pns_meander_placer_base.cpp

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/*
 * KiRouter - a push-and-(sometimes-)shove PCB router
 *
 * Copyright (C) 2013-2015 CERN
 * Copyright (C) 2016-2022 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_meander_placer_base.h"
#include "pns_meander.h"
#include "pns_router.h"
#include "pns_solid.h"
#include "pns_arc.h"
 
namespace PNS {
 
const int LENGTH_TARGET_TOLERANCE = 20;
 
MEANDER_PLACER_BASE::MEANDER_PLACER_BASE( ROUTER* aRouter ) :
 PLACEMENT_ALGO( aRouter )
{
 m_world = nullptr;
 m_currentWidth = 0;
 m_startPad_n = nullptr;
 m_startPad_p = nullptr;
 m_endPad_n = nullptr;
 m_endPad_p = nullptr;
}
 
 
MEANDER_PLACER_BASE::~MEANDER_PLACER_BASE()
{
}
 
 
void MEANDER_PLACER_BASE::AmplitudeStep( int aSign )
{
 int a = m_settings.m_maxAmplitude + aSign * m_settings.m_step;
 a = std::max( a, m_settings.m_minAmplitude );
 
 m_settings.m_maxAmplitude = a;
}
 
 
void MEANDER_PLACER_BASE::SpacingStep( int aSign )
{
 int s = m_settings.m_spacing + aSign * m_settings.m_step;
 s = std::max( s, m_currentWidth + Clearance() );
 
 m_settings.m_spacing = s;
}
 
 
int MEANDER_PLACER_BASE::Clearance()
{
 // Assumption: All tracks are part of the same net class.
 // It shouldn't matter which track we pick. They should all have the same clearance if
 // they are part of the same net class. Therefore, pick the first one on the list.
 ITEM* itemToCheck = Traces().CItems().front();
 PNS::CONSTRAINT constraint;
 
 Router()->GetRuleResolver()->QueryConstraint( PNS::CONSTRAINT_TYPE::CT_CLEARANCE, itemToCheck,
 nullptr, CurrentLayer(), &constraint );
 
 wxCHECK_MSG( constraint.m_Value.HasMin(), m_currentWidth, wxT( "No minimum clearance?" ) );
 
 return constraint.m_Value.Min();
}
 
 
void MEANDER_PLACER_BASE::UpdateSettings( const MEANDER_SETTINGS& aSettings )
{
 m_settings = aSettings;
}
 
 
int findAmplitudeBinarySearch( MEANDER_SHAPE& aCopy, int targetLength, int minAmp, int maxAmp )
{
 if( minAmp == maxAmp )
 return maxAmp;
 
 aCopy.Resize( minAmp );
 int minLen = aCopy.CurrentLength();
 
 aCopy.Resize( maxAmp );
 int maxLen = aCopy.CurrentLength();
 
 if( minLen > targetLength )
 return 0;
 
 if( maxLen < targetLength )
 return 0;
 
 int minError = minLen - targetLength;
 int maxError = maxLen - targetLength;
 
 if( std::abs( minError ) < LENGTH_TARGET_TOLERANCE
 || std::abs( maxError ) < LENGTH_TARGET_TOLERANCE )
 {
 return std::abs( minError ) < std::abs( maxError ) ? minAmp : maxAmp;
 }
 else
 {
 int left =
 findAmplitudeBinarySearch( aCopy, targetLength, minAmp, ( minAmp + maxAmp ) / 2 );
 
 if( left )
 return left;
 
 int right =
 findAmplitudeBinarySearch( aCopy, targetLength, ( minAmp + maxAmp ) / 2, maxAmp );
 
 if( right )
 return right;
 }
 
 return 0;
}
 
 
int findAmplitudeForLength( MEANDER_SHAPE* m, int targetLength, int minAmp, int maxAmp )
{
 MEANDER_SHAPE copy = *m;
 
 // Try to keep the same baseline length
 copy.SetTargetBaselineLength( m->BaselineLength() );
 
 long long initialGuess = m->Amplitude() - ( m->CurrentLength() - targetLength ) / 2;
 
 if( initialGuess >= minAmp && initialGuess <= maxAmp )
 {
 copy.Resize( minAmp );
 
 if( std::abs( copy.CurrentLength() - targetLength ) < LENGTH_TARGET_TOLERANCE )
 return initialGuess;
 }
 
 // The length is non-trivial, use binary search
 return findAmplitudeBinarySearch( copy, targetLength, minAmp, maxAmp );
}
 
 
void MEANDER_PLACER_BASE::tuneLineLength( MEANDERED_LINE& aTuned, long long int aElongation )
{
 long long int maxElongation = 0;
 long long int minElongation = 0;
 bool finished = false;
 
 for( MEANDER_SHAPE* m : aTuned.Meanders() )
 {
 if( m->Type() != MT_CORNER && m->Type() != MT_ARC )
 {
 MEANDER_SHAPE end = *m;
 MEANDER_TYPE endType;
 
 if( m->Type() == MT_START || m->Type() == MT_SINGLE )
 endType = MT_SINGLE;
 else
 endType = MT_FINISH;
 
 end.SetType( endType );
 end.Recalculate();
 
 long long int maxEndElongation = end.CurrentLength() - end.BaselineLength();
 
 if( maxElongation + maxEndElongation > aElongation )
 {
 if( !finished )
 {
 m->SetType( endType );
 m->Recalculate();
 
 if( endType == MT_SINGLE )
 {
 // Check if we need to fit this meander
 long long int endMinElongation =
 ( m->MinTunableLength() - m->BaselineLength() );
 
 if( minElongation + endMinElongation >= aElongation )
 m->MakeEmpty();
 }
 
 finished = true;
 }
 else
 {
 m->MakeEmpty();
 }
 }
 
 maxElongation += m->CurrentLength() - m->BaselineLength();
 minElongation += m->MinTunableLength() - m->BaselineLength();
 }
 }
 
 long long int remainingElongation = aElongation;
 int meanderCount = 0;
 
 for( MEANDER_SHAPE* m : aTuned.Meanders() )
 {
 if( m->Type() != MT_CORNER && m->Type() != MT_ARC && m->Type() != MT_EMPTY )
 {
 remainingElongation -= m->CurrentLength() - m->BaselineLength();
 meanderCount++;
 }
 }
 
 long long int lenReductionLeft = -remainingElongation;
 int meandersLeft = meanderCount;
 
 if( lenReductionLeft < 0 || !meandersLeft )
 return;
 
 for( MEANDER_SHAPE* m : aTuned.Meanders() )
 {
 if( m->Type() != MT_CORNER && m->Type() != MT_ARC && m->Type() != MT_EMPTY )
 {
 long long int lenReductionHere = lenReductionLeft / meandersLeft;
 long long int initialLen = m->CurrentLength();
 int minAmpl = m->MinAmplitude();
 
 int amp = findAmplitudeForLength( m, initialLen - lenReductionHere, minAmpl,
 m->Amplitude() );
 
 if( amp < minAmpl )
 amp = minAmpl;
 
 m->SetTargetBaselineLength( m->BaselineLength() );
 m->Resize( amp );
 
 lenReductionLeft -= initialLen - m->CurrentLength();
 meandersLeft--;
 
 if( !meandersLeft )
 break;
 }
 }
}
 
 
int MEANDER_PLACER_BASE::GetTotalPadToDieLength( const LINE& aLine ) const
{
 int length = 0;
 JOINT start;
 JOINT end;
 
 m_world->FindLineEnds( aLine, start, end );
 
 // Extract the length of the pad to die for start and end pads
 for( auto& link : start.LinkList() )
 {
 if( const SOLID* solid = dyn_cast<const SOLID*>( link ) )
 {
 // If there are overlapping pads, choose the first with a non-zero length
 if( solid->GetPadToDie() > 0 )
 {
 length += solid->GetPadToDie();
 break;
 }
 }
 }
 
 for( auto& link : end.LinkList() )
 {
 if( const SOLID* solid = dyn_cast<const SOLID*>( link ) )
 {
 if( solid->GetPadToDie() > 0 )
 {
 length += solid->GetPadToDie();
 break;
 }
 }
 }
 
 return length;
}
 
 
const MEANDER_SETTINGS& MEANDER_PLACER_BASE::MeanderSettings() const
{
 return m_settings;
}
 
 
VECTOR2I MEANDER_PLACER_BASE::getSnappedStartPoint( LINKED_ITEM* aStartItem, VECTOR2I aStartPoint )
{
 if( aStartItem->Kind() == ITEM::SEGMENT_T )
 {
 return static_cast<SEGMENT*>( aStartItem )->Seg().NearestPoint( aStartPoint );
 }
 else
 {
 wxASSERT( aStartItem->Kind() == ITEM::ARC_T );
 ARC* arc = static_cast<ARC*>( aStartItem );
 
 if( ( VECTOR2I( arc->Anchor( 0 ) - aStartPoint ) ).SquaredEuclideanNorm() <=
 ( VECTOR2I( arc->Anchor( 1 ) - aStartPoint ) ).SquaredEuclideanNorm() )
 {
 return arc->Anchor( 0 );
 }
 else
 {
 return arc->Anchor( 1 );
 }
 }
}
 
 
long long int MEANDER_PLACER_BASE::lineLength( const ITEM_SET& aLine, const SOLID* aStartPad, const SOLID* aEndPad ) const
{
 long long int total = 0;
 
 if( aLine.Empty() )
 return 0;
 
 const ITEM* start_item = aLine[0];
 const ITEM* end_item = aLine[aLine.Size() - 1];
 bool start_via = false;
 bool end_via = false;
 
 
 start_via = aStartPad && ( !aStartPad->LayersOverlap( start_item ) );
 end_via = aEndPad && ( !aEndPad->LayersOverlap( end_item ) );
 
 for( int idx = 0; idx < aLine.Size(); idx++ )
 {
 const ITEM* item = aLine[idx];
 
 if( const LINE* l = dyn_cast<const LINE*>( item ) )
 {
 total += l->CLine().Length();
 }
 else if( item->OfKind( ITEM::VIA_T ) && idx > 0 && idx < aLine.Size() - 1 )
 {
 int layerPrev = aLine[idx - 1]->Layer();
 int layerNext = aLine[idx + 1]->Layer();
 
 if( layerPrev != layerNext )
 total += m_router->GetInterface()->StackupHeight( layerPrev, layerNext );
 }
 }
 
 if( start_via )
 {
 int layerPrev = aStartPad->Layer();
 int layerNext = start_item->Layer();
 
 total += m_router->GetInterface()->StackupHeight( layerPrev, layerNext );
 }
 
 if( end_via )
 {
 int layerPrev = end_item->Layer();
 int layerNext = aEndPad->Layer();
 
 total += m_router->GetInterface()->StackupHeight( layerPrev, layerNext );
 }
 
 return total;
}
 
}