pns_router.cpp

Go to the documentation of this file.

/*
 * KiRouter - a push-and-(sometimes-)shove PCB router
 *
 * Copyright (C) 2013-2014 CERN
 * Copyright (C) 2016-2023 KiCad Developers, see AUTHORS.txt for contributors.
 * Author: Tomasz Wlostowski <[email protected]>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */
 
#include <cstdio>
#include <memory>
#include <vector>
 
#include <view/view.h>
#include <view/view_group.h>
#include <gal/graphics_abstraction_layer.h>
 
#include <advanced_config.h>
#include <settings/settings_manager.h>
 
#include <pcb_painter.h>
#include <pcbnew_settings.h>
#include <pad.h>
#include <zone.h>
 
#include <geometry/shape.h>
 
#include "pns_node.h"
#include "pns_line_placer.h"
#include "pns_line.h"
#include "pns_solid.h"
#include "pns_utils.h"
#include "pns_router.h"
#include "pns_shove.h"
#include "pns_dragger.h"
#include "pns_component_dragger.h"
#include "pns_topology.h"
#include "pns_diff_pair_placer.h"
#include "pns_meander_placer.h"
#include "pns_meander_skew_placer.h"
#include "pns_dp_meander_placer.h"
 
namespace PNS {
 
// an ugly singleton for drawing debug items within the router context.
// To be fixed sometime in the future.
static ROUTER* theRouter;
 
ROUTER::ROUTER()
{
 theRouter = this;
 
 m_state = IDLE;
 m_mode = PNS_MODE_ROUTE_SINGLE;
 
 m_logger = nullptr;
 
 if( ADVANCED_CFG::GetCfg().m_EnableRouterDump )
 m_logger = new LOGGER;
 
 // Initialize all other variables:
 m_lastNode = nullptr;
 m_iterLimit = 0;
 m_settings = nullptr;
 m_iface = nullptr;
 m_visibleViewArea.SetMaximum();
}
 
 
ROUTER* ROUTER::GetInstance()
{
 return theRouter;
}
 
 
ROUTER::~ROUTER()
{
 ClearWorld();
 theRouter = nullptr;
 delete m_logger;
}
 
 
void ROUTER::SyncWorld()
{
 ClearWorld();
 
 m_world = std::make_unique<NODE>( );
 m_iface->SyncWorld( m_world.get() );
 m_world->FixupVirtualVias();
}
 
 
void ROUTER::ClearWorld()
{
 if( m_world )
 {
 m_world->SetRuleResolver( nullptr );
 m_world->KillChildren();
 m_world.reset();
 }
 
 m_placer.reset();
}
 
 
bool ROUTER::RoutingInProgress() const
{
 return m_state != IDLE;
}
 
 
const ITEM_SET ROUTER::QueryHoverItems( const VECTOR2I& aP, bool aUseClearance )
{
 NODE* node = nullptr;
 int clearance = 0;
 
 if( m_state == IDLE || m_placer == nullptr )
 {
 node = m_world.get();
 clearance = 0;
 }
 else if( m_mode == PNS_MODE_ROUTE_SINGLE )
 {
 node = m_placer->CurrentNode();
 clearance = m_sizes.Clearance() + m_sizes.TrackWidth() / 2;
 }
 else if( m_mode == PNS_MODE_ROUTE_DIFF_PAIR )
 {
 node = m_placer->CurrentNode();
 clearance = m_sizes.Clearance() + m_sizes.DiffPairWidth() / 2;
 }
 
 if( aUseClearance )
 {
 NODE::OBSTACLES obs;
 SEGMENT test( SEG( aP, aP ), nullptr );
 COLLISION_SEARCH_OPTIONS opts;
 
 test.SetWidth( 1 );
 test.SetLayers( LAYER_RANGE::All() );
 
 opts.m_differentNetsOnly = false;
 opts.m_overrideClearance = clearance;
 
 PNS::ITEM_SET ret;
 
 wxCHECK( node, ret );
 
 node->QueryColliding( &test, obs, opts );
 
 for( const OBSTACLE& obstacle : obs )
 ret.Add( obstacle.m_item, false );
 
 return ret;
 }
 else
 {
 return node->HitTest( aP );
 }
}
 
 
bool ROUTER::StartDragging( const VECTOR2I& aP, ITEM* aItem, int aDragMode )
{
 return StartDragging( aP, ITEM_SET( aItem ), aDragMode );
}
 
 
bool ROUTER::StartDragging( const VECTOR2I& aP, ITEM_SET aStartItems, int aDragMode )
{
 if( aStartItems.Empty() )
 return false;
 
 GetRuleResolver()->ClearCaches();
 
 if( aStartItems.Count( ITEM::SOLID_T ) == aStartItems.Size() )
 {
 m_dragger = std::make_unique<COMPONENT_DRAGGER>( this );
 m_forceMarkObstaclesMode = true;
 m_state = DRAG_COMPONENT;
 }
 else
 {
 if( aDragMode & DM_FREE_ANGLE )
 m_forceMarkObstaclesMode = true;
 else
 m_forceMarkObstaclesMode = false;
 
 m_dragger = std::make_unique<DRAGGER>( this );
 m_state = DRAG_SEGMENT;
 }
 
 m_dragger->SetMode( static_cast<PNS::DRAG_MODE>( aDragMode ) );
 m_dragger->SetWorld( m_world.get() );
 m_dragger->SetLogger( m_logger );
 m_dragger->SetDebugDecorator( m_iface->GetDebugDecorator() );
 
 if( m_logger )
 m_logger->Clear();
 
 if( m_logger && aStartItems.Size() )
 m_logger->Log( LOGGER::EVT_START_DRAG, aP, aStartItems[0] );
 
 if( m_dragger->Start( aP, aStartItems ) )
 {
 return true;
 }
 else
 {
 m_dragger.reset();
 m_state = IDLE;
 return false;
 }
}
 
 
bool ROUTER::isStartingPointRoutable( const VECTOR2I& aWhere, ITEM* aStartItem, int aLayer )
{
 if( Settings().AllowDRCViolations() )
 return true;
 
 if( m_mode == PNS_MODE_ROUTE_DIFF_PAIR )
 {
 if( m_sizes.DiffPairGap() < m_sizes.MinClearance() )
 {
 SetFailureReason( _( "Diff pair gap is less than board minimum clearance." ) );
 return false;
 }
 }
 
 ITEM_SET candidates = QueryHoverItems( aWhere );
 wxString failureReason;
 
 for( ITEM* item : candidates.Items() )
 {
 // Edge cuts are put on all layers, but they're not *really* on all layers
 if( item->BoardItem() && item->BoardItem()->GetLayer() == Edge_Cuts )
 continue;
 
 if( !item->Layers().Overlaps( aLayer ) )
 continue;
 
 if( item->IsRoutable() )
 {
 failureReason = wxEmptyString;
 break;
 }
 else
 {
 BOARD_ITEM* parent = item->BoardItem();
 
 switch( parent->Type() )
 {
 case PCB_PAD_T:
 {
 PAD* pad = static_cast<PAD*>( parent );
 
 if( pad->GetAttribute() == PAD_ATTRIB::NPTH )
 failureReason = _( "Cannot start routing from a non-plated hole." );
 }
 break;
 
 case PCB_ZONE_T:
 {
 ZONE* zone = static_cast<ZONE*>( parent );
 
 if( !zone->GetZoneName().IsEmpty() )
 {
 failureReason = wxString::Format( _( "Rule area '%s' disallows tracks." ),
 zone->GetZoneName() );
 }
 else
 {
 failureReason = _( "Rule area disallows tracks." );
 }
 }
 break;
 
 case PCB_FIELD_T:
 case PCB_TEXT_T:
 case PCB_TEXTBOX_T:
 failureReason = _( "Cannot start routing from a text item." );
 break;
 
 default:
 break;
 }
 }
 }
 
 if( !failureReason.IsEmpty() )
 {
 SetFailureReason( failureReason );
 return false;
 }
 
 VECTOR2I startPoint = aWhere;
 
 if( m_mode == PNS_MODE_ROUTE_SINGLE )
 {
 SHAPE_LINE_CHAIN dummyStartSeg;
 LINE dummyStartLine;
 
 dummyStartSeg.Append( startPoint );
 dummyStartSeg.Append( startPoint, true );
 
 dummyStartLine.SetShape( dummyStartSeg );
 dummyStartLine.SetLayer( aLayer );
 dummyStartLine.SetNet( aStartItem ? aStartItem->Net() : 0 );
 dummyStartLine.SetWidth( m_sizes.TrackWidth() );
 
 if( m_world->CheckColliding( &dummyStartLine, ITEM::ANY_T ) )
 {
 // If the only reason we collide is track width; it's better to allow the user to start
 // anyway and just highlight the resulting collisions, so they can change width later.
 dummyStartLine.SetWidth( m_sizes.BoardMinTrackWidth() );
 
 if( m_world->CheckColliding( &dummyStartLine, ITEM::ANY_T ) )
 {
 ITEM_SET dummyStartSet( &dummyStartLine );
 NODE::ITEM_VECTOR highlightedItems;
 
 markViolations( m_world.get(), dummyStartSet, highlightedItems );
 
 for( ITEM* item : highlightedItems )
 m_iface->HideItem( item );
 
 SetFailureReason( _( "The routing start point violates DRC." ) );
 return false;
 }
 }
 }
 else if( m_mode == PNS_MODE_ROUTE_DIFF_PAIR )
 {
 if( !aStartItem )
 {
 SetFailureReason( _( "Cannot start a differential pair in the middle of nowhere." ) );
 return false;
 }
 
 DP_PRIMITIVE_PAIR dpPair;
 wxString errorMsg;
 
 if( !DIFF_PAIR_PLACER::FindDpPrimitivePair( m_world.get(), startPoint, aStartItem, dpPair,
 &errorMsg ) )
 {
 SetFailureReason( errorMsg );
 return false;
 }
 
 SHAPE_LINE_CHAIN dummyStartSegA;
 SHAPE_LINE_CHAIN dummyStartSegB;
 LINE dummyStartLineA;
 LINE dummyStartLineB;
 
 dummyStartSegA.Append( dpPair.AnchorN() );
 dummyStartSegA.Append( dpPair.AnchorN(), true );
 
 dummyStartSegB.Append( dpPair.AnchorP() );
 dummyStartSegB.Append( dpPair.AnchorP(), true );
 
 dummyStartLineA.SetShape( dummyStartSegA );
 dummyStartLineA.SetLayer( aLayer );
 dummyStartLineA.SetNet( dpPair.PrimN()->Net() );
 dummyStartLineA.SetWidth( m_sizes.DiffPairWidth() );
 
 dummyStartLineB.SetShape( dummyStartSegB );
 dummyStartLineB.SetLayer( aLayer );
 dummyStartLineB.SetNet( dpPair.PrimP()->Net() );
 dummyStartLineB.SetWidth( m_sizes.DiffPairWidth() );
 
 if( m_world->CheckColliding( &dummyStartLineA, ITEM::ANY_T )
 || m_world->CheckColliding( &dummyStartLineB, ITEM::ANY_T ) )
 {
 // If the only reason we collide is track width; it's better to allow the user to start
 // anyway and just highlight the resulting collisions, so they can change width later.
 dummyStartLineA.SetWidth( m_sizes.BoardMinTrackWidth() );
 dummyStartLineB.SetWidth( m_sizes.BoardMinTrackWidth() );
 
 if( m_world->CheckColliding( &dummyStartLineA, ITEM::ANY_T )
 || m_world->CheckColliding( &dummyStartLineB, ITEM::ANY_T ) )
 {
 ITEM_SET dummyStartSet;
 NODE::ITEM_VECTOR highlightedItems;
 
 dummyStartSet.Add( dummyStartLineA );
 dummyStartSet.Add( dummyStartLineB );
 markViolations( m_world.get(), dummyStartSet, highlightedItems );
 
 for( ITEM* item : highlightedItems )
 m_iface->HideItem( item );
 
 SetFailureReason( _( "The routing start point violates DRC." ) );
 return false;
 }
 }
 }
 
 return true;
}
 
 
bool ROUTER::StartRouting( const VECTOR2I& aP, ITEM* aStartItem, int aLayer )
{
 GetRuleResolver()->ClearCaches();
 
 if( !isStartingPointRoutable( aP, aStartItem, aLayer ) )
 return false;
 
 m_forceMarkObstaclesMode = false;
 
 switch( m_mode )
 {
 case PNS_MODE_ROUTE_SINGLE:
 m_placer = std::make_unique<LINE_PLACER>( this );
 break;
 
 case PNS_MODE_ROUTE_DIFF_PAIR:
 m_placer = std::make_unique<DIFF_PAIR_PLACER>( this );
 break;
 
 case PNS_MODE_TUNE_SINGLE:
 m_placer = std::make_unique<MEANDER_PLACER>( this );
 break;
 
 case PNS_MODE_TUNE_DIFF_PAIR:
 m_placer = std::make_unique<DP_MEANDER_PLACER>( this );
 break;
 
 case PNS_MODE_TUNE_DIFF_PAIR_SKEW:
 m_placer = std::make_unique<MEANDER_SKEW_PLACER>( this );
 break;
 
 default:
 return false;
 }
 
 m_placer->UpdateSizes( m_sizes );
 m_placer->SetLayer( aLayer );
 m_placer->SetDebugDecorator( m_iface->GetDebugDecorator() );
 m_placer->SetLogger( m_logger );
 
 if( m_placer->Start( aP, aStartItem ) )
 {
 m_state = ROUTE_TRACK;
 
 if( m_logger )
 {
 m_logger->Clear();
 m_logger->Log( LOGGER::EVT_START_ROUTE, aP, aStartItem, &m_sizes );
 }
 
 return true;
 }
 else
 {
 m_state = IDLE;
 return false;
 }
}
 
 
bool ROUTER::Move( const VECTOR2I& aP, ITEM* endItem )
{
 if( m_logger )
 m_logger->Log( LOGGER::EVT_MOVE, aP, endItem );
 
 switch( m_state )
 {
 case ROUTE_TRACK:
 return movePlacing( aP, endItem );
 
 case DRAG_SEGMENT:
 case DRAG_COMPONENT:
 return moveDragging( aP, endItem );
 
 default:
 break;
 }
 
 return false;
}
 
 
bool ROUTER::getNearestRatnestAnchor( VECTOR2I& aOtherEnd, LAYER_RANGE& aOtherEndLayers,
 ITEM*& aOtherEndItem )
{
 // Can't finish something with no connections
 if( GetCurrentNets().empty() )
 return false;
 
 PLACEMENT_ALGO* placer = Placer();
 
 if( placer == nullptr || placer->Traces().Size() == 0 )
 return false;
 
 LINE* trace = dynamic_cast<LINE*>( placer->Traces()[0] );
 
 if( trace == nullptr )
 return false;
 
 PNS::NODE* lastNode = placer->CurrentNode( true );
 PNS::TOPOLOGY topo( lastNode );
 
 // If the user has drawn a line, get the anchor nearest to the line end
 if( trace->SegmentCount() > 0 )
 {
 return topo.NearestUnconnectedAnchorPoint( trace, aOtherEnd, aOtherEndLayers,
 aOtherEndItem );
 }
 
 // Otherwise, find the closest anchor to our start point
 
 // Get joint from placer start item
 const JOINT* jt = lastNode->FindJoint( placer->CurrentStart(), placer->CurrentLayer(),
 placer->CurrentNets()[0] );
 
 if( !jt )
 return false;
 
 // Get unconnected item from joint
 int anchor;
 PNS::ITEM* it = topo.NearestUnconnectedItem( jt, &anchor );
 
 if( !it )
 return false;
 
 aOtherEnd = it->Anchor( anchor );
 aOtherEndLayers = it->Layers();
 aOtherEndItem = it;
 
 return true;
}
 
 
bool ROUTER::Finish()
{
 if( m_state != ROUTE_TRACK )
 return false;
 
 PLACEMENT_ALGO* placer = Placer();
 
 if( placer == nullptr || placer->Traces().Size() == 0 )
 return false;
 
 LINE* current = dynamic_cast<LINE*>( placer->Traces()[0] );
 
 if( current == nullptr )
 return false;
 
 // Get our current line and position and nearest ratsnest to them if it exists
 VECTOR2I otherEnd;
 LAYER_RANGE otherEndLayers;
 ITEM* otherEndItem = nullptr;
 
 // Get the anchor nearest to the end of the trace the user is routing
 if( !getNearestRatnestAnchor( otherEnd, otherEndLayers, otherEndItem ) )
 return false;
 
 // Keep moving until we don't change position or hit the limit
 int triesLeft = 5;
 VECTOR2I moveResultPoint;
 
 do
 {
 moveResultPoint = placer->CurrentEnd();
 Move( otherEnd, otherEndItem );
 triesLeft--;
 } while( placer->CurrentEnd() != moveResultPoint && triesLeft );
 
 // If we've made it, fix the route and we're done
 if( moveResultPoint == otherEnd && otherEndLayers.Overlaps( GetCurrentLayer() ) )
 return FixRoute( otherEnd, otherEndItem, false );
 
 return false;
}
 
 
bool ROUTER::ContinueFromEnd()
{
 PLACEMENT_ALGO* placer = Placer();
 
 if( placer == nullptr || placer->Traces().Size() == 0 )
 return false;
 
 LINE* current = dynamic_cast<LINE*>( placer->Traces()[0] );
 
 if( current == nullptr )
 return false;
 
 int currentLayer = GetCurrentLayer();
 VECTOR2I currentEnd = placer->CurrentEnd();
 VECTOR2I otherEnd;
 LAYER_RANGE otherEndLayers;
 ITEM* otherEndItem = nullptr;
 
 // Get the anchor nearest to the end of the trace the user is routing
 if( !getNearestRatnestAnchor( otherEnd, otherEndLayers, otherEndItem ) )
 return false;
 
 CommitRouting();
 
 // Commit whatever we've fixed and restart routing from the other end
 int nextLayer = otherEndLayers.Overlaps( currentLayer ) ? currentLayer : otherEndLayers.Start();
 
 if( !StartRouting( otherEnd, otherEndItem, nextLayer ) )
 return false;
 
 // Attempt to route to our current position
 Move( currentEnd, current );
 
 return true;
}
 
 
bool ROUTER::moveDragging( const VECTOR2I& aP, ITEM* aEndItem )
{
 m_iface->EraseView();
 
 bool ret = m_dragger->Drag( aP );
 ITEM_SET dragged = m_dragger->Traces();
 
 updateView( m_dragger->CurrentNode(), dragged, true );
 return ret;
}
 
 
void ROUTER::markViolations( NODE* aNode, ITEM_SET& aCurrent, NODE::ITEM_VECTOR& aRemoved )
{
 auto updateItem =
 [&]( ITEM* currentItem, ITEM* itemToMark )
 {
 std::unique_ptr<ITEM> tmp( itemToMark->Clone() );
 
 int clearance;
 bool removeOriginal = true;
 
 clearance = aNode->GetClearance( currentItem, itemToMark );
 
 if( itemToMark->Layers().IsMultilayer() && !currentItem->Layers().IsMultilayer() )
 tmp->SetLayer( currentItem->Layer() );
 
 if( itemToMark->IsCompoundShapePrimitive() )
 {
 // We're only highlighting one (or more) of several primitives so we don't
 // want all the other parts of the object to disappear
 removeOriginal = false;
 }
 
 m_iface->DisplayItem( tmp.get(), clearance );
 
 if( removeOriginal )
 aRemoved.push_back( itemToMark );
 };
 
 for( ITEM* item : aCurrent.Items() )
 {
 NODE::OBSTACLES obstacles;
 
 aNode->QueryColliding( item, obstacles );
 
 if( item->OfKind( ITEM::LINE_T ) )
 {
 LINE* l = static_cast<LINE*>( item );
 
 if( l->EndsWithVia() )
 {
 VIA v( l->Via() );
 aNode->QueryColliding( &v, obstacles );
 }
 }
 
 ITEM_SET draggedItems;
 
 if( GetDragger() )
 draggedItems = GetDragger()->Traces();
 
 for( const OBSTACLE& obs : obstacles )
 {
 // Don't mark items being dragged; only board items they collide with
 if( draggedItems.Contains( obs.m_item ) )
 continue;
 
 obs.m_item->Mark( obs.m_item->Marker() | MK_VIOLATION );
 updateItem( item, obs.m_item );
 }
 
 if( item->Kind() == ITEM::LINE_T )
 {
 LINE* line = static_cast<LINE*>( item );
 
 // Show clearance on any blocking obstacles
 if( line->GetBlockingObstacle() )
 updateItem( item, line->GetBlockingObstacle() );
 }
 }
}
 
 
void ROUTER::updateView( NODE* aNode, ITEM_SET& aCurrent, bool aDragging )
{
 NODE::ITEM_VECTOR removed, added;
 NODE::OBSTACLES obstacles;
 
 if( !aNode )
 return;
 
 markViolations( aNode, aCurrent, removed );
 
 aNode->GetUpdatedItems( removed, added );
 
 std::vector<const PNS::ITEM*> cacheCheckItems( added.begin(), added.end() );
 GetRuleResolver()->ClearCacheForItems( cacheCheckItems );
 
 for( ITEM* item : added )
 {
 int clearance = GetRuleResolver()->Clearance( item, nullptr );
 m_iface->DisplayItem( item, clearance, aDragging );
 }
 
 for( ITEM* item : removed )
 m_iface->HideItem( item );
}
 
 
void ROUTER::UpdateSizes( const SIZES_SETTINGS& aSizes )
{
 m_sizes = aSizes;
 
 // Change track/via size settings
 if( m_state == ROUTE_TRACK )
 m_placer->UpdateSizes( m_sizes );
}
 
 
bool ROUTER::movePlacing( const VECTOR2I& aP, ITEM* aEndItem )
{
 m_iface->EraseView();
 
 bool ret = m_placer->Move( aP, aEndItem );
 ITEM_SET current = m_placer->Traces();
 
 for( const ITEM* item : current.CItems() )
 {
 if( !item->OfKind( ITEM::LINE_T ) )
 continue;
 
 const LINE* l = static_cast<const LINE*>( item );
 int clearance = GetRuleResolver()->Clearance( item, nullptr );
 
 m_iface->DisplayItem( l, clearance, false, true );
 
 if( l->EndsWithVia() )
 {
 const VIA& via = l->Via();
 clearance = GetRuleResolver()->Clearance( &via, nullptr );
 
 if( via.HasHole() )
 {
 int holeClearance = GetRuleResolver()->Clearance( via.Hole(), nullptr );
 int annularWidth = std::max( 0, via.Diameter() - via.Drill() ) / 2;
 int excessHoleClearance = holeClearance - annularWidth;
 
 if( excessHoleClearance > clearance )
 clearance = excessHoleClearance;
 }
 
 m_iface->DisplayItem( &l->Via(), clearance, false, true );
 }
 }
 
 //ITEM_SET tmp( &current );
 
 updateView( m_placer->CurrentNode( true ), current );
 
 return ret;
}
 
 
void ROUTER::GetUpdatedItems( std::vector<PNS::ITEM*>& aRemoved, std::vector<PNS::ITEM*>& aAdded,
 std::vector<PNS::ITEM*>& aHeads )
{
 NODE *node = nullptr;
 ITEM_SET current;
 
 if( m_state == ROUTE_TRACK )
 {
 node = m_placer->CurrentNode( true );
 current = m_placer->Traces();
 }
 else if ( m_state == DRAG_SEGMENT )
 {
 node = m_dragger->CurrentNode();
 current = m_dragger->Traces();
 }
 
 // There probably should be a debugging assertion and possibly a PNS_LOGGER call here but
 // I'm not sure how to be proceed WLS.
 if( !node )
 return;
 
 node->GetUpdatedItems( aRemoved, aAdded );
 
 for( const ITEM* item : current.CItems() )
 aHeads.push_back( item->Clone() );
}
 
 
void ROUTER::CommitRouting( NODE* aNode )
{
 if( m_state == ROUTE_TRACK && !m_placer->HasPlacedAnything() )
 return;
 
 NODE::ITEM_VECTOR removed;
 NODE::ITEM_VECTOR added;
 NODE::ITEM_VECTOR changed;
 
 aNode->GetUpdatedItems( removed, added );
 
 for( ITEM* item : removed )
 {
 bool is_changed = false;
 
 // Items in remove/add that share the same parent are just updated versions
 // We move them to the updated vector to preserve attributes such as UUID and pad data
 if( item->Parent() )
 {
 for( NODE::ITEM_VECTOR::iterator added_it = added.begin();
 added_it != added.end(); ++added_it )
 {
 if( ( *added_it )->Parent() && ( *added_it )->Parent() == item->Parent() )
 {
 changed.push_back( *added_it );
 added.erase( added_it );
 is_changed = true;
 break;
 }
 }
 }
 
 if( !is_changed && !item->IsVirtual() )
 m_iface->RemoveItem( item );
 }
 
 for( ITEM* item : added )
 {
 if( !item->IsVirtual() )
 m_iface->AddItem( item );
 }
 
 for( ITEM* item : changed )
 {
 if( !item->IsVirtual() )
 m_iface->UpdateItem( item );
 }
 
 m_iface->Commit();
 m_world->Commit( aNode );
}
 
 
bool ROUTER::FixRoute( const VECTOR2I& aP, ITEM* aEndItem, bool aForceFinish )
{
 bool rv = false;
 
 if( m_logger )
 m_logger->Log( LOGGER::EVT_FIX, aP, aEndItem );
 
 switch( m_state )
 {
 case ROUTE_TRACK:
 rv = m_placer->FixRoute( aP, aEndItem, aForceFinish );
 break;
 
 case DRAG_SEGMENT:
 case DRAG_COMPONENT:
 rv = m_dragger->FixRoute();
 break;
 
 default:
 break;
 }
 
 return rv;
}
 
 
std::optional<VECTOR2I> ROUTER::UndoLastSegment()
{
 if( !RoutingInProgress() )
 return std::nullopt;
 
 if( m_logger )
 m_logger->Log( LOGGER::EVT_UNFIX );
 
 return m_placer->UnfixRoute();
}
 
 
void ROUTER::CommitRouting()
{
 if( m_state == ROUTE_TRACK )
 m_placer->CommitPlacement();
 
 StopRouting();
}
 
 
void ROUTER::StopRouting()
{
 // Update the ratsnest with new changes
 
 if( m_placer )
 {
 std::vector<NET_HANDLE> nets;
 m_placer->GetModifiedNets( nets );
 
 // Update the ratsnest with new changes
 for( NET_HANDLE n : nets )
 m_iface->UpdateNet( n );
 }
 
 if( !RoutingInProgress() )
 return;
 
 m_placer.reset();
 m_dragger.reset();
 
 m_iface->EraseView();
 
 m_state = IDLE;
 m_world->KillChildren();
 m_world->ClearRanks();
}
 
 
void ROUTER::ClearViewDecorations()
{
 m_iface->EraseView();
}
 
 
void ROUTER::FlipPosture()
{
 if( m_state == ROUTE_TRACK )
 {
 m_placer->FlipPosture();
 }
}
 
 
bool ROUTER::SwitchLayer( int aLayer )
{
 if( m_state == ROUTE_TRACK )
 return m_placer->SetLayer( aLayer );
 
 return false;
}
 
 
void ROUTER::ToggleViaPlacement()
{
 if( m_state == ROUTE_TRACK )
 {
 bool toggle = !m_placer->IsPlacingVia();
 m_placer->ToggleVia( toggle );
 
 if( m_logger )
 m_logger->Log( LOGGER::EVT_TOGGLE_VIA, VECTOR2I(), nullptr, &m_sizes );
 }
}
 
 
const std::vector<NET_HANDLE> ROUTER::GetCurrentNets() const
{
 if( m_placer )
 return m_placer->CurrentNets();
 else if( m_dragger )
 return m_dragger->CurrentNets();
 
 return std::vector<NET_HANDLE>();
}
 
 
int ROUTER::GetCurrentLayer() const
{
 if( m_placer )
 return m_placer->CurrentLayer();
 else if( m_dragger )
 return m_dragger->CurrentLayer();
 
 return -1;
}
 
 
LOGGER* ROUTER::Logger()
{
 return m_logger;
}
 
 
bool ROUTER::IsPlacingVia() const
{
 if( !m_placer )
 return false;
 
 return m_placer->IsPlacingVia();
}
 
 
void ROUTER::ToggleCornerMode()
{
 DIRECTION_45::CORNER_MODE mode = m_settings->GetCornerMode();
 
 switch( m_settings->GetCornerMode() )
 {
 case DIRECTION_45::CORNER_MODE::MITERED_45: mode = DIRECTION_45::CORNER_MODE::ROUNDED_45; break;
 case DIRECTION_45::CORNER_MODE::ROUNDED_45: mode = DIRECTION_45::CORNER_MODE::MITERED_90; break;
 case DIRECTION_45::CORNER_MODE::MITERED_90: mode = DIRECTION_45::CORNER_MODE::ROUNDED_90; break;
 case DIRECTION_45::CORNER_MODE::ROUNDED_90: mode = DIRECTION_45::CORNER_MODE::MITERED_45; break;
 }
 
 m_settings->SetCornerMode( mode );
}
 
 
void ROUTER::SetOrthoMode( bool aEnable )
{
 if( !m_placer )
 return;
 
 m_placer->SetOrthoMode( aEnable );
}
 
 
void ROUTER::SetMode( ROUTER_MODE aMode )
{
 m_mode = aMode;
}
 
 
void ROUTER::SetInterface( ROUTER_IFACE *aIface )
{
 m_iface = aIface;
}
 
 
void ROUTER::BreakSegment( ITEM *aItem, const VECTOR2I& aP )
{
 NODE *node = m_world->Branch();
 
 LINE_PLACER placer( this );
 
 if( placer.SplitAdjacentSegments( node, aItem, aP ) )
 {
 CommitRouting( node );
 }
 else
 {
 delete node;
 }
}
 
}