bool PNS_DIFF_PAIR_PLACER::propagateDpHeadForces ( const VECTOR2I& aP, VECTOR2I& aNewP )
{
    PNS_VIA virtHead = makeVia( aP, -1 );

    if( m_placingVia )
        virtHead.SetDiameter( viaGap() + 2 * virtHead.Diameter() );
    else
    {
        virtHead.SetLayer( m_currentLayer );
        virtHead.SetDiameter( m_sizes.DiffPairGap() + 2 * m_sizes.TrackWidth() );
    }

    VECTOR2I lead( 0, 0 );// = aP - m_currentStart ;
    VECTOR2I force;
    bool solidsOnly = true;

    if( m_currentMode == RM_MarkObstacles )
    {
        aNewP = aP;
        return true;
    }
    else if( m_currentMode == RM_Walkaround )
    {
        solidsOnly = false;
    }

    // fixme: I'm too lazy to do it well. Circular approximaton will do for the moment.
    if( virtHead.PushoutForce( m_currentNode, lead, force, solidsOnly, 40 ) )
    {
        aNewP = aP + force;
        return true;
    }

    return false;
}
void PNS_ROUTER::CommitRouting( PNS_NODE* aNode )
{
    PNS_NODE::ITEM_VECTOR removed, added;

    aNode->GetUpdatedItems( removed, added );

    for( unsigned int i = 0; i < removed.size(); i++ )
    {
        BOARD_CONNECTED_ITEM* parent = removed[i]->Parent();

        if( parent )
        {
            m_view->Remove( parent );
            m_board->Remove( parent );
            m_undoBuffer.PushItem( ITEM_PICKER( parent, UR_DELETED ) );
        }
    }

    for( PNS_ITEM* item : added )
    {
        BOARD_CONNECTED_ITEM* newBI = NULL;

        switch( item->Kind() )
        {
        case PNS_ITEM::SEGMENT:
        {
            PNS_SEGMENT* seg = static_cast<PNS_SEGMENT*>( item );
            TRACK* track = new TRACK( m_board );
            const SEG& s = seg->Seg();

            track->SetStart( wxPoint( s.A.x, s.A.y ) );
            track->SetEnd( wxPoint( s.B.x, s.B.y ) );
            track->SetWidth( seg->Width() );
            track->SetLayer( ToLAYER_ID( seg->Layers().Start() ) );
            track->SetNetCode( seg->Net() > 0 ? seg->Net() : 0 );
            newBI = track;
            break;
        }

        case PNS_ITEM::VIA:
        {
            VIA* via_board = new VIA( m_board );
            PNS_VIA* via = static_cast<PNS_VIA*>( item );
            via_board->SetPosition( wxPoint( via->Pos().x, via->Pos().y ) );
            via_board->SetWidth( via->Diameter() );
            via_board->SetDrill( via->Drill() );
            via_board->SetNetCode( via->Net() > 0 ? via->Net() : 0 );
            via_board->SetViaType( via->ViaType() ); // MUST be before SetLayerPair()
            via_board->SetLayerPair( ToLAYER_ID( via->Layers().Start() ),
                                     ToLAYER_ID( via->Layers().End() ) );
            newBI = via_board;
            break;
        }

        default:
            break;
        }

        if( newBI )
        {
            item->SetParent( newBI );
            newBI->ClearFlags();
            m_view->Add( newBI );
            m_board->Add( newBI );
            m_undoBuffer.PushItem( ITEM_PICKER( newBI, UR_NEW ) );
            newBI->ViewUpdate( KIGFX::VIEW_ITEM::GEOMETRY );
        }
    }

    m_board->GetRatsnest()->Recalculate();
    m_world->Commit( aNode );
}