qgsdxfexport.cpp

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/***************************************************************************
                         qgsdxfexport.cpp
                         ----------------
    begin                : September 2013
    copyright            : (C) 2013 by Marco Hugentobler
    email                : marco at sourcepole dot ch
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
// Specs:
// AutoCAD 2000: http://www.autodesk.com/techpubs/autocad/acad2000/dxf/
// AutoCAD 2002: http://www.autodesk.com/techpubs/autocad/dxf/dxf2002.pdf
// AutoCAD 2004: http://atrey.karlin.mff.cuni.cz/projekty/vrr/doc/dxf14.pdf
// AutoCAD 2006: http://images.autodesk.com/adsk/files/dxf_format.pdf
// AutoCAD 2008: http://images.autodesk.com/adsk/files/acad_dxf0.pdf
// AutoCAD 2009: http://images.autodesk.com/adsk/files/acad_dxf.pdf
// AutoCAD 2011: http://images.autodesk.com/adsk/files/acad_dxf2.pdf
// AutoCAD 2012: http://images.autodesk.com/adsk/files/autocad_2012_pdf_dxf-reference_enu.pdf
// AutoCAD 2014: http://images.autodesk.com/adsk/files/autocad_2014_pdf_dxf_reference_enu.pdf
 
#include "qgsdxfexport.h"
 
#include "pal/feature.h"
#include "pal/labelposition.h"
#include "qgscircularstring.h"
#include "qgscompoundcurve.h"
#include "qgscurvepolygon.h"
#include "qgsdxfexport_p.h"
#include "qgsexpressioncontextutils.h"
#include "qgsfeatureiterator.h"
#include "qgsgeometrycollection.h"
#include "qgsgeometrygeneratorsymbollayer.h"
#include "qgsgeos.h"
#include "qgslinestring.h"
#include "qgslinesymbollayer.h"
#include "qgslogger.h"
#include "qgspoint.h"
#include "qgspointxy.h"
#include "qgsproject.h"
#include "qgsrenderer.h"
#include "qgssymbol.h"
#include "qgssymbollayer.h"
#include "qgssymbollayerutils.h"
#include "qgstextlabelfeature.h"
#include "qgsunittypes.h"
#include "qgsvariantutils.h"
#include "qgsvectorlayer.h"
#include "qgswkbtypes.h"
 
#include <QIODevice>
#include <QString>
#include <QTextCodec>
 
using namespace Qt::StringLiterals;
 
#ifdef _MSC_VER
#define strcasecmp( a, b ) stricmp( a, b )
#endif
 
QgsDxfExport::QgsDxfExport() = default;
 
QgsDxfExport::~QgsDxfExport()
{
  qDeleteAll( mJobs );
}
 
void QgsDxfExport::setMapSettings( const QgsMapSettings &settings )
{
  mMapSettings = settings;
}
 
void QgsDxfExport::setFlags( QgsDxfExport::Flags flags )
{
  mFlags = flags;
}
 
QgsDxfExport::Flags QgsDxfExport::flags() const
{
  return mFlags;
}
 
void QgsDxfExport::addLayers( const QList<DxfLayer> &layers )
{
  mLayerList.clear();
  mLayerNameAttribute.clear();
  mLayerOverriddenName.clear();
 
  mLayerList.reserve( layers.size() );
  for ( const DxfLayer &dxfLayer : layers )
  {
    mLayerList << dxfLayer.layer();
    if ( dxfLayer.layerOutputAttributeIndex() >= 0 )
    {
      mLayerNameAttribute.insert( dxfLayer.layer()->id(), dxfLayer.layerOutputAttributeIndex() );
    }
    if ( dxfLayer.buildDataDefinedBlocks() )
    {
      mLayerDDBlockMaxNumberOfClasses.insert( dxfLayer.layer()->id(), dxfLayer.dataDefinedBlocksMaximumNumberOfClasses() );
    }
    if ( !dxfLayer.overriddenName().isEmpty() )
    {
      mLayerOverriddenName.insert( dxfLayer.layer()->id(), dxfLayer.overriddenName() );
    }
  }
}
 
void QgsDxfExport::writeGroup( int code, int i )
{
  writeGroupCode( code );
  writeInt( i );
}
 
void QgsDxfExport::writeGroup( int code, long long i )
{
  writeGroupCode( code );
  writeInt( i );
}
 
void QgsDxfExport::writeGroup( int code, double d )
{
  writeGroupCode( code );
  writeDouble( d );
}
 
void QgsDxfExport::writeGroup( int code, const QString &s )
{
  writeGroupCode( code );
  writeString( s );
}
 
void QgsDxfExport::writeGroup( int code, const QgsPoint &p )
{
  writeGroup( code + 10, p.x() );
  writeGroup( code + 20, p.y() );
  if ( !mForce2d && p.is3D() && std::isfinite( p.z() ) )
    writeGroup( code + 30, p.z() );
}
 
void QgsDxfExport::writeGroup( const QColor &color, int exactMatchCode, int rgbCode, int transparencyCode )
{
  int minDistAt = -1;
  int minDist = std::numeric_limits<int>::max();
 
  for ( int i = 1; i < static_cast< int >( sizeof( sDxfColors ) / sizeof( *sDxfColors ) ) && minDist > 0; ++i )
  {
    int dist = color_distance( color.rgba(), i );
    if ( dist >= minDist )
      continue;
 
    minDistAt = i;
    minDist = dist;
  }
 
  if ( minDist == 0 && minDistAt != 7 )
  {
    // exact full opaque match, not black/white
    writeGroup( exactMatchCode, minDistAt );
    if ( color.alpha() == 255 )
      return;
  }
 
  int c = ( color.red() & 0xff ) * 0x10000 + ( color.green() & 0xff ) * 0x100 + ( color.blue() & 0xff );
  writeGroup( rgbCode, c );
  if ( transparencyCode != -1 && color.alpha() < 255 )
    writeGroup( transparencyCode, 0x2000000 | color.alpha() );
}
 
void QgsDxfExport::writeGroupCode( int code )
{
  mTextStream << u"%1\n"_s.arg( code, 3, 10, QChar( ' ' ) );
}
 
void QgsDxfExport::writeInt( int i )
{
  mTextStream << u"%1\n"_s.arg( i, 6, 10, QChar( ' ' ) );
}
 
void QgsDxfExport::writeDouble( double d )
{
  QString s( qgsDoubleToString( d ) );
  if ( !s.contains( '.' ) )
    s += ".0"_L1;
  mTextStream << s << '\n';
}
 
void QgsDxfExport::writeString( const QString &s )
{
  mTextStream << s << '\n';
}
 
QgsDxfExport::ExportResult QgsDxfExport::writeToFile( QIODevice *d, const QString &encoding )
{
  if ( !d )
  {
    return ExportResult::InvalidDeviceError;
  }
 
  if ( !d->isOpen() && !d->open( QIODevice::WriteOnly | QIODevice::Truncate ) )
  {
    return ExportResult::DeviceNotWritableError;
  }
 
  mTextStream.setDevice( d );
  mTextStream.setEncoding( QStringConverter::encodingForName( encoding.toLocal8Bit() ).value_or( QStringConverter::Utf8 ) );
 
  if ( mCrs.isValid() )
    mMapSettings.setDestinationCrs( mCrs );
 
  if ( mExtent.isEmpty() )
  {
    QgsRectangle extent;
    for ( QgsMapLayer *ml : std::as_const( mLayerList ) )
    {
      QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( ml );
      if ( !vl )
        continue;
 
      QgsRectangle layerExtent = vl->extent();
      if ( layerExtent.isEmpty() )
        continue;
 
      layerExtent = mMapSettings.layerToMapCoordinates( vl, layerExtent );
 
      if ( extent.isEmpty() )
      {
        extent = layerExtent;
      }
      else
      {
        extent.combineExtentWith( layerExtent );
      }
    }
    mMapSettings.setExtent( extent );
  }
  else
  {
    mMapSettings.setExtent( mExtent );
  }
 
  if ( mMapSettings.extent().isEmpty() )
    return ExportResult::EmptyExtentError;
 
  Qgis::DistanceUnit mapUnits = mCrs.isValid() ? mCrs.mapUnits() : mMapSettings.destinationCrs().mapUnits();
 
  // Empty layer check to avoid adding those in the exported file
  QList<QgsMapLayer *> layers;
  QStringList skippedLayers;
  for ( QgsMapLayer *ml : std::as_const( mLayerList ) )
  {
    QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( ml );
    if ( !vl )
    {
      continue;
    }
 
    QgsFeatureRequest request;
    request.setLimit( 1 );
    if ( !mExtent.isEmpty() )
    {
      const QgsRectangle extentRect = mMapSettings.mapToLayerCoordinates( vl, mExtent );
      request.setFilterRect( extentRect );
    }
    // cppcheck-suppress accessMoved
    QgsFeatureIterator featureIt = ( mFlags & FlagOnlySelectedFeatures ) ? vl->getSelectedFeatures( std::move( request ) ) : vl->getFeatures( std::move( request ) );
    // cppcheck-suppress accessMoved
    QgsFeature feature;
    if ( featureIt.nextFeature( feature ) )
    {
      layers << ml;
    }
    else
    {
      skippedLayers << ml->name();
    }
  }
  mMapSettings.setLayers( layers );
 
  int dpi = 96;
  mFactor = 1000 * dpi / mSymbologyScale / 25.4 * QgsUnitTypes::fromUnitToUnitFactor( mapUnits, Qgis::DistanceUnit::Meters );
  mMapSettings.setOutputSize( QSize( std::floor( mMapSettings.extent().width() * mFactor ), std::floor( mMapSettings.extent().height() * mFactor ) ) );
  mMapSettings.setOutputDpi( dpi );
 
  writeHeader( dxfEncoding( encoding ) );
  prepareRenderers();
  createDDBlockInfo();
  writeTables();
  writeBlocks();
  writeEntities();
  writeEndFile();
  stopRenderers();
 
  if ( !skippedLayers.isEmpty() )
  {
    mFeedbackMessage = QObject::tr( "The following empty layers were skipped: %1" ).arg( skippedLayers.join( ", "_L1 ) );
  }
 
  return ExportResult::Success;
}
 
Qgis::DistanceUnit QgsDxfExport::mapUnits() const
{
  return mMapUnits;
}
 
void QgsDxfExport::writeHeader( const QString &codepage )
{
  writeGroup( 999, u"DXF created from QGIS"_s );
 
  startSection();
  writeGroup( 2, u"HEADER"_s );
 
  // ACADVER
  writeGroup( 9, u"$ACADVER"_s );
  writeGroup( 1, u"AC1018"_s );
 
  // EXTMIN
  writeGroup( 9, u"$EXTMIN"_s );
  writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, mMapSettings.extent().xMinimum(), mMapSettings.extent().yMinimum(), 0.0 ) );
 
  // EXTMAX
  writeGroup( 9, u"$EXTMAX"_s );
  writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, mMapSettings.extent().xMaximum(), mMapSettings.extent().yMaximum(), 0.0 ) );
 
  // Global linetype scale
  writeGroup( 9, u"$LTSCALE"_s );
  writeGroup( 40, 1.0 );
 
  // Point display mode (33 = circle)
  writeGroup( 9, u"$PDMODE"_s );
  writeGroup( 70, 33 );
 
  // Point display size
  writeGroup( 9, u"$PDSIZE"_s );
  writeGroup( 40, 1 );
 
  // Controls paper space linetype scaling (1 = No special linetype scaling, 0 = Viewport scaling governs linetype scaling)
  writeGroup( 9, u"$PSLTSCALE"_s );
  writeGroup( 70, 0 );
 
  writeGroup( 9, u"$HANDSEED"_s );
  writeGroup( 5, DXF_HANDMAX );
 
  writeGroup( 9, u"$DWGCODEPAGE"_s );
  writeGroup( 3, codepage );
 
  endSection();
}
 
int QgsDxfExport::writeHandle( int code, int handle )
{
  if ( handle == 0 )
    handle = mNextHandleId++;
 
  Q_ASSERT_X( handle < DXF_HANDMAX, "QgsDxfExport::writeHandle(int, int)", "DXF handle too large" );
 
  writeGroup( code, QString::number( handle, 16 ) );
  return handle;
}
 
void QgsDxfExport::writeTables()
{
  startSection();
  writeGroup( 2, u"TABLES"_s );
 
  // Iterate through all layers and get symbol layer pointers
  QgsRenderContext context = renderContext();
  QList< QPair< QgsSymbolLayer *, QgsSymbol * > > slList;
  switch ( mSymbologyExport )
  {
    case Qgis::FeatureSymbologyExport::PerFeature:
    case Qgis::FeatureSymbologyExport::PerSymbolLayer:
    {
      slList = symbolLayers( context );
      break;
    }
 
    case Qgis::FeatureSymbologyExport::NoSymbology:
      break;
  }
 
  // Line types
  mLineStyles.clear();
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"LTYPE"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTable"_s );
  writeGroup( 70, nLineTypes( slList ) + 5 );
 
  writeDefaultLinetypes();
 
  // Add custom linestyles
  for ( const auto &symbolLayer : std::as_const( slList ) )
  {
    writeSymbolLayerLinetype( symbolLayer.first );
  }
 
  writeGroup( 0, u"ENDTAB"_s );
 
  // BLOCK_RECORD
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"BLOCK_RECORD"_s );
  writeHandle();
 
  writeGroup( 100, u"AcDbSymbolTable"_s );
  writeGroup( 70, 0 );
 
  const QStringList blockStrings = QStringList() << u"*Model_Space"_s << u"*Paper_Space"_s << u"*Paper_Space0"_s;
  for ( const QString &block : blockStrings )
  {
    writeGroup( 0, u"BLOCK_RECORD"_s );
    mBlockHandles.insert( block, writeHandle() );
    writeGroup( 100, u"AcDbSymbolTableRecord"_s );
    writeGroup( 100, u"AcDbBlockTableRecord"_s );
    writeGroup( 2, block );
  }
 
  int i = 0;
  for ( const auto &symbolLayer : std::as_const( slList ) )
  {
    QgsMarkerSymbolLayer *ml = dynamic_cast< QgsMarkerSymbolLayer *>( symbolLayer.first );
    if ( !ml )
      continue;
 
    if ( hasBlockBreakingDataDefinedProperties( ml, symbolLayer.second ) )
    {
      //reference to symbology class from mDataDefinedBlockInfo?
      if ( !mDataDefinedBlockInfo.contains( ml ) )
      {
        continue;
      }
 
      const QHash<uint, DataDefinedBlockInfo> &symbolClasses = mDataDefinedBlockInfo[ml];
      for ( const auto &blockInfo : symbolClasses )
      {
        writeSymbolTableBlockRef( blockInfo.blockName );
      }
 
      ++i;
      continue;
    }
 
    QString name = u"symbolLayer%1"_s.arg( i++ );
    writeSymbolTableBlockRef( name );
  }
 
  writeGroup( 0, u"ENDTAB"_s );
 
  // APPID
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"APPID"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTable"_s );
  writeGroup( 70, 1 );
  writeGroup( 0, u"APPID"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTableRecord"_s );
  writeGroup( 100, u"AcDbRegAppTableRecord"_s );
  writeGroup( 2, u"ACAD"_s );
  writeGroup( 70, 0 );
  writeGroup( 0, u"ENDTAB"_s );
 
  // VIEW
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"VIEW"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTable"_s );
  writeGroup( 70, 0 );
  writeGroup( 0, u"ENDTAB"_s );
 
  // UCS
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"UCS"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTable"_s );
  writeGroup( 70, 0 );
  writeGroup( 0, u"ENDTAB"_s );
 
  // VPORT
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"VPORT"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTable"_s );
 
  writeGroup( 0, u"VPORT"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTableRecord"_s );
  writeGroup( 100, u"AcDbViewportTableRecord"_s );
  writeGroup( 2, u"*ACTIVE"_s );
  writeGroup( 70, 0 );                                                              // flags
  writeGroup( 0, QgsPoint( 0.0, 0.0 ) );                                            // lower left
  writeGroup( 1, QgsPoint( 1.0, 1.0 ) );                                            // upper right
  writeGroup( 2, QgsPoint( 0.0, 0.0 ) );                                            // view center point
  writeGroup( 3, QgsPoint( 0.0, 0.0 ) );                                            // snap base point
  writeGroup( 4, QgsPoint( 1.0, 1.0 ) );                                            // snap spacing
  writeGroup( 5, QgsPoint( 1.0, 1.0 ) );                                            // grid spacing
  writeGroup( 6, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 1.0 ) );                // view direction from target point
  writeGroup( 7, QgsPoint( mMapSettings.extent().center() ) );                      // view target point
  writeGroup( 40, mMapSettings.extent().height() );                                 // view height
  writeGroup( 41, mMapSettings.extent().width() / mMapSettings.extent().height() ); // view aspect ratio
  writeGroup( 42, 50.0 );                                                           // lens length
  writeGroup( 43, 0.0 );                                                            // front clipping plane
  writeGroup( 44, 0.0 );                                                            // back clipping plane
  writeGroup( 50, 0.0 );                                                            // snap rotation
  writeGroup( 51, 0.0 );                                                            // view twist angle
  writeGroup( 71, 0 );                                                              // view mode (0 = deactivates)
  writeGroup( 72, 100 );                                                            // circle zoom percent
  writeGroup( 73, 1 );                                                              // fast zoom setting
  writeGroup( 74, 1 );                                                              // UCSICON setting
  writeGroup( 75, 0 );                                                              // snapping off
  writeGroup( 76, 0 );                                                              // grid off
  writeGroup( 77, 0 );                                                              // snap style
  writeGroup( 78, 0 );                                                              // snap isopair
  writeGroup( 281, 0 );                                                             // render mode (0 = 2D optimized)
  writeGroup( 65, 1 );                                                              // value of UCSVP for this viewport
  writeGroup( 100, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 0.0 ) );              // UCS origin
  writeGroup( 101, QgsPoint( Qgis::WkbType::PointZ, 1.0, 0.0, 0.0 ) );              // UCS x axis
  writeGroup( 102, QgsPoint( Qgis::WkbType::PointZ, 0.0, 1.0, 0.0 ) );              // UCS y axis
  writeGroup( 79, 0 );                                                              // Orthographic type of UCS (0 = UCS is not orthographic)
  writeGroup( 146, 0.0 );                                                           // Elevation
 
  writeGroup( 70, 0 );
  writeGroup( 0, u"ENDTAB"_s );
 
  // DIMSTYLE
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"DIMSTYLE"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTable"_s );
  writeGroup( 100, u"AcDbDimStyleTable"_s );
  writeGroup( 70, 0 );
  writeGroup( 0, u"ENDTAB"_s );
 
  QSet<QString> layerNames;
  const QList< QgsMapLayer * > layers = mMapSettings.layers();
  for ( QgsMapLayer *ml : layers )
  {
    if ( !layerIsScaleBasedVisible( ml ) )
      continue;
 
    QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( ml );
    if ( !vl )
      continue;
 
    int attrIdx = mLayerNameAttribute.value( vl->id(), -1 );
    if ( attrIdx < 0 )
    {
      layerNames << dxfLayerName( layerName( vl ) );
    }
    else
    {
      const QSet<QVariant> values = vl->uniqueValues( attrIdx );
      for ( const QVariant &v : values )
      {
        layerNames << dxfLayerName( v.toString() );
      }
    }
  }
 
  // Layers
  // TODO: iterate features of all layer to produce a data-defined layer list
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"LAYER"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTable"_s );
  writeGroup( 70, layerNames.size() + 1 );
 
  writeGroup( 0, u"LAYER"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTableRecord"_s );
  writeGroup( 100, u"AcDbLayerTableRecord"_s );
  writeGroup( 2, u"0"_s );
  writeGroup( 70, 64 );
  writeGroup( 62, 1 );
  writeGroup( 6, u"CONTINUOUS"_s );
  writeHandle( 390, DXF_HANDPLOTSTYLE );
 
  for ( const QString &layerName : std::as_const( layerNames ) )
  {
    writeGroup( 0, u"LAYER"_s );
    writeHandle();
    writeGroup( 100, u"AcDbSymbolTableRecord"_s );
    writeGroup( 100, u"AcDbLayerTableRecord"_s );
    writeGroup( 2, layerName );
    writeGroup( 70, 64 );
    writeGroup( 62, 1 );
    writeGroup( 6, u"CONTINUOUS"_s );
    writeHandle( 390, DXF_HANDPLOTSTYLE );
  }
  writeGroup( 0, u"ENDTAB"_s );
 
  // Text styles
  writeGroup( 0, u"TABLE"_s );
  writeGroup( 2, u"STYLE"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTable"_s );
  writeGroup( 70, 1 );
 
  // Provide only standard font for the moment
  writeGroup( 0, u"STYLE"_s );
  writeHandle();
  writeGroup( 100, u"AcDbSymbolTableRecord"_s );
  writeGroup( 100, u"AcDbTextStyleTableRecord"_s );
  writeGroup( 2, u"STANDARD"_s );
  writeGroup( 70, 64 );
  writeGroup( 40, 0.0 );
  writeGroup( 41, 1.0 );
  writeGroup( 50, 0.0 );
  writeGroup( 71, 0 );
  writeGroup( 42, 5.0 );
  writeGroup( 3, u"romans.shx"_s );
  writeGroup( 4, QString() );
 
  writeGroup( 0, u"ENDTAB"_s );
 
  endSection();
}
 
void QgsDxfExport::writeSymbolTableBlockRef( const QString &blockName )
{
  writeGroup( 0, u"BLOCK_RECORD"_s );
  mBlockHandles.insert( blockName, writeHandle() );
  writeGroup( 100, u"AcDbSymbolTableRecord"_s );
  writeGroup( 100, u"AcDbBlockTableRecord"_s );
  writeGroup( 2, blockName );
}
 
void QgsDxfExport::writeBlocks()
{
  startSection();
  writeGroup( 2, u"BLOCKS"_s );
 
  static const QStringList blockStrings = QStringList() << u"*Model_Space"_s << u"*Paper_Space"_s << u"*Paper_Space0"_s;
  for ( const QString &block : blockStrings )
  {
    writeGroup( 0, u"BLOCK"_s );
    writeHandle();
    writeGroup( 330, QString::number( mBlockHandles[block], 16 ) );
    writeGroup( 100, u"AcDbEntity"_s );
    writeGroup( 8, u"0"_s );
    writeGroup( 100, u"AcDbBlockBegin"_s );
    writeGroup( 2, block );
    writeGroup( 70, 0 );
    writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 0.0 ) );
    writeGroup( 3, block );
    writeGroup( 1, QString() );
    writeGroup( 0, u"ENDBLK"_s );
    writeHandle();
    writeGroup( 100, u"AcDbEntity"_s );
    writeGroup( 8, u"0"_s );
    writeGroup( 100, u"AcDbBlockEnd"_s );
  }
 
  QgsRenderContext ct = renderContext();
 
  // Iterate through all layers and get symbol layer pointers
  QList< QPair< QgsSymbolLayer *, QgsSymbol * > > slList;
  switch ( mSymbologyExport )
  {
    case Qgis::FeatureSymbologyExport::PerFeature:
    case Qgis::FeatureSymbologyExport::PerSymbolLayer:
    {
      slList = symbolLayers( ct );
      break;
    }
    case Qgis::FeatureSymbologyExport::NoSymbology:
      break;
  }
 
  for ( const auto &symbolLayer : std::as_const( slList ) )
  {
    QgsMarkerSymbolLayer *ml = dynamic_cast< QgsMarkerSymbolLayer *>( symbolLayer.first );
    if ( !ml )
      continue;
 
    // if point symbol layer and no data defined properties: write block
    QgsSymbolRenderContext ctx( ct, Qgis::RenderUnit::MapUnits, symbolLayer.second->opacity(), false, symbolLayer.second->renderHints(), nullptr );
 
    // markers with data defined properties are inserted inline
    if ( hasBlockBreakingDataDefinedProperties( ml, symbolLayer.second ) )
    {
      if ( !mDataDefinedBlockInfo.contains( ml ) )
      {
        continue;
      }
 
      //Check if there is an entry for the symbol layer in mDataDefinedBlockInfo
      const QHash<uint, DataDefinedBlockInfo> &symbolClasses = mDataDefinedBlockInfo[ml];
      for ( const auto &blockInfo : symbolClasses )
      {
        ctx.setFeature( &blockInfo.feature );
        ctx.renderContext().expressionContext().setFeature( blockInfo.feature );
        writeSymbolLayerBlock( blockInfo.blockName, ml, ctx );
      }
 
      ++mBlockCounter;
      continue;
    }
 
    QString block( u"symbolLayer%1"_s.arg( mBlockCounter++ ) );
    writeSymbolLayerBlock( block, ml, ctx );
 
    mPointSymbolBlocks.insert( ml, block );
    mPointSymbolBlockSizes.insert( ml, ml->dxfSize( ctx ) );
    mPointSymbolBlockAngles.insert( ml, ml->dxfAngle( ctx ) );
  }
  endSection();
}
 
void QgsDxfExport::writeSymbolLayerBlock( const QString &blockName, const QgsMarkerSymbolLayer *ml, QgsSymbolRenderContext &ctx )
{
  mBlockHandle = QString::number( mBlockHandles[blockName], 16 );
  writeGroup( 0, u"BLOCK"_s );
  writeHandle();
  writeGroup( 330, mBlockHandle );
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 8, u"0"_s );
  writeGroup( 100, u"AcDbBlockBegin"_s );
  writeGroup( 2, blockName );
  writeGroup( 70, 0 );
 
  // x/y/z coordinates of reference point
  // todo: consider anchor point
  // double size = ml->size();
  // size *= mapUnitScaleFactor( mSymbologyScale, ml->sizeUnit(), mMapUnits );
  writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 0.0 ) );
  writeGroup( 3, blockName );
 
  writeGroup( 1, QString() );
 
  // maplayer 0 -> block receives layer from INSERT statement
  ml->writeDxf( *this, mapUnitScaleFactor( ctx.renderContext(), ml->sizeUnit() ), u"0"_s, ctx );
 
  writeGroup( 0, u"ENDBLK"_s );
  writeHandle();
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 8, u"0"_s );
  writeGroup( 100, u"AcDbBlockEnd"_s );
}
 
void QgsDxfExport::writeEntities()
{
  startSection();
  writeGroup( 2, u"ENTITIES"_s );
 
  mBlockHandle = QString::number( mBlockHandles[u"*Model_Space"_s], 16 );
 
  // iterate through the maplayers
  for ( DxfLayerJob *job : std::as_const( mJobs ) )
  {
    QgsSymbolRenderContext sctx( job->renderContext, Qgis::RenderUnit::Millimeters, 1.0, false, Qgis::SymbolRenderHints(), nullptr );
 
    if ( mSymbologyExport == Qgis::FeatureSymbologyExport::PerSymbolLayer && ( job->renderer->capabilities() & QgsFeatureRenderer::SymbolLevels ) && job->renderer->usingSymbolLevels() )
    {
      writeEntitiesSymbolLevels( job );
 
      continue;
    }
 
    const QgsCoordinateTransform ct( job->crs, mMapSettings.destinationCrs(), mMapSettings.transformContext() );
 
    QgsFeatureRequest request = QgsFeatureRequest().setSubsetOfAttributes( job->attributes, job->fields ).setExpressionContext( job->renderContext.expressionContext() );
    QgsCoordinateTransform extentTransform = ct;
    extentTransform.setBallparkTransformsAreAppropriate( true );
 
    try
    {
      request.setFilterRect( extentTransform.transformBoundingBox( mMapSettings.extent(), Qgis::TransformDirection::Reverse ) );
    }
    catch ( QgsCsException &e )
    {
      QgsDebugError( u"Error transforming DXF layer extent: %1"_s.arg( e.what() ) );
      continue;
    }
 
    if ( mFlags & FlagOnlySelectedFeatures )
    {
      request.setFilterFids( job->selectedFeatureIds );
    }
 
    QgsFeatureIterator featureIt = job->featureSource.getFeatures( request );
 
    QgsFeature fet;
    while ( featureIt.nextFeature( fet ) )
    {
      job->renderContext.expressionContext().setFeature( fet );
      QString lName( dxfLayerName( job->splitLayerAttribute.isNull() ? job->layerDerivedName : fet.attribute( job->splitLayerAttribute ).toString() ) );
 
      sctx.setFeature( &fet );
 
      if ( !job->renderer->willRenderFeature( fet, job->renderContext ) )
        continue;
 
      if ( mSymbologyExport == Qgis::FeatureSymbologyExport::NoSymbology )
      {
        addFeature( sctx, ct, lName, nullptr, nullptr ); // no symbology at all
      }
      else
      {
        const QgsSymbolList symbolList = job->renderer->symbolsForFeature( fet, job->renderContext );
        bool hasSymbology = symbolList.size() > 0;
 
        if ( hasSymbology && mSymbologyExport == Qgis::FeatureSymbologyExport::PerSymbolLayer ) // symbol layer symbology, but layer does not use symbol levels
        {
          for ( QgsSymbol *symbol : symbolList )
          {
            const QgsSymbolLayerList symbolLayers = symbol->symbolLayers();
            for ( QgsSymbolLayer *symbolLayer : symbolLayers )
            {
              if ( !symbolLayer )
                continue;
 
              if ( !isSymbolLayerEnabled( symbolLayer, sctx ) )
                continue;
 
              bool isGeometryGenerator = ( symbolLayer->layerType() == "GeometryGenerator"_L1 );
              if ( isGeometryGenerator )
              {
                addGeometryGeneratorSymbolLayer( sctx, ct, lName, symbolLayer, true );
              }
              else
              {
                addFeature( sctx, ct, lName, symbolLayer, symbol );
              }
            }
          }
        }
        else if ( hasSymbology )
        {
          // take first symbollayer from first symbol
          QgsSymbol *s = symbolList.first();
          if ( !s || s->symbolLayerCount() < 1 )
          {
            continue;
          }
 
          if ( !isSymbolLayerEnabled( s->symbolLayer( 0 ), sctx ) )
          {
            continue;
          }
 
          if ( s->symbolLayer( 0 )->layerType() == "GeometryGenerator"_L1 )
          {
            addGeometryGeneratorSymbolLayer( sctx, ct, lName, s->symbolLayer( 0 ), false );
          }
          else
          {
            addFeature( sctx, ct, lName, s->symbolLayer( 0 ), s );
          }
        }
 
        if ( job->labelProvider )
        {
          job->labelProvider->registerFeature( fet, job->renderContext );
          Q_NOWARN_DEPRECATED_PUSH
          registerDxfLayer( job->featureSource.id(), fet.id(), lName );
          Q_NOWARN_DEPRECATED_POP
        }
        else if ( job->ruleBasedLabelProvider )
        {
          job->ruleBasedLabelProvider->registerFeature( fet, job->renderContext );
          Q_NOWARN_DEPRECATED_PUSH
          registerDxfLayer( job->featureSource.id(), fet.id(), lName );
          Q_NOWARN_DEPRECATED_POP
        }
      }
    }
  }
 
  QImage image( 10, 10, QImage::Format_ARGB32_Premultiplied );
  image.setDotsPerMeterX( 96 / 25.4 * 1000 );
  image.setDotsPerMeterY( 96 / 25.4 * 1000 );
  QPainter painter( &image );
  mRenderContext.setPainter( &painter );
 
  mRenderContext.labelingEngine()->run( mRenderContext );
 
  endSection();
}
 
void QgsDxfExport::prepareRenderers()
{
  Q_ASSERT( mJobs.empty() ); // If this fails, stopRenderers() was not called after the last job
 
  mRenderContext = QgsRenderContext();
  mRenderContext.setPathResolver( mMapSettings.pathResolver() );
  mRenderContext.setRendererScale( mSymbologyScale );
  mRenderContext.setExtent( mMapSettings.extent() );
  QgsDistanceArea da;
  da.setSourceCrs( mMapSettings.destinationCrs(), mMapSettings.transformContext() );
  da.setEllipsoid( mMapSettings.ellipsoid() );
  mRenderContext.setDistanceArea( da );
  mRenderContext.setScaleFactor( 96.0 / 25.4 );
  mRenderContext.setMapToPixel(
    QgsMapToPixel( 1.0 / mFactor, mMapSettings.extent().center().x(), mMapSettings.extent().center().y(), std::floor( mMapSettings.extent().width() * mFactor ), std::floor( mMapSettings.extent().height() * mFactor ), 0 )
  );
 
  mRenderContext.expressionContext().appendScope( QgsExpressionContextUtils::projectScope( QgsProject::instance() ) ); // skip-keyword-check
  mRenderContext.expressionContext().appendScope( QgsExpressionContextUtils::globalScope() );
  mRenderContext.expressionContext().appendScope( QgsExpressionContextUtils::mapSettingsScope( mMapSettings ) );
 
  mLabelingEngine = std::make_unique<QgsDefaultLabelingEngine>();
  mLabelingEngine->setMapSettings( mMapSettings );
  mRenderContext.setLabelingEngine( mLabelingEngine.get() );
 
  const QList< QgsMapLayer * > layers = mMapSettings.layers();
  for ( QgsMapLayer *ml : layers )
  {
    QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( ml );
    if ( !vl )
      continue;
 
    if ( !vl->renderer() )
      continue;
 
    if ( !layerIsScaleBasedVisible( vl ) )
      continue;
 
    QString splitLayerAttribute;
    int splitLayerAttributeIndex = mLayerNameAttribute.value( vl->id(), -1 );
    const QgsFields fields = vl->fields();
    if ( splitLayerAttributeIndex >= 0 && splitLayerAttributeIndex < fields.size() )
      splitLayerAttribute = fields.at( splitLayerAttributeIndex ).name();
    DxfLayerJob *job = new DxfLayerJob( vl, mMapSettings.layerStyleOverrides().value( vl->id() ), mRenderContext, this, splitLayerAttribute, layerName( vl ) );
    mJobs.append( job );
  }
}
 
void QgsDxfExport::writeEntitiesSymbolLevels( DxfLayerJob *job )
{
  QHash< QgsSymbol *, QList<QgsFeature> > features;
 
  QgsRenderContext ctx = renderContext();
  const QList<QgsExpressionContextScope *> scopes = job->renderContext.expressionContext().scopes();
  for ( QgsExpressionContextScope *scope : scopes )
    ctx.expressionContext().appendScope( new QgsExpressionContextScope( *scope ) );
  QgsSymbolRenderContext sctx( ctx, Qgis::RenderUnit::Millimeters, 1.0, false, Qgis::SymbolRenderHints(), nullptr );
 
  // get iterator
  QgsFeatureRequest req;
  req.setSubsetOfAttributes( job->renderer->usedAttributes( ctx ), job->featureSource.fields() );
  QgsCoordinateTransform ct( mMapSettings.destinationCrs(), job->crs, mMapSettings.transformContext() );
  try
  {
    req.setFilterRect( ct.transform( mMapSettings.extent() ) );
  }
  catch ( const QgsCsException & )
  {
    QgsDebugError( u"QgsDxfExport::writeEntitiesSymbolLevels(): extent reprojection failed"_s );
    return;
  }
  if ( mFlags & FlagOnlySelectedFeatures )
  {
    req.setFilterFids( job->selectedFeatureIds );
  }
 
  QgsFeatureIterator fit = job->featureSource.getFeatures( req );
 
  // fetch features
  QgsFeature fet;
  QgsSymbol *featureSymbol = nullptr;
  while ( fit.nextFeature( fet ) )
  {
    ctx.expressionContext().setFeature( fet );
    featureSymbol = job->renderer->symbolForFeature( fet, ctx );
    if ( !featureSymbol )
    {
      continue;
    }
 
    QHash< QgsSymbol *, QList<QgsFeature> >::iterator it = features.find( featureSymbol );
    if ( it == features.end() )
    {
      it = features.insert( featureSymbol, QList<QgsFeature>() );
    }
    it.value().append( fet );
  }
 
  // find out order
  QgsSymbolLevelOrder levels;
  const QgsSymbolList symbols = job->renderer->symbols( ctx );
  for ( QgsSymbol *symbol : symbols )
  {
    for ( int j = 0; j < symbol->symbolLayerCount(); j++ )
    {
      int level = symbol->symbolLayer( j )->renderingPass();
      if ( level < 0 || level >= 1000 ) // ignore invalid levels
        continue;
      QgsSymbolLevelItem item( symbol, j );
      while ( level >= levels.count() ) // append new empty levels
        levels.append( QgsSymbolLevel() );
      levels[level].append( item );
    }
  }
 
  // export symbol layers and symbology
  for ( const QgsSymbolLevel &level : std::as_const( levels ) )
  {
    for ( const QgsSymbolLevelItem &item : level )
    {
      QHash< QgsSymbol *, QList<QgsFeature> >::iterator levelIt = features.find( item.symbol() );
      if ( levelIt == features.end() )
      {
        continue;
      }
 
      int llayer = item.layer();
      const QList<QgsFeature> &featureList = levelIt.value();
      QgsSymbolLayer *symbolLayer = levelIt.key()->symbolLayer( llayer );
      for ( const QgsFeature &feature : featureList )
      {
        sctx.setFeature( &feature );
        sctx.renderContext().expressionContext().setFeature( feature );
        if ( !isSymbolLayerEnabled( symbolLayer, sctx ) )
          continue;
        addFeature( sctx, ct, job->layerName, symbolLayer, levelIt.key() );
      }
    }
  }
}
 
void QgsDxfExport::stopRenderers()
{
  qDeleteAll( mJobs );
  mJobs.clear();
}
 
void QgsDxfExport::writeEndFile()
{
  mTextStream << DXF_TRAILER;
 
  writeGroup( 0, u"EOF"_s );
}
 
void QgsDxfExport::startSection()
{
  writeGroup( 0, u"SECTION"_s );
}
 
void QgsDxfExport::endSection()
{
  writeGroup( 0, u"ENDSEC"_s );
}
 
void QgsDxfExport::writePoint( const QgsPoint &pt, const QString &layer, const QColor &color, QgsSymbolRenderContext &ctx, const QgsSymbolLayer *symbolLayer, const QgsSymbol *symbol, double angle )
{
#if 0
  // debug: draw rectangle for debugging
  const QgsMarkerSymbolLayer *msl = dynamic_cast< const QgsMarkerSymbolLayer * >( symbolLayer );
  if ( msl )
  {
    double halfSize = msl->size() * mapUnitScaleFactor( ctx.renderContext(),
                      msl->sizeUnit() ) / 2.0;
    writeGroup( 0, "SOLID" );
    writeGroup( 8, layer );
    writeGroup( 62, 1 );
    writeGroup( 0, QgsPoint( QgsWkbTypes::PointZ, pt.x() - halfSize, pt.y() - halfSize ) );
    writeGroup( 1, QgsPoint( QgsWkbTypes::PointZ, pt.x() + halfSize, pt.y() - halfSize ) );
    writeGroup( 2, QgsPoint( QgsWkbTypes::PointZ, pt.x() - halfSize, pt.y() + halfSize ) );
    writeGroup( 3, QgsPoint( QgsWkbTypes::PointZ, pt.x() + halfSize, pt.y() + halfSize ) );
  }
#endif // 0
 
  //there is a global block for the point layer
  QHash< const QgsSymbolLayer *, QString >::const_iterator blockIt = mPointSymbolBlocks.constFind( symbolLayer );
  if ( symbolLayer && blockIt != mPointSymbolBlocks.constEnd() )
  {
    writePointBlockReference( pt, symbolLayer, ctx, layer, angle, blockIt.value(), mPointSymbolBlockAngles.value( symbolLayer ), mPointSymbolBlockSizes.value( symbolLayer ) );
    return;
  }
 
  //If there is a data defined block for the point layer, check if the feature falls into a data defined category
  QHash< const QgsSymbolLayer *, QHash<uint, DataDefinedBlockInfo> >::const_iterator ddBlockIt = mDataDefinedBlockInfo.constFind( symbolLayer );
  if ( symbolLayer && ctx.feature() && ddBlockIt != mDataDefinedBlockInfo.constEnd() )
  {
    const QHash<uint, DataDefinedBlockInfo> &symbolLayerDDBlocks = ddBlockIt.value();
 
    QgsPropertyCollection props = symbolLayer->dataDefinedProperties();
 
    uint ddSymbolHash = dataDefinedSymbolClassHash( *( ctx.feature() ), props, ctx.renderContext().expressionContext() );
    if ( symbolLayerDDBlocks.contains( ddSymbolHash ) )
    {
      const DataDefinedBlockInfo &info = symbolLayerDDBlocks[ddSymbolHash];
      writePointBlockReference( pt, symbolLayer, ctx, layer, angle, info.blockName, info.angle, info.size );
      return;
    }
  }
 
  //no block has been created for the symbol. Write it directly here
  const QgsMarkerSymbolLayer *msl = dynamic_cast< const QgsMarkerSymbolLayer * >( symbolLayer );
  if ( msl && symbol )
  {
    if ( msl->writeDxf( *this, mapUnitScaleFactor( ctx.renderContext(), msl->sizeUnit() ), layer, ctx, QPointF( pt.x(), pt.y() ) ) )
    {
      return;
    }
  }
  writePoint( layer, color, pt ); // write default point symbol
}
 
void QgsDxfExport::writePointBlockReference(
  const QgsPoint &pt, const QgsSymbolLayer *symbolLayer, QgsSymbolRenderContext &ctx, const QString &layer, double angle, const QString &blockName, double blockAngle, double blockSize
)
{
  const double scale = symbolLayer->dxfSize( ctx ) / blockSize;
 
  // insert block reference
  writeGroup( 0, u"INSERT"_s );
  writeHandle();
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 100, u"AcDbBlockReference"_s );
  writeGroup( 8, layer );
  writeGroup( 2, blockName ); // Block name
  writeGroup( 50, blockAngle - angle );
  if ( std::isfinite( scale ) && scale != 1.0 )
  {
    writeGroup( 41, scale );
    writeGroup( 42, scale );
  }
  writeGroup( 0, pt ); // Insertion point (in OCS)
}
 
uint QgsDxfExport::dataDefinedSymbolClassHash( const QgsFeature &fet, const QgsPropertyCollection &prop, const QgsExpressionContext &context )
{
  // Hash the evaluated result of each data-defined property that affects the
  // BLOCK content, not only the source attribute values.
  uint hashValue = 0;
 
  QgsExpressionContext ctx = context;
  ctx.setFeature( fet );
 
  QList<int> keys = prop.propertyKeys().values();
  keys.removeAll( static_cast<int>( QgsSymbolLayer::Property::Size ) );
  keys.removeAll( static_cast<int>( QgsSymbolLayer::Property::Angle ) );
  std::sort( keys.begin(), keys.end() ); //ensure a stable order
 
  int i = 0;
  for ( int key : std::as_const( keys ) )
  {
    const QVariant evaluated = prop.value( key, ctx );
    if ( i == 0 )
    {
      hashValue = qHash( evaluated );
    }
    else
    {
      hashValue = hashValue ^ qHash( evaluated );
    }
    ++i;
  }
 
  return hashValue;
}
 
void QgsDxfExport::writePolyline( const QgsPointSequence &line, const QString &layer, const QString &lineStyleName, const QColor &color, double width )
{
  int n = line.size();
  if ( n == 0 )
  {
    QgsDebugError( u"writePolyline: empty line layer=%1 lineStyleName=%2"_s.arg( layer, lineStyleName ) );
    return;
  }
 
  if ( n < 2 )
  {
    QgsDebugError( u"writePolyline: line too short layer=%1 lineStyleName=%2"_s.arg( layer, lineStyleName ) );
    return;
  }
 
  if ( mForce2d || !line.at( 0 ).is3D() )
  {
    bool polygon = line[0] == line[line.size() - 1];
    if ( polygon )
      --n;
 
    writeGroup( 0, u"LWPOLYLINE"_s );
    writeHandle();
    writeGroup( 8, layer );
    writeGroup( 100, u"AcDbEntity"_s );
    writeGroup( 100, u"AcDbPolyline"_s );
    writeGroup( 6, lineStyleName );
    writeGroup( color );
 
    writeGroup( 90, n );
    writeGroup( 70, polygon ? 1 : 0 );
    writeGroup( 43, width );
 
    for ( int i = 0; i < n; i++ )
      writeGroup( 0, line[i] );
  }
  else
  {
    writeGroup( 0, u"POLYLINE"_s );
    int plHandle = writeHandle();
    writeGroup( 330, mBlockHandle );
    writeGroup( 100, u"AcDbEntity"_s );
    writeGroup( 8, layer );
    writeGroup( 6, lineStyleName );
    writeGroup( color );
    writeGroup( 100, u"AcDb3dPolyline"_s );
    writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 0.0 ) );
    writeGroup( 70, 8 );
 
    for ( int i = 0; i < n; i++ )
    {
      writeGroup( 0, u"VERTEX"_s );
      writeHandle();
      writeGroup( 330, plHandle );
      writeGroup( 100, u"AcDbEntity"_s );
      writeGroup( 8, layer );
      writeGroup( color );
      writeGroup( 100, u"AcDbVertex"_s );
      writeGroup( 100, u"AcDb3dPolylineVertex"_s );
      writeGroup( 0, line[i] );
      writeGroup( 70, 32 );
    }
 
    writeGroup( 0, u"SEQEND"_s );
    writeHandle();
    writeGroup( 330, plHandle );
    writeGroup( 100, u"AcDbEntity"_s );
    writeGroup( 8, layer );
    writeGroup( color );
  }
}
 
void QgsDxfExport::appendCurve( const QgsCurve &c, QVector<QgsPoint> &points, QVector<double> &bulges )
{
  switch ( QgsWkbTypes::flatType( c.wkbType() ) )
  {
    case Qgis::WkbType::LineString:
      appendLineString( *qgis::down_cast<const QgsLineString *>( &c ), points, bulges );
      break;
 
    case Qgis::WkbType::CircularString:
      appendCircularString( *qgis::down_cast<const QgsCircularString *>( &c ), points, bulges );
      break;
 
    case Qgis::WkbType::CompoundCurve:
      appendCompoundCurve( *qgis::down_cast<const QgsCompoundCurve *>( &c ), points, bulges );
      break;
 
    default:
      QgsDebugError( u"Unexpected curve type %1"_s.arg( c.wktTypeStr() ) );
      break;
  }
}
 
void QgsDxfExport::appendLineString( const QgsLineString &ls, QVector<QgsPoint> &points, QVector<double> &bulges )
{
  for ( int i = 0; i < ls.numPoints(); i++ )
  {
    const QgsPoint &p = ls.pointN( i );
    if ( !points.isEmpty() && points.last() == p )
      continue;
 
    points << p;
    bulges << 0.0;
  }
}
 
void QgsDxfExport::appendCircularString( const QgsCircularString &cs, QVector<QgsPoint> &points, QVector<double> &bulges )
{
  for ( int i = 0; i < cs.numPoints() - 2; i += 2 )
  {
    const QgsPoint &p1 = cs.pointN( i );
    const QgsPoint &p2 = cs.pointN( i + 1 );
    const QgsPoint &p3 = cs.pointN( i + 2 );
 
    if ( points.isEmpty() || points.last() != p1 )
      points << p1;
    else if ( !bulges.isEmpty() )
      bulges.removeLast();
 
    double a = ( M_PI - ( p1 - p2 ).angle() + ( p3 - p2 ).angle() ) / 2.0;
    bulges << sin( a ) / cos( a );
 
    points << p3;
    bulges << 0.0;
  }
}
 
void QgsDxfExport::appendCompoundCurve( const QgsCompoundCurve &cc, QVector<QgsPoint> &points, QVector<double> &bulges )
{
  for ( int i = 0; i < cc.nCurves(); i++ )
  {
    const QgsCurve *c = cc.curveAt( i );
    Q_ASSERT( c );
    appendCurve( *c, points, bulges );
  }
}
 
void QgsDxfExport::writePolyline( const QgsCurve &curve, const QString &layer, const QString &lineStyleName, const QColor &color, double width )
{
  int n = curve.numPoints();
  if ( n == 0 )
  {
    QgsDebugError( u"writePolyline: empty line layer=%1 lineStyleName=%2"_s.arg( layer, lineStyleName ) );
    return;
  }
 
  if ( n < 2 )
  {
    QgsDebugError( u"writePolyline: line too short layer=%1 lineStyleName=%2"_s.arg( layer, lineStyleName ) );
    return;
  }
 
  QVector<QgsPoint> points;
  QVector<double> bulges;
  appendCurve( curve, points, bulges );
 
  if ( mForce2d || !curve.is3D() )
  {
    writeGroup( 0, u"LWPOLYLINE"_s );
    writeHandle();
    writeGroup( 8, layer );
    writeGroup( 100, u"AcDbEntity"_s );
    writeGroup( 100, u"AcDbPolyline"_s );
    writeGroup( 6, lineStyleName );
    writeGroup( color );
 
    writeGroup( 90, points.size() );
    QgsDxfExport::DxfPolylineFlags polylineFlags;
    if ( curve.isClosed() )
      polylineFlags.setFlag( QgsDxfExport::DxfPolylineFlag::Closed );
    if ( curve.hasCurvedSegments() )
      polylineFlags.setFlag( QgsDxfExport::DxfPolylineFlag::Curve );
 
    // Might need to conditional once this feature is implemented
    //   https://github.com/qgis/QGIS/issues/32468
    polylineFlags.setFlag( QgsDxfExport::DxfPolylineFlag::ContinuousPattern );
 
    writeGroup( 70, static_cast<int>( polylineFlags ) );
    writeGroup( 43, width );
 
    for ( int i = 0; i < points.size(); i++ )
    {
      writeGroup( 0, points[i] );
      if ( bulges[i] != 0.0 )
        writeGroup( 42, bulges[i] );
    }
  }
  else
  {
    writeGroup( 0, u"POLYLINE"_s );
    int plHandle = writeHandle();
    writeGroup( 330, mBlockHandle );
    writeGroup( 100, u"AcDbEntity"_s );
    writeGroup( 8, layer );
    writeGroup( 6, lineStyleName );
    writeGroup( color );
    writeGroup( 100, u"AcDb3dPolyline"_s );
    writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 0.0 ) );
    writeGroup( 70, 8 );
 
    for ( int i = 0; i < points.size(); i++ )
    {
      writeGroup( 0, u"VERTEX"_s );
      writeHandle();
      writeGroup( 330, plHandle );
      writeGroup( 100, u"AcDbEntity"_s );
      writeGroup( 8, layer );
      writeGroup( color );
      writeGroup( 100, u"AcDbVertex"_s );
      writeGroup( 100, u"AcDb3dPolylineVertex"_s );
      writeGroup( 0, points[i] );
      if ( bulges[i] != 0.0 )
        writeGroup( 42, bulges[i] );
      writeGroup( 70, 32 );
    }
 
    writeGroup( 0, u"SEQEND"_s );
    writeHandle();
    writeGroup( 330, plHandle );
    writeGroup( 100, u"AcDbEntity"_s );
    writeGroup( 8, layer );
    writeGroup( color );
  }
}
 
void QgsDxfExport::writePolygon( const QgsRingSequence &polygon, const QString &layer, const QString &hatchPattern, const QColor &color )
{
  writeGroup( 0, u"HATCH"_s ); // Entity type
  writeHandle();
  writeGroup( 330, mBlockHandle );
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 8, layer ); // Layer name
  writeGroup( color );    // Color
  writeGroup( 100, u"AcDbHatch"_s );
 
  writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 0.0 ) ); // Elevation point (in OCS)
  writeGroup( 200, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 1.0 ) );
 
  writeGroup( 2, hatchPattern );                // Hatch pattern name
  writeGroup( 70, hatchPattern == "SOLID"_L1 ); // Solid fill flag (solid fill = 1; pattern fill = 0)
  writeGroup( 71, 0 );                          // Associativity flag (associative = 1; non-associative = 0)
 
  writeGroup( 91, polygon.size() ); // Number of boundary paths (loops)
  for ( int i = 0; i < polygon.size(); ++i )
  {
    writeGroup( 92, 2 );                 // Boundary path type flag (bit coded): 0 = Default; 1 = External; 2 = Polyline 4 = Derived; 8 = Textbox; 16 = Outermost
    writeGroup( 72, 0 );                 // Has bulge flag
    writeGroup( 73, 1 );                 // Is closed flag
    writeGroup( 93, polygon[i].size() ); // Number of edges in this boundary path (only if boundary is not a polyline)
 
    for ( int j = 0; j < polygon[i].size(); ++j )
    {
      writeGroup( 0, polygon[i][j] ); // Vertex location (in OCS)
    }
 
    writeGroup( 97, 0 ); // Number of source boundary objects
  }
 
  writeGroup( 75, 0 ); // Hatch style: 0 = Hatch "odd parity" area (Normal style), 1 = Hatch outermost area only (Outer style), 2 = Hatch through entire area (Ignore style)
  writeGroup( 76, 1 ); // Hatch pattern type: 0 = User-defined; 1 = Predefined; 2 = Custom
 
  writeGroup( 98, 0 ); // Number of seed points
}
 
void QgsDxfExport::writePolygon( const QgsCurvePolygon &polygon, const QString &layer, const QString &hatchPattern, const QColor &color )
{
  writeGroup( 0, u"HATCH"_s ); // Entity type
  writeHandle();
  writeGroup( 330, mBlockHandle );
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 8, layer ); // Layer name
  writeGroup( color );    // Color
  writeGroup( 100, u"AcDbHatch"_s );
 
  writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 0.0 ) ); // Elevation point (in OCS)
  writeGroup( 200, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 1.0 ) );
 
  writeGroup( 2, hatchPattern );                // Hatch pattern name
  writeGroup( 70, hatchPattern == "SOLID"_L1 ); // Solid fill flag (solid fill = 1; pattern fill = 0)
  writeGroup( 71, 0 );                          // Associativity flag (associative = 1; non-associative = 0)
 
  QVector<QVector<QgsPoint>> points;
  QVector<QVector<double>> bulges;
 
  const int ringCount = polygon.numInteriorRings();
  points.reserve( ringCount + 1 );
  bulges.reserve( ringCount + 1 );
 
  points << QVector<QgsPoint>();
  bulges << QVector<double>();
  appendCurve( *polygon.exteriorRing(), points.last(), bulges.last() );
 
  for ( int i = 0; i < ringCount; i++ )
  {
    points << QVector<QgsPoint>();
    bulges << QVector<double>();
    appendCurve( *polygon.interiorRing( i ), points.last(), bulges.last() );
  }
 
  bool hasBulges = false;
  for ( int i = 0; i < points.size() && !hasBulges; ++i )
    for ( int j = 0; j < points[i].size() && !hasBulges; ++j )
      hasBulges = bulges[i][j] != 0.0;
 
  writeGroup( 91, points.size() ); // Number of boundary paths (loops)
 
  for ( int i = 0; i < points.size(); ++i )
  {
    writeGroup( 92, 2 );                 // Boundary path type flag (bit coded): 0 = Default; 1 = External; 2 = Polyline 4 = Derived; 8 = Textbox; 16 = Outermost
    writeGroup( 72, hasBulges ? 1 : 0 ); // Has bulge flag
    writeGroup( 73, 1 );                 // Is closed flag
    writeGroup( 93, points[i].size() );  // Number of edges in this boundary path (only if boundary is not a polyline)
 
    for ( int j = 0; j < points[i].size(); ++j )
    {
      writeGroup( 0, points[i][j] ); // Vertex location (in OCS)
      if ( hasBulges )
        writeGroup( 42, bulges[i][j] );
    }
 
    writeGroup( 97, 0 ); // Number of source boundary objects
  }
 
  writeGroup( 75, 0 ); // Hatch style: 0 = Hatch "odd parity" area (Normal style), 1 = Hatch outermost area only (Outer style), 2 = Hatch through entire area (Ignore style)
  writeGroup( 76, 1 ); // Hatch pattern type: 0 = User-defined; 1 = Predefined; 2 = Custom
 
  writeGroup( 98, 0 ); // Number of seed points
}
 
void QgsDxfExport::writeLine( const QgsPoint &pt1, const QgsPoint &pt2, const QString &layer, const QString &lineStyleName, const QColor &color, double width )
{
  writePolyline( QgsPointSequence() << pt1 << pt2, layer, lineStyleName, color, width );
}
 
void QgsDxfExport::writeText( const QString &layer, const QString &text, pal::LabelPosition *label, const QgsPalLayerSettings &layerSettings, const QgsExpressionContext &expressionContext )
{
  double lblX = label->getX();
  double lblY = label->getY();
 
  QgsLabelFeature *labelFeature = label->getFeaturePart()->feature();
 
  HAlign hali = HAlign::Undefined;
  VAlign vali = VAlign::Undefined;
 
  const QgsPropertyCollection &props = layerSettings.dataDefinedProperties();
 
  if ( layerSettings.placement == Qgis::LabelPlacement::OverPoint )
  {
    lblX = labelFeature->anchorPosition().x();
    lblY = labelFeature->anchorPosition().y();
 
    Qgis::LabelQuadrantPosition offsetQuad = layerSettings.pointSettings().quadrant();
 
    if ( props.isActive( QgsPalLayerSettings::Property::OffsetQuad ) )
    {
      const QVariant exprVal = props.value( QgsPalLayerSettings::Property::OffsetQuad, expressionContext );
      if ( !QgsVariantUtils::isNull( exprVal ) )
      {
        offsetQuad = static_cast<Qgis::LabelQuadrantPosition>( exprVal.toInt() );
      }
    }
 
    switch ( offsetQuad )
    {
      case Qgis::LabelQuadrantPosition::AboveLeft:
        hali = HAlign::HRight;
        vali = VAlign::VBottom;
        break;
      case Qgis::LabelQuadrantPosition::Above:
        hali = HAlign::HCenter;
        vali = VAlign::VBottom;
        break;
      case Qgis::LabelQuadrantPosition::AboveRight:
        hali = HAlign::HLeft;
        vali = VAlign::VBottom;
        break;
      case Qgis::LabelQuadrantPosition::Left:
        hali = HAlign::HRight;
        vali = VAlign::VMiddle;
        break;
      case Qgis::LabelQuadrantPosition::Over:
        hali = HAlign::HCenter;
        vali = VAlign::VMiddle;
        break;
      case Qgis::LabelQuadrantPosition::Right:
        hali = HAlign::HLeft;
        vali = VAlign::VMiddle;
        break;
      case Qgis::LabelQuadrantPosition::BelowLeft:
        hali = HAlign::HRight;
        vali = VAlign::VTop;
        break;
      case Qgis::LabelQuadrantPosition::Below:
        hali = HAlign::HCenter;
        vali = VAlign::VTop;
        break;
      case Qgis::LabelQuadrantPosition::BelowRight:
        hali = HAlign::HLeft;
        vali = VAlign::VTop;
        break;
    }
  }
 
  if ( props.isActive( QgsPalLayerSettings::Property::Hali ) )
  {
    lblX = labelFeature->anchorPosition().x();
    lblY = labelFeature->anchorPosition().y();
 
    hali = HAlign::HLeft;
    QVariant exprVal = props.value( QgsPalLayerSettings::Property::Hali, expressionContext );
    if ( !QgsVariantUtils::isNull( exprVal ) )
    {
      const QString haliString = exprVal.toString();
      if ( haliString.compare( "Center"_L1, Qt::CaseInsensitive ) == 0 )
      {
        hali = HAlign::HCenter;
      }
      else if ( haliString.compare( "Right"_L1, Qt::CaseInsensitive ) == 0 )
      {
        hali = HAlign::HRight;
      }
    }
  }
 
  //vertical alignment
  if ( props.isActive( QgsPalLayerSettings::Property::Vali ) )
  {
    vali = VAlign::VBottom;
    QVariant exprVal = props.value( QgsPalLayerSettings::Property::Vali, expressionContext );
    if ( !QgsVariantUtils::isNull( exprVal ) )
    {
      const QString valiString = exprVal.toString();
      if ( valiString.compare( "Bottom"_L1, Qt::CaseInsensitive ) != 0 )
      {
        if ( valiString.compare( "Base"_L1, Qt::CaseInsensitive ) == 0 )
        {
          vali = VAlign::VBaseLine;
        }
        else if ( valiString.compare( "Half"_L1, Qt::CaseInsensitive ) == 0 )
        {
          vali = VAlign::VMiddle;
        }
        else //'Cap' or 'Top'
        {
          vali = VAlign::VTop;
        }
      }
    }
  }
 
  writeText( layer, text, QgsPoint( lblX, lblY ), label->getHeight(), label->getAlpha() * 180.0 / M_PI, layerSettings.format().color(), hali, vali );
}
 
void QgsDxfExport::writePoint( const QString &layer, const QColor &color, const QgsPoint &pt )
{
  writeGroup( 0, u"POINT"_s );
  writeHandle();
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 100, u"AcDbPoint"_s );
  writeGroup( 8, layer );
  writeGroup( color );
  writeGroup( 0, pt );
}
 
void QgsDxfExport::writeFilledCircle( const QString &layer, const QColor &color, const QgsPoint &pt, double radius )
{
  writeGroup( 0, u"HATCH"_s ); // Entity type
  writeHandle();
  writeGroup( 330, mBlockHandle );
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 8, layer ); // Layer name
  writeGroup( color );    // Color (0 by block, 256 by layer)
  writeGroup( 100, u"AcDbHatch"_s );
 
  writeGroup( 0, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 0.0 ) ); // Elevation point (in OCS)
  writeGroup( 200, QgsPoint( Qgis::WkbType::PointZ, 0.0, 0.0, 1.0 ) );
 
  writeGroup( 2, u"SOLID"_s ); // Hatch pattern name
  writeGroup( 70, 1 );         // Solid fill flag (solid fill = 1; pattern fill = 0)
  writeGroup( 71, 0 );         // Associativity flag (associative = 1; non-associative = 0)
 
  writeGroup( 91, 1 ); // Number of boundary paths (loops)
 
  writeGroup( 92, 3 ); // Boundary path type flag (bit coded): 0 = Default; 1 = External; 2 = Polyline 4 = Derived; 8 = Textbox; 16 = Outermost
  writeGroup( 72, 1 );
  writeGroup( 73, 1 ); // Is closed flag
  writeGroup( 93, 2 ); // Number of polyline vertices
 
  writeGroup( 0, QgsPoint( Qgis::WkbType::Point, pt.x() - radius, pt.y() ) );
  writeGroup( 42, 1.0 );
 
  writeGroup( 0, QgsPoint( Qgis::WkbType::Point, pt.x() + radius, pt.y() ) );
  writeGroup( 42, 1.0 );
 
  writeGroup( 97, 0 ); // Number of source boundary objects
 
  writeGroup( 75, 0 ); // Hatch style: 0 = Hatch "odd parity" area (Normal style), 1 = Hatch outermost area only (Outer style), 2 = Hatch through entire area (Ignore style)
  writeGroup( 76, 1 ); // Hatch pattern type: 0 = User-defined; 1 = Predefined; 2 = Custom
  writeGroup( 98, 0 ); // Number of seed points
}
 
void QgsDxfExport::writeCircle( const QString &layer, const QColor &color, const QgsPoint &pt, double radius, const QString &lineStyleName, double width )
{
  writeGroup( 0, u"LWPOLYLINE"_s );
  writeHandle();
  writeGroup( 330, mBlockHandle );
  writeGroup( 8, layer );
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 100, u"AcDbPolyline"_s );
  writeGroup( 6, lineStyleName );
  writeGroup( color );
 
  writeGroup( 90, 2 );
 
  writeGroup( 70, 1 );
  writeGroup( 43, width );
 
  writeGroup( 0, QgsPoint( pt.x() - radius, pt.y() ) );
  writeGroup( 42, 1.0 );
  writeGroup( 0, QgsPoint( pt.x() + radius, pt.y() ) );
  writeGroup( 42, 1.0 );
}
 
void QgsDxfExport::writeText( const QString &layer, const QString &text, const QgsPoint &pt, double size, double angle, const QColor &color, HAlign hali, VAlign vali )
{
  writeGroup( 0, u"TEXT"_s );
  writeHandle();
  writeGroup( 100, u"AcDbEntity"_s );
  // writeGroup( 6, "Continuous" ); // Line style
  // writeGroup( 370, 18 ); // Line weight
  writeGroup( 100, u"AcDbText"_s );
  writeGroup( 8, layer );
  writeGroup( color );
  writeGroup( 0, pt );
  if ( hali != HAlign::Undefined || vali != VAlign::Undefined )
    writeGroup( 1, pt ); // Second alignment point
  writeGroup( 40, size );
  writeGroup( 1, text );
  writeGroup( 50, fmod( angle, 360 ) );
  if ( hali != HAlign::Undefined )
    writeGroup( 72, static_cast<int>( hali ) );
  writeGroup( 7, u"STANDARD"_s ); // so far only support for standard font
  writeGroup( 100, u"AcDbText"_s );
  if ( vali != VAlign::Undefined )
  {
    writeGroup( 73, static_cast<int>( vali ) );
  }
}
 
void QgsDxfExport::writeMText( const QString &layer, const QString &text, const QgsPoint &pt, double width, double angle, const QColor &color )
{
  writeGroup( 0, u"MTEXT"_s );
  writeHandle();
  writeGroup( 100, u"AcDbEntity"_s );
  writeGroup( 100, u"AcDbMText"_s );
  writeGroup( 8, layer );
  writeGroup( color );
 
  writeGroup( 0, pt );
 
  QString t( text );
  while ( t.length() > 250 )
  {
    writeGroup( 3, t.left( 250 ) );
    t = t.mid( 250 );
  }
  writeGroup( 1, t );
 
  writeGroup( 50, angle );       // Rotation angle in radians
  writeGroup( 41, width * 1.1 ); // Reference rectangle width
 
  // Attachment point:
  // 1 2 3
  // 4 5 6
  // 7 8 9
  writeGroup( 71, 7 );
 
  writeGroup( 7, u"STANDARD"_s ); // so far only support for standard font
}
 
void QgsDxfExport::addFeature( QgsSymbolRenderContext &ctx, const QgsCoordinateTransform &ct, const QString &layer, const QgsSymbolLayer *symbolLayer, const QgsSymbol *symbol )
{
  const QgsFeature *fet = ctx.feature();
  if ( !fet )
    return;
 
  if ( !fet->hasGeometry() )
    return;
 
  QgsGeometry geom( fet->geometry() );
  if ( ct.isValid() )
  {
    geom.transform( ct );
  }
 
  Qgis::WkbType geometryType = geom.wkbType();
 
  QColor penColor;
  QColor brushColor;
  if ( mSymbologyExport != Qgis::FeatureSymbologyExport::NoSymbology && symbolLayer )
  {
    penColor = colorFromSymbolLayer( symbolLayer, ctx );
    brushColor = symbolLayer->dxfBrushColor( ctx );
  }
 
  Qt::PenStyle penStyle( Qt::SolidLine );
  Qt::BrushStyle brushStyle( Qt::NoBrush );
  double width = -1;
  double offset = 0.0;
  double angle = 0.0;
  if ( mSymbologyExport != Qgis::FeatureSymbologyExport::NoSymbology && symbolLayer )
  {
    width = symbolLayer->dxfWidth( ctx );
    offset = symbolLayer->dxfOffset( ctx );
    angle = symbolLayer->dxfAngle( ctx );
    penStyle = symbolLayer->dxfPenStyle();
    brushStyle = symbolLayer->dxfBrushStyle();
 
    if ( qgsDoubleNear( offset, 0.0 ) )
      offset = 0.0;
  }
 
  if ( mFlags & FlagHairlineWidthExport )
  {
    width = 0;
  }
 
  QString lineStyleName = u"CONTINUOUS"_s;
  if ( mSymbologyExport != Qgis::FeatureSymbologyExport::NoSymbology )
  {
    lineStyleName = lineStyleFromSymbolLayer( symbolLayer );
  }
 
  // single point
  if ( QgsWkbTypes::flatType( geometryType ) == Qgis::WkbType::Point )
  {
    writePoint( geom.constGet()->coordinateSequence().at( 0 ).at( 0 ).at( 0 ), layer, penColor, ctx, symbolLayer, symbol, angle );
    return;
  }
 
  if ( QgsWkbTypes::flatType( geometryType ) == Qgis::WkbType::MultiPoint )
  {
    const QgsCoordinateSequence &cs = geom.constGet()->coordinateSequence();
    for ( int i = 0; i < cs.size(); i++ )
    {
      writePoint( cs.at( i ).at( 0 ).at( 0 ), layer, penColor, ctx, symbolLayer, symbol, angle );
    }
    return;
  }
 
  if ( penStyle != Qt::NoPen )
  {
    const QgsAbstractGeometry *sourceGeom = geom.constGet();
    std::unique_ptr< QgsAbstractGeometry > tempGeom;
 
    switch ( QgsWkbTypes::flatType( geometryType ) )
    {
      case Qgis::WkbType::CircularString:
      case Qgis::WkbType::CompoundCurve:
      case Qgis::WkbType::LineString:
      case Qgis::WkbType::MultiCurve:
      case Qgis::WkbType::MultiLineString:
      {
        if ( !qgsDoubleNear( offset, 0.0 ) )
        {
          QgsGeos geos( sourceGeom );
          tempGeom.reset( geos.offsetCurve( offset, 0, Qgis::JoinStyle::Miter, 2.0 ) ); //#spellok
          if ( tempGeom )
            sourceGeom = tempGeom.get();
          else
            sourceGeom = geom.constGet();
        }
 
        const QgsCurve *curve = dynamic_cast<const QgsCurve *>( sourceGeom );
        if ( curve )
        {
          writePolyline( *curve, layer, lineStyleName, penColor, width );
        }
        else
        {
          const QgsGeometryCollection *gc = dynamic_cast<const QgsGeometryCollection *>( sourceGeom );
          Q_ASSERT( gc );
          if ( gc )
          {
            for ( int i = 0; i < gc->numGeometries(); i++ )
            {
              const QgsCurve *curve = dynamic_cast<const QgsCurve *>( gc->geometryN( i ) );
              Q_ASSERT( curve );
              writePolyline( *curve, layer, lineStyleName, penColor, width );
            }
          }
        }
        break;
      }
 
      case Qgis::WkbType::CurvePolygon:
      case Qgis::WkbType::Polygon:
      case Qgis::WkbType::MultiSurface:
      case Qgis::WkbType::MultiPolygon:
      {
        if ( !qgsDoubleNear( offset, 0.0 ) )
        {
          QgsGeos geos( sourceGeom );
          tempGeom.reset( geos.buffer( offset, 0, Qgis::EndCapStyle::Flat, Qgis::JoinStyle::Miter, 2.0 ) ); //#spellok
          if ( tempGeom )
            sourceGeom = tempGeom.get();
          else
            sourceGeom = geom.constGet();
        }
 
        const QgsCurvePolygon *polygon = dynamic_cast<const QgsCurvePolygon *>( sourceGeom );
        if ( polygon )
        {
          writePolyline( *polygon->exteriorRing(), layer, lineStyleName, penColor, width );
          for ( int i = 0; i < polygon->numInteriorRings(); i++ )
            writePolyline( *polygon->interiorRing( i ), layer, lineStyleName, penColor, width );
        }
        else
        {
          const QgsGeometryCollection *gc = dynamic_cast<const QgsGeometryCollection *>( sourceGeom );
          Q_ASSERT( gc );
          if ( gc )
          {
            for ( int i = 0; i < gc->numGeometries(); i++ )
            {
              const QgsCurvePolygon *polygon = dynamic_cast<const QgsCurvePolygon *>( gc->geometryN( i ) );
              Q_ASSERT( polygon );
 
              writePolyline( *polygon->exteriorRing(), layer, lineStyleName, penColor, width );
              for ( int j = 0; j < polygon->numInteriorRings(); j++ )
                writePolyline( *polygon->interiorRing( j ), layer, lineStyleName, penColor, width );
            }
          }
        }
 
        break;
      }
 
      default:
        break;
    }
  }
 
  if ( brushStyle != Qt::NoBrush )
  {
    const QgsAbstractGeometry *sourceGeom = geom.constGet();
 
    switch ( QgsWkbTypes::flatType( geometryType ) )
    {
      case Qgis::WkbType::CurvePolygon:
      case Qgis::WkbType::Polygon:
      {
        const QgsCurvePolygon *polygon = dynamic_cast<const QgsCurvePolygon *>( sourceGeom );
        Q_ASSERT( polygon );
        writePolygon( *polygon, layer, u"SOLID"_s, brushColor );
        break;
      }
 
      case Qgis::WkbType::MultiSurface:
      case Qgis::WkbType::MultiPolygon:
      {
        const QgsGeometryCollection *gc = dynamic_cast<const QgsGeometryCollection *>( sourceGeom );
        Q_ASSERT( gc );
 
        for ( int i = 0; i < gc->numGeometries(); i++ )
        {
          const QgsCurvePolygon *polygon = dynamic_cast<const QgsCurvePolygon *>( gc->geometryN( i ) );
          Q_ASSERT( polygon );
          writePolygon( *polygon, layer, u"SOLID"_s, brushColor );
        }
        break;
      }
 
      default:
        break;
    }
  }
}
 
QColor QgsDxfExport::colorFromSymbolLayer( const QgsSymbolLayer *symbolLayer, QgsSymbolRenderContext &ctx )
{
  if ( !symbolLayer )
    return QColor();
 
  return symbolLayer->dxfColor( ctx );
}
 
QString QgsDxfExport::lineStyleFromSymbolLayer( const QgsSymbolLayer *symbolLayer )
{
  QString lineStyleName = u"CONTINUOUS"_s;
  if ( !symbolLayer )
  {
    return lineStyleName;
  }
 
  QHash< const QgsSymbolLayer *, QString >::const_iterator lineTypeIt = mLineStyles.constFind( symbolLayer );
  if ( lineTypeIt != mLineStyles.constEnd() )
  {
    lineStyleName = lineTypeIt.value();
    return lineStyleName;
  }
  else
  {
    return lineNameFromPenStyle( symbolLayer->dxfPenStyle() );
  }
}
 
int QgsDxfExport::closestColorMatch( QRgb pixel )
{
  int idx = 0;
  int current_distance = std::numeric_limits<int>::max();
  for ( int i = 1; i < static_cast< int >( sizeof( sDxfColors ) / sizeof( *sDxfColors ) ); ++i )
  {
    int dist = color_distance( pixel, i );
    if ( dist < current_distance )
    {
      current_distance = dist;
      idx = i;
      if ( dist == 0 )
        break;
    }
  }
  return idx;
}
 
int QgsDxfExport::color_distance( QRgb p1, int index )
{
  if ( index > 255 || index < 0 )
  {
    return 0;
  }
 
  double redDiff = qRed( p1 ) - sDxfColors[index][0];
  double greenDiff = qGreen( p1 ) - sDxfColors[index][1];
  double blueDiff = qBlue( p1 ) - sDxfColors[index][2];
#if 0
  QgsDebugMsgLevel( u"color_distance( r:%1 g:%2 b:%3 <=> i:%4 r:%5 g:%6 b:%7 ) => %8"_s
                    .arg( qRed( p1 ) ).arg( qGreen( p1 ) ).arg( qBlue( p1 ) )
                    .arg( index )
                    .arg( mDxfColors[index][0] )
                    .arg( mDxfColors[index][1] )
                    .arg( mDxfColors[index][2] )
                    .arg( redDiff * redDiff + greenDiff * greenDiff + blueDiff * blueDiff ), 2 );
#endif
  return redDiff * redDiff + greenDiff * greenDiff + blueDiff * blueDiff;
}
 
QRgb QgsDxfExport::createRgbEntry( qreal r, qreal g, qreal b )
{
  return QColor::fromRgbF( r, g, b ).rgb();
}
 
QgsRenderContext QgsDxfExport::renderContext() const
{
  return mRenderContext;
}
 
double QgsDxfExport::mapUnitScaleFactor( double scale, Qgis::RenderUnit symbolUnits, Qgis::DistanceUnit mapUnits, double mapUnitsPerPixel )
{
  switch ( symbolUnits )
  {
    case Qgis::RenderUnit::MapUnits:
      return 1.0;
 
    case Qgis::RenderUnit::Millimeters:
      return ( scale * QgsUnitTypes::fromUnitToUnitFactor( Qgis::DistanceUnit::Meters, mapUnits ) / 1000.0 );
 
    case Qgis::RenderUnit::Points:
      // 1 pt = 25.4/72 mm
      return ( scale * QgsUnitTypes::fromUnitToUnitFactor( Qgis::DistanceUnit::Meters, mapUnits ) / 1000.0 * 25.4 / 72.0 );
 
    case Qgis::RenderUnit::Inches:
      return ( scale * QgsUnitTypes::fromUnitToUnitFactor( Qgis::DistanceUnit::Meters, mapUnits ) / 1000.0 * 25.4 );
 
    case Qgis::RenderUnit::MetersInMapUnits:
      return QgsUnitTypes::fromUnitToUnitFactor( Qgis::DistanceUnit::Meters, mapUnits );
 
    case Qgis::RenderUnit::Pixels:
      return mapUnitsPerPixel;
 
    case Qgis::RenderUnit::Unknown:
    case Qgis::RenderUnit::Percentage:
      break;
  }
  return 1.0;
}
 
double QgsDxfExport::mapUnitScaleFactor( const QgsRenderContext &renderContext, Qgis::RenderUnit symbolUnits )
{
  return renderContext.convertToMapUnits( 1.0, symbolUnits );
}
 
void QgsDxfExport::clipValueToMapUnitScale( double &value, const QgsMapUnitScale &scale, double pixelToMMFactor ) const
{
  if ( !scale.minSizeMMEnabled && !scale.maxSizeMMEnabled )
  {
    return;
  }
 
  double mapUnitsPerPixel = mMapSettings.mapToPixel().mapUnitsPerPixel();
 
  double minSizeMU = std::numeric_limits<double>::lowest();
  if ( scale.minSizeMMEnabled )
  {
    minSizeMU = scale.minSizeMM * pixelToMMFactor * mapUnitsPerPixel;
  }
  if ( !qgsDoubleNear( scale.minScale, 0.0 ) )
  {
    minSizeMU = std::max( minSizeMU, value );
  }
  value = std::max( value, minSizeMU );
 
  double maxSizeMU = std::numeric_limits<double>::max();
  if ( scale.maxSizeMMEnabled )
  {
    maxSizeMU = scale.maxSizeMM * pixelToMMFactor * mapUnitsPerPixel;
  }
  if ( !qgsDoubleNear( scale.maxScale, 0.0 ) )
  {
    maxSizeMU = std::min( maxSizeMU, value );
  }
  value = std::min( value, maxSizeMU );
}
 
QList< QPair< QgsSymbolLayer *, QgsSymbol * > > QgsDxfExport::symbolLayers( QgsRenderContext &context )
{
  QList< QPair< QgsSymbolLayer *, QgsSymbol * > > symbolLayers;
 
  for ( DxfLayerJob *job : std::as_const( mJobs ) )
  {
    const QgsSymbolList symbols = job->renderer->symbols( context );
 
    for ( QgsSymbol *symbol : symbols )
    {
      int maxSymbolLayers = symbol->symbolLayerCount();
      if ( mSymbologyExport != Qgis::FeatureSymbologyExport::PerSymbolLayer )
      {
        maxSymbolLayers = 1;
      }
      for ( int i = 0; i < maxSymbolLayers; ++i )
      {
        symbolLayers.append( qMakePair( symbol->symbolLayer( i ), symbol ) );
      }
    }
  }
 
  return symbolLayers;
}
 
void QgsDxfExport::writeDefaultLinetypes()
{
  // continuous (Qt solid line)
  for ( const QString &ltype : { u"ByLayer"_s, u"ByBlock"_s, u"CONTINUOUS"_s } )
  {
    writeGroup( 0, u"LTYPE"_s );
    writeHandle();
    writeGroup( 100, u"AcDbSymbolTableRecord"_s );
    writeGroup( 100, u"AcDbLinetypeTableRecord"_s );
    writeGroup( 2, ltype );
    writeGroup( 70, 64 );
    writeGroup( 3, u"Defaultstyle"_s );
    writeGroup( 72, 65 );
    writeGroup( 73, 0 );
    writeGroup( 40, 0.0 );
  }
 
  double das = dashSize();
  double dss = dashSeparatorSize();
  double dos = dotSize();
 
  QVector<qreal> dashVector( 2 );
  dashVector[0] = das;
  dashVector[1] = dss;
  writeLinetype( u"DASH"_s, dashVector, Qgis::RenderUnit::MapUnits );
 
  QVector<qreal> dotVector( 2 );
  dotVector[0] = dos;
  dotVector[1] = dss;
  writeLinetype( u"DOT"_s, dotVector, Qgis::RenderUnit::MapUnits );
 
  QVector<qreal> dashDotVector( 4 );
  dashDotVector[0] = das;
  dashDotVector[1] = dss;
  dashDotVector[2] = dos;
  dashDotVector[3] = dss;
  writeLinetype( u"DASHDOT"_s, dashDotVector, Qgis::RenderUnit::MapUnits );
 
  QVector<qreal> dashDotDotVector( 6 );
  dashDotDotVector[0] = das;
  dashDotDotVector[1] = dss;
  dashDotDotVector[2] = dos;
  dashDotDotVector[3] = dss;
  dashDotDotVector[4] = dos;
  dashDotDotVector[5] = dss;
  writeLinetype( u"DASHDOTDOT"_s, dashDotDotVector, Qgis::RenderUnit::MapUnits );
}
 
void QgsDxfExport::writeSymbolLayerLinetype( const QgsSymbolLayer *symbolLayer )
{
  if ( !symbolLayer )
  {
    return;
  }
 
  Qgis::RenderUnit unit;
  QVector<qreal> customLinestyle = symbolLayer->dxfCustomDashPattern( unit );
  if ( !customLinestyle.isEmpty() )
  {
    QString name = u"symbolLayer%1"_s.arg( mSymbolLayerCounter++ );
    writeLinetype( name, customLinestyle, unit );
    mLineStyles.insert( symbolLayer, name );
  }
}
 
int QgsDxfExport::nLineTypes( const QList< QPair< QgsSymbolLayer *, QgsSymbol * > > &symbolLayers )
{
  int nLineTypes = 0;
  for ( const auto &symbolLayer : symbolLayers )
  {
    const QgsSimpleLineSymbolLayer *simpleLine = dynamic_cast< const QgsSimpleLineSymbolLayer * >( symbolLayer.first );
    if ( simpleLine )
    {
      if ( simpleLine->useCustomDashPattern() )
      {
        ++nLineTypes;
      }
    }
  }
  return nLineTypes;
}
 
void QgsDxfExport::writeLinetype( const QString &styleName, const QVector<qreal> &pattern, Qgis::RenderUnit u )
{
  double length = 0;
  for ( qreal size : pattern )
  {
    length += ( size * mapUnitScaleFactor( mRenderContext, u ) );
  }
 
  writeGroup( 0, u"LTYPE"_s );
  writeHandle();
  // 330 5
  writeGroup( 100, u"AcDbSymbolTableRecord"_s );
  writeGroup( 100, u"AcDbLinetypeTableRecord"_s );
  writeGroup( 2, styleName );
  writeGroup( 70, 64 ); // 0?
  writeGroup( 3, QString() );
  writeGroup( 72, 65 );
  writeGroup( 73, pattern.size() );
  writeGroup( 40, length );
 
  bool isGap = false;
  for ( qreal size : pattern )
  {
    // map units or mm?
    double segmentLength = ( isGap ? -size : size );
    segmentLength *= mapUnitScaleFactor( mRenderContext, u );
    writeGroup( 49, segmentLength );
    writeGroup( 74, 0 );
    isGap = !isGap;
  }
}
 
void QgsDxfExport::addGeometryGeneratorSymbolLayer( QgsSymbolRenderContext &ctx, const QgsCoordinateTransform &ct, const QString &layer, QgsSymbolLayer *symbolLayer, bool allSymbolLayers )
{
  QgsGeometryGeneratorSymbolLayer *gg = dynamic_cast<QgsGeometryGeneratorSymbolLayer *>( symbolLayer );
  if ( !gg )
  {
    return;
  }
 
  const QgsFeature *fet = ctx.feature();
  if ( !fet )
  {
    return;
  }
 
  QgsFeature f = *fet;
 
  QgsExpressionContext &expressionContext = ctx.renderContext().expressionContext();
  QgsExpression geomExpr( gg->geometryExpression() );
  geomExpr.prepare( &expressionContext );
  QgsGeometry geom = geomExpr.evaluate( &expressionContext ).value<QgsGeometry>();
  f.setGeometry( geom );
 
  QgsSymbol *symbol = gg->subSymbol();
  if ( symbol && symbol->symbolLayerCount() > 0 )
  {
    QgsExpressionContextScope *symbolExpressionContextScope = symbol->symbolRenderContext()->expressionContextScope();
    symbolExpressionContextScope->setFeature( f );
 
    ctx.setFeature( &f );
 
    int nSymbolLayers = allSymbolLayers ? symbol->symbolLayerCount() : 1;
    for ( int i = 0; i < nSymbolLayers; ++i )
    {
      addFeature( ctx, ct, layer, symbol->symbolLayer( i ), symbol );
    }
 
    ctx.setFeature( fet );
  }
}
 
bool QgsDxfExport::hasBlockBreakingDataDefinedProperties( const QgsSymbolLayer *sl, const QgsSymbol *symbol )
{
  if ( !sl || !symbol )
  {
    return false;
  }
 
  bool blockBreak = false;
  if ( sl->hasDataDefinedProperties() )
  {
    QSet<int> properties = sl->dataDefinedProperties().propertyKeys();
    // Remove data defined properties handled through DXF property codes
    properties.remove( static_cast< int >( QgsSymbolLayer::Property::Size ) );
    properties.remove( static_cast< int >( QgsSymbolLayer::Property::Angle ) );
    blockBreak = !properties.isEmpty();
  }
 
  return blockBreak;
}
 
bool QgsDxfExport::isSymbolLayerEnabled( const QgsSymbolLayer *layer, QgsSymbolRenderContext &context )
{
  if ( !layer || !layer->enabled() )
    return false;
  if ( layer->dataDefinedProperties().hasActiveProperties() && !layer->dataDefinedProperties().valueAsBool( QgsSymbolLayer::Property::LayerEnabled, context.renderContext().expressionContext(), true ) )
    return false;
  return true;
}
 
double QgsDxfExport::dashSize() const
{
  double size = mSymbologyScale * 0.002;
  return sizeToMapUnits( size );
}
 
double QgsDxfExport::dotSize() const
{
  double size = mSymbologyScale * 0.0006;
  return sizeToMapUnits( size );
}
 
double QgsDxfExport::dashSeparatorSize() const
{
  double size = mSymbologyScale * 0.0006;
  return sizeToMapUnits( size );
}
 
double QgsDxfExport::sizeToMapUnits( double s ) const
{
  double size = s * QgsUnitTypes::fromUnitToUnitFactor( Qgis::DistanceUnit::Meters, mMapUnits );
  return size;
}
 
QString QgsDxfExport::lineNameFromPenStyle( Qt::PenStyle style )
{
  switch ( style )
  {
    case Qt::DashLine:
      return u"DASH"_s;
    case Qt::DotLine:
      return u"DOT"_s;
    case Qt::DashDotLine:
      return u"DASHDOT"_s;
    case Qt::DashDotDotLine:
      return u"DASHDOTDOT"_s;
    case Qt::SolidLine:
    default:
      return u"CONTINUOUS"_s;
  }
}
 
QString QgsDxfExport::dxfLayerName( const QString &name )
{
  if ( name.isEmpty() )
    return u"0"_s;
 
  // dxf layers can be max 255 characters long
  QString layerName = name.left( 255 );
 
  // replaced restricted characters with underscore
  // < > / \ " : ; ? * | = '
  // See http://docs.autodesk.com/ACD/2010/ENU/AutoCAD%202010%20User%20Documentation/index.html?url=WS1a9193826455f5ffa23ce210c4a30acaf-7345.htm,topicNumber=d0e41665
  layerName.replace( '<', '_' );
  layerName.replace( '>', '_' );
  layerName.replace( '/', '_' );
  layerName.replace( '\\', '_' );
  layerName.replace( '\"', '_' );
  layerName.replace( ':', '_' );
  layerName.replace( ';', '_' );
  layerName.replace( '?', '_' );
  layerName.replace( '*', '_' );
  layerName.replace( '|', '_' );
  layerName.replace( '=', '_' );
  layerName.replace( '\'', '_' );
  // if layer name contains comma, resulting file is unreadable in AutoCAD
  // see https://github.com/qgis/QGIS/issues/47381
  layerName.replace( ',', '_' );
 
  // also remove newline characters (#15067)
  layerName.replace( "\r\n"_L1, "_"_L1 );
  layerName.replace( '\r', '_' );
  layerName.replace( '\n', '_' );
 
  return layerName.trimmed();
}
 
bool QgsDxfExport::layerIsScaleBasedVisible( const QgsMapLayer *layer ) const
{
  if ( !layer )
    return false;
 
  if ( mSymbologyExport == Qgis::FeatureSymbologyExport::NoSymbology )
    return true;
 
  return layer->isInScaleRange( mSymbologyScale );
}
 
QString QgsDxfExport::layerName( const QString &id, const QgsFeature &f ) const
{
  // TODO: make this thread safe
  for ( QgsMapLayer *ml : std::as_const( mLayerList ) )
  {
    QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( ml );
    if ( vl && vl->id() == id )
    {
      int attrIdx = mLayerNameAttribute.value( vl->id(), -1 );
      return dxfLayerName( attrIdx < 0 ? layerName( vl ) : f.attribute( attrIdx ).toString() );
    }
  }
 
  return u"0"_s;
}
 
QString QgsDxfExport::dxfEncoding( const QString &name )
{
  const QByteArray codec = name.toLocal8Bit();
  if ( QTextCodec::codecForName( codec ) )
  {
    int i;
    for ( i = 0; i < static_cast< int >( sizeof( DXF_ENCODINGS ) / sizeof( *DXF_ENCODINGS ) ) && strcasecmp( codec.data(), DXF_ENCODINGS[i][1] ) != 0; ++i )
      ;
 
    if ( i != static_cast< int >( sizeof( DXF_ENCODINGS ) / sizeof( *DXF_ENCODINGS ) ) )
    {
      return DXF_ENCODINGS[i][0];
    }
  }
 
  return QString();
}
 
QStringList QgsDxfExport::encodings()
{
  QStringList encodings;
  const QList< QByteArray > codecs = QTextCodec::availableCodecs();
  encodings.reserve( codecs.size() );
  for ( const QByteArray &codec : codecs )
  {
    int i;
    for ( i = 0; i < static_cast< int >( sizeof( DXF_ENCODINGS ) / sizeof( *DXF_ENCODINGS ) ) && strcasecmp( codec.data(), DXF_ENCODINGS[i][1] ) != 0; ++i )
      ;
 
    if ( i < static_cast< int >( sizeof( DXF_ENCODINGS ) / sizeof( *DXF_ENCODINGS ) ) )
      encodings << codec.data();
  }
 
  encodings.removeDuplicates();
 
  return encodings;
}
 
QString QgsDxfExport::layerName( QgsVectorLayer *vl ) const
{
  Q_ASSERT( vl );
  auto overriddenNameIt = mLayerOverriddenName.constFind( vl->id() );
  if ( overriddenNameIt != mLayerOverriddenName.constEnd() && !overriddenNameIt.value().isEmpty() )
  {
    return overriddenNameIt.value();
  }
  else if ( mLayerTitleAsName && ( !vl->metadata().title().isEmpty() || !vl->serverProperties()->title().isEmpty() ) )
  {
    return !vl->metadata().title().isEmpty() ? vl->metadata().title() : vl->serverProperties()->title();
  }
  else
  {
    return vl->name();
  }
}
 
void QgsDxfExport::drawLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings )
{
  if ( !settings.drawLabels )
    return;
 
  QgsTextLabelFeature *lf = dynamic_cast<QgsTextLabelFeature *>( label->getFeaturePart()->feature() );
  if ( !lf )
    return;
 
  // Copy to temp, editable layer settings
  // these settings will be changed by any data defined values, then used for rendering label components
  // settings may be adjusted during rendering of components
  QgsPalLayerSettings tmpLyr( settings );
 
  // apply any previously applied data defined settings for the label
  const QMap< QgsPalLayerSettings::Property, QVariant > &ddValues = lf->dataDefinedValues();
 
  //font
  QFont dFont = lf->definedFont();
  QgsDebugMsgLevel( u"PAL font tmpLyr: %1, Style: %2"_s.arg( tmpLyr.format().font().toString(), tmpLyr.format().font().styleName() ), 4 );
  QgsDebugMsgLevel( u"PAL font definedFont: %1, Style: %2"_s.arg( dFont.toString(), dFont.styleName() ), 4 );
 
  QgsTextFormat format = tmpLyr.format();
  format.setFont( dFont );
  tmpLyr.setFormat( format );
 
  if ( tmpLyr.multilineAlign == Qgis::LabelMultiLineAlignment::FollowPlacement )
  {
    //calculate font alignment based on label quadrant
    switch ( label->quadrant() )
    {
      case Qgis::LabelQuadrantPosition::AboveLeft:
      case Qgis::LabelQuadrantPosition::Left:
      case Qgis::LabelQuadrantPosition::BelowLeft:
        tmpLyr.multilineAlign = Qgis::LabelMultiLineAlignment::Right;
        break;
      case Qgis::LabelQuadrantPosition::Above:
      case Qgis::LabelQuadrantPosition::Over:
      case Qgis::LabelQuadrantPosition::Below:
        tmpLyr.multilineAlign = Qgis::LabelMultiLineAlignment::Center;
        break;
      case Qgis::LabelQuadrantPosition::AboveRight:
      case Qgis::LabelQuadrantPosition::Right:
      case Qgis::LabelQuadrantPosition::BelowRight:
        tmpLyr.multilineAlign = Qgis::LabelMultiLineAlignment::Left;
        break;
    }
  }
 
  // update tmpLyr with any data defined text style values
  QgsPalLabeling::dataDefinedTextStyle( tmpLyr, ddValues );
 
  // update tmpLyr with any data defined text buffer values
  QgsPalLabeling::dataDefinedTextBuffer( tmpLyr, ddValues );
 
  // update tmpLyr with any data defined text formatting values
  QgsPalLabeling::dataDefinedTextFormatting( tmpLyr, ddValues );
 
  // add to the results
  QString txt = label->getFeaturePart()->feature()->labelText();
 
  QgsFeatureId fid = label->getFeaturePart()->featureId();
  QString dxfLayer = mDxfLayerNames[layerId][fid];
 
  QString wrapchr = tmpLyr.wrapChar.isEmpty() ? u"\n"_s : tmpLyr.wrapChar;
 
  //add the direction symbol if needed
  if ( !txt.isEmpty() && tmpLyr.placement == Qgis::LabelPlacement::Line && tmpLyr.lineSettings().addDirectionSymbol() )
  {
    bool prependSymb = false;
    QString symb = tmpLyr.lineSettings().rightDirectionSymbol();
 
    if ( label->isReversedFromLineDirection() )
    {
      prependSymb = true;
      symb = tmpLyr.lineSettings().leftDirectionSymbol();
    }
 
    if ( tmpLyr.lineSettings().reverseDirectionSymbol() )
    {
      if ( symb == tmpLyr.lineSettings().rightDirectionSymbol() )
      {
        prependSymb = true;
        symb = tmpLyr.lineSettings().leftDirectionSymbol();
      }
      else
      {
        prependSymb = false;
        symb = tmpLyr.lineSettings().rightDirectionSymbol();
      }
    }
 
    switch ( tmpLyr.lineSettings().directionSymbolPlacement() )
    {
      case QgsLabelLineSettings::DirectionSymbolPlacement::SymbolAbove:
        prependSymb = true;
        symb = symb + wrapchr;
        break;
 
      case QgsLabelLineSettings::DirectionSymbolPlacement::SymbolBelow:
        prependSymb = false;
        symb = wrapchr + symb;
        break;
 
      case QgsLabelLineSettings::DirectionSymbolPlacement::SymbolLeftRight:
        break;
    }
 
    if ( prependSymb )
    {
      txt.prepend( symb );
    }
    else
    {
      txt.append( symb );
    }
  }
 
  if ( mFlags & FlagNoMText )
  {
    txt.replace( QChar( QChar::LineFeed ), ' ' );
    txt.replace( QChar( QChar::CarriageReturn ), ' ' );
    writeText( dxfLayer, txt, label, tmpLyr, context.expressionContext() );
  }
  else
  {
    txt.replace( QString( QChar( QChar::CarriageReturn ) ) + QString( QChar( QChar::LineFeed ) ), u"\\P"_s );
    txt.replace( QChar( QChar::CarriageReturn ), u"\\P"_s );
    txt = txt.replace( wrapchr, "\\P"_L1 );
    txt.replace( " "_L1, "\\~"_L1 );
 
    if ( tmpLyr.format().font().underline() )
    {
      txt.prepend( "\\L" ).append( "\\l" );
    }
 
    if ( tmpLyr.format().font().overline() )
    {
      txt.prepend( "\\O" ).append( "\\o" );
    }
 
    if ( tmpLyr.format().font().strikeOut() )
    {
      txt.prepend( "\\K" ).append( "\\k" );
    }
 
    txt.prepend( u"\\f%1|i%2|b%3;\\H%4;"_s.arg( tmpLyr.format().font().family() )
                   .arg( tmpLyr.format().font().italic() ? 1 : 0 )
                   .arg( tmpLyr.format().font().bold() ? 1 : 0 )
                   .arg( label->getHeight() / ( 1 + txt.count( u"\\P"_s ) ) * 0.75 ) );
    writeMText( dxfLayer, txt, QgsPoint( label->getX(), label->getY() ), label->getWidth(), label->getAlpha() * 180.0 / M_PI, tmpLyr.format().color() );
  }
}
 
 
void QgsDxfExport::registerDxfLayer( const QString &layerId, QgsFeatureId fid, const QString &layerName )
{
  if ( !mDxfLayerNames.contains( layerId ) )
    mDxfLayerNames[layerId] = QMap<QgsFeatureId, QString>();
 
  mDxfLayerNames[layerId][fid] = layerName;
}
 
void QgsDxfExport::setDestinationCrs( const QgsCoordinateReferenceSystem &crs )
{
  mCrs = crs;
  mMapUnits = crs.mapUnits();
}
 
QgsCoordinateReferenceSystem QgsDxfExport::destinationCrs() const
{
  return mCrs;
}
 
QString QgsDxfExport::DxfLayer::splitLayerAttribute() const
{
  QString splitLayerFieldName;
  const QgsFields fields = mLayer->fields();
  if ( mLayerOutputAttributeIndex >= 0 && mLayerOutputAttributeIndex < fields.size() )
  {
    splitLayerFieldName = fields.at( mLayerOutputAttributeIndex ).name();
  }
 
  return splitLayerFieldName;
}
 
void QgsDxfExport::createDDBlockInfo()
{
  int symbolLayerNr = 0;
  for ( DxfLayerJob *job : std::as_const( mJobs ) )
  {
    int ddMaxNumberOfClasses = -1;
    bool createDDBlocks = mLayerDDBlockMaxNumberOfClasses.contains( job->featureSource.id() );
    if ( createDDBlocks )
    {
      ddMaxNumberOfClasses = mLayerDDBlockMaxNumberOfClasses[job->featureSource.id()];
    }
    else
    {
      continue;
    }
 
    const QgsSymbolList symbols = job->renderer->symbols( mRenderContext );
 
    for ( const QgsSymbol *symbol : symbols )
    {
      //Create blocks only for marker symbols
      if ( symbol->type() != Qgis::SymbolType::Marker )
      {
        continue;
      }
 
      int maxSymbolLayers = symbol->symbolLayerCount();
      if ( mSymbologyExport != Qgis::FeatureSymbologyExport::PerSymbolLayer )
      {
        maxSymbolLayers = 1;
      }
 
      for ( int i = 0; i < maxSymbolLayers; ++i )
      {
        const QgsSymbolLayer *sl = symbol->symbolLayer( i );
        if ( !sl )
        {
          continue;
        }
        QgsPropertyCollection properties = sl->dataDefinedProperties();
 
        if ( !hasBlockBreakingDataDefinedProperties( sl, symbol ) || !createDDBlocks )
        {
          ++symbolLayerNr;
          continue;
        }
 
        //iterate layer, evaluate value and get symbology hash groups
        QgsSymbolRenderContext sctx( mRenderContext, Qgis::RenderUnit::Millimeters, 1.0, false, Qgis::SymbolRenderHints(), nullptr );
        const QgsCoordinateTransform ct( job->crs, mMapSettings.destinationCrs(), mMapSettings.transformContext() );
        QgsFeatureRequest request
          = QgsFeatureRequest().setSubsetOfAttributes( job->attributes, job->fields ).setFlags( Qgis::FeatureRequestFlag::NoGeometry ).setExpressionContext( job->renderContext.expressionContext() );
        QgsCoordinateTransform extentTransform = ct;
        extentTransform.setBallparkTransformsAreAppropriate( true );
        try
        {
          request.setFilterRect( extentTransform.transformBoundingBox( mExtent, Qgis::TransformDirection::Reverse ) );
        }
        catch ( QgsCsException &e )
        {
          QgsDebugError( u"Could not transform extent to layer extent: %1"_s.arg( e.what() ) );
          continue;
        }
 
        QgsFeatureIterator featureIt = job->featureSource.getFeatures( request );
 
        QHash<uint, QPair<int, DataDefinedBlockInfo> > blockSymbolMap; //symbolHash/occurrences/block Text
 
        QgsFeature fet;
        while ( featureIt.nextFeature( fet ) )
        {
          uint symbolHash = dataDefinedSymbolClassHash( fet, properties, sctx.renderContext().expressionContext() );
          if ( blockSymbolMap.contains( symbolHash ) )
          {
            blockSymbolMap[symbolHash].first += 1;
            continue;
          }
 
          sctx.setFeature( &fet );
          sctx.renderContext().expressionContext().setFeature( fet );
 
          DataDefinedBlockInfo blockInfo;
          blockInfo.blockName = u"symbolLayer%1class%2"_s.arg( symbolLayerNr ).arg( symbolHash );
          blockInfo.angle = sl->dxfAngle( sctx );
          blockInfo.size = sl->dxfSize( sctx );
          blockInfo.feature = fet;
 
          blockSymbolMap.insert( symbolHash, qMakePair( 1, blockInfo ) );
        }
        ++symbolLayerNr;
 
        //keep the entries with the most frequent occurrences
        QMultiMap<int, uint> occurrences;
        QHash<uint, QPair<int, DataDefinedBlockInfo> >::const_iterator blockSymbolIt = blockSymbolMap.constBegin();
        for ( ; blockSymbolIt != blockSymbolMap.constEnd(); ++blockSymbolIt )
        {
          occurrences.insert( blockSymbolIt.value().first, blockSymbolIt.key() );
        }
 
        QHash<uint, DataDefinedBlockInfo > applyBlockSymbolMap;
        int nInsertedClasses = 0;
        QMultiMap<int, uint>::const_iterator occIt = occurrences.constEnd();
        while ( occurrences.size() > 0 && occIt != occurrences.constBegin() )
        {
          --occIt;
          applyBlockSymbolMap.insert( occIt.value(), blockSymbolMap[occIt.value()].second );
          ++nInsertedClasses;
          if ( ddMaxNumberOfClasses != -1 && nInsertedClasses >= ddMaxNumberOfClasses )
          {
            break;
          }
        }
 
        //add to mDataDefinedBlockInfo
        mDataDefinedBlockInfo.insert( sl, applyBlockSymbolMap );
      }
    }
  }
}