ratsnest_data.cpp

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/*
 * This program source code file is part of KICAD, a free EDA CAD application.
 *
 * Copyright (C) 2013-2017 CERN
 * Copyright (C) 2019-2021 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * @author Maciej Suminski <[email protected]>
 * @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 2
 * 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, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */

#ifdef PROFILE
#include <profile.h>
#endif

#include <ratsnest/ratsnest_data.h>
#include <functional>
using namespace std::placeholders;

#include <algorithm>
#include <cassert>
#include <limits>

#include <delaunator.hpp>

class disjoint_set
{

public:
 disjoint_set( size_t size )
 {
 m_data.resize( size );
 m_depth.resize( size, 0 );

 for( size_t i = 0; i < size; i++ )
 m_data[i] = i;
 }

 int find( int aVal )
 {
 int root = aVal;

 while( m_data[root] != root )
 root = m_data[root];

 // Compress the path
 while( m_data[aVal] != aVal )
 {
 auto& tmp = m_data[aVal];
 aVal = tmp;
 tmp = root;
 }

 return root;
 }


 bool unite( int aVal1, int aVal2 )
 {
 aVal1 = find( aVal1 );
 aVal2 = find( aVal2 );

 if( aVal1 != aVal2 )
 {
 if( m_depth[aVal1] < m_depth[aVal2] )
 {
 m_data[aVal1] = aVal2;
 }
 else
 {
 m_data[aVal2] = aVal1;

 if( m_depth[aVal1] == m_depth[aVal2] )
 m_depth[aVal1]++;
 }

 return true;
 }

 return false;
 }

private:
 std::vector<int> m_data;
 std::vector<int> m_depth;
};


void RN_NET::kruskalMST( const std::vector<CN_EDGE> &aEdges )
{
 disjoint_set dset( m_nodes.size() );

 m_rnEdges.clear();

 int i = 0;

 for( const CN_ANCHOR_PTR& node : m_nodes )
 node->SetTag( i++ );

 for( const CN_EDGE& tmp : aEdges )
 {
 int u = tmp.GetSourceNode()->GetTag();
 int v = tmp.GetTargetNode()->GetTag();

 if( dset.unite( u, v ) )
 {
 if( tmp.GetWeight() > 0 )
 m_rnEdges.push_back( tmp );
 }
 }
}


class RN_NET::TRIANGULATOR_STATE
{
private:
 std::multiset<CN_ANCHOR_PTR, CN_PTR_CMP> m_allNodes;


 // Checks if all nodes in aNodes lie on a single line. Requires the nodes to
 // have unique coordinates!
 bool areNodesColinear( const std::vector<CN_ANCHOR_PTR>& aNodes ) const
 {
 if ( aNodes.size() <= 2 )
 return true;

 const VECTOR2I p0( aNodes[0]->Pos() );
 const VECTOR2I v0( aNodes[1]->Pos() - p0 );

 for( unsigned i = 2; i < aNodes.size(); i++ )
 {
 const VECTOR2I v1 = aNodes[i]->Pos() - p0;

 if( v0.Cross( v1 ) != 0 )
 return false;
 }

 return true;
 }

public:

 void Clear()
 {
 m_allNodes.clear();
 }

 void AddNode( CN_ANCHOR_PTR aNode )
 {
 m_allNodes.insert( aNode );
 }

 void Triangulate( std::vector<CN_EDGE>& mstEdges)
 {
 std::vector<double> node_pts;
 std::vector<CN_ANCHOR_PTR> anchors;
 std::vector< std::vector<CN_ANCHOR_PTR> > anchorChains( m_allNodes.size() );

 node_pts.reserve( 2 * m_allNodes.size() );
 anchors.reserve( m_allNodes.size() );

 CN_ANCHOR_PTR prev = nullptr;

 for( const CN_ANCHOR_PTR& n : m_allNodes )
 {
 if( !prev || prev->Pos() != n->Pos() )
 {
 node_pts.push_back( n->Pos().x );
 node_pts.push_back( n->Pos().y );
 anchors.push_back( n );
 prev = n;
 }

 anchorChains[anchors.size() - 1].push_back( n );
 }

 if( anchors.size() < 2 )
 {
 return;
 }
 else if( areNodesColinear( anchors ) )
 {
 // special case: all nodes are on the same line - there's no
 // triangulation for such set. In this case, we sort along any coordinate
 // and chain the nodes together.
 for( size_t i = 0; i < anchors.size() - 1; i++ )
 {
 const CN_ANCHOR_PTR& src = anchors[i];
 const CN_ANCHOR_PTR& dst = anchors[i + 1];
 mstEdges.emplace_back( src, dst, src->Dist( *dst ) );
 }
 }
 else
 {
 delaunator::Delaunator delaunator( node_pts );
 auto& triangles = delaunator.triangles;

 for( size_t i = 0; i < triangles.size(); i += 3 )
 {
 CN_ANCHOR_PTR& src = anchors[triangles[i]];
 CN_ANCHOR_PTR& dst = anchors[triangles[i + 1]];
 mstEdges.emplace_back( src, dst, src->Dist( *dst ) );

 src = anchors[triangles[i + 1]];
 dst = anchors[triangles[i + 2]];
 mstEdges.emplace_back( src, dst, src->Dist( *dst ) );

 src = anchors[triangles[i + 2]];
 dst = anchors[triangles[i]];
 mstEdges.emplace_back( src, dst, src->Dist( *dst ) );
 }

 for( size_t i = 0; i < delaunator.halfedges.size(); i++ )
 {
 if( delaunator.halfedges[i] == delaunator::INVALID_INDEX )
 continue;

 const CN_ANCHOR_PTR& src = anchors[triangles[i]];
 const CN_ANCHOR_PTR& dst = anchors[triangles[delaunator.halfedges[i]]];
 mstEdges.emplace_back( src, dst, src->Dist( *dst ) );
 }
 }

 for( size_t i = 0; i < anchorChains.size(); i++ )
 {
 std::vector<CN_ANCHOR_PTR>& chain = anchorChains[i];

 if( chain.size() < 2 )
 continue;

 std::sort( chain.begin(), chain.end(),
 [] ( const CN_ANCHOR_PTR& a, const CN_ANCHOR_PTR& b )
 {
 return a->GetCluster().get() < b->GetCluster().get();
 } );

 for( unsigned int j = 1; j < chain.size(); j++ )
 {
 const CN_ANCHOR_PTR& prevNode = chain[j - 1];
 const CN_ANCHOR_PTR& curNode = chain[j];
 int weight = prevNode->GetCluster() != curNode->GetCluster() ? 1 : 0;
 mstEdges.emplace_back( prevNode, curNode, weight );
 }
 }
 }
};


RN_NET::RN_NET() : m_dirty( true )
{
 m_triangulator.reset( new TRIANGULATOR_STATE );
}


void RN_NET::compute()
{
 // Special cases do not need complicated algorithms (actually, it does not work well with
 // the Delaunay triangulator)
 if( m_nodes.size() <= 2 )
 {
 m_rnEdges.clear();

 // Check if the only possible connection exists
 if( m_boardEdges.size() == 0 && m_nodes.size() == 2 )
 {
 auto last = ++m_nodes.begin();

 // There can be only one possible connection, but it is missing
 CN_EDGE edge ( *m_nodes.begin(), *last );
 edge.GetSourceNode()->SetTag( 0 );
 edge.GetTargetNode()->SetTag( 1 );

 m_rnEdges.push_back( edge );
 }
 else
 {
 // Set tags to m_nodes as connected
 for( const CN_ANCHOR_PTR& node : m_nodes )
 node->SetTag( 0 );
 }

 return;
 }


 m_triangulator->Clear();

 for( const CN_ANCHOR_PTR& n : m_nodes )
 m_triangulator->AddNode( n );

 std::vector<CN_EDGE> triangEdges;
 triangEdges.reserve( m_nodes.size() + m_boardEdges.size() );

#ifdef PROFILE
 PROF_COUNTER cnt("triangulate");
#endif
 m_triangulator->Triangulate( triangEdges );
#ifdef PROFILE
 cnt.Show();
#endif

 for( const CN_EDGE& e : m_boardEdges )
 triangEdges.emplace_back( e );

 std::sort( triangEdges.begin(), triangEdges.end() );

// Get the minimal spanning tree
#ifdef PROFILE
 PROF_COUNTER cnt2("mst");
#endif
 kruskalMST( triangEdges );
#ifdef PROFILE
 cnt2.Show();
#endif
}



void RN_NET::Update()
{
 compute();

 m_dirty = false;
}


void RN_NET::Clear()
{
 m_rnEdges.clear();
 m_boardEdges.clear();
 m_nodes.clear();

 m_dirty = true;
}


void RN_NET::AddCluster( CN_CLUSTER_PTR aCluster )
{
 CN_ANCHOR_PTR firstAnchor;

 for( CN_ITEM* item : *aCluster )
 {
 bool isZone = dynamic_cast<CN_ZONE_LAYER*>( item );
 std::vector<CN_ANCHOR_PTR>& anchors = item->Anchors();
 unsigned int nAnchors = isZone ? 1 : anchors.size();

 if( nAnchors > anchors.size() )
 nAnchors = anchors.size();

 for( unsigned int i = 0; i < nAnchors; i++ )
 {
 anchors[i]->SetCluster( aCluster );
 m_nodes.insert( anchors[i] );

 if( firstAnchor )
 {
 if( firstAnchor != anchors[i] )
 m_boardEdges.emplace_back( firstAnchor, anchors[i], 0 );
 }
 else
 {
 firstAnchor = anchors[i];
 }
 }
 }
}


bool RN_NET::NearestBicoloredPair( const RN_NET& aOtherNet, CN_ANCHOR_PTR& aNode1,
 CN_ANCHOR_PTR& aNode2 ) const
{
 bool rv = false;

 SEG::ecoord distMax_sq = VECTOR2I::ECOORD_MAX;

 auto verify =
 [&]( const std::shared_ptr<CN_ANCHOR>& aTestNode1,
 const std::shared_ptr<CN_ANCHOR>& aTestNode2 )
 {
 VECTOR2I diff = aTestNode1->Pos() - aTestNode2->Pos();
 SEG::ecoord dist_sq = diff.SquaredEuclideanNorm();

 if( dist_sq < distMax_sq )
 {
 rv = true;
 distMax_sq = dist_sq;
 aNode1 = aTestNode1;
 aNode2 = aTestNode2;
 }
 };

 for( const std::shared_ptr<CN_ANCHOR>& nodeA : aOtherNet.m_nodes )
 {
 if( nodeA->GetNoLine() )
 continue;

 auto fwd_it = m_nodes.lower_bound( nodeA );
 auto rev_it = std::make_reverse_iterator( fwd_it );

 for( ; fwd_it != m_nodes.end(); ++fwd_it )
 {
 const std::shared_ptr<CN_ANCHOR>& nodeB = *fwd_it;

 if( nodeB->GetNoLine() )
 continue;

 SEG::ecoord distX_sq = SEG::Square( nodeA->Pos().x - nodeB->Pos().x );

 if( distX_sq > distMax_sq )
 break;

 verify( nodeA, nodeB );
 }

 for( ; rev_it != m_nodes.rend(); ++rev_it )
 {
 const std::shared_ptr<CN_ANCHOR>& nodeB = *rev_it;

 if( nodeB->GetNoLine() )
 continue;

 SEG::ecoord distX_sq = SEG::Square( nodeA->Pos().x - nodeB->Pos().x );

 if( distX_sq > distMax_sq )
 break;

 verify( nodeA, nodeB );
 }
 }

 return rv;
}


void RN_NET::SetVisible( bool aEnabled )
{
 for( CN_EDGE& edge : m_rnEdges )
 edge.SetVisible( aEnabled );
}