Remove residual uses of Boost for line clipping

lib/Slic3r/ExPolygon.pm

@@ -110,8 +110,8 @@ sub _medial_axis_clip {
             push @$covered, map $grow->($_, $width*1.1), @$clipped;
             
             # if the first remaining segment is connected to the last polyline, append it 
-            # to that -- NOTE: this assumes that multi_linestring_multi_polygon_difference()
+            # to that -- FIXME: this assumes that diff_pl()
-            # preserved the orientation of the input linestring
+            # preserved the orientation of the input linestring but this is not generally true
             if (@polylines && @$clipped && $clipped->[0]->first_point->distance_to($polylines[-1]->last_point) <= $width/10) {
                 $polylines[-1]->append_polyline(shift @$clipped);
             }

lib/Slic3r/Print/SupportMaterial.pm

@@ -4,7 +4,8 @@ use Moo;
 use List::Util qw(sum min max);
 use Slic3r::ExtrusionPath ':roles';
 use Slic3r::Geometry qw(scale scaled_epsilon PI rad2deg deg2rad);
-use Slic3r::Geometry::Clipper qw(offset diff union union_ex intersection offset_ex offset2);
+use Slic3r::Geometry::Clipper qw(offset diff union union_ex intersection offset_ex offset2
+    intersection_pl);
 use Slic3r::Surface ':types';
 
 has 'config' => (is => 'rw', required => 1);
@@ -442,11 +443,11 @@ sub generate_toolpaths {
                 
                 # only consider the loops facing the overhang
                 {
-                    my $overhang_with_margin = offset_ex($overhang, +$flow->scaled_width/2);
+                    my $overhang_with_margin = offset($overhang, +$flow->scaled_width/2);
                     @external_loops = grep {
-                        @{ Boost::Geometry::Utils::multi_polygon_multi_linestring_intersection(
+                        @{intersection_pl(
-                            [ map $_->pp, @$overhang_with_margin ],
+                            [ $_->split_at_first_point ],
-                            [ $_->split_at_first_point->pp ],
+                            $overhang_with_margin,
                         )}
                     } @external_loops;
                 }
@@ -467,10 +468,9 @@ sub generate_toolpaths {
             }
             
             # clip such loops to the side oriented towards the object
-            @loops = map Slic3r::Polyline->new(@$_),
+            @loops = @{intersection_pl(
-                @{ Boost::Geometry::Utils::multi_polygon_multi_linestring_intersection(
+                [ map $_->split_at_first_point, @loops ],
-                    [ map $_->pp, @{offset_ex($overhang, +scale MARGIN)} ],
+                offset($overhang, +scale MARGIN),
-                    [ map $_->split_at_first_point->pp, @loops ],
             )};
             
             # add the contact infill area to the interface area

lib/Slic3r/Test/SectionCut.pm

@@ -3,7 +3,7 @@ use Moo;
 
 use List::Util qw(first max);
 use Slic3r::Geometry qw(X Y A B X1 Y1 X2 Y2 unscale);
-use Slic3r::Geometry::Clipper qw(union_ex);
+use Slic3r::Geometry::Clipper qw(union_ex intersection_pl);
 use SVG;
 
 has 'scale' => (is => 'ro', default => sub {30});
@@ -17,7 +17,7 @@ sub _build_line {
     
     my $bb = $self->print->bounding_box;
     my $y = $bb->size->[Y] * $self->y_percent;
-    return [ [ $bb->x_min, $y ], [ $bb->x_max, $y ] ]
+    return Slic3r::Line->new([ $bb->x_min, $y ], [ $bb->x_max, $y ]);
 }
 
 sub export_svg {
@@ -91,9 +91,9 @@ sub _plot {
                 
                 foreach my $path (@paths) {
                     foreach my $line (@{$path->lines}) {
-                        my @intersections = @{ Boost::Geometry::Utils::polygon_multi_linestring_intersection(
+                        my @intersections = @{intersection_pl(
-                            Slic3r::ExPolygon->new(@{$line->grow(Slic3r::Geometry::scale $path->flow_spacing/2)})->pp,
+                            [ $self->line->as_polyline ],
-                            [ $self->line ],
+                            $line->grow(Slic3r::Geometry::scale $path->flow_spacing/2),
                         )};
                         die "Intersection has more than two points!\n" if first { @$_ > 2 } @intersections;
                         

utils/gcode_sectioncut.pl

@@ -80,9 +80,9 @@ my %opt = (
     # draw paths
     foreach my $z (sort keys %paths) {
         foreach my $line (@{ $paths{$z} }) {
-            my @intersections = @{ Boost::Geometry::Utils::polygon_multi_linestring_intersection(
+            my @intersections = @{intersection_pl(
-                Slic3r::ExPolygon->new(_grow($line, $opt{extrusion_width}/2)),
                 [ $section_line ],
+                [ _grow($line, $opt{extrusion_width}/2) ],
             )};
             
             $g->rectangle(