qgsgeometry.cpp

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/***************************************************************************
  qgsgeometry.cpp - Geometry (stored as Open Geospatial Consortium WKB)
  -------------------------------------------------------------------
Date                 : 02 May 2005
Copyright            : (C) 2005 by Brendan Morley
email                : morb at ozemail dot com dot au
 ***************************************************************************
 *                                                                         *
 *   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 "qgsgeometry.h"
 
#include <cmath>
#include <cstdarg>
#include <cstdio>
#include <geos_c.h>
#include <limits>
#include <nlohmann/json.hpp>
 
#include "qgis.h"
#include "qgsabstractgeometry.h"
#include "qgscircle.h"
#include "qgscurve.h"
#include "qgscurvepolygon.h"
#include "qgsgeometryeditutils.h"
#include "qgsgeometryfactory.h"
#include "qgsgeometryutils.h"
#include "qgsgeometryvalidator.h"
#include "qgsgeos.h"
#include "qgsinternalgeometryengine.h"
#include "qgslinestring.h"
#include "qgsmaptopixel.h"
#include "qgsmulticurve.h"
#include "qgsmultilinestring.h"
#include "qgsmultipoint.h"
#include "qgsmultipolygon.h"
#include "qgsmultisurface.h"
#include "qgsnurbsutils.h"
#include "qgspoint.h"
#include "qgspointxy.h"
#include "qgspolygon.h"
#include "qgspolyhedralsurface.h"
#include "qgsrectangle.h"
#include "qgstriangle.h"
#include "qgstriangulatedsurface.h"
#include "qgsvectorlayer.h"
 
#include <QString>
 
#ifdef WITH_SFCGAL
#include "qgssfcgalgeometry.h"
#endif
 
#include <QCache>
#include <QString>
 
#include "moc_qgsgeometry.cpp"
 
using namespace Qt::StringLiterals;
 
struct QgsGeometryPrivate
{
    QgsGeometryPrivate()
      : ref( 1 )
    {}
    QgsGeometryPrivate( std::unique_ptr< QgsAbstractGeometry > geometry )
      : ref( 1 )
      , geometry( std::move( geometry ) )
    {}
    QAtomicInt ref;
    std::unique_ptr< QgsAbstractGeometry > geometry;
};
 
QgsGeometry::QgsGeometry()
  : d( new QgsGeometryPrivate() )
{}
 
QgsGeometry::~QgsGeometry()
{
  if ( !d->ref.deref() )
    delete d;
}
 
QgsGeometry::QgsGeometry( QgsAbstractGeometry *geom )
  : d( new QgsGeometryPrivate() )
{
  d->geometry.reset( geom );
}
 
QgsGeometry::QgsGeometry( std::unique_ptr<QgsAbstractGeometry> geom )
  : d( new QgsGeometryPrivate( std::move( geom ) ) )
{}
 
QgsGeometry::QgsGeometry( const QgsGeometry &other )
  : d( other.d )
{
  mLastError = other.mLastError;
  d->ref.ref();
}
 
QgsGeometry &QgsGeometry::operator=( QgsGeometry const &other )
{
  if ( this != &other )
  {
    if ( !d->ref.deref() )
    {
      delete d;
    }
 
    mLastError = other.mLastError;
    d = other.d;
    d->ref.ref();
  }
  return *this;
}
 
void QgsGeometry::detach()
{
  if ( d->ref <= 1 )
    return;
 
  std::unique_ptr< QgsAbstractGeometry > cGeom;
  if ( d->geometry )
    cGeom.reset( d->geometry->clone() );
 
  reset( std::move( cGeom ) );
}
 
void QgsGeometry::reset( std::unique_ptr<QgsAbstractGeometry> newGeometry )
{
  if ( d->ref > 1 )
  {
    ( void ) d->ref.deref();
    d = new QgsGeometryPrivate();
  }
  d->geometry = std::move( newGeometry );
}
 
const QgsAbstractGeometry *QgsGeometry::constGet() const
{
  return d->geometry.get();
}
 
QgsAbstractGeometry *QgsGeometry::get()
{
  detach();
  return d->geometry.get();
}
 
void QgsGeometry::set( QgsAbstractGeometry *geometry )
{
  if ( d->geometry.get() == geometry )
  {
    return;
  }
 
  reset( std::unique_ptr< QgsAbstractGeometry >( geometry ) );
}
 
bool QgsGeometry::isNull() const
{
  return !d->geometry;
}
 
typedef QCache< QString, QgsGeometry > WktCache;
Q_GLOBAL_STATIC_WITH_ARGS( WktCache, sWktCache, ( 2000 ) ) // store up to 2000 geometries
Q_GLOBAL_STATIC( QMutex, sWktMutex )
 
QgsGeometry QgsGeometry::fromWkt( const QString &wkt )
{
  QMutexLocker lock( sWktMutex() );
  if ( const QgsGeometry *cached = sWktCache()->object( wkt ) )
    return *cached;
  const QgsGeometry result( QgsGeometryFactory::geomFromWkt( wkt ) );
  sWktCache()->insert( wkt, new QgsGeometry( result ), 1 );
  return result;
}
 
QgsGeometry QgsGeometry::fromPointXY( const QgsPointXY &point )
{
  std::unique_ptr< QgsAbstractGeometry > geom( QgsGeometryFactory::fromPointXY( point ) );
  if ( geom )
  {
    return QgsGeometry( geom.release() );
  }
  return QgsGeometry();
}
 
QgsGeometry QgsGeometry::fromPoint( const QgsPoint &point )
{
  return QgsGeometry( point.clone() );
}
 
QgsGeometry QgsGeometry::fromPolylineXY( const QgsPolylineXY &polyline )
{
  std::unique_ptr< QgsAbstractGeometry > geom = QgsGeometryFactory::fromPolylineXY( polyline );
  if ( geom )
  {
    return QgsGeometry( std::move( geom ) );
  }
  return QgsGeometry();
}
 
QgsGeometry QgsGeometry::fromPolyline( const QgsPolyline &polyline )
{
  return QgsGeometry( std::make_unique< QgsLineString >( polyline ) );
}
 
QgsGeometry QgsGeometry::fromPolygonXY( const QgsPolygonXY &polygon )
{
  std::unique_ptr< QgsPolygon > geom = QgsGeometryFactory::fromPolygonXY( polygon );
  if ( geom )
  {
    return QgsGeometry( std::move( geom ) );
  }
  return QgsGeometry();
}
 
QgsGeometry QgsGeometry::fromMultiPointXY( const QgsMultiPointXY &multipoint )
{
  std::unique_ptr< QgsMultiPoint > geom = QgsGeometryFactory::fromMultiPointXY( multipoint );
  if ( geom )
  {
    return QgsGeometry( std::move( geom ) );
  }
  return QgsGeometry();
}
 
QgsGeometry QgsGeometry::fromMultiPolylineXY( const QgsMultiPolylineXY &multiline )
{
  std::unique_ptr< QgsMultiLineString > geom = QgsGeometryFactory::fromMultiPolylineXY( multiline );
  if ( geom )
  {
    return QgsGeometry( std::move( geom ) );
  }
  return QgsGeometry();
}
 
QgsGeometry QgsGeometry::fromMultiPolygonXY( const QgsMultiPolygonXY &multipoly )
{
  std::unique_ptr< QgsMultiPolygon > geom = QgsGeometryFactory::fromMultiPolygonXY( multipoly );
  if ( geom )
  {
    return QgsGeometry( std::move( geom ) );
  }
  return QgsGeometry();
}
 
QgsGeometry QgsGeometry::fromRect( const QgsRectangle &rect )
{
  if ( rect.isNull() )
    return QgsGeometry();
 
  auto ext = std::make_unique< QgsLineString >(
    QVector< double >() << rect.xMinimum() << rect.xMaximum() << rect.xMaximum() << rect.xMinimum() << rect.xMinimum(),
    QVector< double >() << rect.yMinimum() << rect.yMinimum() << rect.yMaximum() << rect.yMaximum() << rect.yMinimum()
  );
  auto polygon = std::make_unique< QgsPolygon >();
  polygon->setExteriorRing( ext.release() );
  return QgsGeometry( std::move( polygon ) );
}
 
QgsGeometry QgsGeometry::fromBox3D( const QgsBox3D &box )
{
  if ( box.is2d() )
  {
    return fromRect( box.toRectangle() );
  }
 
  auto polyhedralSurface = std::make_unique< QgsPolyhedralSurface >();
 
  auto ext1 = std::make_unique< QgsLineString >(
    QVector< double >() << box.xMinimum() << box.xMinimum() << box.xMaximum() << box.xMaximum() << box.xMinimum(),
    QVector< double >() << box.yMinimum() << box.yMaximum() << box.yMaximum() << box.yMinimum() << box.yMinimum(),
    QVector< double >() << box.zMinimum() << box.zMinimum() << box.zMinimum() << box.zMinimum() << box.zMinimum()
  );
  auto polygon1 = std::make_unique< QgsPolygon >( ext1.release() );
  polyhedralSurface->addPatch( polygon1.release() );
 
  auto ext2 = std::make_unique< QgsLineString >(
    QVector< double >() << box.xMinimum() << box.xMinimum() << box.xMinimum() << box.xMinimum() << box.xMinimum(),
    QVector< double >() << box.yMinimum() << box.yMaximum() << box.yMaximum() << box.yMinimum() << box.yMinimum(),
    QVector< double >() << box.zMinimum() << box.zMinimum() << box.zMaximum() << box.zMaximum() << box.zMinimum()
  );
  auto polygon2 = std::make_unique< QgsPolygon >( ext2.release() );
  polyhedralSurface->addPatch( polygon2.release() );
 
  auto ext3 = std::make_unique< QgsLineString >(
    QVector< double >() << box.xMinimum() << box.xMaximum() << box.xMaximum() << box.xMinimum() << box.xMinimum(),
    QVector< double >() << box.yMinimum() << box.yMinimum() << box.yMinimum() << box.yMinimum() << box.yMinimum(),
    QVector< double >() << box.zMinimum() << box.zMinimum() << box.zMaximum() << box.zMaximum() << box.zMinimum()
  );
  auto polygon3 = std::make_unique< QgsPolygon >( ext3.release() );
  polyhedralSurface->addPatch( polygon3.release() );
 
  auto ext4 = std::make_unique< QgsLineString >(
    QVector< double >() << box.xMaximum() << box.xMaximum() << box.xMinimum() << box.xMinimum() << box.xMaximum(),
    QVector< double >() << box.yMaximum() << box.yMinimum() << box.yMinimum() << box.yMaximum() << box.yMaximum(),
    QVector< double >() << box.zMaximum() << box.zMaximum() << box.zMaximum() << box.zMaximum() << box.zMaximum()
  );
  auto polygon4 = std::make_unique< QgsPolygon >( ext4.release() );
  polyhedralSurface->addPatch( polygon4.release() );
 
  auto ext5 = std::make_unique< QgsLineString >(
    QVector< double >() << box.xMaximum() << box.xMaximum() << box.xMaximum() << box.xMaximum() << box.xMaximum(),
    QVector< double >() << box.yMaximum() << box.yMinimum() << box.yMinimum() << box.yMaximum() << box.yMaximum(),
    QVector< double >() << box.zMaximum() << box.zMaximum() << box.zMinimum() << box.zMinimum() << box.zMaximum()
  );
  auto polygon5 = std::make_unique< QgsPolygon >( ext5.release() );
  polyhedralSurface->addPatch( polygon5.release() );
 
  auto ext6 = std::make_unique< QgsLineString >(
    QVector< double >() << box.xMaximum() << box.xMaximum() << box.xMinimum() << box.xMinimum() << box.xMaximum(),
    QVector< double >() << box.yMaximum() << box.yMaximum() << box.yMaximum() << box.yMaximum() << box.yMaximum(),
    QVector< double >() << box.zMaximum() << box.zMinimum() << box.zMinimum() << box.zMaximum() << box.zMaximum()
  );
  auto polygon6 = std::make_unique< QgsPolygon >( ext6.release() );
  polyhedralSurface->addPatch( polygon6.release() );
 
  return QgsGeometry( std::move( polyhedralSurface ) );
}
 
QgsGeometry QgsGeometry::collectGeometry( const QVector< QgsGeometry > &geometries )
{
  QgsGeometry collected;
 
  for ( const QgsGeometry &g : geometries )
  {
    if ( collected.isNull() )
    {
      collected = g;
      collected.convertToMultiType();
    }
    else
    {
      if ( g.isMultipart() )
      {
        for ( auto p = g.const_parts_begin(); p != g.const_parts_end(); ++p )
        {
          collected.addPartV2( ( *p )->clone() );
        }
      }
      else
      {
        collected.addPart( g );
      }
    }
  }
  return collected;
}
 
QgsGeometry QgsGeometry::collectTinPatches( const QVector<QgsGeometry> &geometries )
{
  auto resultTin = std::make_unique<QgsTriangulatedSurface>();
  bool first = true;
 
  for ( const QgsGeometry &geom : geometries )
  {
    if ( geom.isNull() )
      continue;
 
    const QgsAbstractGeometry *abstractGeom = geom.constGet();
 
    if ( const QgsTriangulatedSurface *tin = qgsgeometry_cast<const QgsTriangulatedSurface *>( abstractGeom ) )
    {
      // Preserve Z/M from first valid geometry
      if ( first )
      {
        if ( tin->is3D() )
          resultTin->addZValue( 0 );
        if ( tin->isMeasure() )
          resultTin->addMValue( 0 );
        first = false;
      }
 
      // Copy all patches (triangles) from the TIN
      for ( int j = 0; j < tin->numPatches(); ++j )
      {
        if ( const QgsPolygon *patch = tin->patchN( j ) )
        {
          resultTin->addPatch( patch->clone() );
        }
      }
    }
    else if ( const QgsTriangle *triangle = qgsgeometry_cast<const QgsTriangle *>( abstractGeom ) )
    {
      // Preserve Z/M from first valid geometry
      if ( first )
      {
        if ( triangle->is3D() )
          resultTin->addZValue( 0 );
        if ( triangle->isMeasure() )
          resultTin->addMValue( 0 );
        first = false;
      }
 
      resultTin->addPatch( triangle->clone() );
    }
  }
 
  if ( resultTin->numPatches() == 0 )
    return QgsGeometry();
 
  return QgsGeometry( std::move( resultTin ) );
}
 
QgsGeometry QgsGeometry::createWedgeBuffer( const QgsPoint &center, const double azimuth, const double angularWidth, const double outerRadius, const double innerRadius )
{
  const double startAngle = azimuth - angularWidth * 0.5;
  const double endAngle = azimuth + angularWidth * 0.5;
 
  return createWedgeBufferFromAngles( center, startAngle, endAngle, outerRadius, innerRadius );
}
 
QgsGeometry QgsGeometry::createWedgeBufferFromAngles( const QgsPoint &center, double startAngle, double endAngle, double outerRadius, double innerRadius )
{
  auto wedge = std::make_unique< QgsCompoundCurve >();
 
  const double DEG_TO_RAD = M_PI / 180.0;
  const double RAD_TO_DEG = 180.0 / M_PI;
 
  const double angularWidth = endAngle - startAngle;
  const bool useShortestArc = QgsGeometryUtilsBase::normalizedAngle( angularWidth * DEG_TO_RAD ) * RAD_TO_DEG <= 180.0;
 
  if ( std::abs( angularWidth ) >= 360.0 )
  {
    auto outerCc = std::make_unique< QgsCompoundCurve >();
 
    QgsCircle outerCircle = QgsCircle( center, outerRadius );
    outerCc->addCurve( outerCircle.toCircularString().release() );
 
    auto cp = std::make_unique< QgsCurvePolygon >();
    cp->setExteriorRing( outerCc.release() );
 
    if ( !qgsDoubleNear( innerRadius, 0.0 ) && innerRadius > 0 )
    {
      auto innerCc = std::make_unique< QgsCompoundCurve >();
 
      QgsCircle innerCircle = QgsCircle( center, innerRadius );
      innerCc->addCurve( innerCircle.toCircularString().release() );
 
      cp->setInteriorRings( { innerCc.release() } );
    }
 
    return QgsGeometry( std::move( cp ) );
  }
 
  const QgsPoint outerP1 = center.project( outerRadius, startAngle );
  const QgsPoint outerP2 = center.project( outerRadius, endAngle );
 
  wedge->addCurve( new QgsCircularString( QgsCircularString::fromTwoPointsAndCenter( outerP1, outerP2, center, useShortestArc ) ) );
 
  if ( !qgsDoubleNear( innerRadius, 0.0 ) && innerRadius > 0 )
  {
    const QgsPoint innerP1 = center.project( innerRadius, startAngle );
    const QgsPoint innerP2 = center.project( innerRadius, endAngle );
    wedge->addCurve( new QgsLineString( outerP2, innerP2 ) );
    wedge->addCurve( new QgsCircularString( QgsCircularString::fromTwoPointsAndCenter( innerP2, innerP1, center, useShortestArc ) ) );
    wedge->addCurve( new QgsLineString( innerP1, outerP1 ) );
  }
  else
  {
    wedge->addCurve( new QgsLineString( outerP2, center ) );
    wedge->addCurve( new QgsLineString( center, outerP1 ) );
  }
 
  auto cp = std::make_unique< QgsCurvePolygon >();
  cp->setExteriorRing( wedge.release() );
  return QgsGeometry( std::move( cp ) );
}
 
void QgsGeometry::fromWkb( unsigned char *wkb, int length )
{
  QgsConstWkbPtr ptr( wkb, length );
  reset( QgsGeometryFactory::geomFromWkb( ptr ) );
  delete[] wkb;
}
 
void QgsGeometry::fromWkb( const QByteArray &wkb )
{
  QgsConstWkbPtr ptr( wkb );
  reset( QgsGeometryFactory::geomFromWkb( ptr ) );
}
 
Qgis::WkbType QgsGeometry::wkbType() const
{
  if ( !d->geometry )
  {
    return Qgis::WkbType::Unknown;
  }
  else
  {
    return d->geometry->wkbType();
  }
}
 
Qgis::GeometryType QgsGeometry::type() const
{
  if ( !d->geometry )
  {
    return Qgis::GeometryType::Unknown;
  }
  return QgsWkbTypes::geometryType( d->geometry->wkbType() );
}
 
bool QgsGeometry::isEmpty() const
{
  if ( !d->geometry )
  {
    return true;
  }
 
  return d->geometry->isEmpty();
}
 
bool QgsGeometry::isMultipart() const
{
  if ( !d->geometry )
  {
    return false;
  }
  return QgsWkbTypes::isMultiType( d->geometry->wkbType() );
}
QgsPointXY QgsGeometry::closestVertex( const QgsPointXY &point, int &closestVertexIndex, int &previousVertexIndex, int &nextVertexIndex, double &sqrDist ) const
{
  if ( !d->geometry )
  {
    sqrDist = -1;
    return QgsPointXY();
  }
 
  QgsPoint pt( point );
  QgsVertexId id;
 
  QgsPoint vp = QgsGeometryUtils::closestVertex( *( d->geometry ), pt, id );
  if ( !id.isValid() )
  {
    sqrDist = -1;
    return QgsPointXY();
  }
  sqrDist = QgsGeometryUtils::sqrDistance2D( pt, vp );
 
  QgsVertexId prevVertex;
  QgsVertexId nextVertex;
  d->geometry->adjacentVertices( id, prevVertex, nextVertex );
  closestVertexIndex = vertexNrFromVertexId( id );
  previousVertexIndex = vertexNrFromVertexId( prevVertex );
  nextVertexIndex = vertexNrFromVertexId( nextVertex );
  return QgsPointXY( vp.x(), vp.y() );
}
 
double QgsGeometry::distanceToVertex( int vertex ) const
{
  if ( !d->geometry )
  {
    return -1;
  }
 
  QgsVertexId id;
  if ( !vertexIdFromVertexNr( vertex, id ) )
  {
    return -1;
  }
 
  return QgsGeometryUtils::distanceToVertex( *( d->geometry ), id );
}
 
double QgsGeometry::angleAtVertex( int vertex ) const
{
  if ( !d->geometry )
  {
    return 0;
  }
 
  QgsVertexId v2;
  if ( !vertexIdFromVertexNr( vertex, v2 ) )
  {
    return 0;
  }
 
  return d->geometry->vertexAngle( v2 );
}
 
void QgsGeometry::adjacentVertices( int atVertex, int &beforeVertex, int &afterVertex ) const
{
  if ( !d->geometry )
  {
    return;
  }
 
  QgsVertexId id;
  if ( !vertexIdFromVertexNr( atVertex, id ) )
  {
    beforeVertex = -1;
    afterVertex = -1;
    return;
  }
 
  QgsVertexId beforeVertexId, afterVertexId;
  d->geometry->adjacentVertices( id, beforeVertexId, afterVertexId );
  beforeVertex = vertexNrFromVertexId( beforeVertexId );
  afterVertex = vertexNrFromVertexId( afterVertexId );
}
 
bool QgsGeometry::moveVertex( double x, double y, int atVertex )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  QgsVertexId id;
  if ( !vertexIdFromVertexNr( atVertex, id ) )
  {
    return false;
  }
 
  detach();
 
  return d->geometry->moveVertex( id, QgsPoint( x, y ) );
}
 
bool QgsGeometry::moveVertex( const QgsPoint &p, int atVertex )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  QgsVertexId id;
  if ( !vertexIdFromVertexNr( atVertex, id ) )
  {
    return false;
  }
 
  detach();
 
  return d->geometry->moveVertex( id, p );
}
 
bool QgsGeometry::deleteVertex( int atVertex )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  //maintain compatibility with < 2.10 API
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::MultiPoint )
  {
    detach();
    //delete geometry instead of point
    return static_cast< QgsGeometryCollection * >( d->geometry.get() )->removeGeometry( atVertex );
  }
 
  //if it is a point, set the geometry to nullptr
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::Point )
  {
    reset( nullptr );
    return true;
  }
 
  QgsVertexId id;
  if ( !vertexIdFromVertexNr( atVertex, id ) )
  {
    return false;
  }
 
  detach();
 
  return d->geometry->deleteVertex( id );
}
 
bool QgsGeometry::deleteVertices( const QSet<int> &atVertices )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  // if it is a point, set the geometry to nullptr
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::Point )
  {
    if ( atVertices.size() != 1 && !atVertices.contains( 0 ) )
      return false;
 
    reset( nullptr );
    return true;
  }
 
  QSet<QgsVertexId> vertexIds;
  for ( int vertex : atVertices )
  {
    QgsVertexId id;
    if ( !vertexIdFromVertexNr( vertex, id ) )
      return false;
 
    vertexIds.insert( id );
  }
 
  // create a copy of the original geometry to restore it in case of failure
  std::unique_ptr< QgsAbstractGeometry > originalGeometry( d->geometry->clone() );
 
  detach();
 
  if ( !d->geometry->deleteVertices( vertexIds ) )
  {
    reset( std::move( originalGeometry ) );
    return false;
  }
 
  return true;
}
 
bool QgsGeometry::toggleCircularAtVertex( int atVertex )
{
  if ( !d->geometry )
    return false;
 
  QgsVertexId id;
  if ( !vertexIdFromVertexNr( atVertex, id ) )
    return false;
 
  detach();
 
  QgsAbstractGeometry *geom = d->geometry.get();
 
  // If the geom is a collection, we get the concerned part, otherwise, the part is just the whole geom
  QgsAbstractGeometry *part = nullptr;
  QgsGeometryCollection *owningCollection = qgsgeometry_cast<QgsGeometryCollection *>( geom );
  if ( owningCollection )
    part = owningCollection->geometryN( id.part );
  else
    part = geom;
 
  // If the part is a polygon, we get the concerned ring, otherwise, the ring is just the whole part
  QgsAbstractGeometry *ring = nullptr;
  QgsCurvePolygon *owningPolygon = qgsgeometry_cast<QgsCurvePolygon *>( part );
  if ( owningPolygon )
    ring = ( id.ring == 0 ) ? owningPolygon->exteriorRing() : owningPolygon->interiorRing( id.ring - 1 );
  else
    ring = part;
 
  // If the ring is not a curve, we're probably on a point geometry
  QgsCurve *curve = qgsgeometry_cast<QgsCurve *>( ring );
  if ( !curve )
    return false;
 
  bool success = false;
  QgsCompoundCurve *cpdCurve = qgsgeometry_cast<QgsCompoundCurve *>( curve );
  if ( cpdCurve )
  {
    // If the geom is a already compound curve, we convert inplace, and we're done
    success = cpdCurve->toggleCircularAtVertex( id );
  }
  else
  {
    // TODO : move this block before the above, so we call toggleCircularAtVertex only in one place
    // If the geom is a linestring or cirularstring, we create a compound curve
    auto cpdCurve = std::make_unique<QgsCompoundCurve>();
    cpdCurve->addCurve( curve->clone() );
    success = cpdCurve->toggleCircularAtVertex( QgsVertexId( -1, -1, id.vertex ) );
 
    // In that case, we must also reassign the instances
    if ( success )
    {
      if ( !owningPolygon && !owningCollection )
      {
        // Standalone linestring
        reset( std::make_unique<QgsCompoundCurve>( *cpdCurve ) ); // <- REVIEW PLZ
      }
      else if ( owningPolygon )
      {
        // Replace the ring in the owning polygon
        if ( id.ring == 0 )
        {
          owningPolygon->setExteriorRing( cpdCurve.release() );
        }
        else
        {
          owningPolygon->removeInteriorRing( id.ring - 1 );
          owningPolygon->addInteriorRing( cpdCurve.release() );
        }
      }
      else if ( owningCollection )
      {
        // Replace the curve in the owning collection
        owningCollection->removeGeometry( id.part );
        owningCollection->insertGeometry( cpdCurve.release(), id.part );
      }
    }
  }
 
  return success;
}
 
bool QgsGeometry::insertVertex( double x, double y, int beforeVertex )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  //maintain compatibility with < 2.10 API
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::MultiPoint )
  {
    detach();
    //insert geometry instead of point
    return static_cast< QgsGeometryCollection * >( d->geometry.get() )->insertGeometry( new QgsPoint( x, y ), beforeVertex );
  }
 
  QgsVertexId id;
  if ( !vertexIdFromVertexNr( beforeVertex, id ) )
  {
    return false;
  }
 
  detach();
 
  return d->geometry->insertVertex( id, QgsPoint( x, y ) );
}
 
bool QgsGeometry::insertVertex( const QgsPoint &point, int beforeVertex )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  //maintain compatibility with < 2.10 API
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::MultiPoint )
  {
    detach();
    //insert geometry instead of point
    return static_cast< QgsGeometryCollection * >( d->geometry.get() )->insertGeometry( new QgsPoint( point ), beforeVertex );
  }
 
  QgsVertexId id;
  if ( !vertexIdFromVertexNr( beforeVertex, id ) )
  {
    return false;
  }
 
  detach();
 
  return d->geometry->insertVertex( id, point );
}
 
bool QgsGeometry::addTopologicalPoint( const QgsPoint &point, double snappingTolerance, double segmentSearchEpsilon )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  const double sqrSnappingTolerance = snappingTolerance * snappingTolerance;
  int segmentAfterVertex;
  QgsPointXY snappedPoint;
  const double sqrDistSegmentSnap = closestSegmentWithContext( point, snappedPoint, segmentAfterVertex, nullptr, segmentSearchEpsilon );
 
  if ( sqrDistSegmentSnap > sqrSnappingTolerance )
    return false;
 
  int atVertex, beforeVertex, afterVertex;
  double sqrDistVertexSnap;
  closestVertex( point, atVertex, beforeVertex, afterVertex, sqrDistVertexSnap );
 
  if ( sqrDistVertexSnap < sqrSnappingTolerance )
    return false; // the vertex already exists - do not insert it
 
  // Let's ignore the Z and M values of the supplied topological point and calculate
  // interpolated values instead, using the previous and next geometry vertices.
  // This should make sure that the geometry's Z and M values are preserved when adding
  // topological points and splitting
  QgsPoint interpolatedPoint( point );
  if ( d->geometry.get()->is3D() || d->geometry.get()->isMeasure() )
  {
    const QgsPoint vertexBefore = vertexAt( segmentAfterVertex - 1 );
    const QgsPoint vertexAfter = vertexAt( segmentAfterVertex );
    interpolatedPoint = QgsGeometryUtils::interpolatePointOnSegment( point.x(), point.y(), vertexBefore, vertexAfter );
  }
 
  if ( !insertVertex( interpolatedPoint, segmentAfterVertex ) )
  {
    QgsDebugError( u"failed to insert topo point"_s );
    return false;
  }
 
  return true;
}
 
QgsPoint QgsGeometry::vertexAt( int atVertex ) const
{
  if ( !d->geometry )
  {
    return QgsPoint();
  }
 
  QgsVertexId vId;
  ( void ) vertexIdFromVertexNr( atVertex, vId );
  if ( vId.vertex < 0 )
  {
    return QgsPoint();
  }
  return d->geometry->vertexAt( vId );
}
 
double QgsGeometry::sqrDistToVertexAt( QgsPointXY &point, int atVertex ) const
{
  QgsPointXY vertexPoint = vertexAt( atVertex );
  return QgsGeometryUtils::sqrDistance2D( QgsPoint( vertexPoint ), QgsPoint( point ) );
}
 
QgsGeometry QgsGeometry::nearestPoint( const QgsGeometry &other ) const
{
  // avoid calling geos for trivial point calculations
  if ( d->geometry && QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::Point )
  {
    return QgsGeometry( qgsgeometry_cast< const QgsPoint * >( d->geometry.get() )->clone() );
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result = QgsGeometry( geos.closestPoint( other ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::shortestLine( const QgsGeometry &other ) const
{
  // avoid calling geos for trivial point-to-point line calculations
  if ( d->geometry && QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::Point && QgsWkbTypes::flatType( other.wkbType() ) == Qgis::WkbType::Point )
  {
    return QgsGeometry( std::make_unique< QgsLineString >( *qgsgeometry_cast< const QgsPoint * >( d->geometry.get() ), *qgsgeometry_cast< const QgsPoint * >( other.constGet() ) ) );
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result = QgsGeometry( geos.shortestLine( other, &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
double QgsGeometry::closestVertexWithContext( const QgsPointXY &point, int &atVertex ) const
{
  if ( !d->geometry )
  {
    return -1;
  }
 
  QgsVertexId vId;
  QgsPoint pt( point );
  QgsPoint closestPoint = QgsGeometryUtils::closestVertex( *( d->geometry ), pt, vId );
  if ( !vId.isValid() )
    return -1;
  atVertex = vertexNrFromVertexId( vId );
  return QgsGeometryUtils::sqrDistance2D( closestPoint, pt );
}
 
double QgsGeometry::closestSegmentWithContext( const QgsPointXY &point, QgsPointXY &minDistPoint, int &nextVertexIndex, int *leftOrRightOfSegment, double epsilon ) const
{
  if ( !d->geometry )
  {
    return -1;
  }
 
  QgsPoint segmentPt;
  QgsVertexId vertexAfter;
 
  double sqrDist = d->geometry->closestSegment( QgsPoint( point ), segmentPt, vertexAfter, leftOrRightOfSegment, epsilon );
  if ( sqrDist < 0 )
    return -1;
 
  minDistPoint.setX( segmentPt.x() );
  minDistPoint.setY( segmentPt.y() );
  nextVertexIndex = vertexNrFromVertexId( vertexAfter );
  return sqrDist;
}
 
Qgis::GeometryOperationResult QgsGeometry::addRing( const QVector<QgsPointXY> &ring )
{
  auto ringLine = std::make_unique< QgsLineString >( ring );
  return addRing( ringLine.release() );
}
 
Qgis::GeometryOperationResult QgsGeometry::addRing( QgsCurve *ring )
{
  std::unique_ptr< QgsCurve > r( ring );
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidInputGeometryType;
  }
 
  detach();
 
  return QgsGeometryEditUtils::addRing( d->geometry.get(), std::move( r ) );
}
 
Qgis::GeometryOperationResult QgsGeometry::addPart( const QVector<QgsPointXY> &points, Qgis::GeometryType geomType )
{
  QgsPointSequence l;
  convertPointList( points, l );
  Q_NOWARN_DEPRECATED_PUSH
  return addPart( l, geomType );
  Q_NOWARN_DEPRECATED_POP
}
 
Qgis::GeometryOperationResult QgsGeometry::addPartV2( const QVector<QgsPointXY> &points, Qgis::WkbType wkbType )
{
  QgsPointSequence l;
  convertPointList( points, l );
  return addPartV2( l, wkbType );
}
 
Qgis::GeometryOperationResult QgsGeometry::addPart( const QgsPointSequence &points, Qgis::GeometryType geomType )
{
  std::unique_ptr< QgsAbstractGeometry > partGeom;
  if ( points.size() == 1 )
  {
    partGeom = std::make_unique< QgsPoint >( points[0] );
  }
  else if ( points.size() > 1 )
  {
    auto ringLine = std::make_unique< QgsLineString >();
    ringLine->setPoints( points );
    partGeom = std::move( ringLine );
  }
  Q_NOWARN_DEPRECATED_PUSH
  return addPart( partGeom.release(), geomType );
  Q_NOWARN_DEPRECATED_POP
}
 
Qgis::GeometryOperationResult QgsGeometry::addPartV2( const QgsPointSequence &points, Qgis::WkbType wkbType )
{
  std::unique_ptr< QgsAbstractGeometry > partGeom;
  if ( points.size() == 1 )
  {
    partGeom = std::make_unique< QgsPoint >( points[0] );
  }
  else if ( points.size() > 1 )
  {
    auto ringLine = std::make_unique< QgsLineString >();
    ringLine->setPoints( points );
    partGeom = std::move( ringLine );
  }
  return addPartV2( partGeom.release(), wkbType );
}
 
Qgis::GeometryOperationResult QgsGeometry::addPart( QgsAbstractGeometry *part, Qgis::GeometryType geomType )
{
  std::unique_ptr< QgsAbstractGeometry > p( part );
  if ( !d->geometry )
  {
    switch ( geomType )
    {
      case Qgis::GeometryType::Point:
        reset( std::make_unique< QgsMultiPoint >() );
        break;
      case Qgis::GeometryType::Line:
        reset( std::make_unique< QgsMultiLineString >() );
        break;
      case Qgis::GeometryType::Polygon:
        reset( std::make_unique< QgsMultiPolygon >() );
        break;
      default:
        reset( nullptr );
        return Qgis::GeometryOperationResult::AddPartNotMultiGeometry;
    }
  }
  else
  {
    detach();
  }
 
  convertToMultiType();
  return QgsGeometryEditUtils::addPart( d->geometry.get(), std::move( p ) );
}
 
Qgis::GeometryOperationResult QgsGeometry::addPartV2( QgsAbstractGeometry *part, Qgis::WkbType wkbType )
{
  std::unique_ptr< QgsAbstractGeometry > p( part );
  if ( !d->geometry )
  {
    switch ( QgsWkbTypes::singleType( QgsWkbTypes::flatType( wkbType ) ) )
    {
      case Qgis::WkbType::Point:
        reset( std::make_unique< QgsMultiPoint >() );
        break;
      case Qgis::WkbType::LineString:
        reset( std::make_unique< QgsMultiLineString >() );
        break;
      case Qgis::WkbType::Polygon:
      case Qgis::WkbType::Triangle:
        reset( std::make_unique< QgsMultiPolygon >() );
        break;
      case Qgis::WkbType::CurvePolygon:
        reset( std::make_unique< QgsMultiSurface >() );
        break;
      case Qgis::WkbType::CompoundCurve:
      case Qgis::WkbType::CircularString:
        reset( std::make_unique< QgsMultiCurve >() );
        break;
      case Qgis::WkbType::PolyhedralSurface:
        reset( std::make_unique< QgsPolyhedralSurface >() );
        break;
      case Qgis::WkbType::TIN:
        reset( std::make_unique< QgsTriangulatedSurface >() );
        break;
      default:
        reset( nullptr );
        return Qgis::GeometryOperationResult::AddPartNotMultiGeometry;
    }
  }
  else
  {
    detach();
    // For TIN and PolyhedralSurface, they already support multiple patches, no conversion needed
    const Qgis::WkbType flatType = QgsWkbTypes::flatType( d->geometry->wkbType() );
    if ( flatType != Qgis::WkbType::TIN && flatType != Qgis::WkbType::PolyhedralSurface )
    {
      convertToMultiType();
    }
  }
 
  return QgsGeometryEditUtils::addPart( d->geometry.get(), std::move( p ) );
}
 
Qgis::GeometryOperationResult QgsGeometry::addPart( const QgsGeometry &newPart )
{
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  }
  if ( newPart.isNull() || !newPart.d->geometry )
  {
    return Qgis::GeometryOperationResult::AddPartNotMultiGeometry;
  }
 
  return addPartV2( newPart.d->geometry->clone() );
}
 
QgsGeometry QgsGeometry::removeInteriorRings( double minimumRingArea ) const
{
  if ( !d->geometry || type() != Qgis::GeometryType::Polygon )
  {
    return QgsGeometry();
  }
 
  if ( QgsWkbTypes::isMultiType( d->geometry->wkbType() ) )
  {
    const QVector<QgsGeometry> parts = asGeometryCollection();
    QVector<QgsGeometry> results;
    results.reserve( parts.count() );
    for ( const QgsGeometry &part : parts )
    {
      QgsGeometry result = part.removeInteriorRings( minimumRingArea );
      if ( !result.isNull() )
        results << result;
    }
    if ( results.isEmpty() )
      return QgsGeometry();
 
    QgsGeometry first = results.takeAt( 0 );
    for ( const QgsGeometry &result : std::as_const( results ) )
    {
      first.addPart( result );
    }
    return first;
  }
  else
  {
    std::unique_ptr< QgsCurvePolygon > newPoly( static_cast< QgsCurvePolygon * >( d->geometry->clone() ) );
    newPoly->removeInteriorRings( minimumRingArea );
    return QgsGeometry( std::move( newPoly ) );
  }
}
 
Qgis::GeometryOperationResult QgsGeometry::translate( double dx, double dy, double dz, double dm )
{
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  }
 
  detach();
 
  d->geometry->transform( QTransform::fromTranslate( dx, dy ), dz, 1.0, dm );
  return Qgis::GeometryOperationResult::Success;
}
 
Qgis::GeometryOperationResult QgsGeometry::rotate( double rotation, const QgsPointXY &center )
{
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  }
 
  detach();
 
  QTransform t = QTransform::fromTranslate( center.x(), center.y() );
  t.rotate( -rotation );
  t.translate( -center.x(), -center.y() );
  d->geometry->transform( t );
  return Qgis::GeometryOperationResult::Success;
}
 
// TODO: Remove this method when reshape() no longer calls it.
// i.e., when adapted to GEOS 3.15, since GEOS does the right thing.
static void removeDuplicateAdjacentPointsAt( QgsAbstractGeometry *geom, const QgsPointSequence &points )
{
  // this is a workaround for removing duplicated points introduced by GEOS when splitting 3d geometries
  // on topologically added points. It makes no sense to be called for 2d geometries, so it shouldn't.
  if ( !geom->is3D() )
  {
    Q_ASSERT( false );
    return;
  }
 
  for ( const QgsPoint &pt : points )
  {
    QgsVertexId vertexId, prevVertexId, nextVertexId;
    const QgsPoint closestPt = QgsGeometryUtils::closestVertex( *geom, pt, vertexId );
    geom->adjacentVertices( vertexId, prevVertexId, nextVertexId );
    const double dist = QgsGeometryUtils::sqrDistance2D( pt, closestPt );
    if ( dist == 0 )
    {
      // make sure the geometry is snapped (z) to the topo point
      ( void ) geom->moveVertex( vertexId, pt );
      // remove adjacent vertices which are duplicates on the XY plane
      if ( const QgsPoint v = geom->vertexAt( prevVertexId ); v.x() == pt.x() && v.y() == pt.y() )
        ( void ) geom->deleteVertex( prevVertexId );
      else if ( const QgsPoint v = geom->vertexAt( nextVertexId ); v.x() == pt.x() && v.y() == pt.y() )
        ( void ) geom->deleteVertex( nextVertexId );
    }
  }
}
 
Qgis::GeometryOperationResult QgsGeometry::splitGeometry(
  const QVector<QgsPointXY> &splitLine, QVector<QgsGeometry> &newGeometries, bool topological, QVector<QgsPointXY> &topologyTestPoints, bool splitFeature
)
{
  QgsPointSequence split, topology;
  convertPointList( splitLine, split );
  convertPointList( topologyTestPoints, topology );
  Qgis::GeometryOperationResult result = splitGeometry( split, newGeometries, topological, topology, splitFeature );
  convertPointList( topology, topologyTestPoints );
  return result;
}
Qgis::GeometryOperationResult QgsGeometry::splitGeometry(
  const QgsPointSequence &splitLine, QVector<QgsGeometry> &newGeometries, bool topological, QgsPointSequence &topologyTestPoints, bool splitFeature, bool skipIntersectionTest
)
{
#if GEOS_VERSION_NUM >= GEOS_COMPUTE_VERSION( 3, 15, 0 )
  Q_UNUSED( skipIntersectionTest )
#endif
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  }
  if ( splitLine.isEmpty() )
  {
    return Qgis::GeometryOperationResult::InvalidInputGeometryType;
  }
 
  // We're trying adding the split line's vertices to the geometry so that
  // snap to segment always produces a valid split (see https://github.com/qgis/QGIS/issues/29270)
  QgsGeometry tmpGeom( *this );
  QVector<QgsGeometry > newGeomsTemp;
 
#if GEOS_VERSION_NUM >= GEOS_COMPUTE_VERSION( 3, 15, 0 )
  for ( const QgsPoint &v : splitLine )
  {
    tmpGeom.addTopologicalPoint( v );
  }
 
  std::unique_ptr< QgsAbstractGeometry > splitGeom;
  if ( splitLine.size() > 1 )
  {
    splitGeom = std::make_unique< QgsLineString >( splitLine );
    splitGeom->dropZValue();
    splitGeom->dropMValue();
  }
  else if ( splitLine.size() == 1 )
  {
    splitGeom = std::make_unique< QgsPoint >( splitLine[0].x(), splitLine[0].y() );
  }
  QgsGeos geos( tmpGeom.get() );
  mLastError.clear();
  QgsGeometryEngine::EngineOperationResult result = geos.splitGeometry( *splitGeom.get(), newGeomsTemp, topological, topologyTestPoints, &mLastError );
 
  switch ( result )
  {
    case QgsGeometryEngine::Success:
    {
      newGeometries = collectSplitGeometries( newGeomsTemp, splitFeature );
#else
  QgsPointSequence addedTopologicalPoints;
  for ( const QgsPoint &v : splitLine )
  {
    if ( tmpGeom.addTopologicalPoint( v ) )
    {
      // POLYGON Z geometries need special handling to cater for GEOS limitations.
      // Splitting of polygons relies on GEOS extracting lines, unioning with the split line and then polygonizing.
      // The problem is that during the union operation GEOS will interpolate new Z values where the split line intersects
      // the polygon rings, even though we have added topological points with the correct Z values at that location.
      // This results in duplicate vertices and/or wrong Z values on the split geometry.
      // Our solution for that is:
      // 1. Collect the topo points that were added (these have the desired interpolated Z values).
      // 2. Visit the split geometries at the XY location of those topo points and make sure they still have the desired Z value.
      // 3. Remove the adjacent vertex to the topo point if it has same XY coordinates. Any vertex with XY coordinates same as a
      //    topo point was introduced by GEOS and is not wanted.
      if ( tmpGeom.constGet()->is3D() && tmpGeom.constGet()->dimension() == 2 )
      {
        QgsVertexId vId;
        const QgsPoint topoPoint = QgsGeometryUtils::closestVertex( *tmpGeom.constGet(), v, vId );
        addedTopologicalPoints.append( topoPoint );
      }
    }
  }
 
  QgsLineString splitLineString( splitLine );
  splitLineString.dropZValue();
  splitLineString.dropMValue();
 
  QgsGeos geos( tmpGeom.get() );
  mLastError.clear();
  QgsGeometryEngine::EngineOperationResult result = geos.splitGeometry( splitLineString, newGeomsTemp, topological, topologyTestPoints, &mLastError, skipIntersectionTest );
 
  switch ( result )
  {
    case QgsGeometryEngine::Success:
    {
      if ( !addedTopologicalPoints.isEmpty() )
      {
        for ( int i = 0; i < newGeomsTemp.size(); ++i )
        {
          QgsAbstractGeometry *geom = newGeomsTemp[i].get();
          removeDuplicateAdjacentPointsAt( geom, addedTopologicalPoints );
        }
      }
      if ( splitFeature && !newGeomsTemp.isEmpty() )
        *this = newGeomsTemp.takeAt( 0 );
 
      newGeometries = newGeomsTemp;
#endif
      return Qgis::GeometryOperationResult::Success;
    }
    case QgsGeometryEngine::MethodNotImplemented:
    case QgsGeometryEngine::EngineError:
    case QgsGeometryEngine::NodedGeometryError:
      return Qgis::GeometryOperationResult::GeometryEngineError;
    case QgsGeometryEngine::InvalidBaseGeometry:
      return Qgis::GeometryOperationResult::InvalidBaseGeometry;
    case QgsGeometryEngine::InvalidInput:
      return Qgis::GeometryOperationResult::InvalidInputGeometryType;
    case QgsGeometryEngine::SplitCannotSplitPoint:
      return Qgis::GeometryOperationResult::SplitCannotSplitPoint;
    case QgsGeometryEngine::NothingHappened:
      return Qgis::GeometryOperationResult::NothingHappened;
      //default: do not implement default to handle properly all cases
  }
 
  // this should never be reached
  Q_ASSERT( false );
  return Qgis::GeometryOperationResult::NothingHappened;
}
 
Qgis::GeometryOperationResult QgsGeometry::splitGeometry(
  const QgsCurve *curve, QVector<QgsGeometry> &newGeometries, bool preserveCircular, bool topological, QgsPointSequence &topologyTestPoints, bool splitFeature
)
{
#if GEOS_VERSION_NUM >= GEOS_COMPUTE_VERSION( 3, 15, 0 )
  Q_UNUSED( preserveCircular );
 
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  }
  if ( curve->isEmpty() )
  {
    return Qgis::GeometryOperationResult::InvalidInputGeometryType;
  }
 
  // We're trying adding the split line's vertices to the geometry so that
  // snap to segment always produces a valid split (see https://github.com/qgis/QGIS/issues/29270)
  QgsGeometry tmpGeom( *this );
  QgsPointSequence curvePoints;
  curve->points( curvePoints );
 
  for ( const QgsPoint &v : std::as_const( curvePoints ) )
  {
    tmpGeom.addTopologicalPoint( v );
  }
 
  QVector< QgsGeometry> newGeomsTemp;
 
  QgsGeos geos( tmpGeom.get() );
  mLastError.clear();
  QgsGeometryEngine::EngineOperationResult result = geos.splitGeometry( *curve, newGeomsTemp, topological, topologyTestPoints, &mLastError );
 
  switch ( result )
  {
    case QgsGeometryEngine::Success:
    {
      newGeometries = collectSplitGeometries( newGeomsTemp, splitFeature );
      return Qgis::GeometryOperationResult::Success;
    }
    case QgsGeometryEngine::MethodNotImplemented:
    case QgsGeometryEngine::EngineError:
    case QgsGeometryEngine::NodedGeometryError:
      return Qgis::GeometryOperationResult::GeometryEngineError;
    case QgsGeometryEngine::InvalidBaseGeometry:
      return Qgis::GeometryOperationResult::InvalidBaseGeometry;
    case QgsGeometryEngine::InvalidInput:
      return Qgis::GeometryOperationResult::InvalidInputGeometryType;
    case QgsGeometryEngine::SplitCannotSplitPoint:
      return Qgis::GeometryOperationResult::SplitCannotSplitPoint;
    case QgsGeometryEngine::NothingHappened:
      return Qgis::GeometryOperationResult::NothingHappened;
      //default: do not implement default to handle properly all cases
  }
 
  BUILTIN_UNREACHABLE
#else
  std::unique_ptr<QgsLineString> segmentizedLine( curve->curveToLine() );
  QgsPointSequence points;
  segmentizedLine->points( points );
  Qgis::GeometryOperationResult result = splitGeometry( points, newGeometries, topological, topologyTestPoints, splitFeature );
 
  if ( result == Qgis::GeometryOperationResult::Success )
  {
    if ( preserveCircular )
    {
      for ( int i = 0; i < newGeometries.count(); ++i )
        newGeometries[i] = newGeometries[i].convertToCurves();
      *this = convertToCurves();
    }
  }
  return result;
#endif
}
 
Qgis::GeometryOperationResult QgsGeometry::reshapeGeometry( const QgsLineString &reshapeLineString )
{
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  }
 
  // We're trying adding the reshape line's vertices to the geometry so that
  // snap to segment always produces a valid reshape
  QgsPointSequence reshapePoints;
  reshapeLineString.points( reshapePoints );
  QgsGeometry tmpGeom( *this );
  QgsPointSequence addedTopologicalPoints;
  for ( const QgsPoint &v : std::as_const( reshapePoints ) )
  {
    // TODO: Remove this if block when reshape gets curve support, i.e.,
    // when adapted to GEOS 3.15, since GEOS does the right thing.
    if ( tmpGeom.addTopologicalPoint( v ) )
    {
      // When reshaping 3D lines or polygons we want to make sure that any topological points added
      // are preserved in the final geometry. GEOS will interpolate between geometry and reshapeLineString
      // and may create duplicate vertices with different Z values. We will manually snap Z to those topo
      // points later and remove any duplicated vertices.
      if ( tmpGeom.constGet()->is3D() )
      {
        QgsVertexId vId;
        const QgsPoint topoPoint = QgsGeometryUtils::closestVertex( *tmpGeom.constGet(), v, vId );
        addedTopologicalPoints.append( topoPoint );
      }
    }
  }
 
  QgsGeos geos( tmpGeom.get() );
  QgsGeometryEngine::EngineOperationResult errorCode = QgsGeometryEngine::Success;
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > geom( geos.reshapeGeometry( reshapeLineString, &errorCode, &mLastError ) );
  if ( errorCode == QgsGeometryEngine::Success && geom )
  {
    // TODO: Remove this inner if block when reshape gets curve support,
    // i.e., when adapted to GEOS 3.15, since GEOS does the right thing.
    if ( !addedTopologicalPoints.isEmpty() )
    {
      removeDuplicateAdjacentPointsAt( geom.get(), addedTopologicalPoints );
    }
    reset( std::move( geom ) );
    return Qgis::GeometryOperationResult::Success;
  }
 
  switch ( errorCode )
  {
    case QgsGeometryEngine::Success:
      return Qgis::GeometryOperationResult::Success;
    case QgsGeometryEngine::MethodNotImplemented:
    case QgsGeometryEngine::EngineError:
    case QgsGeometryEngine::NodedGeometryError:
      return Qgis::GeometryOperationResult::GeometryEngineError;
    case QgsGeometryEngine::InvalidBaseGeometry:
      return Qgis::GeometryOperationResult::InvalidBaseGeometry;
    case QgsGeometryEngine::InvalidInput:
      return Qgis::GeometryOperationResult::InvalidInputGeometryType;
    case QgsGeometryEngine::SplitCannotSplitPoint: // should not happen
      return Qgis::GeometryOperationResult::GeometryEngineError;
    case QgsGeometryEngine::NothingHappened:
      return Qgis::GeometryOperationResult::NothingHappened;
  }
 
  // should not be reached
  return Qgis::GeometryOperationResult::GeometryEngineError;
}
 
int QgsGeometry::makeDifferenceInPlace( const QgsGeometry &other, QgsFeedback *feedback )
{
  if ( !d->geometry || !other.d->geometry )
  {
    return 0;
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > diffGeom( geos.difference( other.constGet(), &mLastError, QgsGeometryParameters(), feedback ) );
  if ( !diffGeom )
  {
    return 1;
  }
 
  reset( std::move( diffGeom ) );
  return 0;
}
 
QgsGeometry QgsGeometry::makeDifference( const QgsGeometry &other, QgsFeedback *feedback ) const
{
  return difference( other, QgsGeometryParameters(), feedback );
}
 
QgsRectangle QgsGeometry::boundingBox() const
{
  if ( d->geometry )
  {
    return d->geometry->boundingBox();
  }
  return QgsRectangle();
}
 
QgsBox3D QgsGeometry::boundingBox3D() const
{
  if ( d->geometry )
  {
    return d->geometry->boundingBox3D();
  }
  return QgsBox3D();
}
 
 
QgsGeometry QgsGeometry::orientedMinimumBoundingBox( double &area, double &angle, double &width, double &height ) const
{
  mLastError.clear();
 
  if ( isNull() )
    return QgsGeometry();
 
  if ( type() == Qgis::GeometryType::Point && d->geometry->partCount() == 1 )
  {
    area = 0;
    angle = 0;
    width = 0;
    height = 0;
    return QgsGeometry::fromRect( d->geometry->boundingBox() );
  }
 
  QgsInternalGeometryEngine engine( *this );
  const QgsGeometry res = engine.orientedMinimumBoundingBox( area, angle, width, height );
  if ( res.isNull() )
    mLastError = engine.lastError();
  return res;
}
 
QgsGeometry QgsGeometry::orientedMinimumBoundingBox() const
{
  double area, angle, width, height;
  return orientedMinimumBoundingBox( area, angle, width, height );
}
 
static QgsCircle __recMinimalEnclosingCircle( QgsMultiPointXY points, QgsMultiPointXY boundary )
{
  auto l_boundary = boundary.length();
  QgsCircle circ_mec;
  if ( ( points.length() == 0 ) || ( l_boundary == 3 ) )
  {
    switch ( l_boundary )
    {
      case 0:
        circ_mec = QgsCircle();
        break;
      case 1:
        circ_mec = QgsCircle( QgsPoint( boundary.last() ), 0 );
        boundary.pop_back();
        break;
      case 2:
      {
        QgsPointXY p1 = boundary.last();
        boundary.pop_back();
        QgsPointXY p2 = boundary.last();
        boundary.pop_back();
        circ_mec = QgsCircle::from2Points( QgsPoint( p1 ), QgsPoint( p2 ) );
      }
      break;
      default:
        QgsPoint p1( boundary.at( 0 ) );
        QgsPoint p2( boundary.at( 1 ) );
        QgsPoint p3( boundary.at( 2 ) );
        circ_mec = QgsCircle::minimalCircleFrom3Points( p1, p2, p3 );
        break;
    }
    return circ_mec;
  }
  else
  {
    QgsPointXY pxy = points.last();
    points.pop_back();
    circ_mec = __recMinimalEnclosingCircle( points, boundary );
    QgsPoint p( pxy );
    if ( !circ_mec.contains( p ) )
    {
      boundary.append( pxy );
      circ_mec = __recMinimalEnclosingCircle( points, boundary );
    }
  }
  return circ_mec;
}
 
QgsGeometry QgsGeometry::minimalEnclosingCircle( QgsPointXY &center, double &radius, unsigned int segments ) const
{
  center = QgsPointXY();
  radius = 0;
 
  if ( isEmpty() )
  {
    return QgsGeometry();
  }
 
  /* optimization */
  QgsGeometry hull = convexHull();
  if ( hull.isNull() )
    return QgsGeometry();
 
  QgsMultiPointXY P = hull.convertToPoint( true ).asMultiPoint();
  QgsMultiPointXY R;
 
  QgsCircle circ = __recMinimalEnclosingCircle( P, R );
  center = QgsPointXY( circ.center() );
  radius = circ.radius();
  QgsGeometry geom;
  geom.set( circ.toPolygon( segments ) );
  return geom;
}
 
QgsGeometry QgsGeometry::minimalEnclosingCircle( unsigned int segments ) const
{
  QgsPointXY center;
  double radius;
  return minimalEnclosingCircle( center, radius, segments );
}
 
QgsGeometry QgsGeometry::orthogonalize( double tolerance, int maxIterations, double angleThreshold ) const
{
  QgsInternalGeometryEngine engine( *this );
 
  return engine.orthogonalize( tolerance, maxIterations, angleThreshold );
}
 
QgsGeometry QgsGeometry::triangularWaves( double wavelength, double amplitude, bool strictWavelength ) const
{
  QgsInternalGeometryEngine engine( *this );
  return engine.triangularWaves( wavelength, amplitude, strictWavelength );
}
 
QgsGeometry QgsGeometry::triangularWavesRandomized( double minimumWavelength, double maximumWavelength, double minimumAmplitude, double maximumAmplitude, unsigned long seed ) const
{
  QgsInternalGeometryEngine engine( *this );
  return engine.triangularWavesRandomized( minimumWavelength, maximumWavelength, minimumAmplitude, maximumAmplitude, seed );
}
 
QgsGeometry QgsGeometry::squareWaves( double wavelength, double amplitude, bool strictWavelength ) const
{
  QgsInternalGeometryEngine engine( *this );
  return engine.squareWaves( wavelength, amplitude, strictWavelength );
}
 
QgsGeometry QgsGeometry::squareWavesRandomized( double minimumWavelength, double maximumWavelength, double minimumAmplitude, double maximumAmplitude, unsigned long seed ) const
{
  QgsInternalGeometryEngine engine( *this );
  return engine.squareWavesRandomized( minimumWavelength, maximumWavelength, minimumAmplitude, maximumAmplitude, seed );
}
 
QgsGeometry QgsGeometry::roundWaves( double wavelength, double amplitude, bool strictWavelength ) const
{
  QgsInternalGeometryEngine engine( *this );
  return engine.roundWaves( wavelength, amplitude, strictWavelength );
}
 
QgsGeometry QgsGeometry::roundWavesRandomized( double minimumWavelength, double maximumWavelength, double minimumAmplitude, double maximumAmplitude, unsigned long seed ) const
{
  QgsInternalGeometryEngine engine( *this );
  return engine.roundWavesRandomized( minimumWavelength, maximumWavelength, minimumAmplitude, maximumAmplitude, seed );
}
 
QgsGeometry QgsGeometry::applyDashPattern(
  const QVector<double> &pattern, Qgis::DashPatternLineEndingRule startRule, Qgis::DashPatternLineEndingRule endRule, Qgis::DashPatternSizeAdjustment adjustment, double patternOffset
) const
{
  QgsInternalGeometryEngine engine( *this );
  return engine.applyDashPattern( pattern, startRule, endRule, adjustment, patternOffset );
}
 
QgsGeometry QgsGeometry::snappedToGrid( double hSpacing, double vSpacing, double dSpacing, double mSpacing ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
  return QgsGeometry( d->geometry->snappedToGrid( hSpacing, vSpacing, dSpacing, mSpacing ) );
}
 
bool QgsGeometry::removeDuplicateNodes( double epsilon, bool useZValues )
{
  if ( !d->geometry )
    return false;
 
  detach();
  return d->geometry->removeDuplicateNodes( epsilon, useZValues );
}
 
bool QgsGeometry::intersects( const QgsRectangle &r ) const
{
  // fast case, check bounding boxes
  if ( !boundingBoxIntersects( r ) )
    return false;
 
  const Qgis::WkbType flatType { QgsWkbTypes::flatType( d->geometry->wkbType() ) };
  // optimise trivial case for point intersections -- the bounding box test has already given us the answer
  if ( flatType == Qgis::WkbType::Point )
  {
    return true;
  }
 
#if GEOS_VERSION_NUM < GEOS_COMPUTE_VERSION( 3, 12, 0 )
  // Workaround for issue issue GH #51492
  // in case of multi polygon, intersection with an empty rect fails
  if ( flatType == Qgis::WkbType::MultiPolygon && r.isEmpty() )
  {
    const QgsPointXY center { r.xMinimum(), r.yMinimum() };
    return contains( QgsGeometry::fromPointXY( center ) );
  }
#endif
 
  QgsGeometry g = fromRect( r );
  return intersects( g );
}
 
bool QgsGeometry::intersects( const QgsGeometry &geometry ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.intersects( geometry.d->geometry.get(), &mLastError );
}
 
bool QgsGeometry::boundingBoxIntersects( const QgsRectangle &rectangle ) const
{
  if ( !d->geometry )
  {
    return false;
  }
 
  return d->geometry->boundingBoxIntersects( rectangle );
}
 
bool QgsGeometry::boundingBoxIntersects( const QgsGeometry &geometry ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return false;
  }
 
  return d->geometry->boundingBoxIntersects( geometry.constGet()->boundingBox() );
}
 
bool QgsGeometry::contains( const QgsPointXY *p ) const
{
  if ( !d->geometry || !p )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.contains( p->x(), p->y(), &mLastError );
}
 
bool QgsGeometry::contains( double x, double y ) const
{
  if ( !d->geometry )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.contains( x, y, &mLastError );
}
 
bool QgsGeometry::contains( const QgsGeometry &geometry ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.contains( geometry.d->geometry.get(), &mLastError );
}
 
bool QgsGeometry::disjoint( const QgsGeometry &geometry ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.disjoint( geometry.d->geometry.get(), &mLastError );
}
 
bool QgsGeometry::equals( const QgsGeometry &geometry ) const
{
  return isExactlyEqual( geometry );
}
 
bool QgsGeometry::touches( const QgsGeometry &geometry ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.touches( geometry.d->geometry.get(), &mLastError );
}
 
bool QgsGeometry::overlaps( const QgsGeometry &geometry ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.overlaps( geometry.d->geometry.get(), &mLastError );
}
 
bool QgsGeometry::within( const QgsGeometry &geometry ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.within( geometry.d->geometry.get(), &mLastError );
}
 
bool QgsGeometry::crosses( const QgsGeometry &geometry ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return false;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.crosses( geometry.d->geometry.get(), &mLastError );
}
 
QString QgsGeometry::asWkt( int precision ) const
{
  if ( !d->geometry )
  {
    return QString();
  }
  return d->geometry->asWkt( precision );
}
 
QString QgsGeometry::asJson( int precision ) const
{
  return asGeoJson( precision, Qgis::GeoJsonProfile::Rfc7946 );
}
 
QString QgsGeometry::asGeoJson( int precision, Qgis::GeoJsonProfile profile ) const
{
  return QString::fromStdString( asJsonObject( precision, profile ).dump() );
}
 
json QgsGeometry::asJsonObject( int precision, Qgis::GeoJsonProfile profile ) const
{
  if ( !d->geometry )
  {
    return nullptr;
  }
  return d->geometry->asJsonObject( precision, profile );
}
 
QVector<QgsGeometry> QgsGeometry::coerceToType( const Qgis::WkbType type, double defaultZ, double defaultM, bool avoidDuplicates ) const
{
  mLastError.clear();
  QVector< QgsGeometry > res;
  if ( isNull() )
    return res;
 
  if ( wkbType() == type || type == Qgis::WkbType::Unknown )
  {
    res << *this;
    return res;
  }
 
  if ( type == Qgis::WkbType::NoGeometry )
  {
    return res;
  }
 
  QgsGeometry newGeom = *this;
 
  // Curved -> straight
  if ( !QgsWkbTypes::isCurvedType( type ) && QgsWkbTypes::isCurvedType( newGeom.wkbType() ) )
  {
    newGeom = QgsGeometry( d->geometry.get()->segmentize() );
  }
 
  // Handle NurbsCurve: if target is curved but NOT NurbsCurve, and source contains NurbsCurve,
  // we need to segmentize the NURBS parts first
  if ( QgsWkbTypes::isCurvedType( type ) && !QgsWkbTypes::isNurbsType( type ) )
  {
    // Check if geometry contains NurbsCurve that needs conversion
    bool hasNurbs = false;
    if ( QgsWkbTypes::isNurbsType( newGeom.wkbType() ) )
    {
      hasNurbs = true;
    }
    else if ( const QgsGeometryCollection *collection = qgsgeometry_cast< const QgsGeometryCollection * >( newGeom.constGet() ) )
    {
      for ( int i = 0; i < collection->numGeometries(); ++i )
      {
        if ( QgsWkbTypes::isNurbsType( collection->geometryN( i )->wkbType() ) )
        {
          hasNurbs = true;
          break;
        }
      }
    }
    else if ( const QgsCurvePolygon *cp = qgsgeometry_cast< const QgsCurvePolygon * >( newGeom.constGet() ) )
    {
      if ( cp->exteriorRing() && QgsWkbTypes::isNurbsType( cp->exteriorRing()->wkbType() ) )
        hasNurbs = true;
      for ( int i = 0; !hasNurbs && i < cp->numInteriorRings(); ++i )
      {
        if ( QgsWkbTypes::isNurbsType( cp->interiorRing( i )->wkbType() ) )
          hasNurbs = true;
      }
    }
    else if ( const QgsCompoundCurve *cc = qgsgeometry_cast< const QgsCompoundCurve * >( newGeom.constGet() ) )
    {
      for ( int i = 0; i < cc->nCurves(); ++i )
      {
        if ( QgsWkbTypes::isNurbsType( cc->curveAt( i )->wkbType() ) )
        {
          hasNurbs = true;
          break;
        }
      }
    }
 
    if ( hasNurbs )
    {
      // Segmentize to remove NURBS, then we'll convert back to curve type below
      newGeom = QgsGeometry( newGeom.constGet()->segmentize() );
    }
  }
 
  // polygon -> line
  if ( QgsWkbTypes::geometryType( type ) == Qgis::GeometryType::Line && newGeom.type() == Qgis::GeometryType::Polygon )
  {
    // boundary gives us a (multi)line string of exterior + interior rings
    newGeom = QgsGeometry( newGeom.constGet()->boundary() );
  }
  // line -> polygon
  if ( QgsWkbTypes::geometryType( type ) == Qgis::GeometryType::Polygon && newGeom.type() == Qgis::GeometryType::Line )
  {
    std::unique_ptr< QgsGeometryCollection > gc( QgsGeometryFactory::createCollectionOfType( type ) );
    const QgsGeometry source = newGeom;
    for ( auto part = source.const_parts_begin(); part != source.const_parts_end(); ++part )
    {
      std::unique_ptr< QgsAbstractGeometry > exterior( ( *part )->clone() );
      if ( QgsCurve *curve = qgsgeometry_cast< QgsCurve * >( exterior.get() ) )
      {
        if ( QgsWkbTypes::isCurvedType( type ) )
        {
          auto cp = std::make_unique< QgsCurvePolygon >();
          cp->setExteriorRing( curve );
          ( void ) exterior.release();
          gc->addGeometry( cp.release() );
        }
        else
        {
          auto p = std::make_unique< QgsPolygon >();
          p->setExteriorRing( qgsgeometry_cast< QgsLineString * >( curve ) );
          ( void ) exterior.release();
          gc->addGeometry( p.release() );
        }
      }
    }
    newGeom = QgsGeometry( std::move( gc ) );
  }
 
  // line/polygon -> points
  if ( QgsWkbTypes::geometryType( type ) == Qgis::GeometryType::Point && ( newGeom.type() == Qgis::GeometryType::Line || newGeom.type() == Qgis::GeometryType::Polygon ) )
  {
    // lines/polygons to a point layer, extract all vertices
    auto mp = std::make_unique< QgsMultiPoint >();
    const QgsGeometry source = newGeom;
    QSet< QgsPoint > added;
    for ( auto vertex = source.vertices_begin(); vertex != source.vertices_end(); ++vertex )
    {
      if ( avoidDuplicates && added.contains( *vertex ) )
        continue; // avoid duplicate points, e.g. start/end of rings
      mp->addGeometry( ( *vertex ).clone() );
      added.insert( *vertex );
    }
    newGeom = QgsGeometry( std::move( mp ) );
  }
 
  //(Multi)Polygon to PolyhedralSurface
  if ( QgsWkbTypes::flatType( type ) == Qgis::WkbType::PolyhedralSurface && QgsWkbTypes::flatType( QgsWkbTypes::singleType( newGeom.wkbType() ) ) == Qgis::WkbType::Polygon )
  {
    auto polySurface = std::make_unique< QgsPolyhedralSurface >();
    const QgsGeometry source = newGeom;
    for ( auto part = source.const_parts_begin(); part != source.const_parts_end(); ++part )
    {
      if ( const QgsPolygon *polygon = qgsgeometry_cast< const QgsPolygon * >( *part ) )
      {
        polySurface->addPatch( polygon->clone() );
      }
    }
    newGeom = QgsGeometry( std::move( polySurface ) );
  }
 
  //(Multi)Polygon/Triangle to TIN
  if ( QgsWkbTypes::flatType( type ) == Qgis::WkbType::TIN
       && ( QgsWkbTypes::flatType( QgsWkbTypes::singleType( newGeom.wkbType() ) ) == Qgis::WkbType::Polygon || QgsWkbTypes::flatType( QgsWkbTypes::singleType( newGeom.wkbType() ) ) == Qgis::WkbType::Triangle ) )
  {
    auto tin = std::make_unique< QgsTriangulatedSurface >();
    const QgsGeometry source = newGeom;
    for ( auto part = source.const_parts_begin(); part != source.const_parts_end(); ++part )
    {
      if ( const QgsTriangle *triangle = qgsgeometry_cast< const QgsTriangle * >( *part ) )
      {
        tin->addPatch( triangle->clone() );
      }
      else if ( const QgsPolygon *polygon = qgsgeometry_cast< const QgsPolygon * >( *part ) )
      {
        // Validate that the polygon can be converted to a triangle (must have exactly 3 vertices + closing point)
        if ( polygon->exteriorRing() )
        {
          const int numPoints = polygon->exteriorRing()->numPoints();
          if ( numPoints != 4 )
          {
            mLastError = QObject::tr( "Cannot convert polygon with %1 vertices to a triangle. A triangle requires exactly 3 vertices." ).arg( numPoints > 0 ? numPoints - 1 : 0 );
            return res;
          }
          auto triangle = std::make_unique< QgsTriangle >();
          triangle->setExteriorRing( polygon->exteriorRing()->clone() );
          tin->addPatch( triangle.release() );
        }
      }
    }
    newGeom = QgsGeometry( std::move( tin ) );
  }
 
  // PolyhedralSurface/TIN to (Multi)Polygon
  if ( QgsWkbTypes::flatType( QgsWkbTypes::singleType( type ) ) == Qgis::WkbType::Polygon
       && ( QgsWkbTypes::flatType( newGeom.wkbType() ) == Qgis::WkbType::PolyhedralSurface || QgsWkbTypes::flatType( newGeom.wkbType() ) == Qgis::WkbType::TIN ) )
  {
    auto multiPolygon = std::make_unique< QgsMultiPolygon >();
    if ( const QgsPolyhedralSurface *polySurface = qgsgeometry_cast< const QgsPolyhedralSurface * >( newGeom.constGet() ) )
    {
      for ( int i = 0; i < polySurface->numPatches(); ++i )
      {
        const QgsPolygon *patch = polySurface->patchN( i );
        auto polygon = std::make_unique< QgsPolygon >();
        polygon->setExteriorRing( patch->exteriorRing()->clone() );
        for ( int j = 0; j < patch->numInteriorRings(); ++j )
        {
          polygon->addInteriorRing( patch->interiorRing( j )->clone() );
        }
        multiPolygon->addGeometry( polygon.release() );
      }
    }
    newGeom = QgsGeometry( std::move( multiPolygon ) );
  }
 
  // Polygon -> Triangle
  if ( QgsWkbTypes::flatType( type ) == Qgis::WkbType::Triangle && QgsWkbTypes::flatType( newGeom.wkbType() ) == Qgis::WkbType::Polygon )
  {
    if ( const QgsPolygon *polygon = qgsgeometry_cast< const QgsPolygon * >( newGeom.constGet() ) )
    {
      // Validate that the polygon can be converted to a triangle (must have exactly 3 vertices + closing point)
      if ( polygon->exteriorRing() )
      {
        const int numPoints = polygon->exteriorRing()->numPoints();
        if ( numPoints != 4 )
        {
          mLastError = QObject::tr( "Cannot convert polygon with %1 vertices to a triangle. A triangle requires exactly 3 vertices." ).arg( numPoints > 0 ? numPoints - 1 : 0 );
          return res;
        }
        auto triangle = std::make_unique< QgsTriangle >();
        triangle->setExteriorRing( polygon->exteriorRing()->clone() );
        newGeom = QgsGeometry( std::move( triangle ) );
      }
    }
  }
 
 
  // Single -> multi
  if ( QgsWkbTypes::isMultiType( type ) && !newGeom.isMultipart() )
  {
    newGeom.convertToMultiType();
  }
  // Drop Z/M
  if ( newGeom.constGet()->is3D() && !QgsWkbTypes::hasZ( type ) )
  {
    newGeom.get()->dropZValue();
  }
  if ( newGeom.constGet()->isMeasure() && !QgsWkbTypes::hasM( type ) )
  {
    newGeom.get()->dropMValue();
  }
  // Add Z/M back, set to 0
  if ( !newGeom.constGet()->is3D() && QgsWkbTypes::hasZ( type ) )
  {
    newGeom.get()->addZValue( defaultZ );
  }
  if ( !newGeom.constGet()->isMeasure() && QgsWkbTypes::hasM( type ) )
  {
    newGeom.get()->addMValue( defaultM );
  }
 
  // Straight -> curve
  if ( QgsWkbTypes::isCurvedType( type ) && !QgsWkbTypes::isCurvedType( newGeom.wkbType() ) )
  {
    newGeom.convertToCurvedMultiType();
  }
 
  // Multi -> single
  if ( !QgsWkbTypes::isMultiType( type ) && newGeom.isMultipart() )
  {
    const QgsGeometryCollection *parts( static_cast< const QgsGeometryCollection * >( newGeom.constGet() ) );
    res.reserve( parts->partCount() );
    for ( int i = 0; i < parts->partCount(); i++ )
    {
      const QgsAbstractGeometry *part = parts->geometryN( i );
      if ( QgsWkbTypes::isCurvedType( type ) && !QgsWkbTypes::isCurvedType( part->wkbType() ) )
        res << QgsGeometry( part->toCurveType() );
      else
        res << QgsGeometry( part->clone() );
    }
  }
  // GeometryCollection (of Point/LineString/Polygon) -> MultiPoint/MultiLineString/MultiPolygon
  else if ( ( type == Qgis::WkbType::MultiPoint || type == Qgis::WkbType::MultiLineString || type == Qgis::WkbType::MultiPolygon ) && newGeom.wkbType() == Qgis::WkbType::GeometryCollection )
  {
    Qgis::WkbType singleType = QgsWkbTypes::singleType( type );
    const QgsGeometryCollection *geomColl( static_cast< const QgsGeometryCollection * >( newGeom.constGet() ) );
 
    bool allExpectedType = true;
    for ( int i = 0; i < geomColl->numGeometries(); ++i )
    {
      if ( geomColl->geometryN( i )->wkbType() != singleType )
      {
        allExpectedType = false;
        break;
      }
    }
    if ( allExpectedType )
    {
      std::unique_ptr< QgsGeometryCollection > newGeomCol;
      if ( type == Qgis::WkbType::MultiPoint )
      {
        newGeomCol = std::make_unique< QgsMultiPoint >();
      }
      else if ( type == Qgis::WkbType::MultiLineString )
      {
        newGeomCol = std::make_unique< QgsMultiLineString >();
      }
      else
      {
        newGeomCol = std::make_unique< QgsMultiPolygon >();
      }
      newGeomCol->reserve( geomColl->numGeometries() );
      for ( int i = 0; i < geomColl->numGeometries(); ++i )
      {
        newGeomCol->addGeometry( geomColl->geometryN( i )->clone() );
      }
      res << QgsGeometry( std::move( newGeomCol ) );
    }
    else
    {
      res << newGeom;
    }
  }
  else
  {
    res << newGeom;
  }
  return res;
}
 
QgsGeometry QgsGeometry::convertToType( Qgis::GeometryType destType, bool destMultipart ) const
{
  switch ( destType )
  {
    case Qgis::GeometryType::Point:
      return convertToPoint( destMultipart );
 
    case Qgis::GeometryType::Line:
      return convertToLine( destMultipart );
 
    case Qgis::GeometryType::Polygon:
      return convertToPolygon( destMultipart );
 
    default:
      return QgsGeometry();
  }
}
 
bool QgsGeometry::convertToMultiType()
{
  if ( !d->geometry )
  {
    return false;
  }
 
  if ( isMultipart() ) //already multitype, no need to convert
  {
    return true;
  }
 
  std::unique_ptr< QgsAbstractGeometry > geom = QgsGeometryFactory::geomFromWkbType( QgsWkbTypes::multiType( d->geometry->wkbType() ) );
  QgsGeometryCollection *multiGeom = qgsgeometry_cast<QgsGeometryCollection *>( geom.get() );
  if ( !multiGeom )
  {
    return false;
  }
 
  //try to avoid cloning existing geometry whenever we can
 
  //want to see a magic trick?... gather round kiddies...
  detach(); // maybe a clone, hopefully not if we're the only ref to the private data
  // now we cheat a bit and steal the private geometry and add it direct to the multigeom
  // we can do this because we're the only ref to this geometry, guaranteed by the detach call above
  multiGeom->addGeometry( d->geometry.release() );
  // and replace it with the multi geometry.
  // TADA! a clone free conversion in some cases
  d->geometry = std::move( geom );
  return true;
}
 
bool QgsGeometry::convertToCurvedMultiType()
{
  if ( !d->geometry )
  {
    return false;
  }
 
  switch ( QgsWkbTypes::flatType( d->geometry->wkbType() ) )
  {
    case Qgis::WkbType::MultiPoint:
    case Qgis::WkbType::MultiCurve:
    case Qgis::WkbType::MultiSurface:
    case Qgis::WkbType::GeometryCollection:
    {
      return true;
    }
    default:
      break;
  }
 
  std::unique_ptr< QgsAbstractGeometry > geom = QgsGeometryFactory::geomFromWkbType( QgsWkbTypes::curveType( QgsWkbTypes::multiType( d->geometry->wkbType() ) ) );
  QgsGeometryCollection *multiGeom = qgsgeometry_cast<QgsGeometryCollection *>( geom.get() );
  if ( !multiGeom )
  {
    return false;
  }
 
  QgsGeometryCollection *sourceMultiGeom = qgsgeometry_cast<QgsGeometryCollection *>( d->geometry.get() );
  if ( sourceMultiGeom )
  {
    for ( int i = 0; i < sourceMultiGeom->numGeometries(); ++i )
    {
      if ( !multiGeom->addGeometry( sourceMultiGeom->geometryN( i )->clone() ) )
        return false;
    }
  }
  else
  {
    if ( !multiGeom->addGeometry( d->geometry->clone() ) )
      return false;
  }
 
  reset( std::move( geom ) );
  return true;
}
 
bool QgsGeometry::convertToSingleType()
{
  if ( !d->geometry )
  {
    return false;
  }
 
  if ( !isMultipart() ) //already single part, no need to convert
  {
    return true;
  }
 
  QgsGeometryCollection *multiGeom = qgsgeometry_cast<QgsGeometryCollection *>( d->geometry.get() );
  if ( !multiGeom || multiGeom->partCount() < 1 )
    return false;
 
  std::unique_ptr< QgsAbstractGeometry > firstPart( multiGeom->geometryN( 0 )->clone() );
  reset( std::move( firstPart ) );
  return true;
}
 
 
bool QgsGeometry::convertGeometryCollectionToSubclass( Qgis::GeometryType geomType )
{
  const QgsGeometryCollection *origGeom = qgsgeometry_cast<const QgsGeometryCollection *>( constGet() );
  if ( !origGeom )
    return false;
 
  std::unique_ptr<QgsGeometryCollection> resGeom;
  switch ( geomType )
  {
    case Qgis::GeometryType::Point:
      resGeom = std::make_unique<QgsMultiPoint>();
      break;
    case Qgis::GeometryType::Line:
      resGeom = std::make_unique<QgsMultiLineString>();
      break;
    case Qgis::GeometryType::Polygon:
      resGeom = std::make_unique<QgsMultiPolygon>();
      break;
    default:
      break;
  }
  if ( !resGeom )
    return false;
 
  resGeom->reserve( origGeom->numGeometries() );
  for ( int i = 0; i < origGeom->numGeometries(); ++i )
  {
    const QgsAbstractGeometry *g = origGeom->geometryN( i );
    if ( QgsWkbTypes::geometryType( g->wkbType() ) == geomType )
      resGeom->addGeometry( g->clone() );
  }
 
  set( resGeom.release() );
  return true;
}
 
 
QgsPointXY QgsGeometry::asPoint() const
{
  if ( !d->geometry )
  {
    return QgsPointXY();
  }
  if ( const QgsPoint *pt = qgsgeometry_cast<const QgsPoint *>( d->geometry->simplifiedTypeRef() ) )
  {
    return QgsPointXY( pt->x(), pt->y() );
  }
  else
  {
    return QgsPointXY();
  }
}
 
QgsPolylineXY QgsGeometry::asPolyline() const
{
  QgsPolylineXY polyLine;
  if ( !d->geometry )
  {
    return polyLine;
  }
 
  bool doSegmentation = ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::CompoundCurve || QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::CircularString );
  std::unique_ptr< QgsLineString > segmentizedLine;
  QgsLineString *line = nullptr;
  if ( doSegmentation )
  {
    QgsCurve *curve = qgsgeometry_cast<QgsCurve *>( d->geometry.get() );
    if ( !curve )
    {
      return polyLine;
    }
    segmentizedLine.reset( curve->curveToLine() );
    line = segmentizedLine.get();
  }
  else
  {
    line = qgsgeometry_cast<QgsLineString *>( d->geometry.get() );
    if ( !line )
    {
      return polyLine;
    }
  }
 
  int nVertices = line->numPoints();
  polyLine.resize( nVertices );
  QgsPointXY *data = polyLine.data();
  const double *xData = line->xData();
  const double *yData = line->yData();
  for ( int i = 0; i < nVertices; ++i )
  {
    data->setX( *xData++ );
    data->setY( *yData++ );
    data++;
  }
 
  return polyLine;
}
 
QgsPolygonXY QgsGeometry::asPolygon() const
{
  if ( !d->geometry )
    return QgsPolygonXY();
 
  bool doSegmentation = ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::CurvePolygon );
 
  QgsPolygon *p = nullptr;
  std::unique_ptr< QgsPolygon > segmentized;
  if ( doSegmentation )
  {
    QgsCurvePolygon *curvePoly = qgsgeometry_cast<QgsCurvePolygon *>( d->geometry.get() );
    if ( !curvePoly )
    {
      return QgsPolygonXY();
    }
    segmentized.reset( curvePoly->toPolygon() );
    p = segmentized.get();
  }
  else
  {
    p = qgsgeometry_cast<QgsPolygon *>( d->geometry.get() );
  }
 
  if ( !p )
  {
    return QgsPolygonXY();
  }
 
  QgsPolygonXY polygon;
  convertPolygon( *p, polygon );
 
  return polygon;
}
 
QgsMultiPointXY QgsGeometry::asMultiPoint() const
{
  if ( !d->geometry || QgsWkbTypes::flatType( d->geometry->wkbType() ) != Qgis::WkbType::MultiPoint )
  {
    return QgsMultiPointXY();
  }
 
  const QgsMultiPoint *mp = qgsgeometry_cast<QgsMultiPoint *>( d->geometry.get() );
  if ( !mp )
  {
    return QgsMultiPointXY();
  }
 
  int nPoints = mp->numGeometries();
  QgsMultiPointXY multiPoint( nPoints );
  for ( int i = 0; i < nPoints; ++i )
  {
    const QgsPoint *pt = mp->pointN( i );
    multiPoint[i].setX( pt->x() );
    multiPoint[i].setY( pt->y() );
  }
  return multiPoint;
}
 
QgsMultiPolylineXY QgsGeometry::asMultiPolyline() const
{
  if ( !d->geometry )
  {
    return QgsMultiPolylineXY();
  }
 
  QgsGeometryCollection *geomCollection = qgsgeometry_cast<QgsGeometryCollection *>( d->geometry.get() );
  if ( !geomCollection )
  {
    return QgsMultiPolylineXY();
  }
 
  int nLines = geomCollection->numGeometries();
  if ( nLines < 1 )
  {
    return QgsMultiPolylineXY();
  }
 
  QgsMultiPolylineXY mpl;
  mpl.reserve( nLines );
  for ( int i = 0; i < nLines; ++i )
  {
    const QgsLineString *line = qgsgeometry_cast<const QgsLineString *>( geomCollection->geometryN( i ) );
    std::unique_ptr< QgsLineString > segmentized;
    if ( !line )
    {
      const QgsCurve *curve = qgsgeometry_cast<const QgsCurve *>( geomCollection->geometryN( i ) );
      if ( !curve )
      {
        continue;
      }
      segmentized.reset( curve->curveToLine() );
      line = segmentized.get();
    }
 
    QgsPolylineXY polyLine;
    int nVertices = line->numPoints();
    polyLine.resize( nVertices );
    QgsPointXY *data = polyLine.data();
    const double *xData = line->xData();
    const double *yData = line->yData();
    for ( int i = 0; i < nVertices; ++i )
    {
      data->setX( *xData++ );
      data->setY( *yData++ );
      data++;
    }
    mpl.append( polyLine );
  }
  return mpl;
}
 
QgsMultiPolygonXY QgsGeometry::asMultiPolygon() const
{
  if ( !d->geometry )
  {
    return QgsMultiPolygonXY();
  }
 
  const QgsGeometryCollection *geomCollection = qgsgeometry_cast<const QgsGeometryCollection *>( d->geometry.get() );
  if ( !geomCollection )
  {
    return QgsMultiPolygonXY();
  }
 
  const int nPolygons = geomCollection->numGeometries();
  if ( nPolygons < 1 )
  {
    return QgsMultiPolygonXY();
  }
 
  QgsMultiPolygonXY mp;
  mp.reserve( nPolygons );
  for ( int i = 0; i < nPolygons; ++i )
  {
    const QgsPolygon *polygon = qgsgeometry_cast<const QgsPolygon *>( geomCollection->geometryN( i ) );
    if ( !polygon )
    {
      const QgsCurvePolygon *cPolygon = qgsgeometry_cast<const QgsCurvePolygon *>( geomCollection->geometryN( i ) );
      if ( cPolygon )
      {
        polygon = cPolygon->toPolygon();
      }
      else
      {
        continue;
      }
    }
 
    QgsPolygonXY poly;
    convertPolygon( *polygon, poly );
    mp.push_back( poly );
  }
  return mp;
}
 
double QgsGeometry::area() const
{
  if ( !d->geometry )
  {
    return -1.0;
  }
 
  return d->geometry->area();
}
 
double QgsGeometry::area3D() const
{
  if ( !d->geometry )
  {
    throw QgsInvalidArgumentException( "Cannot compute 3D area: geometry is null." );
  }
 
  return d->geometry->area3D();
}
 
double QgsGeometry::length() const
{
  if ( !d->geometry )
  {
    return -1.0;
  }
 
  switch ( QgsWkbTypes::geometryType( d->geometry->wkbType() ) )
  {
    case Qgis::GeometryType::Point:
      return 0.0;
 
    case Qgis::GeometryType::Line:
      return d->geometry->length();
 
    case Qgis::GeometryType::Polygon:
      return d->geometry->perimeter();
 
    case Qgis::GeometryType::Unknown:
    case Qgis::GeometryType::Null:
      return d->geometry->length();
  }
  return -1;
}
 
double QgsGeometry::distance( const QgsGeometry &geom ) const
{
  if ( !d->geometry || !geom.d->geometry )
  {
    return -1.0;
  }
 
  // avoid calling geos for trivial point-to-point distance calculations
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::Point && QgsWkbTypes::flatType( geom.wkbType() ) == Qgis::WkbType::Point )
  {
    return qgsgeometry_cast< const QgsPoint * >( d->geometry.get() )->distance( *qgsgeometry_cast< const QgsPoint * >( geom.constGet() ) );
  }
 
  QgsGeos g( d->geometry.get() );
  mLastError.clear();
  return g.distance( geom.d->geometry.get(), &mLastError );
}
 
double QgsGeometry::hausdorffDistance( const QgsGeometry &geom ) const
{
  if ( !d->geometry || !geom.d->geometry )
  {
    return -1.0;
  }
 
  QgsGeos g( d->geometry.get() );
  mLastError.clear();
  return g.hausdorffDistance( geom.d->geometry.get(), &mLastError );
}
 
double QgsGeometry::hausdorffDistanceDensify( const QgsGeometry &geom, double densifyFraction ) const
{
  if ( !d->geometry || !geom.d->geometry )
  {
    return -1.0;
  }
 
  QgsGeos g( d->geometry.get() );
  mLastError.clear();
  return g.hausdorffDistanceDensify( geom.d->geometry.get(), densifyFraction, &mLastError );
}
 
 
double QgsGeometry::frechetDistance( const QgsGeometry &geom ) const
{
  if ( !d->geometry || !geom.d->geometry )
  {
    return -1.0;
  }
 
  QgsGeos g( d->geometry.get() );
  mLastError.clear();
  return g.frechetDistance( geom.d->geometry.get(), &mLastError );
}
 
double QgsGeometry::frechetDistanceDensify( const QgsGeometry &geom, double densifyFraction ) const
{
  if ( !d->geometry || !geom.d->geometry )
  {
    return -1.0;
  }
 
  QgsGeos g( d->geometry.get() );
  mLastError.clear();
  return g.frechetDistanceDensify( geom.d->geometry.get(), densifyFraction, &mLastError );
}
 
QgsAbstractGeometry::vertex_iterator QgsGeometry::vertices_begin() const
{
  if ( !d->geometry || d->geometry.get()->isEmpty() )
    return QgsAbstractGeometry::vertex_iterator();
  return d->geometry->vertices_begin();
}
 
QgsAbstractGeometry::vertex_iterator QgsGeometry::vertices_end() const
{
  if ( !d->geometry || d->geometry.get()->isEmpty() )
    return QgsAbstractGeometry::vertex_iterator();
  return d->geometry->vertices_end();
}
 
QgsVertexIterator QgsGeometry::vertices() const
{
  if ( !d->geometry || d->geometry.get()->isEmpty() )
    return QgsVertexIterator();
  return QgsVertexIterator( d->geometry.get() );
}
 
QgsAbstractGeometry::part_iterator QgsGeometry::parts_begin()
{
  if ( !d->geometry )
    return QgsAbstractGeometry::part_iterator();
 
  detach();
  return d->geometry->parts_begin();
}
 
QgsAbstractGeometry::part_iterator QgsGeometry::parts_end()
{
  if ( !d->geometry )
    return QgsAbstractGeometry::part_iterator();
  return d->geometry->parts_end();
}
 
QgsAbstractGeometry::const_part_iterator QgsGeometry::const_parts_begin() const
{
  if ( !d->geometry )
    return QgsAbstractGeometry::const_part_iterator();
  return d->geometry->const_parts_begin();
}
 
QgsAbstractGeometry::const_part_iterator QgsGeometry::const_parts_end() const
{
  if ( !d->geometry )
    return QgsAbstractGeometry::const_part_iterator();
  return d->geometry->const_parts_end();
}
 
QgsGeometryPartIterator QgsGeometry::parts()
{
  if ( !d->geometry )
    return QgsGeometryPartIterator();
 
  detach();
  return QgsGeometryPartIterator( d->geometry.get() );
}
 
QgsGeometryConstPartIterator QgsGeometry::constParts() const
{
  if ( !d->geometry )
    return QgsGeometryConstPartIterator();
 
  return QgsGeometryConstPartIterator( d->geometry.get() );
}
 
QgsGeometry QgsGeometry::buffer( double distance, int segments, QgsFeedback *feedback ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos g( d->geometry.get() );
  mLastError.clear();
  std::unique_ptr<QgsAbstractGeometry> geom( g.buffer( distance, segments, &mLastError, feedback ) );
  if ( !geom )
  {
    QgsGeometry result;
    result.mLastError = mLastError;
    return result;
  }
  return QgsGeometry( std::move( geom ) );
}
 
QgsGeometry QgsGeometry::buffer( double distance, int segments, Qgis::EndCapStyle endCapStyle, Qgis::JoinStyle joinStyle, double miterLimit, QgsFeedback *feedback ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos g( d->geometry.get() );
  mLastError.clear();
  QgsAbstractGeometry *geom = g.buffer( distance, segments, endCapStyle, joinStyle, miterLimit, &mLastError, feedback );
  if ( !geom )
  {
    QgsGeometry result;
    result.mLastError = mLastError;
    return result;
  }
  return QgsGeometry( geom );
}
 
QgsGeometry QgsGeometry::offsetCurve( double distance, int segments, Qgis::JoinStyle joinStyle, double miterLimit ) const
{
  if ( !d->geometry || type() != Qgis::GeometryType::Line )
  {
    return QgsGeometry();
  }
 
  if ( QgsWkbTypes::isMultiType( d->geometry->wkbType() ) )
  {
    const QVector<QgsGeometry> parts = asGeometryCollection();
    QVector<QgsGeometry> results;
    results.reserve( parts.count() );
    for ( const QgsGeometry &part : parts )
    {
      QgsGeometry result = part.offsetCurve( distance, segments, joinStyle, miterLimit );
      if ( !result.isNull() )
        results << result;
    }
    if ( results.isEmpty() )
      return QgsGeometry();
 
    QgsGeometry first = results.takeAt( 0 );
    for ( const QgsGeometry &result : std::as_const( results ) )
    {
      first.addPart( result );
    }
    return first;
  }
  else
  {
    QgsGeos geos( d->geometry.get() );
    mLastError.clear();
 
    // GEOS can flip the curve orientation in some circumstances. So record previous orientation and correct if required
    const Qgis::AngularDirection prevOrientation = qgsgeometry_cast< const QgsCurve * >( d->geometry.get() )->orientation();
 
    std::unique_ptr< QgsAbstractGeometry > offsetGeom( geos.offsetCurve( distance, segments, joinStyle, miterLimit, &mLastError ) );
    if ( !offsetGeom )
    {
      QgsGeometry result;
      result.mLastError = mLastError;
      return result;
    }
 
    if ( const QgsCurve *offsetCurve = qgsgeometry_cast< const QgsCurve * >( offsetGeom.get() ) )
    {
      const Qgis::AngularDirection newOrientation = offsetCurve->orientation();
      if ( newOrientation != prevOrientation )
      {
        // GEOS has flipped line orientation, flip it back
        std::unique_ptr< QgsAbstractGeometry > flipped( offsetCurve->reversed() );
        offsetGeom = std::move( flipped );
      }
    }
    return QgsGeometry( std::move( offsetGeom ) );
  }
}
 
QgsGeometry QgsGeometry::singleSidedBuffer( double distance, int segments, Qgis::BufferSide side, Qgis::JoinStyle joinStyle, double miterLimit ) const
{
  if ( !d->geometry || type() != Qgis::GeometryType::Line )
  {
    return QgsGeometry();
  }
 
  if ( QgsWkbTypes::isMultiType( d->geometry->wkbType() ) )
  {
    const QVector<QgsGeometry> parts = asGeometryCollection();
    QVector<QgsGeometry> results;
    results.reserve( parts.count() );
    for ( const QgsGeometry &part : parts )
    {
      QgsGeometry result = part.singleSidedBuffer( distance, segments, side, joinStyle, miterLimit );
      if ( !result.isNull() )
        results << result;
    }
    if ( results.isEmpty() )
      return QgsGeometry();
 
    QgsGeometry first = results.takeAt( 0 );
    for ( const QgsGeometry &result : std::as_const( results ) )
    {
      first.addPart( result );
    }
    return first;
  }
  else
  {
    QgsGeos geos( d->geometry.get() );
    mLastError.clear();
    std::unique_ptr< QgsAbstractGeometry > bufferGeom = geos.singleSidedBuffer( distance, segments, side, joinStyle, miterLimit, &mLastError );
    if ( !bufferGeom )
    {
      QgsGeometry result;
      result.mLastError = mLastError;
      return result;
    }
    return QgsGeometry( std::move( bufferGeom ) );
  }
}
 
QgsGeometry QgsGeometry::taperedBuffer( double startWidth, double endWidth, int segments ) const
{
  QgsInternalGeometryEngine engine( *this );
 
  return engine.taperedBuffer( startWidth, endWidth, segments );
}
 
QgsGeometry QgsGeometry::variableWidthBufferByM( int segments ) const
{
  QgsInternalGeometryEngine engine( *this );
 
  return engine.variableWidthBufferByM( segments );
}
 
QgsGeometry QgsGeometry::extendLine( double startDistance, double endDistance, double startDeflection, double endDeflection ) const
{
  if ( !d->geometry || type() != Qgis::GeometryType::Line )
  {
    return QgsGeometry();
  }
 
  if ( QgsWkbTypes::isMultiType( d->geometry->wkbType() ) )
  {
    const QVector<QgsGeometry> parts = asGeometryCollection();
    QVector<QgsGeometry> results;
    results.reserve( parts.count() );
    for ( const QgsGeometry &part : parts )
    {
      QgsGeometry result = part.extendLine( startDistance, endDistance, startDeflection, endDeflection );
      if ( !result.isNull() )
        results << result;
    }
    if ( results.isEmpty() )
      return QgsGeometry();
 
    QgsGeometry first = results.takeAt( 0 );
    for ( const QgsGeometry &result : std::as_const( results ) )
    {
      first.addPart( result );
    }
    return first;
  }
  else
  {
    QgsLineString *line = qgsgeometry_cast< QgsLineString * >( d->geometry.get() );
    if ( !line )
      return QgsGeometry();
 
    std::unique_ptr< QgsLineString > newLine( line->clone() );
    newLine->extend( startDistance, endDistance, startDeflection, endDeflection );
    return QgsGeometry( std::move( newLine ) );
  }
}
 
QgsGeometry QgsGeometry::simplify( double tolerance, QgsFeedback *feedback ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > simplifiedGeom( geos.simplify( tolerance, &mLastError, feedback ) );
  if ( !simplifiedGeom )
  {
    QgsGeometry result;
    result.mLastError = mLastError;
    return result;
  }
  return QgsGeometry( std::move( simplifiedGeom ) );
}
 
QgsGeometry QgsGeometry::densifyByCount( int extraNodesPerSegment ) const
{
  QgsInternalGeometryEngine engine( *this );
 
  return engine.densifyByCount( extraNodesPerSegment );
}
 
QgsGeometry QgsGeometry::densifyByDistance( double distance ) const
{
  QgsInternalGeometryEngine engine( *this );
 
  return engine.densifyByDistance( distance );
}
 
QgsGeometry QgsGeometry::convertToCurves( double distanceTolerance, double angleTolerance ) const
{
  QgsInternalGeometryEngine engine( *this );
 
  return engine.convertToCurves( distanceTolerance, angleTolerance );
}
 
QgsGeometry QgsGeometry::centroid() const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  // avoid calling geos for trivial point centroids
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::Point )
  {
    QgsGeometry c = *this;
    c.get()->dropZValue();
    c.get()->dropMValue();
    return c;
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  QgsGeometry result( geos.centroid( &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::pointOnSurface() const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  QgsGeometry result( geos.pointOnSurface( &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::poleOfInaccessibility( double precision, double *distanceToBoundary ) const
{
  QgsInternalGeometryEngine engine( *this );
 
  return engine.poleOfInaccessibility( precision, distanceToBoundary );
}
 
QgsGeometry QgsGeometry::largestEmptyCircle( double tolerance, const QgsGeometry &boundary ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  QgsGeometry result( geos.largestEmptyCircle( tolerance, boundary.constGet(), &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::minimumWidth() const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  QgsGeometry result( geos.minimumWidth( &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
double QgsGeometry::minimumClearance() const
{
  if ( !d->geometry )
  {
    return std::numeric_limits< double >::quiet_NaN();
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  return geos.minimumClearance( &mLastError );
}
 
QgsGeometry QgsGeometry::minimumClearanceLine() const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  QgsGeometry result( geos.minimumClearanceLine( &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::convexHull() const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > cHull( geos.convexHull( &mLastError ) );
  if ( !cHull )
  {
    QgsGeometry geom;
    geom.mLastError = mLastError;
    return geom;
  }
  return QgsGeometry( std::move( cHull ) );
}
 
QgsGeometry QgsGeometry::concaveHull( double targetPercent, bool allowHoles, QgsFeedback *feedback ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > concaveHull( geos.concaveHull( targetPercent, allowHoles, &mLastError, feedback ) );
  if ( !concaveHull )
  {
    QgsGeometry geom;
    geom.mLastError = mLastError;
    return geom;
  }
  return QgsGeometry( std::move( concaveHull ) );
}
 
QgsGeometry QgsGeometry::concaveHullOfPolygons( double lengthRatio, bool allowHoles, bool isTight, QgsFeedback *feedback ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  if ( type() != Qgis::GeometryType::Polygon )
  {
    QgsGeometry geom;
    geom.mLastError = u"Only Polygon or MultiPolygon geometries are supported"_s;
    return geom;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > concaveHull( geos.concaveHullOfPolygons( lengthRatio, allowHoles, isTight, &mLastError, feedback ) );
  if ( !concaveHull )
  {
    QgsGeometry geom;
    geom.mLastError = mLastError;
    return geom;
  }
  return QgsGeometry( std::move( concaveHull ) );
}
 
QgsGeometry QgsGeometry::voronoiDiagram( const QgsGeometry &extent, double tolerance, bool edgesOnly ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result = QgsGeometry( geos.voronoiDiagram( extent.constGet(), tolerance, edgesOnly, &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::delaunayTriangulation( double tolerance, bool edgesOnly ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result = QgsGeometry( geos.delaunayTriangulation( tolerance, edgesOnly ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::constrainedDelaunayTriangulation() const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result( geos.constrainedDelaunayTriangulation() );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::unionCoverage() const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) != Qgis::WkbType::GeometryCollection
       && QgsWkbTypes::flatType( d->geometry->wkbType() ) != Qgis::WkbType::MultiPolygon
       && QgsWkbTypes::flatType( d->geometry->wkbType() ) != Qgis::WkbType::Polygon )
    return QgsGeometry();
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  const QgsGeometry result = QgsGeometry( geos.unionCoverage( &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
Qgis::CoverageValidityResult QgsGeometry::validateCoverage( double gapWidth, QgsGeometry *invalidEdges ) const
{
  if ( !d->geometry )
  {
    return Qgis::CoverageValidityResult::Error;
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > invalidEdgesGeom;
 
  const Qgis::CoverageValidityResult result = geos.validateCoverage( gapWidth, invalidEdges ? &invalidEdgesGeom : nullptr, &mLastError );
 
  if ( invalidEdges && invalidEdgesGeom )
    *invalidEdges = QgsGeometry( std::move( invalidEdgesGeom ) );
 
  return result;
}
 
QgsGeometry QgsGeometry::simplifyCoverageVW( double tolerance, bool preserveBoundary ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result( geos.simplifyCoverageVW( tolerance, preserveBoundary, &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::cleanCoverage( const QgsCoverageCleanParameters &parameters, QgsFeedback *feedback ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) != Qgis::WkbType::GeometryCollection
       && QgsWkbTypes::flatType( d->geometry->wkbType() ) != Qgis::WkbType::MultiPolygon
       && QgsWkbTypes::flatType( d->geometry->wkbType() ) != Qgis::WkbType::Polygon )
    return QgsGeometry();
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  const QgsGeometry result( geos.cleanCoverage( parameters, &mLastError, feedback ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::node() const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result( geos.node( &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::sharedPaths( const QgsGeometry &other ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result( geos.sharedPaths( other.constGet(), &mLastError ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::subdivide( int maxNodes, const QgsGeometryParameters &parameters, QgsFeedback *feedback ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  const QgsAbstractGeometry *geom = d->geometry.get();
  std::unique_ptr< QgsAbstractGeometry > segmentizedCopy;
  if ( QgsWkbTypes::isCurvedType( d->geometry->wkbType() ) )
  {
    segmentizedCopy.reset( d->geometry->segmentize() );
    geom = segmentizedCopy.get();
  }
 
  QgsGeos geos( geom );
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > result( geos.subdivide( maxNodes, &mLastError, parameters, feedback ) );
  if ( !result )
  {
    QgsGeometry geom;
    geom.mLastError = mLastError;
    return geom;
  }
  return QgsGeometry( std::move( result ) );
}
 
QgsGeometry QgsGeometry::interpolate( double distance ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  QgsGeometry line = *this;
  if ( type() == Qgis::GeometryType::Point )
    return QgsGeometry();
  else if ( type() == Qgis::GeometryType::Polygon )
  {
    line = QgsGeometry( d->geometry->boundary() );
  }
 
  const QgsCurve *curve = nullptr;
  if ( const QgsGeometryCollection *collection = qgsgeometry_cast< const QgsGeometryCollection * >( line.constGet() ) )
  {
    // if multi part, iterate through parts to find target part
    for ( int part = 0; part < collection->numGeometries(); ++part )
    {
      const QgsCurve *candidate = qgsgeometry_cast< const QgsCurve * >( collection->geometryN( part ) );
      if ( !candidate )
        continue;
      const double candidateLength = candidate->length();
      if ( candidateLength >= distance )
      {
        curve = candidate;
        break;
      }
 
      distance -= candidateLength;
    }
  }
  else
  {
    curve = qgsgeometry_cast< const QgsCurve * >( line.constGet() );
  }
  if ( !curve )
    return QgsGeometry();
 
  std::unique_ptr< QgsPoint > result( curve->interpolatePoint( distance ) );
  if ( !result )
  {
    return QgsGeometry();
  }
  return QgsGeometry( std::move( result ) );
}
 
double QgsGeometry::lineLocatePoint( const QgsGeometry &point ) const
{
  if ( type() != Qgis::GeometryType::Line )
    return -1;
 
  if ( QgsWkbTypes::flatType( point.wkbType() ) != Qgis::WkbType::Point )
    return -1;
 
  QgsGeometry segmentized = *this;
  if ( QgsWkbTypes::isCurvedType( wkbType() ) )
  {
    segmentized = QgsGeometry( static_cast< QgsCurve * >( d->geometry.get() )->segmentize() );
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.lineLocatePoint( *( static_cast< QgsPoint * >( point.d->geometry.get() ) ), &mLastError );
}
 
double QgsGeometry::interpolateAngle( double distance ) const
{
  if ( !d->geometry || d->geometry->isEmpty() )
    return 0.0;
 
  const QgsAbstractGeometry *geom = d->geometry->simplifiedTypeRef();
  if ( QgsWkbTypes::geometryType( geom->wkbType() ) == Qgis::GeometryType::Point )
    return 0.0;
 
  // always operate on segmentized geometries
  QgsGeometry segmentized = *this;
  if ( QgsWkbTypes::isCurvedType( geom->wkbType() ) )
  {
    segmentized = QgsGeometry( static_cast< const QgsCurve * >( geom )->segmentize() );
  }
 
  QgsVertexId previous;
  QgsVertexId next;
  if ( !QgsGeometryUtils::verticesAtDistance( *segmentized.constGet(), distance, previous, next ) )
    return 0.0;
 
  if ( previous == next )
  {
    // distance coincided exactly with a vertex
    QgsVertexId v2 = previous;
    QgsVertexId v1;
    QgsVertexId v3;
    segmentized.constGet()->adjacentVertices( v2, v1, v3 );
    if ( v1.isValid() && v3.isValid() )
    {
      QgsPoint p1 = segmentized.constGet()->vertexAt( v1 );
      QgsPoint p2 = segmentized.constGet()->vertexAt( v2 );
      QgsPoint p3 = segmentized.constGet()->vertexAt( v3 );
      double angle1 = QgsGeometryUtilsBase::lineAngle( p1.x(), p1.y(), p2.x(), p2.y() );
      double angle2 = QgsGeometryUtilsBase::lineAngle( p2.x(), p2.y(), p3.x(), p3.y() );
      return QgsGeometryUtilsBase::averageAngle( angle1, angle2 );
    }
    else if ( v3.isValid() )
    {
      QgsPoint p1 = segmentized.constGet()->vertexAt( v2 );
      QgsPoint p2 = segmentized.constGet()->vertexAt( v3 );
      return QgsGeometryUtilsBase::lineAngle( p1.x(), p1.y(), p2.x(), p2.y() );
    }
    else
    {
      QgsPoint p1 = segmentized.constGet()->vertexAt( v1 );
      QgsPoint p2 = segmentized.constGet()->vertexAt( v2 );
      return QgsGeometryUtilsBase::lineAngle( p1.x(), p1.y(), p2.x(), p2.y() );
    }
  }
  else
  {
    QgsPoint p1 = segmentized.constGet()->vertexAt( previous );
    QgsPoint p2 = segmentized.constGet()->vertexAt( next );
    return QgsGeometryUtilsBase::lineAngle( p1.x(), p1.y(), p2.x(), p2.y() );
  }
}
 
QgsGeometry QgsGeometry::intersection( const QgsGeometry &geometry, const QgsGeometryParameters &parameters, QgsFeedback *feedback ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > resultGeom( geos.intersection( geometry.d->geometry.get(), &mLastError, parameters, feedback ) );
 
  if ( !resultGeom )
  {
    QgsGeometry geom;
    geom.mLastError = mLastError;
    return geom;
  }
 
  return QgsGeometry( std::move( resultGeom ) );
}
 
QgsGeometry QgsGeometry::combine( const QgsGeometry &geometry, const QgsGeometryParameters &parameters, QgsFeedback *feedback ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > resultGeom( geos.combine( geometry.d->geometry.get(), &mLastError, parameters, feedback ) );
  if ( !resultGeom )
  {
    QgsGeometry geom;
    geom.mLastError = mLastError;
    return geom;
  }
  return QgsGeometry( std::move( resultGeom ) );
}
 
QgsGeometry QgsGeometry::mergeLines( const QgsGeometryParameters &parameters ) const
{
  if ( !d->geometry )
  {
    return QgsGeometry();
  }
 
  if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::LineString )
  {
    // special case - a single linestring was passed
    return QgsGeometry( *this );
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  QgsGeometry result( geos.mergeLines( &mLastError, parameters ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::difference( const QgsGeometry &geometry, const QgsGeometryParameters &parameters, QgsFeedback *feedback ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > resultGeom( geos.difference( geometry.d->geometry.get(), &mLastError, parameters, feedback ) );
  if ( !resultGeom )
  {
    QgsGeometry geom;
    geom.mLastError = mLastError;
    return geom;
  }
  return QgsGeometry( std::move( resultGeom ) );
}
 
QgsGeometry QgsGeometry::symDifference( const QgsGeometry &geometry, const QgsGeometryParameters &parameters, QgsFeedback *feedback ) const
{
  if ( !d->geometry || geometry.isNull() )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
 
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > resultGeom( geos.symDifference( geometry.d->geometry.get(), &mLastError, parameters, feedback ) );
  if ( !resultGeom )
  {
    QgsGeometry geom;
    geom.mLastError = mLastError;
    return geom;
  }
  return QgsGeometry( std::move( resultGeom ) );
}
 
QgsGeometry QgsGeometry::extrude( double x, double y )
{
  QgsInternalGeometryEngine engine( *this );
 
  return engine.extrude( x, y );
}

 
QVector<QgsPointXY> QgsGeometry::randomPointsInPolygon( int count, const std::function< bool( const QgsPointXY & ) > &acceptPoint, unsigned long seed, QgsFeedback *feedback, int maxTriesPerPoint ) const
{
  if ( type() != Qgis::GeometryType::Polygon )
    return QVector< QgsPointXY >();
 
  QgsInternalGeometryEngine engine( *this );
  const QVector<QgsPointXY> res = engine.randomPointsInPolygon( count, acceptPoint, seed, feedback, maxTriesPerPoint );
  mLastError = engine.lastError();
  return res;
}
 
QVector<QgsPointXY> QgsGeometry::randomPointsInPolygon( int count, unsigned long seed, QgsFeedback *feedback ) const
{
  if ( type() != Qgis::GeometryType::Polygon )
    return QVector< QgsPointXY >();
 
  QgsInternalGeometryEngine engine( *this );
  const QVector<QgsPointXY> res = engine.randomPointsInPolygon( count, []( const QgsPointXY & ) { return true; }, seed, feedback, 0 );
  mLastError = engine.lastError();
  return res;
}
 
int QgsGeometry::wkbSize( QgsAbstractGeometry::WkbFlags flags ) const
{
  return d->geometry ? d->geometry->wkbSize( flags ) : 0;
}
 
QByteArray QgsGeometry::asWkb( QgsAbstractGeometry::WkbFlags flags ) const
{
  return d->geometry ? d->geometry->asWkb( flags ) : QByteArray();
}
 
QVector<QgsGeometry> QgsGeometry::asGeometryCollection() const
{
  QVector<QgsGeometry> geometryList;
  if ( !d->geometry )
  {
    return geometryList;
  }
 
  QgsGeometryCollection *gc = qgsgeometry_cast<QgsGeometryCollection *>( d->geometry.get() );
  if ( gc )
  {
    int numGeom = gc->numGeometries();
    geometryList.reserve( numGeom );
    for ( int i = 0; i < numGeom; ++i )
    {
      geometryList.append( QgsGeometry( gc->geometryN( i )->clone() ) );
    }
  }
  else //a singlepart geometry
  {
    geometryList.append( *this );
  }
 
  return geometryList;
}
 
QPointF QgsGeometry::asQPointF() const
{
  QgsPointXY point = asPoint();
  return point.toQPointF();
}
 
QPolygonF QgsGeometry::asQPolygonF() const
{
  const QgsAbstractGeometry *part = constGet();
 
  // if a geometry collection, get first part only
  if ( const QgsGeometryCollection *collection = qgsgeometry_cast< const QgsGeometryCollection *>( part ) )
  {
    if ( collection->numGeometries() > 0 )
      part = collection->geometryN( 0 );
    else
      return QPolygonF();
  }
 
  if ( const QgsCurve *curve = qgsgeometry_cast< const QgsCurve * >( part ) )
    return curve->asQPolygonF();
  else if ( const QgsCurvePolygon *polygon = qgsgeometry_cast< const QgsCurvePolygon * >( part ) )
    return polygon->exteriorRing() ? polygon->exteriorRing()->asQPolygonF() : QPolygonF();
  return QPolygonF();
}
 
bool QgsGeometry::deleteRing( int ringNum, int partNum )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  detach();
  bool ok = QgsGeometryEditUtils::deleteRing( d->geometry.get(), ringNum, partNum );
  return ok;
}
 
bool QgsGeometry::deletePart( int partNum )
{
  if ( !d->geometry )
  {
    return false;
  }
 
  if ( !isMultipart() && partNum < 1 )
  {
    set( nullptr );
    return true;
  }
 
  detach();
  bool ok = QgsGeometryEditUtils::deletePart( d->geometry.get(), partNum );
  return ok;
}
 
Qgis::GeometryOperationResult QgsGeometry::avoidIntersectionsV2( const QList<QgsVectorLayer *> &avoidIntersectionsLayers, const QHash<QgsVectorLayer *, QSet<QgsFeatureId> > &ignoreFeatures )
{
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidInputGeometryType;
  }
 
  Qgis::WkbType geomTypeBeforeModification = wkbType();
 
  bool haveInvalidGeometry = false;
  bool geomModified = false;
 
  std::unique_ptr< QgsAbstractGeometry > diffGeom = QgsGeometryEditUtils::avoidIntersections( *( d->geometry ), avoidIntersectionsLayers, haveInvalidGeometry, ignoreFeatures );
  if ( diffGeom )
  {
    reset( std::move( diffGeom ) );
    geomModified = true;
  }
 
  if ( geomTypeBeforeModification != wkbType() )
    return Qgis::GeometryOperationResult::GeometryTypeHasChanged;
  if ( haveInvalidGeometry )
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  if ( !geomModified )
    return Qgis::GeometryOperationResult::NothingHappened;
 
  return Qgis::GeometryOperationResult::Success;
}
 
int QgsGeometry::avoidIntersections( const QList<QgsVectorLayer *> &avoidIntersectionsLayers, const QHash<QgsVectorLayer *, QSet<QgsFeatureId> > &ignoreFeatures )
{
  const Qgis::GeometryOperationResult result = avoidIntersectionsV2( avoidIntersectionsLayers, ignoreFeatures );
  switch ( result )
  {
    case Qgis::GeometryOperationResult::Success:
      return 0;
    case Qgis::GeometryOperationResult::InvalidInputGeometryType:
      return 1;
    case Qgis::GeometryOperationResult::GeometryTypeHasChanged:
      return 2;
    case Qgis::GeometryOperationResult::InvalidBaseGeometry:
      return 3;
    case Qgis::GeometryOperationResult::NothingHappened:
 
    // these should never happen
    case Qgis::GeometryOperationResult::SelectionIsEmpty:
    case Qgis::GeometryOperationResult::SelectionIsGreaterThanOne:
    case Qgis::GeometryOperationResult::GeometryEngineError:
    case Qgis::GeometryOperationResult::LayerNotEditable:
    case Qgis::GeometryOperationResult::AddPartSelectedGeometryNotFound:
    case Qgis::GeometryOperationResult::AddPartNotMultiGeometry:
    case Qgis::GeometryOperationResult::AddRingNotClosed:
    case Qgis::GeometryOperationResult::AddRingNotValid:
    case Qgis::GeometryOperationResult::AddRingCrossesExistingRings:
    case Qgis::GeometryOperationResult::AddRingNotInExistingFeature:
    case Qgis::GeometryOperationResult::SplitCannotSplitPoint:
      return 4;
  }
  return 4;
}
 
QgsGeometry QgsGeometry::makeValid( Qgis::MakeValidMethod method, bool keepCollapsed, QgsFeedback *feedback ) const
{
  if ( !d->geometry )
    return QgsGeometry();
 
  mLastError.clear();
  QgsGeos geos( d->geometry.get() );
  std::unique_ptr< QgsAbstractGeometry > g( geos.makeValid( method, keepCollapsed, &mLastError, feedback ) );
 
  QgsGeometry result = QgsGeometry( std::move( g ) );
  result.mLastError = mLastError;
  return result;
}
 
QgsGeometry QgsGeometry::forceRHR() const
{
  return forcePolygonClockwise();
}
 
Qgis::AngularDirection QgsGeometry::polygonOrientation() const
{
  if ( !d->geometry )
  {
    return Qgis::AngularDirection::NoOrientation;
  }
 
  if ( isMultipart() )
  {
    const QgsGeometryCollection *collection = qgsgeometry_cast< const QgsGeometryCollection * >( d->geometry.get() );
    const QgsAbstractGeometry *g = collection->geometryN( 0 );
    if ( const QgsCurvePolygon *cp = qgsgeometry_cast< const QgsCurvePolygon * >( g ) )
    {
      return cp->exteriorRing() ? cp->exteriorRing()->orientation() : Qgis::AngularDirection::NoOrientation;
    }
  }
  else
  {
    if ( const QgsCurvePolygon *cp = qgsgeometry_cast< const QgsCurvePolygon * >( d->geometry.get() ) )
    {
      return cp->exteriorRing() ? cp->exteriorRing()->orientation() : Qgis::AngularDirection::NoOrientation;
    }
  }
 
  return Qgis::AngularDirection::NoOrientation;
}
 
QgsGeometry QgsGeometry::forcePolygonClockwise() const
{
  if ( !d->geometry )
    return QgsGeometry();
 
  if ( isMultipart() )
  {
    const QgsGeometryCollection *collection = qgsgeometry_cast< const QgsGeometryCollection * >( d->geometry.get() );
    std::unique_ptr< QgsGeometryCollection > newCollection( collection->createEmptyWithSameType() );
    newCollection->reserve( collection->numGeometries() );
    for ( int i = 0; i < collection->numGeometries(); ++i )
    {
      const QgsAbstractGeometry *g = collection->geometryN( i );
      if ( const QgsCurvePolygon *cp = qgsgeometry_cast< const QgsCurvePolygon * >( g ) )
      {
        std::unique_ptr< QgsCurvePolygon > corrected( cp->clone() );
        corrected->forceClockwise();
        newCollection->addGeometry( corrected.release() );
      }
      else
      {
        newCollection->addGeometry( g->clone() );
      }
    }
    return QgsGeometry( std::move( newCollection ) );
  }
  else
  {
    if ( const QgsCurvePolygon *cp = qgsgeometry_cast< const QgsCurvePolygon * >( d->geometry.get() ) )
    {
      std::unique_ptr< QgsCurvePolygon > corrected( cp->clone() );
      corrected->forceClockwise();
      return QgsGeometry( std::move( corrected ) );
    }
    else
    {
      // not a curve polygon, so return unchanged
      return *this;
    }
  }
}
 
QgsGeometry QgsGeometry::forcePolygonCounterClockwise() const
{
  if ( !d->geometry )
    return QgsGeometry();
 
  if ( isMultipart() )
  {
    const QgsGeometryCollection *collection = qgsgeometry_cast< const QgsGeometryCollection * >( d->geometry.get() );
    std::unique_ptr< QgsGeometryCollection > newCollection( collection->createEmptyWithSameType() );
    newCollection->reserve( collection->numGeometries() );
    for ( int i = 0; i < collection->numGeometries(); ++i )
    {
      const QgsAbstractGeometry *g = collection->geometryN( i );
      if ( const QgsCurvePolygon *cp = qgsgeometry_cast< const QgsCurvePolygon * >( g ) )
      {
        std::unique_ptr< QgsCurvePolygon > corrected( cp->clone() );
        corrected->forceCounterClockwise();
        newCollection->addGeometry( corrected.release() );
      }
      else
      {
        newCollection->addGeometry( g->clone() );
      }
    }
    return QgsGeometry( std::move( newCollection ) );
  }
  else
  {
    if ( const QgsCurvePolygon *cp = qgsgeometry_cast< const QgsCurvePolygon * >( d->geometry.get() ) )
    {
      std::unique_ptr< QgsCurvePolygon > corrected( cp->clone() );
      corrected->forceCounterClockwise();
      return QgsGeometry( std::move( corrected ) );
    }
    else
    {
      // not a curve polygon, so return unchanged
      return *this;
    }
  }
}
 
 
void QgsGeometry::validateGeometry( QVector<QgsGeometry::Error> &errors, const Qgis::GeometryValidationEngine method, const Qgis::GeometryValidityFlags flags ) const
{
  errors.clear();
  if ( !d->geometry )
    return;
 
  // avoid expensive calcs for trivial point geometries
  if ( QgsWkbTypes::geometryType( d->geometry->wkbType() ) == Qgis::GeometryType::Point )
  {
    return;
  }
 
  switch ( method )
  {
    case Qgis::GeometryValidationEngine::QgisInternal:
      QgsGeometryValidator::validateGeometry( *this, errors, method );
      return;
 
    case Qgis::GeometryValidationEngine::Geos:
    {
      QgsGeos geos( d->geometry.get(), 0, Qgis::GeosCreationFlags() );
      QString error;
      QgsGeometry errorLoc;
      if ( !geos.isValid( &error, flags & Qgis::GeometryValidityFlag::AllowSelfTouchingHoles, &errorLoc ) )
      {
        if ( errorLoc.isNull() )
        {
          errors.append( QgsGeometry::Error( error ) );
        }
        else
        {
          const QgsPointXY point = errorLoc.asPoint();
          errors.append( QgsGeometry::Error( error, point ) );
        }
        return;
      }
      break;
    }
    case Qgis::GeometryValidationEngine::Sfcgal:
    {
#ifdef WITH_SFCGAL
      QString errorMsg;
      QgsGeometry errorLoc;
      const QgsSfcgalGeometry sfcgalGeom( d->geometry.get() );
      if ( !QgsSfcgalEngine::isValid( sfcgalGeom.sfcgalGeometry().get(), nullptr, &errorMsg, &errorLoc ) )
      {
        if ( errorLoc.isNull() )
        {
          errors.append( QgsGeometry::Error( errorMsg ) );
        }
        else
        {
          const QgsPointXY point = errorLoc.asPoint();
          errors.append( QgsGeometry::Error( errorMsg, point ) );
        }
        return;
      }
#else
      throw QgsNotSupportedException( u"This operation requires a QGIS installation with SFCGAL support enabled. Please use a version of QGIS that includes SFCGAL."_s );
#endif
    }
  }
}
 
void QgsGeometry::normalize()
{
  if ( !d->geometry )
  {
    return;
  }
 
  detach();
  d->geometry->normalize();
}
 
bool QgsGeometry::isGeosValid( Qgis::GeometryValidityFlags flags ) const
{
  if ( !d->geometry )
  {
    return false;
  }
 
  return d->geometry->isValid( mLastError, flags );
}
 
bool QgsGeometry::isSimple() const
{
  if ( !d->geometry )
    return false;
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  return geos.isSimple( &mLastError );
}
 
bool QgsGeometry::isAxisParallelRectangle( double maximumDeviation, bool simpleRectanglesOnly ) const
{
  if ( !d->geometry )
    return false;
 
  QgsInternalGeometryEngine engine( *this );
  return engine.isAxisParallelRectangle( maximumDeviation, simpleRectanglesOnly );
}
 
bool QgsGeometry::isGeosEqual( const QgsGeometry &g ) const
{
  return isTopologicallyEqual( g, Qgis::GeometryBackend::GEOS );
}
 
bool QgsGeometry::isExactlyEqual( const QgsGeometry &g, Qgis::GeometryBackend backend ) const
{
  // === WARNING ===
  // if tolerance/epsilon value is changed in `geos.isFuzzyEqual` or in implementation of `QgsAbstractGeometry::operator==`, documentation must be updaded accordingly and also changed in expression helper files (resources/function_help/json)
 
  if ( !d->geometry || g.isNull() )
  {
    return false;
  }
 
  // fast check - are they shared copies of the same underlying geometry?
  if ( d == g.d )
    return true;
 
  // fast check - distinct geometry types?
  if ( type() != g.type() )
    return false;
 
  mLastError.clear();
  switch ( backend )
  {
    case Qgis::GeometryBackend::GEOS:
    {
      // avoid calling geos for trivial point case
      if ( QgsWkbTypes::flatType( d->geometry->wkbType() ) == Qgis::WkbType::Point && QgsWkbTypes::flatType( g.d->geometry->wkbType() ) == Qgis::WkbType::Point )
        return *d->geometry == *g.d->geometry;
 
      //  another nice fast check upfront -- if the bounding boxes aren't equal, the geometries themselves can't be equal!
      if ( d->geometry->boundingBox() != g.d->geometry->boundingBox() )
        return false;
 
      QgsGeos geos( d->geometry.get() );
      // fuzzy check call, with near zero epsilon, will behave as an exact comparison
      return geos.isFuzzyEqual( g.d->geometry.get(), 1e-8, &mLastError );
    }
 
    case Qgis::GeometryBackend::QGIS:
    {
      //  another nice fast check upfront -- if the bounding boxes aren't equal, the geometries themselves can't be equal!
      if ( ( !d->geometry->is3D() && d->geometry->boundingBox() != g.d->geometry->boundingBox() ) || ( d->geometry->is3D() && d->geometry->boundingBox3D() != g.d->geometry->boundingBox3D() ) )
        return false;
 
      // slower check - actually test the geometries
      return *d->geometry == *g.d->geometry;
    }
  }
  BUILTIN_UNREACHABLE
}
 
bool QgsGeometry::isTopologicallyEqual( const QgsGeometry &g, Qgis::GeometryBackend backend ) const
{
  if ( !d->geometry || !g.d->geometry )
  {
    return false;
  }
 
  // fast check - are they shared copies of the same underlying geometry?
  if ( d == g.d )
    return true;
 
  // fast check - distinct geometry types?
  if ( type() != g.type() )
    return false;
 
  mLastError.clear();
  switch ( backend )
  {
    case Qgis::GeometryBackend::GEOS:
    {
      //  another nice fast check upfront -- if the bounding boxes aren't equal, the geometries themselves can't be equal!
      if ( d->geometry->boundingBox() != g.d->geometry->boundingBox() )
        return false;
 
      QgsGeos geos( d->geometry.get() );
      return geos.isEqual( g.d->geometry.get(), &mLastError );
    }
 
    case Qgis::GeometryBackend::QGIS:
      throw QgsNotSupportedException( u"Geometry backend '%1' is not supported by this function."_s.arg( qgsEnumValueToKey( backend ) ) );
  }
  BUILTIN_UNREACHABLE
}
 
bool QgsGeometry::isFuzzyEqual( const QgsGeometry &g, double epsilon, Qgis::GeometryBackend backend ) const
{
  if ( !d->geometry || g.isNull() )
  {
    return false;
  }
 
  // fast check - are they shared copies of the same underlying geometry?
  if ( d == g.d )
    return true;
 
  // fast check - distinct geometry types?
  if ( type() != g.type() )
    return false;
 
  mLastError.clear();
  switch ( backend )
  {
    case Qgis::GeometryBackend::GEOS:
    {
      QgsGeos geos( d->geometry.get() );
      return geos.isFuzzyEqual( g.d->geometry.get(), epsilon, &mLastError );
    }
 
    case Qgis::GeometryBackend::QGIS:
    {
      // slower check - actually test the geometries
      return d->geometry->fuzzyEqual( *g.d->geometry, epsilon );
    }
  }
  BUILTIN_UNREACHABLE
}
 
QgsGeometry QgsGeometry::unaryUnion( const QVector<QgsGeometry> &geometries, const QgsGeometryParameters &parameters, QgsFeedback *feedback )
{
  QgsGeos geos( nullptr );
 
  QString error;
  std::unique_ptr< QgsAbstractGeometry > geom( geos.combine( geometries, &error, parameters, feedback ) );
  QgsGeometry result( std::move( geom ) );
  result.mLastError = error;
  return result;
}
 
QgsGeometry QgsGeometry::polygonize( const QVector<QgsGeometry> &geometryList )
{
  QVector<const QgsAbstractGeometry *> geomV2List;
  for ( const QgsGeometry &g : geometryList )
  {
    if ( !( g.isNull() ) )
    {
      geomV2List.append( g.constGet() );
    }
  }
 
  QString error;
  QgsGeometry result = QgsGeos::polygonize( geomV2List, &error );
  result.mLastError = error;
  return result;
}
 
void QgsGeometry::convertToStraightSegment( double tolerance, QgsAbstractGeometry::SegmentationToleranceType toleranceType )
{
  if ( !d->geometry || !requiresConversionToStraightSegments() )
  {
    return;
  }
 
  std::unique_ptr< QgsAbstractGeometry > straightGeom( d->geometry->segmentize( tolerance, toleranceType ) );
  reset( std::move( straightGeom ) );
}
 
bool QgsGeometry::requiresConversionToStraightSegments() const
{
  if ( !d->geometry )
  {
    return false;
  }
 
  return d->geometry->hasCurvedSegments();
}
 
Qgis::GeometryOperationResult QgsGeometry::transform( const QgsCoordinateTransform &ct, const Qgis::TransformDirection direction, const bool transformZ )
{
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  }
 
  detach();
  d->geometry->transform( ct, direction, transformZ );
  return Qgis::GeometryOperationResult::Success;
}
 
Qgis::GeometryOperationResult QgsGeometry::transform( const QTransform &ct, double zTranslate, double zScale, double mTranslate, double mScale )
{
  if ( !d->geometry )
  {
    return Qgis::GeometryOperationResult::InvalidBaseGeometry;
  }
 
  detach();
  d->geometry->transform( ct, zTranslate, zScale, mTranslate, mScale );
  return Qgis::GeometryOperationResult::Success;
}
 
void QgsGeometry::mapToPixel( const QgsMapToPixel &mtp )
{
  if ( d->geometry )
  {
    detach();
    d->geometry->transform( mtp.transform() );
  }
}
 
QgsGeometry QgsGeometry::clipped( const QgsRectangle &rectangle, QgsFeedback *feedback )
{
  if ( !d->geometry || rectangle.isNull() || rectangle.isEmpty() )
  {
    return QgsGeometry();
  }
 
  QgsGeos geos( d->geometry.get() );
  mLastError.clear();
  std::unique_ptr< QgsAbstractGeometry > resultGeom = geos.clip( rectangle, &mLastError, feedback );
  if ( !resultGeom )
  {
    QgsGeometry result;
    result.mLastError = mLastError;
    return result;
  }
  return QgsGeometry( std::move( resultGeom ) );
}
 
void QgsGeometry::draw( QPainter &p ) const
{
  if ( d->geometry )
  {
    d->geometry->draw( p );
  }
}
 
static bool vertexIndexInfo( const QgsAbstractGeometry *g, int vertexIndex, int &partIndex, int &ringIndex, int &vertex )
{
  if ( vertexIndex < 0 )
    return false; // clearly something wrong
 
  if ( const QgsGeometryCollection *geomCollection = qgsgeometry_cast<const QgsGeometryCollection *>( g ) )
  {
    partIndex = 0;
    for ( int i = 0; i < geomCollection->numGeometries(); ++i )
    {
      const QgsAbstractGeometry *part = geomCollection->geometryN( i );
 
      // count total number of vertices in the part
      int numPoints = 0;
      for ( int k = 0; k < part->ringCount(); ++k )
        numPoints += part->vertexCount( 0, k );
 
      if ( vertexIndex < numPoints )
      {
        int nothing;
        return vertexIndexInfo( part, vertexIndex, nothing, ringIndex, vertex ); // set ring_index + index
      }
      vertexIndex -= numPoints;
      partIndex++;
    }
  }
  else if ( const QgsPolyhedralSurface *polySurface = qgsgeometry_cast<const QgsPolyhedralSurface *>( g ) )
  {
    // PolyhedralSurface: patches are the parts
    partIndex = 0;
    for ( int i = 0; i < polySurface->numPatches(); ++i )
    {
      const QgsPolygon *patch = polySurface->patchN( i );
      // count total number of vertices in the patch
      int numPoints = 0;
      for ( int k = 0; k < patch->ringCount(); ++k )
        numPoints += patch->vertexCount( 0, k );
 
      if ( vertexIndex < numPoints )
      {
        int nothing;
        return vertexIndexInfo( patch, vertexIndex, nothing, ringIndex, vertex );
      }
      vertexIndex -= numPoints;
      partIndex++;
    }
  }
  else if ( const QgsCurvePolygon *curvePolygon = qgsgeometry_cast<const QgsCurvePolygon *>( g ) )
  {
    const QgsCurve *ring = curvePolygon->exteriorRing();
    if ( vertexIndex < ring->numPoints() )
    {
      partIndex = 0;
      ringIndex = 0;
      vertex = vertexIndex;
      return true;
    }
    vertexIndex -= ring->numPoints();
    ringIndex = 1;
    for ( int i = 0; i < curvePolygon->numInteriorRings(); ++i )
    {
      const QgsCurve *ring = curvePolygon->interiorRing( i );
      if ( vertexIndex < ring->numPoints() )
      {
        partIndex = 0;
        vertex = vertexIndex;
        return true;
      }
      vertexIndex -= ring->numPoints();
      ringIndex += 1;
    }
  }
  else if ( const QgsCurve *curve = qgsgeometry_cast<const QgsCurve *>( g ) )
  {
    if ( vertexIndex < curve->numPoints() )
    {
      partIndex = 0;
      ringIndex = 0;
      vertex = vertexIndex;
      return true;
    }
  }
  else if ( qgsgeometry_cast<const QgsPoint *>( g ) )
  {
    if ( vertexIndex == 0 )
    {
      partIndex = 0;
      ringIndex = 0;
      vertex = 0;
      return true;
    }
  }
 
  return false;
}
 
bool QgsGeometry::vertexIdFromVertexNr( int nr, QgsVertexId &id ) const
{
  if ( !d->geometry )
  {
    return false;
  }
 
  id.type = Qgis::VertexType::Segment;
 
  bool res = vertexIndexInfo( d->geometry.get(), nr, id.part, id.ring, id.vertex );
  if ( !res )
    return false;
 
  // now let's find out if it is a straight or circular segment
  const QgsAbstractGeometry *g = d->geometry.get();
  if ( const QgsGeometryCollection *geomCollection = qgsgeometry_cast<const QgsGeometryCollection *>( g ) )
  {
    g = geomCollection->geometryN( id.part );
  }
  else if ( const QgsPolyhedralSurface *polySurface = qgsgeometry_cast<const QgsPolyhedralSurface *>( g ) )
  {
    g = polySurface->patchN( id.part );
  }
 
  if ( const QgsCurvePolygon *curvePolygon = qgsgeometry_cast<const QgsCurvePolygon *>( g ) )
  {
    g = id.ring == 0 ? curvePolygon->exteriorRing() : curvePolygon->interiorRing( id.ring - 1 );
  }
 
  if ( const QgsCurve *curve = qgsgeometry_cast<const QgsCurve *>( g ) )
  {
    QgsPoint p;
    res = curve->pointAt( id.vertex, p, id.type );
    if ( !res )
      return false;
  }
 
  return true;
}
 
int QgsGeometry::vertexNrFromVertexId( QgsVertexId id ) const
{
  if ( !d->geometry )
  {
    return -1;
  }
  return d->geometry->vertexNumberFromVertexId( id );
}
 
QString QgsGeometry::lastError() const
{
  return mLastError;
}
 
void QgsGeometry::filterVertices( const std::function<bool( const QgsPoint & )> &filter )
{
  if ( !d->geometry )
    return;
 
  detach();
 
  d->geometry->filterVertices( filter );
}
 
void QgsGeometry::transformVertices( const std::function<QgsPoint( const QgsPoint & )> &transform )
{
  if ( !d->geometry )
    return;
 
  detach();
 
  d->geometry->transformVertices( transform );
}
 
void QgsGeometry::convertPointList( const QVector<QgsPointXY> &input, QgsPointSequence &output )
{
  output.clear();
  for ( const QgsPointXY &p : input )
  {
    output.append( QgsPoint( p ) );
  }
}
 
void QgsGeometry::convertPointList( const QgsPointSequence &input, QVector<QgsPointXY> &output )
{
  output.clear();
  for ( const QgsPoint &p : input )
  {
    output.append( QgsPointXY( p.x(), p.y() ) );
  }
}
 
void QgsGeometry::convertPolygon( const QgsPolygon &input, QgsPolygonXY &output )
{
  output.clear();
 
  auto convertRing = []( const QgsCurve *ring ) -> QgsPolylineXY {
    QgsPolylineXY res;
    bool doSegmentation = ( QgsWkbTypes::flatType( ring->wkbType() ) == Qgis::WkbType::CompoundCurve || QgsWkbTypes::flatType( ring->wkbType() ) == Qgis::WkbType::CircularString );
    std::unique_ptr< QgsLineString > segmentizedLine;
    const QgsLineString *line = nullptr;
    if ( doSegmentation )
    {
      segmentizedLine.reset( ring->curveToLine() );
      line = segmentizedLine.get();
    }
    else
    {
      line = qgsgeometry_cast<const QgsLineString *>( ring );
      if ( !line )
      {
        return res;
      }
    }
 
    int nVertices = line->numPoints();
    res.resize( nVertices );
    QgsPointXY *data = res.data();
    const double *xData = line->xData();
    const double *yData = line->yData();
    for ( int i = 0; i < nVertices; ++i )
    {
      data->setX( *xData++ );
      data->setY( *yData++ );
      data++;
    }
    return res;
  };
 
  if ( const QgsCurve *exterior = input.exteriorRing() )
  {
    output.push_back( convertRing( exterior ) );
  }
 
  const int interiorRingCount = input.numInteriorRings();
  output.reserve( output.size() + interiorRingCount );
  for ( int n = 0; n < interiorRingCount; ++n )
  {
    output.push_back( convertRing( input.interiorRing( n ) ) );
  }
}
 
QgsGeometry QgsGeometry::fromQPointF( QPointF point )
{
  return QgsGeometry( std::make_unique< QgsPoint >( point.x(), point.y() ) );
}
 
QgsGeometry QgsGeometry::fromQPolygonF( const QPolygonF &polygon )
{
  std::unique_ptr< QgsLineString > ring( QgsLineString::fromQPolygonF( polygon ) );
 
  if ( polygon.isClosed() )
  {
    auto poly = std::make_unique< QgsPolygon >();
    poly->setExteriorRing( ring.release() );
    return QgsGeometry( std::move( poly ) );
  }
  else
  {
    return QgsGeometry( std::move( ring ) );
  }
}
 
QgsPolygonXY QgsGeometry::createPolygonFromQPolygonF( const QPolygonF &polygon )
{
  Q_NOWARN_DEPRECATED_PUSH
  QgsPolygonXY result;
  result << createPolylineFromQPolygonF( polygon );
  return result;
  Q_NOWARN_DEPRECATED_POP
}
 
QgsPolylineXY QgsGeometry::createPolylineFromQPolygonF( const QPolygonF &polygon )
{
  QgsPolylineXY result;
  result.reserve( polygon.count() );
  for ( const QPointF &p : polygon )
  {
    result.append( QgsPointXY( p ) );
  }
  return result;
}
 
bool QgsGeometry::compare( const QgsPolylineXY &p1, const QgsPolylineXY &p2, double epsilon )
{
  if ( p1.count() != p2.count() )
    return false;
 
  for ( int i = 0; i < p1.count(); ++i )
  {
    if ( !p1.at( i ).compare( p2.at( i ), epsilon ) )
      return false;
  }
  return true;
}
 
bool QgsGeometry::compare( const QgsPolygonXY &p1, const QgsPolygonXY &p2, double epsilon )
{
  if ( p1.count() != p2.count() )
    return false;
 
  for ( int i = 0; i < p1.count(); ++i )
  {
    if ( !QgsGeometry::compare( p1.at( i ), p2.at( i ), epsilon ) )
      return false;
  }
  return true;
}
 
 
bool QgsGeometry::compare( const QgsMultiPolygonXY &p1, const QgsMultiPolygonXY &p2, double epsilon )
{
  if ( p1.count() != p2.count() )
    return false;
 
  for ( int i = 0; i < p1.count(); ++i )
  {
    if ( !QgsGeometry::compare( p1.at( i ), p2.at( i ), epsilon ) )
      return false;
  }
  return true;
}
 
QgsGeometry QgsGeometry::smooth( const unsigned int iterations, const double offset, double minimumDistance, double maxAngle ) const
{
  if ( !d->geometry || d->geometry->isEmpty() )
    return QgsGeometry();
 
  QgsGeometry geom = *this;
  if ( QgsWkbTypes::isCurvedType( wkbType() ) )
    geom = QgsGeometry( d->geometry->segmentize() );
 
  switch ( QgsWkbTypes::flatType( geom.wkbType() ) )
  {
    case Qgis::WkbType::Point:
    case Qgis::WkbType::MultiPoint:
      //can't smooth a point based geometry
      return geom;
 
    case Qgis::WkbType::LineString:
    {
      const QgsLineString *lineString = qgsgeometry_cast< const QgsLineString * >( geom.constGet() );
      return QgsGeometry( smoothLine( *lineString, iterations, offset, minimumDistance, maxAngle ) );
    }
 
    case Qgis::WkbType::MultiLineString:
    {
      const QgsMultiLineString *inputMultiLine = qgsgeometry_cast< const QgsMultiLineString * >( geom.constGet() );
 
      auto resultMultiline = std::make_unique< QgsMultiLineString>();
      resultMultiline->reserve( inputMultiLine->numGeometries() );
      for ( int i = 0; i < inputMultiLine->numGeometries(); ++i )
      {
        resultMultiline->addGeometry( smoothLine( *( inputMultiLine->lineStringN( i ) ), iterations, offset, minimumDistance, maxAngle ).release() );
      }
      return QgsGeometry( std::move( resultMultiline ) );
    }
 
    case Qgis::WkbType::Polygon:
    {
      const QgsPolygon *poly = qgsgeometry_cast< const QgsPolygon * >( geom.constGet() );
      return QgsGeometry( smoothPolygon( *poly, iterations, offset, minimumDistance, maxAngle ) );
    }
 
    case Qgis::WkbType::MultiPolygon:
    {
      const QgsMultiPolygon *inputMultiPoly = qgsgeometry_cast< const QgsMultiPolygon * >( geom.constGet() );
 
      auto resultMultiPoly = std::make_unique< QgsMultiPolygon >();
      resultMultiPoly->reserve( inputMultiPoly->numGeometries() );
      for ( int i = 0; i < inputMultiPoly->numGeometries(); ++i )
      {
        resultMultiPoly->addGeometry( smoothPolygon( *( inputMultiPoly->polygonN( i ) ), iterations, offset, minimumDistance, maxAngle ).release() );
      }
      return QgsGeometry( std::move( resultMultiPoly ) );
    }
 
    case Qgis::WkbType::Unknown:
    default:
      return QgsGeometry( *this );
  }
}
 
std::unique_ptr< QgsLineString > smoothCurve( const QgsLineString &line, const unsigned int iterations, const double offset, double squareDistThreshold, double maxAngleRads, bool isRing )
{
  auto result = std::make_unique< QgsLineString >( line );
  QgsPointSequence outputLine;
  for ( unsigned int iteration = 0; iteration < iterations; ++iteration )
  {
    outputLine.resize( 0 );
    outputLine.reserve( 2 * ( result->numPoints() - 1 ) );
    bool skipFirst = false;
    bool skipLast = false;
    if ( isRing )
    {
      QgsPoint p1 = result->pointN( result->numPoints() - 2 );
      QgsPoint p2 = result->pointN( 0 );
      QgsPoint p3 = result->pointN( 1 );
      double angle = QgsGeometryUtilsBase::angleBetweenThreePoints( p1.x(), p1.y(), p2.x(), p2.y(), p3.x(), p3.y() );
      angle = std::fabs( M_PI - angle );
      skipFirst = angle > maxAngleRads;
    }
    for ( int i = 0; i < result->numPoints() - 1; i++ )
    {
      QgsPoint p1 = result->pointN( i );
      QgsPoint p2 = result->pointN( i + 1 );
 
      double angle = M_PI;
      if ( i == 0 && isRing )
      {
        QgsPoint p3 = result->pointN( result->numPoints() - 2 );
        angle = QgsGeometryUtilsBase::angleBetweenThreePoints( p1.x(), p1.y(), p2.x(), p2.y(), p3.x(), p3.y() );
      }
      else if ( i < result->numPoints() - 2 )
      {
        QgsPoint p3 = result->pointN( i + 2 );
        angle = QgsGeometryUtilsBase::angleBetweenThreePoints( p1.x(), p1.y(), p2.x(), p2.y(), p3.x(), p3.y() );
      }
      else if ( i == result->numPoints() - 2 && isRing )
      {
        QgsPoint p3 = result->pointN( 1 );
        angle = QgsGeometryUtilsBase::angleBetweenThreePoints( p1.x(), p1.y(), p2.x(), p2.y(), p3.x(), p3.y() );
      }
 
      skipLast = angle < M_PI - maxAngleRads || angle > M_PI + maxAngleRads;
 
      // don't apply distance threshold to first or last segment
      if ( i == 0 || i >= result->numPoints() - 2 || QgsGeometryUtils::sqrDistance2D( p1, p2 ) > squareDistThreshold )
      {
        if ( !isRing )
        {
          if ( !skipFirst )
            outputLine << ( i == 0 ? result->pointN( i ) : QgsGeometryUtils::interpolatePointOnLine( p1, p2, offset ) );
          if ( !skipLast )
            outputLine << ( i == result->numPoints() - 2 ? result->pointN( i + 1 ) : QgsGeometryUtils::interpolatePointOnLine( p1, p2, 1.0 - offset ) );
          else
            outputLine << p2;
        }
        else
        {
          // ring
          if ( !skipFirst )
            outputLine << QgsGeometryUtils::interpolatePointOnLine( p1, p2, offset );
          else if ( i == 0 )
            outputLine << p1;
          if ( !skipLast )
            outputLine << QgsGeometryUtils::interpolatePointOnLine( p1, p2, 1.0 - offset );
          else
            outputLine << p2;
        }
      }
      skipFirst = skipLast;
    }
 
    if ( isRing && outputLine.at( 0 ) != outputLine.at( outputLine.count() - 1 ) )
      outputLine << outputLine.at( 0 );
 
    result->setPoints( outputLine );
  }
  return result;
}
 
std::unique_ptr<QgsLineString> QgsGeometry::smoothLine( const QgsLineString &line, const unsigned int iterations, const double offset, double minimumDistance, double maxAngle ) const
{
  double maxAngleRads = maxAngle * M_PI / 180.0;
  double squareDistThreshold = minimumDistance > 0 ? minimumDistance * minimumDistance : -1;
  return smoothCurve( line, iterations, offset, squareDistThreshold, maxAngleRads, false );
}
 
std::unique_ptr<QgsPolygon> QgsGeometry::smoothPolygon( const QgsPolygon &polygon, const unsigned int iterations, const double offset, double minimumDistance, double maxAngle ) const
{
  double maxAngleRads = maxAngle * M_PI / 180.0;
  double squareDistThreshold = minimumDistance > 0 ? minimumDistance * minimumDistance : -1;
  auto resultPoly = std::make_unique< QgsPolygon >();
 
  resultPoly->setExteriorRing( smoothCurve( *( static_cast< const QgsLineString *>( polygon.exteriorRing() ) ), iterations, offset, squareDistThreshold, maxAngleRads, true ).release() );
 
  for ( int i = 0; i < polygon.numInteriorRings(); ++i )
  {
    resultPoly->addInteriorRing( smoothCurve( *( static_cast< const QgsLineString *>( polygon.interiorRing( i ) ) ), iterations, offset, squareDistThreshold, maxAngleRads, true ).release() );
  }
  return resultPoly;
}
 
QgsGeometry QgsGeometry::convertToPoint( bool destMultipart ) const
{
  switch ( type() )
  {
    case Qgis::GeometryType::Point:
    {
      bool srcIsMultipart = isMultipart();
 
      if ( ( destMultipart && srcIsMultipart ) || ( !destMultipart && !srcIsMultipart ) )
      {
        // return a copy of the same geom
        return QgsGeometry( *this );
      }
      if ( destMultipart )
      {
        // layer is multipart => make a multipoint with a single point
        return fromMultiPointXY( QgsMultiPointXY() << asPoint() );
      }
      else
      {
        // destination is singlepart => make a single part if possible
        QgsMultiPointXY multiPoint = asMultiPoint();
        if ( multiPoint.count() == 1 )
        {
          return fromPointXY( multiPoint[0] );
        }
      }
      return QgsGeometry();
    }
 
    case Qgis::GeometryType::Line:
    {
      // only possible if destination is multipart
      if ( !destMultipart )
        return QgsGeometry();
 
      // input geometry is multipart
      if ( isMultipart() )
      {
        const QgsMultiPolylineXY inputMultiLine = asMultiPolyline();
        QgsMultiPointXY multiPoint;
        for ( const QgsPolylineXY &l : inputMultiLine )
          for ( const QgsPointXY &p : l )
            multiPoint << p;
        return fromMultiPointXY( multiPoint );
      }
      // input geometry is not multipart: copy directly the line into a multipoint
      else
      {
        QgsPolylineXY line = asPolyline();
        if ( !line.isEmpty() )
          return fromMultiPointXY( line );
      }
      return QgsGeometry();
    }
 
    case Qgis::GeometryType::Polygon:
    {
      // can only transform if destination is multipoint
      if ( !destMultipart )
        return QgsGeometry();
 
      // input geometry is multipart: make a multipoint from multipolygon
      if ( isMultipart() )
      {
        const QgsMultiPolygonXY multiPolygon = asMultiPolygon();
        QgsMultiPointXY multiPoint;
        for ( const QgsPolygonXY &poly : multiPolygon )
          for ( const QgsPolylineXY &line : poly )
            for ( const QgsPointXY &pt : line )
              multiPoint << pt;
        return fromMultiPointXY( multiPoint );
      }
      // input geometry is not multipart: make a multipoint from polygon
      else
      {
        const QgsPolygonXY polygon = asPolygon();
        QgsMultiPointXY multiPoint;
        for ( const QgsPolylineXY &line : polygon )
          for ( const QgsPointXY &pt : line )
            multiPoint << pt;
        return fromMultiPointXY( multiPoint );
      }
    }
 
    default:
      return QgsGeometry();
  }
}
 
QgsGeometry QgsGeometry::convertToLine( bool destMultipart ) const
{
  switch ( type() )
  {
    case Qgis::GeometryType::Point:
    {
      if ( !isMultipart() )
        return QgsGeometry();
 
      QgsMultiPointXY multiPoint = asMultiPoint();
      if ( multiPoint.count() < 2 )
        return QgsGeometry();
 
      if ( destMultipart )
        return fromMultiPolylineXY( QgsMultiPolylineXY() << multiPoint );
      else
        return fromPolylineXY( multiPoint );
    }
 
    case Qgis::GeometryType::Line:
    {
      bool srcIsMultipart = isMultipart();
 
      if ( ( destMultipart && srcIsMultipart ) || ( !destMultipart && !srcIsMultipart ) )
      {
        // return a copy of the same geom
        return QgsGeometry( *this );
      }
      if ( destMultipart )
      {
        // destination is multipart => makes a multipoint with a single line
        QgsPolylineXY line = asPolyline();
        if ( !line.isEmpty() )
          return fromMultiPolylineXY( QgsMultiPolylineXY() << line );
      }
      else
      {
        // destination is singlepart => make a single part if possible
        QgsMultiPolylineXY inputMultiLine = asMultiPolyline();
        if ( inputMultiLine.count() == 1 )
          return fromPolylineXY( inputMultiLine[0] );
      }
      return QgsGeometry();
    }
 
    case Qgis::GeometryType::Polygon:
    {
      // input geometry is multipolygon
      if ( isMultipart() )
      {
        const QgsMultiPolygonXY multiPolygon = asMultiPolygon();
        QgsMultiPolylineXY inputMultiLine;
        for ( const QgsPolygonXY &poly : multiPolygon )
          for ( const QgsPolylineXY &line : poly )
            inputMultiLine << line;
 
        if ( destMultipart )
        {
          // destination is multipart
          return fromMultiPolylineXY( inputMultiLine );
        }
        else if ( inputMultiLine.count() == 1 )
        {
          // destination is singlepart => make a single part if possible
          return fromPolylineXY( inputMultiLine[0] );
        }
      }
      // input geometry is single polygon
      else
      {
        QgsPolygonXY polygon = asPolygon();
        // if polygon has rings
        if ( polygon.count() > 1 )
        {
          // cannot fit a polygon with rings in a single line layer
          // TODO: would it be better to remove rings?
          if ( destMultipart )
          {
            const QgsPolygonXY polygon = asPolygon();
            QgsMultiPolylineXY inputMultiLine;
            inputMultiLine.reserve( polygon.count() );
            for ( const QgsPolylineXY &line : polygon )
              inputMultiLine << line;
            return fromMultiPolylineXY( inputMultiLine );
          }
        }
        // no rings
        else if ( polygon.count() == 1 )
        {
          if ( destMultipart )
          {
            return fromMultiPolylineXY( polygon );
          }
          else
          {
            return fromPolylineXY( polygon[0] );
          }
        }
      }
      return QgsGeometry();
    }
 
    default:
      return QgsGeometry();
  }
}
 
QgsGeometry QgsGeometry::convertToPolygon( bool destMultipart ) const
{
  switch ( type() )
  {
    case Qgis::GeometryType::Point:
    {
      if ( !isMultipart() )
        return QgsGeometry();
 
      QgsMultiPointXY multiPoint = asMultiPoint();
      if ( multiPoint.count() < 3 )
        return QgsGeometry();
 
      if ( multiPoint.last() != multiPoint.first() )
        multiPoint << multiPoint.first();
 
      QgsPolygonXY polygon = QgsPolygonXY() << multiPoint;
      if ( destMultipart )
        return fromMultiPolygonXY( QgsMultiPolygonXY() << polygon );
      else
        return fromPolygonXY( polygon );
    }
 
    case Qgis::GeometryType::Line:
    {
      // input geometry is multiline
      if ( isMultipart() )
      {
        QgsMultiPolylineXY inputMultiLine = asMultiPolyline();
        QgsMultiPolygonXY multiPolygon;
        for ( QgsMultiPolylineXY::iterator multiLineIt = inputMultiLine.begin(); multiLineIt != inputMultiLine.end(); ++multiLineIt )
        {
          // do not create polygon for a 1 segment line
          if ( ( *multiLineIt ).count() < 3 )
            return QgsGeometry();
          if ( ( *multiLineIt ).count() == 3 && ( *multiLineIt ).first() == ( *multiLineIt ).last() )
            return QgsGeometry();
 
          // add closing node
          if ( ( *multiLineIt ).first() != ( *multiLineIt ).last() )
            *multiLineIt << ( *multiLineIt ).first();
          multiPolygon << ( QgsPolygonXY() << *multiLineIt );
        }
        // check that polygons were inserted
        if ( !multiPolygon.isEmpty() )
        {
          if ( destMultipart )
          {
            return fromMultiPolygonXY( multiPolygon );
          }
          else if ( multiPolygon.count() == 1 )
          {
            // destination is singlepart => make a single part if possible
            return fromPolygonXY( multiPolygon[0] );
          }
        }
      }
      // input geometry is single line
      else
      {
        QgsPolylineXY line = asPolyline();
 
        // do not create polygon for a 1 segment line
        if ( line.count() < 3 )
          return QgsGeometry();
        if ( line.count() == 3 && line.first() == line.last() )
          return QgsGeometry();
 
        // add closing node
        if ( line.first() != line.last() )
          line << line.first();
 
        // destination is multipart
        if ( destMultipart )
        {
          return fromMultiPolygonXY( QgsMultiPolygonXY() << ( QgsPolygonXY() << line ) );
        }
        else
        {
          return fromPolygonXY( QgsPolygonXY() << line );
        }
      }
      return QgsGeometry();
    }
 
    case Qgis::GeometryType::Polygon:
    {
      bool srcIsMultipart = isMultipart();
 
      if ( ( destMultipart && srcIsMultipart ) || ( !destMultipart && !srcIsMultipart ) )
      {
        // return a copy of the same geom
        return QgsGeometry( *this );
      }
      if ( destMultipart )
      {
        // destination is multipart => makes a multipoint with a single polygon
        QgsPolygonXY polygon = asPolygon();
        if ( !polygon.isEmpty() )
          return fromMultiPolygonXY( QgsMultiPolygonXY() << polygon );
      }
      else
      {
        QgsMultiPolygonXY multiPolygon = asMultiPolygon();
        if ( multiPolygon.count() == 1 )
        {
          // destination is singlepart => make a single part if possible
          return fromPolygonXY( multiPolygon[0] );
        }
      }
      return QgsGeometry();
    }
 
    default:
      return QgsGeometry();
  }
}
 
QgsGeometryEngine *QgsGeometry::createGeometryEngine( const QgsAbstractGeometry *geometry, double precision, Qgis::GeosCreationFlags flags )
{
  return new QgsGeos( geometry, precision, flags );
}
 
QDataStream &operator<<( QDataStream &out, const QgsGeometry &geometry )
{
  out << geometry.asWkb();
  return out;
}
 
QDataStream &operator>>( QDataStream &in, QgsGeometry &geometry )
{
  QByteArray byteArray;
  in >> byteArray;
  if ( byteArray.isEmpty() )
  {
    geometry.set( nullptr );
    return in;
  }
 
  geometry.fromWkb( byteArray );
  return in;
}
 
 
QString QgsGeometry::Error::what() const
{
  return mMessage;
}
 
QgsPointXY QgsGeometry::Error::where() const
{
  return mLocation;
}
 
bool QgsGeometry::Error::hasWhere() const
{
  return mHasLocation;
}
 
QgsGeometry QgsGeometry::doChamferFillet( ChamferFilletOperationType op, int vertexIndex, double distance1, double distance2, int segments ) const
{
  QgsDebugMsgLevel( u"%1 starts: %2"_s.arg( qgsEnumValueToKey( op ) ).arg( asWkt( 2 ) ), 3 );
  if ( isNull() )
  {
    mLastError = u"Operation '%1' needs non-null geometry."_s.arg( qgsEnumValueToKey( op ) );
    return QgsGeometry();
  }
 
  QgsCurve *curve = nullptr;
 
  int modifiedPart = -1;
  int modifiedRing = -1;
  QgsVertexId vertexId;
  if ( !vertexIdFromVertexNr( vertexIndex, vertexId ) )
  {
    mLastError = u"Invalid vertex index"_s;
    return QgsGeometry();
  }
  int resolvedVertexIndex = vertexId.vertex;
  QgsMultiCurve *inputMultiCurve = nullptr;
  QgsMultiSurface *inputMultiSurface = nullptr;
  const Qgis::GeometryType geomType = QgsWkbTypes::geometryType( wkbType() );
 
  if ( geomType == Qgis::GeometryType::Line )
  {
    if ( isMultipart() )
    {
      modifiedPart = vertexId.part;
 
      inputMultiCurve = qgsgeometry_cast<QgsMultiCurve *>( d->geometry.get() );
      curve = dynamic_cast<QgsCurve *>( inputMultiCurve->curveN( modifiedPart ) );
    }
    else
    {
      curve = dynamic_cast<QgsCurve *>( d->geometry.get() );
    }
  }
  else if ( geomType == Qgis::GeometryType::Polygon )
  {
    QgsCurvePolygon *poly = nullptr;
    if ( isMultipart() )
    {
      modifiedPart = vertexId.part;
      // get part, get ring
      inputMultiSurface = qgsgeometry_cast<QgsMultiSurface *>( d->geometry.get() );
      poly = dynamic_cast<QgsCurvePolygon *>( inputMultiSurface->surfaceN( modifiedPart ) );
    }
    else
    {
      poly = qgsgeometry_cast<QgsCurvePolygon *>( d->geometry.get() );
    }
    if ( !poly )
    {
      mLastError = u"Could not get polygon geometry."_s;
      return QgsGeometry();
    }
 
    // if has rings
    modifiedRing = vertexId.ring;
    if ( modifiedRing == 0 )
      curve = qgsgeometry_cast<QgsCurve *>( poly->exteriorRing() );
    else
      curve = qgsgeometry_cast<QgsCurve *>( poly->interiorRing( modifiedRing - 1 ) );
  }
  else
    curve = nullptr;
 
  if ( !curve )
  {
    mLastError = u"Operation '%1' needs curve geometry."_s.arg( qgsEnumValueToKey( op ) );
    return QgsGeometry();
  }
 
  std::unique_ptr<QgsAbstractGeometry> result;
  try
  {
    if ( op == ChamferFilletOperationType::Chamfer )
      result = QgsGeometryUtils::chamferVertex( curve, resolvedVertexIndex, distance1, distance2 );
    else
      result = QgsGeometryUtils::filletVertex( curve, resolvedVertexIndex, distance1, segments );
  }
  catch ( QgsInvalidArgumentException &e )
  {
    mLastError = u"%1 Requested vertex: %2 was resolved as: [part: %3, ring: %4, vertex: %5]"_s //
                   .arg( e.what() )
                   .arg( vertexIndex )
                   .arg( modifiedPart )
                   .arg( modifiedRing )
                   .arg( resolvedVertexIndex );
    return QgsGeometry();
  }
 
  if ( !result )
  {
    mLastError = u"Operation '%1' generates a null geometry."_s.arg( qgsEnumValueToKey( op ) );
    return QgsGeometry();
  }
 
  if ( result->isEmpty() )
    return QgsGeometry( std::move( result ) );
 
  // insert \a result geometry (obtain by the chamfer/fillet operation) back into original \a inputPoly polygon
  auto updatePolygon = []( const QgsCurvePolygon *inputPoly, QgsAbstractGeometry *result, int modifiedRing ) -> std::unique_ptr<QgsCurvePolygon> {
    auto newPoly = std::make_unique<QgsCurvePolygon>();
    if ( qgsgeometry_cast<const QgsPolygon *>( inputPoly ) )
      newPoly = std::make_unique<QgsPolygon>();
 
    for ( int ringIndex = 0; ringIndex < inputPoly->numInteriorRings() + 1; ++ringIndex )
    {
      if ( ringIndex == modifiedRing )
      {
        for ( QgsAbstractGeometry::part_iterator resPartIte = result->parts_begin(); resPartIte != result->parts_end(); ++resPartIte )
        {
          if ( ringIndex == 0 && resPartIte == result->parts_begin() )
            newPoly->setExteriorRing( qgsgeometry_cast<QgsCurve *>( ( *resPartIte )->clone() ) );
          else
            newPoly->addInteriorRing( qgsgeometry_cast<QgsCurve *>( ( *resPartIte )->clone() ) );
        }
      }
      else
      {
        if ( ringIndex == 0 )
          newPoly->setExteriorRing( qgsgeometry_cast<QgsCurve *>( inputPoly->exteriorRing()->clone() ) );
        else
          newPoly->addInteriorRing( qgsgeometry_cast<QgsCurve *>( inputPoly->interiorRing( ringIndex - 1 )->clone() ) );
      }
    }
    return newPoly;
  };
 
  std::unique_ptr<QgsAbstractGeometry> finalGeom;
  if ( geomType == Qgis::GeometryType::Line )
  {
    if ( modifiedPart >= 0 )
    {
      auto newMultiCurve = std::make_unique<QgsMultiCurve>();
      if ( qgsgeometry_cast<const QgsMultiLineString *>( inputMultiCurve ) )
        newMultiCurve = std::make_unique<QgsMultiLineString>();
 
      int partIndex = 0;
      for ( QgsMultiCurve::part_iterator partIte = inputMultiCurve->parts_begin(); partIte != inputMultiCurve->parts_end(); ++partIte )
      {
        if ( partIndex == modifiedPart )
        {
          for ( QgsAbstractGeometry::part_iterator resPartIte = result->parts_begin(); resPartIte != result->parts_end(); ++resPartIte )
          {
            newMultiCurve->addGeometry( ( *resPartIte )->clone() );
          }
        }
        else
        {
          newMultiCurve->addGeometry( ( *partIte )->clone() );
        }
        partIndex++;
      }
      finalGeom = std::move( newMultiCurve );
    }
    else
    {
      // resultGeom is already the correct result!
      finalGeom = std::move( result );
    }
  }
  else
  {
    // geomType == Qgis::GeometryType::Polygon
    if ( modifiedPart >= 0 )
    {
      auto newMultiSurface = std::make_unique<QgsMultiSurface>();
      if ( qgsgeometry_cast<const QgsMultiPolygon *>( inputMultiSurface ) )
        newMultiSurface = std::make_unique<QgsMultiPolygon>();
 
      int partIndex = 0;
      for ( QgsAbstractGeometry::part_iterator partIte = inputMultiSurface->parts_begin(); partIte != inputMultiSurface->parts_end(); ++partIte )
      {
        if ( partIndex == modifiedPart )
        {
          std::unique_ptr<QgsCurvePolygon> newCurvePoly = updatePolygon( qgsgeometry_cast<const QgsCurvePolygon *>( *partIte ), result.get(), modifiedRing );
          newMultiSurface->addGeometry( newCurvePoly.release() );
        }
        else
        {
          newMultiSurface->addGeometry( ( *partIte )->clone() );
        }
        partIndex++;
      }
      finalGeom = std::move( newMultiSurface );
    }
    else
    {
      std::unique_ptr<QgsCurvePolygon> newCurvePoly = updatePolygon( qgsgeometry_cast<const QgsCurvePolygon *>( d->geometry.get() ), result.get(), modifiedRing );
      finalGeom = std::move( newCurvePoly );
    }
  }
 
  QgsGeometry finalResult( std::move( finalGeom ) );
 
  QgsDebugMsgLevel( u"Final result Wkt: %1"_s.arg( finalResult.asWkt( 2 ) ), 3 );
 
  return finalResult;
}
 
 
QgsGeometry QgsGeometry::chamfer( int vertexIndex, double distance1, double distance2 ) const
{
  return doChamferFillet( ChamferFilletOperationType::Chamfer, vertexIndex, distance1, distance2, 0 );
}
 
QgsGeometry QgsGeometry::fillet( int vertexIndex, double radius, int segments ) const
{
  return doChamferFillet( ChamferFilletOperationType::Fillet, vertexIndex, radius, 0.0, segments );
}
 
QgsGeometry QgsGeometry::chamfer( const QgsPoint &segment1Start, const QgsPoint &segment1End, const QgsPoint &segment2Start, const QgsPoint &segment2End, double distance1, double distance2 )
{
  std::unique_ptr<QgsLineString> result( QgsGeometryUtils::createChamferGeometry( segment1Start, segment1End, segment2Start, segment2End, distance1, distance2 ) );
 
  if ( !result )
  {
    return QgsGeometry();
  }
 
  return QgsGeometry( std::move( result ) );
}
 
QgsGeometry QgsGeometry::fillet( const QgsPoint &segment1Start, const QgsPoint &segment1End, const QgsPoint &segment2Start, const QgsPoint &segment2End, double radius, int segments )
{
  std::unique_ptr<QgsAbstractGeometry> result( QgsGeometryUtils::createFilletGeometry( segment1Start, segment1End, segment2Start, segment2End, radius, segments ) );
 
  if ( !result )
  {
    return QgsGeometry();
  }
 
  return QgsGeometry( std::move( result ) );
}
 
QVector< QgsGeometry > QgsGeometry::collectSplitFeatures( const QVector< QgsGeometry> newGeoms ) const
{
  QVector< QgsGeometry> collectedNewGeoms;
  QVector< QgsGeometry> unchangedParts;
 
  for ( QgsGeometry newGeom : newGeoms )
  {
    bool inOriginalCollection = false;
    QVector< QgsGeometry > originalGeoms = this->asGeometryCollection();
    for ( QgsGeometry &originalPart : originalGeoms )
    {
      if ( newGeom.isExactlyEqual( originalPart ) )
      {
        inOriginalCollection = true;
        break;
      }
    }
    if ( inOriginalCollection )
    {
      unchangedParts.append( newGeom );
    }
    else
    {
      // Parts that were split are added to a single multi-part geometry.
      newGeom.convertToMultiType();
      collectedNewGeoms.append( newGeom );
    }
  }
 
  // All unchanged parts are added to the same multi-geometry.
  if ( !unchangedParts.empty() )
  {
    collectedNewGeoms.prepend( QgsGeometry::collectGeometry( unchangedParts ) );
  }
  return collectedNewGeoms;
}
 
QVector< QgsGeometry > QgsGeometry::collectSplitParts( const QVector< QgsGeometry> newGeoms ) const
{
  QVector< QgsGeometry> collectedNewGeoms;
  for ( const QgsGeometry &newGeom : newGeoms )
  {
    collectedNewGeoms.append( QgsGeometry::collectGeometry( QVector< QgsGeometry>() << newGeom ) );
  }
  return collectedNewGeoms;
}
 
QVector< QgsGeometry > QgsGeometry::collectSplitGeometries( const QVector< QgsGeometry> newGeomsTemp, const bool splitFeature )
{
  QVector< QgsGeometry> newGeoms;
  if ( !newGeomsTemp.isEmpty() )
  {
    if ( this->isMultipart() && QgsWkbTypes::geometryType( this->wkbType() ) != Qgis::GeometryType::Unknown )
    {
      newGeoms = splitFeature ? collectSplitFeatures( newGeomsTemp ) : collectSplitParts( newGeomsTemp );
    }
    else
    {
      newGeoms = newGeomsTemp;
    }
 
    if ( splitFeature && !newGeoms.isEmpty() )
    {
      *this = newGeoms.takeAt( 0 );
    }
  }
  return newGeoms;
}