Processing: Add Fix Geometry algorithm and test: Delete vertex

Part of a processing family to be used after the check geometry processings.
Taking output(s) of such processings as their input(s).

src/analysis/CMakeLists.txt

@@ -61,6 +61,7 @@ set(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmcellstatistics.cpp
   processing/qgsalgorithmcentroid.cpp
   processing/qgsalgorithmcheckgeometryangle.cpp
+  processing/qgsalgorithmdeletevertex.cpp
   processing/qgsalgorithmclip.cpp
   processing/qgsalgorithmconcavehull.cpp
   processing/qgsalgorithmconditionalbranch.cpp

src/analysis/processing/qgsalgorithmdeletevertex.cpp

@@ -0,0 +1,277 @@
+/***************************************************************************
+                        qgsalgorithmdeletevertex.cpp
+                        ---------------------
+   begin                : January 2024
+   copyright            : (C) 2024 by Jacky Volpes
+   email                : jacky dot volpes at oslandia 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 "qgsalgorithmdeletevertex.h"
+#include "qgsgeometrycheckerutils.h"
+#include "qgsgeometryutils.h"
+#include <algorithm>
+
+///@cond PRIVATE
+
+auto QgsDeleteVertexAlgorithm::name() const -> QString
+{
+  return QStringLiteral( "deletevertex" );
+}
+
+auto QgsDeleteVertexAlgorithm::displayName() const -> QString
+{
+  return QObject::tr( "Delete vertices" );
+}
+
+auto QgsDeleteVertexAlgorithm::tags() const -> QStringList
+{
+  return QObject::tr( "delete,vertices" ).split( ',' );
+}
+
+auto QgsDeleteVertexAlgorithm::group() const -> QString
+{
+  return QObject::tr( "Fix geometry" );
+}
+
+auto QgsDeleteVertexAlgorithm::groupId() const -> QString
+{
+  return QStringLiteral( "fixgeometry" );
+}
+
+auto QgsDeleteVertexAlgorithm::shortHelpString() const -> QString
+{
+  return QObject::tr( "This algorithm deletes vertices based on an input layer describing the vertices.\n\n"
+                      "If topological deletion is enabled (default), when deletion of a vertex results in a duplicate vertex"
+                      "(when there is a spike vertex), the duplicate vertex is deleted to keep a single verted." );
+}
+
+auto QgsDeleteVertexAlgorithm::createInstance() const -> QgsDeleteVertexAlgorithm *
+{
+  return new QgsDeleteVertexAlgorithm();
+}
+
+void QgsDeleteVertexAlgorithm::initAlgorithm( const QVariantMap &configuration )
+{
+  Q_UNUSED( configuration )
+
+  // Inputs
+  addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INPUT" ), QObject::tr( "Input layer" ),
+                QList< int >() << static_cast<int>( Qgis::ProcessingSourceType::VectorPolygon ) << static_cast<int>( Qgis::ProcessingSourceType::VectorLine ) )
+              );
+  addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "ERRORS" ), QObject::tr( "Errors layer" ),
+                QList< int >() << static_cast<int>( Qgis::ProcessingSourceType::VectorPoint ) )
+              );
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "FEAT_ID" ), QObject::tr( "Field of feature ID" ),
+                  QStringLiteral( "gc_featid" ), QStringLiteral( "ERRORS" ),
+                  Qgis::ProcessingFieldParameterDataType::Numeric, false, true )
+              );
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "PART_IDX" ), QObject::tr( "Field of part index" ),
+                  QStringLiteral( "gc_partidx" ), QStringLiteral( "ERRORS" ),
+                  Qgis::ProcessingFieldParameterDataType::Numeric, false, true )
+              );
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "RING_IDX" ), QObject::tr( "Field of ring index" ),
+                  QStringLiteral( "gc_ringidx" ), QStringLiteral( "ERRORS" ),
+                  Qgis::ProcessingFieldParameterDataType::Numeric, false, true )
+              );
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "VERTEX_IDX" ), QObject::tr( "Field of vertex index" ),
+                  QStringLiteral( "gc_vertidx" ), QStringLiteral( "ERRORS" ),
+                  Qgis::ProcessingFieldParameterDataType::Numeric, false, true )
+              );
+  addParameter( new QgsProcessingParameterBoolean( QStringLiteral( "TOPOLOGICAL" ), QObject::tr( "Topological deletion" ), true ) );
+
+  // Outputs
+  addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "OUTPUT" ), QObject::tr( "Output layer" ), Qgis::ProcessingSourceType::VectorAnyGeometry ) );
+  addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "REPORT" ), QObject::tr( "Report layer" ), Qgis::ProcessingSourceType::VectorPoint ) );
+
+  std::unique_ptr< QgsProcessingParameterNumber > tolerance = std::make_unique< QgsProcessingParameterNumber >( QStringLiteral( "TOLERANCE" ),
+      QObject::tr( "Tolerance" ), Qgis::ProcessingNumberParameterType::Integer, 8, false, 1, 13 );
+  tolerance->setFlags( tolerance->flags() | Qgis::ProcessingParameterFlag::Advanced );
+  addParameter( tolerance.release() );
+}
+
+auto QgsDeleteVertexAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) -> QVariantMap
+{
+  std::unique_ptr< QgsProcessingFeatureSource > source( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
+  if ( !source )
+    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT" ) ) );
+
+  std::unique_ptr< QgsProcessingFeatureSource > errors( parameterAsSource( parameters, QStringLiteral( "ERRORS" ), context ) );
+  if ( !errors )
+    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "ERRORS" ) ) );
+
+  QgsProcessingMultiStepFeedback multiStepFeedback( 2, feedback );
+
+  QString featIdFieldName = parameterAsString( parameters, QStringLiteral( "FEAT_ID" ), context );
+  QString partIdxFieldName = parameterAsString( parameters, QStringLiteral( "PART_IDX" ), context );
+  QString ringIdxFieldName = parameterAsString( parameters, QStringLiteral( "RING_IDX" ), context );
+  QString vertexIdxFieldName = parameterAsString( parameters, QStringLiteral( "VERTEX_IDX" ), context );
+
+  QString dest_output;
+  std::unique_ptr< QgsFeatureSink > sink_output( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest_output, source->fields(), source->wkbType(), source->sourceCrs() ) );
+  if ( !sink_output )
+    throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) );
+
+  QString dest_report;
+  QgsFields reportFields = errors->fields();
+  reportFields.append( QgsField( QStringLiteral( "report" ), QVariant::String ) );
+  std::unique_ptr< QgsFeatureSink > sink_report( parameterAsSink( parameters, QStringLiteral( "REPORT" ), context, dest_report, reportFields, errors->wkbType(), errors->sourceCrs() ) );
+  if ( !sink_report )
+    throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "REPORT" ) ) );
+
+  // **Preparation step**
+  //
+  // Go through every feature in the errors layer to build the list of vertices to delete.
+  //
+  // We want to have the list ordered by descending feature id, descending part, descending ring, and descending vertex number.
+  // So in the next step we can remove the vertices in an order such that no index will change (always from the last vertex of the geometry to the first).
+  //
+  // To achieve that, when adding a new vertex to the list we search for the first element of the list that has a smaller index than
+  // the vertex we want to insert, ant insert it right before it.
+  //
+  // Our list is in fact a map named verticesMap, whose key is the line/polygon feature on which we delete the vertices,
+  // and whose value is a list of feature id from the input errors layer and the corresponding vertex object build from it.
+
+  multiStepFeedback.setCurrentStep( 1 );
+  multiStepFeedback.setProgressText( QObject::tr( "Preparing deletion…" ) );
+  double step{errors->featureCount() > 0 ? 100.0 / ( double )errors->featureCount() : 1};
+  long i = 0;
+  multiStepFeedback.setProgress( 0.0 );
+  QgsFeature reportFeature;
+  reportFeature.setFields( reportFields );
+  QgsFeature errorFeature;
+  QgsFeatureIterator featureIt = errors->getFeatures();
+  QMap<QgsFeatureId, QList<QPair<QgsFeatureId, QgsVertexId>>> verticesMap;  // see explanation above
+  QgsFeatureIds sourceFeatureIds = source->allFeatureIds();
+  while ( featureIt.nextFeature( errorFeature ) )
+  {
+    const QgsFeatureId errorFeatureId = errorFeature.id();
+    const QgsFeatureId featureId = errorFeature.attribute( featIdFieldName ).toInt();
+    const QgsVertexId vidx = QgsVertexId( errorFeature.attribute( partIdxFieldName ).toInt(),
+                                          errorFeature.attribute( ringIdxFieldName ).toInt(),
+                                          errorFeature.attribute( vertexIdxFieldName ).toInt() );
+
+    if ( !sourceFeatureIds.contains( featureId ) )
+    {
+      reportFeature.setAttributes( errorFeature.attributes() << QObject::tr( "Source feature not found" ) );
+      reportFeature.setGeometry( errorFeature.geometry() );
+      if ( !sink_report->addFeature( reportFeature, QgsFeatureSink::FastInsert ) )
+        throw QgsProcessingException( writeFeatureError( sink_report.get(), parameters, QStringLiteral( "REPORT" ) ) );
+      continue;
+    }
+
+    if ( !verticesMap.contains( featureId ) )  // no vertex of this feature id yet
+      verticesMap[featureId] = QList<QPair<QgsFeatureId, QgsVertexId>>() << QPair<QgsFeatureId, QgsVertexId>( errorFeatureId, vidx );
+    else  // there already is a vertex (or vertices) for this feature: insert the new one at the right place (see explanation above)
+    {
+      QList<QPair<QgsFeatureId, QgsVertexId>> &vertices = verticesMap[featureId];
+      auto it = std::find_if( vertices.begin(), vertices.end(), [&vidx]( QPair<QgsFeatureId, QgsVertexId> pair )
+      {
+        QgsVertexId v = pair.second;
+        if ( v.part == vidx.part )
+        {
+          if ( v.ring == vidx.ring )
+            return v.vertex <= vidx.vertex;
+          return v.ring < vidx.ring;
+        }
+        return v.part < vidx.part;
+      } );
+      vertices.insert( it, QPair<QgsFeatureId, QgsVertexId>( errorFeatureId, vidx ) );
+    }
+    multiStepFeedback.setProgress( 100.0 * step * static_cast<double>( i ) );
+  }
+
+  QgsFeature sourceFeature;
+  QgsFeatureIterator sourceFeatureIt = source->getFeatures();
+  step = source->featureCount() > 0 ? 100.0 / ( double )source->featureCount() : 1;
+  i = 0;
+  multiStepFeedback.setCurrentStep( 2 );
+  multiStepFeedback.setProgressText( QObject::tr( "Deleting vertices…" ) );
+  multiStepFeedback.setProgress( 0.0 );
+  while ( sourceFeatureIt.nextFeature( sourceFeature ) )
+  {
+    QgsFeatureId sourceFeatureId = sourceFeature.id();
+    QgsGeometry sourceGeometry = sourceFeature.geometry();
+    QgsAbstractGeometry *geometry = sourceGeometry.get();
+    if ( verticesMap.contains( sourceFeatureId ) )
+    {
+      QList<QPair<QgsFeatureId, QgsVertexId>> verticesList = verticesMap[sourceFeatureId];
+      for ( auto errorIt = verticesList.cbegin(); errorIt != verticesList.cend(); ++errorIt )
+      {
+        QString reportMessage;
+        QgsVertexId vidx = errorIt->second;
+        QgsFeatureId errorFeatureId = errorIt->first;
+        errors->getFeatures( QgsFeatureRequest( errorFeatureId ) ).nextFeature( errorFeature );
+
+        try
+        {
+          if ( !vidx.isValid( geometry ) )
+            throw QObject::tr( "vidx not valid" );
+
+          // Check if error still applies
+          const int n = QgsGeometryCheckerUtils::polyLineSize( geometry, vidx.part, vidx.ring );
+          if ( n == 0 )
+            throw QObject::tr( "No more vertex in geometry" );
+
+          if ( !QgsGeometryCheckerUtils::canDeleteVertex( geometry, vidx.part, vidx.ring ) )
+            throw QObject::tr( "Resulting geometry would be degenerate" );
+          else if ( !geometry->deleteVertex( vidx ) )
+            throw QObject::tr( "Failed to delete vertex" );
+          else
+          {
+            reportMessage = QObject::tr( "Vertex removed" );
+
+            if ( parameterAsBool( parameters, QStringLiteral( "TOPOLOGICAL" ), context ) )  // Avoid duplicate nodes as result of deleting spike vertex
+            {
+              const QgsPoint &p1 = geometry->vertexAt( QgsVertexId( vidx.part, vidx.ring, ( vidx.vertex - 1 + n ) % n ) );
+              const QgsPoint &p3 = geometry->vertexAt( QgsVertexId( vidx.part, vidx.ring, vidx.vertex ) );
+              if ( QgsGeometryUtils::sqrDistance2D( p1, p3 ) < ( std::pow( 10, -mTolerance ) * std::pow( 10, -mTolerance ) ) &&
+                   QgsGeometryCheckerUtils::canDeleteVertex( geometry, vidx.part, vidx.ring ) &&
+                   geometry->deleteVertex( vidx ) )
+                reportMessage = QObject::tr( "Double vertex removed" );
+            }
+          }
+        }
+        catch ( QString errorMessage )
+        {
+          reportMessage = errorMessage;
+        }
+        reportFeature.setAttributes( errorFeature.attributes() << reportMessage );
+        reportFeature.setGeometry( errorFeature.geometry() );
+        if ( !sink_report->addFeature( reportFeature, QgsFeatureSink::FastInsert ) )
+          throw QgsProcessingException( writeFeatureError( sink_report.get(), parameters, QStringLiteral( "REPORT" ) ) );
+      }
+    }
+    sourceFeature.setGeometry( sourceGeometry );
+    if ( !sink_output->addFeature( sourceFeature, QgsFeatureSink::FastInsert ) )
+      throw QgsProcessingException( writeFeatureError( sink_output.get(), parameters, QStringLiteral( "OUTPUT" ) ) );
+    multiStepFeedback.setProgress( 100.0 * step * static_cast<double>( i ) );
+  }
+
+  QVariantMap outputs;
+  outputs.insert( QStringLiteral( "OUTPUT" ), dest_output );
+  outputs.insert( QStringLiteral( "REPORT" ), dest_report );
+
+  return outputs;
+}
+
+auto QgsDeleteVertexAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback * ) -> bool
+{
+  mTolerance = parameterAsInt( parameters, QStringLiteral( "TOLERANCE" ), context );
+
+  return true;
+}
+
+///@endcond

src/analysis/processing/qgsalgorithmdeletevertex.h

@@ -0,0 +1,54 @@
+/***************************************************************************
+                        qgsalgorithmdeletevertex.h
+                        ---------------------
+   begin                : January 2024
+   copyright            : (C) 2024 by Jacky Volpes
+   email                : jacky dot volpes at oslandia 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 QGSALGORITHMDELETEVERTEX_H
+#define QGSALGORITHMDELETEVERTEX_H
+
+#define SIP_NO_FILE
+
+#include "qgis_sip.h"
+#include "qgsprocessingalgorithm.h"
+
+///@cond PRIVATE
+
+class QgsDeleteVertexAlgorithm : public QgsProcessingAlgorithm
+{
+  public:
+
+    QgsDeleteVertexAlgorithm() = default;
+    void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
+    QString name() const override;
+    QString displayName() const override;
+    QStringList tags() const override;
+    QString group() const override;
+    QString groupId() const override;
+    QString shortHelpString() const override;
+    QgsDeleteVertexAlgorithm *createInstance() const override SIP_FACTORY;
+
+  protected:
+
+    bool prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+    QVariantMap processAlgorithm( const QVariantMap &parameters,
+                                  QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+  private:
+
+    int mTolerance{8};
+};
+
+///@endcond PRIVATE
+
+#endif // QGSALGORITHMDELETEVERTEX_H

src/analysis/processing/qgsnativealgorithms.cpp

@@ -236,6 +236,7 @@
 #include "qgsalgorithmzonalstatistics.h"
 #include "qgsalgorithmzonalstatisticsfeaturebased.h"
 #include "qgsalgorithmpolygonstolines.h"
+#include "qgsalgorithmdeletevertex.h"
 #include "qgsbookmarkalgorithms.h"
 #include "qgsprojectstylealgorithms.h"
 #include "qgsstylealgorithms.h"
@@ -555,6 +556,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsPolygonsToLinesAlgorithm() );
   addAlgorithm( new QgsDensifyGeometriesByIntervalAlgorithm() );
   addAlgorithm( new QgsDensifyGeometriesByCountAlgorithm() );
+  addAlgorithm( new QgsDeleteVertexAlgorithm() );
 }
 
 ///@endcond

tests/src/analysis/CMakeLists.txt

@@ -23,6 +23,7 @@ set(TESTS
  testqgsprocessingalgspt1.cpp
  testqgsprocessingalgspt2.cpp
  testqgsprocessingcheckgeometry.cpp
+ testqgsprocessingfixgeometry.cpp
  testqgsprocessingmodelalgorithm.cpp
  testqgszonalstatistics.cpp
  testqgsrastercalculator.cpp