Merge pull request #8906 from m-kuhn/native_polygons_to_lines

Add native polygonstolines algorithm
qgis · Jan 21, 2019 · 8db14d8 · 8db14d8
2 parents eafedee + 1b7932a
commit 8db14d8
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Showing 9 changed files with 325 additions and 136 deletions.
diff --git a/python/plugins/processing/algs/qgis/PolygonsToLines.py b/python/plugins/processing/algs/qgis/PolygonsToLines.py
diff --git a/python/plugins/processing/algs/qgis/QgisAlgorithmProvider.py b/python/plugins/processing/algs/qgis/QgisAlgorithmProvider.py
@@ -98,7 +98,6 @@
 from .PointsToPaths import PointsToPaths
 from .PoleOfInaccessibility import PoleOfInaccessibility
 from .Polygonize import Polygonize
-from .PolygonsToLines import PolygonsToLines
 from .PostGISExecuteSQL import PostGISExecuteSQL
 from .PostGISExecuteAndLoadSQL import PostGISExecuteAndLoadSQL
 from .RandomExtract import RandomExtract
@@ -210,7 +209,6 @@ def getAlgs(self):
                 PointsToPaths(),
                 PoleOfInaccessibility(),
                 Polygonize(),
-                PolygonsToLines(),
                 PostGISExecuteSQL(),
                 PostGISExecuteAndLoadSQL(),
                 RandomExtract(),

diff --git a/src/analysis/CMakeLists.txt b/src/analysis/CMakeLists.txt
@@ -73,6 +73,7 @@ SET(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmorientedminimumboundingbox.cpp
   processing/qgsalgorithmpackage.cpp
   processing/qgsalgorithmarrayoffsetlines.cpp
+  processing/qgsalgorithmpolygonstolines.cpp
   processing/qgsalgorithmpointonsurface.cpp
   processing/qgsalgorithmprojectpointcartesian.cpp
   processing/qgsalgorithmpromotetomultipart.cpp

diff --git a/src/analysis/processing/qgsalgorithmpolygonstolines.cpp b/src/analysis/processing/qgsalgorithmpolygonstolines.cpp
@@ -0,0 +1,157 @@
+/***************************************************************************
+                         qgsalgorithmpolygonstolines.cpp
+                         ---------------------
+    begin                : January 2019
+    copyright            : (C) 2019 by Matthias Kuhn
+    email                : matthias@opengis.ch
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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 "qgsalgorithmpolygonstolines.h"
+#include "qgsgeometrycollection.h"
+#include "qgscurvepolygon.h"
+#include "qgscurve.h"
+#include "qgsmultilinestring.h"
+
+///@cond PRIVATE
+
+QString QgsPolygonsToLinesAlgorithm::name() const
+{
+  return QStringLiteral( "polygonstolines" );
+}
+
+QString QgsPolygonsToLinesAlgorithm::displayName() const
+{
+  return QObject::tr( "Polygons to lines" );
+}
+
+QStringList QgsPolygonsToLinesAlgorithm::tags() const
+{
+  return QObject::tr( "line,polygon,convert" ).split( ',' );
+}
+
+QString QgsPolygonsToLinesAlgorithm::group() const
+{
+  return QObject::tr( "Vector creation" );
+}
+
+QString QgsPolygonsToLinesAlgorithm::groupId() const
+{
+  return QStringLiteral( "vectorgeometry" );
+}
+
+QString QgsPolygonsToLinesAlgorithm::outputName() const
+{
+  return QObject::tr( "Lines" );
+}
+
+QgsProcessing::SourceType QgsPolygonsToLinesAlgorithm::outputLayerType() const
+{
+  return QgsProcessing::TypeVectorLine;
+}
+
+QgsWkbTypes::Type QgsPolygonsToLinesAlgorithm::outputWkbType( QgsWkbTypes::Type inputWkbType ) const
+{
+  QgsWkbTypes::Type wkbType = QgsWkbTypes::Unknown;
+
+  if ( QgsWkbTypes::singleType( QgsWkbTypes::flatType( inputWkbType ) ) == QgsWkbTypes::Polygon )
+    wkbType = QgsWkbTypes::MultiLineString;
+  else if ( QgsWkbTypes::singleType( QgsWkbTypes::flatType( inputWkbType ) ) == QgsWkbTypes::CurvePolygon )
+    wkbType = QgsWkbTypes::MultiCurve;
+
+  if ( QgsWkbTypes::hasM( inputWkbType ) )
+    wkbType = QgsWkbTypes::addM( wkbType );
+  if ( QgsWkbTypes::hasZ( inputWkbType ) )
+    wkbType = QgsWkbTypes::addZ( wkbType );
+
+  return wkbType;
+}
+
+QString QgsPolygonsToLinesAlgorithm::shortHelpString() const
+{
+  return QObject::tr( "Converts polygons to lines" );
+}
+
+QString QgsPolygonsToLinesAlgorithm::shortDescription() const
+{
+  return QObject::tr( "Converts polygons to lines." );
+}
+
+QgsPolygonsToLinesAlgorithm *QgsPolygonsToLinesAlgorithm::createInstance() const
+{
+  return new QgsPolygonsToLinesAlgorithm();
+}
+
+QList<int> QgsPolygonsToLinesAlgorithm::inputLayerTypes() const
+{
+  return QList<int>() << QgsProcessing::TypeVectorPolygon;
+}
+
+QgsFeatureList QgsPolygonsToLinesAlgorithm::processFeature( const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback * )
+{
+  Q_UNUSED( context )
+
+  QgsFeatureList result;
+  QgsFeature feat = feature;
+  if ( feat.hasGeometry() )
+    feat.setGeometry( convertToLines( feat.geometry() ) );
+
+  result << feat;
+  return result;
+}
+
+QgsGeometry QgsPolygonsToLinesAlgorithm::convertToLines( const QgsGeometry &geometry ) const
+{
+  auto rings = extractRings( geometry.constGet() );
+
+  QgsWkbTypes::Type resultType = outputWkbType( geometry.wkbType() );
+
+  std::unique_ptr<QgsMultiCurve> lineGeometry;
+
+  if ( QgsWkbTypes::flatType( resultType ) == QgsWkbTypes::MultiLineString )
+    lineGeometry = qgis::make_unique<QgsMultiLineString>();
+  else
+    lineGeometry = qgis::make_unique<QgsMultiCurve>();
+
+  for ( auto ring : qgis::as_const( rings ) )
+    lineGeometry->addGeometry( ring );
+
+  return QgsGeometry( lineGeometry.release() );
+}
+
+QList<QgsCurve *> QgsPolygonsToLinesAlgorithm::extractRings( const QgsAbstractGeometry *geom ) const
+{
+  QList<QgsCurve *> rings;
+
+  if ( QgsGeometryCollection *collection = qgsgeometry_cast<QgsGeometryCollection *>( geom ) )
+  {
+    QgsGeometryPartIterator parts = collection->parts();
+    while ( parts.hasNext() )
+      rings.append( extractRings( parts.next() ) );
+  }
+  else if ( QgsCurvePolygon *polygon = qgsgeometry_cast<QgsCurvePolygon *>( geom ) )
+  {
+    if ( auto exteriorRing = polygon->exteriorRing() )
+      rings.append( exteriorRing->clone() );
+    for ( int i = 0; i < polygon->numInteriorRings(); ++i )
+    {
+      rings.append( polygon->interiorRing( i )->clone() );
+    }
+  }
+
+  return rings;
+}
+
+
+
+///@endcond
+
+
diff --git a/src/analysis/processing/qgsalgorithmpolygonstolines.h b/src/analysis/processing/qgsalgorithmpolygonstolines.h
@@ -0,0 +1,62 @@
+/***************************************************************************
+                         qgsalgorithmpolygontolines.h
+                         ---------------------
+    begin                : January 2019
+    copyright            : (C) 2019 by Matthias Kuhn
+    email                : matthias@opengis.ch
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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 QGSALGORITHMPOLYGONSTOLINES_H
+#define QGSALGORITHMPOLYGONSTOLINES_H
+
+#define SIP_NO_FILE
+
+#include "qgis.h"
+#include "qgsprocessingalgorithm.h"
+
+///@cond PRIVATE
+
+/**
+ * Native convert polygons to lines algorithm
+ */
+class QgsPolygonsToLinesAlgorithm : public QgsProcessingFeatureBasedAlgorithm
+{
+
+  public:
+
+    QgsPolygonsToLinesAlgorithm() = default;
+    QString name() const override;
+    QString displayName() const override;
+    QStringList tags() const override;
+    QString group() const override;
+    QString groupId() const override;
+    QString shortHelpString() const override;
+    QString shortDescription() const override;
+    QgsPolygonsToLinesAlgorithm *createInstance() const override SIP_FACTORY;
+    QList<int> inputLayerTypes() const override;
+
+  protected:
+    QString outputName() const override;
+    QgsProcessing::SourceType outputLayerType() const override;
+    QgsWkbTypes::Type outputWkbType( QgsWkbTypes::Type inputWkbType ) const override;
+    QgsFeatureList processFeature( const QgsFeature &feature,  QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+
+  private:
+    QgsGeometry convertToLines( const QgsGeometry &geometry ) const;
+    QList<QgsCurve *> extractRings( const QgsAbstractGeometry *geom ) const;
+};
+
+///@endcond PRIVATE
+
+#endif // QGSALGORITHMPOLYGONSTOLINES_H
+
+
diff --git a/src/analysis/processing/qgsnativealgorithms.cpp b/src/analysis/processing/qgsnativealgorithms.cpp
@@ -106,7 +106,7 @@
 #include "qgsalgorithmvectorize.h"
 #include "qgsalgorithmwedgebuffers.h"
 #include "qgsalgorithmzonalhistogram.h"
-
+#include "qgsalgorithmpolygonstolines.h"
 
 ///@cond PRIVATE
 
@@ -245,6 +245,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsVariableWidthBufferByMAlgorithm() );
   addAlgorithm( new QgsWedgeBuffersAlgorithm() );
   addAlgorithm( new QgsZonalHistogramAlgorithm() );
+  addAlgorithm( new QgsPolygonsToLinesAlgorithm() );
 }