzer.h"
+
+#include "qgsmessagelog.h"
+
+///@cond PRIVATE
+
+QString QgsShortestPathLayerToPointAlgorithm::name() const
+{
+  return QStringLiteral( "shortestpathlayertopoint" );
+}
+
+QString QgsShortestPathLayerToPointAlgorithm::displayName() const
+{
+  return QObject::tr( "Shortest path (layer to point)" );
+}
+
+QStringList QgsShortestPathLayerToPointAlgorithm::tags() const
+{
+  return QObject::tr( "network,path,shortest,fastest" ).split( ',' );
+}
+
+QString QgsShortestPathLayerToPointAlgorithm::shortHelpString() const
+{
+  return QObject::tr( "This algorithm computes optimal (shortest or fastest) route from multiple start points defined by vector layer and given end point." );
+}
+
+QgsShortestPathLayerToPointAlgorithm *QgsShortestPathLayerToPointAlgorithm::createInstance() const
+{
+  return new QgsShortestPathLayerToPointAlgorithm();
+}
+
+void QgsShortestPathLayerToPointAlgorithm::initAlgorithm( const QVariantMap & )
+{
+  addCommonParams();
+  addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "START_POINTS" ), QObject::tr( "Vector layer with start points" ), QList< int >() << QgsProcessing::TypeVectorPoint ) );
+  addParameter( new QgsProcessingParameterPoint( QStringLiteral( "END_POINT" ), QObject::tr( "End point" ) ) );
+
+  addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "OUTPUT" ), QObject::tr( "Shortest path" ), QgsProcessing::TypeVectorLine ) );
+}
+
+QVariantMap QgsShortestPathLayerToPointAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
+{
+  loadCommonParams( parameters, context, feedback );
+
+  QgsPointXY endPoint = parameterAsPoint( parameters, QStringLiteral( "END_POINT" ), context, mNetwork->sourceCrs() );
+
+  std::unique_ptr< QgsFeatureSource > startPoints( parameterAsSource( parameters, QStringLiteral( "START_POINTS" ), context ) );
+  if ( !startPoints )
+    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "START_POINTS" ) ) );
+
+  QgsFields fields = startPoints->fields();
+  fields.append( QgsField( QStringLiteral( "start" ), QVariant::String ) );
+  fields.append( QgsField( QStringLiteral( "end" ), QVariant::String ) );
+  fields.append( QgsField( QStringLiteral( "cost" ), QVariant::Double ) );
+
+  QString dest;
+  std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, fields, QgsWkbTypes::LineString, mNetwork->sourceCrs() ) );
+  if ( !sink )
+    throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) );
+
+  QVector< QgsPointXY > points;
+  points.push_front( endPoint );
+  QHash< int, QgsAttributes > sourceAttributes;
+  loadPoints( startPoints.get(), points, sourceAttributes, context, feedback );
+
+  feedback->pushInfo( QObject::tr( "Building graph…" ) );
+  QVector< QgsPointXY > snappedPoints;
+  mDirector->makeGraph( mBuilder.get(), points, snappedPoints, feedback );
+
+  feedback->pushInfo( QObject::tr( "Calculating shortest paths…" ) );
+  QgsGraph *graph = mBuilder->graph();
+  int idxEnd = graph->findVertex( snappedPoints[0] );
+  int idxStart;
+  int currentIdx;
+
+  QVector< int > tree;
+  QVector< double > costs;
+
+  QVector<QgsPointXY> route;
+  double cost;
+
+  QgsFeature feat;
+  feat.setFields( fields );
+  QgsAttributes attributes;
+
+  int step =  points.size() > 0 ? 100.0 / points.size() : 1;
+  for ( int i = 1; i < points.size(); i++ )
+  {
+    if ( feedback->isCanceled() )
+    {
+      break;
+    }
+
+    idxStart = graph->findVertex( snappedPoints[i] );
+    QgsGraphAnalyzer::dijkstra( graph, idxStart, 0, &tree, &costs );
+
+    if ( tree.at( idxEnd ) == -1 )
+    {
+      feedback->reportError( QObject::tr( "There is no route from start point (%1) to end point (%2)." )
+                             .arg( points[i].toString() )
+                             .arg( endPoint.toString() ) );
+      feat.clearGeometry();
+      attributes = sourceAttributes.value( i );
+      attributes.append( points[i].toString() );
+      feat.setAttributes( attributes );
+      sink->addFeature( feat, QgsFeatureSink::FastInsert );
+      continue;
+    }
+
+    route.clear();
+    route.push_front( graph->vertex( idxEnd ).point() );
+    cost = costs.at( idxEnd );
+    currentIdx = idxEnd;
+    while ( currentIdx != idxStart )
+    {
+      currentIdx = graph->edge( tree.at( currentIdx ) ).fromVertex();
+      route.push_front( graph->vertex( currentIdx ).point() );
+    }
+
+    QgsGeometry geom = QgsGeometry::fromPolylineXY( route );
+    QgsFeature feat;
+    feat.setFields( fields );
+    attributes = sourceAttributes.value( i );
+    attributes.append( points[i].toString() );
+    attributes.append( endPoint.toString() );
+    attributes.append( cost / mMultiplier );
+    feat.setAttributes( attributes );
+    feat.setGeometry( geom );
+    sink->addFeature( feat, QgsFeatureSink::FastInsert );
+
+    feedback->setProgress( i * step );
+  }
+
+  QVariantMap outputs;
+  outputs.insert( QStringLiteral( "OUTPUT" ), dest );
+  return outputs;
+}
+
+///@endcond
diff --git a/src/analysis/processing/qgsalgorithmshortestpathlayertopoint.h b/src/analysis/processing/qgsalgorithmshortestpathlayertopoint.h
@@ -0,0 +1,53 @@
+/***************************************************************************
+                         qgsalgorithmshortestpathlayertopoint.h
+                         ---------------------
+    begin                : JUly 2018
+    copyright            : (C) 2018 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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSALGORITHMSHORTESTPATHLAYERTOPOINT_H
+#define QGSALGORITHMSHORTESTPATHLAYERTOPOINT_H
+
+#define SIP_NO_FILE
+
+#include "qgis.h"
+#include "qgsalgorithmnetworkanalysisbase.h"
+
+///@cond PRIVATE
+
+/**
+ * Native shortest path (layer to point) algorithm.
+ */
+class QgsShortestPathLayerToPointAlgorithm : public QgsNetworkAnalysisAlgorithmBase
+{
+
+  public:
+
+    QgsShortestPathLayerToPointAlgorithm() = default;
+    void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
+    QString name() const override;
+    QString displayName() const override;
+    QStringList tags() const override;
+    QString shortHelpString() const override;
+    QgsShortestPathLayerToPointAlgorithm *createInstance() const override SIP_FACTORY;
+
+  protected:
+
+    QVariantMap processAlgorithm( const QVariantMap &parameters,
+                                  QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+
+};
+
+///@endcond PRIVATE
+
+#endif // QGSALGORITHMSHORTESTPATHLAYERTOPOINT_H
diff --git a/src/analysis/processing/qgsnativealgorithms.cpp b/src/analysis/processing/qgsnativealgorithms.cpp
@@ -74,6 +74,7 @@
 #include "qgsalgorithmrotate.h"
 #include "qgsalgorithmsaveselectedfeatures.h"
 #include "qgsalgorithmsegmentize.h"
+#include "qgsalgorithmshortestpathlayertopoint.h"
 #include "qgsalgorithmshortestpathpointtolayer.h"
 #include "qgsalgorithmshortestpathpointtopoint.h"
 #include "qgsalgorithmsimplify.h"
@@ -198,6 +199,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsSegmentizeByMaximumAngleAlgorithm() );
   addAlgorithm( new QgsSegmentizeByMaximumDistanceAlgorithm() );
   addAlgorithm( new QgsSelectByLocationAlgorithm() );
+  addAlgorithm( new QgsShortestPathLayerToPointAlgorithm() );
   addAlgorithm( new QgsShortestPathPointToLayerAlgorithm() );
   addAlgorithm( new QgsShortestPathPointToPointAlgorithm() );
   addAlgorithm( new QgsSimplifyAlgorithm() );