Esempio n. 1
0
const SHAPE_LINE_CHAIN SegmentHull ( const SHAPE_SEGMENT& aSeg, int aClearance,
                                     int aWalkaroundThickness )
{
    int d = aSeg.GetWidth() / 2 + aClearance + aWalkaroundThickness / 2 + HULL_MARGIN;
    int x = (int)( 2.0 / ( 1.0 + M_SQRT2 ) * d );

    const VECTOR2I a = aSeg.GetSeg().A;
    const VECTOR2I b = aSeg.GetSeg().B;

    VECTOR2I dir = b - a;
    VECTOR2I p0 = dir.Perpendicular().Resize( d );
    VECTOR2I ds = dir.Perpendicular().Resize( x / 2 );
    VECTOR2I pd = dir.Resize( x / 2 );
    VECTOR2I dp = dir.Resize( d );

    SHAPE_LINE_CHAIN s;

    s.SetClosed( true );

    s.Append( b + p0 + pd );
    s.Append( b + dp + ds );
    s.Append( b + dp - ds );
    s.Append( b - p0 + pd );
    s.Append( a - p0 - pd );
    s.Append( a - dp - ds );
    s.Append( a - dp + ds );
    s.Append( a + p0 - pd );

    // make sure the hull outline is always clockwise
    if( s.CSegment( 0 ).Side( a ) < 0 )
        return s.Reverse();
    else
        return s;
}
bool SHAPE_POLY_SET::Parse( std::stringstream& aStream )
{
    std::string tmp;

    aStream >> tmp;

    if( tmp != "polyset" )
        return false;

    aStream >> tmp;

    int n_polys = atoi( tmp.c_str() );

    if( n_polys < 0 )
        return false;

    for( int i = 0; i < n_polys; i++ )
    {
        POLYGON paths;

        aStream >> tmp;

        if( tmp != "poly" )
            return false;

        aStream >> tmp;
        int n_outlines = atoi( tmp.c_str() );

        if( n_outlines < 0 )
            return false;

        for( int j = 0; j < n_outlines; j++ )
        {
            SHAPE_LINE_CHAIN outline;

            outline.SetClosed( true );

            aStream >> tmp;
            int n_vertices = atoi( tmp.c_str() );
            for( int v = 0; v < n_vertices; v++ )
            {
                VECTOR2I p;

                aStream >> tmp; p.x = atoi( tmp.c_str() );
                aStream >> tmp; p.y = atoi( tmp.c_str() );
                outline.Append( p );
            }

            paths.push_back( outline );
        }

        m_polys.push_back( paths );
    }
    return true;
}
Esempio n. 3
0
const SHAPE_LINE_CHAIN ConvexHull( const SHAPE_CONVEX& aConvex, int aClearance )
{
    // this defines the horizontal and vertical lines in the hull octagon
    BOX2I box = aConvex.BBox( aClearance + HULL_MARGIN );
    box.Normalize();

    SEG topline = SEG( VECTOR2I( box.GetX(), box.GetY() + box.GetHeight() ),
                       VECTOR2I( box.GetX() + box.GetWidth(), box.GetY() + box.GetHeight() ) );
    SEG rightline = SEG( VECTOR2I( box.GetX() + box.GetWidth(), box.GetY() + box.GetHeight() ),
                         VECTOR2I( box.GetX() + box.GetWidth(), box.GetY() ) );
    SEG bottomline = SEG( VECTOR2I( box.GetX() + box.GetWidth(), box.GetY() ),
             box.GetOrigin() );
    SEG leftline = SEG( box.GetOrigin(), VECTOR2I( box.GetX(), box.GetY() + box.GetHeight() ) );

    const SHAPE_LINE_CHAIN& vertices = aConvex.Vertices();

    // top right diagonal
    VECTOR2I corner = box.GetOrigin() + box.GetSize();
    SEG toprightline = SEG( corner,
                            corner + VECTOR2I( box.GetHeight(), -box.GetHeight() ) );
    MoveDiagonal( toprightline, vertices, aClearance );

    // bottom right diagonal
    corner = box.GetOrigin() + VECTOR2I( box.GetWidth(), 0 );
    SEG bottomrightline = SEG( corner + VECTOR2I( box.GetHeight(), box.GetHeight() ),
                               corner );
    MoveDiagonal( bottomrightline, vertices, aClearance );

    // bottom left diagonal
    corner = box.GetOrigin();
    SEG bottomleftline = SEG( corner,
                              corner + VECTOR2I( -box.GetHeight(), box.GetHeight() ) );
    MoveDiagonal( bottomleftline, vertices, aClearance );

    // top left diagonal
    corner = box.GetOrigin() + VECTOR2I( 0, box.GetHeight() );
    SEG topleftline = SEG( corner + VECTOR2I( -box.GetHeight(), -box.GetHeight() ),
                           corner );
    MoveDiagonal( topleftline, vertices, aClearance );

    SHAPE_LINE_CHAIN octagon;
    octagon.SetClosed( true );

    octagon.Append( *leftline.IntersectLines( bottomleftline ) );
    octagon.Append( *bottomline.IntersectLines( bottomleftline ) );
    octagon.Append( *bottomline.IntersectLines( bottomrightline ) );
    octagon.Append( *rightline.IntersectLines( bottomrightline ) );
    octagon.Append( *rightline.IntersectLines( toprightline ) );
    octagon.Append( *topline.IntersectLines( toprightline ) );
    octagon.Append( *topline.IntersectLines( topleftline ) );
    octagon.Append( *leftline.IntersectLines( topleftline ) );

    return octagon;
}
Esempio n. 4
0
const SHAPE_LINE_CHAIN OctagonalHull( const VECTOR2I& aP0, const VECTOR2I& aSize,
                                      int aClearance, int aChamfer )
{
    SHAPE_LINE_CHAIN s;

    s.SetClosed( true );

    s.Append( aP0.x - aClearance, aP0.y - aClearance + aChamfer );
    s.Append( aP0.x - aClearance + aChamfer, aP0.y - aClearance );
    s.Append( aP0.x + aSize.x + aClearance - aChamfer, aP0.y - aClearance );
    s.Append( aP0.x + aSize.x + aClearance, aP0.y - aClearance + aChamfer );
    s.Append( aP0.x + aSize.x + aClearance, aP0.y + aSize.y + aClearance - aChamfer );
    s.Append( aP0.x + aSize.x + aClearance - aChamfer, aP0.y + aSize.y + aClearance );
    s.Append( aP0.x - aClearance + aChamfer, aP0.y + aSize.y + aClearance );
    s.Append( aP0.x - aClearance, aP0.y + aSize.y + aClearance - aChamfer );

    return s;
}
// This is the same function as in board_items_to_polygon_shape_transform.cpp
// but it adds the rect/trapezoid shapes with a different winding
void CINFO3D_VISU::buildPadShapePolygon( const D_PAD* aPad,
                                         SHAPE_POLY_SET& aCornerBuffer,
                                         wxSize aInflateValue,
                                         int aSegmentsPerCircle,
                                         double aCorrectionFactor ) const
{
    wxPoint corners[4];
    wxPoint PadShapePos = aPad->ShapePos(); /* Note: for pad having a shape offset,
                                             * the pad position is NOT the shape position */
    switch( aPad->GetShape() )
    {
    case PAD_SHAPE_CIRCLE:
    case PAD_SHAPE_OVAL:
    case PAD_SHAPE_ROUNDRECT:
        aPad->TransformShapeWithClearanceToPolygon( aCornerBuffer, aInflateValue.x,
                                                    aSegmentsPerCircle, aCorrectionFactor );
        break;

    case PAD_SHAPE_TRAPEZOID:
    case PAD_SHAPE_RECT:
    {
        SHAPE_LINE_CHAIN aLineChain;

        aPad->BuildPadPolygon( corners, aInflateValue, aPad->GetOrientation() );

        for( int ii = 0; ii < 4; ++ii )
        {
            corners[3-ii] += PadShapePos;          // Shift origin to position
            aLineChain.Append( corners[3-ii].x, corners[3-ii].y );
        }

        aLineChain.SetClosed( true );

        aCornerBuffer.AddOutline( aLineChain );
    }
        break;

    default:
        wxFAIL_MSG( wxT( "CINFO3D_VISU::buildPadShapePolygon: found a not implemented pad shape (new shape?)" ) );
        break;
    }
}
void GRID_HELPER::computeAnchors( BOARD_ITEM* aItem, const VECTOR2I& aRefPos )
{
    VECTOR2I origin;

    switch( aItem->Type() )
    {
        case PCB_MODULE_T:
        {
            MODULE* mod = static_cast<MODULE*>( aItem );
            addAnchor( mod->GetPosition(), ORIGIN | SNAPPABLE, mod );

            for( D_PAD* pad = mod->Pads(); pad; pad = pad->Next() )
                addAnchor( pad->GetPosition(), CORNER | SNAPPABLE, pad );

            break;
        }


        case PCB_PAD_T:
        {
            D_PAD* pad = static_cast<D_PAD*>( aItem );
            addAnchor( pad->GetPosition(), CORNER | SNAPPABLE, pad );

            break;
        }

        case PCB_MODULE_EDGE_T:
        case PCB_LINE_T:
        {
            DRAWSEGMENT* dseg = static_cast<DRAWSEGMENT*>( aItem );
            VECTOR2I start = dseg->GetStart();
            VECTOR2I end = dseg->GetEnd();
            //LAYER_ID layer = dseg->GetLayer();

            switch( dseg->GetShape() )
            {
                case S_CIRCLE:
                {
                    int r = ( start - end ).EuclideanNorm();

                    addAnchor( start, ORIGIN | SNAPPABLE, dseg );
                    addAnchor( start + VECTOR2I( -r, 0 ), OUTLINE | SNAPPABLE, dseg );
                    addAnchor( start + VECTOR2I( r, 0 ), OUTLINE | SNAPPABLE, dseg );
                    addAnchor( start + VECTOR2I( 0, -r ), OUTLINE | SNAPPABLE, dseg );
                    addAnchor( start + VECTOR2I( 0, r ), OUTLINE | SNAPPABLE, dseg );
                    break;
                }

                case S_ARC:
                {
                    origin = dseg->GetCenter();
                    addAnchor( dseg->GetArcStart(), CORNER | SNAPPABLE, dseg );
                    addAnchor( dseg->GetArcEnd(), CORNER | SNAPPABLE, dseg );
                    addAnchor( origin, ORIGIN | SNAPPABLE, dseg );
                    break;
                }

                case S_SEGMENT:
                {
                    origin.x = start.x + ( start.x - end.x ) / 2;
                    origin.y = start.y + ( start.y - end.y ) / 2;
                    addAnchor( start, CORNER | SNAPPABLE, dseg );
                    addAnchor( end, CORNER | SNAPPABLE, dseg );
                    addAnchor( origin, ORIGIN, dseg );
                    break;
                }

                default:
                {
                    origin = dseg->GetStart();
                    addAnchor( origin, ORIGIN | SNAPPABLE, dseg );
                    break;
                }
            }
            break;
        }

        case PCB_TRACE_T:
        {
            TRACK* track = static_cast<TRACK*>( aItem );
            VECTOR2I start = track->GetStart();
            VECTOR2I end = track->GetEnd();
            origin.x = start.x + ( start.x - end.x ) / 2;
            origin.y = start.y + ( start.y - end.y ) / 2;
            addAnchor( start, CORNER | SNAPPABLE, track );
            addAnchor( end, CORNER | SNAPPABLE, track );
            addAnchor( origin, ORIGIN, track);
            break;
        }

        case PCB_VIA_T:
            addAnchor( aItem->GetPosition(), CORNER | SNAPPABLE, aItem );
            break;

        case PCB_ZONE_AREA_T:
        {
            const CPolyLine* outline = static_cast<const ZONE_CONTAINER*>( aItem )->Outline();
            int cornersCount = outline->GetCornersCount();

            SHAPE_LINE_CHAIN lc;
            lc.SetClosed( true );

            for( int i = 0; i < cornersCount; ++i )
            {
                const VECTOR2I p ( outline->GetPos( i ) );
                addAnchor( p, CORNER, aItem );
                lc.Append( p );
            }

            addAnchor( lc.NearestPoint( aRefPos ), OUTLINE, aItem );

            break;
        }

        case PCB_MODULE_TEXT_T:
        case PCB_TEXT_T:
            addAnchor( aItem->GetPosition(), ORIGIN, aItem );
        default:

        break;
   }
}
Esempio n. 7
0
void Convert_path_polygon_to_polygon_blocks_and_dummy_blocks(
        const SHAPE_POLY_SET &aMainPath,
        CGENERICCONTAINER2D &aDstContainer,
        float aBiuTo3DunitsScale,
        float aDivFactor,
        const BOARD_ITEM &aBoardItem )
{
    BOX2I pathBounds = aMainPath.BBox();

    // Get the path

    wxASSERT( aMainPath.OutlineCount() == 1 );
    const SHAPE_POLY_SET::POLYGON& curr_polywithholes = aMainPath.CPolygon( 0 );

    wxASSERT( curr_polywithholes.size() == 1 );
    const SHAPE_LINE_CHAIN& path = curr_polywithholes[0];   // a simple polygon

    // Convert the points to segments class
    CBBOX2D bbox;
    bbox.Reset();

    // Contains the main list of segments and each segment normal interpolated
    SEGMENTS_WIDTH_NORMALS segments_and_normals;

    // Contains a closed polygon used to calc if points are inside
    SEGMENTS segments;

    segments_and_normals.resize( path.PointCount() );
    segments.resize( path.PointCount() );

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

        const SFVEC2F point ( (float)( a.x) * aBiuTo3DunitsScale,
                              (float)(-a.y) * aBiuTo3DunitsScale );

        bbox.Union( point );
        segments_and_normals[i].m_Start = point;
        segments[i].m_Start = point;
    }

    bbox.ScaleNextUp();


    // Calc the slopes, normals and some statistics about this polygon
    unsigned int i;
    unsigned int j = segments_and_normals.size() - 1;

    // Temporary normal to the segment, it will later be used for interpolation
    std::vector< SFVEC2F >  tmpSegmentNormals;
    tmpSegmentNormals.resize( segments_and_normals.size() );

    float medOfTheSquaresSegmentLength = 0.0f;
#ifdef PRINT_STATISTICS_3D_VIEWER
    float minLength = FLT_MAX;
#endif

    for( i = 0; i < segments_and_normals.size(); j = i++ )
    {
        const SFVEC2F slope = segments_and_normals[j].m_Start -
                              segments_and_normals[i].m_Start;

        segments_and_normals[i].m_Precalc_slope = slope;

        // Calculate constants for each segment
        segments[i].m_inv_JY_minus_IY = 1.0f / ( segments_and_normals[j].m_Start.y -
                                                 segments_and_normals[i].m_Start.y );

        segments[i].m_JX_minus_IX = ( segments_and_normals[j].m_Start.x -
                                      segments_and_normals[i].m_Start.x );

        // The normal orientation expect a fixed polygon orientation (!TODO: which one?)
        //tmpSegmentNormals[i] = glm::normalize( SFVEC2F( -slope.y, +slope.x ) );
        tmpSegmentNormals[i] = glm::normalize( SFVEC2F( slope.y, -slope.x ) );

        const float length = slope.x * slope.x + slope.y * slope.y;

#ifdef PRINT_STATISTICS_3D_VIEWER
        if( length < minLength )
            minLength = length;
#endif

        medOfTheSquaresSegmentLength += length;
    }

#ifdef PRINT_STATISTICS_3D_VIEWER
    float minSegmentLength = sqrt( minLength );
#endif

    // This calc an approximation of medium lengths, that will be used to calc
    // the size of the division.
    medOfTheSquaresSegmentLength /= segments_and_normals.size();
    medOfTheSquaresSegmentLength = sqrt( medOfTheSquaresSegmentLength );


    // Compute the normal interpolation
    // If calculate the dot between the segments, if they are above/below some
    // threshould it will not interpolated it (ex: if you are in a edge corner
    // or in a smooth transaction)
    j = segments_and_normals.size() - 1;
    for( i = 0; i < segments_and_normals.size(); j = i++ )
    {
        const SFVEC2F normalBeforeSeg = tmpSegmentNormals[j];
        const SFVEC2F normalSeg       = tmpSegmentNormals[i];
        const SFVEC2F normalAfterSeg  = tmpSegmentNormals[ (i + 1) %
                                                           segments_and_normals.size() ];

        const float dotBefore = glm::dot( normalBeforeSeg, normalSeg );
        const float dotAfter  = glm::dot( normalAfterSeg,  normalSeg );

        if( dotBefore < 0.7f )
            segments_and_normals[i].m_Normals.m_Start = normalSeg;
        else
            segments_and_normals[i].m_Normals.m_Start =
                glm::normalize( (((normalBeforeSeg * dotBefore ) + normalSeg) * 0.5f) );

        if( dotAfter < 0.7f )
            segments_and_normals[i].m_Normals.m_End = normalSeg;
        else
            segments_and_normals[i].m_Normals.m_End =
                glm::normalize( (((normalAfterSeg  * dotAfter  ) + normalSeg) * 0.5f) );
    }

    if( aDivFactor == 0.0f )
        aDivFactor = medOfTheSquaresSegmentLength;

    SFVEC2UI grid_divisions;
    grid_divisions.x = (unsigned int)( (bbox.GetExtent().x / aDivFactor) );
    grid_divisions.y = (unsigned int)( (bbox.GetExtent().y / aDivFactor) );

    grid_divisions = glm::clamp( grid_divisions ,
                                 SFVEC2UI( 1, 1 ),
                                 SFVEC2UI( MAX_NR_DIVISIONS, MAX_NR_DIVISIONS ) );

    // Calculate the steps advance of the grid
    SFVEC2F blockAdvance;

    blockAdvance.x = bbox.GetExtent().x / (float)grid_divisions.x;
    blockAdvance.y = bbox.GetExtent().y / (float)grid_divisions.y;

    wxASSERT( blockAdvance.x > 0.0f );
    wxASSERT( blockAdvance.y > 0.0f );

    const int leftToRight_inc = (pathBounds.GetRight()  - pathBounds.GetLeft()) /
                                grid_divisions.x;

    const int topToBottom_inc = (pathBounds.GetBottom() - pathBounds.GetTop())  /
                                grid_divisions.y;

    // Statistics
    unsigned int stats_n_empty_blocks = 0;
    unsigned int stats_n_dummy_blocks = 0;
    unsigned int stats_n_poly_blocks = 0;
    unsigned int stats_sum_size_of_polygons = 0;


    // Step by each block of a grid trying to extract segments and create
    // polygon blocks

    int topToBottom = pathBounds.GetTop();
    float blockY = bbox.Max().y;

    for( unsigned int iy = 0; iy < grid_divisions.y; iy++ )
    {

        int leftToRight = pathBounds.GetLeft();
        float blockX = bbox.Min().x;

        for( unsigned int ix = 0; ix < grid_divisions.x; ix++ )
        {
            CBBOX2D blockBox( SFVEC2F( blockX,
                                       blockY - blockAdvance.y ),
                              SFVEC2F( blockX + blockAdvance.x,
                                       blockY                  ) );

            // Make the box large to it will catch (intersect) the edges
            blockBox.ScaleNextUp();
            blockBox.ScaleNextUp();
            blockBox.ScaleNextUp();

            SEGMENTS_WIDTH_NORMALS extractedSegments;

            extractPathsFrom( segments_and_normals, blockBox, extractedSegments );


            if( extractedSegments.empty() )
            {

                SFVEC2F p1( blockBox.Min().x, blockBox.Min().y );
                SFVEC2F p2( blockBox.Max().x, blockBox.Min().y );
                SFVEC2F p3( blockBox.Max().x, blockBox.Max().y );
                SFVEC2F p4( blockBox.Min().x, blockBox.Max().y );

                if( polygon_IsPointInside( segments, p1 ) ||
                    polygon_IsPointInside( segments, p2 ) ||
                    polygon_IsPointInside( segments, p3 ) ||
                    polygon_IsPointInside( segments, p4 ) )
                {
                    // In this case, the segments are not intersecting the
                    // polygon, so it means that if any point is inside it,
                    // then all other are inside the polygon.
                    // This is a full bbox inside, so add a dummy box

                    aDstContainer.Add( new CDUMMYBLOCK2D( blockBox, aBoardItem ) );
                    stats_n_dummy_blocks++;
                }
                else
                {
                    // Points are outside, so this block complety missed the polygon
                    // In this case, no objects need to be added
                    stats_n_empty_blocks++;
                }
            }
            else
            {
                // At this point, the borders of polygon were intersected by the
                // bounding box, so we must calculate a new polygon that will
                // close that small block.
                // This block will be used to calculate if points are inside
                // the (sub block) polygon.

                SHAPE_POLY_SET subBlockPoly;

                SHAPE_LINE_CHAIN sb = SHAPE_LINE_CHAIN(
                                        VECTOR2I( leftToRight,
                                                  topToBottom ),
                                        VECTOR2I( leftToRight + leftToRight_inc,
                                                  topToBottom ),
                                        VECTOR2I( leftToRight + leftToRight_inc,
                                                  topToBottom + topToBottom_inc ),
                                        VECTOR2I( leftToRight,
                                                  topToBottom + topToBottom_inc ) );

                //sb.Append( leftToRight, topToBottom );
                sb.SetClosed( true );

                subBlockPoly.AddOutline( sb );

                // We need here a strictly simple polygon with outlines and holes
                SHAPE_POLY_SET solution;
                solution.BooleanIntersection( aMainPath,
                                              subBlockPoly,
                                              SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );

                OUTERS_AND_HOLES outersAndHoles;

                outersAndHoles.m_Holes.clear();
                outersAndHoles.m_Outers.clear();

                for( int idx = 0; idx < solution.OutlineCount(); idx++ )
                {
                    const SHAPE_LINE_CHAIN & outline = solution.Outline( idx );

                    SEGMENTS solutionSegment;

                    polygon_Convert( outline, solutionSegment, aBiuTo3DunitsScale );
                    outersAndHoles.m_Outers.push_back( solutionSegment );

                    stats_sum_size_of_polygons += solutionSegment.size();

                    for( int holeIdx = 0;
                         holeIdx < solution.HoleCount( idx );
                         holeIdx++ )
                    {
                        const SHAPE_LINE_CHAIN & hole = solution.Hole( idx, holeIdx );

                        polygon_Convert( hole, solutionSegment, aBiuTo3DunitsScale );
                        outersAndHoles.m_Holes.push_back( solutionSegment );
                        stats_sum_size_of_polygons += solutionSegment.size();
                    }

                }

                if( !outersAndHoles.m_Outers.empty() )
                {
                    aDstContainer.Add( new CPOLYGONBLOCK2D( extractedSegments,
                                                            outersAndHoles,
                                                            aBoardItem ) );
                    stats_n_poly_blocks++;
                }
            }

            blockX += blockAdvance.x;
            leftToRight += leftToRight_inc;
        }

        blockY -= blockAdvance.y;
        topToBottom += topToBottom_inc;
    }

#ifdef PRINT_STATISTICS_3D_VIEWER
    printf( "////////////////////////////////////////////////////////////////////////////////\n" );
    printf( "Convert_path_polygon_to_polygon_blocks_and_dummy_blocks\n" );
    printf( "  grid_divisions (%u, %u)\n", grid_divisions.x, grid_divisions.y );
    printf( "  N Total Blocks %u\n", grid_divisions.x * grid_divisions.y );
    printf( "  N Empty Blocks %u\n", stats_n_empty_blocks );
    printf( "  N Dummy Blocks %u\n", stats_n_dummy_blocks );
    printf( "  N Polyg Blocks %u\n", stats_n_poly_blocks );
    printf( "  Med N Seg Poly %u\n", stats_sum_size_of_polygons / stats_n_poly_blocks );
    printf( "  medOfTheSquaresSegmentLength %f\n", medOfTheSquaresSegmentLength );
    printf( "  minSegmentLength             %f\n", minSegmentLength );
    printf( "  aDivFactor                   %f\n", aDivFactor );
    printf( "////////////////////////////////////////////////////////////////////////////////\n" );
#endif
}
bool PNS_LINE::Walkaround( SHAPE_LINE_CHAIN aObstacle, SHAPE_LINE_CHAIN& aPre,
                           SHAPE_LINE_CHAIN& aWalk, SHAPE_LINE_CHAIN& aPost, bool aCw ) const
{
    const SHAPE_LINE_CHAIN& line ( CLine() );
    VECTOR2I ip_start;
    VECTOR2I ip_end;

    if( line.SegmentCount() < 1 )
        return false;

    if( aObstacle.PointInside( line.CPoint( 0 ) ) || aObstacle.PointInside( line.CPoint( -1 ) ) )
        return false;

    SHAPE_LINE_CHAIN::INTERSECTIONS ips, ips2;

    line.Intersect( aObstacle, ips );

    int nearest_dist = INT_MAX;
    int farthest_dist = 0;

    SHAPE_LINE_CHAIN::INTERSECTION nearest, farthest;

    for( int i = 0; i < (int) ips.size(); i++ )
    {
        const VECTOR2I p = ips[i].p;
        int dist = line.PathLength( p );

        if( dist < 0 )
            return false;

        if( dist <= nearest_dist )
        {
            nearest_dist = dist;
            nearest = ips[i];
        }

        if( dist >= farthest_dist )
        {
            farthest_dist = dist;
            farthest = ips[i];
        }
    }

    if( ips.size() <= 1 || nearest.p == farthest.p )
    {
        aPre = line;
        return true;
    }

    aPre = line.Slice( 0, nearest.our.Index() );
    aPre.Append( nearest.p );
    aPre.Simplify();

    aWalk.Clear();
    aWalk.SetClosed( false );
    aWalk.Append( nearest.p );

    int i = nearest.their.Index();

    assert( nearest.their.Index() >= 0 );
    assert( farthest.their.Index() >= 0 );

    assert( nearest_dist <= farthest_dist );

    aObstacle.Split( nearest.p );
    aObstacle.Split( farthest.p );

    int i_first = aObstacle.Find( nearest.p );
    int i_last = aObstacle.Find( farthest.p );

    i = i_first;

    while( i != i_last )
    {
        aWalk.Append( aObstacle.CPoint( i ) );
        i += ( aCw ? 1 : -1 );

        if( i < 0 )
            i = aObstacle.PointCount() - 1;
        else if( i == aObstacle.PointCount() )
            i = 0;
    }

    aWalk.Append( farthest.p );
    aWalk.Simplify();

    aPost.Clear();
    aPost.Append( farthest.p );
    aPost.Append( line.Slice( farthest.our.Index() + 1, -1 ) );
    aPost.Simplify();

    return true;
}
void SHAPE_POLY_SET::fractureSingle( POLYGON& paths )
{
    FractureEdgeSet edges;
    FractureEdgeSet border_edges;
    FractureEdge* root = NULL;

    bool first = true;

    if( paths.size() == 1 )
        return;

    int num_unconnected = 0;

    for( SHAPE_LINE_CHAIN& path : paths )
    {
        int index = 0;

        FractureEdge *prev = NULL, *first_edge = NULL;

        int x_min = std::numeric_limits<int>::max();

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

            if( p.x < x_min )
                x_min = p.x;
        }

        for( int i = 0; i < path.PointCount(); i++ )
        {
            FractureEdge* fe = new FractureEdge( first, &path, index++ );

            if( !root )
                root = fe;

            if( !first_edge )
                first_edge = fe;

            if( prev )
                prev->m_next = fe;

            if( i == path.PointCount() - 1 )
                fe->m_next = first_edge;

            prev = fe;
            edges.push_back( fe );

            if( !first )
            {
                if( fe->m_p1.x == x_min )
                    border_edges.push_back( fe );
            }

            if( !fe->m_connected )
                num_unconnected++;
        }
        first = false; // first path is always the outline
    }

    // keep connecting holes to the main outline, until there's no holes left...
    while( num_unconnected > 0 )
    {
        int x_min = std::numeric_limits<int>::max();

        FractureEdge* smallestX = NULL;

        // find the left-most hole edge and merge with the outline
        for( FractureEdgeSet::iterator i = border_edges.begin(); i != border_edges.end(); ++i )
        {
            int xt = (*i)->m_p1.x;

            if( ( xt < x_min ) && ! (*i)->m_connected )
            {
                x_min = xt;
                smallestX = *i;
            }
        }

        num_unconnected -= processEdge( edges, smallestX );
    }

    paths.clear();
    SHAPE_LINE_CHAIN newPath;

    newPath.SetClosed( true );

    FractureEdge* e;

    for( e = root; e->m_next != root; e = e->m_next )
        newPath.Append( e->m_p1 );

    newPath.Append( e->m_p1 );

    for( FractureEdgeSet::iterator i = edges.begin(); i != edges.end(); ++i )
        delete *i;

    paths.push_back( newPath );
}