tracks_cleaner.cpp

Go to the documentation of this file.

/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2004-2018 Jean-Pierre Charras, jp.charras at wanadoo.fr
 * Copyright (C) 2011 Wayne Stambaugh <[email protected]>
 * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
#include <reporter.h>
#include <board_commit.h>
#include <cleanup_item.h>
#include <connectivity/connectivity_algo.h>
#include <connectivity/connectivity_data.h>
#include <lset.h>
#include <tool/tool_manager.h>
#include <tools/pcb_actions.h>
#include <tools/global_edit_tool.h>
#include <drc/drc_rtree.h>
#include <tracks_cleaner.h>
 
TRACKS_CLEANER::TRACKS_CLEANER( BOARD* aPcb, BOARD_COMMIT& aCommit ) :
 m_brd( aPcb ),
 m_commit( aCommit ),
 m_dryRun( true ),
 m_itemsList( nullptr ),
 m_reporter( nullptr ),
 m_filter( nullptr )
{
}
 
 
/* Main cleaning function.
 * Delete
 * - Redundant points on tracks (merge aligned segments)
 * - vias on pad
 * - null length segments
 */
void TRACKS_CLEANER::CleanupBoard( bool aDryRun,
 std::vector<std::shared_ptr<CLEANUP_ITEM> >* aItemsList,
 bool aRemoveMisConnected, bool aCleanVias, bool aMergeSegments,
 bool aDeleteUnconnected, bool aDeleteTracksinPad,
 bool aDeleteDanglingVias, REPORTER* aReporter )
{
 m_reporter = aReporter;
 bool has_deleted = false;
 
 m_dryRun = aDryRun;
 m_itemsList = aItemsList;
 
 if( m_reporter )
 {
 if( aDryRun )
 m_reporter->Report( _( "Checking null tracks and vias..." ) );
 else
 m_reporter->Report( _( "Removing null tracks and vias..." ) );
 
 wxSafeYield(); // Timeslice to update UI
 }
 
 bool removeNullSegments = aMergeSegments || aRemoveMisConnected;
 cleanup( aCleanVias, removeNullSegments, aMergeSegments /* dup segments*/, aMergeSegments );
 
 if( m_reporter )
 {
 if( aDryRun )
 m_reporter->Report( _( "Checking redundant tracks..." ) );
 else
 m_reporter->Report( _( "Removing redundant tracks..." ) );
 
 wxSafeYield(); // Timeslice to update UI
 }
 
 // If we didn't remove duplicates above, do it now
 if( !aMergeSegments )
 cleanup( false, false, true, false );
 
 if( aRemoveMisConnected )
 {
 if( m_reporter )
 {
 if( aDryRun )
 m_reporter->Report( _( "Checking shorting tracks..." ) );
 else
 m_reporter->Report( _( "Removing shorting tracks..." ) );
 
 wxSafeYield(); // Timeslice to update UI
 }
 
 removeShortingTrackSegments();
 }
 
 if( aDeleteTracksinPad )
 {
 if( m_reporter )
 {
 if( aDryRun )
 m_reporter->Report( _( "Checking tracks in pads..." ) );
 else
 m_reporter->Report( _( "Removing tracks in pads..." ) );
 
 wxSafeYield(); // Timeslice to update UI
 }
 
 deleteTracksInPads();
 }
 
 if( aDeleteUnconnected || aDeleteDanglingVias )
 {
 if( m_reporter )
 {
 if( aDryRun )
 {
 m_reporter->Report( _( "Checking dangling tracks and vias..." ) );
 }
 else
 {
 if( aDeleteUnconnected )
 m_reporter->Report( _( "Removing dangling tracks..." ) );
 
 if( aDeleteDanglingVias )
 m_reporter->Report( _( "Removing dangling vias..." ) );
 }
 
 wxSafeYield(); // Timeslice to update UI
 }
 
 has_deleted = deleteDanglingTracks( aDeleteUnconnected, aDeleteDanglingVias );
 }
 
 if( has_deleted && aMergeSegments )
 {
 if( m_reporter )
 {
 if( aDryRun )
 m_reporter->Report( _( "Checking collinear tracks..." ) );
 else
 m_reporter->Report( _( "Merging collinear tracks..." ) );
 
 wxSafeYield(); // Timeslice to update UI
 }
 
 cleanup( false, false, false, true );
 }
}
 
 
bool TRACKS_CLEANER::filterItem( BOARD_CONNECTED_ITEM* aItem )
{
 if( !m_filter )
 return false;
 
 return (m_filter)( aItem );
}
 
 
void TRACKS_CLEANER::removeShortingTrackSegments()
{
 std::shared_ptr<CONNECTIVITY_DATA> connectivity = m_brd->GetConnectivity();
 
 std::set<BOARD_ITEM *> toRemove;
 
 for( PCB_TRACK* segment : m_brd->Tracks() )
 {
 if( segment->IsLocked() || filterItem( segment ) )
 continue;
 
 for( PAD* testedPad : connectivity->GetConnectedPads( segment ) )
 {
 if( segment->GetNetCode() != testedPad->GetNetCode() )
 {
 std::shared_ptr<CLEANUP_ITEM> item;
 
 if( segment->Type() == PCB_VIA_T )
 item = std::make_shared<CLEANUP_ITEM>( CLEANUP_SHORTING_VIA );
 else
 item = std::make_shared<CLEANUP_ITEM>( CLEANUP_SHORTING_TRACK );
 
 item->SetItems( segment );
 m_itemsList->push_back( item );
 
 toRemove.insert( segment );
 }
 }
 
 for( PCB_TRACK* testedTrack : connectivity->GetConnectedTracks( segment ) )
 {
 if( segment->GetNetCode() != testedTrack->GetNetCode() )
 {
 std::shared_ptr<CLEANUP_ITEM> item;
 
 if( segment->Type() == PCB_VIA_T )
 item = std::make_shared<CLEANUP_ITEM>( CLEANUP_SHORTING_VIA );
 else
 item = std::make_shared<CLEANUP_ITEM>( CLEANUP_SHORTING_TRACK );
 
 item->SetItems( segment );
 m_itemsList->push_back( item );
 
 toRemove.insert( segment );
 }
 }
 }
 
 if( !m_dryRun )
 removeItems( toRemove );
}
 
 
bool TRACKS_CLEANER::testTrackEndpointIsNode( PCB_TRACK* aTrack, bool aTstStart )
{
 // A node is a point where more than 2 items are connected.
 
 const std::list<CN_ITEM*>& items =
 m_brd->GetConnectivity()->GetConnectivityAlgo()->ItemEntry( aTrack ).GetItems();
 
 if( items.empty() )
 return false;
 
 CN_ITEM* citem = items.front();
 
 if( !citem->Valid() )
 return false;
 
 const std::vector<std::shared_ptr<CN_ANCHOR>>& anchors = citem->Anchors();
 
 VECTOR2I refpoint = aTstStart ? aTrack->GetStart() : aTrack->GetEnd();
 
 for( const std::shared_ptr<CN_ANCHOR>& anchor : anchors )
 {
 if( anchor->Pos() != refpoint )
 continue;
 
 // The right anchor point is found: if more than one other item
 // (pad, via, track...) is connected, it is a node:
 return anchor->ConnectedItemsCount() > 1;
 }
 
 return false;
}
 
 
bool TRACKS_CLEANER::deleteDanglingTracks( bool aTrack, bool aVia )
{
 bool item_erased = false;
 bool modified = false;
 
 if( !aTrack && !aVia )
 return false;
 
 do // Iterate when at least one track is deleted
 {
 item_erased = false;
 // Ensure the connectivity is up to date, especially after removing a dangling segment
 m_brd->BuildConnectivity();
 
 // Keep a duplicate deque to all deleting in the primary
 std::deque<PCB_TRACK*> temp_tracks( m_brd->Tracks() );
 
 for( PCB_TRACK* track : temp_tracks )
 {
 if( track->HasFlag( IS_DELETED ) || track->IsLocked() || filterItem( track ) )
 continue;
 
 if( !aVia && track->Type() == PCB_VIA_T )
 continue;
 
 if( !aTrack && ( track->Type() == PCB_TRACE_T || track->Type() == PCB_ARC_T ) )
 continue;
 
 // Test if a track (or a via) endpoint is not connected to another track or zone.
 if( m_brd->GetConnectivity()->TestTrackEndpointDangling( track, false ) )
 {
 std::shared_ptr<CLEANUP_ITEM> item;
 
 if( track->Type() == PCB_VIA_T )
 item = std::make_shared<CLEANUP_ITEM>( CLEANUP_DANGLING_VIA );
 else
 item = std::make_shared<CLEANUP_ITEM>( CLEANUP_DANGLING_TRACK );
 
 item->SetItems( track );
 m_itemsList->push_back( item );
 track->SetFlags( IS_DELETED );
 
 // keep iterating, because a track connected to the deleted track
 // now perhaps is not connected and should be deleted
 item_erased = true;
 
 if( !m_dryRun )
 {
 m_brd->Remove( track );
 m_commit.Removed( track );
 modified = true;
 }
 }
 }
 } while( item_erased ); // A segment was erased: test for some new dangling segments
 
 return modified;
}
 
 
void TRACKS_CLEANER::deleteTracksInPads()
{
 std::set<BOARD_ITEM*> toRemove;
 
 // Delete tracks that start and end on the same pad
 std::shared_ptr<CONNECTIVITY_DATA> connectivity = m_brd->GetConnectivity();
 
 for( PCB_TRACK* track : m_brd->Tracks() )
 {
 if( track->IsLocked() || filterItem( track ) )
 continue;
 
 if( track->Type() == PCB_VIA_T )
 continue;
 
 // Mark track if connected to pads
 for( PAD* pad : connectivity->GetConnectedPads( track ) )
 {
 if( pad->HitTest( track->GetStart() ) && pad->HitTest( track->GetEnd() ) )
 {
 SHAPE_POLY_SET poly;
 track->TransformShapeToPolygon( poly, track->GetLayer(), 0, ARC_HIGH_DEF,
 ERROR_INSIDE );
 
 poly.BooleanSubtract( *pad->GetEffectivePolygon( track->GetLayer(), ERROR_INSIDE ),
 SHAPE_POLY_SET::PM_FAST );
 
 if( poly.IsEmpty() )
 {
 auto item = std::make_shared<CLEANUP_ITEM>( CLEANUP_TRACK_IN_PAD );
 item->SetItems( track );
 m_itemsList->push_back( item );
 
 toRemove.insert( track );
 track->SetFlags( IS_DELETED );
 }
 }
 }
 }
 
 if( !m_dryRun )
 removeItems( toRemove );
}
 
 
void TRACKS_CLEANER::cleanup( bool aDeleteDuplicateVias, bool aDeleteNullSegments,
 bool aDeleteDuplicateSegments, bool aMergeSegments )
{
 DRC_RTREE rtree;
 
 for( PCB_TRACK* track : m_brd->Tracks() )
 {
 track->ClearFlags( IS_DELETED | SKIP_STRUCT );
 rtree.Insert( track, track->GetLayer() );
 }
 
 std::set<BOARD_ITEM*> toRemove;
 
 for( PCB_TRACK* track : m_brd->Tracks() )
 {
 if( track->HasFlag( IS_DELETED ) || track->IsLocked() || filterItem( track ) )
 continue;
 
 if( aDeleteDuplicateVias && track->Type() == PCB_VIA_T )
 {
 PCB_VIA* via = static_cast<PCB_VIA*>( track );
 
 if( via->GetStart() != via->GetEnd() )
 via->SetEnd( via->GetStart() );
 
 rtree.QueryColliding( via, via->GetLayer(), via->GetLayer(),
 // Filter:
 [&]( BOARD_ITEM* aItem ) -> bool
 {
 return aItem->Type() == PCB_VIA_T
 && !aItem->HasFlag( SKIP_STRUCT )
 && !aItem->HasFlag( IS_DELETED );
 },
 // Visitor:
 [&]( BOARD_ITEM* aItem ) -> bool
 {
 PCB_VIA* other = static_cast<PCB_VIA*>( aItem );
 
 if( via->GetPosition() == other->GetPosition()
 && via->GetViaType() == other->GetViaType()
 && via->GetLayerSet() == other->GetLayerSet() )
 {
 auto item = std::make_shared<CLEANUP_ITEM>( CLEANUP_REDUNDANT_VIA );
 item->SetItems( via );
 m_itemsList->push_back( item );
 
 via->SetFlags( IS_DELETED );
 toRemove.insert( via );
 }
 
 return true;
 } );
 
 // To delete through Via on THT pads at same location
 // Examine the list of connected pads: if a through pad is found, the via is redundant
 for( PAD* pad : m_brd->GetConnectivity()->GetConnectedPads( via ) )
 {
 const LSET all_cu = LSET::AllCuMask();
 
 if( ( pad->GetLayerSet() & all_cu ) == all_cu )
 {
 auto item = std::make_shared<CLEANUP_ITEM>( CLEANUP_REDUNDANT_VIA );
 item->SetItems( via, pad );
 m_itemsList->push_back( item );
 
 via->SetFlags( IS_DELETED );
 toRemove.insert( via );
 break;
 }
 }
 
 via->SetFlags( SKIP_STRUCT );
 }
 
 if( aDeleteNullSegments && track->Type() != PCB_VIA_T )
 {
 if( track->IsNull() )
 {
 auto item = std::make_shared<CLEANUP_ITEM>( CLEANUP_ZERO_LENGTH_TRACK );
 item->SetItems( track );
 m_itemsList->push_back( item );
 
 track->SetFlags( IS_DELETED );
 toRemove.insert( track );
 }
 }
 
 if( aDeleteDuplicateSegments && track->Type() == PCB_TRACE_T && !track->IsNull() )
 {
 rtree.QueryColliding( track, track->GetLayer(), track->GetLayer(),
 // Filter:
 [&]( BOARD_ITEM* aItem ) -> bool
 {
 return aItem->Type() == PCB_TRACE_T
 && !aItem->HasFlag( SKIP_STRUCT )
 && !aItem->HasFlag( IS_DELETED )
 && !static_cast<PCB_TRACK*>( aItem )->IsNull();
 },
 // Visitor:
 [&]( BOARD_ITEM* aItem ) -> bool
 {
 PCB_TRACK* other = static_cast<PCB_TRACK*>( aItem );
 
 if( track->IsPointOnEnds( other->GetStart() )
 && track->IsPointOnEnds( other->GetEnd() )
 && track->GetWidth() == other->GetWidth()
 && track->GetLayer() == other->GetLayer() )
 {
 auto item = std::make_shared<CLEANUP_ITEM>( CLEANUP_DUPLICATE_TRACK );
 item->SetItems( track );
 m_itemsList->push_back( item );
 
 track->SetFlags( IS_DELETED );
 toRemove.insert( track );
 }
 
 return true;
 } );
 
 track->SetFlags( SKIP_STRUCT );
 }
 }
 
 if( !m_dryRun )
 removeItems( toRemove );
 
 auto mergeSegments =
 [&]( std::shared_ptr<CN_CONNECTIVITY_ALGO> connectivity ) -> bool
 {
 for( PCB_TRACK* segment : m_brd->Tracks() )
 {
 // one can merge only collinear segments, not vias or arcs.
 if( segment->Type() != PCB_TRACE_T )
 continue;
 
 if( segment->HasFlag( IS_DELETED ) ) // already taken into account
 continue;
 
 if( filterItem( segment ) )
 continue;
 
 // for each end of the segment:
 for( CN_ITEM* citem : connectivity->ItemEntry( segment ).GetItems() )
 {
 // Do not merge an end which has different width tracks attached -- it's a
 // common use-case for necking-down a track between pads.
 std::vector<PCB_TRACK*> sameWidthCandidates;
 std::vector<PCB_TRACK*> differentWidthCandidates;
 
 for( CN_ITEM* connected : citem->ConnectedItems() )
 {
 if( !connected->Valid() )
 continue;
 
 BOARD_CONNECTED_ITEM* candidate = connected->Parent();
 
 if( candidate->Type() == PCB_TRACE_T
 && !candidate->HasFlag( IS_DELETED )
 && !filterItem( candidate ) )
 {
 PCB_TRACK* candidateSegment = static_cast<PCB_TRACK*>( candidate );
 
 if( candidateSegment->GetWidth() == segment->GetWidth() )
 {
 sameWidthCandidates.push_back( candidateSegment );
 }
 else
 {
 differentWidthCandidates.push_back( candidateSegment );
 break;
 }
 }
 }
 
 if( !differentWidthCandidates.empty() )
 continue;
 
 for( PCB_TRACK* candidate : sameWidthCandidates )
 {
 if( segment->ApproxCollinear( *candidate )
 && mergeCollinearSegments( segment, candidate ) )
 {
 return true;
 }
 }
 }
 }
 
 return false;
 };
 
 if( aMergeSegments )
 {
 do
 {
 while( !m_brd->BuildConnectivity() )
 wxSafeYield();
 
 m_connectedItemsCache.clear();
 } while( mergeSegments( m_brd->GetConnectivity()->GetConnectivityAlgo() ) );
 }
 
 for( PCB_TRACK* track : m_brd->Tracks() )
 track->ClearFlags( IS_DELETED | SKIP_STRUCT );
}
 
 
const std::vector<BOARD_CONNECTED_ITEM*>& TRACKS_CLEANER::getConnectedItems( PCB_TRACK* aTrack )
{
 static const std::vector<KICAD_T> connectedTypes = { PCB_TRACE_T,
 PCB_ARC_T,
 PCB_VIA_T,
 PCB_PAD_T,
 PCB_ZONE_T };
 
 const std::shared_ptr<CONNECTIVITY_DATA>& connectivity = m_brd->GetConnectivity();
 
 if( m_connectedItemsCache.count( aTrack ) == 0 )
 m_connectedItemsCache[ aTrack ] = connectivity->GetConnectedItems( aTrack, connectedTypes );
 
 return m_connectedItemsCache[ aTrack ];
}
 
 
bool TRACKS_CLEANER::mergeCollinearSegments( PCB_TRACK* aSeg1, PCB_TRACK* aSeg2 )
{
 if( aSeg1->IsLocked() || aSeg2->IsLocked() )
 return false;
 
 // Collect the unique points where the two tracks are connected to other items
 std::set<VECTOR2I> pts;
 
 auto collectPts =
 [&]( BOARD_CONNECTED_ITEM* citem )
 {
 if( citem->Type() == PCB_TRACE_T || citem->Type() == PCB_ARC_T
 || citem->Type() == PCB_VIA_T )
 {
 PCB_TRACK* track = static_cast<PCB_TRACK*>( citem );
 
 if( track->IsPointOnEnds( aSeg1->GetStart() ) )
 pts.emplace( aSeg1->GetStart() );
 
 if( track->IsPointOnEnds( aSeg1->GetEnd() ) )
 pts.emplace( aSeg1->GetEnd() );
 
 if( track->IsPointOnEnds( aSeg2->GetStart() ) )
 pts.emplace( aSeg2->GetStart() );
 
 if( track->IsPointOnEnds( aSeg2->GetEnd() ) )
 pts.emplace( aSeg2->GetEnd() );
 }
 else
 {
 if( citem->HitTest( aSeg1->GetStart(), ( aSeg1->GetWidth() + 1 ) / 2 ) )
 pts.emplace( aSeg1->GetStart() );
 
 if( citem->HitTest( aSeg1->GetEnd(), ( aSeg1->GetWidth() + 1 ) / 2 ) )
 pts.emplace( aSeg1->GetEnd() );
 
 if( citem->HitTest( aSeg2->GetStart(), ( aSeg2->GetWidth() + 1 ) / 2 ) )
 pts.emplace( aSeg2->GetStart() );
 
 if( citem->HitTest( aSeg2->GetEnd(), ( aSeg2->GetWidth() + 1 ) / 2 ) )
 pts.emplace( aSeg2->GetEnd() );
 }
 };
 
 for( BOARD_CONNECTED_ITEM* item : getConnectedItems( aSeg1 ) )
 {
 if( item != aSeg1 && item != aSeg2 )
 collectPts( item );
 }
 
 for( BOARD_CONNECTED_ITEM* item : getConnectedItems( aSeg2 ) )
 {
 if( item != aSeg1 && item != aSeg2 )
 collectPts( item );
 }
 
 // This means there is a node in the center
 if( pts.size() > 2 )
 return false;
 
 // Verify the removed point after merging is not a node.
 // If it is a node (i.e. if more than one other item is connected, the segments cannot be merged
 PCB_TRACK dummy_seg( *aSeg1 );
 
 // Calculate the new ends of the segment to merge, and store them to dummy_seg:
 int min_x = std::min( aSeg1->GetStart().x,
 std::min( aSeg1->GetEnd().x, std::min( aSeg2->GetStart().x, aSeg2->GetEnd().x ) ) );
 int min_y = std::min( aSeg1->GetStart().y,
 std::min( aSeg1->GetEnd().y, std::min( aSeg2->GetStart().y, aSeg2->GetEnd().y ) ) );
 int max_x = std::max( aSeg1->GetStart().x,
 std::max( aSeg1->GetEnd().x, std::max( aSeg2->GetStart().x, aSeg2->GetEnd().x ) ) );
 int max_y = std::max( aSeg1->GetStart().y,
 std::max( aSeg1->GetEnd().y, std::max( aSeg2->GetStart().y, aSeg2->GetEnd().y ) ) );
 
 if( ( aSeg1->GetStart().x > aSeg1->GetEnd().x )
 == ( aSeg1->GetStart().y > aSeg1->GetEnd().y ) )
 {
 dummy_seg.SetStart( VECTOR2I( min_x, min_y ) );
 dummy_seg.SetEnd( VECTOR2I( max_x, max_y ) );
 }
 else
 {
 dummy_seg.SetStart( VECTOR2I( min_x, max_y ) );
 dummy_seg.SetEnd( VECTOR2I( max_x, min_y ) );
 }
 
 // The new ends of the segment must be connected to all of the same points as the original
 // segments. If not, the segments cannot be merged.
 for( auto& pt : pts )
 {
 if( !dummy_seg.IsPointOnEnds( pt ) )
 {
 dummy_seg.SetParentGroup( nullptr );
 return false;
 }
 }
 
 // Now find the removed end(s) and stop merging if it is a node:
 if( aSeg1->GetStart() != dummy_seg.GetStart() && aSeg1->GetStart() != dummy_seg.GetEnd() )
 {
 if( testTrackEndpointIsNode( aSeg1, true ) )
 {
 dummy_seg.SetParentGroup( nullptr );
 return false;
 }
 }
 
 if( aSeg1->GetEnd() != dummy_seg.GetStart() && aSeg1->GetEnd() != dummy_seg.GetEnd() )
 {
 if( testTrackEndpointIsNode( aSeg1, false ) )
 {
 dummy_seg.SetParentGroup( nullptr );
 return false;
 }
 }
 
 std::shared_ptr<CLEANUP_ITEM> item = std::make_shared<CLEANUP_ITEM>( CLEANUP_MERGE_TRACKS );
 item->SetItems( aSeg1, aSeg2 );
 m_itemsList->push_back( item );
 
 aSeg2->SetFlags( IS_DELETED );
 
 if( !m_dryRun )
 {
 m_commit.Modify( aSeg1 );
 *aSeg1 = dummy_seg;
 
 m_brd->GetConnectivity()->Update( aSeg1 );
 
 // Merge successful, seg2 has to go away
 m_brd->Remove( aSeg2 );
 m_commit.Removed( aSeg2 );
 }
 
 // Note that dummy_seg is used to replace aSeg1 after processing, so the group membership must
 // be kept until all processing has finished, and cannot be removed right after creation of the
 // dummy object
 dummy_seg.SetParentGroup( nullptr );
 return true;
}
 
 
void TRACKS_CLEANER::removeItems( std::set<BOARD_ITEM*>& aItems )
{
 for( BOARD_ITEM* item : aItems )
 {
 m_brd->Remove( item );
 m_commit.Removed( item );
 }
}