C++ QgsMultiPolyline类代码示例

QDomElement QgsWFSServer::createMultiLineStringElem( QgsGeometry* geom, QDomDocument& doc ) const
{
  if ( !geom )
  {
    return QDomElement();
  }

  QDomElement multiLineStringElem = doc.createElement( "gml:MultiLineString" );
  QgsMultiPolyline multiline = geom->asMultiPolyline();

  QgsMultiPolyline::const_iterator multiLineIt = multiline.constBegin();
  for ( ; multiLineIt != multiline.constEnd(); ++multiLineIt )
  {
    QgsGeometry* lineGeom = QgsGeometry::fromPolyline( *multiLineIt );
    if ( lineGeom )
    {
      QDomElement lineStringMemberElem = doc.createElement( "gml:lineStringMember" );
      QDomElement lineElem = createLineStringElem( lineGeom, doc );
      lineStringMemberElem.appendChild( lineElem );
      multiLineStringElem.appendChild( lineStringMemberElem );
    }
    delete lineGeom;
  }

  return multiLineStringElem;
}

QgsGeometry* QgsTransectSample::closestMultilineElement( const QgsPoint& pt, QgsGeometry* multiLine )
{
  if ( !multiLine || ( multiLine->wkbType() != QGis::WKBMultiLineString
                       && multiLine->wkbType() != QGis::WKBMultiLineString25D ) )
  {
    return 0;
  }

  double minDist = DBL_MAX;
  double currentDist = 0;
  QgsGeometry* currentLine = 0;
  QgsGeometry* closestLine = 0;
  QgsGeometry* pointGeom = QgsGeometry::fromPoint( pt );

  QgsMultiPolyline multiPolyline = multiLine->asMultiPolyline();
  QgsMultiPolyline::const_iterator it = multiPolyline.constBegin();
  for ( ; it != multiPolyline.constEnd(); ++it )
  {
    currentLine = QgsGeometry::fromPolyline( *it );
    currentDist = pointGeom->distance( *currentLine );
    if ( currentDist < minDist )
    {
      minDist = currentDist;
      closestLine = currentLine;
    }
    else
    {
      delete currentLine;
    }
  }

  delete pointGeom;
  return closestLine;
}

QgsGeometry* QgsMapToolOffsetCurve::convertToSingleLine( QgsGeometry* geom, int vertex, bool& isMulti )
{
  if ( !geom )
  {
    return 0;
  }

  isMulti = false;
  QGis::WkbType geomType = geom->wkbType();
  if ( geomType == QGis::WKBLineString || geomType == QGis::WKBLineString25D )
  {
    return geom;
  }
  else if ( geomType == QGis::WKBMultiLineString || geomType == QGis::WKBMultiLineString25D )
  {
    //search vertex
    isMulti = true;
    int currentVertex = 0;
    QgsMultiPolyline multiLine = geom->asMultiPolyline();
    QgsMultiPolyline::const_iterator it = multiLine.constBegin();
    for ( ; it != multiLine.constEnd(); ++it )
    {
      currentVertex += it->size();
      if ( vertex < currentVertex )
      {
        QgsGeometry* g = QgsGeometry::fromPolyline( *it );
        delete geom;
        return g;
      }
    }
  }
  delete geom;
  return 0;
}

QgsGeometry QgsTransectSample::closestMultilineElement( const QgsPoint& pt, const QgsGeometry& multiLine )
{
  if ( !multiLine || ( multiLine.wkbType() != QgsWkbTypes::MultiLineString
                       && multiLine.wkbType() != QgsWkbTypes::MultiLineString25D ) )
  {
    return QgsGeometry();
  }

  double minDist = DBL_MAX;
  double currentDist = 0;
  QgsGeometry currentLine;
  QgsGeometry closestLine;
  QgsGeometry pointGeom = QgsGeometry::fromPoint( pt );

  QgsMultiPolyline multiPolyline = multiLine.asMultiPolyline();
  QgsMultiPolyline::const_iterator it = multiPolyline.constBegin();
  for ( ; it != multiPolyline.constEnd(); ++it )
  {
    currentLine = QgsGeometry::fromPolyline( *it );
    currentDist = pointGeom.distance( currentLine );
    if ( currentDist < minDist )
    {
      minDist = currentDist;
      closestLine = currentLine;
    }
  }

  return closestLine;
}

std::unique_ptr<QgsMultiLineString> QgsGeometryFactory::fromMultiPolyline( const QgsMultiPolyline &multiline )
{
  std::unique_ptr< QgsMultiLineString > mLine( new QgsMultiLineString() );
  for ( int i = 0; i < multiline.size(); ++i )
  {
    mLine->addGeometry( fromPolyline( multiline.at( i ) ).release() );
  }
  return mLine;
}

QgsGeometry *QgsRubberBand::asGeometry()
{
  QgsGeometry *geom = NULL;

  switch ( mGeometryType )
  {
    case QGis::Polygon:
    {
      QgsPolygon polygon;
      QList< QList<QgsPoint> >::const_iterator it = mPoints.constBegin();
      for ( ; it != mPoints.constEnd(); ++it )
      {
        polygon.append( getPolyline( *it ) );
      }
      geom = QgsGeometry::fromPolygon( polygon );
      break;
    }

    case QGis::Point:
    {
      QgsMultiPoint multiPoint;

      QList< QList<QgsPoint> >::const_iterator it = mPoints.constBegin();
      for ( ; it != mPoints.constEnd(); ++it )
      {
        multiPoint += getPolyline( *it );
      }
      geom = QgsGeometry::fromMultiPoint( multiPoint );
      break;
    }

    case QGis::Line:
    default:
    {
      if ( mPoints.size() > 0 )
      {
        if ( mPoints.size() > 1 )
        {
          QgsMultiPolyline multiPolyline;
          QList< QList<QgsPoint> >::const_iterator it = mPoints.constBegin();
          for ( ; it != mPoints.constEnd(); ++it )
          {
            multiPolyline.append( getPolyline( *it ) );
          }
          geom = QgsGeometry::fromMultiPolyline( multiPolyline );
        }
        else
        {
          geom = QgsGeometry::fromPolyline( getPolyline( mPoints[0] ) );
        }
      }
      break;
    }
  }
  return geom;
}

int QgsMapToolDeletePart::partNumberOfVertex( QgsGeometry* g, int beforeVertexNr )
{
  int part;

  switch ( g->wkbType() )
  {
    case QGis::WKBMultiPoint25D:
    case QGis::WKBMultiPoint:
      if ( beforeVertexNr < g->asMultiPoint().count() )
        return beforeVertexNr;
      else
        return -1;

    case QGis::WKBMultiLineString25D:
    case QGis::WKBMultiLineString:
    {
      QgsMultiPolyline mline = g->asMultiPolyline();
      for ( part = 0; part < mline.count(); part++ )
      {
        if ( beforeVertexNr < mline[part].count() )
          return part;

        beforeVertexNr -= mline[part].count();
      }
      return -1; // not found
    }

    case QGis::WKBMultiPolygon25D:
    case QGis::WKBMultiPolygon:
    {
      QgsMultiPolygon mpolygon = g->asMultiPolygon();
      for ( part = 0; part < mpolygon.count(); part++ ) // go through the polygons
      {
        const QgsPolygon& polygon = mpolygon[part];
        for ( int ring = 0; ring < polygon.count(); ring++ ) // go through the rings
        {
          if ( beforeVertexNr < polygon[ring].count() )
            return part;

          beforeVertexNr -= polygon[ring].count();
        }
      }
      return -1; // not found
    }

    default:
      return -1;
  }
}

QgsGeometry* QgsGeometryAnalyzer::locateBetweenMeasures( double fromMeasure, double toMeasure, QgsGeometry* lineGeom )
{
  if ( !lineGeom )
  {
    return 0;
  }

  QgsMultiPolyline resultGeom;

  //need to go with WKB and z coordinate until QgsGeometry supports M values
  unsigned char* lineWkb = lineGeom->asWkb();

  unsigned char* ptr = lineWkb + 1;
  QGis::WkbType wkbType;
  memcpy( &wkbType, ptr, sizeof( wkbType ) );
  ptr += sizeof( wkbType );

  if ( wkbType != QGis::WKBLineString25D && wkbType != QGis::WKBMultiLineString25D )
  {
    return 0;
  }

  if ( wkbType == QGis::WKBLineString25D )
  {
    locateBetweenWkbString( ptr, resultGeom, fromMeasure, toMeasure );
  }
  else if ( wkbType == QGis::WKBMultiLineString25D )
  {
    int* nLines = ( int* )ptr;
    ptr += sizeof( int );
    for ( int i = 0; i < *nLines; ++i )
    {
      ptr += ( 1 + sizeof( wkbType ) );
      ptr = locateBetweenWkbString( ptr, resultGeom, fromMeasure, toMeasure );
    }
  }

  if ( resultGeom.size() < 1 )
  {
    return 0;
  }
  return QgsGeometry::fromMultiPolyline( resultGeom );
}

QgsGeometry* QgsTransectSample::clipBufferLine( const QgsGeometry& stratumGeom, QgsGeometry* clippedBaseline, double tolerance )
{
  if ( !stratumGeom || !clippedBaseline || clippedBaseline->wkbType() == QgsWkbTypes::Unknown )
  {
    return nullptr;
  }

  QgsGeometry usedBaseline = *clippedBaseline;
  if ( mBaselineSimplificationTolerance >= 0 )
  {
    //int verticesBefore = usedBaseline->asMultiPolyline().count();
    usedBaseline = clippedBaseline->simplify( mBaselineSimplificationTolerance );
    if ( usedBaseline.isEmpty() )
    {
      return nullptr;
    }
    //int verticesAfter = usedBaseline->asMultiPolyline().count();

    //debug: write to file
    /*QgsVectorFileWriter debugWriter( "/tmp/debug.shp", "utf-8", QgsFields(), QgsWkbTypes::LineString, &( mStrataLayer->crs() ) );
    QgsFeature debugFeature; debugFeature.setGeometry( usedBaseline );
    debugWriter.addFeature( debugFeature );*/
  }

  double currentBufferDist = tolerance;
  int maxLoops = 10;

  for ( int i = 0; i < maxLoops; ++i )
  {
    //loop with tolerance: create buffer, convert buffer to line, clip line by stratum, test if result is (single) line
    QgsGeometry clipBaselineBuffer = usedBaseline.buffer( currentBufferDist, 8 );
    if ( clipBaselineBuffer.isEmpty() )
    {
      continue;
    }

    //it is also possible that clipBaselineBuffer is a multipolygon
    QgsGeometry bufferLine; //buffer line or multiline
    QgsGeometry bufferLineClipped;
    QgsMultiPolyline mpl;
    if ( clipBaselineBuffer.isMultipart() )
    {
      QgsMultiPolygon bufferMultiPolygon = clipBaselineBuffer.asMultiPolygon();
      if ( bufferMultiPolygon.size() < 1 )
      {
        continue;
      }

      for ( int j = 0; j < bufferMultiPolygon.size(); ++j )
      {
        int size = bufferMultiPolygon.at( j ).size();
        for ( int k = 0; k < size; ++k )
        {
          mpl.append( bufferMultiPolygon.at( j ).at( k ) );
        }
      }
      bufferLine = QgsGeometry::fromMultiPolyline( mpl );
    }
    else
    {
      QgsPolygon bufferPolygon = clipBaselineBuffer.asPolygon();
      if ( bufferPolygon.size() < 1 )
      {
        continue;
      }

      int size = bufferPolygon.size();
      mpl.reserve( size );
      for ( int j = 0; j < size; ++j )
      {
        mpl.append( bufferPolygon[j] );
      }
      bufferLine = QgsGeometry::fromMultiPolyline( mpl );
    }
    bufferLineClipped = bufferLine.intersection( stratumGeom );

    if ( bufferLineClipped.isEmpty() && bufferLineClipped.type() == QgsWkbTypes::LineGeometry )
    {
      //if stratumGeom is a multipolygon, bufferLineClipped must intersect each part
      bool bufferLineClippedIntersectsStratum = true;
      if ( stratumGeom.wkbType() == QgsWkbTypes::MultiPolygon || stratumGeom.wkbType() == QgsWkbTypes::MultiPolygon25D )
      {
        QVector<QgsPolygon> multiPoly = stratumGeom.asMultiPolygon();
        QVector<QgsPolygon>::const_iterator multiIt = multiPoly.constBegin();
        for ( ; multiIt != multiPoly.constEnd(); ++multiIt )
        {
          QgsGeometry poly = QgsGeometry::fromPolygon( *multiIt );
          if ( !poly.intersects( bufferLineClipped ) )
          {
            bufferLineClippedIntersectsStratum = false;
            break;
          }
        }
      }

      if ( bufferLineClippedIntersectsStratum )
      {
        return new QgsGeometry( bufferLineClipped );
      }
    }
//.........这里部分代码省略.........

/*!
  Draw the shape in response to an update event.
  */
void QgsHighlight::paint( QPainter* p )
{
  if ( !mGeometry )
  {
    return;
  }

  p->setPen( mPen );
  p->setBrush( mBrush );

  switch ( mGeometry->wkbType() )
  {
    case QGis::WKBPoint:
    case QGis::WKBPoint25D:
    {
      paintPoint( p, mGeometry->asPoint() );
    }
    break;

    case QGis::WKBMultiPoint:
    case QGis::WKBMultiPoint25D:
    {
      QgsMultiPoint m = mGeometry->asMultiPoint();
      for ( int i = 0; i < m.size(); i++ )
      {
        paintPoint( p, m[i] );
      }
    }
    break;

    case QGis::WKBLineString:
    case QGis::WKBLineString25D:
    {
      paintLine( p, mGeometry->asPolyline() );
    }
    break;

    case QGis::WKBMultiLineString:
    case QGis::WKBMultiLineString25D:
    {
      QgsMultiPolyline m = mGeometry->asMultiPolyline();

      for ( int i = 0; i < m.size(); i++ )
      {
        paintLine( p, m[i] );
      }
    }
    break;

    case QGis::WKBPolygon:
    case QGis::WKBPolygon25D:
    {
      paintPolygon( p, mGeometry->asPolygon() );
    }
    break;

    case QGis::WKBMultiPolygon:
    case QGis::WKBMultiPolygon25D:
    {
      QgsMultiPolygon m = mGeometry->asMultiPolygon();
      for ( int i = 0; i < m.size(); i++ )
      {
        paintPolygon( p, m[i] );
      }
    }
    break;

    case QGis::WKBUnknown:
    default:
      return;
  }
}

void QgsGeometryValidator::run()
{
  mErrorCount = 0;
  QSettings settings;
  if ( settings.value( QStringLiteral( "/qgis/digitizing/validate_geometries" ), 1 ).toInt() == 2 )
  {
    char *r = nullptr;
    const GEOSGeometry *g0 = mG.asGeos();
    GEOSContextHandle_t handle = QgsGeometry::getGEOSHandler();
    if ( !g0 )
    {
      emit errorFound( QgsGeometry::Error( QObject::tr( "GEOS error:could not produce geometry for GEOS (check log window)" ) ) );
    }
    else
    {
      GEOSGeometry *g1 = nullptr;
      if ( GEOSisValidDetail_r( handle, g0, GEOSVALID_ALLOW_SELFTOUCHING_RING_FORMING_HOLE, &r, &g1 ) != 1 )
      {
        if ( g1 )
        {
          const GEOSCoordSequence *cs = GEOSGeom_getCoordSeq_r( handle, g1 );

          unsigned int n;
          if ( GEOSCoordSeq_getSize_r( handle, cs, &n ) && n == 1 )
          {
            double x, y;
            GEOSCoordSeq_getX_r( handle, cs, 0, &x );
            GEOSCoordSeq_getY_r( handle, cs, 0, &y );
            emit errorFound( QgsGeometry::Error( QObject::tr( "GEOS error:%1" ).arg( r ), QgsPoint( x, y ) ) );
            mErrorCount++;
          }

          GEOSGeom_destroy_r( handle, g1 );
        }
        else
        {
          emit errorFound( QgsGeometry::Error( QObject::tr( "GEOS error:%1" ).arg( r ) ) );
          mErrorCount++;
        }

        GEOSFree_r( handle, r );
      }
    }

    return;
  }

  QgsDebugMsg( "validation thread started." );

  QgsWkbTypes::Type flatType = QgsWkbTypes::flatType( mG.wkbType() );
  //if ( flatType == QgsWkbTypes::Point || flatType == QgsWkbTypes::MultiPoint )
  //    break;
  if ( flatType == QgsWkbTypes::LineString )
  {
    validatePolyline( 0, mG.asPolyline() );
  }
  else if ( flatType == QgsWkbTypes::MultiLineString )
  {
    QgsMultiPolyline mp = mG.asMultiPolyline();
    for ( int i = 0; !mStop && i < mp.size(); i++ )
      validatePolyline( i, mp[i] );
  }
  else if ( flatType == QgsWkbTypes::Polygon )
  {
    validatePolygon( 0, mG.asPolygon() );
  }
  else if ( flatType == QgsWkbTypes::MultiPolygon )
  {
    QgsMultiPolygon mp = mG.asMultiPolygon();
    for ( int i = 0; !mStop && i < mp.size(); i++ )
    {
      validatePolygon( i, mp[i] );
    }

    for ( int i = 0; !mStop && i < mp.size(); i++ )
    {
      if ( mp[i].isEmpty() )
      {
        emit errorFound( QgsGeometry::Error( QObject::tr( "polygon %1 has no rings" ).arg( i ) ) );
        mErrorCount++;
        continue;
      }

      for ( int j = i + 1;  !mStop && j < mp.size(); j++ )
      {
        if ( mp[j].isEmpty() )
          continue;

        if ( ringInRing( mp[i][0], mp[j][0] ) )
        {
          emit errorFound( QgsGeometry::Error( QObject::tr( "polygon %1 inside polygon %2" ).arg( i ).arg( j ) ) );
          mErrorCount++;
        }
        else if ( ringInRing( mp[j][0], mp[i][0] ) )
        {
          emit errorFound( QgsGeometry::Error( QObject::tr( "polygon %1 inside polygon %2" ).arg( j ).arg( i ) ) );
          mErrorCount++;
        }
        else
        {
//.........这里部分代码省略.........

ErrorList topolTest::checkSegmentLength( double tolerance, QgsVectorLayer* layer1, QgsVectorLayer* layer2, bool isExtent )
{
  Q_UNUSED( layer1 );
  Q_UNUSED( layer2 );
  Q_UNUSED( isExtent );

  int i = 0;
  ErrorList errorList;
  QgsFeature f;


  QList<FeatureLayer>::Iterator it;
  QList<FeatureLayer>::ConstIterator FeatureListEnd = mFeatureList1.end();

  QgsPolygon pol;

  QgsMultiPolygon mpol;
  QgsPolyline segm;
  QgsPolyline ls;
  QgsMultiPolyline mls;
  QList<FeatureLayer> fls;
  TopolErrorShort* err;
  double distance;

  for ( it = mFeatureList1.begin(); it != FeatureListEnd; ++it )
  {
    if ( !( ++i % 100 ) )
    {
      emit progress( i );
    }

    if ( testCancelled() )
    {
      break;
    }

    QgsGeometry* g1 = it->feature.geometry();


    // switching by type here, because layer can contain both single and multi version geometries
    switch ( g1->wkbType() )
    {
      case QGis::WKBLineString:
      case QGis::WKBLineString25D:
        ls = g1->asPolyline();


        for ( int i = 1; i < ls.size(); ++i )
        {
          distance = sqrt( ls[i-1].sqrDist( ls[i] ) );
          if ( distance < tolerance )
          {
            fls.clear();
            fls << *it << *it;
            segm.clear();
            segm << ls[i-1] << ls[i];
            QgsGeometry* conflict = QgsGeometry::fromPolyline( segm );
            err = new TopolErrorShort( g1->boundingBox(), conflict, fls );
            //err = new TopolErrorShort(g1->boundingBox(), QgsGeometry::fromPolyline(segm), fls);
            errorList << err;
            //break on getting the first error
            break;
          }
        }
        break;

      case QGis::WKBPolygon:
      case QGis::WKBPolygon25D:
        pol = g1->asPolygon();

        for ( int i = 0; i < pol.size(); ++i )
        {
          for ( int j = 1; j < pol[i].size(); ++j )
          {
            distance =  sqrt( pol[i][j-1].sqrDist( pol[i][j] ) );
            if ( distance < tolerance )
            {
              fls.clear();
              fls << *it << *it;
              segm.clear();
              segm << pol[i][j-1] << pol[i][j];
              QgsGeometry* conflict = QgsGeometry::fromPolyline( segm );
              err = new TopolErrorShort( g1->boundingBox(), conflict, fls );
              errorList << err;
              //break on getting the first error
              break;
            }
          }
        }

        break;

      case QGis::WKBMultiLineString:
      case QGis::WKBMultiLineString25D:
        mls = g1->asMultiPolyline();

        for ( int k = 0; k < mls.size(); ++k )
        {
          QgsPolyline& ls = mls[k];
          for ( int i = 1; i < ls.size(); ++i )
//.........这里部分代码省略.........

QgsGeometry* QgsMapToolDeletePart::partUnderPoint( QPoint point, QgsFeatureId& fid, int& partNum )
{
  QgsFeature f;
  QgsGeometry* geomPart = new QgsGeometry();

  switch ( vlayer->geometryType() )
  {
    case QGis::Point:
    case QGis::Line:
    {
      QgsPointLocator::Match match = mCanvas->snappingUtils()->snapToCurrentLayer( point, QgsPointLocator::Vertex | QgsPointLocator::Edge );
      if ( !match.isValid() )
        return geomPart;

      int snapVertex = match.vertexIndex();
      vlayer->getFeatures( QgsFeatureRequest().setFilterFid( match.featureId() ) ).nextFeature( f );
      const QgsGeometry* g = f.constGeometry();
      if ( !g->isMultipart() )
      {
        fid = match.featureId();
        delete geomPart;
        return QgsGeometry::fromPoint( match.point() );
      }
      if ( g->wkbType() == QGis::WKBMultiPoint || g->wkbType() == QGis::WKBMultiPoint25D )
      {
        fid = match.featureId();
        partNum = snapVertex;
        delete geomPart;
        return QgsGeometry::fromPoint( match.point() );
      }
      if ( g->wkbType() == QGis::WKBMultiLineString || g->wkbType() == QGis::WKBMultiLineString25D )
      {
        QgsMultiPolyline mline = g->asMultiPolyline();
        for ( int part = 0; part < mline.count(); part++ )
        {
          if ( snapVertex < mline[part].count() )
          {
            fid = match.featureId();
            partNum = part;
            delete geomPart;
            return QgsGeometry::fromPolyline( mline[part] );
          }
          snapVertex -= mline[part].count();
        }
      }
      break;
    }
    case QGis::Polygon:
    {
      QgsPoint layerCoords = toLayerCoordinates( vlayer, point );
      double searchRadius = QgsTolerance::vertexSearchRadius( mCanvas->currentLayer(), mCanvas->mapSettings() );
      QgsRectangle selectRect( layerCoords.x() - searchRadius, layerCoords.y() - searchRadius,
                               layerCoords.x() + searchRadius, layerCoords.y() + searchRadius );
      QgsFeatureIterator fit = vlayer->getFeatures( QgsFeatureRequest().setFilterRect( selectRect ) );
      fit.nextFeature( f );
      const QgsGeometry* g = f.constGeometry();
      if ( !g )
        return geomPart;
      if ( !g->isMultipart() )
      {
        fid = f.id();
        return geomPart;
      }
      QgsMultiPolygon mpolygon = g->asMultiPolygon();
      for ( int part = 0; part < mpolygon.count(); part++ ) // go through the polygons
      {
        const QgsPolygon& polygon = mpolygon[part];
        QgsGeometry* partGeo = QgsGeometry::fromPolygon( polygon );
        if ( partGeo->contains( &layerCoords ) )
        {
          fid = f.id();
          partNum = part;
          delete geomPart;
          return partGeo;
        }
        delete partGeo;
      }
      break;
    }
    default:
    {
      break;
    }
  }
  return geomPart;
}

void RgLineVectorLayerDirector::makeGraph( RgGraphBuilder *builder, const QVector< QgsPoint >& additionalPoints,
    QVector< QgsPoint >& tiedPoint ) const
{
  QgsVectorLayer *vl = myLayer();

  if ( vl == NULL )
    return;

  int featureCount = ( int ) vl->featureCount() * 2;
  int step = 0;

  QgsCoordinateTransform ct;
  QgsDistanceArea da;
  ct.setSourceCrs( vl->crs() );

  if ( builder->coordinateTransformEnabled() )
  {
    ct.setDestCRS( builder->destinationCrs() );
    da.setProjectionsEnabled( true );
    //
    //da.setSourceCrs( builder->destinationCrs().srsid() );
    //
  }
  else
  {
    ct.setDestCRS( vl->crs() );
    da.setProjectionsEnabled( false );
  }

  tiedPoint = QVector< QgsPoint >( additionalPoints.size(), QgsPoint( 0.0, 0.0 ) );
  TiePointInfo tmpInfo;
  tmpInfo.mLength = infinity();

  QVector< TiePointInfo > pointLengthMap( additionalPoints.size(), tmpInfo );
  QVector< TiePointInfo >::iterator pointLengthIt;

  // begin: tie points to the graph
  QgsAttributeList la;
  vl->select( la );
  QgsFeature feature;
  while ( vl->nextFeature( feature ) )
  {
    QgsMultiPolyline mpl;
    if ( feature.geometry()->wkbType() == QGis::WKBLineString )
    {
      mpl.push_back( feature.geometry()->asPolyline() );
    }else if ( feature.geometry()->wkbType() == QGis::WKBMultiLineString )
    {
      mpl = feature.geometry()->asMultiPolyline();
    }

    QgsMultiPolyline::iterator mplIt;
    for ( mplIt = mpl.begin(); mplIt != mpl.end(); ++mplIt )
    {
      QgsPoint pt1, pt2;
      bool isFirstPoint = true;
      QgsPolyline::iterator pointIt;
      for ( pointIt = mplIt->begin(); pointIt != mplIt->end(); ++pointIt )
      {
        pt2 = builder->addVertex( ct.transform( *pointIt ) );
        if ( !isFirstPoint )
        {
          int i = 0;
          for ( i = 0; i != additionalPoints.size(); ++i )
          {
            TiePointInfo info;
            if ( pt1 == pt2 )
            {
              info.mLength = additionalPoints[ i ].sqrDist( pt1 );
              info.mTiedPoint = pt1;
            }
            else
            {
              info.mLength = additionalPoints[ i ].sqrDistToSegment( pt1.x(), pt1.y(), pt2.x(), pt2.y(), info.mTiedPoint );
            }
            if ( pointLengthMap[ i ].mLength > info.mLength )
            {
              info.mTiedPoint = builder->addVertex( info.mTiedPoint );
              info.mFirstPoint = pt1;
              info.mLastPoint = pt2;

              pointLengthMap[ i ] = info;
              tiedPoint[ i ] = info.mTiedPoint;
            }
          }
        }
        pt1 = pt2;
        isFirstPoint = false;
      }
    }
    emit buildProgress( ++step, featureCount );
  }
  // end: tie points to graph

  if ( mDirectionFieldId != -1 )
  {
    la.push_back( mDirectionFieldId );
  }
  if ( mSpeedFieldId != -1 )
  {
//.........这里部分代码省略.........

void QgsDxfExport::addFeature( const QgsSymbolV2RenderContext& ctx, const QString& layer, const QgsSymbolLayerV2* symbolLayer, const QgsSymbolV2* symbol )
{
  const QgsFeature* fet = ctx.feature();
  if ( !fet )
  {
    return;
  }

  QgsGeometry* geom = fet->geometry();
  if ( geom )
  {
    int c = 0;
    if ( mSymbologyExport != NoSymbology )
    {
      c = colorFromSymbolLayer( symbolLayer, ctx );
    }
    double width = -1;
    if ( mSymbologyExport != NoSymbology && symbolLayer )
    {
      width = symbolLayer->dxfWidth( *this, ctx );
    }
    QString lineStyleName = "CONTINUOUS";
    if ( mSymbologyExport != NoSymbology )
    {
      lineStyleName = lineStyleFromSymbolLayer( symbolLayer );
    }
    QGis::WkbType geometryType = geom->wkbType();

    //single point
    if ( geometryType == QGis::WKBPoint || geometryType == QGis::WKBPoint25D )
    {
      writePoint( geom->asPoint(), layer, c, fet, symbolLayer, symbol );
    }

    //multipoint
    if ( geometryType == QGis::WKBMultiPoint || geometryType == QGis::WKBMultiPoint25D )
    {
      QgsMultiPoint multiPoint = geom->asMultiPoint();
      QgsMultiPoint::const_iterator it = multiPoint.constBegin();
      for ( ; it != multiPoint.constEnd(); ++it )
      {
        writePoint( *it, layer, c, fet, symbolLayer, symbol );
      }
    }

    //single line
    if ( geometryType == QGis::WKBLineString || geometryType == QGis::WKBLineString25D )
    {
      writePolyline( geom->asPolyline(), layer, lineStyleName, c, width, false );
    }

    //multiline
    if ( geometryType == QGis::WKBMultiLineString || geometryType == QGis::WKBMultiLineString25D )
    {
      QgsMultiPolyline multiLine = geom->asMultiPolyline();
      QgsMultiPolyline::const_iterator lIt = multiLine.constBegin();
      for ( ; lIt != multiLine.constEnd(); ++lIt )
      {
        writePolyline( *lIt, layer, lineStyleName, c, width, false );
      }
    }

    //polygon
    if ( geometryType == QGis::WKBPolygon || geometryType == QGis::WKBPolygon25D )
    {
      QgsPolygon polygon = geom->asPolygon();
      QgsPolygon::const_iterator polyIt = polygon.constBegin();
      for ( ; polyIt != polygon.constEnd(); ++polyIt ) //iterate over rings
      {
        writePolyline( *polyIt, layer, lineStyleName, c, width, true );
      }
    }

    //multipolygon or polygon
    if ( geometryType == QGis::WKBMultiPolygon || geometryType == QGis::WKBMultiPolygon25D )
    {
      QgsMultiPolygon mp = geom->asMultiPolygon();
      QgsMultiPolygon::const_iterator mpIt = mp.constBegin();
      for ( ; mpIt != mp.constEnd(); ++mpIt )
      {
        QgsPolygon::const_iterator polyIt = mpIt->constBegin();
        for ( ; polyIt != mpIt->constEnd(); ++polyIt )
        {
          writePolyline( *polyIt, layer, lineStyleName, c, width, true );
        }
      }
    }
  }
}