qgsalgorithmdensifygeometriesbycount.cpp

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/***************************************************************************
                         qgsalgorithmdensifygeometries.cpp
                         ---------------------
    begin                : October 2019
    copyright            : (C) 2019 by Clemens Raffler
    email                : clemens dot raffler 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 "qgsalgorithmdensifygeometriesbycount.h"
 
 
QString QgsDensifyGeometriesByCountAlgorithm::name() const
{
  return QStringLiteral( "densifygeometries" );
}
 
QString QgsDensifyGeometriesByCountAlgorithm::displayName() const
{
  return QObject::tr( "Densify by count" );
}
 
QStringList QgsDensifyGeometriesByCountAlgorithm::tags() const
{
  return QObject::tr( "add,vertex,vertices,points,nodes" ).split( ',' );
}
 
QString QgsDensifyGeometriesByCountAlgorithm::group() const
{
  return QObject::tr( "Vector geometry" );
}
 
QString QgsDensifyGeometriesByCountAlgorithm::groupId() const
{
  return QStringLiteral( "vectorgeometry" );
}
 
QString QgsDensifyGeometriesByCountAlgorithm::shortHelpString() const
{
  return QObject::tr( "This algorithm takes a polygon or line layer "
                      "and generates a new one in which the geometries "
                      "have a larger number of vertices than the "
                      "original one.\n\n If the geometries have z or m values "
                      "present then these will be linearly interpolated "
                      "at the added nodes.\n\n The number of new vertices to "
                      "add to each feature geometry is specified "
                      "as an input parameter." );
}
 
QString QgsDensifyGeometriesByCountAlgorithm::shortDescription() const
{
  return QObject::tr( "Creates a densified version of geometries." );
}
 
QgsDensifyGeometriesByCountAlgorithm *QgsDensifyGeometriesByCountAlgorithm::createInstance() const
{
  return new QgsDensifyGeometriesByCountAlgorithm;
 
}
 
QList<int> QgsDensifyGeometriesByCountAlgorithm::inputLayerTypes() const
{
  return QList<int>() << QgsProcessing::TypeVectorLine << QgsProcessing::TypeVectorPolygon;
}
 
void QgsDensifyGeometriesByCountAlgorithm::initParameters( const QVariantMap &configuration )
{
  Q_UNUSED( configuration )
  std::unique_ptr<QgsProcessingParameterNumber> verticesCnt = qgis::make_unique<QgsProcessingParameterNumber>( QStringLiteral( "VERTICES" ),
      QObject::tr( "Number of vertices to add" ),
      QgsProcessingParameterNumber::Integer,
      1, false, 1, 10000000 );
  verticesCnt->setIsDynamic( true );
  verticesCnt->setDynamicPropertyDefinition( QgsPropertyDefinition( QStringLiteral( "VerticesCount" ), QObject::tr( "Vertices count" ), QgsPropertyDefinition::IntegerPositive ) );
  verticesCnt->setDynamicLayerParameterName( QStringLiteral( "INPUT" ) );
  addParameter( verticesCnt.release() );
}
 
QString QgsDensifyGeometriesByCountAlgorithm::outputName() const
{
  return QObject::tr( "Densified" );
}
 
bool QgsDensifyGeometriesByCountAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  Q_UNUSED( feedback )
  mVerticesCnt = parameterAsInt( parameters, QStringLiteral( "VERTICES" ), context );
 
  mDynamicVerticesCnt = QgsProcessingParameters::isDynamic( parameters, QStringLiteral( "VERTICES" ) );
  if ( mDynamicVerticesCnt )
    mVerticesCntProperty = parameters.value( QStringLiteral( "VERTICES" ) ).value< QgsProperty >();
 
  return true;
}
 
QgsFeatureList QgsDensifyGeometriesByCountAlgorithm::processFeature( const QgsFeature &feature, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  Q_UNUSED( context )
  Q_UNUSED( feedback )
 
  QgsFeature densifiedFeature = feature;
 
  if ( feature.hasGeometry() )
  {
    int verticesCnt = mVerticesCnt;
    if ( mDynamicVerticesCnt )
      verticesCnt = mVerticesCntProperty.valueAsInt( context.expressionContext(), verticesCnt );
 
    if ( verticesCnt > 0 )
      densifiedFeature.setGeometry( feature.geometry().densifyByCount( verticesCnt ) );
  }
 
  return QgsFeatureList() << densifiedFeature;
}