diff --git a/lib/Slic3r/Fill.pm b/lib/Slic3r/Fill.pm
index b31032c9d9..edc5bfe72f 100644
--- a/lib/Slic3r/Fill.pm
+++ b/lib/Slic3r/Fill.pm
@@ -70,7 +70,7 @@ sub make_fill {
         @groups = sort { defined $a->[0]->bridge_angle ? -1 : 0 } @groups;
         
         foreach my $group (@groups) {
-            my $union = union_ex([ map $_->p, @$group ], undef, 1);
+            my $union = union_ex([ map $_->p, @$group ], 1);
             
             # subtract surfaces having a defined bridge_angle from any other
             if (@surfaces_with_bridge_angle && !defined $group->[0]->bridge_angle) {
@@ -120,7 +120,6 @@ sub make_fill {
                 (map @{$_->expolygon}, grep $_->surface_type == S_TYPE_INTERNALVOID, @surfaces),
                 (@$collapsed),
             ],
-            undef,
             1,
         )};
     }
diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index 0b601fc2a3..3e11db93bd 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -105,7 +105,7 @@ sub change_layer {
         );
     if ($self->config->avoid_crossing_perimeters) {
         $self->layer_mp(Slic3r::GCode::MotionPlanner->new(
-            islands => union_ex([ map @$_, @{$layer->slices} ], undef, 1),
+            islands => union_ex([ map @$_, @{$layer->slices} ], 1),
         ));
     }
     
diff --git a/lib/Slic3r/Geometry/Clipper.pm b/lib/Slic3r/Geometry/Clipper.pm
index 164d5fc3e0..772ca2089b 100644
--- a/lib/Slic3r/Geometry/Clipper.pm
+++ b/lib/Slic3r/Geometry/Clipper.pm
@@ -57,18 +57,6 @@ sub diff {
     ];
 }
 
-sub union_ex {
-    my ($polygons, $jointype, $safety_offset) = @_;
-    $jointype = PFT_NONZERO unless defined $jointype;
-    $clipper->clear;
-    $polygons = $polygons->arrayref if ref $polygons eq 'Slic3r::ExPolygon';
-    $clipper->add_subject_polygons($safety_offset ? _convert(safety_offset($polygons)) : _convert($polygons));
-    return [
-        map Slic3r::ExPolygon->new($_->{outer}, @{$_->{holes}}),
-            @{ $clipper->ex_execute(CT_UNION, $jointype, $jointype) },
-    ];
-}
-
 sub union_pt {
     my ($polygons, $jointype, $safety_offset) = @_;
     $jointype = PFT_NONZERO unless defined $jointype;
@@ -77,18 +65,6 @@ sub union_pt {
     return $clipper->pt_execute(CT_UNION, $jointype, $jointype);
 }
 
-sub intersection_ex {
-    my ($subject, $clip, $jointype, $safety_offset) = @_;
-    $jointype = PFT_NONZERO unless defined $jointype;
-    $clipper->clear;
-    $clipper->add_subject_polygons(_convert($subject));
-    $clipper->add_clip_polygons($safety_offset ? _convert(safety_offset($clip)) : _convert($clip));
-    return [
-        map Slic3r::ExPolygon->new($_->{outer}, @{$_->{holes}}),
-            @{ $clipper->ex_execute(CT_INTERSECTION, $jointype, $jointype) },
-    ];
-}
-
 sub intersection {
     my ($subject, $clip, $jointype, $safety_offset) = @_;
     $jointype = PFT_NONZERO unless defined $jointype;
@@ -101,18 +77,6 @@ sub intersection {
     ];
 }
 
-sub xor_ex {
-    my ($subject, $clip, $jointype) = @_;
-    $jointype = PFT_NONZERO unless defined $jointype;
-    $clipper->clear;
-    $clipper->add_subject_polygons(_convert($subject));
-    $clipper->add_clip_polygons(_convert($clip));
-    return [
-        map Slic3r::ExPolygon->new($_->{outer}, @{$_->{holes}}),
-            @{ $clipper->ex_execute(CT_XOR, $jointype, $jointype) },
-    ];
-}
-
 sub collapse_ex {
     my ($polygons, $width) = @_;
     return offset2_ex($polygons, -$width/2, +$width/2);
diff --git a/lib/Slic3r/Layer/Region.pm b/lib/Slic3r/Layer/Region.pm
index 4ef1f2ac15..ec8da4e3d2 100644
--- a/lib/Slic3r/Layer/Region.pm
+++ b/lib/Slic3r/Layer/Region.pm
@@ -418,13 +418,11 @@ sub process_external_surfaces {
         @top = @{intersection_ex(
             [ Slic3r::Geometry::Clipper::offset([ map $_->p, @top ], +$margin) ],
             [ map $_->p, @fill_boundaries ],
-            undef,
             1,  # to ensure adjacent expolygons are unified
         )};
         @bottom = @{intersection_ex(
             [ Slic3r::Geometry::Clipper::offset([ map $_->p, @bottom ], +$margin) ],
             [ map $_->p, @fill_boundaries ],
-            undef,
             1,  # to ensure adjacent expolygons are unified
         )};
         
@@ -526,7 +524,6 @@ sub _detect_bridges {
             my $anchors = intersection_ex(
                 [ $surface->p ],
                 [ map @$_, @lower ],
-                undef,
                 1,  # safety offset required to avoid Clipper from detecting empty intersection while Boost actually found some @edges
             );
             
diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index c78518aa01..9e33dca7f9 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -610,7 +610,7 @@ sub discover_horizontal_shells {
                     my $new_internal_solid = intersection_ex(
                         [ map @$_, @$solid ],
                         [ map $_->p, grep { ($_->surface_type == S_TYPE_INTERNAL) || ($_->surface_type == S_TYPE_INTERNALSOLID) } @neighbor_fill_surfaces ],
-                        undef, 1,
+                        1,
                     );
                     next if !@$new_internal_solid;
                     
diff --git a/xs/src/ClipperUtils.cpp b/xs/src/ClipperUtils.cpp
index 82e12e06d7..15cd87c0cf 100644
--- a/xs/src/ClipperUtils.cpp
+++ b/xs/src/ClipperUtils.cpp
@@ -139,8 +139,8 @@ offset2_ex(Slic3r::Polygons &polygons, Slic3r::ExPolygons &retval, const float d
     delete output2;
 }
 
-void
-diff_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, bool safety_offset)
+inline void _clipper_ex(ClipperLib::ClipType clipType, Slic3r::Polygons &subject, 
+    Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, bool safety_offset)
 {
     // read input
     ClipperLib::Polygons* input_subject = new ClipperLib::Polygons();
@@ -150,7 +150,11 @@ diff_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &r
     
     // perform safety offset
     if (safety_offset) {
-        // SafetyOffset(*input_clip);
+        if (clipType == ClipperLib::ctUnion) {
+            // SafetyOffset(*input_subject);
+        } else {
+            // SafetyOffset(*input_clip);
+        }
     }
     
     // init Clipper
@@ -165,13 +169,35 @@ diff_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &r
     
     // perform operation
     ClipperLib::PolyTree* polytree = new ClipperLib::PolyTree();
-    clipper.Execute(ClipperLib::ctDifference, *polytree, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
+    clipper.Execute(clipType, *polytree, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
     
     // convert into ExPolygons
     PolyTreeToExPolygons(*polytree, retval);
     delete polytree;
 }
 
+void
+diff_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, bool safety_offset)
+{
+    _clipper_ex(ClipperLib::ctDifference, subject, clip, retval, safety_offset);
+}
 
+void intersection_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, 
+    bool safety_offset)
+{
+    _clipper_ex(ClipperLib::ctIntersection, subject, clip, retval, safety_offset);
+}
+
+void xor_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, 
+    bool safety_offset)
+{
+    _clipper_ex(ClipperLib::ctXor, subject, clip, retval, safety_offset);
+}
+
+void union_ex(Slic3r::Polygons &subject, Slic3r::ExPolygons &retval, bool safety_offset)
+{
+    Slic3r::Polygons p;
+    _clipper_ex(ClipperLib::ctUnion, subject, p, retval, safety_offset);
+}
 
 }
diff --git a/xs/src/ClipperUtils.hpp b/xs/src/ClipperUtils.hpp
index 37012591df..f2f4a3b72b 100644
--- a/xs/src/ClipperUtils.hpp
+++ b/xs/src/ClipperUtils.hpp
@@ -30,7 +30,15 @@ void offset2_ex(Slic3r::Polygons &polygons, Slic3r::ExPolygons &retval, const fl
     const float delta2, double scale = 100000, ClipperLib::JoinType joinType = ClipperLib::jtMiter, 
     double miterLimit = 3);
 
-void diff_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, bool safety_offset);
+inline void _clipper_ex(ClipperLib::ClipType clipType, Slic3r::Polygons &subject, 
+    Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, 
+    bool safety_offset);
+void diff_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, bool safety_offset = false);
+void intersection_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, 
+    bool safety_offset = false);
+void xor_ex(Slic3r::Polygons &subject, Slic3r::Polygons &clip, Slic3r::ExPolygons &retval, 
+    bool safety_offset = false);
+void union_ex(Slic3r::Polygons &subject, Slic3r::ExPolygons &retval, bool safety_offset = false);
 
 }
 
diff --git a/xs/xsp/Clipper.xsp b/xs/xsp/Clipper.xsp
index 08fdfa3d72..3907cd10cb 100644
--- a/xs/xsp/Clipper.xsp
+++ b/xs/xsp/Clipper.xsp
@@ -45,4 +45,33 @@ diff_ex(subject, clip, safety_offset = false)
     OUTPUT:
         RETVAL
 
+ExPolygons
+intersection_ex(subject, clip, safety_offset = false)
+    Polygons                    subject
+    Polygons                    clip
+    bool                        safety_offset
+    CODE:
+        intersection_ex(subject, clip, RETVAL, safety_offset);
+    OUTPUT:
+        RETVAL
+
+ExPolygons
+xor_ex(subject, clip, safety_offset = false)
+    Polygons                    subject
+    Polygons                    clip
+    bool                        safety_offset
+    CODE:
+        xor_ex(subject, clip, RETVAL, safety_offset);
+    OUTPUT:
+        RETVAL
+
+ExPolygons
+union_ex(subject, safety_offset = false)
+    Polygons                    subject
+    bool                        safety_offset
+    CODE:
+        union_ex(subject, RETVAL, safety_offset);
+    OUTPUT:
+        RETVAL
+
 %}
diff --git a/xs/xsp/my.map b/xs/xsp/my.map
index 81950a13d4..d26060ede1 100644
--- a/xs/xsp/my.map
+++ b/xs/xsp/my.map
@@ -14,6 +14,7 @@ SurfaceCollection*      O_OBJECT
 ExtrusionRole     T_UV
 SurfaceType     T_UV
 ClipperLib::JoinType		T_UV
+ClipperLib::PolyFillType		T_UV
 
 Lines           T_ARRAYREF
 Polygons        T_ARRAYREF