convert_shape_list_to_polygon.cpp

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2017 Jean-Pierre Charras, jp.charras at wanadoo.fr
 * Copyright (C) 2015 SoftPLC Corporation, Dick Hollenbeck <[email protected]>
 * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * 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
 */
 
#include <trigo.h>
#include <macros.h>
 
#include <math/vector2d.h>
#include <pcb_shape.h>
#include <footprint.h>
#include <pad.h>
#include <base_units.h>
#include <convert_basic_shapes_to_polygon.h>
#include <geometry/shape_poly_set.h>
#include <geometry/geometry_utils.h>
#include <convert_shape_list_to_polygon.h>
 
#include <wx/log.h>
 
 
const wxChar* traceBoardOutline = wxT( "KICAD_BOARD_OUTLINE" );
 
static bool close_enough( VECTOR2I aLeft, VECTOR2I aRight, unsigned aLimit )
{
 return ( aLeft - aRight ).SquaredEuclideanNorm() <= SEG::Square( aLimit );
}
 
static bool closer_to_first( VECTOR2I aRef, VECTOR2I aFirst, VECTOR2I aSecond )
{
 return ( aRef - aFirst ).SquaredEuclideanNorm() < ( aRef - aSecond ).SquaredEuclideanNorm();
}
 
 
static PCB_SHAPE* findNext( PCB_SHAPE* aShape, const VECTOR2I& aPoint,
 const std::vector<PCB_SHAPE*>& aList, unsigned aLimit )
{
 // Look for an unused, exact hit
 for( PCB_SHAPE* graphic : aList )
 {
 if( graphic == aShape || ( graphic->GetFlags() & SKIP_STRUCT ) != 0 )
 continue;
 
 if( aPoint == graphic->GetStart() || aPoint == graphic->GetEnd() )
 return graphic;
 }
 
 // Search again for anything that's close, even something already used. (The latter is
 // important for error reporting.)
 VECTOR2I pt( aPoint );
 SEG::ecoord closest_dist_sq = SEG::Square( aLimit );
 PCB_SHAPE* closest_graphic = nullptr;
 SEG::ecoord d_sq;
 
 for( PCB_SHAPE* graphic : aList )
 {
 if( graphic == aShape )
 continue;
 
 d_sq = ( pt - graphic->GetStart() ).SquaredEuclideanNorm();
 
 if( d_sq < closest_dist_sq )
 {
 closest_dist_sq = d_sq;
 closest_graphic = graphic;
 }
 
 d_sq = ( pt - graphic->GetEnd() ).SquaredEuclideanNorm();
 
 if( d_sq < closest_dist_sq )
 {
 closest_dist_sq = d_sq;
 closest_graphic = graphic;
 }
 }
 
 return closest_graphic; // Note: will be nullptr if nothing within aLimit
}
 
 
static bool isCopperOutside( const FOOTPRINT* aFootprint, SHAPE_POLY_SET& aShape )
{
 bool padOutside = false;
 
 for( PAD* pad : aFootprint->Pads() )
 {
 SHAPE_POLY_SET poly = aShape.CloneDropTriangulation();
 
 poly.BooleanIntersection( *pad->GetEffectivePolygon(), SHAPE_POLY_SET::PM_FAST );
 
 if( poly.OutlineCount() == 0 )
 {
 VECTOR2I padPos = pad->GetPosition();
 wxLogTrace( traceBoardOutline, wxT( "Tested pad (%d, %d): outside" ),
 padPos.x, padPos.y );
 padOutside = true;
 break;
 }
 
 VECTOR2I padPos = pad->GetPosition();
 wxLogTrace( traceBoardOutline, wxT( "Tested pad (%d, %d): not outside" ),
 padPos.x, padPos.y );
 }
 
 return padOutside;
}
 
 
/* Build a polygon (with holes) from a PCB_SHAPE list, which is expected to be a closed main
 * outline with perhaps closed inner outlines. These closed inner outlines are considered as
 * holes in the main outline.
 * @param aShapeList the initial list of SHAPEs (only lines, circles and arcs).
 * @param aPolygons will contain the complex polygon.
 * @param aErrorMax is the max error distance when polygonizing a curve (internal units)
 * @param aChainingEpsilon is the max error distance when polygonizing a curve (internal units)
 * @param aAllowDisjoint indicates multiple top-level outlines are allowed
 * @param aErrorHandler = an optional error handler
 * @param aAllowUseArcsInPolygons = an optional option to allow adding arcs in
 * SHAPE_LINE_CHAIN polylines/polygons when building outlines from aShapeList
 */
bool ConvertOutlineToPolygon( std::vector<PCB_SHAPE*>& aShapeList, SHAPE_POLY_SET& aPolygons,
 int aErrorMax, int aChainingEpsilon, bool aAllowDisjoint,
 OUTLINE_ERROR_HANDLER* aErrorHandler, bool aAllowUseArcsInPolygons )
{
 if( aShapeList.size() == 0 )
 return true;
 
 bool selfIntersecting = false;
 
 wxString msg;
 PCB_SHAPE* graphic = nullptr;
 
 std::set<PCB_SHAPE*> startCandidates( aShapeList.begin(), aShapeList.end() );
 
 // Keep a list of where the various shapes came from so after doing our combined-polygon
 // tests we can still report errors against the individual graphic items.
 std::map<std::pair<VECTOR2I, VECTOR2I>, PCB_SHAPE*> shapeOwners;
 
 auto fetchOwner =
 [&]( const SEG& seg ) -> PCB_SHAPE*
 {
 auto it = shapeOwners.find( std::make_pair( seg.A, seg.B ) );
 return it == shapeOwners.end() ? nullptr : it->second;
 };
 
 PCB_SHAPE* prevGraphic = nullptr;
 VECTOR2I prevPt;
 
 std::vector<SHAPE_LINE_CHAIN> contours;
 
 for( PCB_SHAPE* shape : startCandidates )
 shape->ClearFlags( SKIP_STRUCT );
 
 while( startCandidates.size() )
 {
 graphic = (PCB_SHAPE*) *startCandidates.begin();
 graphic->SetFlags( SKIP_STRUCT );
 startCandidates.erase( startCandidates.begin() );
 
 contours.emplace_back();
 
 SHAPE_LINE_CHAIN& currContour = contours.back();
 bool firstPt = true;
 
 // Circles, rects and polygons are closed shapes unto themselves (and do not combine
 // with other shapes), so process them separately.
 if( graphic->GetShape() == SHAPE_T::POLY )
 {
 for( auto it = graphic->GetPolyShape().CIterate(); it; it++ )
 {
 VECTOR2I pt = *it;
 
 currContour.Append( pt );
 
 if( firstPt )
 firstPt = false;
 else
 shapeOwners[ std::make_pair( prevPt, pt ) ] = graphic;
 
 prevPt = pt;
 }
 
 currContour.SetClosed( true );
 }
 else if( graphic->GetShape() == SHAPE_T::CIRCLE )
 {
 VECTOR2I center = graphic->GetCenter();
 int radius = graphic->GetRadius();
 VECTOR2I start = center;
 start.x += radius;
 
 // Add 360 deg Arc in currContour
 SHAPE_ARC arc360( center, start, ANGLE_360, 0 );
 currContour.Append( arc360, aErrorMax );
 currContour.SetClosed( true );
 
 // set shapeOwners for currContour points created by appending the arc360:
 for( int ii = 1; ii < currContour.PointCount(); ++ii )
 {
 shapeOwners[ std::make_pair( currContour.CPoint( ii-1 ),
 currContour.CPoint( ii ) ) ] = graphic;
 }
 
 if( !aAllowUseArcsInPolygons )
 currContour.ClearArcs();
 }
 else if( graphic->GetShape() == SHAPE_T::RECTANGLE )
 {
 std::vector<VECTOR2I> pts = graphic->GetRectCorners();
 
 for( const VECTOR2I& pt : pts )
 {
 currContour.Append( pt );
 
 if( firstPt )
 firstPt = false;
 else
 shapeOwners[ std::make_pair( prevPt, pt ) ] = graphic;
 
 prevPt = pt;
 }
 
 currContour.SetClosed( true );
 }
 else
 {
 // Polygon start point. Arbitrarily chosen end of the segment and build the poly
 // from here.
 
 VECTOR2I startPt = graphic->GetEnd();
 prevPt = startPt;
 currContour.Append( prevPt );
 
 // do not append the other end point yet, this first 'graphic' might be an arc
 for(;;)
 {
 switch( graphic->GetShape() )
 {
 case SHAPE_T::RECTANGLE:
 case SHAPE_T::CIRCLE:
 {
 // As a non-first item, closed shapes can't be anything but self-intersecting
 
 if( aErrorHandler )
 {
 wxASSERT( prevGraphic );
 (*aErrorHandler)( _( "(self-intersecting)" ), prevGraphic, graphic, prevPt );
 }
 
 selfIntersecting = true;
 
 // A closed shape will finish where it started, so no point in updating prevPt
 break;
 }
 
 case SHAPE_T::SEGMENT:
 {
 VECTOR2I nextPt;
 
 // Use the line segment end point furthest away from prevPt as we assume
 // the other end to be ON prevPt or very close to it.
 
 if( closer_to_first( prevPt, graphic->GetStart(), graphic->GetEnd()) )
 nextPt = graphic->GetEnd();
 else
 nextPt = graphic->GetStart();
 
 currContour.Append( nextPt );
 shapeOwners[ std::make_pair( prevPt, nextPt ) ] = graphic;
 prevPt = nextPt;
 }
 break;
 
 case SHAPE_T::ARC:
 {
 VECTOR2I pstart = graphic->GetStart();
 VECTOR2I pmid = graphic->GetArcMid();
 VECTOR2I pend = graphic->GetEnd();
 
 if( !close_enough( prevPt, pstart, aChainingEpsilon ) )
 {
 wxASSERT( close_enough( prevPt, graphic->GetEnd(), aChainingEpsilon ) );
 
 std::swap( pstart, pend );
 }
 
 SHAPE_ARC sarc( pstart, pmid, pend, 0 );
 
 SHAPE_LINE_CHAIN arcChain;
 arcChain.Append( sarc, aErrorMax );
 
 if( !aAllowUseArcsInPolygons )
 arcChain.ClearArcs();
 
 // set shapeOwners for arcChain points created by appending the sarc:
 for( int ii = 1; ii < arcChain.PointCount(); ++ii )
 {
 shapeOwners[std::make_pair( arcChain.CPoint( ii - 1 ),
 arcChain.CPoint( ii ) )] = graphic;
 }
 
 currContour.Append( arcChain );
 
 prevPt = pend;
 }
 break;
 
 case SHAPE_T::BEZIER:
 // We do not support Bezier curves in polygons, so approximate with a series
 // of short lines and put those line segments into the !same! PATH.
 {
 VECTOR2I nextPt;
 bool reverse = false;
 
 // Use the end point furthest away from prevPt as we assume the other
 // end to be ON prevPt or very close to it.
 
 if( closer_to_first( prevPt, graphic->GetStart(), graphic->GetEnd()) )
 {
 nextPt = graphic->GetEnd();
 }
 else
 {
 nextPt = graphic->GetStart();
 reverse = true;
 }
 
 // Ensure the approximated Bezier shape is built
 // a good value is between (Bezier curve width / 2) and (Bezier curve width)
 // ( and at least 0.05 mm to avoid very small segments)
 int min_segm_length = std::max( pcbIUScale.mmToIU( 0.05 ), graphic->GetWidth() );
 graphic->RebuildBezierToSegmentsPointsList( min_segm_length );
 
 if( reverse )
 {
 for( int jj = graphic->GetBezierPoints().size()-1; jj >= 0; jj-- )
 {
 const VECTOR2I& pt = graphic->GetBezierPoints()[jj];
 
 if( prevPt == pt )
 continue;
 
 currContour.Append( pt );
 shapeOwners[ std::make_pair( prevPt, pt ) ] = graphic;
 prevPt = pt;
 }
 }
 else
 {
 for( const VECTOR2I& pt : graphic->GetBezierPoints() )
 {
 if( prevPt == pt )
 continue;
 
 currContour.Append( pt );
 shapeOwners[ std::make_pair( prevPt, pt ) ] = graphic;
 prevPt = pt;
 }
 }
 
 prevPt = nextPt;
 }
 break;
 
 default:
 UNIMPLEMENTED_FOR( graphic->SHAPE_T_asString() );
 return false;
 }
 
 // Get next closest segment.
 
 PCB_SHAPE* nextGraphic = findNext( graphic, prevPt, aShapeList, aChainingEpsilon );
 
 if( nextGraphic && !( nextGraphic->GetFlags() & SKIP_STRUCT ) )
 {
 prevGraphic = graphic;
 graphic = nextGraphic;
 graphic->SetFlags( SKIP_STRUCT );
 startCandidates.erase( graphic );
 continue;
 }
 
 // Finished, or ran into trouble...
 
 if( close_enough( startPt, prevPt, aChainingEpsilon ) )
 {
 currContour.SetClosed( true );
 break;
 }
 else if( nextGraphic ) // encountered already-used segment, but not at the start
 {
 if( aErrorHandler )
 (*aErrorHandler)( _( "(self-intersecting)" ), graphic, nextGraphic, prevPt );
 
 break;
 }
 else // encountered discontinuity
 {
 if( aErrorHandler )
 (*aErrorHandler)( _( "(not a closed shape)" ), graphic, nullptr, prevPt );
 
 break;
 }
 }
 }
 }
 
 for( const SHAPE_LINE_CHAIN& contour : contours )
 {
 if( !contour.IsClosed() )
 return false;
 }
 
 // First, collect the parents of each contour
 //
 std::map<int, std::vector<int>> contourToParentIndexesMap;
 
 for( size_t ii = 0; ii < contours.size(); ++ii )
 {
 VECTOR2I firstPt = contours[ii].GetPoint( 0 );
 std::vector<int> parents;
 
 for( size_t jj = 0; jj < contours.size(); ++jj )
 {
 if( jj == ii )
 continue;
 
 const SHAPE_LINE_CHAIN& parentCandidate = contours[jj];
 
 if( parentCandidate.PointInside( firstPt ) )
 parents.push_back( jj );
 }
 
 contourToParentIndexesMap[ii] = parents;
 }
 
 // Next add those that are top-level outlines to the SHAPE_POLY_SET
 //
 std::map<int, int> contourToOutlineIdxMap;
 
 for( const auto& [ contourIndex, parentIndexes ] : contourToParentIndexesMap )
 {
 if( parentIndexes.size() %2 == 0 )
 {
 // Even number of parents; top-level outline
 if( !aAllowDisjoint && !aPolygons.IsEmpty() )
 {
 if( aErrorHandler )
 {
 BOARD_ITEM* a = fetchOwner( aPolygons.Outline( 0 ).GetSegment( 0 ) );
 BOARD_ITEM* b = fetchOwner( contours[ contourIndex ].GetSegment( 0 ) );
 
 if( a && b )
 {
 (*aErrorHandler)( _( "(multiple board outlines not supported)" ), a, b,
 contours[ contourIndex ].GetPoint( 0 ) );
 
 return false;
 }
 }
 }
 
 aPolygons.AddOutline( contours[ contourIndex ] );
 contourToOutlineIdxMap[ contourIndex ] = aPolygons.OutlineCount() - 1;
 }
 }
 
 // And finally add the holes
 //
 for( const auto& [ contourIndex, parentIndexes ] : contourToParentIndexesMap )
 {
 if( parentIndexes.size() %2 == 1 )
 {
 // Odd number of parents; we're a hole in the parent which has one fewer parents
 // than we have.
 const SHAPE_LINE_CHAIN& hole = contours[ contourIndex ];
 
 for( int parentContourIdx : parentIndexes )
 {
 if( contourToParentIndexesMap[ parentContourIdx ].size() == parentIndexes.size() - 1 )
 {
 int outlineIdx = contourToOutlineIdxMap[ parentContourIdx ];
 aPolygons.AddHole( hole, outlineIdx );
 break;
 }
 }
 }
 }
 
 // All of the silliness that follows is to work around the segment iterator while checking
 // for collisions.
 // TODO: Implement proper segment and point iterators that follow std
 
 for( auto seg1 = aPolygons.IterateSegmentsWithHoles(); seg1; seg1++ )
 {
 auto seg2 = seg1;
 
 for( ++seg2; seg2; seg2++ )
 {
 // Check for exact overlapping segments.
 if( *seg1 == *seg2 || ( ( *seg1 ).A == ( *seg2 ).B && ( *seg1 ).B == ( *seg2 ).A ) )
 {
 if( aErrorHandler )
 {
 BOARD_ITEM* a = fetchOwner( *seg1 );
 BOARD_ITEM* b = fetchOwner( *seg2 );
 (*aErrorHandler)( _( "(self-intersecting)" ), a, b, ( *seg1 ).A );
 }
 
 selfIntersecting = true;
 }
 
 if( OPT_VECTOR2I pt = seg1.Get().Intersect( seg2.Get(), true ) )
 {
 if( aErrorHandler )
 {
 BOARD_ITEM* a = fetchOwner( *seg1 );
 BOARD_ITEM* b = fetchOwner( *seg2 );
 (*aErrorHandler)( _( "(self-intersecting)" ), a, b, *pt );
 }
 
 selfIntersecting = true;
 }
 }
 }
 
 return !selfIntersecting;
}
 
 
#include <board.h>
#include <collectors.h>
 
/* This function is used to extract a board outlines (3D view, automatic zones build ...)
 * Any closed outline inside the main outline is a hole
 * All contours should be closed, i.e. valid closed polygon vertices
 */
bool BuildBoardPolygonOutlines( BOARD* aBoard, SHAPE_POLY_SET& aOutlines, int aErrorMax,
 int aChainingEpsilon, OUTLINE_ERROR_HANDLER* aErrorHandler,
 bool aAllowUseArcsInPolygons )
{
 PCB_TYPE_COLLECTOR items;
 bool success = false;
 
 SHAPE_POLY_SET fpHoles;
 
 // Get all the shapes into 'items', then keep only those on layer == Edge_Cuts.
 items.Collect( aBoard, { PCB_SHAPE_T } );
 
 for( int ii = 0; ii < items.GetCount(); ++ii )
 items[ii]->ClearFlags( SKIP_STRUCT );
 
 for( FOOTPRINT* fp : aBoard->Footprints() )
 {
 PCB_TYPE_COLLECTOR fpItems;
 fpItems.Collect( fp, { PCB_SHAPE_T } );
 
 std::vector<PCB_SHAPE*> fpSegList;
 
 for( int ii = 0; ii < fpItems.GetCount(); ii++ )
 {
 PCB_SHAPE* fpSeg = static_cast<PCB_SHAPE*>( fpItems[ii] );
 
 if( fpSeg->GetLayer() == Edge_Cuts )
 fpSegList.push_back( fpSeg );
 }
 
 if( !fpSegList.empty() )
 {
 SHAPE_POLY_SET fpOutlines;
 success = ConvertOutlineToPolygon( fpSegList, fpOutlines, aErrorMax, aChainingEpsilon,
 false,
 // don't report errors here; the second pass also
 // gets an opportunity to use these segments
 nullptr, aAllowUseArcsInPolygons );
 
 // Here, we test to see if we should make holes or outlines. Holes are made if the footprint
 // has copper outside of a single, closed outline. If there are multiple outlines, we assume
 // that the footprint edges represent holes as we do not support multiple boards. Similarly, if
 // any of the footprint pads are located outside of the edges, then the edges are holes
 if( success && ( isCopperOutside( fp, fpOutlines ) || fpOutlines.OutlineCount() > 1 ) )
 {
 fpHoles.Append( fpOutlines );
 }
 else
 {
 // If it wasn't a closed area, or wasn't a hole, the we want to keep the fpSegs
 // in contention for the board outline builds.
 for( int ii = 0; ii < fpItems.GetCount(); ++ii )
 fpItems[ii]->ClearFlags( SKIP_STRUCT );
 }
 }
 }
 
 // Make a working copy of aSegList, because the list is modified during calculations
 std::vector<PCB_SHAPE*> segList;
 
 for( int ii = 0; ii < items.GetCount(); ii++ )
 {
 PCB_SHAPE* seg = static_cast<PCB_SHAPE*>( items[ii] );
 
 // Skip anything already used to generate footprint holes (above)
 if( seg->GetFlags() & SKIP_STRUCT )
 continue;
 
 if( seg->GetLayer() == Edge_Cuts )
 segList.push_back( seg );
 }
 
 if( segList.size() )
 {
 success = ConvertOutlineToPolygon( segList, aOutlines, aErrorMax, aChainingEpsilon,
 true, aErrorHandler, aAllowUseArcsInPolygons );
 }
 
 if( !success || !aOutlines.OutlineCount() )
 {
 // Couldn't create a valid polygon outline. Use the board edge cuts bounding box to
 // create a rectangular outline, or, failing that, the bounding box of the items on
 // the board.
 
 BOX2I bbbox = aBoard->GetBoardEdgesBoundingBox();
 
 // If null area, uses the global bounding box.
 if( ( bbbox.GetWidth() ) == 0 || ( bbbox.GetHeight() == 0 ) )
 bbbox = aBoard->ComputeBoundingBox();
 
 // Ensure non null area. If happen, gives a minimal size.
 if( ( bbbox.GetWidth() ) == 0 || ( bbbox.GetHeight() == 0 ) )
 bbbox.Inflate( pcbIUScale.mmToIU( 1.0 ) );
 
 aOutlines.RemoveAllContours();
 aOutlines.NewOutline();
 
 VECTOR2I corner;
 aOutlines.Append( bbbox.GetOrigin() );
 
 corner.x = bbbox.GetOrigin().x;
 corner.y = bbbox.GetEnd().y;
 aOutlines.Append( corner );
 
 aOutlines.Append( bbbox.GetEnd() );
 
 corner.x = bbbox.GetEnd().x;
 corner.y = bbbox.GetOrigin().y;
 aOutlines.Append( corner );
 }
 
 for( int ii = 0; ii < fpHoles.OutlineCount(); ++ii )
 {
 const VECTOR2I holePt = fpHoles.Outline( ii ).CPoint( 0 );
 
 for( int jj = 0; jj < aOutlines.OutlineCount(); ++jj )
 {
 if( aOutlines.Outline( jj ).PointInside( holePt ) )
 {
 aOutlines.AddHole( fpHoles.Outline( ii ), jj );
 break;
 }
 }
 }
 
 return success;
}
 
 
void buildBoardBoundingBoxPoly( const BOARD* aBoard, SHAPE_POLY_SET& aOutline )
{
 BOX2I bbbox = aBoard->GetBoundingBox();
 SHAPE_LINE_CHAIN chain;
 
 // If null area, uses the global bounding box.
 if( ( bbbox.GetWidth() ) == 0 || ( bbbox.GetHeight() == 0 ) )
 bbbox = aBoard->ComputeBoundingBox();
 
 // Ensure non null area. If happen, gives a minimal size.
 if( ( bbbox.GetWidth() ) == 0 || ( bbbox.GetHeight() == 0 ) )
 bbbox.Inflate( pcbIUScale.mmToIU( 1.0 ) );
 
 // Inflate slightly (by 1/10th the size of the box)
 bbbox.Inflate( bbbox.GetWidth() / 10, bbbox.GetHeight() / 10 );
 
 chain.Append( bbbox.GetOrigin() );
 chain.Append( bbbox.GetOrigin().x, bbbox.GetEnd().y );
 chain.Append( bbbox.GetEnd() );
 chain.Append( bbbox.GetEnd().x, bbbox.GetOrigin().y );
 chain.SetClosed( true );
 
 aOutline.RemoveAllContours();
 aOutline.AddOutline( chain );
}
 
 
VECTOR2I projectPointOnSegment( const VECTOR2I& aEndPoint, const SHAPE_POLY_SET& aOutline,
 int aOutlineNum = 0 )
{
 int minDistance = -1;
 VECTOR2I projPoint;
 
 for( auto it = aOutline.CIterateSegments( aOutlineNum ); it; it++ )
 {
 auto seg = it.Get();
 int dis = seg.Distance( aEndPoint );
 
 if( minDistance < 0 || ( dis < minDistance ) )
 {
 minDistance = dis;
 projPoint = seg.NearestPoint( aEndPoint );
 }
 }
 
 return projPoint;
}
 
 
int findEndSegments( SHAPE_LINE_CHAIN& aChain, SEG& aStartSeg, SEG& aEndSeg )
{
 int foundSegs = 0;
 
 for( int i = 0; i < aChain.SegmentCount(); i++ )
 {
 SEG seg = aChain.Segment( i );
 
 bool foundA = false;
 bool foundB = false;
 
 for( int j = 0; j < aChain.SegmentCount(); j++ )
 {
 // Don't test the segment against itself
 if( i == j )
 continue;
 
 SEG testSeg = aChain.Segment( j );
 
 if( testSeg.Contains( seg.A ) )
 foundA = true;
 
 if( testSeg.Contains( seg.B ) )
 foundB = true;
 }
 
 // This segment isn't a start or end
 if( foundA && foundB )
 continue;
 
 if( foundSegs == 0 )
 {
 // The first segment we encounter is the "start" segment
 wxLogTrace( traceBoardOutline, wxT( "Found start segment: (%d, %d)-(%d, %d)" ),
 seg.A.x, seg.A.y, seg.B.x, seg.B.y );
 aStartSeg = seg;
 foundSegs++;
 }
 else
 {
 // Once we find both start and end, we can stop
 wxLogTrace( traceBoardOutline, wxT( "Found end segment: (%d, %d)-(%d, %d)" ),
 seg.A.x, seg.A.y, seg.B.x, seg.B.y );
 aEndSeg = seg;
 foundSegs++;
 break;
 }
 }
 
 return foundSegs;
}
 
 
bool BuildFootprintPolygonOutlines( BOARD* aBoard, SHAPE_POLY_SET& aOutlines, int aErrorMax,
 int aChainingEpsilon, OUTLINE_ERROR_HANDLER* aErrorHandler )
 
{
 FOOTPRINT* footprint = aBoard->GetFirstFootprint();
 
 // No footprint loaded
 if( !footprint )
 {
 wxLogTrace( traceBoardOutline, wxT( "No footprint found on board" ) );
 return false;
 }
 
 PCB_TYPE_COLLECTOR items;
 SHAPE_POLY_SET outlines;
 bool success = false;
 
 // Get all the SHAPEs into 'items', then keep only those on layer == Edge_Cuts.
 items.Collect( aBoard, { PCB_SHAPE_T } );
 
 // Make a working copy of aSegList, because the list is modified during calculations
 std::vector<PCB_SHAPE*> segList;
 
 for( int ii = 0; ii < items.GetCount(); ii++ )
 {
 if( items[ii]->GetLayer() == Edge_Cuts )
 segList.push_back( static_cast<PCB_SHAPE*>( items[ii] ) );
 }
 
 if( !segList.empty() )
 {
 success = ConvertOutlineToPolygon( segList, outlines, aErrorMax, aChainingEpsilon,
 true, aErrorHandler );
 }
 
 // A closed outline was found on Edge_Cuts
 if( success )
 {
 wxLogTrace( traceBoardOutline, wxT( "Closed outline found" ) );
 
 // If copper is outside a closed polygon, treat it as a hole
 // If there are multiple outlines in the footprint, they are also holes
 if( isCopperOutside( footprint, outlines ) || outlines.OutlineCount() > 1 )
 {
 wxLogTrace( traceBoardOutline, wxT( "Treating outline as a hole" ) );
 
 buildBoardBoundingBoxPoly( aBoard, aOutlines );
 
 // Copy all outlines from the conversion as holes into the new outline
 for( int i = 0; i < outlines.OutlineCount(); i++ )
 {
 SHAPE_LINE_CHAIN& out = outlines.Outline( i );
 
 if( out.IsClosed() )
 aOutlines.AddHole( out, -1 );
 
 for( int j = 0; j < outlines.HoleCount( i ); j++ )
 {
 SHAPE_LINE_CHAIN& hole = outlines.Hole( i, j );
 
 if( hole.IsClosed() )
 aOutlines.AddHole( hole, -1 );
 }
 }
 }
 // If all copper is inside, then the computed outline is the board outline
 else
 {
 wxLogTrace( traceBoardOutline, wxT( "Treating outline as board edge" ) );
 aOutlines = outlines;
 }
 
 return true;
 }
 // No board outlines were found, so use the bounding box
 else if( outlines.OutlineCount() == 0 )
 {
 wxLogTrace( traceBoardOutline, wxT( "Using footprint bounding box" ) );
 buildBoardBoundingBoxPoly( aBoard, aOutlines );
 
 return true;
 }
 // There is an outline present, but it is not closed
 else
 {
 wxLogTrace( traceBoardOutline, wxT( "Trying to build outline" ) );
 
 std::vector<SHAPE_LINE_CHAIN> closedChains;
 std::vector<SHAPE_LINE_CHAIN> openChains;
 
 // The ConvertOutlineToPolygon function returns only one main outline and the rest as
 // holes, so we promote the holes and process them
 openChains.push_back( outlines.Outline( 0 ) );
 
 for( int j = 0; j < outlines.HoleCount( 0 ); j++ )
 {
 SHAPE_LINE_CHAIN hole = outlines.Hole( 0, j );
 
 if( hole.IsClosed() )
 {
 wxLogTrace( traceBoardOutline, wxT( "Found closed hole" ) );
 closedChains.push_back( hole );
 }
 else
 {
 wxLogTrace( traceBoardOutline, wxT( "Found open hole" ) );
 openChains.push_back( hole );
 }
 }
 
 SHAPE_POLY_SET bbox;
 buildBoardBoundingBoxPoly( aBoard, bbox );
 
 // Treat the open polys as the board edge
 SHAPE_LINE_CHAIN chain = openChains[0];
 SHAPE_LINE_CHAIN rect = bbox.Outline( 0 );
 
 // We know the outline chain is open, so set to non-closed to get better segment count
 chain.SetClosed( false );
 
 SEG startSeg;
 SEG endSeg;
 
 // The two possible board outlines
 SHAPE_LINE_CHAIN upper;
 SHAPE_LINE_CHAIN lower;
 
 findEndSegments( chain, startSeg, endSeg );
 
 if( chain.SegmentCount() == 0 )
 {
 // Something is wrong, bail out with the overall footprint bounding box
 wxLogTrace( traceBoardOutline, wxT( "No line segments in provided outline" ) );
 aOutlines = bbox;
 return true;
 }
 else if( chain.SegmentCount() == 1 )
 {
 // This case means there is only 1 line segment making up the edge cuts of the
 // footprint, so we just need to use it to cut the bounding box in half.
 wxLogTrace( traceBoardOutline, wxT( "Only 1 line segment in provided outline" ) );
 
 startSeg = chain.Segment( 0 );
 
 // Intersect with all the sides of the rectangle
 OPT_VECTOR2I inter0 = startSeg.IntersectLines( rect.Segment( 0 ) );
 OPT_VECTOR2I inter1 = startSeg.IntersectLines( rect.Segment( 1 ) );
 OPT_VECTOR2I inter2 = startSeg.IntersectLines( rect.Segment( 2 ) );
 OPT_VECTOR2I inter3 = startSeg.IntersectLines( rect.Segment( 3 ) );
 
 if( inter0 && inter2 && !inter1 && !inter3 )
 {
 // Intersects the vertical rectangle sides only
 wxLogTrace( traceBoardOutline, wxT( "Segment intersects only vertical bbox "
 "sides" ) );
 
 // The upper half
 upper.Append( *inter0 );
 upper.Append( rect.GetPoint( 1 ) );
 upper.Append( rect.GetPoint( 2 ) );
 upper.Append( *inter2 );
 upper.SetClosed( true );
 
 // The lower half
 lower.Append( *inter0 );
 lower.Append( rect.GetPoint( 0 ) );
 lower.Append( rect.GetPoint( 3 ) );
 lower.Append( *inter2 );
 lower.SetClosed( true );
 }
 else if( inter1 && inter3 && !inter0 && !inter2 )
 {
 // Intersects the horizontal rectangle sides only
 wxLogTrace( traceBoardOutline, wxT( "Segment intersects only horizontal bbox "
 "sides" ) );
 
 // The left half
 upper.Append( *inter1 );
 upper.Append( rect.GetPoint( 1 ) );
 upper.Append( rect.GetPoint( 0 ) );
 upper.Append( *inter3 );
 upper.SetClosed( true );
 
 // The right half
 lower.Append( *inter1 );
 lower.Append( rect.GetPoint( 2 ) );
 lower.Append( rect.GetPoint( 3 ) );
 lower.Append( *inter3 );
 lower.SetClosed( true );
 }
 else
 {
 // Angled line segment that cuts across a corner
 wxLogTrace( traceBoardOutline, wxT( "Segment intersects two perpendicular bbox "
 "sides" ) );
 
 // Figure out which actual lines are intersected, since IntersectLines assumes
 // an infinite line
 bool hit0 = rect.Segment( 0 ).Contains( *inter0 );
 bool hit1 = rect.Segment( 1 ).Contains( *inter1 );
 bool hit2 = rect.Segment( 2 ).Contains( *inter2 );
 bool hit3 = rect.Segment( 3 ).Contains( *inter3 );
 
 if( hit0 && hit1 )
 {
 // Cut across the upper left corner
 wxLogTrace( traceBoardOutline, wxT( "Segment cuts upper left corner" ) );
 
 // The upper half
 upper.Append( *inter0 );
 upper.Append( rect.GetPoint( 1 ) );
 upper.Append( *inter1 );
 upper.SetClosed( true );
 
 // The lower half
 lower.Append( *inter0 );
 lower.Append( rect.GetPoint( 0 ) );
 lower.Append( rect.GetPoint( 3 ) );
 lower.Append( rect.GetPoint( 2 ) );
 lower.Append( *inter1 );
 lower.SetClosed( true );
 }
 else if( hit1 && hit2 )
 {
 // Cut across the upper right corner
 wxLogTrace( traceBoardOutline, wxT( "Segment cuts upper right corner" ) );
 
 // The upper half
 upper.Append( *inter1 );
 upper.Append( rect.GetPoint( 2 ) );
 upper.Append( *inter2 );
 upper.SetClosed( true );
 
 // The lower half
 lower.Append( *inter1 );
 lower.Append( rect.GetPoint( 1 ) );
 lower.Append( rect.GetPoint( 0 ) );
 lower.Append( rect.GetPoint( 3 ) );
 lower.Append( *inter2 );
 lower.SetClosed( true );
 }
 else if( hit2 && hit3 )
 {
 // Cut across the lower right corner
 wxLogTrace( traceBoardOutline, wxT( "Segment cuts lower right corner" ) );
 
 // The upper half
 upper.Append( *inter2 );
 upper.Append( rect.GetPoint( 2 ) );
 upper.Append( rect.GetPoint( 1 ) );
 upper.Append( rect.GetPoint( 0 ) );
 upper.Append( *inter3 );
 upper.SetClosed( true );
 
 // The bottom half
 lower.Append( *inter2 );
 lower.Append( rect.GetPoint( 3 ) );
 lower.Append( *inter3 );
 lower.SetClosed( true );
 }
 else
 {
 // Cut across the lower left corner
 wxLogTrace( traceBoardOutline, wxT( "Segment cuts upper left corner" ) );
 
 // The upper half
 upper.Append( *inter0 );
 upper.Append( rect.GetPoint( 1 ) );
 upper.Append( rect.GetPoint( 2 ) );
 upper.Append( rect.GetPoint( 3 ) );
 upper.Append( *inter3 );
 upper.SetClosed( true );
 
 // The bottom half
 lower.Append( *inter0 );
 lower.Append( rect.GetPoint( 0 ) );
 lower.Append( *inter3 );
 lower.SetClosed( true );
 }
 }
 }
 else
 {
 // More than 1 segment
 wxLogTrace( traceBoardOutline, wxT( "Multiple segments in outline" ) );
 
 // Just a temporary thing
 aOutlines = bbox;
 return true;
 }
 
 // Figure out which is the correct outline
 SHAPE_POLY_SET poly1;
 SHAPE_POLY_SET poly2;
 
 poly1.NewOutline();
 poly1.Append( upper );
 
 poly2.NewOutline();
 poly2.Append( lower );
 
 if( isCopperOutside( footprint, poly1 ) )
 {
 wxLogTrace( traceBoardOutline, wxT( "Using lower shape" ) );
 aOutlines = poly2;
 }
 else
 {
 wxLogTrace( traceBoardOutline, wxT( "Using upper shape" ) );
 aOutlines = poly1;
 }
 
 // Add all closed polys as holes to the main outline
 for( SHAPE_LINE_CHAIN& closedChain : closedChains )
 {
 wxLogTrace( traceBoardOutline, wxT( "Adding hole to main outline" ) );
 aOutlines.AddHole( closedChain, -1 );
 }
 
 return true;
 }
 
 // We really shouldn't reach this point
 return false;
}