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 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 <base_units.h> // God forgive me doing this...

#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 );

 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;

 SOLID* padA = nullptr;
 SOLID* padB = nullptr;

 m_tunedPathP = topo.AssembleTuningPath( m_originPair.PLine().GetLink( 0 ), &padA, &padB );

 m_padToDieP = 0;

 if( padA )
 m_padToDieP += padA->GetPadToDie();

 if( padB )
 m_padToDieP += padB->GetPadToDie();

 m_tunedPathN = topo.AssembleTuningPath( m_originPair.NLine().GetLink( 0 ), &padA, &padB );

 m_padToDieN = 0;

 if( padA )
 m_padToDieN += padA->GetPadToDie();

 if( padB )
 m_padToDieN += padB->GetPadToDie();

 m_world->Remove( m_originLine );

 m_currentWidth = m_originLine.Width();
 m_currentEnd = VECTOR2I( 0, 0 );

 if ( m_originPair.PLine().Net() == m_originLine.Net() )
 {
 m_padToDieLength = m_padToDieN;
 m_coupledLength = lineLength( m_tunedPathN );
 m_tunedPath = m_tunedPathP;
 }
 else
 {
 m_padToDieLength = m_padToDieP;
 m_coupledLength = lineLength( m_tunedPathP );
 m_tunedPath = m_tunedPathN;
 }

 return true;
}


long long int MEANDER_SKEW_PLACER::origPathLength() const
{
 return m_padToDieLength + lineLength( m_tunedPath );
}


long long int MEANDER_SKEW_PLACER::currentSkew() const
{
 return m_lastLength - m_coupledLength;
}


bool MEANDER_SKEW_PLACER::Move( const VECTOR2I& aP, ITEM* aEndItem )
{
 for( const ITEM* item : m_tunedPathP.CItems() )
 {
 if( const LINE* l = dyn_cast<const LINE*>( item ) )
 PNS_DBG( Dbg(), AddLine, l->CLine(), BLUE, 10000, "tuned-path-skew-p" );
 }

 for( const ITEM* item : m_tunedPathN.CItems() )
 {
 if( const LINE* l = dyn_cast<const LINE*>( item ) )
 PNS_DBG( Dbg(), AddLine, l->CLine(), YELLOW, 10000, "tuned-path-skew-n" );
 }

 return doMove( aP, aEndItem, m_coupledLength + m_settings.m_targetSkew );
}


const wxString MEANDER_SKEW_PLACER::TuningInfo( EDA_UNITS aUnits ) const
{
 wxString status;

 switch( m_lastStatus )
 {
 case TOO_LONG:
 status = _( "Too long: skew " );
 break;
 case TOO_SHORT:
 status = _( "Too short: skew " );
 break;
 case TUNED:
 status = _( "Tuned: skew " );
 break;
 default:
 return _( "?" );
 }

 status += ::MessageTextFromValue( aUnits, m_lastLength - m_coupledLength );
 status += wxT( "/" );
 status += ::MessageTextFromValue( aUnits, m_settings.m_targetSkew );

 return status;
}

}