pns_via.cpp

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/*
 * 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 "pns_via.h"
#include "pns_node.h"
#include "pns_utils.h"
#include "pns_router.h"
#include "pns_debug_decorator.h"
 
#include <geometry/shape_rect.h>
#include <math/box2.h>
 
namespace PNS {
 
bool VIA::PushoutForce( NODE* aNode, const ITEM* aOther, VECTOR2I& aForce )
{
 int clearance = aNode->GetClearance( this, aOther, false );
 VECTOR2I elementForces[4], force;
 size_t nf = 0;
 
 aOther->Shape()->Collide( Shape(), clearance, &elementForces[nf++] );
 
 for( size_t i = 0; i < nf; i++ )
 {
 if( elementForces[i].SquaredEuclideanNorm() > force.SquaredEuclideanNorm() )
 force = elementForces[i];
 }
 
 aForce = force;
 
 return ( force != VECTOR2I( 0, 0 ) );
}
 
bool VIA::PushoutForce( NODE* aNode, const VECTOR2I& aDirection, VECTOR2I& aForce,
 int aCollisionMask, int aMaxIterations )
{
 int iter = 0;
 VIA mv( *this );
 VECTOR2I totalForce;
 
 auto dbg = ROUTER::GetInstance()->GetInterface()->GetDebugDecorator();
 PNS_DBG( dbg, AddPoint, Pos(), YELLOW, 100000, wxString::Format( "via-force-init-pos, iter %d", aMaxIterations ) );
 
 while( iter < aMaxIterations )
 {
 COLLISION_SEARCH_OPTIONS opt;
 opt.m_limitCount = 1;
 opt.m_kindMask = aCollisionMask;
 opt.m_useClearanceEpsilon = false;
 
 NODE::OPT_OBSTACLE obs = aNode->CheckColliding( &mv, opt );
 
 if( !obs )
 break;
 
 VECTOR2I force;
 bool collFound = mv.PushoutForce( aNode, obs->m_item, force );
 
 if( !collFound )
 {
 if( obs )
 {
 // might happen (although rarely) that we see a collision, but the MTV
 // is zero... Assume force propagation has failed in such case.
 return false;
 }
 PNS_DBG( dbg, Message, wxString::Format( "no-coll %d", iter ) );
 break;
 }
 
 const int threshold = Diameter() / 4; // another stupid heuristic.
 const int forceMag = force.EuclideanNorm();
 
 // We've been through a lot of iterations already and our pushout force is still too big?
 // Perhaps the barycentric force goes in the wrong direction, let's try to move along
 // the 'lead' vector instead (usually backwards to the cursor)
 if( iter > aMaxIterations / 2 && forceMag > threshold )
 {
 VECTOR2I l = aDirection.Resize( threshold );
 totalForce += l;
 
 SHAPE_LINE_CHAIN ff;
 ff.Append( mv.Pos() );
 ff.Append( mv.Pos() + l );
 
 mv.SetPos( mv.Pos() + l );
 
 PNS_DBG( dbg, AddShape, &ff, YELLOW, 100000, "via-force-lead" );
 }
 else if( collFound ) // push along the minmum translation vector
 {
 // Limit the force magnitude to, say, 25% of the via diameter
 // This adds a few iterations for large areas (e.g. keepouts)
 // But makes the algorithm more predictable and less 'jumpy'
 if( forceMag > threshold )
 {
 force.Resize( threshold );
 }
 
 totalForce += force;
 
 SHAPE_LINE_CHAIN ff;
 ff.Append( mv.Pos() );
 ff.Append( mv.Pos() + force );
 
 mv.SetPos( mv.Pos() + force );
 
 PNS_DBG( dbg, AddShape, &ff, WHITE, 100000, "via-force-coll" );
 }
 
 iter++;
 }
 
 if( iter == aMaxIterations )
 return false;
 
 PNS_DBG( dbg, AddPoint, ( Pos() + totalForce ), WHITE, 1000000, "via-force-new" );
 
 aForce = totalForce;
 
 return true;
}
 
 
const SHAPE_LINE_CHAIN VIA::Hull( int aClearance, int aWalkaroundThickness, int aLayer ) const
{
 int cl = ( aClearance + aWalkaroundThickness / 2 );
 int width = m_diameter;
 
 if( m_hole && !ROUTER::GetInstance()->GetInterface()->IsFlashedOnLayer( this, aLayer ) )
 width = m_hole->Radius() * 2;
 
 // Chamfer = width * ( 1 - sqrt(2)/2 ) for equilateral octagon
 return OctagonalHull( m_pos - VECTOR2I( width / 2, width / 2 ),
 VECTOR2I( width, width ),
 cl, ( 2 * cl + width ) * ( 1.0 - M_SQRT1_2 ) );
}
 
 
VIA* VIA::Clone() const
{
 VIA* v = new VIA();
 
 v->SetNet( Net() );
 v->SetLayers( Layers() );
 v->m_pos = m_pos;
 v->m_diameter = m_diameter;
 v->m_drill = m_drill;
 v->m_shape = SHAPE_CIRCLE( m_pos, m_diameter / 2 );
 v->SetHole( HOLE::MakeCircularHole( m_pos, m_drill / 2 ) );
 v->m_rank = m_rank;
 v->m_marker = m_marker;
 v->m_viaType = m_viaType;
 v->m_parent = m_parent;
 v->m_isFree = m_isFree;
 v->m_isVirtual = m_isVirtual;
 
 return v;
}
 
 
OPT_BOX2I VIA::ChangedArea( const VIA* aOther ) const
{
 if( aOther->Pos() != Pos() )
 {
 BOX2I tmp = Shape()->BBox();
 tmp.Merge( aOther->Shape()->BBox() );
 return tmp;
 }
 
 return OPT_BOX2I();
}
 
 
const VIA_HANDLE VIA::MakeHandle() const
{
 VIA_HANDLE h;
 h.pos = Pos();
 h.layers = Layers();
 h.net = Net();
 h.valid = true;
 return h;
}
 
 
const std::string VIA::Format( ) const
{
 std::stringstream ss;
 ss << ITEM::Format() << " drill " << m_drill << " ";
 ss << m_shape.Format( false );
 return ss.str();
}
 
}