kicad/polygon/PolyLine.cpp

/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Few parts of this code come from FreePCB, released under the GNU General Public License V2.
 * (see http://www.freepcb.com/ )
 *
 * Copyright (C) 2012-2015 Jean-Pierre Charras, jp.charras at wanadoo.fr
 * Copyright (C) 2012-2015 KiCad Developers, see CHANGELOG.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
 */

/**
 * @file PolyLine.cpp
 * @note implementation of CPolyLine class
 */

//
// implementation for kicad, using clipper polygon clipping library
// for transformations not handled (at least for Kicad) by boost::polygon
//
#include <cmath>
#include <vector>
#include <algorithm>

#include <fctsys.h>
#include <common.h>     // KiROUND

#include <PolyLine.h>
#include <bezier_curves.h>
#include <polygon_test_point_inside.h>
#include <math_for_graphics.h>
#include <polygon_test_point_inside.h>


CPolyLine::CPolyLine()
{
    m_hatchStyle = NO_HATCH;
    m_hatchPitch = 0;
    m_layer      = F_Cu;
    m_flags    = 0;
}

CPolyLine::CPolyLine( const CPolyLine& aCPolyLine)
{
    Copy( &aCPolyLine );
    m_HatchLines    = aCPolyLine.m_HatchLines;     // vector <> copy
}


// destructor, removes display elements
//
CPolyLine::~CPolyLine()
{
    UnHatch();
}


/*
 * Removes corners which create a null segment edge
 * (i.e. when 2 successive corners are at the same location)
 * returns the count of removed corners.
 */
int CPolyLine::RemoveNullSegments()
{
    int removed = 0;
    unsigned startcountour = 0;

    for( unsigned icnt = 1; icnt < m_CornersList.GetCornersCount(); icnt ++ )
    {
        unsigned last = icnt-1;
        if( m_CornersList[icnt].end_contour )
        {
            last = startcountour;
            startcountour = icnt+1;
        }

        if( ( m_CornersList[last].x == m_CornersList[icnt].x ) &&
            ( m_CornersList[last].y == m_CornersList[icnt].y ) )
        {
            DeleteCorner( icnt );
            icnt--;
            removed ++;
        }

        if( m_CornersList[icnt].end_contour )
        {
            startcountour = icnt+1;
            icnt++;
        }
    }

    return removed;
}


/* Convert a self-intersecting polygon to one (or more) non self-intersecting polygon(s)
 * and removes null segments.
 * param aNewPolygonList = a std::vector<CPolyLine*> reference where to store new CPolyLine
 * needed by the normalization
 * return the polygon count (always >= 1, because there is at least one polygon)
 * There are new polygons only if the polygon count  is > 1
 */
int CPolyLine::NormalizeAreaOutlines( std::vector<CPolyLine*>* aNewPolygonList )
{
    SHAPE_POLY_SET polySet = ConvertPolyListToPolySet( m_CornersList );

    // We are expecting only one main outline, but this main outline can have holes
    // if holes: combine holes and remove them from the main outline.
    // Note also we are using SHAPE_POLY_SET::PM_STRICTLY_SIMPLE in polygon
    // calculations, but it is not mandatory. It is used mainly
    // because there is usually only very few vertices in area outlines
    SHAPE_POLY_SET::POLYGON& outline = polySet.Polygon( 0 );
    SHAPE_POLY_SET holesBuffer;

    // Move holes stored in outline to holesBuffer:
    // The first SHAPE_LINE_CHAIN is the main outline, others are holes
    while( outline.size() > 1 )
    {
        holesBuffer.AddOutline( outline.back() );
        outline.pop_back();
    }

    polySet.Simplify( SHAPE_POLY_SET::PM_STRICTLY_SIMPLE);

    // If any hole, substract it to main outline
    if( holesBuffer.OutlineCount() )
    {
        holesBuffer.Simplify( SHAPE_POLY_SET::PM_FAST);
        polySet.BooleanSubtract( holesBuffer, SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );
    }

    RemoveAllContours();

    // Note: we can have more than outline, because a self intersecting outline will be
    // broken to non intersecting polygons, and removing holes can also create a few polygons
    for( int ii = 0; ii < polySet.OutlineCount(); ii++ )
    {
        CPolyLine* polyline = this;

        if( ii > 0 )
        {
            polyline = new CPolyLine;
            polyline->ImportSettings( this );
            aNewPolygonList->push_back( polyline );
        }

        SHAPE_POLY_SET pnew;
        pnew.NewOutline();
        pnew.Polygon( 0 ) = polySet.CPolygon( ii );

        polyline->m_CornersList = ConvertPolySetToPolyList( pnew );
        polyline->RemoveNullSegments();
    }

    return polySet.OutlineCount();
}


/**
 * Function ImportSettings
 * Copy settings (layer, hatch styles) from aPoly
 */
void CPolyLine::ImportSettings( const CPolyLine * aPoly )
{
    SetLayer( aPoly->GetLayer() );
    SetHatchStyle( aPoly->GetHatchStyle() );
    SetHatchPitch( aPoly->GetHatchPitch() );
}


/* initialize a contour
 * set layer, hatch style, and starting point
 */
void CPolyLine::Start( LAYER_NUM layer, int x, int y, int hatch )
{
    m_layer = layer;
    SetHatchStyle( (enum HATCH_STYLE) hatch );
    CPolyPt poly_pt( x, y );
    poly_pt.end_contour = false;

    m_CornersList.Append( poly_pt );
}


// add a corner to unclosed polyline
//
void CPolyLine::AppendCorner( int x, int y )
{
    UnHatch();
    CPolyPt poly_pt( x, y );
    poly_pt.end_contour = false;

    // add entries for new corner
    m_CornersList.Append( poly_pt );
}


// move corner of polyline
//
void CPolyLine::MoveCorner( int ic, int x, int y )
{
    UnHatch();
    m_CornersList[ic].x = x;
    m_CornersList[ic].y = y;
    Hatch();
}


// delete corner and adjust arrays
//
void CPolyLine::DeleteCorner( int ic )
{
    UnHatch();
    int     icont   = GetContour( ic );
    int     iend    = GetContourEnd( icont );
    bool    closed = icont < GetContoursCount() - 1 || GetClosed();

    if( !closed )
    {
        // open contour, must be last contour
        m_CornersList.DeleteCorner( ic );
    }
    else
    {
        // closed contour
        m_CornersList.DeleteCorner( ic );

        if( ic == iend )
            m_CornersList[ic - 1].end_contour = true;
    }

    if( closed && GetContourSize( icont ) < 3 )
    {
        // delete the entire contour
        RemoveContour( icont );
    }
}


/**
 * Function RemoveContour
 * @param icont = contour number to remove
 * remove a contour only if there is more than 1 contour
 */
void CPolyLine::RemoveContour( int icont )
{
    UnHatch();
    int istart  = GetContourStart( icont );
    int iend    = GetContourEnd( icont );

    int polycount = GetContoursCount();

    if( icont == 0 && polycount == 1 )
    {
        // remove the only contour
        wxASSERT( 0 );
    }
    else
    {
        // remove closed contour
        for( int ic = iend; ic>=istart; ic-- )
        {
            m_CornersList.DeleteCorner( ic );
        }
    }

    Hatch();
}


CPolyLine* CPolyLine::Chamfer( unsigned int aDistance )
{
    // Null segments create serious issues in calculations.
    // remove them:
    RemoveNullSegments();

    CPolyLine* newPoly = new CPolyLine;

    if( !aDistance )
    {
        newPoly->Copy( this );
        return newPoly;
    }

    int polycount = GetContoursCount();

    for( int contour = 0; contour < polycount; contour++ )
    {
        unsigned int    startIndex  = GetContourStart( contour );
        unsigned int    endIndex    = GetContourEnd( contour );

        for( unsigned int index = startIndex; index <= endIndex; index++ )
        {
            // Current vertex
            int     x1  = m_CornersList[index].x;
            int     y1  = m_CornersList[index].y;
            double  xa, ya;     // Previous vertex
            double  xb, yb;     // Next vertex

            if( index == startIndex )
            {
                xa  = m_CornersList[endIndex].x - x1;
                ya  = m_CornersList[endIndex].y - y1;
            }
            else
            {
                xa  = m_CornersList[index - 1].x - x1;
                ya  = m_CornersList[index - 1].y - y1;
            }

            if( index == endIndex )
            {
                xb  = m_CornersList[startIndex].x - x1;
                yb  = m_CornersList[startIndex].y - y1;
            }
            else
            {
                xb  = m_CornersList[index + 1].x - x1;
                yb  = m_CornersList[index + 1].y - y1;
            }

            double  lena = hypot( xa, ya );
            double  lenb = hypot( xb, yb );
            double      distance    = aDistance;

            // Chamfer one half of an edge at most
            if( 0.5 * lena < distance )
                distance = 0.5 * lena;

            if( 0.5 * lenb < distance )
                distance = 0.5 * lenb;

            int nx1  = KiROUND( distance * xa / lena );
            int ny1  = KiROUND( distance * ya / lena );

            if( index == startIndex )
                newPoly->Start( GetLayer(), x1 + nx1, y1 + ny1, GetHatchStyle() );
            else
                newPoly->AppendCorner( x1 + nx1, y1 + ny1 );

            int nx2  = KiROUND( distance * xb / lenb );
            int ny2  = KiROUND( distance * yb / lenb );

            // Due to rounding errors, repeated corners could be added; this check prevents it
            if(nx1 != nx2 || ny1 != ny2)
                newPoly->AppendCorner( x1 + nx2, y1 + ny2 );
        }

        newPoly->CloseLastContour();
    }

    return newPoly;
}


CPolyLine* CPolyLine::Fillet( unsigned int aRadius, unsigned int aSegments )
{
    // Null segments create serious issues in calculations.
    // remove them:
    RemoveNullSegments();

    CPolyLine* newPoly = new CPolyLine;

    if( !aRadius )
    {
        newPoly->Copy( this );
        return newPoly;
    }

    int polycount = GetContoursCount();

    for( int contour = 0; contour < polycount; contour++ )
    {
        unsigned int    startIndex  = GetContourStart( contour );
        unsigned int    endIndex    = GetContourEnd( contour );

        for( unsigned int index = startIndex; index <= endIndex; index++ )
        {
            // Current vertex
            int     x1  = m_CornersList[index].x;
            int     y1  = m_CornersList[index].y;
            double  xa, ya; // Previous vertex
            double  xb, yb; // Next vertex

            if( index == startIndex )
            {
                xa  = m_CornersList[endIndex].x - x1;
                ya  = m_CornersList[endIndex].y - y1;
            }
            else
            {
                xa  = m_CornersList[index - 1].x - x1;
                ya  = m_CornersList[index - 1].y - y1;
            }

            if( index == endIndex )
            {
                xb  = m_CornersList[startIndex].x - x1;
                yb  = m_CornersList[startIndex].y - y1;
            }
            else
            {
                xb  = m_CornersList[index + 1].x - x1;
                yb  = m_CornersList[index + 1].y - y1;
            }

            double          lena    = hypot( xa, ya );
            double          lenb    = hypot( xb, yb );
            double          cosine  = ( xa * xb + ya * yb ) / ( lena * lenb );

            double          radius  = aRadius;
            double          denom   = sqrt( 2.0 / ( 1 + cosine ) - 1 );

            // Do nothing in case of parallel edges
            if( std::isinf( denom ) )
                continue;

            // Limit rounding distance to one half of an edge
            if( 0.5 * lena * denom < radius )
                radius = 0.5 * lena * denom;

            if( 0.5 * lenb * denom < radius )
                radius = 0.5 * lenb * denom;

            // Calculate fillet arc absolute center point (xc, yx)
            double  k       = radius / sqrt( .5 * ( 1 - cosine ) );
            double  lenab   = sqrt( ( xa / lena + xb / lenb ) * ( xa / lena + xb / lenb ) +
                                    ( ya / lena + yb / lenb ) * ( ya / lena + yb / lenb ) );
            double  xc  = x1 + k * ( xa / lena + xb / lenb ) / lenab;
            double  yc  = y1 + k * ( ya / lena + yb / lenb ) / lenab;

            // Calculate arc start and end vectors
            k = radius / sqrt( 2 / ( 1 + cosine ) - 1 );
            double  xs  = x1 + k * xa / lena - xc;
            double  ys  = y1 + k * ya / lena - yc;
            double  xe  = x1 + k * xb / lenb - xc;
            double  ye  = y1 + k * yb / lenb - yc;

            // Cosine of arc angle
            double  argument = ( xs * xe + ys * ye ) / ( radius * radius );

            if( argument < -1 ) // Just in case...
                argument = -1;
            else if( argument > 1 )
                argument = 1;

            double  arcAngle = acos( argument );

            // Calculate the number of segments
            double  tempSegments = (double) aSegments * ( arcAngle / ( 2 * M_PI ) );

            if( tempSegments - (int) tempSegments > 0 )
                tempSegments++;

            unsigned int    segments = (unsigned int) tempSegments;

            double          deltaAngle  = arcAngle / segments;
            double          startAngle  = atan2( -ys, xs );

            // Flip arc for inner corners
            if( xa * yb - ya * xb <= 0 )
                deltaAngle *= -1;

            double nx  = xc + xs;
            double ny  = yc + ys;

            if( index == startIndex )
                newPoly->Start( GetLayer(), KiROUND( nx ), KiROUND( ny ), GetHatchStyle() );
            else
                newPoly->AppendCorner( KiROUND( nx ), KiROUND( ny ) );

            // Store the previous added corner to make a sanity check
            int prevX = KiROUND(nx);
            int prevY = KiROUND(ny);

            for( unsigned int j = 0; j < segments; j++ )
            {
                nx  = xc + cos( startAngle + (j + 1) * deltaAngle ) * radius;
                ny  = yc - sin( startAngle + (j + 1) * deltaAngle ) * radius;

                // Due to rounding errors, repeated corners could be added; this check prevents it
                if(KiROUND(nx) != prevX || KiROUND(ny) != prevY)
                {
                    newPoly->AppendCorner( KiROUND( nx ), KiROUND( ny ) );
                    prevX = KiROUND(nx);
                    prevY = KiROUND(ny);
                }
            }
        }

        newPoly->CloseLastContour();
    }

    return newPoly;
}


/**
 * function RemoveAllContours
 * removes all corners from the list.
 * Others params are not changed
 */
void CPolyLine::RemoveAllContours()
{
    m_CornersList.RemoveAllContours();
}


/**
 * Function InsertCorner
 * insert a new corner between two existing corners
 * @param ic = index for the insertion point: the corner is inserted AFTER ic
 * @param x, y = coordinates corner to insert
 */
void CPolyLine::InsertCorner( int ic, int x, int y )
{
    UnHatch();

    if( (unsigned) (ic) >= m_CornersList.GetCornersCount() )
    {
        m_CornersList.Append( CPolyPt( x, y ) );
    }
    else
    {
        m_CornersList.InsertCorner(ic, CPolyPt( x, y ) );
    }

    if( (unsigned) (ic + 1) < m_CornersList.GetCornersCount() )
    {
        if( m_CornersList[ic].end_contour )
        {
            m_CornersList[ic + 1].end_contour   = true;
            m_CornersList[ic].end_contour       = false;
        }
    }

    Hatch();
}


// undraw polyline by removing all graphic elements from display list
void CPolyLine::UnHatch()
{
    m_HatchLines.clear();
}


const EDA_RECT CPolyLine::GetBoundingBox()
{
    int xmin    = INT_MAX;
    int ymin    = INT_MAX;
    int xmax    = INT_MIN;
    int ymax    = INT_MIN;

    for( unsigned i = 0; i< m_CornersList.GetCornersCount(); i++ )
    {
        xmin    = std::min( xmin, m_CornersList[i].x );
        xmax    = std::max( xmax, m_CornersList[i].x );
        ymin    = std::min( ymin, m_CornersList[i].y );
        ymax    = std::max( ymax, m_CornersList[i].y );
    }

    EDA_RECT r;
    r.SetOrigin( wxPoint( xmin, ymin ) );
    r.SetEnd( wxPoint( xmax, ymax ) );

    return r;
}


const EDA_RECT CPolyLine::GetBoundingBox( int icont )
{
    int xmin    = INT_MAX;
    int ymin    = INT_MAX;
    int xmax    = INT_MIN;
    int ymax    = INT_MIN;
    int istart  = GetContourStart( icont );
    int iend    = GetContourEnd( icont );

    for( int i = istart; i<=iend; i++ )
    {
        xmin    = std::min( xmin, m_CornersList[i].x );
        xmax    = std::max( xmax, m_CornersList[i].x );
        ymin    = std::min( ymin, m_CornersList[i].y );
        ymax    = std::max( ymax, m_CornersList[i].y );
    }

    EDA_RECT r;
    r.SetOrigin( wxPoint( xmin, ymin ) );
    r.SetEnd( wxPoint( xmax, ymax ) );

    return r;
}


int CPolyLine::GetContoursCount() const
{
    return m_CornersList.GetContoursCount();
}



int CPOLYGONS_LIST::GetContoursCount() const
{
    if( !m_cornersList.size() )
        return 0;

    // count the number of corners flagged end_contour
    int ncont = 0;

    for( unsigned ic = 0; ic < m_cornersList.size(); ic++ )
        if( m_cornersList[ic].end_contour )
            ncont++;

    // The last corner can be not yet flagged end_contour.
    // It was not counted, but the polygon exists, so count it
    if( !m_cornersList[m_cornersList.size() - 1].end_contour )
        ncont++;

    return ncont;
}


int CPolyLine::GetContour( int ic )
{
    int ncont = 0;

    for( int i = 0; i<ic; i++ )
    {
        if( m_CornersList[i].end_contour )
            ncont++;
    }

    return ncont;
}


int CPolyLine::GetContourStart( int icont )
{
    if( icont == 0 )
        return 0;

    int ncont = 0;

    for( unsigned i = 0; i<m_CornersList.GetCornersCount(); i++ )
    {
        if( m_CornersList[i].end_contour )
        {
            ncont++;

            if( ncont == icont )
                return i + 1;
        }
    }

    wxASSERT( 0 );
    return 0;
}


int CPolyLine::GetContourEnd( int icont )
{
    if( icont < 0 )
        return 0;

    if( icont == GetContoursCount() - 1 )
        return m_CornersList.GetCornersCount() - 1;

    int ncont = 0;

    for( unsigned i = 0; i<m_CornersList.GetCornersCount(); i++ )
    {
        if( m_CornersList[i].end_contour )
        {
            if( ncont == icont )
                return i;

            ncont++;
        }
    }

    wxASSERT( 0 );
    return 0;
}


int CPolyLine::GetContourSize( int icont )
{
    return GetContourEnd( icont ) - GetContourStart( icont ) + 1;
}


bool CPolyLine::GetClosed()
{
    if( m_CornersList.GetCornersCount() == 0 )
        return false;
    else
        return m_CornersList[m_CornersList.GetCornersCount() - 1].end_contour;
}


// Creates hatch lines inside the outline of the complex polygon
//
// sort function used in ::Hatch to sort points by descending wxPoint.x values
bool sort_ends_by_descending_X( const wxPoint& ref, const wxPoint& tst )
{
    return tst.x < ref.x;
}


void CPolyLine::Hatch()
{
    m_HatchLines.clear();

    if( m_hatchStyle == NO_HATCH || m_hatchPitch == 0 )
        return;

    if( !GetClosed() ) // If not closed, the poly is beeing created and not finalised. Not not hatch
        return;

    // define range for hatch lines
    int min_x   = m_CornersList[0].x;
    int max_x   = m_CornersList[0].x;
    int min_y   = m_CornersList[0].y;
    int max_y   = m_CornersList[0].y;

    for( unsigned ic = 1; ic < m_CornersList.GetCornersCount(); ic++ )
    {
        if( m_CornersList[ic].x < min_x )
            min_x = m_CornersList[ic].x;

        if( m_CornersList[ic].x > max_x )
            max_x = m_CornersList[ic].x;

        if( m_CornersList[ic].y < min_y )
            min_y = m_CornersList[ic].y;

        if( m_CornersList[ic].y > max_y )
            max_y = m_CornersList[ic].y;
    }

    // Calculate spacing between 2 hatch lines
    int spacing;

    if( m_hatchStyle == DIAGONAL_EDGE )
        spacing = m_hatchPitch;
    else
        spacing = m_hatchPitch * 2;

    // set the "length" of hatch lines (the length on horizontal axis)
    double  hatch_line_len = m_hatchPitch;

    // To have a better look, give a slope depending on the layer
    LAYER_NUM layer = GetLayer();
    int     slope_flag = (layer & 1) ? 1 : -1;  // 1 or -1
    double  slope = 0.707106 * slope_flag;      // 45 degrees slope
    int     max_a, min_a;

    if( slope_flag == 1 )
    {
        max_a   = KiROUND( max_y - slope * min_x );
        min_a   = KiROUND( min_y - slope * max_x );
    }
    else
    {
        max_a   = KiROUND( max_y - slope * max_x );
        min_a   = KiROUND( min_y - slope * min_x );
    }

    min_a = (min_a / spacing) * spacing;

    // calculate an offset depending on layer number,
    // for a better look of hatches on a multilayer board
    int offset = (layer * 7) / 8;
    min_a += offset;

    // now calculate and draw hatch lines
    int nc = m_CornersList.GetCornersCount();

    // loop through hatch lines
    #define MAXPTS 200      // Usually we store only few values per one hatch line
                            // depending on the compexity of the zone outline

    static std::vector <wxPoint> pointbuffer;
    pointbuffer.clear();
    pointbuffer.reserve( MAXPTS + 2 );

    for( int a = min_a; a < max_a; a += spacing )
    {
        // get intersection points for this hatch line

        // Note: because we should have an even number of intersections with the
        // current hatch line and the zone outline (a closed polygon,
        // or a set of closed polygons), if an odd count is found
        // we skip this line (should not occur)
        pointbuffer.clear();
        int i_start_contour = 0;

        for( int ic = 0; ic<nc; ic++ )
        {
            double  x, y, x2, y2;
            int     ok;

            if( m_CornersList[ic].end_contour ||
                ( ic == (int) (m_CornersList.GetCornersCount() - 1) ) )
            {
                ok = FindLineSegmentIntersection( a, slope,
                                                  m_CornersList[ic].x, m_CornersList[ic].y,
                                                  m_CornersList[i_start_contour].x,
                                                  m_CornersList[i_start_contour].y,
                                                  &x, &y, &x2, &y2 );
                i_start_contour = ic + 1;
            }
            else
            {
                ok = FindLineSegmentIntersection( a, slope,
                                                  m_CornersList[ic].x, m_CornersList[ic].y,
                                                  m_CornersList[ic + 1].x, m_CornersList[ic + 1].y,
                                                  &x, &y, &x2, &y2 );
            }

            if( ok )
            {
                wxPoint point( KiROUND( x ), KiROUND( y ) );
                pointbuffer.push_back( point );
            }

            if( ok == 2 )
            {
                wxPoint point( KiROUND( x2 ), KiROUND( y2 ) );
                pointbuffer.push_back( point );
            }

            if( pointbuffer.size() >= MAXPTS )    // overflow
            {
                wxASSERT( 0 );
                break;
            }
        }

        // ensure we have found an even intersection points count
        // because intersections are the ends of segments
        // inside the polygon(s) and a segment has 2 ends.
        // if not, this is a strange case (a bug ?) so skip this hatch
        if( pointbuffer.size() % 2 != 0 )
            continue;

        // sort points in order of descending x (if more than 2) to
        // ensure the starting point and the ending point of the same segment
        // are stored one just after the other.
        if( pointbuffer.size() > 2 )
            sort( pointbuffer.begin(), pointbuffer.end(), sort_ends_by_descending_X );

        // creates lines or short segments inside the complex polygon
        for( unsigned ip = 0; ip < pointbuffer.size(); ip += 2 )
        {
            double dx = pointbuffer[ip + 1].x - pointbuffer[ip].x;

            // Push only one line for diagonal hatch,
            // or for small lines < twice the line len
            // else push 2 small lines
            if( m_hatchStyle == DIAGONAL_FULL || fabs( dx ) < 2 * hatch_line_len )
            {
                m_HatchLines.push_back( CSegment( pointbuffer[ip], pointbuffer[ip + 1] ) );
            }
            else
            {
                double dy = pointbuffer[ip + 1].y - pointbuffer[ip].y;
                slope = dy / dx;

                if( dx > 0 )
                    dx = hatch_line_len;
                else
                    dx = -hatch_line_len;

                double  x1  = pointbuffer[ip].x + dx;
                double  x2  = pointbuffer[ip + 1].x - dx;
                double  y1  = pointbuffer[ip].y + dx * slope;
                double  y2  = pointbuffer[ip + 1].y - dx * slope;

                m_HatchLines.push_back( CSegment( pointbuffer[ip].x,
                                                  pointbuffer[ip].y,
                                                  KiROUND( x1 ), KiROUND( y1 ) ) );

                m_HatchLines.push_back( CSegment( pointbuffer[ip + 1].x,
                                                  pointbuffer[ip + 1].y,
                                                  KiROUND( x2 ), KiROUND( y2 ) ) );
            }
        }
    }
}


// test to see if a point is inside polyline
//
bool CPolyLine::TestPointInside( int px, int py )
{
    if( !GetClosed() )
    {
        wxASSERT( 0 );
    }

    // Test all polygons.
    // Since the first is the main outline, and other are holes,
    // if the tested point is inside only one contour, it is inside the whole polygon
    // (in fact inside the main outline, and outside all holes).
    // if inside 2 contours (the main outline + an hole), it is outside the poly.
    int     polycount   = GetContoursCount();
    bool    inside      = false;

    for( int icont = 0; icont < polycount; icont++ )
    {
        int istart  = GetContourStart( icont );
        int iend    = GetContourEnd( icont );

         // test point inside the current polygon
        if( TestPointInsidePolygon( m_CornersList, istart, iend, px, py ) )
            inside = not inside;
    }

    return inside;
}


// copy data from another CPolyLine, but don't draw it
void CPolyLine::Copy( const CPolyLine* src )
{
    UnHatch();
    m_layer         = src->m_layer;
    m_hatchStyle    = src->m_hatchStyle;
    m_hatchPitch    = src->m_hatchPitch;
    m_flags         = src->m_flags;
    m_CornersList.RemoveAllContours();
    m_CornersList.Append( src->m_CornersList );
}


/*
 * return true if the corner aCornerIdx is on a hole inside the main outline
 * and false if it is on the main outline
 */
bool CPolyLine::IsCutoutContour( int aCornerIdx )
{
    int ncont = GetContour( aCornerIdx );

    if( ncont == 0 ) // the first contour is the main outline, not an hole
        return false;

    return true;
}


void CPolyLine::MoveOrigin( int x_off, int y_off )
{
    UnHatch();

    for( int ic = 0; ic < GetCornersCount(); ic++ )
    {
        SetX( ic, GetX( ic ) + x_off );
        SetY( ic, GetY( ic ) + y_off );
    }

    Hatch();
}


/*
 * AppendArc:
 * adds segments to current contour to approximate the given arc
 */
void CPolyLine::AppendArc( int xi, int yi, int xf, int yf, int xc, int yc, int num )
{
    // get radius
    double  radius  = ::Distance( xi, yi, xf, yf );

    // get angles of start pint and end point
    double  th_i    = atan2( (double) (yi - yc), (double) (xi - xc) );
    double  th_f    = atan2( (double) (yf - yc), (double) (xf - xc) );
    double  th_d    = (th_f - th_i) / (num - 1);
    double  theta   = th_i;

    // generate arc
    for( int ic = 0; ic < num; ic++ )
    {
        int x   = xc + KiROUND( radius * cos( theta ) );
        int y   = yc + KiROUND( radius * sin( theta ) );
        AppendCorner( x, y );
        theta += th_d;
    }

    CloseLastContour();
}


void CPolyLine::AppendBezier( int x1, int y1, int x2, int y2, int x3, int y3 )
{
    std::vector<wxPoint> polyPoints;

    BEZIER_POLY converter( x1, y1, x2, y2, x3, y3 );
    converter.GetPoly( polyPoints );

    for( const auto& pt : polyPoints )
        AppendCorner( pt.x, pt.y );
}


void CPolyLine::AppendBezier( int x1, int y1, int x2, int y2, int x3, int y3, int x4, int y4 )
{
    std::vector<wxPoint> polyPoints;

    BEZIER_POLY converter( x1, y1, x2, y2, x3, y3, x4, y4 );
    converter.GetPoly( polyPoints );

    for( const auto& pt : polyPoints )
        AppendCorner( pt.x, pt.y );
}


/*
 * Function Distance
 * Calculates the distance between a segment and a polygon (with holes):
 * param aStart is the starting point of the segment.
 * param aEnd is the ending point of the segment.
 * param aWidth is the width of the segment.
 * return distance between the segment and outline.
 *               0 if segment intersects or is inside
 */
int CPolyLine::Distance( wxPoint aStart, wxPoint aEnd, int aWidth )
{
    // We calculate the min dist between the segment and each outline segment
    // However, if the segment to test is inside the outline, and does not cross
    // any edge, it can be seen outside the polygon.
    // Therefore test if a segment end is inside ( testing only one end is enough )
    if( TestPointInside( aStart.x, aStart.y ) )
        return 0;

    int distance    = INT_MAX;
    int polycount   = GetContoursCount();

    for( int icont = 0; icont < polycount; icont++ )
    {
        int ic_start    = GetContourStart( icont );
        int ic_end      = GetContourEnd( icont );

        // now test spacing between area outline and segment
        for( int ic2 = ic_start; ic2 <= ic_end; ic2++ )
        {
            int bx1 = GetX( ic2 );
            int by1 = GetY( ic2 );
            int bx2, by2;

            if( ic2 == ic_end )
            {
                bx2 = GetX( ic_start );
                by2 = GetY( ic_start );
            }
            else
            {
                bx2 = GetX( ic2 + 1 );
                by2 = GetY( ic2 + 1 );
            }

            int d = GetClearanceBetweenSegments( bx1, by1, bx2, by2, 0,
                                                 aStart.x, aStart.y, aEnd.x, aEnd.y,
                                                 aWidth,
                                                 1,    // min clearance, should be > 0
                                                 NULL, NULL );

            if( distance > d )
                distance = d;

            if( distance <= 0 )
                return 0;
        }
    }

    return distance;
}


/*
 * Function Distance
 * Calculates the distance between a point and polygon (with holes):
 * param aPoint is the coordinate of the point.
 * return distance between the point and outline.
 *               0 if the point is inside
 */
int CPolyLine::Distance( const wxPoint& aPoint )
{
    // We calculate the dist between the point and each outline segment
    // If the point is inside the outline, the dist is 0.
    if( TestPointInside( aPoint.x, aPoint.y ) )
        return 0;

    int distance    = INT_MAX;
    int polycount   = GetContoursCount();

    for( int icont = 0; icont < polycount; icont++ )
    {
        int ic_start    = GetContourStart( icont );
        int ic_end      = GetContourEnd( icont );

        // now test spacing between area outline and segment
        for( int ic2 = ic_start; ic2 <= ic_end; ic2++ )
        {
            int bx1 = GetX( ic2 );
            int by1 = GetY( ic2 );
            int bx2, by2;

            if( ic2 == ic_end )
            {
                bx2 = GetX( ic_start );
                by2 = GetY( ic_start );
            }
            else
            {
                bx2 = GetX( ic2 + 1 );
                by2 = GetY( ic2 + 1 );
            }

            int d = KiROUND( GetPointToLineSegmentDistance( aPoint.x, aPoint.y,
                                                            bx1, by1, bx2, by2 ) );

            if( distance > d )
                distance = d;

            if( distance <= 0 )
                return 0;
        }
    }

    return distance;
}


/*
 * test is the point aPos is near (< aDistMax ) a vertex
 * return int = the index of the first corner of the vertex, or -1 if not found.
 */
int CPolyLine::HitTestForEdge( const wxPoint& aPos, int aDistMax ) const
{
    unsigned lim = m_CornersList.GetCornersCount();
    int corner = -1;     // Set to not found
    unsigned first_corner_pos = 0;

    for( unsigned item_pos = 0; item_pos < lim; item_pos++ )
    {
        unsigned end_segm = item_pos + 1;

        /* the last corner of the current outline is tested
         * the last segment of the current outline starts at current corner, and ends
         * at the first corner of the outline
         */
        if( m_CornersList.IsEndContour ( item_pos ) || end_segm >= lim )
        {
            unsigned tmp = first_corner_pos;
            first_corner_pos = end_segm;    // first_corner_pos is the beginning of next outline
            end_segm = tmp;                 // end_segm is the beginning of the current outline
        }

        // test the dist between segment and ref point
        int dist = KiROUND( GetPointToLineSegmentDistance(
                    aPos.x, aPos.y,
                    m_CornersList.GetX( item_pos ),
                    m_CornersList.GetY( item_pos ),
                    m_CornersList.GetX( end_segm ),
                    m_CornersList.GetY( end_segm ) ) );

        if( dist < aDistMax )
        {
            corner = item_pos;
            aDistMax = dist;
        }
    }

    return corner;
}


/*
 * test is the point aPos is near (< aDistMax ) a corner
 * return int = the index of corner of the, or -1 if not found.
 */
int CPolyLine::HitTestForCorner( const wxPoint& aPos, int aDistMax ) const
{
    int corner = -1;         // Set to not found
    wxPoint delta;
    unsigned lim = m_CornersList.GetCornersCount();

    for( unsigned item_pos = 0; item_pos < lim; item_pos++ )
    {
        delta.x = aPos.x - m_CornersList.GetX( item_pos );
        delta.y = aPos.y - m_CornersList.GetY( item_pos );

        // Calculate a distance:
        int dist = std::max( abs( delta.x ), abs( delta.y ) );

        if( dist < aDistMax )  // this corner is a candidate:
        {
            corner = item_pos;
            aDistMax = dist;
        }
    }

    return corner;
}


/**
 * Function IsPolygonSelfIntersecting
 * Test a CPolyLine for self-intersection of vertex (all contours).
 *
 * @return :
 *  false if no intersecting sides
 *  true if intersecting sides
 * When a CPolyLine is self intersectic, it need to be normalized.
 * (converted to non intersecting polygons)
 */
bool CPolyLine::IsPolygonSelfIntersecting()
{
    // first, check for sides intersecting other sides
    int n_cont  = GetContoursCount();

    // make bounding rect for each contour
    std::vector<EDA_RECT> cr;
    cr.reserve( n_cont );

    for( int icont = 0; icont<n_cont; icont++ )
        cr.push_back( GetBoundingBox( icont ) );

    for( int icont = 0; icont<n_cont; icont++ )
    {
        int is_start = GetContourStart( icont );
        int is_end   = GetContourEnd( icont );

        for( int is = is_start; is<=is_end; is++ )
        {
            int is_prev = is - 1;

            if( is_prev < is_start )
                is_prev = is_end;

            int is_next = is + 1;

            if( is_next > is_end )
                is_next = is_start;

            int x1i   = GetX( is );
            int y1i   = GetY( is );
            int x1f   = GetX( is_next );
            int y1f   = GetY( is_next );

            // check for intersection with any other sides
            for( int icont2 = icont; icont2 < n_cont; icont2++ )
            {
                if( !cr[icont].Intersects( cr[icont2] ) )
                {
                    // rectangles don't overlap, do nothing
                }
                else
                {
                    int is2_start = GetContourStart( icont2 );
                    int is2_end   = GetContourEnd( icont2 );

                    for( int is2 = is2_start; is2<=is2_end; is2++ )
                    {
                        int is2_prev = is2 - 1;

                        if( is2_prev < is2_start )
                            is2_prev = is2_end;

                        int is2_next = is2 + 1;

                        if( is2_next > is2_end )
                            is2_next = is2_start;

                        if( icont != icont2
                           || ( is2 != is && is2 != is_prev && is2 != is_next &&
                                is != is2_prev && is != is2_next )
                          )
                        {
                            int x2i    = GetX( is2 );
                            int y2i    = GetY( is2 );
                            int x2f    = GetX( is2_next );
                            int y2f    = GetY( is2_next );
                            int ret    = FindSegmentIntersections( x1i, y1i, x1f, y1f,
                                                                   x2i, y2i, x2f, y2f );
                            if( ret )
                            {
                                // intersection between non-adjacent sides
                                return true;
                            }
                        }
                    }
                }
            }
        }
    }

    return false;
}


const SHAPE_POLY_SET ConvertPolyListToPolySet( const CPOLYGONS_LIST& aList )
{
    SHAPE_POLY_SET rv;

    unsigned corners_count = aList.GetCornersCount();

    // Enter main outline: this is the first contour
    unsigned ic = 0;

    if( !corners_count )
        return rv;

    int index = 0;

    while( ic < corners_count )
    {
        int hole = -1;

        if( index == 0 )
        {
            rv.NewOutline();
            hole = -1;
        }
        else
        {
            hole = rv.NewHole();
        }

        while( ic < corners_count )
        {
            rv.Append( aList.GetX( ic ), aList.GetY( ic ), 0, hole );

            if( aList.IsEndContour( ic ) )
                break;

            ic++;
        }
        ic++;

        index++;
    }

    return rv;
}


const CPOLYGONS_LIST ConvertPolySetToPolyList(const SHAPE_POLY_SET& aPolyset)
{
    CPOLYGONS_LIST list;
    CPolyPt corner, firstCorner;

    const SHAPE_POLY_SET::POLYGON& poly = aPolyset.CPolygon( 0 );

    for( unsigned int jj = 0; jj < poly.size() ; jj++ )
    {
        const SHAPE_LINE_CHAIN& path = poly[jj];

        for( int i = 0; i < path.PointCount(); i++ )
        {
            const VECTOR2I &v = path.CPoint( i );

            corner.x    = v.x;
            corner.y    = v.y;
            corner.end_contour = false;

            if( i == 0 )
                firstCorner = corner;

            list.AddCorner( corner );
        }

        firstCorner.end_contour = true;
        list.AddCorner( firstCorner );
    }

    return list;
}