pns_meander_skew_placer.cpp

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/*
 * KiRouter - a push-and-(sometimes-)shove PCB router
 *
 * Copyright (C) 2013-2015 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 "pns_node.h"
#include "pns_itemset.h"
#include "pns_topology.h"
#include "pns_meander_skew_placer.h"
#include "pns_solid.h"
 
#include "pns_router.h"
#include "pns_debug_decorator.h"
 
namespace PNS {
 
MEANDER_SKEW_PLACER::MEANDER_SKEW_PLACER ( ROUTER* aRouter ) :
 MEANDER_PLACER ( aRouter )
{
 // Init temporary variables (do not leave uninitialized members)
 m_coupledLength = 0;
 m_padToDieN = 0;
 m_padToDieP = 0;
}
 
 
MEANDER_SKEW_PLACER::~MEANDER_SKEW_PLACER( )
{
}
 
 
bool MEANDER_SKEW_PLACER::Start( const VECTOR2I& aP, ITEM* aStartItem )
{
 if( !aStartItem || !aStartItem->OfKind( ITEM::SEGMENT_T | ITEM::ARC_T) )
 {
 Router()->SetFailureReason( _( "Please select a differential pair trace you want to tune." ) );
 return false;
 }
 
 m_initialSegment = static_cast<LINKED_ITEM*>( aStartItem );
 m_currentNode = nullptr;
 m_currentStart = getSnappedStartPoint( m_initialSegment, aP );
 
 m_world = Router()->GetWorld( )->Branch();
 m_originLine = m_world->AssembleLine( m_initialSegment );
 
 TOPOLOGY topo( m_world );
 m_tunedPath = topo.AssembleTrivialPath( m_initialSegment, nullptr, true );
 
 if( !topo.AssembleDiffPair ( m_initialSegment, m_originPair ) )
 {
 Router()->SetFailureReason( _( "Unable to find complementary differential pair "
 "net for skew tuning. Make sure the names of the nets belonging "
 "to a differential pair end with either _N/_P or +/-." ) );
 return false;
 }
 
 if( m_originPair.Gap() < 0 )
 m_originPair.SetGap( Router()->Sizes().DiffPairGap() );
 
 if( !m_originPair.PLine().SegmentCount() ||
 !m_originPair.NLine().SegmentCount() )
 return false;
 
 m_tunedPathP = topo.AssembleTuningPath( m_originPair.PLine().GetLink( 0 ), &m_startPad_p, &m_endPad_p );
 
 m_padToDieP = 0;
 
 if( m_startPad_p )
 m_padToDieP += m_startPad_p->GetPadToDie();
 
 if( m_endPad_p )
 m_padToDieP += m_endPad_p->GetPadToDie();
 
 m_tunedPathN = topo.AssembleTuningPath( m_originPair.NLine().GetLink( 0 ), &m_startPad_n, &m_endPad_n );
 
 m_padToDieN = 0;
 
 if( m_startPad_n )
 m_padToDieN += m_startPad_n->GetPadToDie();
 
 if( m_endPad_n )
 m_padToDieN += m_endPad_n->GetPadToDie();
 
 m_world->Remove( m_originLine );
 
 m_currentWidth = m_originLine.Width();
 m_currentEnd = VECTOR2I( 0, 0 );
 
 if ( m_originPair.NetP() == m_originLine.Net() )
 {
 m_coupledLength = m_padToDieN + lineLength( m_tunedPathN, m_startPad_n, m_endPad_n );
 m_lastLength = m_padToDieP + lineLength( m_tunedPathP, m_startPad_p, m_endPad_p );
 m_tunedPath = m_tunedPathP;
 }
 else
 {
 m_coupledLength = m_padToDieP + lineLength( m_tunedPathP, m_startPad_p, m_endPad_p );
 m_lastLength = m_padToDieN + lineLength( m_tunedPathN, m_startPad_n, m_endPad_n );
 m_tunedPath = m_tunedPathN;
 }
 
 return true;
}
 
 
long long int MEANDER_SKEW_PLACER::origPathLength() const
{
 if ( m_originPair.NetP() == m_originLine.Net() )
 return m_padToDieP + lineLength( m_tunedPath, m_startPad_p, m_endPad_p );
 
 return m_padToDieN + lineLength( m_tunedPath, m_startPad_n, m_endPad_n );
 
}
 
 
long long int MEANDER_SKEW_PLACER::CurrentSkew() const
{
 return m_lastLength - m_coupledLength;
}
 
 
bool MEANDER_SKEW_PLACER::Move( const VECTOR2I& aP, ITEM* aEndItem )
{
 bool isPositive = m_originPair.NetP() == m_originLine.Net();
 
 for( const ITEM* item : m_tunedPathP.CItems() )
 {
 if( const LINE* l = dyn_cast<const LINE*>( item ) )
 {
 PNS_DBG( Dbg(), AddItem, l, BLUE, 10000, wxT( "tuned-path-skew-p" ) );
 
 m_router->GetInterface()->DisplayPathLine( l->CLine(), isPositive ? 1 : 0 );
 }
 }
 
 for( const ITEM* item : m_tunedPathN.CItems() )
 {
 if( const LINE* l = dyn_cast<const LINE*>( item ) )
 {
 PNS_DBG( Dbg(), AddItem, l, YELLOW, 10000, wxT( "tuned-path-skew-n" ) );
 
 m_router->GetInterface()->DisplayPathLine( l->CLine(), isPositive ? 0 : 1 );
 }
 }
 
 return doMove( aP, aEndItem, m_coupledLength + m_settings.m_targetSkew.Opt(),
 m_coupledLength + m_settings.m_targetSkew.Min(),
 m_coupledLength + m_settings.m_targetSkew.Max() );
}
 
 
long long int MEANDER_SKEW_PLACER::TuningResult() const
{
 return m_lastLength - m_coupledLength;
}
 
}